FFMPEG-ALL(1)
๐ FFMPEG-ALL(1) ๐
okay so bestie, welcome to the FFMPEG-ALL(1) manual page โ aka the ffmpeg media converter glow-up guide. This is the part where we meet the main character: ffmpeg, the universal media converter that literally does it all. ๐
๐ธ NAME ๐ธ
ffmpeg โ ffmpeg media converter. That's the whole name-and-purpose vibe, no cap. ๐
โจ SYNOPSIS โจ
Here's the literal command shape, bestie:
ffmpeg [global_options] {[input_file_options] -i input_url} ...
{[output_file_options] output_url} ...
๐ DESCRIPTION ๐
okay so ffmpeg is a universal media converter. It can read a wide variety of inputs โ including live grabbing/recording devices โ then filter them and transcode them into a plethora of output formats. It's giving "one tool to rule them all," fr fr. ๐
ffmpeg reads from an arbitrary number of inputs (which can be regular files, pipes, network streams, grabbing devices, etc.), specified by the -i option, and writes to an arbitrary number of outputs, which are specified by a plain output url. Anything found on the command line which cannot be interpreted as an option is considered to be an output url. ๐
Each input or output can, in principle, contain any number of elementary streams of different types (video/audio/subtitle/attachment/data), though the allowed stream counts and/or types may be limited by the container format. Selecting which streams from which inputs will go into which output is either done automatically or with the -map option (see the Stream selection chapter). ๐ฆ
To refer to inputs/outputs in options, you must use their indices (0-based). E.g. the first input is 0, the second is 1, etc. Similarly, streams within an input/output are referred to by their indices. E.g. 2:3 refers to the fourth stream in the third input or output. Also see the Stream specifiers chapter. iykyk. ๐ซ
As a general rule, options are applied to the next specified file. Therefore, order is important, and you can have the same option on the command line multiple times. Each occurrence is then applied to the next input or output file. Exceptions from this rule are the global options (e.g. verbosity level), which should be specified first. โจ
๐จ Do not mix input and output files โ first specify all input files, then all output files. Also do not mix options which belong to different files. All options apply ONLY to the next input or output file and are reset between files. This is not a drill, bestie. ๐
Some simple examples follow. ๐
- Convert an input media file to a different format, by re-encoding media streams:
ffmpeg -i input.avi output.mp4
- Set the video bitrate of the output file to 64 kbit/s:
ffmpeg -i input.avi -b:v 64k -bufsize 64k output.mp4
- Force the frame rate of the output file to 24 fps:
ffmpeg -i input.avi -r 24 output.mp4
- Force the frame rate of the input file (valid for raw formats only) to 1 fps and the frame rate of the output file to 24 fps:
ffmpeg -r 1 -i input.m2v -r 24 output.mp4
The format option may be needed for raw input files. ๐ง
๐ฆ DETAILED DESCRIPTION ๐ฆ
okay so ffmpeg builds a transcoding pipeline out of the components listed below. The program's operation then consists of input data chunks flowing from the sources down the pipes towards the sinks, while being transformed by the components they encounter along the way. It's literally a whole assembly line, but make it media. ๐ฅ
The following kinds of components are available:
- Demuxers (short for "demultiplexers") read an input source in order to extract:
- global properties such as metadata or chapters;
- list of input elementary streams and their properties.
One demuxer instance is created for each -i option, and sends encoded packets to decoders or muxers.
In other literature, demuxers are sometimes called splitters, because their main function is splitting a file into elementary streams (though some files only contain one elementary stream).
A schematic representation of a demuxer looks like this:
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโโโโโโโโโ
โ demuxer โ โ packets for stream 0
โโโโโโโโโโโโก elementary stream 0 โโโโโโโโโโโโโโโโโโโโโโโโบ
โ โ โ
โ global โโโโโโโโโโโโโโโโโโโโโโโโโค
โpropertiesโ โ packets for stream 1
โ and โ elementary stream 1 โโโโโโโโโโโโโโโโโโโโโโโโบ
โ metadata โ โ
โ โโโโโโโโโโโโโโโโโโโโโโโโโค
โ โ โ
โ โ ........... โ
โ โ โ
โ โโโโโโโโโโโโโโโโโโโโโโโโโค
โ โ โ packets for stream N
โ โ elementary stream N โโโโโโโโโโโโโโโโโโโโโโโโบ
โ โ โ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโโโโโโโโโ
โฒ
โ
โ read from file, network stream,
โ grabbing device, etc.
โ
- Decoders receive encoded (compressed) packets for an audio, video, or subtitle elementary stream, and decode them into raw frames (arrays of pixels for video, PCM for audio). A decoder is typically associated with (and receives its input from) an elementary stream in a demuxer, but sometimes may also exist on its own (see Loopback decoders).
A schematic representation of a decoder looks like this:
โโโโโโโโโโโ
packets โ โ raw frames
โโโโโโโโโโบโ decoder โโโโโโโโโโโโโโบ
โ โ
โโโโโโโโโโโ
- Filtergraphs process and transform raw audio or video frames. A filtergraph consists of one or more individual filters linked into a graph. Filtergraphs come in two flavors โ simple and complex โ configured with the
-filterand-filter_complexoptions, respectively.
A simple filtergraph is associated with an output elementary stream; it receives the input to be filtered from a decoder and sends filtered output to that output stream's encoder.
A simple video filtergraph that performs deinterlacing (using the yadif deinterlacer) followed by resizing (using the scale filter) can look like this:
โโโโโโโโโโโโโโโโโโโโโโโโโโ
โ simple filtergraph โ
frames from โโโโโโโโโโโโโโโโโโโโโโโโโโก frames for
a decoder โ โโโโโโโโโ โโโโโโโโโ โ an encoder
โโโโโโโโโโโโโบโโโบโ yadif โโโบโ scale โโโบโโโโโโโโโโโโโโบ
โ โโโโโโโโโ โโโโโโโโโ โ
โโโโโโโโโโโโโโโโโโโโโโโโโโ
A complex filtergraph is standalone and not associated with any specific stream. It may have multiple (or zero) inputs, potentially of different types (audio or video), each of which receiving data either from a decoder or another complex filtergraph's output. It also has one or more outputs that feed either an encoder or another complex filtergraph's input.
The following example diagram represents a complex filtergraph with 3 inputs and 2 outputs (all video):
โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโ
โ complex filtergraph โ
โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโก
frames โโโโโโโโโ โโโโโโโโโโโ โโโโโโโโโโโ โโโโโโโโโโค frames
โโโโโโโโโโบโinput 0โโโบโ overlay โโโโโโโบโ overlay โโโบโoutput 0โโโโโโโโโโบ
โโโโโโโโโ โ โ โ โ โโโโโโโโโโค
frames โโโโโโโโโโญโบโ โ โญโบโ โ โ
โโโโโโโโโโบโinput 1โโฏ โโโโโโโโโโโ โ โโโโโโโโโโโ โ
โโโโโโโโโ โ โ
frames โโโโโโโโโ โโโโโโโ โโโโโโโฌโโฏ โโโโโโโโโโค frames
โโโโโโโโโโบโinput 2โโบโscaleโโบโsplitโโโโโโโโโโโโโโโโโบโoutput 1โโโโโโโโโโบ
โโโโโโโโโ โโโโโโโ โโโโโโโ โโโโโโโโโโค
โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโ
Frames from second input are overlaid over those from the first. Frames from the third input are rescaled, then duplicated into two identical streams. One of them is overlaid over the combined first two inputs, with the result exposed as the filtergraph's first output. The other duplicate ends up being the filtergraph's second output. โจ
- Encoders receive raw audio, video, or subtitle frames and encode them into encoded packets. The encoding (compression) process is typically lossy โ it degrades stream quality to make the output smaller; some encoders are lossless, but at the cost of much higher output size. A video or audio encoder receives its input from some filtergraph's output, subtitle encoders receive input from a decoder (since subtitle filtering is not supported yet). Every encoder is associated with some muxer's output elementary stream and sends its output to that muxer.
A schematic representation of an encoder looks like this:
โโโโโโโโโโโ
raw frames โ โ packets
โโโโโโโโโโโโโบโ encoder โโโโโโโโโโโบ
โ โ
โโโโโโโโโโโ
- Muxers (short for "multiplexers", yes it's a whole word, we're being fancy ๐ ) โ these babies get encoded packets for their elementary streams from encoders (that's the transcoding path) or literally straight-up from demuxers (the streamcopy path), and then they interleave them when there's more than one elementary stream, and finally they write the resulting bytes into the output file. Or a pipe. Or a network stream. Whatever you pointed them at, bestie ๐ซถ
A schematic representation of a muxer looks like this (yes the ASCII art is giving architecture-student-at-2am, I love her):
โโโโโโโโโโโโโโโโโโโโโโโโฌโโโโโโโโโโโโ
packets for stream 0 โ โ muxer โ
โโโโโโโโโโโโโโโโโโโโโโโบโ elementary stream 0 โโโโโโโโโโโโโก
โ โ โ
โโโโโโโโโโโโโโโโโโโโโโโโค global โ
packets for stream 1 โ โproperties โ
โโโโโโโโโโโโโโโโโโโโโโโบโ elementary stream 1 โ and โ
โ โ metadata โ
โโโโโโโโโโโโโโโโโโโโโโโโค โ
โ โ โ
โ ........... โ โ
โ โ โ
โโโโโโโโโโโโโโโโโโโโโโโโค โ
packets for stream N โ โ โ
โโโโโโโโโโโโโโโโโโโโโโโบโ elementary stream N โ โ
โ โ โ
โโโโโโโโโโโโโโโโโโโโโโโโดโโโโโโฌโโโโโโ
โ
write to file, network stream, โ
grabbing device, etc. โ
โ
โผ
๐ธ Streamcopy ๐ธ
okay so the simplest pipeline in ffmpeg is single-stream streamcopy โ that's copying one input elementary stream's packets, and you do not decode, filter, or encode them. Zero. Nada. The packets just vibe straight through ๐ฆ
Take an input file called INPUT.mkv with 3 elementary streams, from which we take the second one and write it to file OUTPUT.mp4. A schematic representation of such a pipeline looks like this:
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโโโโโโโ
โ demuxer โ โ unused
โโโโโโโโโโโโก elementary stream 0 โโโโโโโโโโณ
โ โ โ
โINPUT.mkv โโโโโโโโโโโโโโโโโโโโโโโค โโโโโโโโโโโโโโโโโโโโโโโโฌโโโโโโโโโโโโ
โ โ โ packets โ โ muxer โ
โ โ elementary stream 1 โโโโโโโโโโโบโ elementary stream 0 โโโโโโโโโโโโโก
โ โ โ โ โOUTPUT.mp4 โ
โ โโโโโโโโโโโโโโโโโโโโโโโค โโโโโโโโโโโโโโโโโโโโโโโโดโโโโโโโโโโโโ
โ โ โ unused
โ โ elementary stream 2 โโโโโโโโโโณ
โ โ โ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโโโโโโโ
The above pipeline can be constructed with the following commandline:
ffmpeg -i INPUT.mkv -map 0:1 -c copy OUTPUT.mp4
In this commandline (let's break it down like a group chat screenshot ๐):
- there is a single input
INPUT.mkv; - there are no input options for this input (she's low-maintenance, we stan ๐);
- there is a single output
OUTPUT.mp4; - there are two output options for this output:
-map 0:1selects the input stream to be used โ from input with index0(i.e. the first one) the stream with index1(i.e. the second one);-c copyselects thecopyencoder, i.e. streamcopy with no decoding or encoding.
Streamcopy is useful for changing the elementary stream count, container format, or modifying container-level metadata (glow-up without touching the pixels, iconic โจ). Since there is no decoding or encoding, it is very fast and there is no quality loss. However, it might not work in some cases because of a variety of factors (e.g. certain information required by the target container is not available in the source). Applying filters is obviously also impossible, since filters work on decoded frames (no frames decoded = nothing to filter, sorry babes ๐).
More complex streamcopy scenarios can be constructed โ e.g. combining streams from two input files into a single output:
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโโโโโโ โโโโโโโโโโโโโโโโโโโโโโฌโโโโโโโโโโโโ
โ demuxer 0โ โ packets โ โ muxer โ
โโโโโโโโโโโโกelementary stream 0 โโโโโโโโโโบโelementary stream 0 โโโโโโโโโโโโโก
โINPUT0.mkvโ โ โ โOUTPUT.mp4 โ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโโโโโโ โโโโโโโโโโโโโโโโโโโโโโค โ
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโโโโโโ โ โ โ
โ demuxer 1โ โ packets โelementary stream 1 โ โ
โโโโโโโโโโโโกelementary stream 0 โโโโโโโโโโบโ โ โ
โINPUT1.aacโ โ โโโโโโโโโโโโโโโโโโโโโโดโโโโโโโโโโโโ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโโโโโโ
that can be built by the commandline
ffmpeg -i INPUT0.mkv -i INPUT1.aac -map 0:0 -map 1:0 -c copy OUTPUT.mp4
The output -map option is used twice here, creating two streams in the output file โ one fed by the first input and one by the second ๐ซถ. The single instance of the -c option selects streamcopy for both of those streams. You could also use multiple instances of this option together with Stream specifiers to apply different values to each stream, as will be demonstrated in following sections (foreshadowing, love that for us ๐).
A converse scenario is splitting multiple streams from a single input into multiple outputs:
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโโโโโโโ โโโโโโโโโโโโโโโโโโโโโฌโโโโโโโโโโโโ
โ demuxer โ โ packets โ โ muxer 0 โ
โโโโโโโโโโโโก elementary stream 0 โโโโโโโโโโโบโelementary stream 0โโโโโโโโโโโโโก
โ โ โ โ โOUTPUT0.mp4โ
โINPUT.mkv โโโโโโโโโโโโโโโโโโโโโโโค โโโโโโโโโโโโโโโโโโโโโดโโโโโโโโโโโโ
โ โ โ packets โโโโโโโโโโโโโโโโโโโโโฌโโโโโโโโโโโโ
โ โ elementary stream 1 โโโโโโโโโโโบโ โ muxer 1 โ
โ โ โ โelementary stream 0โโโโโโโโโโโโโก
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโโโโโโโ โ โOUTPUT1.mp4โ
โโโโโโโโโโโโโโโโโโโโโดโโโโโโโโโโโโ
built with
ffmpeg -i INPUT.mkv -map 0:0 -c copy OUTPUT0.mp4 -map 0:1 -c copy OUTPUT1.mp4
Note how a separate instance of the -c option is needed for every output file even though their values are the same (yes even though it's literally the same value, she needs to hear it twice, it's a whole thing ๐). This is because non-global options (which is most of them) only apply in the context of the file before which they are placed.
These examples can of course be further generalized into arbitrary remappings of any number of inputs into any number of outputs go absolutely feral, bestie ๐.
๐ฅ Transcoding ๐ฅ
Transcoding is the process of decoding a stream and then encoding it again. Since encoding tends to be computationally expensive and in most cases degrades the stream quality (i.e. it is lossy), you should only transcode when you need to and perform streamcopy otherwise (it's giving "use your oven only when the microwave won't do", fr fr). Typical reasons to transcode are:
- applying filters โ e.g. resizing, deinterlacing, or overlaying video; resampling or mixing audio;
- you want to feed the stream to something that cannot decode the original codec (the codec is a hater, it simply won't โ).
โ ๏ธ Note thatffmpegwill transcode all audio, video, and subtitle streams unless you specify-c copyfor them โ she will absolutely go ahead and re-encode everything if you don't tell her otherwise, no cap ๐
Consider an example pipeline that reads an input file with one audio and one video stream, transcodes the video and copies the audio into a single output file. This can be schematically represented as follows
okay so that transcode pipeline we were just talking about? visually it's giving this, bestie:
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโโโโโโโ
โ demuxer โ โ audio packets
โโโโโโโโโโโโก stream 0 (audio) โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโฎ
โ โ โ โ
โINPUT.mkv โโโโโโโโโโโโโโโโโโโโโโโค video โโโโโโโโโโโ raw โ
โ โ โ packets โ video โ video frames โ
โ โ stream 1 (video) โโโโโโโโโโโบโ decoder โโโโโโโโโโโโโโโโฎ โ
โ โ โ โ โ โ โ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโโโโโโโ โโโโโโโโโโโ โ โ
โผ โผ
โ โ
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโโโโโโโ video โโโโโโโโโโโ โ โ
โ muxer โ โ packets โ video โ โ โ
โโโโโโโโโโโโก stream 0 (video) โโโโโโโโโโโโค encoder โโโโโโโโโโโโโโโโฏ โ
โ โ โ โ(libx264)โ โ
โOUTPUT.mp4โโโโโโโโโโโโโโโโโโโโโโโค โโโโโโโโโโโ โ
โ โ โ โ
โ โ stream 1 (audio) โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโฏ
โ โ โ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโโโโโโโ
and the commandline that makes it happen is literally:
ffmpeg -i INPUT.mkv -map 0:v -map 0:a -c:v libx264 -c:a copy OUTPUT.mp4
notice how it uses stream specifiers ":v" and ":a" to select input streams and slap different values of -c onto them ๐ซถ โ the Stream specifiers section has more deets if you need them.
โจ Filtering โจ
when you're transcoding, audio and video streams can be filtered before encoding, with either a simple or complex filtergraph. no cap.
๐ธ Simple filtergraphs ๐ธ
simple filtergraphs are the chill ones: they have exactly one input and output, both of the same type (audio or video). they're configured with the per-stream -filter option (with -vf and -af aliases for -filter:v (video) and -filter:a (audio) respectively). lowkey important: simple filtergraphs are tied to their output stream, so e.g. if you have multiple audio streams, -af will create a separate filtergraph for each one. periodt.
taking the transcoding example from above, adding filtering (and omitting audio, for clarity) makes it look like this:
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโ
โ demuxer โ โ โโโโโโโโโโโ
โโโโโโโโโโโโก video stream โ packets โ video โ frames
โINPUT.mkv โ โโโโโโโโโโโบโ decoder โโโโโโโบโโโโฎ
โ โ โ โโโโโโโโโโโ โ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโ โ
โญโโโโโโโโโโโโโโโโโโโโโโโโฏ
โ โโโโโโโโโโโโโโโโโโโโโโโโโโ
โ โ simple filtergraph โ
โ โโโโโโโโโโโโโโโโโโโโโโโโโโก
โ โ โโโโโโโโโ โโโโโโโโโ โ
โฐโโโบโโโบโ yadif โโโบโ scale โโโบโโฎ
โ โโโโโโโโโ โโโโโโโโโ โโ
โโโโโโโโโโโโโโโโโโโโโโโโโโโ
โ
โ
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโ video โโโโโโโโโโโ โ
โ muxer โ โ packets โ video โ โ
โโโโโโโโโโโโก video stream โโโโโโโโโโโโค encoder โโโโโโโโโโโโโโโโโฏ
โOUTPUT.mp4โ โ โ โ
โ โ โ โโโโโโโโโโโ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโ
๐ Complex filtergraphs ๐
complex filtergraphs are those which cannot be described as simply a linear processing chain applied to one stream. this is the case, for example, when the graph has more than one input and/or output, or when output stream type is different from input. complex filtergraphs are configured with the -filter_complex option. note that this option is global, since a complex filtergraph, by its nature, cannot be unambiguously associated with a single stream or file. each instance of -filter_complex creates a new complex filtergraph, and there can be any number of them.
a trivial example of a complex filtergraph is the "overlay" filter, which has two video inputs and one video output, containing one video overlaid on top of the other. its audio counterpart is the "amix" filter.
๐ฆ Loopback decoders ๐ฆ
while decoders are normally associated with demuxer streams, it is also possible to create "loopback" decoders that decode the output from some encoder and allow it to be fed back to complex filtergraphs. this is done with the -dec directive, which takes as a parameter the index of the output stream that should be decoded. every such directive creates a new loopback decoder, indexed with successive integers starting at zero. these indices should then be used to refer to loopback decoders in complex filtergraph link labels, as described in the documentation for -filter_complex.
decoding AVOptions can be passed to loopback decoders by placing them before -dec, analogously to input/output options. iykyk.
e.g. this example is iconic:
ffmpeg -i INPUT \
-map 0:v:0 -c:v libx264 -crf 45 -f null - \
-threads 3 -dec 0:0 \
-filter_complex '[0:v][dec:0]hstack[stack]' \
-map '[stack]' -c:v ffv1 OUTPUT
this one reads an input video and:
- (line 2) encodes it with
libx264at low quality; - (line 3) decodes this encoded stream using 3 threads;
- (line 4) places decoded video side by side with the original input video;
- (line 5) combined video is then losslessly encoded and written into
OUTPUT.
such a transcoding pipeline can be represented with the following diagram:
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโ
โ demuxer โ โ โโโโโโโโโโโ โโโโโโโโโโโ โโโโโโโโโโโโโโโโโโโโโโ
โโโโโโโโโโโโก video stream โ โ video โ โ video โ โ null muxer โ
โ INPUT โ โโโโบโ decoder โโโโฌโโโโโโโโโบโ encoder โโโฌโโบโ(discards its input)โ
โ โ โ โโโโโโโโโโโ โ โ(libx264)โ โ โโโโโโโโโโโโโโโโโโโโโโ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโ โ โโโโโโโโโโโ โ
โญโโโโโโโโโโโฏ โโโโโโโโโโโ โ
โ โloopback โ โ
โ โญโโโโโโโโโโโโโค decoder โโโโโโโโโฏ
โ โ โโโโโโโโโโโ
โ โ
โ โ
โ โ โโโโโโโโโโโโโโโโโโโโโ
โ โ โcomplex filtergraphโ
โ โ โโโโโโโโโโโโโโโโโโโโโก
โ โ โ โโโโโโโโโโโโโโโ โ
โฐโโซโโบโโโบโ hstack โโโบโโฎ
โฐโโบโโโบโ โ โโ
โ โโโโโโโโโโโโโโโ โโ
โโโโโโโโโโโโโโโโโโโโโโ
โ
โโโโโโโโโโโโฌโโโโโโโโโโโโโโโโ โโโโโโโโโโโ โ
โ muxer โ โ โ video โ โ
โโโโโโโโโโโโก video stream โโโโค encoder โโโโโโโโโโโโโโโโโโโโฏ
โ OUTPUT โ โ โ (ffv1) โ
โ โ โ โโโโโโโโโโโ
โโโโโโโโโโโโดโโโโโโโโโโโโโโโโ
๐ธ STREAM SELECTION ๐ธ
okay bestie, so ffmpeg gives you the -map option when you want manual control over which streams go into each output file. You can totally skip -map and let ffmpeg do automatic stream selection, which is described below. And the -vn / -an / -sn / -dn options are the little skip buttons for video, audio, subtitle and data streams respectively โ they work whether the streams were manually mapped or automatically selected, except for streams that are outputs of complex filtergraphs. periodt.
๐ Description ๐
The sub-sections coming up describe all the rules involved in stream selection. The examples after that show how those rules actually play out in practice. Quick disclaimer though: every effort is made to accurately reflect the behavior of the program, but FFmpeg is under continuous development and the code may have changed since the time of this writing. so yeah, vibe check the version if something looks sus.
โจ Automatic stream selection โจ
When there are no map options for a particular output file, ffmpeg inspects the output format to check which types of streams can be included in it โ aka video, audio and/or subtitles. For each acceptable stream type, ffmpeg will pick one stream, when available, from among all the inputs.
It will select that stream based upon the following criteria:
- for video, it is the stream with the highest resolution,
- for audio, it is the stream with the most channels,
- for subtitles, it is the first subtitle stream found but there's a caveat. The output format's default subtitle encoder can be either text-based or image-based, and only a subtitle stream of the same type will be chosen.
In the case where several streams of the same type rate equally, the stream with the lowest index is chosen. lowkey fair.
Data or attachment streams are not automatically selected and can only be included using -map. no cap.
๐ Manual stream selection ๐
When -map is used, only user-mapped streams are included in that output file, with one possible exception for filtergraph outputs described below.
๐ฆ Complex filtergraphs ๐ฆ
If there are any complex filtergraph output streams with unlabeled pads, they will be added to the first output file. This will lead to a fatal error if the stream type is not supported by the output format. In the absence of the map option, the inclusion of these streams leads to the automatic stream selection of their types being skipped. If map options are present, these filtergraph streams are included in addition to the mapped streams.
Complex filtergraph output streams with labeled pads must be mapped once and exactly once. not twice, not zero times. exactly once. ๐
๐ง Stream handling ๐ง
Stream handling is independent of stream selection, with an exception for subtitles described below. Stream handling is set via the -codec option addressed to streams within a specific output file. In particular, codec options are applied by ffmpeg after the stream selection process and thus do not influence the latter. If no -codec option is specified for a stream type, ffmpeg will select the default encoder registered by the output file muxer.
An exception exists for subtitles. If a subtitle encoder is specified for an output file, the first subtitle stream found of any type, text or image, will be included. ffmpeg does not validate if the specified encoder can convert the selected stream or if the converted stream is acceptable within the output format. This applies generally as well: when the user sets an encoder manually, the stream selection process cannot check if the encoded stream can be muxed into the output file. If it cannot, ffmpeg will abort and all output files will fail to be processed. so uh, maybe don't yolo that one. ๐
๐ Examples ๐
The following examples illustrate the behavior, quirks and limitations of ffmpeg's stream selection methods.
They assume the following three input files.
input file 'A.avi'
stream 0: video 640x360
stream 1: audio 2 channels
input file 'B.mp4'
stream 0: video 1920x1080
stream 1: audio 2 channels
stream 2: subtitles (text)
stream 3: audio 5.1 channels
stream 4: subtitles (text)
input file 'C.mkv'
stream 0: video 1280x720
stream 1: audio 2 channels
stream 2: subtitles (image)
๐ Example: automatic stream selection ๐
ffmpeg -i A.avi -i B.mp4 out1.mkv out2.wav -map 1:a -c:a copy out3.mov
There are three output files specified, and for the first two, no -map options are set, so ffmpeg will select streams for these two files automatically.
out1.mkv is a Matroska container file and accepts video, audio and subtitle streams, so ffmpeg will try to select one of each type. For video, it will select stream 0 from B.mp4, which has the highest resolution among all the input video streams. For audio, it will select stream 3 from B.mp4, since it has the greatest number of channels. For subtitles, it will select stream 2 from B.mp4, which is the first subtitle stream from among A.avi and B.mp4.
out2.wav accepts only audio streams, so only stream 3 from B.mp4 is selected.
For out3.mov, since a -map option is set, no automatic stream selection will occur. The -map 1:a option will select all audio streams from the second input B.mp4. No other streams will be included in this output file.
For the first two outputs, all included streams will be transcoded. The encoders chosen will be the default ones registered by each output format, which may not match the codec of the selected input streams. ngl that's the classic default-encoder surprise.
For the third output, codec option for audio streams has been set to copy, so no decoding-filtering-encoding operations will occur, or can occur. Packets of selected streams shall be conveyed from the input file and muxed within the output file. slay, zero re-encode.
๐ Example: automatic subtitles selection ๐
ffmpeg -i C.mkv out1.mkv -c:s dvdsub -an out2.mkv
Although out1.mkv is a Matroska container file which accepts subtitle streams, only a video and audio stream shall be selected. The subtitle stream of C.mkv is image-based and the default subtitle encoder of the Matroska muxer is text-based, so a transcode operation for the subtitles is expected to fail and hence the stream isn't selected. However, in out2.mkv, a subtitle encoder is specified in the command and so, the subtitle stream is selected, in addition to the video stream. The presence of -an disables audio stream selection for out2.mkv. iconic behavior, honestly.
๐ฅ Example: unlabeled filtergraph outputs ๐ฅ
ffmpeg -i A.avi -i C.mkv -i B.mp4 -filter_complex "overlay" out1.mp4 out2.srt
A filtergraph is setup here using the -filter_complex option and consists of a single video filter. The overlay filter requires exactly two video inputs, but none are specified, so the first two available video streams are used, those of A.avi and C.mkv. The output pad of the filter has no label and so is sent to the first output file out1.mp4. Due to this, automatic selection of the video stream is skipped, which would have selected the stream in B.mp4. The audio stream with most channels viz. stream 3 in B.mp4, is chosen automatically. No subtitle stream is chosen however, since the MP4 format has no default subtitle encoder registered, and the user hasn't specified a subtitle encoder.
The 2nd output file, out2.srt, only accepts text-based subtitle streams. So, even though the first subtitle stream available belongs to C.mkv, it is image-based and hence skipped. The selected stream, stream 2 in B.mp4, is the first text-based subtitle stream. iykyk, image subs said not today.
๐ Example: labeled filtergraph outputs ๐
ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0[outv];overlay;aresample" \
-map '[outv]' -an out1.mp4 \
out2.mkv \
-map '[outv]' -map 1:a:0 out3.mkv
The above command will fail, as the output pad labelled [outv] has been mapped twice. None of the output files shall be processed. not me accidentally mapping the same pad twice ๐ญ
ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0[outv];overlay;aresample" \
-an out1.mp4 \
out2.mkv \
-map 1:a:0 out3.mkv
This command above will also fail as the hue filter output has a label, [outv], and hasn't been mapped anywhere. the way that orphaned label just sits there ๐
The command should be modified as follows,
ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0,split=2[outv1][outv2];overlay;aresample" \
-map '[outv1]' -an out1.mp4 \
out2.mkv \
-map '[outv2]' -map 1:a:0 out3.mkv
The video stream from B.mp4 is sent to the hue filter, whose output is cloned once using the split filter, and both outputs labelled. Then a copy each is mapped to the first and third output files. bestie said "one label per pad," and we listened.
The overlay filter, requiring two video inputs, uses the first two unused video streams. Those are the streams from A.avi and C.mkv. The overlay output isn't labelled, so it is sent to the first output file out1.mp4, regardless of the presence of the -map option.
The aresample filter is sent the first unused audio stream, that of A.avi. Since this filter output is also unlabelled, it too is mapped to the first output file. The presence of -an only suppresses automatic or manual stream selection of audio streams, not outputs sent from filtergraphs. Both these mapped streams shall be ordered before the mapped stream in out1.mp4. lowkey a plot twist, but make sense.
The video, audio and subtitle streams mapped to out2.mkv are entirely determined by automatic stream selection.
out3.mkv consists of the cloned video output from the hue filter and the first audio stream from B.mp4. absolutely ate.
โจ OPTIONS โจ
All the numerical options, if not specified otherwise, accept a string representing a number as input, which may be followed by one of the SI unit prefixes, for example: 'K', 'M', or 'G'.
If 'i' is appended to the SI unit prefix, the complete prefix will be interpreted as a unit prefix for binary multiples, which are based on powers of 1024 instead of powers of 1000. Appending 'B' to the SI unit prefix multiplies the value by 8. This allows using, for example: 'KB', 'MiB', 'G' and 'B' as number suffixes. cute little number math, fr fr.
Options which do not take arguments are boolean options, and set the corresponding value to true. They can be set to false by prefixing the option name with "no". For example using -nofoo will set the boolean option with name "foo" to false. so -nofoo is literally the "un-yeah" button.
Options that take arguments support a special syntax where the argument given on the command line is interpreted as a path to the file from which the actual argument value is loaded. To use this feature, add a forward slash '/' immediately before the option name (after the leading dash). E.g.
ffmpeg -i INPUT -/filter:v filter.script OUTPUT
โฆit pulls in a whole filtergraph description from the file called filter.script. Like, that file is the main character now. ๐ฌ
๐ Stream specifiers ๐
Okay so some options are per-stream โ think bitrate, think codec โ and stream specifiers are the little gadget that tells ffmpeg exactly which stream(s) an option belongs to. No more "it applied to the wrong one" heartbreak, iykyk. ๐
A stream specifier is a string, and you generally stick it onto the end of the option name, separated by a colon. So for example -codec:a:1 ac3 has the stream specifier a:1 in it, which matches the second audio stream. Which means it would pick the ac3 codec for that second audio stream. Slay. โจ
Specifier can match several streams too, and then the option just gets applied to all of them. E.g. the stream specifier in -b:a 128k matches every audio stream.
An empty stream specifier matches all streams. Like, -codec copy or -codec: copy would copy all the streams with zero reencoding. Obsessed. ๐ซถ
Possible forms of stream specifiers are:
stream_indexโ Matches the stream with this index. E.g.-threads:1 4would set the thread count for the second stream to 4. And ifstream_indexis used as an additional stream specifier (see below), then it selects stream numberstream_indexfrom the matching streams. Stream numbering is based on the order of the streams as detected by libavformat โ except when a stream group specifier or program ID is also specified, in which case it's based on the ordering of the streams in the group or program. Little detail, big consequences. ๐stream_type[:additional_stream_specifier]โstream_typeis one of these:vorVfor video,afor audio,sfor subtitle,dfor data, andtfor attachments.vmatches all video streams, whileVonly matches video streams that are not attached pictures, video thumbnails or cover arts. (Yes bestie, that distinction is the whole point. ๐ผ๏ธ) Ifadditional_stream_specifieris used, then it matches streams that both have this type and match the additional specifier. Otherwise it matches all streams of the specified type.g:group_specifier[:additional_stream_specifier]โ Matches streams that are in the group with the specifiergroup_specifier. Ifadditional_stream_specifieris used, then it matches streams that both are part of the group and match theadditional_stream_specifier.group_specifiermay be one of the following:group_indexโ Match the stream with this group index.#group_idori:group_idโ Match the stream with this group id.
p:program_id[:additional_stream_specifier]โ Matches streams that are in the program with the idprogram_id. Ifadditional_stream_specifieris used, then it matches streams that both are part of the program and match theadditional_stream_specifier.#stream_idori:stream_idโ Match the stream by stream id (e.g. PID in MPEG-TS container).m:key[:value]โ Matches streams with the metadata tagkeyhaving the specifiedvalue. Ifvalueis not given, it matches streams that contain the given tag with any value. Heads up: the colon character:inkeyorvalueneeds to be backslash-escaped. ๐disp:dispositions[:additional_stream_specifier]โ Matches streams with the given disposition(s).dispositionsis a list of one or more dispositions (as printed by the-dispositionsoption) joined with+.uโ Matches streams with usable configuration: the codec must be defined, and the essential info such as video dimension or audio sample rate must be present. Basically "is it actually usable?" vibes. โ
Note that in ffmpeg, matching by metadata will only work properly for input files. Fr fr, don't come for me, that's just how it is. ๐ญ
โจ Generic options โจ
These options are shared amongst the ff* tools. Group project energy, but like, the good kind. ๐ง
-L,-licenseโ Show license. Read it, bestie. ๐-h,-?,-help,--help [arg]โ Show help. You can drop an optional parameter to print help about one specific thing. If you give no argument at all, only the basic (non advanced) tool options are shown. The possible values ofargare:longโ Print advanced tool options in addition to the basic tool options.fullโ Print the complete list of options, including shared and private options for encoders, decoders, demuxers, muxers, filters, etc.decoder=decoder_nameโ Print detailed information about the decoder nameddecoder_name. Use the-decodersoption to get a list of all decoders.encoder=encoder_nameโ Print detailed information about the encoder namedencoder_name. Use the-encodersoption to get a list of all encoders.demuxer=demuxer_nameโ Print detailed information about the demuxer nameddemuxer_name. Use the-formatsoption to get a list of all demuxers and muxers.muxer=muxer_nameโ Print detailed information about the muxer namedmuxer_name. Use the-formatsoption to get a list of all muxers and demuxers.filter=filter_nameโ Print detailed information about the filter namedfilter_name. Use the-filtersoption to get a list of all filters.bsf=bitstream_filter_nameโ Print detailed information about the bitstream filter namedbitstream_filter_name. Use the-bsfsoption to get a list of all bitstream filters.protocol=protocol_nameโ Print detailed information about the protocol namedprotocol_name. Use the-protocolsoption to get a list of all protocols.
-versionโ Show version. ๐ท๏ธ-buildconfโ Show the build configuration, one option per line.-formatsโ Show available formats (including devices).-demuxersโ Show available demuxers.-muxersโ Show available muxers.-devicesโ Show available devices.-codecsโ Show all codecs known to libavcodec.
Note that the term 'codec' is used throughout this documentation as a shortcut for what is more correctly called a media bitstream format. So like, technically correct is the best kind of correct, but we're all saying codec. ๐
-decodersโ Show available decoders.-encodersโ Show all available encoders.-bsfsโ Show available bitstream filters.-protocolsโ Show available protocols.-filtersโ Show available libavfilter filters.-pix_fmtsโ Show available pixel formats.-sample_fmtsโ Show available sample formats.-layoutsโ Show channel names and standard channel layouts. ๐-dispositionsโ Show stream dispositions.-colorsโ Show recognized color names. ๐-sourcesdevice[,opt1=val1[,opt2=val2]...] โ Show autodetected sources of the input device. Some devices may provide system-dependent source names that cannot be autodetected, so the returned list cannot be assumed to be always complete. Ngl, it's giving "best effort". ๐
ffmpeg -sources pulse,server=192.168.0.4
-sinksdevice[,opt1=val1[,opt2=val2]...] โ Show autodetected sinks of the output device. Some devices may provide system-dependent sink names that cannot be autodetected. Same deal: the returned list cannot be assumed to be always complete.
ffmpeg -sinks pulse,server=192.168.0.4
-loglevel [flags+]loglevel|-v [flags+]loglevelโ Set the logging level and flags used by the library. This is the volume knob for โจdramaโจ in your terminal.
The optional flags prefix can consist of the following values:
repeatโ Indicates that repeated log output should not be compressed to the first line, and the "Last message repeated n times" line will be omitted.levelโ Indicates that log output should add a[level]prefix to each message line. This can be used as an alternative to log coloring, e.g. when dumping the log to file.timeโ Indicates that log lines should be prefixed with time information.datetimeโ Indicates that log lines should be prefixed with date and time information.
Flags can also be used alone by adding a +/- prefix to set/reset a single flag, without affecting other flags or changing the loglevel. And when you're setting both flags and loglevel, a + separator is expected between the last flags value and before the loglevel. Tiny syntax, huge consequences. ๐
loglevel is a string or a number containing one of the following values:
quiet,-8โ Show nothing at all; be silent. ๐คซpanic,0โ Only show fatal errors which could lead the process to crash, such as an assertion failure. This is not currently used for anything.fatal,8โ Only show fatal errors. These are errors after which the process absolutely cannot continue.error,16โ Show all errors, including ones which can be recovered from.warning,24โ Show all warnings and errors. Any message related to possibly incorrect or unexpected events will be shown.info,32โ Show informative messages during processing. This is in addition to warnings and errors. This is the default value.verbose,40โ Same asinfo, except more verbose.debug,48โ Show everything, including debugging information. ๐trace,56
For example, to enable repeated log output, add the level prefix, and set loglevel to verbose:
ffmpeg -loglevel repeat+level+verbose -i input output
Another example that enables repeated log output without affecting the current state of the level prefix flag or loglevel:
ffmpeg [...] -loglevel +repeat
By default the program logs to stderr. If coloring is supported by the terminal, colors are used to mark errors and warnings. Log coloring can be disabled by setting the environment variable AV_LOG_FORCE_NOCOLOR, or can be forced by setting the environment variable AV_LOG_FORCE_COLOR. ๐จ
-reportโ Dump the full command line and log output to a file namedprogram-YYYYMMDD-HHMMSS.login the current directory. This file can be useful for bug reports โ genuinely, maintainers love this. It also implies-loglevel debug.
Setting the environment variable FFREPORT to any value has the same effect. If the value is a :-separated key=value sequence, these options will affect the report; option values must be escaped if they contain special characters or the options delimiter : (see the "Quoting and escaping" section in the ffmpeg-utils manual).
The following options are recognized:
fileโ set the file name to use for the report;%pis expanded to the name of the program,%tis expanded to a timestamp,%%is expanded to a plain%levelโ set the log verbosity level using a numerical value (see-loglevel).
For example, to output a report to a file named ffreport.log using a log level of 32 (alias for log level info):
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
Like, if you mess up parsing the environment variable it's not fatal, bestie โ it just won't show up in the report. Casual. ๐
-hide_bannerโ suppresses the banner. Okay so normally every FFmpeg tool flexes on you with a copyright notice, the build options, and library versions โ this option is the "not now, main character" button that shuts all that up. ๐-cpuflags flags(global) โ lets you set and clear cpu flags. โ ๏ธ This one is for testing only โ do not touch it unless you genuinely know what you're doing, no cap.
ffmpeg -cpuflags -sse+mmx ...
ffmpeg -cpuflags mmx ...
ffmpeg -cpuflags 0 ...
The possible flags for this option are: โจ
- x86
mmxmmxextssesse2sse2slowsse3sse3slowssse3atomsse4.1sse4.2avxavx2xopfma3fma43dnow3dnowextbmi1bmi2cmov
- ARM
armv5tearmv6armv6t2vfpvfpv3neonsetend
- AArch64
armv8vfpneon
- PowerPC
altivec
- Specific Processors
pentium2pentium3pentium4k6k62athlonathlonxpk8
-cpucount count(global) โ overrides the detection of CPU count. Same energy as above: testing only, don't use it unless you know what you're doing, fr fr. ๐
ffmpeg -cpucount 2
-max_alloc bytesโ sets the max size limit for allocating a block on the heap, which ffmpeg's little family ofmallocfunctions does. ๐ซถ Exercise extreme caution with this one. Like, genuinely don't use it if you don't understand the full consequence of doing so. Default isINT_MAX.
๐ฆ AVOptions ๐ฆ
These options are handed to you directly by the libavformat, libavdevice and libavcodec libraries. Wanna see the whole list of available AVOptions? Just hit -help. They split into two categories:
generic
These can be set for any container, codec or device. Generic options live under AVFormatContext options for containers/devices, and under AVCodecContext options for codecs. ๐
private
These are specific to the given container, device or codec, and they're listed under their corresponding containers/devices/codecs.
So, for example, if you wanna write an ID3v2.3 header instead of the default ID3v2.4 into an MP3 file, you use the id3v2_version private option of the MP3 muxer:
ffmpeg -i input.flac -id3v2_version 3 out.mp3
And listen โ all codec AVOptions are per-stream, which means you gotta attach a stream specifier to them:
ffmpeg -i multichannel.mxf -map 0:v:0 -map 0:a:0 -map 0:a:0 -c:a:0 ac3 -b:a:0 640k -ac:a:1 2 -c:a:1 aac -b:2 128k out.mp4
In that example, a multichannel audio stream gets mapped twice for the output. ๐ The first instance is encoded with codec ac3 at bitrate 640k. The second instance is downmixed to 2 channels and encoded with codec aac, and a bitrate of 128k is specified for it using the absolute index of the output stream.
Note: the-nooptionsyntax cannot be used for boolean AVOptions โ use-option 0/-option 1instead. ๐
Note: the old undocumented way of specifying per-stream AVOptions by prependingv/a/sto the option name is obsolete now and will be removed soon. RIP to a real one. ๐
๐ Main options ๐
-f fmt(input/output) โ forces the input or output file format. Normally the format is auto-detected for input files and guessed from the file extension for output files, so bestie, you won't need this in most cases. โจ-i url(input) โ the input file url. That's it, that's the whole thing. ๐-y(global) โ overwrites output files without asking. No permission slip needed. ๐-n(global) โ the opposite vibe: do not overwrite output files, and bounce immediately if a specified output file already exists. ๐ช-stream_loop number(input) โ sets how many times the input stream shall be looped. Loop0means no loop, loop-1means infinite loop. ๐-recast_media(global) โ allows forcing a decoder of a different media type than the one detected or designated by the demuxer. Super useful for decoding media data that's been muxed as data streams. ๐ง-c[:stream_specifier] codec(input/output,per-stream)-codec[:stream_specifier] codec(input/output,per-stream) โ selects an encoder (when you use it before an output file) or a decoder (when you use it before an input file) for one or more streams.codecis the name of a decoder/encoder, or the special value"copy"(output only) which says "this stream is not getting re-encoded, thank you". ๐
For example:
ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
encodes all video streams with libx264 and copies all audio streams.
For each stream, the last matching "c" option is the one that gets applied, so:
ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
will copy all the streams except the second video (encoded with libx264) and the 138th audio (encoded with libvorbis). So specific. Obsessed. ๐ฏ
-t duration(input/output) โ when it's an input option (before-i), it limits how much data gets read from the input file. When it's an output option (before an output url), it stops writing the output once its duration reaches duration. โณ
duration has to be a time duration specification โ check the Time duration section in the ffmpeg-utils(1) manual.
-to and -t are mutually exclusive, and -t wins the fight.
-to position(input/output) โ stops writing the output, or reading the input, at position. position must be a time duration specification โ see the Time duration section in theffmpeg-utils(1)manual. ๐
-to and -t are mutually exclusive, and -t has priority.
-fs limit_size(output) โ sets the file size limit, expressed in bytes. After the limit is exceeded, no further chunk of bytes gets written. Heads up: the size of the output file ends up slightly more than the requested file size. ๐-ss position(input/output) โ when used as an input option (before-i), it seeks in this input file to position. Real talk though: in most formats it's literally not possible to seek exactly, so ffmpeg seeks to the closest seek point before position. When transcoding and-accurate_seekis enabled (which is the default), that extra segment between the seek point and position gets decoded and discarded. When you're doing stream copy, or when-noaccurate_seekis used, it gets preserved instead. ๐ฆ
When used as an output option (before an output url), it decodes but discards input until the timestamps reach position.
position must be a time duration specification โ see the Time duration section in the ffmpeg-utils(1) manual.
-sseof position(input) โ same as-ssbut relative to the "end of file". So negative values are earlier in the file, and0is at EOF. ๐ธ-isync input_index(input) โ assigns an input as a sync source. โญ
This takes the difference between the start times of the target and the reference inputs, then offsets the timestamps of the target file by that difference. For results you actually expect, the source timestamps of the two inputs should derive from the same clock source. If copyts is set, then start_at_zero must also be set. And if either of the inputs has no starting timestamp, no sync adjustment is made at all.
Acceptable values are those that refer to a valid ffmpeg input index. If the sync reference is the target index itself, or -1, then no adjustment is made to the target timestamps. Also a sync reference may not itself be synced to any other input. ๐
Default value is -1.
-itsoffset offset(input) โ sets the input time offset. โฐ
offset must be a time duration specification โ see the Time duration section in the ffmpeg-utils(1) manual.
The offset gets added to the timestamps of the input files. Specifying a positive offset means the corresponding streams are delayed by the time duration specified in offset.
-itsscale scale(input,per-stream) โ rescales input timestamps. scale should be a floating point number. ๐ข-timestamp date(output) โ sets the recording timestamp in the container.
date must be a date specification โ see the Date section in the ffmpeg-utils(1) manual.
-metadata[:metadata_specifier] key=value(output,per-metadata) โ sets a metadata key/value pair. ๐ท๏ธ
You can optionally give a metadata_specifier to set metadata on streams, chapters or programs โ see the -map_metadata documentation for the deets.
This option overrides metadata set with -map_metadata. And yes, you can delete metadata too, just by using an empty value. โจ
For example, setting the title in the output file:
ffmpeg -i in.avi -metadata title="my title" out.flv
To set the language of the first audio stream:
ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT
-disposition[:stream_specifier] value(output,per-stream) โ sets the disposition flags for a stream. ๐
Default value: by default, all disposition flags are copied from the input stream โ unless the output stream this option applies to is fed by a complex filtergraph, in which case no disposition flags are set by default.
value is a sequence of disposition flags separated by + or -. A + prefix adds the given disposition, - removes it. If the first flag is also prefixed with + or -, the resulting disposition is the default value updated by value. If the first flag is not prefixed, the resulting disposition is just value. And yeah, you can clear the disposition entirely by setting it to 0. ๐
If no -disposition options were specified for an output file, ffmpeg will automatically set the 'default' disposition flag on the first stream of each type โ but only when there are multiple streams of that type in the output file and no stream of that type is already marked as default. So helpful. ๐ซถ
The -dispositions option lists the known disposition flags.
For example, to make the second audio stream the default stream:
ffmpeg -i in.mkv -c copy -disposition:a:1 default out.mkv
To make the second subtitle stream the default stream and remove the default disposition from the first subtitle stream:
ffmpeg -i in.mkv -c copy -disposition:s:0 0 -disposition:s:1 default out.mkv
To add an embedded cover/thumbnail:
ffmpeg -i in.mp4 -i IMAGE -map 0 -map 1 -c copy -c:v:1 png -disposition:v:1 attached_pic out.mp4
More -disposition recipes, because the first audio stream deserves main character energy:
To add the original flag and remove the comment flag from the first audio stream, while leaving its other disposition flags alone:
ffmpeg -i in.mkv -c copy -disposition:a:0 +original-comment out.mkv
To remove original and add comment to the first audio stream, without touching its other disposition flags:
ffmpeg -i in.mkv -c copy -disposition:a:0 -original+comment out.mkv
To set only original and comment on the first audio stream, and remove its other disposition flags:
ffmpeg -i in.mkv -c copy -disposition:a:0 original+comment out.mkv
To remove all disposition flags from the first audio stream:
ffmpeg -i in.mkv -c copy -disposition:a:0 0 out.mkv
Heads up, bestie: not all muxers support embedded thumbnails, and the ones that do only support a few formats, like JPEG or PNG.
-programโ syntax:[title=title:][program_num=program_num:]st=stream[:st=stream...](output). Creates a program with the specifiedtitle,program_num, and adds the specified stream(s) to it.-stream_groupโ syntax:[map=input_file_id=stream_group][type=type:]st=stream[:st=stream][:stg=stream_group][:id=stream_group_id...](output). Creates a stream group of the specifiedtypeandstream_group_id, or maps an input group, adding the specified stream(s) and/or previously definedstream_group(s) to it.
type can be one of these:
iamf_audio_elementโ groups streams that belong to the same IAMF Audio Element.
For this group type, these options are available:
audio_element_typeโ the Audio Element type. Supported values:channelโ scalable channel audio representationsceneโ Ambisonics representation
demixingโ demixing information used to reconstruct a scalable channel audio representation. This option must be separated from the rest with a,, and it takes thesekey=valueoptions:parameter_idโ an identifier parameters blocks in frames may refer todmixp_modeโ a pre-defined combination of demixing parameters
recon_gainโ recon gain information used to reconstruct a scalable channel audio representation. This option must be separated from the rest with a,, and it takes thesekey=valueoptions:parameter_idโ an identifier parameters blocks in frames may refer to
layerโ a layer defining a Channel Layout in the Audio Element. This option must be separated from the rest with a,. Several,-separated entries can be defined, and at least one must be set. It takes these:-separatedkey=valueoptions:ch_layoutโ the layer's channel layoutflagsโ available flags:recon_gainโ whether to signal ifrecon_gainis present as metadata in parameter blocks within frames
output_gainoutput_gain_flagsโ which channelsoutput_gainapplies to. Available flags:FLFRBLBRTFLTFR
ambisonics_modeโ the ambisonics mode. This has no effect ifaudio_element_typeis set tochannel. Supported values:monoโ each ambisonics channel is coded as an individual mono stream in the group
default_wโ default weight value
iamf_mix_presentationโ groups streams that belong to all IAMF Audio Element the same IAMF Mix Presentation references.
For this group type, these options are available:
submixโ a sub-mix within the Mix Presentation. This option must be separated from the rest with a,. Several,-separated entries can be defined, and at least one must be set. It takes these:-separatedkey=valueoptions:parameter_idโ an identifier parameters blocks in frames may refer to, for post-processing the mixed audio signal to generate the audio signal for playbackparameter_rateโ the sample rate duration fields in parameters blocks in frames that refer to thisparameter_idare expressed asdefault_mix_gainโ default mix gain value to apply when there are no parameter blocks sharing the sameparameter_idfor a given frameelementโ references an Audio Element used in this Mix Presentation to generate the final output audio signal for playback. This option must be separated from the rest with a|. Several|-separated entries can be defined, and at least one must be set. It takes these:-separatedkey=valueoptions:stgโ thestream_group_idfor an Audio Element which this sub-mix refers toparameter_idโ an identifier parameters blocks in frames may refer to, for applying any processing to the referenced and rendered Audio Element before being summed with other processed Audio Elementsparameter_rateโ the sample rate duration fields in parameters blocks in frames that refer to thisparameter_idare expressed asdefault_mix_gainโ default mix gain value to apply when there are no parameter blocks sharing the sameparameter_idfor a given frameannotationsโ akey=valuestring describing the sub-mix element, wherekeyis a string conforming to BCP-47 that specifies the language for thevaluestring.keymust be the same as the one in the mix's annotations.headphones_rendering_modeโ indicates whether the input channel-based Audio Element is rendered to stereo loudspeakers or spatialized with a binaural renderer when played back on headphones. This has no effect if the referenced Audio Element'saudio_element_typeis set tochannel. Supported values:stereobinaural
layoutโ specifies the layouts for this sub-mix on which the loudness information was measured. This option must be separated from the rest with a|. Several|-separated entries can be defined, and at least one must be set. It takes these:-separatedkey=valueoptions:layout_typeloudspeakersโ the layout follows the loudspeaker sound system convention of ITU-2051-3binauralโ the layout is binaural
sound_systemโ channel layout matching one of Sound Systems A to J of ITU-2051-3, plus 7.1.2 and 3.1.2. This has no effect iflayout_typeis set tobinaural.integrated_loudnessโ the program integrated loudness information, as defined in ITU-1770-4digital_peakโ the digital (sampled) peak value of the audio signal, as defined in ITU-1770-4true_peakโ the true peak of the audio signal, as defined in ITU-1770-4dialog_anchored_loudnessโ the Dialogue loudness information, as defined in ITU-1770-4album_anchored_loudnessโ the Album loudness information, as defined in ITU-1770-4
annotationsโ akey=valuestring describing the mix, wherekeyis a string conforming to BCP-47 that specifies the language for thevaluestring.keymust be the same as the ones in all sub-mix element's annotationss.
E.g. to create an scalable 5.1 IAMF file from several WAV input files:
ffmpeg -i front.wav -i back.wav -i center.wav -i lfe.wav
-map 0:0 -map 1:0 -map 2:0 -map 3:0 -c:a opus
-stream_group type=iamf_audio_element:id=1:st=0:st=1:st=2:st=3,
demixing=parameter_id=998,
recon_gain=parameter_id=101,
layer=ch_layout=stereo,
layer=ch_layout=5.1(side),
-stream_group type=iamf_mix_presentation:id=2:stg=0:annotations=en-us=Mix_Presentation,
submix=parameter_id=100:parameter_rate=48000|element=stg=0:parameter_id=100:annotations=en-us=Scalable_Submix|layout=sound_system=stereo|layout=sound_system=5.1(side)
-streamid 0:0 -streamid 1:1 -streamid 2:2 -streamid 3:3 output.iamf
To copy the two stream groups (Audio Element and Mix Presentation) from an input IAMF file with four streams into an mp4 output:
ffmpeg -i input.iamf -c:a copy -stream_group map=0=0:st=0:st=1:st=2:st=3 -stream_group map=0=1:stg=0
-streamid 0:0 -streamid 1:1 -streamid 2:2 -streamid 3:3 output.mp4
-target type(output)โ specify target file type (vcd,svcd,dvd,dv,dv50).typemay be prefixed withpal-,ntsc-, orfilm-to use the corresponding standard. All the format options (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
Nevertheless you can specify additional options as long as you know they do not conflict with the standard, as in:
๐ target presets: one flag, whole aesthetic
okay so the -target preset vibe in action is literally this:
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
The parameters set for each target are as follows, bestie:
VCD
<pal>:
-f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
-s 352x288 -r 25
-codec:v mpeg1video -g 15 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
-ar 44100 -ac 2
-codec:a mp2 -b:a 224k
<ntsc>:
-f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
-s 352x240 -r 30000/1001
-codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
-ar 44100 -ac 2
-codec:a mp2 -b:a 224k
<film>:
-f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324
-s 352x240 -r 24000/1001
-codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680
-ar 44100 -ac 2
-codec:a mp2 -b:a 224k
SVCD
<pal>:
-f svcd -packetsize 2324
-s 480x576 -pix_fmt yuv420p -r 25
-codec:v mpeg2video -g 15 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1
-ar 44100
-codec:a mp2 -b:a 224k
<ntsc>:
-f svcd -packetsize 2324
-s 480x480 -pix_fmt yuv420p -r 30000/1001
-codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1
-ar 44100
-codec:a mp2 -b:a 224k
<film>:
-f svcd -packetsize 2324
-s 480x480 -pix_fmt yuv420p -r 24000/1001
-codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1
-ar 44100
-codec:a mp2 -b:a 224k
DVD
<pal>:
-f dvd -muxrate 10080k -packetsize 2048
-s 720x576 -pix_fmt yuv420p -r 25
-codec:v mpeg2video -g 15 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008
-ar 48000
-codec:a ac3 -b:a 448k
<ntsc>:
-f dvd -muxrate 10080k -packetsize 2048
-s 720x480 -pix_fmt yuv420p -r 30000/1001
-codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008
-ar 48000
-codec:a ac3 -b:a 448k
<film>:
-f dvd -muxrate 10080k -packetsize 2048
-s 720x480 -pix_fmt yuv420p -r 24000/1001
-codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008
-ar 48000
-codec:a ac3 -b:a 448k
DV
<pal>:
-f dv
-s 720x576 -pix_fmt yuv420p -r 25
-ar 48000 -ac 2
<ntsc>:
-f dv
-s 720x480 -pix_fmt yuv411p -r 30000/1001
-ar 48000 -ac 2
<film>:
-f dv
-s 720x480 -pix_fmt yuv411p -r 24000/1001
-ar 48000 -ac 2
The dv50 target is identical to the dv target except that the pixel format set is yuv422p for all three standards.
๐จ Any user-set value for a parameter above will override the target preset value. In that case, the output may not comply with the target standard.
-dn(input/output) โ As an input option, blocks all data streams of a file from being filtered or being automatically selected or mapped for any output. See-discardoption to disable streams individually. As an output option, disables data recording i.e. automatic selection or mapping of any data stream. For full manual control see the-mapoption.-dframesnumber (output) โ Set the number of data frames to output. This is an obsolete alias for-frames:d, which you should use instead.-frames[:stream_specifier]framecount (output,per-stream) โ Stop writing to the stream after framecount frames.-q[:stream_specifier]q (output,per-stream),-qscale[:stream_specifier]q (output,per-stream) โ Use fixed quality scale (VBR). The meaning of q/qscale is codec-dependent. If qscale is used without a stream_specifier then it applies only to the video stream, this is to maintain compatibility with previous behavior and as specifying the same codec specific value to 2 different codecs that is audio and video generally is not what is intended when no stream_specifier is used.-filter[:stream_specifier]filtergraph (output,per-stream) โ Create the filtergraph specified by filtergraph and use it to filter the stream. filtergraph is a description of the filtergraph to apply to the stream, and must have a single input and a single output of the same type of the stream. In the filtergraph, the input is associated to the labelin, and the output to the labelout. See theffmpeg-filtersmanual for more information about the filtergraph syntax. See the-filter_complexoption if you want to create filtergraphs with multiple inputs and/or outputs.-reinit_filter[:stream_specifier]integer (input,per-stream) โ This boolean option determines if the filtergraph(s) to which this stream is fed gets reinitialized when input frame parameters change mid-stream. This option is enabled by default as most video and all audio filters cannot handle deviation in input frame properties. Upon reinitialization, existing filter state is lost, like e.g. the frame countnreference available in some filters. Any frames buffered at time of reinitialization are lost. The properties where a change triggers reinitialization are, for video, frame resolution or pixel format; for audio, sample format, sample rate, channel count or channel layout.-drop_changed[:stream_specifier]integer (input,per-stream) โ This boolean option determines whether a frame with differing frame parameters mid-stream gets dropped instead of leading to filtergraph reinitialization, as that would lead to loss of filter state. Generally useful to avoid corrupted yet decodable packets in live streaming inputs. Default is false.-filter_threadsnb_threads (global) โ Defines how many threads are used to process a filter pipeline. Each pipeline will produce a thread pool with this many threads available for parallel processing. The default is the number of available CPUs.-filter_buffered_framesnb_frames (global) โ Defines the maximum number of buffered frames allowed in a filtergraph. Under normal circumstances, a filtergraph should not buffer more than a few frames, especially if frames are being fed to it and read from it in a balanced way (which is the intended behavior in ffmpeg). That said, this option allows you to limit the total number of frames buffered across all links in a filtergraph. If more frames are generated, filtering is aborted and an error is returned. The default value is0, which means no limit.-pre[:stream_specifier]preset_name (output,per-stream) โ Specify the preset for matching stream(s).-stats(global) โ Log encoding progress/statistics as"info"-level log (see-loglevel). It is on by default, to explicitly disable it you need to specify-nostats.-stats_periodtime (global) โ Set period at which encoding progress/statistics are updated. Default is0.5seconds.-print_graphs(global) โ Prints execution graph details tostderrin the format set via-print_graphs_format.-print_graphs_filefilename (global) โ Writes execution graph details to the specified file in the format set via-print_graphs_format.-print_graphs_formatformat (global) โ Sets the output format (available formats are:default,compact,csv,flat,ini,json,xml,mermaid,mermaidhtml). The default format isjson.-progressurl (global) โ Send program-friendly progress information to url. Progress information is written periodically and at the end of the encoding process. It is made ofkey=valuelines. key consists of only alphanumeric characters. The last key of a sequence of progress information is alwaysprogresswith the valuecontinueorend. The update period is set using-stats_period. For example, log progress information to stdout:
ffmpeg -progress pipe:1 -i in.mkv out.mkv
-stdinโ Enable interaction on standard input. On by default unless standard input is used as an input. To explicitly disable interaction you need to specify-nostdin. Disabling interaction on standard input is useful, for example, if ffmpeg is in the background process group. Roughly the same result can be achieved withffmpeg ... < /dev/nullbut it requires a shell.-debug_ts(global) โ Print timestamp/latency information. It is off by default. This option is mostly useful for testing and debugging purposes, and the output format may change from one version to another, so it should not be employed by portable scripts. See also the option-fdebug ts.-attachfilename (output) โ Add an attachment to the output file. This is supported by a few formats like Matroska for e.g. fonts used in rendering subtitles. Attachments are implemented as a specific type of stream, so this option will add a new stream to the file. It is then possible to use per-stream options on this stream in the usual way. Attachment streams created with this option will be created after all the other streams (i.e. those created with-mapor automatic mappings). Note that for Matroska you also have to set the mimetype metadata tag:
ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
(assuming that the attachment stream will be third in the output file).
-dump_attachment[:stream_specifier]filename (input,per-stream) โ Extract the matching attachment stream into a file named filename. If filename is empty, then the value of the"filename"metadata tag will be used. E.g. to extract the first attachment to a file named 'out.ttf':
ffmpeg -dump_attachment:t:0 out.ttf -i INPUT
To extract all attachments to files determined by the "filename" tag:
ffmpeg -dump_attachment:t "" -i INPUT
๐ธ technical note, bestie โ attachments are literally implemented as codec extradata, so this option can actually be used to pull extradata out of any stream, not just attachments. iykyk ๐
โจ Video Options โจ
-vframesnumber (output) โ sets the number of video frames to output. ngl this one's an obsolete alias for-frames:v, so use that instead, okay? ๐-r[:stream_specifier]fps (input/output,per-stream) โ sets the frame rate (Hz value, fraction or abbreviation).
as an input option, it ignores any timestamps stored in the file and generates timestamps instead, assuming constant frame rate fps. โ ๏ธ this is not the same as the -framerate option used for some input formats like image2 or v4l2 (it used to be the same in older FFmpeg versions, messy era ๐ญ). if in doubt, use -framerate instead of the input option -r.
as an output option:
video encodingโ duplicates or drops frames right before encoding them, so you land on a constant output frame rate of fps. slay โจvideo streamcopyโ tells the muxer that fps is the stream frame rate. no data is dropped or duplicated here. โ ๏ธ this may produce invalid files if fps doesn't match the actual stream frame rate as determined by packet timestamps. see also thesettsbitstream filter. ๐
-fpsmax[:stream_specifier]fps (output,per-stream) โ sets the maximum frame rate (Hz value, fraction or abbreviation).
it clamps the output frame rate when the output framerate is auto-set and comes out higher than this value. super useful in batch processing, or when the input framerate is wrongly detected as very high (looking at you, weird files ๐). it cannot be set together with -r, and it's ignored during streamcopy.
-s[:stream_specifier]size (input/output,per-stream) โ sets the frame size.
as an input option, it's a shortcut for the video_size private option, recognized by some demuxers where the frame size is either not stored in the file or is configurable โ like raw video or video grabbers, fr fr.
as an output option, it inserts the scale video filter at the end of the corresponding filtergraph. if you want it at the beginning or somewhere else, please just use the scale filter directly bestie ๐ซถ
the format is wxh (default โ same as source).
-aspect[:stream_specifier]aspect (output,per-stream) โ sets the video display aspect ratio specified by aspect.
aspect can be a floating point number string, or a string of the form num:den, where num and den are the numerator and denominator of the aspect ratio. for example 4:3, 16:9, 1.3333, and 1.7777 are all valid argument values ๐
if used together with -vcodec copy, it will affect the aspect ratio stored at container level, but not the aspect ratio stored in encoded frames, if it exists. lowkey important ๐
-display_rotation[:stream_specifier]rotation (input,per-stream) โ sets video rotation metadata.
rotation is a decimal number specifying the amount in degrees by which the video should be rotated counter-clockwise before being displayed.
this option overrides the rotation/display transform metadata stored in the file, if any. when the video is being transcoded (rather than copied) and -autorotate is enabled, the video will be rotated at the filtering stage. otherwise, the metadata will be written into the output file if the muxer supports it โจ
if the -display_hflip and/or -display_vflip options are given, they are applied after the rotation specified by this option.
-display_hflip[:stream_specifier](input,per-stream) โ sets whether on display the image should be horizontally flipped. see the-display_rotationoption for more details ๐ฆ-display_vflip[:stream_specifier](input,per-stream) โ sets whether on display the image should be vertically flipped. see the-display_rotationoption for more details ๐ฆ-vn(input/output) โ as an input option, it blocks all video streams of a file from being filtered or being automatically selected or mapped for any output. see the-discardoption if you wanna disable streams individually.
as an output option, it disables video recording, i.e. automatic selection or mapping of any video stream. for full manual control see the -map option ๐
-vcodeccodec (output) โ sets the video codec. this is an alias for-codec:v.-pass[:stream_specifier]n (output,per-stream) โ selects the pass number (1or2). it's used for two-pass video encoding. the statistics of the video are recorded in the first pass into a log file (see also the option-passlogfile), and in the second pass that log file is used to generate the video at the exact requested bitrate. on pass 1, you may just deactivate audio and set output to null โ examples for Windows and Unix:
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
-passlogfile[:stream_specifier]prefix (output,per-stream) โ sets the two-pass log file name prefix to prefix. the default file name prefix isffmpeg2pass. the complete file name will bePREFIX-N.log, whereNis a number specific to the output stream ๐-vffiltergraph (output) โ creates the filtergraph specified by filtergraph and uses it to filter the stream. this is an alias for-filter:v, see the-filteroption.-autorotateโ automatically rotates the video according to file metadata. enabled by default, use-noautorotateto disable it โจ-autoscaleโ automatically scales the video according to the resolution of the first frame. enabled by default, use-noautoscaleto disable it.
โ ๏ธ when autoscale is disabled, all output frames of the filter graph might not be in the same resolution and may be inadequate for some encoder/muxer. therefore, it's not recommended to disable it unless you really know what you're doing. disable autoscale at your own risk ๐
๐ Advanced Video options ๐
-pix_fmt[:stream_specifier]format (input/output,per-stream) โ sets the pixel format. use-pix_fmtsto show all the supported pixel formats. if the selected pixel format can't be selected, ffmpeg will print a warning and pick the best pixel format supported by the encoder. if pix_fmt is prefixed by a+, ffmpeg will exit with an error if the requested pixel format can't be selected, and automatic conversions inside filtergraphs are disabled. if pix_fmt is a single+, ffmpeg selects the same pixel format as the input (or graph output) and automatic conversions are disabled. iykyk ๐-sws_flagsflags (input/output) โ sets default flags for the libswscale library. these flags are used by automatically insertedscalefilters and those within simple filtergraphs, if not overridden within the filtergraph definition. see the ffmpeg-scaler manual for a list of scaler options โจ-rc_override[:stream_specifier]override (output,per-stream) โ rate control override for specific intervals, formatted as anint,int,intlist separated with slashes. the first two values are the beginning and end frame numbers, the last one is the quantizer to use if positive, or the quality factor if negative.-vstatsโ dumps video coding statistics tovstats_HHMMSS.log. see the vstats file format section for the format description ๐-vstats_filefile โ dumps video coding statistics to file. see the vstats file format section for the format description ๐-vstats_versionfile โ specifies which version of the vstats format to use. default is2. see the vstats file format section for the format description ๐-vtagfourcc/tag (output) โ forces video tag/fourcc. this is an alias for-tag:v.-force_key_frames[:stream_specifier]time[,time...] (output,per-stream)-force_key_frames[:stream_specifier]expr:expr (output,per-stream)-force_key_frames[:stream_specifier]source (output,per-stream)-force_key_frames[:stream_specifier]scd_metadata (output,per-stream)
force_key_frames can take arguments of the following form:
๐ time[,time...]
if the argument consists of timestamps, ffmpeg will round the specified times to the nearest output timestamp as per the encoder time base and force a keyframe at the first frame having a timestamp equal to or greater than the computed timestamp. โ ๏ธ note that if the encoder time base is too coarse, then the keyframes may be forced on frames with timestamps lower than the specified time. the default encoder time base is the inverse of the output framerate but may be set otherwise via -enc_time_base.
if one of the times is "chapters"[delta], it is expanded into the time of the beginning of all chapters in the file, shifted by delta, expressed as a time in seconds. this option can be useful to ensure that a seek point is present at a chapter mark or any other designated place in the output file ๐ซถ
for example, to insert a key frame at 5 minutes, plus key frames 0.1 second before the beginning of every chapter:
-force_key_frames 0:05:00,chapters-0.1
๐ expr:expr
if the argument is prefixed with expr:, the string expr is interpreted like an expression and is evaluated for each frame. a key frame is forced in case the evaluation is non-zero โจ
the expression in expr can contain the following constants:
nโ the number of the current processed frame, starting from0n_forcedโ the number of forced framesprev_forced_nโ the number of the previous forced frame, it isNANwhen no keyframe was forced yetprev_forced_tโ the time of the previous forced frame, it isNANwhen no keyframe was forced yettโ the time of the current processed frame
for example, to force a key frame every 5 seconds, you can specify:
-force_key_frames expr:gte(t,n_forced*5)
to force a key frame 5 seconds after the time of the last forced one, starting from second 13:
-force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))
๐ source
if the argument is source, ffmpeg will force a key frame if the current frame being encoded is marked as a key frame in its source. in cases where this particular source frame has to be dropped, enforce the next available frame to become a key frame instead ๐
scd_metadata ๐ฌ
Okay so if the argument is scd_metadata, ffmpeg will force a key frame if the current frame contains a metadata entry with the key "lavfi.scd.time". The metadata can be added by filters like scdet and scdet_vulkan. Avoid inserting filters that duplicate frames after scdet, because that can cause duplicate metadata for multiple frames and repeated insertion of key frames. ๐ญ
โ ๏ธ Note that forcing too many keyframes is very harmful for the lookahead algorithms of certain encoders: using fixed-GOP options or similar would be more efficient. fr fr.
-apply_cropping[:stream_specifier] source (input,per-stream) โ๏ธ
Automatically crop the video after decoding according to file metadata. Default is all. ๐
none(0) โ Don't apply any cropping metadata.all(1) โ Apply both codec and container level croppping. This is the default mode. ๐codec(2) โ Apply codec level croppping.container(3) โ Apply container level croppping.
-copyinkf[:stream_specifier] (output,per-stream) ๐
When doing stream copy, copy also non-key frames found at the beginning. Lowkey niche but useful.
-init_hw_device type[=name][:device[,key=value...]] ๐ ๏ธ
Initialise a new hardware device of type type called name, using the given device parameters. If no name is specified it will receive a default name of the form type%d. โจ
The meaning of device and the following arguments depends on the device type:
cuda ๐ฉ
device is the number of the CUDA device.
The following options are recognized:
primary_ctxโ If set to1, uses the primary device context instead of creating a new one.
Examples:
-init_hw_device cuda:1
Choose the second device on the system.
-init_hw_device cuda:0,primary_ctx=1
Choose the first device and use the primary device context.
dxva2 ๐ช
device is the number of the Direct3D 9 display adapter.
d3d11va ๐ชโจ
device is the number of the Direct3D 11 display adapter. If not specified, it will attempt to use the default Direct3D 11 display adapter or the first Direct3D 11 display adapter whose hardware VendorId is specified by vendor_id.
Examples:
-init_hw_device d3d11va
Create a d3d11va device on the default Direct3D 11 display adapter.
-init_hw_device d3d11va:1
Create a d3d11va device on the Direct3D 11 display adapter specified by index 1.
-init_hw_device d3d11va:,vendor_id=0x8086
Create a d3d11va device on the first Direct3D 11 display adapter whose hardware VendorId is 0x8086.
vaapi ๐ง
device is either an X11 display name, a DRM render node or a DirectX adapter index. If not specified, it will attempt to open the default X11 display ($DISPLAY) and then the first DRM render node (/dev/dri/renderD128), or the default DirectX adapter on Windows.
The following options are recognized:
kernel_driverโ Whendeviceis not specified, use this option to specify the name of the kernel driver associated with the desired device. This option is available only when the hardware acceleration methoddrmandvaapiare enabled.vendor_idโ Whendeviceandkernel_driverare not specified, use this option to specify the vendor id associated with the desired device. This option is available only when the hardware acceleration methoddrmandvaapiare enabled andkernel_driveris not specified.
Examples:
-init_hw_device vaapi
Create a vaapi device on the default device.
-init_hw_device vaapi:/dev/dri/renderD129
Create a vaapi device on DRM render node /dev/dri/renderD129.
-init_hw_device vaapi:1
Create a vaapi device on DirectX adapter 1.
-init_hw_device vaapi:,kernel_driver=i915
Create a vaapi device on a device associated with kernel driver i915.
-init_hw_device vaapi:,vendor_id=0x8086
Create a vaapi device on a device associated with vendor id 0x8086.
vdpau ๐ง
device is an X11 display name. If not specified, it will attempt to open the default X11 display ($DISPLAY).
qsv ๐
qsv device selects a value in MFX_IMPL_*. Allowed values are:
autoswhwauto_anyhw_anyhw2hw3hw4
If not specified, auto_any is used. (Note that it may be easier to achieve the desired result for QSV by creating the platform-appropriate subdevice (dxva2 or d3d11va or vaapi) and then deriving a QSV device from that.)
The following options are recognized:
child_deviceโ Specify a DRM render node on Linux or DirectX adapter on Windows.child_device_typeโ Choose platform-appropriate subdevice type. On Windowsd3d11vais used as default subdevice type when--enable-libvplis specified at configuration time,dxva2is used as default subdevice type when--enable-libmfxis specified at configuration time. On Linux user can usevaapionly as subdevice type.
Examples:
-init_hw_device qsv:hw,child_device=/dev/dri/renderD129
Create a QSV device with MFX_IMPL_HARDWARE on DRM render node /dev/dri/renderD129.
-init_hw_device qsv:hw,child_device=1
Create a QSV device with MFX_IMPL_HARDWARE on DirectX adapter 1.
-init_hw_device qsv:hw,child_device_type=d3d11va
Choose the GPU subdevice with type d3d11va and create QSV device with MFX_IMPL_HARDWARE.
-init_hw_device qsv:hw,child_device_type=dxva2
Choose the GPU subdevice with type dxva2 and create QSV device with MFX_IMPL_HARDWARE.
-init_hw_device qsv:hw,child_device=1,child_device_type=d3d11va
Create a QSV device with MFX_IMPL_HARDWARE on DirectX adapter 1 with subdevice type d3d11va.
-init_hw_device vaapi=va:/dev/dri/renderD129 -init_hw_device qsv=hw1@va
Create a VAAPI device called va on /dev/dri/renderD129, then derive a QSV device called hw1 from device va.
opencl ๐
device selects the platform and device as platform_index.device_index.
The set of devices can also be filtered using the key-value pairs to find only devices matching particular platform or device strings.
The strings usable as filters are:
platform_profileplatform_versionplatform_nameplatform_vendorplatform_extensionsdevice_namedevice_vendordriver_versiondevice_versiondevice_profiledevice_extensionsdevice_type
The indices and filters must together uniquely select a device. iykyk ๐
Examples:
-init_hw_device opencl:0.1
Choose the second device on the first platform.
-init_hw_device opencl:,device_name=Foo9000
Choose the device with a name containing the string Foo9000.
-init_hw_device opencl:1,device_type=gpu,device_extensions=cl_khr_fp16
Choose the GPU device on the second platform supporting the cl_khr_fp16 extension.
vulkan ๐ฅ
If device is an integer, it selects the device by its index in a system-dependent list of devices. If device is any other string, it selects the first device with a name containing that string as a substring.
The following options are recognized:
debugโ If set to1, enables the validation layer, if installed.linear_imagesโ If set to1, images allocated by thehwcontextwill be linear and locally mappable.instance_extensionsโ A plus separated list of additional instance extensions to enable.device_extensionsโ A plus separated list of additional device extensions to enable.
Examples:
-init_hw_device vulkan:1
Choose the second device on the system.
-init_hw_device vulkan:RADV
Choose the first device with a name containing the string RADV.
-init_hw_device vulkan:0,instance_extensions=VK_KHR_wayland_surface+VK_KHR_xcb_surface
Choose the first device and enable the Wayland and XCB instance extensions.
-init_hw_device type[=name]@source ๐งฌ
Initialise a new hardware device of type type called name, deriving it from the existing device with the name source.
-init_hw_device list ๐
List all hardware device types supported in this build of ffmpeg.
-filter_hw_device name ๐๏ธ
Pass the hardware device called name to all filters in any filter graph. This can be used to set the device to upload to with the hwupload filter, or the device to map to with the hwmap filter. Other filters may also make use of this parameter when they require a hardware device. Note that this is typically only required when the input is not already in hardware frames โ when it is, filters will derive the device they require from the context of the frames they receive as input.
This is a global setting, so all filters will receive the same device. ๐
-hwaccel[:stream_specifier] hwaccel (input,per-stream) โก
Use hardware acceleration to decode the matching stream(s). The allowed values of hwaccel are:
noneโ Do not use any hardware acceleration (the default).autoโ Automatically select the hardware acceleration method.vdpauโ Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.dxva2โ Use DXVA2 (DirectX Video Acceleration) hardware acceleration.d3d11vaโ Use D3D11VA (DirectX Video Acceleration) hardware acceleration.vaapiโ Use VAAPI (Video Acceleration API) hardware acceleration.qsvโ Use the Intel QuickSync Video acceleration for video transcoding.
Okay so unlike most other values, this option does not enable accelerated decoding (that's used automatically whenever a qsv decoder is selected) โ it enables accelerated transcoding, without copying the frames into the system memory.
For it to work, both the decoder and the encoder must support QSV acceleration and no filters must be used. No filters, bestie. Periodt.
videotoolboxโ Use Video Toolbox hardware acceleration. Slay.
This option has no effect if the selected hwaccel is not available or not supported by the chosen decoder.
Note that most acceleration methods are intended for playback and will not be faster than software decoding on modern CPUs. Additionally, ffmpeg will usually need to copy the decoded frames from the GPU memory into the system memory, resulting in further performance loss. This option is thus mainly useful for testing. So don't expect magic, bestie โ it's giving "testing only" energy. ๐
-hwaccel_device[:stream_specifier]hwaccel_device (input,per-stream) โ Select a device to use for hardware acceleration.
This option only makes sense when the -hwaccel option is also specified. It can either refer to an existing device created with -init_hw_device by name, or it can create a new device as if -init_hw_device type:hwaccel_device were called immediately before. It's giving "pick your device, bestie" โจ
-hwaccelsโ List all hardware acceleration components enabled in this build offfmpeg. Actual runtime availability depends on the hardware and its suitable driver being installed. So like, it's a list, but your hardware might still say "nah" ๐-fix_sub_duration_heartbeat[:stream_specifier]โ Set a specific output video stream as the heartbeat stream according to which to split and push through currently in-progress subtitle upon receipt of a random access packet.
This lowers the latency of subtitles for which the end packet or the following subtitle has not yet been received. As a drawback, this will most likely lead to duplication of subtitle events in order to cover the full duration, so when dealing with use cases where latency of when the subtitle event is passed on to output is not relevant this option should not be utilized. So it's a whole vibe, but only if you actually need low latency.
Requires -fix_sub_duration to be set for the relevant input subtitle stream for this to have any effect, as well as for the input subtitle stream having to be directly mapped to the same output in which the heartbeat stream resides. No prerequisites, no effect โ that's the rule. ๐ซถ
๐ถ Audio Options ๐ถ
Okay bestie, let's talk audio. These options are giving main character energy for your sound streams. ๐ง
-aframesnumber (output) โ Set the number of audio frames to output. This is an obsolete alias for-frames:a, which you should use instead. So like, it's deprecated โ don't use it, use the other one. Periodt. ๐-ar[:stream_specifier]freq (input/output,per-stream) โ Set the audio sampling frequency. For output streams it is set by default to the frequency of the corresponding input stream. For input streams this option only makes sense for audio grabbing devices and raw demuxers and is mapped to the corresponding demuxer options. So if you're grabbing audio from a device, this is your girl. ๐-aqq (output) โ Set the audio quality (codec-specific, VBR). This is an alias for-q:a. Slay. โจ-ac[:stream_specifier]channels (input/output,per-stream) โ Set the number of audio channels. For output streams it is set by default to the number of input audio channels. For input streams this option only makes sense for audio grabbing devices and raw demuxers and is mapped to the corresponding demuxer options. Same vibe as-ar, bestie. ๐-an(input/output) โ As an input option, blocks all audio streams of a file from being filtered or being automatically selected or mapped for any output. See-discardoption to disable streams individually.
As an output option, disables audio recording i.e. automatic selection or mapping of any audio stream. For full manual control see the -map option. So it's like a mute button, but you can still map manually if you want. ๐
-acodeccodec (input/output) โ Set the audio codec. This is an alias for-codec:a. Iconic. ๐-sample_fmt[:stream_specifier]sample_fmt (output,per-stream) โ Set the audio sample format. Use-sample_fmtsto get a list of supported sample formats. So like, check the list first, bestie. ๐-affiltergraph (output) โ Create the filtergraph specified by filtergraph and use it to filter the stream.
This is an alias for -filter:a, see the -filter option. Filters are literally the moment. ๐ฆ
๐ Advanced Audio options ๐
Okay, now we're getting fancy. Advanced audio stuff, no cap. ๐
-atagfourcc/tag (output) โ Force audio tag/fourcc. This is an alias for-tag:a. Slay. โจ-ch_layout[:stream_specifier]layout (input/output,per-stream) โ Alias for-channel_layout. So it's the same thing, just shorter. Love that for us. ๐-channel_layout[:stream_specifier]layout (input/output,per-stream) โ Set the audio channel layout. For output streams it is set by default to the input channel layout. For input streams it overrides the channel layout of the input. Not all decoders respect the overridden channel layout. This option also sets the channel layout for audio grabbing devices and raw demuxers and is mapped to the corresponding demuxer option. So it's giving "layout queen" but with a warning: not all decoders will listen. ๐-guess_layout_maxchannels (input,per-stream) โ If some input channel layout is not known, try to guess only if it corresponds to at most the specified number of channels. For example,2tells toffmpegto recognize 1 channel as mono and 2 channels as stereo but not 6 channels as 5.1. The default is to always try to guess. Use0to disable all guessing. Using the-channel_layoutoption to explicitly specify an input layout also disables guessing. So like, if you're like "idk what this is",ffmpegwill try to guess, but you can cap it. Bestie, use0to stop the guessing games. ๐ฒ
๐ Subtitle options ๐
Subtitles are literally the vibe. Let's get into it. ๐ฌ
-scodeccodec (input/output) โ Set the subtitle codec. This is an alias for-codec:s. Slay. ๐-sn(input/output) โ As an input option, blocks all subtitle streams of a file from being filtered or being automatically selected or mapped for any output. See-discardoption to disable streams individually.
As an output option, disables subtitle recording i.e. automatic selection or mapping of any subtitle stream. For full manual control see the -map option. So it's the subtitle mute button, basically. ๐คซ
๐ง Advanced Subtitle options ๐ง
Okay, advanced subtitle hours. This is where the fairy dust comes in. โจ
-fix_sub_durationโ Fix subtitles durations. For each subtitle, wait for the next packet in the same stream and adjust the duration of the first to avoid overlap. This is necessary with some subtitles codecs, especially DVB subtitles, because the duration in the original packet is only a rough estimate and the end is actually marked by an empty subtitle frame. Failing to use this option when necessary can result in exaggerated durations or muxing failures due to non-monotonic timestamps.
Note that this option will delay the output of all data until the next subtitle packet is decoded: it may increase memory consumption and latency a lot.
So it's giving "fix it but also maybe slow things down", bestie. Use with caution. ๐ญ
-canvas_sizesize โ Set the size of the canvas used to render subtitles. So like, the canvas size, periodt. ๐จ
๐ Advanced options ๐
This is the big one. Advanced options, main character energy. Let's go. ๐
-map[-]input_file_id[:stream_specifier][:view_specifier][:?] | [linklabel](output) โ Create one or more streams in the output file. This option has two forms for specifying the data source(s): the first selects one or more streams from some input file (specified with-i), the second takes an output from some complex filtergraph (specified with-filter_complex).
In the first form, an output stream is created for every stream from the input file with the index input_file_id. If stream_specifier is given, only those streams that match the specifier are used (see the Stream specifiers section for the stream_specifier syntax).
A - character before the stream identifier creates a "negative" mapping. It disables matching streams from already created mappings.
An optional view_specifier may be given after the stream specifier, which for multiview video specifies the view to be used. The view specifier may have one of the following formats:
view:view_idโ select a view by its ID; view_id may be set to'all'to use all the views interleaved into one stream;vidx:view_idxโ select a view by its index; i.e.0is the base view,1is the first non-base view, etc.vpos:positionโ select a view by its display position; position may be"left"or"right"
The default for transcoding is to only use the base view, i.e. the equivalent of vidx:0. For streamcopy, view specifiers are not supported and all views are always copied.
A trailing ? after the stream index will allow the map to be optional: if the map matches no streams the map will be ignored instead of failing. Note the map will still fail if an invalid input file index is used; such as if the map refers to a non-existent input.
An alternative [linklabel] form will map outputs from complex filter graphs (see the -filter_complex option) to the output file. linklabel must correspond to a defined output link label in the graph.
This option may be specified multiple times, each adding more streams to the output file. Any given input stream may also be mapped any number of times as a source for different output streams, e.g. in order to use different encoding options and/or filters. The streams are created in the output in the same order in which the -map options are given on the commandline.
Using this option disables the default mappings for this output file.
Examples:
map everything โ To map ALL streams from the first input file to output
ffmpeg -i INPUT -map 0 output
select specific stream โ If you have two audio streams in the first input file, these streams are identified by 0:0 and 0:1. You can use -map to select which streams to place in an output file. For example:
ffmpeg -i INPUT -map 0:1 out.wav
will map the second input stream in INPUT to the (single) output stream in out.wav.
create multiple streams โ To select the stream with index 2 from input file a.mov (specified by the identifier 0:2), and stream with index 6 from input b.mov (specified by the identifier 1:6), and copy them to the output file out.mov:
ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
create multiple streams 2 โ To select all video and the third audio stream from an input file:
ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
negative map โ To map all the streams except the second audio, use negative mappings
ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
optional map โ To map the video and audio streams from the first input, and using the trailing ?, ignore the audio mapping if no audio streams exist in the first input:
ffmpeg -i INPUT -map 0:v -map 0:a? OUTPUT
map by language โ okay so if you only want the English audio stream, bestie, itโs literally this:
ffmpeg -i INPUT -map 0:m:language:eng OUTPUT
-ignore_unknownโ ignore input streams with unknown type instead of failing if copying such streams is attempted. No dramatic exit, just vibes ๐-copy_unknownโ allow input streams with unknown type to be copied instead of failing if copying such streams is attempted. Let the mystery streams through ๐ซถ-map_metadata[:metadata_spec_out] infile[:metadata_spec_in](output, per-metadata) โ set metadata information of the next output file frominfile. Important: those are file indices (zero-based), not filenames. The optionalmetadata_spec_in/metadata_spec_outparameters specify which metadata to copy. A metadata specifier can have these forms:gโ global metadata, i.e. metadata that applies to the whole file.s[:stream_spec]โ per-stream metadata.stream_specis a stream specifier as described in the Stream specifiers chapter. In an input metadata specifier, the first matching stream is copied from. In an output metadata specifier, all matching streams are copied to.c:chapter_indexโ per-chapter metadata.chapter_indexis the zero-based chapter index.p:program_indexโ per-program metadata.program_indexis the zero-based program index.
If the metadata specifier is omitted, it defaults to global.
By default, global metadata is copied from the first input file, and per-stream and per-chapter metadata is copied along with streams/chapters. These default mappings are disabled by creating any mapping of the relevant type. A negative file index can be used to create a dummy mapping that just disables automatic copying.
For example, to copy metadata from the first stream of the input file to global metadata of the output file:
ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
To do the reverse, i.e. copy global metadata to all audio streams:
ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
And yeah, plain 0 would work as well in this example, since global metadata is assumed by default. Slay โจ
-map_chapters input_file_index(output) โ copy chapters from the input file with indexinput_file_indexto the next output file. If no chapter mapping is specified, then chapters are copied from the first input file with at least one chapter. Use a negative file index to disable any chapter copying. Chapter chaos: cancelled ๐-benchmark(global) โ show benchmarking information at the end of an encode. It shows real, system, and user time used and maximum memory consumption. Maximum memory consumption is not supported on all systems; it will usually display as0if not supported. Receipts at the end, periodt ๐-benchmark_all(global) โ show benchmarking information during the encode. It shows real, system, and user time used in various steps (audio/video encode/decode). Live updates, main character energy ๐ฅ-timelimit duration(global) โ exit after ffmpeg has been running fordurationseconds in CPU user time. A little timeout moment โณ-dump(global) โ dump each input packet to stderr. Packet tea, spilled ๐ซ-hex(global) โ when dumping packets, also dump the payload. Now with extra hex-y detail ๐ง-readrate speed(input) โ limit input read speed. Its value is a floating-point positive number which represents the maximum duration of media, in seconds, that should be ingested in one second of wallclock time. Default value is zero and represents no imposed limitation on speed of ingestion. Value1represents real-time speed and is equivalent to-re.
Mainly used to simulate a capture device or live input stream (e.g. when reading from a file). Should not be used with a low value when the input is an actual capture device or live stream, as it may cause packet loss.
It is useful for when flow speed of output packets is important, such as live streaming. Vibe check: controlled ๐ฆ
-re(input) โ read input at native frame rate. This is equivalent to setting-readrate 1. The classic real-time era ๐-readrate_initial_burst secondsโ set an initial read burst time, in seconds, after which-re/-readratewill be enforced. A little warm-up sprint before the speed rules kick in ๐โโ๏ธ-readrate_catchup speed(input) โ if either the input or output is blocked, leading to actual read speed falling behind the specified readrate, then this rate takes effect till the input catches up with the specified readrate. Must not be lower than the primary readrate. Catch-up era, no cap ๐-vsync parameter(global) /-fps_mode[:stream_specifier] parameter(output, per-stream) โ set video sync method / framerate mode.vsyncis applied to all output video streams but can be overridden for a stream by settingfps_mode.vsyncis deprecated and will be removed in the future.
For compatibility reasons, some of the values for vsync can be specified as numbers (shown in parentheses):
passthrough (0)โ each frame is passed with its timestamp from the demuxer to the muxer.cfr (1)โ frames will be duplicated and dropped to achieve exactly the requested constant frame rate.vfr (2)โ frames are passed through with their timestamp or dropped so as to prevent 2 frames from having the same timestamp.auto (-1)โ chooses betweencfrandvfrdepending on muxer capabilities. This is the default method.
Note that the timestamps may be further modified by the muxer, after this. For example, in the case that the format option avoid_negative_ts is enabled.
With -map you can select from which stream the timestamps should be taken. You can leave either video or audio unchanged and sync the remaining stream(s) to the unchanged one. Iconic timestamp diplomacy ๐
-frame_drop_threshold parameterโ frame drop threshold, which specifies how much behind video frames can be before they are dropped. In frame rate units, so1.0is one frame. The default is-1.1. One possible usecase is to avoid framedrops in case of noisy timestamps or to increase frame drop precision in case of exact timestamps. Drop it like itโs hot, but precisely ๐-apad parameters(output, per-stream) โ pad the output audio stream(s). This is the same as applying-af apad. Argument is a string of filter parameters composed the same as with theapadfilter.-shortestmust be set for this output for the option to take effect. Audio padding, but make it fashion ๐ง-copytsโ do not process input timestamps, but keep their values without trying to sanitize them. In particular, do not remove the initial start time offset value.
Note that, depending on the vsync option or on specific muxer processing (e.g. in case the format option avoid_negative_ts is enabled), the output timestamps may mismatch with the input timestamps even when this option is selected. Timestamps: preserved, not necessarily matching. Itโs giving โtrust the processโ ๐ญ
-start_at_zeroโ when used withcopyts, shift input timestamps so they start at zero. This means that using e.g.-ss 50will make output timestamps start at 50 seconds, regardless of what timestamp the input file started at. Zero is the moment โจ-copytb modeโ specify how to set the encoder timebase when stream copying.modeis an integer numeric value, and can assume one of the following values:1โ use the demuxer timebase. The time base is copied to the output encoder from the corresponding input demuxer. This is sometimes required to avoid non monotonically increasing timestamps when copying video streams with variable frame rate.0โ use the decoder timebase. The time base is copied to the output encoder from the corresponding input decoder.-1โ try to make the choice automatically, in order to generate a sane output.
Default value is -1. Auto-pilot timebase, bestie ๐
-enc_time_base[:stream_specifier] timebase(output, per-stream) โ set the encoder timebase.timebasecan assume one of the following values:0โ assign a default value according to the media type. For video, use1/framerate; for audio, use1/samplerate.demuxโ use the timebase from the demuxer.filterโ use the timebase from the filtergraph.- a positive number โ use the provided number as the timebase. This field can be provided as a ratio of two integers (e.g.
1:24,1:48000) or as a decimal number (e.g.0.04166,2.0833e-5).
Default value is 0. Timebase customization is lowkey a flex ๐
-bitexact(input/output) โ enable bitexact mode for (de)muxer and (de/en)coder. Bit-for-bit bestie behavior ๐งฌ-shortest(output) โ finish encoding when the shortest output stream ends. Note that this option may require buffering frames, which introduces extra latency. The maximum amount of this latency may be controlled with the-shortest_buf_durationoption. Shortest stream said โIโm done,โ and everybody packs up ๐ฌ-shortest_buf_duration duration(output) โ the-shortestoption may require buffering potentially large amounts of data when at least one of the streams is โsparseโ (i.e. has large gaps between frames โ this is typically the case for subtitles). This option controls the maximum duration of buffered frames in seconds. Larger values may allow the-shortestoption to produce more accurate results, but increase memory use and latency. The default value is10seconds. Buffering, but make it bounded ๐-dts_delta_threshold thresholdโ timestamp discontinuity delta threshold, expressed as a decimal number of seconds. The timestamp discontinuity correction enabled by this option is only applied to input formats accepting timestamp discontinuity (for which theAVFMT_TS_DISCONTflag is enabled), e.g. MPEG-TS and HLS, and is automatically disabled when employing the-copytsoption (unless wrapping is detected). If a timestamp discontinuity is detected whose absolute value is greater thanthreshold, ffmpeg will remove the discontinuity by decreasing/increasing the current DTS and PTS by the corresponding delta value. The default value is10. Timestamp drama: smoothed, fr fr ๐ธ-dts_error_threshold thresholdโ timestamp error delta threshold, expressed as a decimal number of seconds. The timestamp correction enabled by this option is only applied to input formats not accepting timestamp discontinuity (for which theAVFMT_TS_DISCONTflag is not enabled). If a timestamp discontinuity is detected whose absolute value is greater thanthreshold, ffmpeg will drop the PTS/DTS timestamp value. The default value is3600*30(30 hours), which is arbitrarily picked and quite conservative. Weโre not dramatic, weโre just 30 hours patient ๐ญ-muxdelay seconds(output) โ set the maximum demux-decode delay. A tiny bit of mux delay, and weโre out ๐ซถ-muxpreloadseconds (output) โ sets the initial demux-decode delay โจ-streamidoutput-stream-index:new-value (output) โ hands a brand-new stream-id to an output stream, like giving your fave a glow-up name ๐ . Okay so important: this option has to come before the output filename it applies to. And if you've got multiple output files going on, you can absolutely reassign a streamid to a different value, no drama.
For example, setting stream 0's PID to 33 and stream 1's PID to 36 for an output mpegts file is literally just:
ffmpeg -i inurl -streamid 0:33 -streamid 1:36 out.ts
-bsf[:stream_specifier]bitstream_filters (input/output,per-stream) โ applies bitstream filters to the streams that match, bestie ๐. The filters get applied to each packet as it's received from the demuxer (when you use it as an input option) or right before it's sent to the muxer (when you use it as an output option).
bitstream_filters is a comma-separated list of bitstream filter specs, and each one looks like this:
<filter>[=<optname0>=<optval0>:<optname1>=<optval1>:...]
Any ,, = or : characters that need to be part of an option value have to be escaped with a backslash โญ.
Wanna see the whole list of bitstream filters? Use the -bsfs option, iykyk.
E.g.
ffmpeg -bsf:v h264_mp4toannexb -i h264.mp4 -c:v copy -an out.h264
that one applies the h264_mp4toannexb bitstream filter (which converts an MP4-encapsulated H.264 stream to Annex B) to the input video stream, slay.
On the other hand,
ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
applies the mov2textsub bitstream filter (which extracts text from MOV subtitles) to the output subtitle stream. But heads up ๐ โ since both examples use -c copy, it barely matters whether the filters are applied on input or output. That little detail would matter if transcoding was happening, so keep it in mind!
-tag[:stream_specifier]codec_tag (input/output,per-stream) โ forces a tag/fourcc for the streams that match ๐ฅ-timecodehh:mm:ssSEPff โ sets the Timecode for writing. SEP is:for non-drop timecode and;(or.) for drop, periodt.
ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
-filter_complexfiltergraph (global) โ defines a complex filtergraph, aka one with an arbitrary number of inputs and/or outputs ๐ฆ. If you just want a simple graph โ one input, one output, same type โ go look at the-filteroptions instead. filtergraph is a description of the filtergraph, exactly as described in the ``Filtergraph syntax'' section of theffmpeg-filtersmanual. And you can specify this option multiple times: each use creates a brand-new complex filtergraph, iconic.
Inputs to a complex filtergraph can come from different source types, and you tell them apart by the format of the corresponding link label:
- To connect an input stream, use
[file_index:stream_specifier](yep, the same syntax as-map). If stream_specifier matches multiple streams, the first one gets used. For multiview video, the stream specifier may be followed by the view specifier โ check the documentation for the-mapoption for its syntax ๐. - To connect a loopback decoder use
[dec:dec_idx], where dec_idx is the index of the loopback decoder to be connected to the given input. For multiview video, the decoder index may be followed by the view specifier, see the documentation for the-mapoption for its syntax. - To connect an output from another complex filtergraph, use its link label. E.g. the following example:
ffmpeg -i input.mkv \
-filter_complex '[0:v]scale=size=hd1080,split=outputs=2[for_enc][orig_scaled]' \
-c:v libx264 -map '[for_enc]' output.mkv \
-dec 0:0 \
-filter_complex '[dec:0][orig_scaled]hstack[stacked]' \
-map '[stacked]' -c:v ffv1 comparison.mkv
reads an input video and
- (line 2) uses a complex filtergraph with one input and two outputs to scale the video to 1920x1080 and duplicate the result to both outputs;
- (line 3) encodes one scaled output with
libx264and writes the result tooutput.mkv; - (line 4) decodes this encoded stream with a loopback decoder;
- (line 5) places the output of the loopback decoder (i.e. the
libx264-encoded video) side by side with the scaled original input; - (line 6) combined video is then losslessly encoded and written into
comparison.mkv.
Note that the two filtergraphs cannot be combined into one, because then there would be a cycle in the transcoding pipeline (filtergraph output goes to encoding, from there to decoding, then back to the same graph), and such cycles are not allowed ๐. Rules are rules.
An unlabeled input will be connected to the first unused input stream of the matching type โจ.
Output link labels are referred to with -map. Unlabeled outputs are added to the first output file.
Note that with this option it's possible to use only lavfi sources without normal input files โ no cap, main character energy ๐.
For example, to overlay an image over video:
ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
'[out]' out.mkv
Here [0:v] refers to the first video stream in the first input file, which is linked to the first (main) input of the overlay filter. Similarly the first video stream in the second input is linked to the second (overlay) input of overlay ๐.
Assuming there's only one video stream in each input file, we can omit input labels, so the above is equivalent to:
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
'[out]' out.mkv
Furthermore we can omit the output label and the single output from the filter graph will be added to the output file automatically, so we can simply write:
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
As a special exception, you can use a bitmap subtitle stream as input: it will be converted into a video with the same size as the largest video in the file, or 720x576 if no video is present. Note that this is an experimental and temporary solution ๐ซถ. It will be removed once libavfilter has proper support for subtitles.
For example, to hardcode subtitles on top of a DVB-T recording stored in MPEG-TS format, delaying the subtitles by 1 second:
ffmpeg -i input.ts -filter_complex \
'[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
-sn -map '#0x2dc' output.mkv
(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video, audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too ๐)
To generate 5 seconds of pure red video using the lavfi color source:
ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
-filter_complex_threadsnb_threads (global) โ defines how many threads get used to process afilter_complexgraph ๐ฅ. Similar tofilter_threadsbut used for-filter_complexgraphs only. The default is the number of available CPUs, cute.-lavfifiltergraph (global) โ defines a complex filtergraph, i.e. one with arbitrary number of inputs and/or outputs. Equivalent to-filter_complex๐ซ.-accurate_seek(input) โ turns accurate seeking in input files on or off when you're using the-ssoption. It's enabled by default, so seeking is accurate when transcoding ๐ฏ. Use-noaccurate_seekto disable it, which may be useful e.g. when copying some streams and transcoding the others.-seek_timestamp(input) โ turns seeking by timestamp in input files on or off with the-ssoption. Disabled by default. If enabled, the argument to the-ssoption is considered an actual timestamp, and is not offset by the start time of the file โญ. This matters only for files which don't start from timestamp 0, such as transport streams.-thread_queue_sizesize (input/output) โ for input, this option sets the maximum number of queued packets when reading from the file or device. With low latency / high rate live streams, packets may be discarded if they're not read in a timely manner ๐ญ; setting this value can force ffmpeg to use a separate input thread and read packets as soon as they arrive. By default ffmpeg only does this if multiple inputs are specified.
For output, this option specifies the maximum number of packets that may be queued to each muxing thread.
-sdp_filefile (global) โ prints sdp information for an output stream to file ๐. This lets you dump sdp information when at least one output isn't an rtp stream. (Requires at least one of the output formats to be rtp.)-discard(input) โ lets you discard specific streams or frames from streams ๐ฆ. Any input stream can be fully discarded with the valueall, whereas selective discarding of frames from a stream happens at the demuxer and isn't supported by all demuxers. The values are:noneโ discard no frame.defaultโ the default, which discards no frames.norefโ discard all non-reference frames.bidirโ discard all bidirectional frames.nokeyโ discard all frames excepts keyframes.allโ discard all frames.
-abort_onflags (global) โ stop and abort on various conditions ๐. The available flags are:empty_outputโ no packets were passed to the muxer, so the output is empty.empty_output_streamโ no packets were passed to the muxer in some of the output streams.
-max_error_rate(global) โ sets the fraction of decoding frame failures across all inputs which, when crossed, makes ffmpeg return exit code69๐. Crossing this threshold does not terminate processing โ it's just a lil heads-up. Range is a floating-point number between 0 to 1. Default is2/3.-xerror(global) โ stop and exit on error. No notes. ๐-max_muxing_queue_sizepackets (output,per-stream) โ okay so when transcoding audio and/or video streams, ffmpeg won't begin writing into the output until it has one packet for each such stream ๐ธ. While it's waiting for that to happen, packets for other streams are buffered. This option sets the size of that buffer, in packets, for the matching output stream.
The default value of this option should be high enough for most uses, so only touch this option if you're sure that you need it, bestie ๐.
-muxing_queue_data_thresholdbytes (output,per-stream) โ okay so this one's a minimum threshold, and below it the muxing queue size just isn't counted, periodt. It defaults to 50 megabytes per stream, and it's based on the overall size of the packets passed to the muxer. ๐-auto_conversion_filters(global) โ turns on auto-inserting format conversion filters into all the filter graphs, including the ones you define with-vf,-af,-filter_complexand-lavfi. If filter format negotiation needs a conversion and this is off, the filter init just fails ๐ญ. Conversions can still happen tho โ you just insert the relevant conversion filter (scale,aresample) into the graph yourself. It's on by default, so to explicitly disable it you gotta specify-noauto_conversion_filters.-bits_per_raw_sample[:stream_specifier]value (output,per-stream) โ declares that the number of bits per raw sample in the given output stream is value. โ ๏ธ Heads up bestie: this only sets the info handed to the encoder/muxer, it does not change the stream to conform to that value. Setting values that don't match the stream properties may result in encoding failures or straight-up invalid output files. No cap.-stats_enc_pre[:stream_specifier]path (output,per-stream)-stats_enc_post[:stream_specifier]path (output,per-stream)-stats_mux_pre[:stream_specifier]path (output,per-stream) โ write per-frame encoding info about the matching streams into the file given by path. ๐
-stats_enc_pre writes info about raw video or audio frames right before they're sent off for encoding, while -stats_enc_post writes info about encoded packets as they come back from the encoder. -stats_mux_pre writes info about packets just as they're about to be sent to the muxer. Every frame or packet produces one line in the specified file. The format of that line is controlled by -stats_enc_pre_fmt / -stats_enc_post_fmt / -stats_mux_pre_fmt.
When stats for multiple streams get written into a single file, the lines for different streams will be interleaved. The precise order of that interleaving is not specified and not guaranteed to stay stable between different invocations of the program โ even with the same options. ๐
-stats_enc_pre_fmt[:stream_specifier]format_spec (output,per-stream)-stats_enc_post_fmt[:stream_specifier]format_spec (output,per-stream)-stats_mux_pre_fmt[:stream_specifier]format_spec (output,per-stream) โ specify the format for the lines written with-stats_enc_pre/-stats_enc_post/-stats_mux_pre.
format_spec is a string that may contain directives of the form {fmt}. format_spec is backslash-escaped โ use \{, \}, and \\ to write a literal {, }, or \, respectively, into the output.
The directives given with fmt may be one of the following:
fidxโ index of the output file.sidxโ index of the output stream in the file.nโ frame number. Pre-encoding: number of frames sent to the encoder so far. Post-encoding: number of packets received from the encoder so far. Muxing: number of packets submitted to the muxer for this stream so far.niโ input frame number. Index of the input frame (i.e. output by a decoder) that corresponds to this output frame or packet.-1if unavailable.tbโ timebase in which this frame/packet's timestamps are expressed, as a rational number num/den. Note that encoder and muxer may use different timebases.tbiโ timebase forptsi, as a rational number num/den. Available whenptsiis available,0/1otherwise.ptsโ presentation timestamp of the frame or packet, as an integer. Should be multiplied by the timebase to compute presentation time.ptsiโ presentation timestamp of the input frame (seeni), as an integer. Should be multiplied bytbito compute presentation time. Printed as(2^63 - 1 = 9223372036854775807)when not available.tโ presentation time of the frame or packet, as a decimal number. Equal toptsmultiplied bytb.tiโ presentation time of the input frame (seeni), as a decimal number. Equal toptsimultiplied bytbi. Printed asinfwhen not available.dts(packet) โ decoding timestamp of the packet, as an integer. Should be multiplied by the timebase to compute presentation time.dt(packet) โ decoding time of the frame or packet, as a decimal number. Equal todtsmultiplied bytb.sn(frame,audio) โ number of audio samples sent to the encoder so far.samp(frame,audio) โ number of audio samples in the frame.size(packet) โ size of the encoded packet in bytes.br(packet) โ current bitrate in bits per second.abr(packet) โ average bitrate for the whole stream so far, in bits per second,-1if it can't be determined at this point.key(packet) โ character'K'if the packet contains a keyframe, character'N'otherwise.
Directives tagged with packet may only be used with -stats_enc_post_fmt and -stats_mux_pre_fmt.
Directives tagged with frame may only be used with -stats_enc_pre_fmt.
Directives tagged with audio may only be used with audio streams.
The default format strings are:
pre-encoding
{fidx} {sidx} {n} {t}
post-encoding
{fidx} {sidx} {n} {t}
In the future, new items may be added to the end of the default formatting strings. Users who depend on the format staying exactly the same should prescribe it manually. ๐ฎ
Note that stats for different streams written into the same file may have different formats.
๐ Preset files ๐
A preset file contains a sequence of option=value pairs, one for each line, specifying a sequence of options which would be awkward to specify on the command line. Lines starting with the hash ('#') character are ignored and are used to provide comments. Check the presets directory in the FFmpeg source tree for examples. โจ
There are two types of preset files: ffpreset and avpreset files.
ffpreset files
ffpreset files are specified with the vpre, apre, spre, and fpre options. The fpre option takes the filename of the preset instead of a preset name as input and can be used for any kind of codec. For the vpre, apre, and spre options, the options specified in a preset file are applied to the currently selected codec of the same type as the preset option.
The argument passed to the vpre, apre, and spre preset options identifies the preset file to use according to the following rules:
First ffmpeg searches for a file named arg.ffpreset in the directories $FFMPEG_DATADIR (if set), and $HOME/.ffmpeg, and in the datadir defined at configuration time (usually PREFIX/share/ffmpeg) or in a ffpresets folder along the executable on win32, in that order. For example, if the argument is libvpx-1080p, it will search for the file libvpx-1080p.ffpreset. ๐ฆ
If no such file is found, then ffmpeg will search for a file named codec_name-arg.ffpreset in the above-mentioned directories, where codec_name is the name of the codec to which the preset file options will be applied. For example, if you select the video codec with -vcodec libvpx and use -vpre 1080p, then it will search for the file libvpx-1080p.ffpreset.
avpreset files
avpreset files are specified with the pre option. They work similar to ffpreset files, but they only allow encoder-specific options. Therefore, an option=value pair specifying an encoder cannot be used. ๐
When the pre option is specified, ffmpeg will look for files with the suffix .avpreset in the directories $AVCONV_DATADIR (if set), and $HOME/.avconv, and in the datadir defined at configuration time (usually PREFIX/share/ffmpeg), in that order.
First ffmpeg searches for a file named codec_name-arg.avpreset in the above-mentioned directories, where codec_name is the name of the codec to which the preset file options will be applied. For example, if you select the video codec with -vcodec libvpx and use -pre 1080p, then it will search for the file libvpx-1080p.avpreset.
If no such file is found, then ffmpeg will search for a file named arg.avpreset in the same directories.
๐ vstats file format ๐
The -vstats and -vstats_file options enable generation of a file containing statistics about the generated video outputs.
The -vstats_version option controls the format version of the generated file.
With version 1 the format is:
frame= <FRAME> q= <FRAME_QUALITY> PSNR= <PSNR> f_size= <FRAME_SIZE> s_size= <STREAM_SIZE>kB time= <TIMESTAMP> br= <BITRATE>kbits/s avg_br= <AVERAGE_BITRATE>kbits/s
With version 2 the format is:
out= <OUT_FILE_INDEX> st= <OUT_FILE_STREAM_INDEX> frame= <FRAME_NUMBER> q= <FRAME_QUALITY>f PSNR= <PSNR> f_size= <FRAME_SIZE> s_size= <STREAM_SIZE>kB time= <TIMESTAMP> br= <BITRATE>kbits/s avg_br= <AVERAGE_BITRATE>kbits/s
The value corresponding to each key is described below:
avg_brโ average bitrate expressed in Kbits/sbrโ bitrate expressed in Kbits/sframeโ number of encoded frameoutโ out file indexPSNRโ Peak Signal to Noise Ratioqโ quality of the framef_sizeโ encoded packet size expressed as number of bytess_sizeโ stream size expressed in KiBstโ out file stream indextimeโ time of the packettypeโ picture type
See also the -stats_enc options for an alternative way to show encoding statistics. ๐
โจ EXAMPLES โจ
okay bestie, this is the part where the manpage stops explaining and starts showing you the moves ๐
๐น Video and Audio grabbing
If you specify the input format and the device, then ffmpeg can grab video and audio directly โ no cap.
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
Or with an ALSA audio source (mono input, card id 1) instead of OSS:
ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
Note that you must activate the right video source and channel before launching ffmpeg with any TV viewer such as http://linux.bytesex.org/xawtv/ by Gerd Knorr. You also have to set the audio recording levels correctly with a standard mixer. like, actual setup first, bestie โ ffmpeg is not a mind reader ๐
๐ฅ๏ธ X11 grabbing
Grab the X11 display with ffmpeg via:
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg
0.0 is the display.screen number of your X11 server, same as the DISPLAY environment variable.
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg
0.0 is the display.screen number of your X11 server, same as the DISPLAY environment variable. 10 is the x-offset and 20 is the y-offset for the grabbing. offsets! we love a little coordinate moment โจ
๐๏ธ Video and Audio file format conversion
Any supported file format and protocol can serve as input to ffmpeg:
Examples:
- You can use YUV files as input:
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
It will use the files:
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
The Y files use twice the resolution of the U and V files. They are raw files, without header. They can be generated by all decent video decoders. You must specify the size of the image with the -s option if ffmpeg cannot guess it.
- You can input from a raw YUV420P file:
ffmpeg -i /tmp/test.yuv /tmp/out.avi
test.yuv is a file containing raw YUV planar data. Each frame is composed of the Y plane followed by the U and V planes at half vertical and horizontal resolution.
- You can output to a raw YUV420P file:
ffmpeg -i mydivx.avi hugefile.yuv
- You can set several input files and output files:
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
Converts the audio file a.wav and the raw YUV video file a.yuv to MPEG file a.mpg.
- You can also do audio and video conversions at the same time:
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
Converts a.wav to MPEG audio at 22050 Hz sample rate.
- You can encode to several formats at the same time and define a mapping from input stream to output streams:
ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. -map file:index specifies which input stream is used for each output stream, in the order of the definition of output streams. mapping is giving main character energy ๐ฅ
- You can transcode decrypted VOBs:
ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
This is a typical DVD ripping example; the input is a VOB file, the output an AVI file with MPEG-4 video and MP3 audio. Note that in this command we use B-frames so the MPEG-4 stream is DivX5 compatible, and GOP size is 300 which means one intra frame every 10 seconds for 29.97fps input video. Furthermore, the audio stream is MP3-encoded so you need to enable LAME support by passing --enable-libmp3lame to configure. The mapping is particularly useful for DVD transcoding to get the desired audio language.
NOTE: To see the supported input formats, use ffmpeg -demuxers.
- You can extract images from a video, or create a video from many images:
For extracting images from a video:
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
This will extract one video frame per second from the video and will output them in files named foo-001.jpeg, foo-002.jpeg, etc. Images will be rescaled to fit the new WxH values.
If you want to extract just a limited number of frames, you can use the above command in combination with the -frames:v or -t option, or in combination with -ss to start extracting from a certain point in time.
For creating a video from many images:
ffmpeg -f image2 -framerate 12 -i foo-%03d.jpeg -s WxH foo.avi
The syntax foo-%03d.jpeg specifies to use a decimal number composed of three digits padded with zeroes to express the sequence number. It is the same syntax supported by the C printf function, but only formats accepting a normal integer are suitable.
When importing an image sequence, -i also supports expanding shell-like wildcard patterns (globbing) internally, by selecting the image2-specific -pattern_type glob option.
For example, for creating a video from filenames matching the glob pattern foo-*.jpeg:
ffmpeg -f image2 -pattern_type glob -framerate 12 -i 'foo-*.jpeg' -s WxH foo.avi
- You can put many streams of the same type in the output:
ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut
The resulting output file test12.nut will contain the first four streams from the input files in reverse order. reverse order?? chaotic, but make it fashion ๐
- To force CBR video output:
ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
- The four options
lmin,lmax,mblminandmblmaxuse 'lambda' units, but you may use theQP2LAMBDAconstant to easily convert from 'q' units:
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
๐ง SYNTAX ๐ง
This section documents the syntax and formats employed by the FFmpeg libraries and tools. yes bestie, we're getting into the grammar of it all โจ
๐ค Quoting and escaping
FFmpeg adopts the following quoting and escaping mechanism, unless explicitly specified. The following rules are applied:
'and\are special characters (respectively used for quoting and escaping). In addition to them, there might be other special characters depending on the specific syntax where the escaping and quoting are employed.- A special character is escaped by prefixing it with a
\. - All characters enclosed between
''are included literally in the parsed string. The quote character'itself cannot be quoted, so you may need to close the quote and escape it. - Leading and trailing whitespaces, unless escaped or quoted, are removed from the parsed string.
Note that you may need to add a second level of escaping when using the command line or a script, which depends on the syntax of the adopted shell language.
The function av_get_token defined in libavutil/avstring.h can be used to parse a token quoted or escaped according to the rules defined above.
The tool tools/ffescape in the FFmpeg source tree can be used to automatically quote or escape a string in a script.
Examples:
- Escape the string "Crime d'Amour" containing the
'special character:
Crime d\'Amour
- The string above contains a quote, so the
'needs to be escaped when quoting it:
'Crime d'\''Amour'
- Include leading or trailing whitespaces using quoting:
' this string starts and ends with whitespaces '
- Escaping and quoting can be mixed together:
' The string '\'string\'' is a string '
- To include a literal
\you can use either escaping or quoting:
'c:\foo' can be written as c:\\foo
๐ Date
The accepted syntax is:
[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
now
If the value is now it takes the current time.
Time is local time unless Z is appended, in which case it is interpreted as UTC. If the year-month-day part is not specified it takes the current year-month-day. timezone behavior, we love a precise queen ๐ซถ
โฑ๏ธ Time duration
There are two accepted syntaxes for expressing time duration.
[-][<HH>:]<MM>:<SS>[.<m>...]
HH expresses the number of hours, MM the number of minutes for a maximum of 2 digits, and SS the number of seconds for a maximum of 2 digits. The m at the end expresses decimal value for SS.
or
[-]<S>+[.<m>...][s|ms|us]
S expresses the number of seconds, with the optional decimal part m. The optional literal suffixes s, ms or us indicate to interpret the value as seconds, milliseconds or microseconds, respectively.
In both expressions, the optional - indicates negative duration.
Examples:
The following examples are all valid time duration:
55โ 55 seconds0.2โ 0.2 seconds200msโ 200 milliseconds, that's 0.2s200000usโ 200000 microseconds, that's 0.2s12:03:45โ 12 hours, 03 minutes and 45 seconds23.189โ 23.189 seconds
๐ Video size
Specify the size of the sourced video, it may be a string of the form widthxheight, or the name of a size abbreviation.
The following abbreviations are recognized:
ntscโ720x480palโ720x576qntscโ352x240qpalโ352x288sntscโ640x480spalโ768x576filmโ352x240ntsc-filmโ352x240sqcifโ128x96qcifโ176x144cifโ352x2884cifโ704x57616cifโ1408x1152qqvgaโ160x120qvgaโ320x240vgaโ640x480svgaโ800x600xgaโ1024x768uxgaโ1600x1200qxgaโ2048x1536sxgaโ1280x1024qsxgaโ2560x2048hsxgaโ5120x4096wvgaโ852x480wxgaโ1366x768wsxgaโ1600x1024wuxgaโ1920x1200woxgaโ2560x1600wqsxgaโ3200x2048wquxgaโ3840x2400whsxgaโ6400x4096whuxgaโ7680x4800cgaโ320x200egaโ640x350hd480โ852x480hd720โ1280x720hd1080โ1920x10802kโ2048x10802kflatโ1998x10802kscopeโ2048x8584kโ4096x21604kflatโ3996x21604kscopeโ4096x1716nhdโ640x360hqvgaโ240x160wqvgaโ400x240fwqvgaโ432x240hvgaโ480x320qhdโ960x5402kdciโ2048x10804kdciโ4096x2160uhd2160โ3840x2160uhd4320โ7680x4320
๐๏ธ Video rate
Specify the frame rate of a video, expressed as the number of frames generated per second. It has to be a string in the format frame_rate_num/frame_rate_den, an integer number, a float number or a valid video frame rate abbreviation. frame rate lore, honestly iconic โจ
okay so these abbreviations are recognized, bestie โ write them down, theyโre literally the shorthand:
ntscโ30000/1001palโ25/1qntscโ30000/1001qpalโ25/1sntscโ30000/1001spalโ25/1filmโ24/1ntsc-filmโ24000/1001
๐ Ratio ๐
A ratio can be expressed as an expression, or in the form numerator:denominator.
โ ๏ธ bestie, a ratio with infinite (1/0) or negative value is considered valid, so you should check on the returned value if you want to exclude those values. Not me making the rules, Iโm just reporting them.
The undefined value can be expressed using the "0:0" string.
๐จ Color ๐จ
It can be the name of a color as defined below (case insensitive match) or a [0x|#]RRGGBB[AA] sequence, possibly followed by @ and a string representing the alpha component.
The alpha component may be a string composed by 0x followed by an hexadecimal number or a decimal number between 0.0 and 1.0, which represents the opacity value (0x00 or 0.0 means completely transparent, 0xff or 1.0 completely opaque). If the alpha component is not specified then 0xff is assumed.
The string random will result in a random color.
The following names of colors are recognized โ yes, all of them, this palette is iconic:
AliceBlueโ0xF0F8FFAntiqueWhiteโ0xFAEBD7Aquaโ0x00FFFFAquamarineโ0x7FFFD4Azureโ0xF0FFFFBeigeโ0xF5F5DCBisqueโ0xFFE4C4Blackโ0x000000BlanchedAlmondโ0xFFEBCDBlueโ0x0000FFBlueVioletโ0x8A2BE2Brownโ0xA52A2ABurlyWoodโ0xDEB887CadetBlueโ0x5F9EA0Chartreuseโ0x7FFF00Chocolateโ0xD2691ECoralโ0xFF7F50CornflowerBlueโ0x6495EDCornsilkโ0xFFF8DCCrimsonโ0xDC143CCyanโ0x00FFFFDarkBlueโ0x00008BDarkCyanโ0x008B8BDarkGoldenRodโ0xB8860BDarkGrayโ0xA9A9A9DarkGreenโ0x006400DarkKhakiโ0xBDB76BDarkMagentaโ0x8B008BDarkOliveGreenโ0x556B2FDarkorangeโ0xFF8C00DarkOrchidโ0x9932CCDarkRedโ0x8B0000DarkSalmonโ0xE9967ADarkSeaGreenโ0x8FBC8FDarkSlateBlueโ0x483D8BDarkSlateGrayโ0x2F4F4FDarkTurquoiseโ0x00CED1DarkVioletโ0x9400D3DeepPinkโ0xFF1493DeepSkyBlueโ0x00BFFFDimGrayโ0x696969DodgerBlueโ0x1E90FFFireBrickโ0xB22222FloralWhiteโ0xFFFAF0ForestGreenโ0x228B22Fuchsiaโ0xFF00FFGainsboroโ0xDCDCDCGhostWhiteโ0xF8F8FFGoldโ0xFFD700GoldenRodโ0xDAA520Grayโ0x808080Greenโ0x008000GreenYellowโ0xADFF2FHoneyDewโ0xF0FFF0HotPinkโ0xFF69B4IndianRedโ0xCD5C5CIndigoโ0x4B0082Ivoryโ0xFFFFF0Khakiโ0xF0E68CLavenderโ0xE6E6FALavenderBlushโ0xFFF0F5LawnGreenโ0x7CFC00LemonChiffonโ0xFFFACDLightBlueโ0xADD8E6LightCoralโ0xF08080LightCyanโ0xE0FFFFLightGoldenRodYellowโ0xFAFAD2LightGreenโ0x90EE90LightGreyโ0xD3D3D3LightPinkโ0xFFB6C1LightSalmonโ0xFFA07ALightSeaGreenโ0x20B2AALightSkyBlueโ0x87CEFALightSlateGrayโ0x778899LightSteelBlueโ0xB0C4DELightYellowโ0xFFFFE0Limeโ0x00FF00LimeGreenโ0x32CD32Linenโ0xFAF0E6Magentaโ0xFF00FFMaroonโ0x800000MediumAquaMarineโ0x66CDAAMediumBlueโ0x0000CDMediumOrchidโ0xBA55D3MediumPurpleโ0x9370D8MediumSeaGreenโ0x3CB371MediumSlateBlueโ0x7B68EEMediumSpringGreenโ0x00FA9AMediumTurquoiseโ0x48D1CCMediumVioletRedโ0xC71585MidnightBlueโ0x191970MintCreamโ0xF5FFFAMistyRoseโ0xFFE4E1Moccasinโ0xFFE4B5NavajoWhiteโ0xFFDEADNavyโ0x000080OldLaceโ0xFDF5E6Oliveโ0x808000OliveDrabโ0x6B8E23Orangeโ0xFFA500OrangeRedโ0xFF4500Orchidโ0xDA70D6PaleGoldenRodโ0xEEE8AAPaleGreenโ0x98FB98PaleTurquoiseโ0xAFEEEEPaleVioletRedโ0xD87093PapayaWhipโ0xFFEFD5PeachPuffโ0xFFDAB9Peruโ0xCD853FPinkโ0xFFC0CBPlumโ0xDDA0DDPowderBlueโ0xB0E0E6Purpleโ0x800080Redโ0xFF0000RosyBrownโ0xBC8F8FRoyalBlueโ0x4169E1SaddleBrownโ0x8B4513Salmonโ0xFA8072SandyBrownโ0xF4A460SeaGreenโ0x2E8B57SeaShellโ0xFFF5EESiennaโ0xA0522DSilverโ0xC0C0C0SkyBlueโ0x87CEEBSlateBlueโ0x6A5ACDSlateGrayโ0x708090Snowโ0xFFFAFASpringGreenโ0x00FF7FSteelBlueโ0x4682B4Tanโ0xD2B48CTealโ0x008080Thistleโ0xD8BFD8Tomatoโ0xFF6347Turquoiseโ0x40E0D0Violetโ0xEE82EEWheatโ0xF5DEB3Whiteโ0xFFFFFFWhiteSmokeโ0xF5F5F5Yellowโ0xFFFF00YellowGreenโ0x9ACD32
๐ Channel Layout ๐
A channel layout specifies the spatial disposition of the channels in a multi-channel audio stream. To specify a channel layout, FFmpeg makes use of a special syntax.
Individual channels are identified by an id, as given by the table below:
FLโ front leftFRโ front rightFCโ front centerLFEโ low frequencyBLโ back leftBRโ back rightFLCโ front left-of-centerFRCโ front right-of-centerBCโ back centerSLโ side leftSRโ side rightTCโ top centerTFLโ top front leftTFCโ top front centerTFRโ top front rightTBLโ top back leftTBCโ top back centerTBRโ top back rightDLโ downmix leftDRโ downmix rightWLโ wide leftWRโ wide rightSDLโ surround direct leftSDRโ surround direct rightLFE2โ low frequency 2
Standard channel layout compositions can be specified by using the following identifiers:
monoโFCstereoโFL+FR2.1โFL+FR+LFE3.0โFL+FR+FC3.0(back)โFL+FR+BC4.0โFL+FR+FC+BCquadโFL+FR+BL+BRquad(side)โFL+FR+SL+SR3.1โFL+FR+FC+LFE5.0โFL+FR+FC+BL+BR5.0(side)โFL+FR+FC+SL+SR4.1โFL+FR+FC+LFE+BC5.1โFL+FR+FC+LFE+BL+BR5.1(side)โFL+FR+FC+LFE+SL+SR6.0โFL+FR+FC+BC+SL+SR6.0(front)โFL+FR+FLC+FRC+SL+SR3.1.2โFL+FR+FC+LFE+TFL+TFRhexagonalโFL+FR+FC+BL+BR+BC6.1โFL+FR+FC+LFE+BC+SL+SR6.1โFL+FR+FC+LFE+BL+BR+BC6.1(front)โFL+FR+LFE+FLC+FRC+SL+SR7.0โFL+FR+FC+BL+BR+SL+SR7.0(front)โFL+FR+FC+FLC+FRC+SL+SR7.1โFL+FR+FC+LFE+BL+BR+SL+SR7.1(wide)โFL+FR+FC+LFE+BL+BR+FLC+FRC7.1(wide-side)โFL+FR+FC+LFE+FLC+FRC+SL+SR5.1.2โFL+FR+FC+LFE+BL+BR+TFL+TFRoctagonalโFL+FR+FC+BL+BR+BC+SL+SRcubeโFL+FR+BL+BR+TFL+TFR+TBL+TBR5.1.4โFL+FR+FC+LFE+BL+BR+TFL+TFR+TBL+TBR7.1.2โFL+FR+FC+LFE+BL+BR+SL+SR+TFL+TFR7.1.4โFL+FR+FC+LFE+BL+BR+SL+SR+TFL+TFR+TBL+TBR7.2.3โFL+FR+FC+LFE+BL+BR+SL+SR+TFL+TFR+TBC+LFE29.1.4โFL+FR+FC+LFE+BL+BR+FLC+FRC+SL+SR+TFL+TFR+TBL+TBR9.1.6โFL+FR+FC+LFE+BL+BR+FLC+FRC+SL+SR+TFL+TFR+TBL+TBR+TSL+TSRhexadecagonalโFL+FR+FC+BL+BR+BC+SL+SR+WL+WR+TBL+TBR+TBC+TFC+TFL+TFRbinauralโBIL+BIRdownmixโDL+DR22.2โFL+FR+FC+LFE+BL+BR+FLC+FRC+BC+SL+SR+TC+TFL+TFC+TFR+TBL+TBC+TBR+LFE2+TSL+TSR+BFC+BFL+BFR
A custom channel layout can be specified as a sequence of terms, separated by +. Each term can be:
- the name of a single channel (e.g.
FL,FR,FC,LFE, etc.), each optionally containing a custom name after a@, (e.g.FL@Left,FR@Right,FC@Center,LFE@Low_Frequency, etc.)
A standard channel layout can be specified by the following:
- the name of a single channel (e.g.
FL,FR,FC,LFE, etc.) - the name of a standard channel layout (e.g.
mono,stereo,4.0,quad,5.0, etc.) - a number of channels, in decimal, followed by
c, yielding the default channel layout for that number of channels (see the functionav_channel_layout_default). Note that not all channel counts have a default layout. - a number of channels, in decimal, followed by
C, yielding an unknown channel layout with the specified number of channels. Note that not all channel layout specification strings support unknown channel layouts. - a channel layout mask, in hexadecimal starting with
0x(see theAV_CH_*macros inlibavutil/channel_layout.h.)
Before libavutil version 53 the trailing character c to specify a number of channels was optional, but now it is required, while a channel layout mask can also be specified as a decimal number (if and only if not followed by c or C).
See also the function av_channel_layout_from_string defined in libavutil/channel_layout.h.
โจ EXPRESSION EVALUATION โจ
Okay bestie, when FFmpeg has to evaluate an arithmetic expression it uses an internal formula evaluator, and that evaluator is implemented through the libavutil/eval.h interface. ๐
An expression may contain unary operators, binary operators, constants, and functions.
Two expressions expr1 and expr2 can be combined into another expression expr1;expr2. They get evaluated one after the other, and the new expression evaluates to the value of expr2.
The binary operators you can use are: +, -, *, /, ^.
The unary operators you can use are: +, -.
Some internal variables can store and load intermediary results. You access them with the ld and st functions, using an index argument from 0 to 9 to pick which internal variable you mean. ๐
The following functions are available:
abs(x)โ compute the absolute value ofx.acos(x)โ compute the arccosine ofx.asin(x)โ compute the arcsine ofx.atan(x)โ compute the arctangent ofx.atan2(y, x)โ compute the principal value of the arc tangent ofy/x.between(x, min, max)โ return1ifxis greater than or equal tominand lesser than or equal tomax,0otherwise.bitand(x, y),bitor(x, y)โ compute the bitwise and/or operation onxandy. The results of evaluatingxandyare converted to integers before the bitwise operation. Note that both the conversion to integer and the conversion back to floating point can lose precision. Beware of unexpected results for large numbers, usually2^53and larger. ๐ceil(expr)โ round the value of expressionexprupwards to the nearest integer. For example,ceil(1.5)is2.0.clip(x, min, max)โ return the value ofxclipped betweenminandmax.cos(x)โ compute the cosine ofx.cosh(x)โ compute the hyperbolic cosine ofx.eq(x, y)โ return1ifxandyare equivalent,0otherwise.exp(x)โ compute the exponential ofxwith basee, the Euler's number.floor(expr)โ round the value of expressionexprdownwards to the nearest integer. For example,floor(-1.5)is-2.0.gauss(x)โ compute the Gauss function ofx, corresponding toexp(-x*x/2) / sqrt(2*PI).gcd(x, y)โ return the greatest common divisor ofxandy. If bothxandyare0, or either or both are less than zero, then behavior is undefined. ๐จgt(x, y)โ return1ifxis greater thany,0otherwise.gte(x, y)โ return1ifxis greater than or equal toy,0otherwise.hypot(x, y)โ similar to the C function with the same name; it returnssqrt(x*x + y*y), the length of the hypotenuse of a right triangle with sides of lengthxandy, or the distance of the point(x, y)from the origin.if(x, y)โ evaluatex, and if the result is non-zero return the result of the evaluation ofy, return0otherwise.if(x, y, z)โ evaluatex, and if the result is non-zero return the evaluation result ofy, otherwise the evaluation result ofz.ifnot(x, y)โ evaluatex, and if the result is zero return the result of the evaluation ofy, return0otherwise.ifnot(x, y, z)โ evaluatex, and if the result is zero return the evaluation result ofy, otherwise the evaluation result ofz.isinf(x)โ return1.0ifxis+/-INFINITY,0.0otherwise.isnan(x)โ return1.0ifxisNAN,0.0otherwise.ld(idx)โ load the value of the internal variable with indexidx, which was previously stored withst(idx, expr). The function returns the loaded value.lerp(x, y, z)โ return linear interpolation betweenxandyby amount ofz.log(x)โ compute the natural logarithm ofx.lt(x, y)โ return1ifxis lesser thany,0otherwise.lte(x, y)โ return1ifxis lesser than or equal toy,0otherwise.max(x, y)โ return the maximum betweenxandy.min(x, y)โ return the minimum betweenxandy.mod(x, y)โ compute the remainder of division ofxbyy.not(expr)โ return1.0ifexpris zero,0.0otherwise.pow(x, y)โ compute the power ofxelevatedy; it is equivalent to(x)^(y).print(t),print(t, l)โ print the value of expressiontwith loglevell. Iflis not specified then a default log level is used. Return the value of the expression printed.random(idx)โ return a pseudo random value between0.0and1.0.idxis the index of the internal variable used to save the seed/state, which can be previously stored withst(idx). To initialize the seed, you need to store the seed value as a 64-bit unsigned integer in the internal variable with indexidx. For example, to store the seed with value42in the internal variable with index0and print a few random values:
st(0,42); print(random(0)); print(random(0)); print(random(0))
randomi(idx, min, max)โ return a pseudo random value in the interval betweenminandmax.idxis the index of the internal variable which will be used to save the seed/state, which can be previously stored withst(idx). To initialize the seed, you need to store the seed value as a 64-bit unsigned integer in the internal variable with indexidx.root(expr, max)โ find an input value for which the function represented byexprwith argumentld(0)is0in the interval0..max. The expression inexprmust denote a continuous function or the result is undefined.ld(0)is used to represent the function input value, which means that the given expression will be evaluated multiple times with various input values that the expression can access throughld(0). When the expression evaluates to0then the corresponding input value will be returned.round(expr)โ round the value of expressionexprto the nearest integer. For example,round(1.5)is2.0.sgn(x)โ compute the sign ofx.sin(x)โ compute the sine ofx.sinh(x)โ compute the hyperbolic sine ofx.sqrt(expr)โ compute the square root ofexpr. This is equivalent to(expr)^.5.squish(x)โ compute the expression1/(1 + exp(4*x)).st(idx, expr)โ store the value of the expressionexprin an internal variable.idxspecifies the index of the variable where to store the value, and it is a value ranging from0to9. The function returns the value stored in the internal variable. The stored value can be retrieved withld(var). Note: variables are currently not shared between expressions.tan(x)โ compute the tangent ofx.tanh(x)โ compute the hyperbolic tangent ofx.taylor(expr, x),taylor(expr, x, idx)โ evaluate a Taylor series atx, given an expression representing theld(idx)-th derivative of a function at0. When the series does not converge the result is undefined.ld(idx)is used to represent the derivative order inexpr, which means that the given expression will be evaluated multiple times with various input values that the expression can access throughld(idx). Ifidxis not specified then0is assumed. Note, when you have the derivatives atyinstead of0,taylor(expr, x-y)can be used.time(0)โ return the current (wallclock) time in seconds.trunc(expr)โ round the value of expressionexprtowards zero to the nearest integer. For example,trunc(-1.5)is-1.0.while(cond, expr)โ evaluate expressionexprwhile the expressioncondis non-zero, and return the value of the lastexprevaluation, orNANifcondwas always false.
The following constants are available:
PIโ area of the unit disc, approximately3.14.Eโexp(1)(Euler's number), approximately2.718.PHIโ golden ratio(1+sqrt(5))/2, approximately1.618.
Assuming that an expression is considered "true" if it has a non-zero value, note that:
*works like AND.+works like OR.
For example, the construct:
if (A AND B) then C
is equivalent to:
if(A*B, C)
In your C code, you can extend the list of unary and binary functions, and define recognized constants, so that they are available for your expressions.
The evaluator also recognizes the International System unit prefixes. If 'i' is appended after the prefix, binary prefixes are used, which are based on powers of 1024 instead of powers of 1000. The 'B' postfix multiplies the value by 8, and can be appended after a unit prefix or used alone. This allows using, for example, 'KB', 'MiB', 'G' and 'B' as number postfix. ๐
The list of available International System prefixes follows, with indication of the corresponding powers of 10 and of 2.
yโ10^-24 / 2^-80zโ10^-21 / 2^-70aโ10^-18 / 2^-60fโ10^-15 / 2^-50pโ10^-12 / 2^-40nโ10^-9 / 2^-30uโ10^-6 / 2^-20mโ10^-3 / 2^-10cโ10^-2dโ10^-1hโ10^2kโ10^3 / 2^10Kโ10^3 / 2^10Mโ10^6 / 2^20Gโ10^9 / 2^30Tโ10^12 / 2^40Pโ10^15 / 2^50Eโ10^18 / 2^60Zโ10^21 / 2^70Yโ10^24 / 2^80
๐๏ธ CODEC OPTIONS ๐๏ธ
libavcodec provides some generic global options, which can be set on all the encoders and decoders. In addition, each codec may support so-called private options, which are specific for a given codec. ๐
Sometimes a global option may only affect a specific kind of codec, and may be nonsensical or ignored by another, so you need to be aware of the meaning of the specified options. Also some options are meant only for decoding or encoding.
Options may be set by specifying -option value in the FFmpeg tools, or by setting the value explicitly in the AVCodecContext options or using the libavutil/opt.h API for programmatic use.
The list of supported options follows:
binteger (encoding,audio,video) โ set bitrate in bits/s. Default value is200K.abinteger (encoding,audio) โ set audio bitrate in bits/s. Default value is128K.btinteger (encoding,video) โ set video bitrate tolerance in bits/s. In 1-pass mode, bitrate tolerance specifies how far ratecontrol is willing to deviate from the target average bitrate value. This is not related to min/max bitrate. Lowering tolerance too much has an adverse effect on quality.flagsflags (decoding/encoding,audio,video,subtitles) โ set generic flags.
Possible values:
mv4โ use four motion vector by macroblock (mpeg4).qpelโ use 1/4 pel motion compensation.
loopโ use the loop filter ๐qscaleโ use fixed qscale, periodt.pass1โ use internal 2pass ratecontrol in first pass mode.pass2โ use internal 2pass ratecontrol in second pass mode.grayโ only decode/encode grayscale, so no color for you bestie ๐ฉถpsnrโ seterror[?]variables during encoding.truncatedโ input bitstream might be randomly truncated ๐drop_changedโ don't output frames whose parameters differ from the first decoded frame in the stream. The errorAVERROR_INPUT_CHANGEDis returned when a frame is dropped.ildctโ use interlaced DCT.low_delayโ force low delay โกglobal_headerโ place global headers in extradata instead of every keyframe.bitexactโ only write platform-, build- and time-independent data (except (I)DCT). This ensures that file and data checksums are reproducible and match between platforms. Its primary use is for regression testing, iykyk ๐งชaicโ apply H263 advanced intra coding / mpeg4 ac prediction.ilmeโ apply interlaced motion estimation.cgopโ use closed gop.output_corruptโ output even potentially corrupted frames ๐
time_base(rational number) โ set codec time base.
It's the fundamental unit of time (in seconds) that frame timestamps get represented in terms of. For fixed-fps content, timebase should be 1 / frame_rate and timestamp increments should be identically 1.
g(integer, encoding,video) โ set the group of picture (GOP) size. Default value is12.ar(integer, decoding/encoding,audio) โ set audio sampling rate (in Hz).ac(integer, decoding/encoding,audio) โ set number of audio channels.cutoff(integer, encoding,audio) โ set cutoff bandwidth. (Supported only by selected encoders, see their respective documentation sections, fr.)frame_size(integer, encoding,audio) โ set audio frame size.
Every submitted frame except the last one must contain exactly frame_size samples per channel. It may be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set โ in that case the frame size is not restricted. Some decoders set it to indicate a constant frame size.
frame_number(integer) โ set the frame number.delay(integer) โ the delay, bestie.qcomp(float, encoding,video) โ set video quantizer scale compression (VBR). It's used as a constant in the ratecontrol equation. Recommended range for defaultrc_eq:0.0-1.0.qblur(float, encoding,video) โ set video quantizer scale blur (VBR).qmin(integer, encoding,video) โ set min video quantizer scale (VBR). Must be included between-1and69, default value is2.qmax(integer, encoding,video) โ set max video quantizer scale (VBR). Must be included between-1and1024, default value is31.qdiff(integer, encoding,video) โ set max difference between the quantizer scale (VBR).bf(integer, encoding,video) โ set max number of B frames between non-B-frames.
Must be an integer between -1 and 16. 0 means B-frames are disabled. If you use -1, it'll pick an automatic value depending on the encoder.
Default value is 0.
b_qfactor(float, encoding,video) โ set qp factor between P and B frames.codec_tag(integer) โ the codec tag.bug(flags, decoding,video) โ workaround for encoder bugs that aren't auto detected ๐
Possible values:
autodetectxvid_ilaceโ Xvid interlacing bug (autodetected iffourcc==XVIX)ump4โ (autodetected iffourcc==UMP4)no_paddingโ padding bug (autodetected)amvqpel_chromastd_qpelโ old standard qpel (autodetected per fourcc/version)qpel_chroma2direct_blocksizeโ direct-qpel-blocksize bug (autodetected per fourcc/version)edgeโ edge padding bug (autodetected per fourcc/version)hpel_chromadc_clipmsโ workaround various bugs in microsoft broken decoders ๐truncโ trancated frames
strict(integer, decoding/encoding,audio,video) โ specify how strictly to follow the standards.
Possible values:
veryโ strictly conform to an older more strict version of the spec or reference softwarestrictโ strictly conform to all the things in the spec no matter what consequencesnormalunofficialโ allow unofficial extensionsexperimentalโ allow non standardized experimental things, experimental (unfinished/work in progress/not well tested) decoders and encoders.
Note: experimental decoders can pose a security risk โ do not use this for decoding untrusted input. Like, genuinely bestie, don't ๐ฅ
b_qoffset(float, encoding,video) โ set QP offset between P and B frames.err_detect(flags, decoding,audio,video) โ set error detection flags.
Possible values:
crccheckโ verify embedded CRCsbitstreamโ detect bitstream specification deviationsbufferโ detect improper bitstream lengthexplodeโ abort decoding on minor error detection ๐ฅignore_errโ ignore decoding errors, and continue decoding. This is useful if you want to analyze the content of a video and thus want everything to be decoded no matter what. This option will not result in a video that is pleasing to watch in case of errors, ngl.carefulโ consider things that violate the spec and have not been seen in the wild as errorscompliantโ consider all spec non compliancies as errorsaggressiveโ consider things that a sane encoder should not do as an error
has_b_frames(integer) โ whether it has B frames.block_align(integer) โ the block align.rc_override_count(integer) โ the rc override count.maxrate(integer, encoding,audio,video) โ set max bitrate tolerance (in bits/s). Requiresbufsizeto be set.minrate(integer, encoding,audio,video) โ set min bitrate tolerance (in bits/s). Most useful in setting up a CBR encode. It's of little use elsewise.bufsize(integer, encoding,audio,video) โ set ratecontrol buffer size (in bits).i_qfactor(float, encoding,video) โ set QP factor between P and I frames.i_qoffset(float, encoding,video) โ set QP offset between P and I frames.dct(integer, encoding,video) โ set DCT algorithm.
Possible values:
autoโ autoselect a good one (default)fastintโ fast integerintโ accurate integermmxaltivecfaanโ floating point AAN DCT
lumi_mask(float, encoding,video) โ compress bright areas stronger than medium ones โจtcplx_mask(float, encoding,video) โ set temporal complexity masking.scplx_mask(float, encoding,video) โ set spatial complexity masking.p_mask(float, encoding,video) โ set inter masking.dark_mask(float, encoding,video) โ compress dark areas stronger than medium ones ๐idct(integer, decoding/encoding,video) โ select IDCT implementation.
Possible values:
autointsimplesimplemmxsimpleautoโ automatically pick a IDCT compatible with the simple onearmaltivecsh4simplearmsimplearmv5tesimplearmv6simpleneonxvidfaaniโ floating point AAN IDCT
slice_count(integer) โ the slice count.ec(flags, decoding,video) โ set error concealment strategy.
Possible values:
guess_mvsโ iterative motion vector (MV) search (slow) ๐deblockโ use strong deblock filter for damaged MBsfavor_interโ favor predicting from the previous frame instead of the current
bits_per_coded_sample(integer) โ the bits per coded sample.aspect(rational number, encoding,video) โ set sample aspect ratio.sar(rational number, encoding,video) โ set sample aspect ratio. Alias toaspect.debug(flags, decoding/encoding,audio,video,subtitles) โ print specific debug info.
Possible values:
pictโ picture inforcโ rate controlbitstreammb_typeโ macroblock (MB) typeqpโ per-block quantization parameter (QP)dct_coeffgreen_metadataโ display complexity metadata for the upcoming frame, GoP or for a given duration.skipstartcodeerโ error recognitionmmcoโ memory management control operations (H.264)bugsbuffersโ picture buffer allocationsthread_opsโ threading operationsnomcโ skip motion compensation
cmp(integer, encoding,video) โ set full pel me compare function.
Possible values:
sadโ sum of absolute differences, fast (default)sseโ sum of squared errorssatdโ sum of absolute Hadamard transformed differencesdctโ sum of absolute DCT transformed differencespsnrโ sum of squared quantization errors (avoid, low quality)bitโ number of bits needed for the blockrdโ rate distortion optimal, slowzeroโ0vsadโ sum of absolute vertical differencesvsseโ sum of squared vertical differencesnsseโ noise preserving sum of squared differencesw53โ 5/3 wavelet, only used in snoww97โ 9/7 wavelet, only used in snowdctmaxchroma
subcmp(integer, encoding,video) โ set sub pel me compare function.
Possible values:
sadโ sum of absolute differences, fast (default)sseโ sum of squared errorssatdโ sum of absolute Hadamard transformed differencesdctโ sum of absolute DCT transformed differencespsnrโ sum of squared quantization errors (avoid, low quality)bitโ number of bits needed for the blockrdโ rate distortion optimal, slowzeroโ0vsadโ sum of absolute vertical differencesvsseโ sum of squared vertical differencesnsseโ noise preserving sum of squared differencesw53โ 5/3 wavelet, only used in snoww97โ 9/7 wavelet, only used in snowdctmaxchroma
mbcmp(integer, encoding,video) โ set macroblock compare function.
Possible values:
okay continuing the compare-function menu, no cap โ here's the whole value lineup:
sadโ sum of absolute differences, fast (default) โกsseโ sum of squared errorssatdโ sum of absolute Hadamard transformed differencesdctโ sum of absolute DCT transformed differencespsnrโ sum of squared quantization errors (avoid, low quality) ๐ฌbitโ number of bits needed for the blockrdโ rate distortion optimal, slow ๐ขzeroโ 0vsadโ sum of absolute vertical differencesvsseโ sum of squared vertical differencesnsseโ noise preserving sum of squared differencesw53โ 5/3 wavelet, only used in snoww97โ 9/7 wavelet, only used in snowdctmaxchroma
ildctcmpinteger (encoding,video) โ Set interlaced dct compare function. ๐งต- Possible values:
sadโ sum of absolute differences, fast (default)sseโ sum of squared errorssatdโ sum of absolute Hadamard transformed differencesdctโ sum of absolute DCT transformed differencespsnrโ sum of squared quantization errors (avoid, low quality)bitโ number of bits needed for the blockrdโ rate distortion optimal, slowzeroโ 0vsadโ sum of absolute vertical differencesvsseโ sum of squared vertical differencesnsseโ noise preserving sum of squared differencesw53โ 5/3 wavelet, only used in snoww97โ 9/7 wavelet, only used in snowdctmaxchroma
- Possible values:
dia_sizeinteger (encoding,video) โ Set diamond type & size for motion estimation. ๐(1024, INT_MAX)โ full motion estimation(slowest)(768, 1024]โ umh motion estimation(512, 768]โ hex motion estimation(256, 512]โ l2s diamond motion estimation[2,256]โ var diamond motion estimation(-1, 2)โ small diamond motion estimation-1โ funny diamond motion estimation ๐ญ(INT_MIN, -1)โ sab diamond motion estimation
last_predinteger (encoding,video) โ Set amount of motion predictors from the previous frame.precmpinteger (encoding,video) โ Set pre motion estimation compare function. ๐- Possible values:
sadโ sum of absolute differences, fast (default)sseโ sum of squared errorssatdโ sum of absolute Hadamard transformed differencesdctโ sum of absolute DCT transformed differencespsnrโ sum of squared quantization errors (avoid, low quality)bitโ number of bits needed for the blockrdโ rate distortion optimal, slowzeroโ 0vsadโ sum of absolute vertical differencesvsseโ sum of squared vertical differencesnsseโ noise preserving sum of squared differencesw53โ 5/3 wavelet, only used in snoww97โ 9/7 wavelet, only used in snowdctmaxchroma
- Possible values:
pre_dia_sizeinteger (encoding,video) โ Set diamond type & size for motion estimation pre-pass.subqinteger (encoding,video) โ Set sub pel motion estimation quality.me_rangeinteger (encoding,video) โ Set limit motion vectors range (1023 for DivX player).global_qualityinteger (encoding,audio,video)slice_flagsintegermbdinteger (encoding,video) โ Set macroblock decision algorithm (high quality mode). ๐ง- Possible values:
simpleโ usembcmp(default)bitsโ use fewest bitsrdโ use best rate distortion
- Possible values:
rc_init_occupancyinteger (encoding,video) โ Set number of bits which should be loaded into the rc buffer before decoding starts.flags2flags (decoding/encoding,audio,video,subtitles) โ Possible values:fastโ Allow non spec compliant speedup tricks.nooutโ Skip bitstream encoding.ignorecropโ Ignore cropping information from sps.local_headerโ Place global headers at every keyframe instead of in extradata.chunksโ Frame data might be split into multiple chunks.showallโ Show all frames before the first keyframe.export_mvsโ Export motion vectors into frame side-data (seeAV_FRAME_DATA_MOTION_VECTORS) for codecs that support it. See alsodoc/examples/export_mvs.c.skip_manualโ Do not skip samples and export skip information as frame side data.ass_ro_flush_noopโ Do not reset ASS ReadOrder field on flush.icc_profilesโ Generate/parse embedded ICC profiles from/to colorimetry tags.
export_side_dataflags (decoding/encoding,audio,video,subtitles) โ Possible values:mvsโ Export motion vectors into frame side-data (seeAV_FRAME_DATA_MOTION_VECTORS) for codecs that support it. See alsodoc/examples/export_mvs.c.prftโ Export encoder Producer Reference Time into packet side-data (seeAV_PKT_DATA_PRFT) for codecs that support it.venc_paramsโ Export video encoding parameters through frame side data (seeAV_FRAME_DATA_VIDEO_ENC_PARAMS) for codecs that support it. At present, those are H.264 and VP9.film_grainโ Export film grain parameters through frame side data (seeAV_FRAME_DATA_FILM_GRAIN_PARAMS). Supported at present by AV1 decoders.enhancementsโ Export picture enhancement metadata through frame side data, e.g. LCEVC (seeAV_FRAME_DATA_LCEVC).
threadsinteger (decoding/encoding,video) โ Set the number of threads to be used, in case the selected codec implementation supports multi-threading. ๐งต- Possible values:
auto,0โ automatically select the number of threads to set
- Default value is
auto.
- Possible values:
dcinteger (encoding,video) โ Setintra_dc_precision.nssewinteger (encoding,video) โ Set nsse weight.skip_topinteger (decoding,video) โ Set number of macroblock rows at the top which are skipped.skip_bottominteger (decoding,video) โ Set number of macroblock rows at the bottom which are skipped.profileinteger (encoding,audio,video) โ Set encoder codec profile. Default value is unknown. Encoder specific profiles are documented in the relevant encoder documentation.levelinteger (encoding,audio,video) โ Set the encoder level. This level depends on the specific codec, and might correspond to the profile level. It is set by default to unknown.- Possible values:
unknown
- Possible values:
lowresinteger (decoding,audio,video) โ Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.mblmininteger (encoding,video) โ Set min macroblock lagrange factor (VBR).mblmaxinteger (encoding,video) โ Set max macroblock lagrange factor (VBR).skip_loop_filter,skip_idct,skip_frameโ integer (decoding,video). Make decoder discard processing depending on the frame type selected by the option value.skip_loop_filterskips frame loop filtering,skip_idctskips frame IDCT/dequantization,skip_frameskips decoding.- Possible values:
noneโ Discard no frame.defaultโ Discard useless frames like 0-sized frames.norefโ Discard all non-reference frames.bidirโ Discard all bidirectional frames.nokeyโ Discard all frames excepts keyframes.nointraโ Discard all frames except I frames.allโ Discard all frames.
- Default value is
default.
bidir_refineinteger (encoding,video) โ Refine the two motion vectors used in bidirectional macroblocks.keyint_mininteger (encoding,video) โ Set minimum interval between IDR-frames.refsinteger (encoding,video) โ Set reference frames to consider for motion compensation.trellisinteger (encoding,audio,video) โ Set rate-distortion optimal quantization.mv0_thresholdinteger (encoding,video)compression_levelinteger (encoding,audio,video)bits_per_raw_sampleintegerchannel_layoutinteger (decoding/encoding,audio) โ See the Channel Layout section in theffmpeg-utils(1)manual for the required syntax.rc_max_vbv_usefloat (encoding,video)rc_min_vbv_usefloat (encoding,video)color_primariesinteger (decoding/encoding,video) โ Possible values:bt709โ BT.709bt470mโ BT.470 Mbt470bgโ BT.470 BGsmpte170mโ SMPTE 170 Msmpte240mโ SMPTE 240 Mfilmโ Filmbt2020โ BT.2020smpte428,smpte428_1โ SMPTE ST 428-1smpte431โ SMPTE 431-2smpte432โ SMPTE 432-1jedec-p22โ JEDEC P22
color_trcinteger (decoding/encoding,video) โ Possible values:bt709โ BT.709gamma22โ BT.470 Mgamma28โ BT.470 BGsmpte170mโ SMPTE 170 Msmpte240mโ SMPTE 240 Mlinearโ Linearlog,log100โ Loglog_sqrt,log316โ Log square rootiec61966_2_4,iec61966-2-4โ IEC 61966-2-4bt1361,bt1361eโ BT.1361iec61966_2_1,iec61966-2-1โ IEC 61966-2-1bt2020_10,bt2020_10bitโ BT.2020 - 10 bitbt2020_12,bt2020_12bitโ BT.2020 - 12 bitsmpte2084โ SMPTE ST 2084smpte428,smpte428_1โ SMPTE ST 428-1arib-std-b67โ ARIB STD-B67
colorspaceinteger (decoding/encoding,video) โ Possible values:rgbโ RGBbt709โ BT.709fccโ FCCbt470bgโ BT.470 BGsmpte170mโ SMPTE 170 Msmpte240mโ SMPTE 240 Mycocgโ YCOCGbt2020nc,bt2020_nclโ BT.2020 NCLbt2020c,bt2020_clโ BT.2020 CLsmpte2085โ SMPTE 2085chroma-derived-ncโ Chroma-derived NCLchroma-derived-cโ Chroma-derived CLictcpโ ICtCp
color_rangeinteger (decoding/encoding, video) โ when you use this as an input parameter it's basically a lil hint to the decoder like "hey bestie, here's thecolor_rangethe input is serving". Possible values:tvmpeglimitedโ MPEG (219*2^(n-8))pcjpegfullโ JPEG (2^n-1)
chroma_sample_locationinteger (decoding/encoding, video) โ where the chroma is at, location-wise. Possible values:leftcentertoplefttopbottomleftbottom
alpha_modeinteger (decoding/encoding, video) โ the alpha vibe. Possible values:premultipliedstraight
log_level_offsetinteger โ sets the log level offset. that's it, that's the whole thing ๐slicesinteger (encoding, video) โ how many slices you want, used in parallelized encoding. more slices = more parallel besties doing the work.thread_typeflags (decoding/encoding, video) โ picks which multithreading methods get used. no cap.
using frame will increase decoding delay by one frame per thread, so clients that literally cannot provide future frames should not use it. read that again, it matters ๐ญ
Possible values:
sliceโ decode more than one part of a single frame at once. multithreading with slices only works when the video was encoded with slices, iykyk.frameโ decode more than one frame at once.
Default value is slice+frame. iconic default, honestly.
audio_service_typeinteger (encoding, audio) โ sets the audio service type. Possible values:maโ Main Audio Serviceefโ Effectsviโ Visually Impairedhiโ Hearing Impaireddiโ Dialoguecoโ Commentaryemโ Emergencyvoโ Voice Overkaโ Karaoke
request_sample_fmtsample_fmt (decoding, audio) โ sets the sample format audio decoders should prefer. Default value is"none". manifesting a sample format for u โจpkt_timebaserational number โ the timebase for packets. look at it. it's a rational number. that's the whole description, she's concise today ๐sub_charencencoding (decoding, subtitles) โ sets the input subtitles character encoding. so ur subs don't come out looking like mojibake ๐field_orderfield_order (video) โ sets/overrides the field order of the video. Possible values:progressiveโ Progressive videottโ Interlaced video, top field coded and displayed firstbbโ Interlaced video, bottom field coded and displayed firsttbโ Interlaced video, top coded first, bottom displayed firstbtโ Interlaced video, bottom coded first, top displayed first
skip_alphabool (decoding, video) โ set to1to disable processing alpha (transparency). this works like thegrayflag in theflagsoption, which skips chroma information instead of alpha. Default is0.codec_whitelistlist (input) โ a","separated list of allowed decoders. by default all are allowed. the VIP list of decoders ๐dump_separatorstring (input) โ the separator used to separate the fields printed on the command line about the Stream parameters. for example, to separate the fields with newlines and indentation:
ffprobe -dump_separator "
" -i ~/videos/matrixbench_mpeg2.mpg
(yes the separator is literally a newline plus spaces. she contains multitudes.)
max_pixelsinteger (decoding/encoding, video) โ maximum number of pixels per image. you can use this value to avoid out of memory failures due to large images. protect ur RAM bestie ๐ซถapply_croppingbool (decoding, video) โ enables cropping if the cropping parameters are multiples of the required alignment for the left and top parameters. if the alignment is not met, the cropping will be partially applied to maintain alignment. Default is1(enabled).
Note: the required alignment depends on ifAV_CODEC_FLAG_UNALIGNEDis set and the CPU.AV_CODEC_FLAG_UNALIGNEDcannot be changed from the command line. also hardware decoders will not apply left/top Cropping. not them skipping the crop ๐ญ
๐ฌ DECODERS
Decoders are configured elements in FFmpeg that allow the decoding of multimedia streams. they're the ones turning ur mystery bytes back into actual video. main character energy, honestly.
When you configure your FFmpeg build, all the supported native decoders are enabled by default. decoders requiring an external library must be enabled manually via the corresponding --enable-lib option. you can list all available decoders using the configure option --list-decoders.
You can disable all the decoders with the configure option --disable-decoders and selectively enable / disable single decoders with the options --enable-decoder=DECODER / --disable-decoder=DECODER.
The option -decoders of the ff* tools will display the list of enabled decoders.
๐ฅ VIDEO DECODERS
A description of some of the currently available video decoders follows. buckle up bestie ๐
av1
AOMedia Video 1 (AV1) decoder. she's everywhere now and she ate.
Options
operating_pointโ select an operating point of a scalable AV1 bitstream (0-31). Default is0.
hevc
HEVC (AKA ITU-T H.265 or ISO/IEC 23008-2) decoder. yes it has three names, it's that girl.
The decoder supports MV-HEVC multiview streams with at most two views. Views to be output are selected by supplying a list of view IDs to the decoder (the view_ids option). This option may be set either statically before decoder init, or from the get_format() callback โ useful for the case when the view count or IDs change dynamically during decoding.
Only the base layer is decoded by default.
Note that if you are using the ffmpeg CLI tool, you should be using view specifiers as documented in its manual, rather than the options documented here. like, read the other manual, bestie, this one's not it for that ๐ธ
Options
view_ids(MV-HEVC) โ specify a list of view IDs that should be output. this option can also be set to a single-1, which will cause all views defined in the VPS to be decoded and output.view_ids_available(MV-HEVC) โ this option may be read by the caller to retrieve an array of view IDs available in the active VPS. the array is empty for single-layer video.
The value of this option is guaranteed to be accurate when read from the get_format() callback. It may also be set at other times (e.g. after opening the decoder), but the value is informational only and may be incorrect (e.g. when the stream contains multiple distinct VPS NALUs). so like... trust it, but only in the callback ๐
view_pos_available(MV-HEVC) โ this option may be read by the caller to retrieve an array of view positions (left, right, or unspecified) available in the active VPS, asAVStereo3DViewvalues. When the array is available, its elements apply to the corresponding elements ofview_ids_available, i.e.view_pos_available[i]contains the position of view with IDview_ids_available[i].
Same validity restrictions as for view_ids_available apply to this option. same rules, same caveats, no exceptions.
rawvideo
Raw video decoder. it decodes rawvideo streams. what did u expect. she's literally named after her job.
Options
toptop_field_first โ specify the assumed field type of the input video.-1โ the video is assumed to be progressive (default)0โ bottom-field-first is assumed1โ top-field-first is assumed
libdav1d
dav1d AV1 decoder. the fast one. the beloved one.
libdav1d allows libavcodec to decode the AOMedia Video 1 (AV1) codec. Requires the presence of the libdav1d headers and library during configuration. You need to explicitly configure the build with --enable-libdav1d.
Options
The following options are supported by the libdav1d wrapper.
max_frame_delayโ set max amount of frames the decoder may buffer internally. the default value is0(autodetect).filmgrainโ apply film grain to the decoded video if present in the bitstream. defaults to the internal default of the library.
this option is deprecated and will be removed in the future. see the global option export_side_data to export Film Grain parameters instead of applying it. like pls stop using it bestie, it's on the way out ๐
oppointโ select an operating point of a scalable AV1 bitstream (0-31). defaults to the internal default of the library.alllayersโ output all spatial layers of a scalable AV1 bitstream. the default value isfalse.
libdavs2
AVS2-P2/IEEE1857.4 video decoder wrapper.
This decoder allows libavcodec to decode AVS2 streams with davs2 library. that's the whole thing, she's a wrapper and she's proud ๐ฆ
libuavs3d
AVS3-P2/IEEE1857.10 video decoder.
libuavs3d allows libavcodec to decode AVS3 streams. Requires the presence of the libuavs3d headers and library during configuration. You need to explicitly configure the build with --enable-libuavs3d.
Options
The following option is supported by the libuavs3d wrapper.
frame_threadsโ set amount of frame threads to use during decoding. the default value is0(autodetect).
libxevd
eXtra-fast Essential Video Decoder (XEVD) MPEG-5 EVC decoder wrapper.
This decoder requires the presence of the libxevd headers and library during configuration. You need to explicitly configure the build with --enable-libxevd.
The xevd project website is at https://github.com/mpeg5/xevd.
Options
The following options are supported by the libxevd wrapper. The xevd-equivalent options or values are listed in parentheses for easy migration. thoughtful queen ๐
To get a more accurate and extensive documentation of the libxevd options, invoke the command xevd_app --help or consult the libxevd documentation.
threads(threads) โ force to use a specific number of threads. no autodetect, no vibes, just a number.
QSV Decoders
The family of Intel QuickSync Video decoders (VC1, MPEG-2, H.264, HEVC, JPEG/MJPEG, VP8, VP9, AV1, VVC). the whole squad, all invited to the party โญ
Common Options
The following options are supported by all qsv decoders.
async_depthโ internal parallelization depth, the higher the value the higher the latency. yes that's a tradeoff, no you can't have both, choose ur fighter.gpu_copyโ a GPU-accelerated copy between video and system memory. possible values:defaultonoff
HEVC Options
Extra options for hevc_qsv.
load_pluginโ a user plugin to load in an internal session.nonehevc_swhevc_hw
load_pluginsโ a:-separate list of hexadecimal plugin UIDs to load in an internal session.
v210
Uncompressed 4:2:2 10-bit decoder. no compression, just vibes and bits.
Options
custom_strideโ set the line size of the v210 data in bytes. the default value is0(autodetect). you can use the special-1value for a strideless v210 as seen in BOXX files. special little guy ๐
๐ถ AUDIO DECODERS ๐ถ
okay bestie, it's audio decoder time ๐ here's a description of some of the currently available audio decoders, and yes we're going through every single one like the responsible little Unix gremlin you are โจ
๐ง ac3 ๐ง
AC-3 audio decoder. iconic behavior honestly.
This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as the undocumented RealAudio 3 (a.k.a. dnet). no cap, it's doing both the documented and the mysterious ๐
๐๏ธ AC-3 Decoder Options ๐๏ธ
-drc_scale valueโ Dynamic Range Scale Factor. The factor to apply to dynamic range values from the AC-3 stream. This factor is applied exponentially. The default value is1. There are 3 notable scale factor ranges:drc_scale == 0โ DRC disabled. Produces full range audio.0 < drc_scale <= 1โ DRC enabled. Applies a fraction of the stream DRC value. Audio reproduction is between full range and full compression.drc_scale > 1โ DRC enabled. Appliesdrc_scaleasymmetrically. Loud sounds are fully compressed. Soft sounds are enhanced.
๐ธ flac ๐ธ
FLAC audio decoder. she's giving lossless main character energy ๐ฆ
This decoder aims to implement the complete FLAC specification from Xiph. periodt.
๐ FLAC Decoder options ๐
-use_buggy_lpcโ The lavc FLAC encoder used to produce buggy streams with highlpcvalues (like the default value). This option makes it possible to decode such streams correctly by using lavc's old buggylpclogic for decoding. it's literally a little time machine for buggy streams ๐ญ
๐ง ffwavesynth ๐ง
Internal wave synthesizer. very mysterious, very internal, very "don't worry about it" ๐
This decoder generates wave patterns according to predefined sequences. Its use is purely internal and the format of the data it accepts is not publicly documented. so yeah, private vibes only ๐
๐ฆ libcelt ๐ฆ
libcelt decoder wrapper.
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec. Requires the presence of the libcelt headers and library during configuration. You need to explicitly configure the build with --enable-libcelt. slay, but configure it first bestie โจ
๐ libgsm ๐
libgsm decoder wrapper.
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires the presence of the libgsm headers and library during configuration. You need to explicitly configure the build with --enable-libgsm.
This decoder supports both the ordinary GSM and the Microsoft variant. two flavors, one wrapper, we love a versatile icon ๐
๐ libilbc ๐
libilbc decoder wrapper.
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC) audio codec. Requires the presence of the libilbc headers and library during configuration. You need to explicitly configure the build with --enable-libilbc.
โจ Options โจ
The following option is supported by the libilbc wrapper.
enhanceโ Enable the enhancement of the decoded audio when set to1. The default value is0(disabled). so if you want the glow-up, set it to1๐ซถ
๐ libmpeghdec ๐
libmpeghdec decoder wrapper.
libmpeghdec allows libmpeghdec to decode the MPEG-H 3D audio codec. Requires the presence of the libmpeghdec headers and library during configuration. You need to explicitly configure the build with --enable-libmpeghdec --enable-nonfree. note the --enable-nonfree part, bestie, it's right there in the configure line ๐
๐ฅ libopencore-amrnb ๐ฅ
libopencore-amrnb decoder wrapper.
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate Narrowband audio codec. Using it requires the presence of the libopencore-amrnb headers and library during configuration. You need to explicitly configure the build with --enable-libopencore-amrnb.
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB without this library. so like, this wrapper is cute but not mandatory ๐
๐ libopencore-amrwb ๐
libopencore-amrwb decoder wrapper.
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate Wideband audio codec. Using it requires the presence of the libopencore-amrwb headers and library during configuration. You need to explicitly configure the build with --enable-libopencore-amrwb.
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB without this library. again: native option exists, no stress required ๐ธ
๐ libopus ๐
libopus decoder wrapper.
libopus allows libavcodec to decode the Opus Interactive Audio Codec. Requires the presence of the libopus headers and library during configuration. You need to explicitly configure the build with --enable-libopus.
An FFmpeg native decoder for Opus exists, so users can decode Opus without this library. iconic of FFmpeg to have a native fallback, honestly ๐
๐ SUBTITLES DECODERS ๐
These are the subtitle decoders, bestie โ the little guys that turn squiggly caption data into actual readable words on your screen. Let's go through them one by one, no cap.
๐ธ libaribb24
A caption decoder for ARIB STD-B24. It implements profiles A and C of the ARIB STD-B24 standard. That's it, that's the whole vibe.
โจ libaribb24 Decoder Options โจ
-aribb24-base-path pathโ sets the base path for the libaribb24 library. It's used for reading configuration files (for custom unicode conversions) and for dumping non-text symbols as images under that location. Unset by default โ so if you don't set it, nothing's set, periodt.-aribb24-skip-ruby-text booleanโ tells the decoder wrapper to skip text blocks that contain half-height ruby text. It's enabled by default โ so she's already skipping that for you, slay.
๐ฆ libaribcaption
Yet another ARIB STD-B24 caption decoder, this one leaning on the external libaribcaption library. It implements profiles A and C of the Japanese ARIB STD-B24 standard, plus Brazilian ABNT NBR 15606-1, plus the Philippines version of ISDB-T. Versatile icon.
It needs the libaribcaption headers and library (https://github.com/xqq/libaribcaption) present during configuration. You have to explicitly configure the build with "--enable-libaribcaption" โ it will not just show up. And listen: if both libaribb24 and libaribcaption are enabled, libaribcaption decoder precedes. She's the main character in that scenario, iykyk.
๐ libaribcaption Decoder Options ๐
-sub_type subtitle_typeโ specifies the format of the decoded subtitles:bitmapโ graphical image.assโ ASS formatted text.textโ simple text based output without formatting.
The default is ass, same as the libaribb24 decoder. Some present players (e.g., mpv) expect ASS format for ARIB caption. So the default is doing the work for you fr fr.
-caption_encoding encoding_schemeโ specifies the encoding scheme of input subtitle text:autoโ automatically detect text encoding (default).jisโ 8bit-char JIS encoding defined in ARIB STD B24. This encoding is used in Japan for ISDB captions.utf8โ UTF-8 encoding defined in ARIB STD B24. This encoding is used in Philippines for ISDB-T captions.latinโ Latin character encoding defined in ABNT NBR 15606-1. This encoding is used in South America for SBTVD / ISDB-Tb captions.
-font font_name[,font_name2,...]โ specify a comma-separated list of font family names to be used forbitmaporasstype subtitle rendering. Only the first font name is used forasstype subtitle. If not specified, it uses the internally defined default font family. ๐-ass_single_rect booleanโ okay so ARIB STD-B24 specifies that some captions may be displayed at different positions at a time (that's the multi-rectangle subtitle situation). Since some players (e.g., oldmpv) can't handle multiple ASS rectangles in a single AVSubtitle, or multiple ASS rectangles of indeterminate duration with the same start timestamp, this option can change the behavior so that all the texts are displayed in a single ASS rectangle. The default isfalse. If your player cannot handle AVSubtitles with multiple ASS rectangles properly, set this option totrueor defineASS_SINGLE_RECT=1to change default behavior at compilation. Fix it at build time or fix it at runtime, your call bestie.-force_outline_text booleanโ specify whether to always render outline text for all characters, regardless of the indication by character style. The default isfalse.-outline_width number (0.0 - 3.0)โ specify width for outline text, in dots (relative). The default is1.5.-ignore_background booleanโ specify whether to ignore background color rendering. The default isfalse.-ignore_ruby booleanโ specify whether to ignore rendering for ruby-like (furigana) characters. The default isfalse.-replace_drcs booleanโ specify whether to render replaced DRCS characters as Unicode characters. The default istrue.-replace_msz_ascii booleanโ specify whether to replace MSZ (Middle Size; half width) fullwidth alphanumerics with halfwidth alphanumerics. The default istrue.-replace_msz_japanese booleanโ specify whether to replace some MSZ (Middle Size; half width) fullwidth japanese special characters with halfwidth ones. The default istrue.-replace_msz_glyph booleanโ specify whether to replace MSZ (Middle Size; half width) characters with halfwidth glyphs if the font supports it. This option works under FreeType or DirectWrite renderer with Adobe-Japan1 compliant fonts โ e.g.,IBM Plex Sans JP,Morisawa BIZ UDGothic,Morisawa BIZ UDMincho,Yu Gothic,Yu Mincho, andMeiryo. The default istrue. Font-girlie behavior, honestly iconic.-canvas_size image_sizeโ specify the resolution of the canvas to render subtitles to; usually, this should be the frame size of the input video. This only applies when"-subtitle_type"is set tobitmap.
The libaribcaption decoder assumes input frame size for bitmap rendering as below:
PROFILE_A:1440 x 1080with SAR (PAR)4:3PROFILE_C:320 x 180with SAR (PAR)1:1
If the actual frame size of the input video does not match the above assumption, the rendered captions may be distorted. To make the captions undistorted, add the "-canvas_size" option to specify the actual input video size.
Note that the"-canvas_size"option is not required for video with a different size but the same aspect ratio. In such cases, the caption will be stretched or shrunk to the actual video size if the"-canvas_size"option is not specified. If the"-canvas_size"option is specified with a different size, the caption will be stretched or shrunk to the specified size with the calculated SAR. Math girlie eats. ๐ฅ
๐ libaribcaption decoder usage examples ๐
Display an MPEG-TS file with ARIB subtitle using the ffplay tool:
ffplay -sub_type bitmap MPEG.TS
Display an MPEG-TS file with input frame size 1920x1080 using the ffplay tool:
ffplay -sub_type bitmap -canvas_size 1920x1080 MPEG.TS
Embed ARIB subtitle in transcoded video:
ffmpeg -sub_type bitmap -i src.m2t -filter_complex "[0:v][0:s]overlay" -vcodec h264 dest.mp4
โญ dvbsub
Options
compute_clut-2โ compute CLUT once if no matching CLUT is in the stream.-1โ compute CLUT if no matching CLUT is in the stream.0โ never compute CLUT.1โ always compute CLUT and override the one provided in the stream. She's not asking, she's taking over. ๐
dvb_substreamโ selects the dvb substream, or all substreams if-1, which is the default.
๐ dvdsub
This codec decodes the bitmap subtitles used in DVDs โ and the same subtitles can also be found in VobSub file pairs and in some Matroska files. Glow-up across containers, we love to see it.
Options
paletteโ specify the global palette used by the bitmaps. When stored in VobSub, the palette is normally specified in the index file; in Matroska, the palette is stored in the codec extra-data in the same format as in VobSub. In DVDs, the palette is stored in the IFO file, and therefore not available when reading from dumped VOB files. (RIP, she's just not there.)
The format for this option is a string containing 16 24-bits hexadecimal numbers (without 0x prefix) separated by commas, for example "0d00ee, ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1, 7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b".
ifo_paletteโ specify the IFO file from which the global palette is obtained. (experimental ๐)forced_subs_onlyโ only decode subtitle entries marked as forced. Some titles have forced and non-forced subtitles in the same track. Setting this flag to1will only keep the forced subtitles. Default value is0.
๐ง libzvbi-teletext
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext subtitles. It requires the presence of the libzvbi headers and library during configuration โ you need to explicitly configure the build with "--enable-libzvbi". No sneaky auto-enable here, bestie.
Options
txt_pageโ list of teletext page numbers to decode. Pages that do not match the specified list are dropped. You may use the special"*"string to match all pages, or"subtitle"to match all subtitle pages. Default value is*.txt_default_regionโ set the default character set used for decoding, a value between0and87(see ETS 300 706, Section 15, Table 32). Default value is-1, which does not override the libzvbi default. This option is needed for some legacy level 1.0 transmissions which cannot signal the proper charset. Legacy girlies need extra help sometimes, no shame. ๐ซถtxt_chop_topโ discards the top teletext line. Default value is1.txt_formatโ specifies the format of the decoded subtitles:bitmapโ the default format; you should use this for teletext pages, because certain graphics and colors cannot be expressed in simple text or even ASS.textโ simple text based output without formatting.assโ formatted ASS output, subtitle pages and teletext pages are returned in different styles; subtitle pages are stripped down to text, but an effort is made to keep the text alignment and the formatting.
txt_leftโ X offset of generated bitmaps, default is0.txt_topโ Y offset of generated bitmaps, default is0.txt_chop_spacesโ chops leading and trailing spaces and removes empty lines from the generated text. This option is useful for teletext based subtitles where empty spaces may be present at the start or at the end of the lines, or empty lines may be present between the subtitle lines because of double-sized teletext characters. Default value is1. Trim her, she deserves it. โจtxt_durationโ sets the display duration of the decoded teletext pages or subtitles in milliseconds. Default value is-1, which means infinity, or until the next subtitle event comes.txt_transparentโ force a transparent background of the generated teletext bitmaps. Default value is0, which means an opaque background.txt_opacityโ sets the opacity (0-255) of the teletext background. Iftxt_transparentis not set, it only affects characters between a start box and an end box, typically subtitles. Default value is0iftxt_transparentis set,255otherwise.
๐ ENCODERS ๐
Encoders are configured elements in FFmpeg which allow the encoding of multimedia streams. The other direction of the pipeline, basically โ she takes your frames and squishes them into a stream. ๐
When you configure your FFmpeg build, all the supported native encoders are enabled by default. Encoders requiring an external library must be enabled manually via the corresponding "--enable-lib" option. You can list all available encoders using the configure option "--list-encoders".
You can disable all the encoders with the configure option "--disable-encoders" and selectively enable / disable single encoders with the options "--enable-encoder=ENCODER" / "--disable-encoder=ENCODER".
The option -encoders of the ff* tools will display the list of enabled encoders. Go check her out, she'll tell you exactly who's available. ๐
๐ AUDIO ENCODERS ๐
Okay bestie, hereโs the tea on some of the audio encoders you can use right now. ๐งโจ
๐ aac ๐
Advanced Audio Coding (AAC) encoder. This is the default AAC encoder, natively built right into FFmpeg โ no extra plugin energy needed. ๐
๐๏ธ Options ๐๏ธ
bโ Set bit rate in bits/s. Setting this automatically activates constant bit rate (CBR) mode. If you donโt specify it, itโs set to128kbps.qโ Set quality for variable bit rate (VBR) mode. This option is valid only when using theffmpegcommand-line tool. For library interface users, useglobal_quality.cutoffโ Set cutoff frequency. If unspecified, the encoder is allowed to dynamically adjust the cutoff to improve clarity on low bitrates.aac_coderโ Set AAC encoder coding method. Possible values:twoloopโ Two loop searching (TLS) method. This is the default method.
This method first sets quantizers depending on band thresholds and then tries to find an optimal combination by adding or subtracting a specific value from all quantizers and adjusting some individual quantizer a little. It will tune itself based on whether aac_is, aac_ms and aac_pns are enabled.
anmrโ Average noise to mask ratio (ANMR) trellis-based solution.
This is an experimental coder which currently produces lower quality, is more unstable and is slower than the default twoloop coder but has potential. It currently has no support for the aac_is or aac_pns options. Not currently recommended.
fastโ Constant quantizer method.
Uses a cheaper version of the twoloop algorithm that doesnโt try to do as many clever adjustments. Worse with low bitrates (less than 64kbps), but is better and much faster at higher bitrates.
aac_msโ Sets mid/side coding mode. The default value ofautoautomatically uses M/S with bands that will benefit from such coding. You can force it for all bands withenable, which is mainly useful for debugging, or disable it withdisable.aac_isโ Sets intensity stereo coding tool usage. By default itโs enabled and will automatically toggle IS for similar pairs of stereo bands if thatโs beneficial. You can disable it for debugging by setting the value todisable.aac_pnsโ Uses perceptual noise substitution to replace low entropy high frequency bands with imperceptible white noise during the decoding process. By default itโs enabled, but you can disable it for debugging withdisable.aac_tnsโ Enables the use of a multitap FIR filter which spans through the high frequency bands to hide quantization noise during the encoding process and is reverted by the decoder. As well as decreasing unpleasant artifacts in the high range, this also reduces entropy in the high bands and allows more bits to be used by the mid-low bands. By default itโs enabled, but you can disable it for debugging by setting the option todisable.aac_ltpโ Enables the use of the long term prediction extension which increases coding efficiency in very low bandwidth situations, like encoding voice or solo piano music, by extending constant harmonic peaks in bands throughout frames. This option is implied byprofile:a aac_low. Use it in conjunction with-arto decrease the samplerate.profileโ Sets the encoding profile. Possible values:aac_lowโ The default, AAC "Low-complexity" profile. Itโs the most compatible and produces decent quality.mpeg2_aac_lowโ Equivalent to-profile:a aac_low -aac_pns 0. PNS was introduced with the MPEG4 specifications.aac_ltpโ Long term prediction profile, enabled by and will enable theaac_ltpoption. Introduced in MPEG4.
If this option is unspecified it is set to aac_low.
๐ฅ ac3 and ac3_fixed ๐ฅ
AC-3 audio encoders. These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366. ๐ฌ
The ac3 encoder uses floating-point math, while the ac3_fixed encoder only uses fixed-point integer math. This does not mean one is always faster โ just that one or the other may be better suited to a particular system. The ac3_fixed encoder is not the default codec for any of the output formats, so you have to specify it explicitly using the option -acodec ac3_fixed to use it.
๐ผ AC-3 Metadata ๐ผ
The AC-3 metadata options are used to set parameters that describe the audio, but in most cases they do not affect the audio encoding itself. Some of these options directly affect or influence the decoding and playback of the resulting bitstream, while others are just for informational purposes. A few of the options will add bits to the output stream that could otherwise be used for audio data, and will thus affect the quality of the output. Those will be indicated accordingly with a note in the option list below. ๐
These parameters are described in detail in several publicly-available documents:
http://www.atsc.org/cms/standards/a_52-2010.pdfhttp://www.atsc.org/cms/standards/a_54a_with_corr_1.pdfhttp://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/18_Metadata.Guide.pdfhttp://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/46_DDEncodingGuidelines.pdf
Metadata Control Options
-per_frame_metadataboolean โ Allow Per-Frame Metadata. Specifies if the encoder should check for changing metadata for each frame.0โ The metadata values set at initialization will be used for every frame in the stream. (default)1โ Metadata values can be changed before encoding each frame.
Downmix Levels
-center_mixlevlevel โ Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo. This field will only be written to the bitstream if a center channel is present. The value is specified as a scale factor. There are 3 valid values:0.707โ Apply-3dBgain0.595โ Apply-4.5dBgain (default)0.500โ Apply-6dBgain
-surround_mixlevlevel โ Surround Mix Level. The amount of gain the decoder should apply to the surround channel(s) when downmixing to stereo. This field will only be written to the bitstream if one or more surround channels are present. The value is specified as a scale factor. There are 3 valid values:0.707โ Apply-3dBgain0.500โ Apply-6dBgain (default)0.000โ Silence Surround Channel(s)
Audio Production Information
Audio Production Information is optional info describing the mixing environment. Either none or both of the fields are written to the bitstream. โจ
-mixing_levelnumber โ Mixing Level. Specifies peak sound pressure level (SPL) in the production environment when the mix was mastered. Valid values are80to111, or-1for unknown or not indicated. The default value is-1, but that value cannot be used if the Audio Production Information is written to the bitstream. So if theroom_typeoption is not the default value, themixing_leveloption must not be-1.-room_typetype โ Room Type. Describes the equalization used during the final mixing session at the studio or on the dubbing stage. A large room is a dubbing stage with the industry standard X-curve equalization; a small room has flat equalization. This field will not be written to the bitstream if both themixing_leveloption and theroom_typeoption have the default values.0,notindicatedโ Not Indicated (default)1,largeโ Large Room2,smallโ Small Room
Other Metadata Options
-copyrightboolean โ Copyright Indicator. Specifies whether a copyright exists for this audio.0,offโ No Copyright Exists (default)1,onโ Copyright Exists
-dialnormvalue โ Dialogue Normalization. Indicates how far the average dialogue level of the program is below digital 100% full scale (0 dBFS). This parameter determines a level shift during audio reproduction that sets the average volume of the dialogue to a preset level. The goal is to match volume level between program sources. A value of-31dBwill result in no volume level change, relative to the source volume, during audio reproduction. Valid values are whole numbers in the range-31to-1, with-31being the default.-dsur_modemode โ Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround (Pro Logic). This field will only be written to the bitstream if the audio stream is stereo. Using this option does NOT mean the encoder will actually apply Dolby Surround processing.0,notindicatedโ Not Indicated (default)1,offโ Not Dolby Surround Encoded2,onโ Dolby Surround Encoded
-originalboolean โ Original Bit Stream Indicator. Specifies whether this audio is from the original source and not a copy.0,offโ Not Original Source1,onโ Original Source (default)
Extended Bitstream Information
The extended bitstream options are part of the Alternate Bit Stream Syntax as specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts. If any one parameter in a group is specified, all values in that group will be written to the bitstream. Default values are used for those that are written but have not been specified. If the mixing levels are written, the decoder will use these values instead of the ones specified in the center_mixlev and surround_mixlev options if it supports the Alternate Bit Stream Syntax. ๐ง
Extended Bitstream Information - Part 1
-dmix_modemode โ Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt (Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.0,notindicatedโ Not Indicated (default)1,ltrtโ Lt/Rt Downmix Preferred2,loroโ Lo/Ro Downmix Preferred
-ltrt_cmixlevlevel โ Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo in Lt/Rt mode.1.414โ Apply+3dBgain1.189โ Apply+1.5dBgain1.000โ Apply0dBgain0.841โ Apply-1.5dBgain
Okay so the level list wraps up like this, bestie:
0.707โ Apply -3.0dB gain0.595โ Apply -4.5dB gain (default)0.500โ Apply -6.0dB gain0.000โ Silence Center Channel-ltrt_surmixlev levelโ Lt/Rt Surround Mix Level. This is how much gain the decoder should slap onto the surround channel(s) when it downmixes to stereo in Lt/Rt mode.0.841โ Apply -1.5dB gain0.707โ Apply -3.0dB gain0.595โ Apply -4.5dB gain0.500โ Apply -6.0dB gain (default)0.000โ Silence Surround Channel(s)
-loro_cmixlev levelโ Lo/Ro Center Mix Level. This is how much gain the decoder should apply to the center channel when downmixing to stereo in Lo/Ro mode.1.414โ Apply +3dB gain1.189โ Apply +1.5dB gain1.000โ Apply 0dB gain0.841โ Apply -1.5dB gain0.707โ Apply -3.0dB gain0.595โ Apply -4.5dB gain (default)0.500โ Apply -6.0dB gain0.000โ Silence Center Channel
-loro_surmixlev levelโ Lo/Ro Surround Mix Level. This is how much gain the decoder should apply to the surround channel(s) when downmixing to stereo in Lo/Ro mode.0.841โ Apply -1.5dB gain0.707โ Apply -3.0dB gain0.595โ Apply -4.5dB gain0.500โ Apply -6.0dB gain (default)0.000โ Silence Surround Channel(s)
๐ซถ Extended Bitstream Information - Part 2
-dsurex_mode modeโ Dolby Surround EX Mode. Tells you whether the stream uses Dolby Surround EX (7.1 matrixed to 5.1). Using this option does NOT mean the encoder will actually apply Dolby Surround EX processing.0/notindicatedโ Not Indicated (default)1/onโ Dolby Surround EX Off2/offโ Dolby Surround EX On
-dheadphone_mode modeโ Dolby Headphone Mode. Tells you whether the stream uses Dolby Headphone encoding (multi-channel matrixed to 2.0 for headphones). Using this option does NOT mean the encoder will actually apply Dolby Headphone processing.0/notindicatedโ Not Indicated (default)1/onโ Dolby Headphone Off2/offโ Dolby Headphone On
-ad_conv_type typeโ A/D Converter Type. Tells you whether the audio has passed through HDCD A/D conversion.0/standardโ Standard A/D Converter (default)1/hdcdโ HDCD A/D Converter
๐ Other AC-3 Encoding Options
-stereo_rematrixing booleanโ Stereo Rematrixing. Turns rematrixing on/off for stereo input. This is an optional AC-3 feature that bumps quality by selectively encoding the left/right channels as mid/side. Itโs enabled by default, and itโs highly recommended that you leave it enabled except for testing purposes.cutoff frequencyโ Sets the lowpass cutoff frequency. If you donโt specify it, the encoder picks a default determined by various other encoding parameters.
๐ Floating-Point-Only AC-3 Encoding Options
Heads up: these options are only valid for the floating-point encoder, and they do not exist for the fixed-point encoder because the corresponding features arenโt implemented in fixed-point. No cap.
-channel_coupling booleanโ Enables/Disables channel coupling, which is an optional AC-3 feature that increases quality by combining high frequency information from multiple channels into a single channel. The per-channel high frequency info gets sent with less accuracy in both the frequency and time domains. This lets more bits go to lower frequencies while preserving enough information to reconstruct the high frequencies. This option is enabled by default for the floating-point encoder and should generally stay enabled except for testing purposes or to increase encoding speed.-1/autoโ Selected by Encoder (default)0/offโ Disable Channel Coupling1/onโ Enable Channel Coupling
-cpl_start_band numberโ Coupling Start Band. Sets the channel coupling start band, from1to15. If you use a value higher than the bandwidth, it gets reduced to1less than the coupling end band. Ifautois used, the start band is determined by the encoder based on the bit rate, sample rate, and channel layout. This option has no effect if channel coupling is disabled.-1/autoโ Selected by Encoder (default)
๐ธ flac
FLAC (Free Lossless Audio Codec) Encoder
โจ Options
The following options are supported by FFmpegโs flac encoder. Slay.
compression_levelโ Sets the compression level. This chooses defaults for many other options if they arenโt set explicitly. Valid values are from0to12, and5is the default.frame_sizeโ Sets the size of the frames in samples per channel.lpc_coeff_precisionโ Sets the LPC coefficient precision. Valid values are from1to15, and15is the default.lpc_typeโ Sets the first stage LPC algorithm.noneโ LPC is not usedfixedโ fixed LPC coefficientslevinsoncholesky
lpc_passesโ Number of passes to use for Cholesky factorization during LPC analysis.min_partition_orderโ The minimum partition order.max_partition_orderโ The maximum partition order.prediction_order_methodestimation2level4level8levelsearchโ Bruteforce searchlog
ch_modeโ Channel mode.autoโ The mode is chosen automatically for each frameindepโ Channels are independently codedleft_sideright_sidemid_side
exact_rice_parametersโ Chooses if rice parameters are calculated exactly or approximately. If set to1, theyโre chosen exactly โ which slows the code down slightly and improves compression slightly. Cute little tradeoff.multi_dim_quantโ Multi Dimensional Quantization. If set to1, a 2nd stage LPC algorithm is applied after the first stage to finetune the coefficients. This is quite slow and slightly improves compression.
๐ฆ opus
Opus encoder.
This is a native FFmpeg encoder for the Opus format. Currently, itโs in development and only implements the CELT part of the codec. Its quality is usually worse and at best is equal to the libopus encoder.
โจ Options
bโ Set bit rate in bits/s. If unspecified, it uses the number of channels and the layout to make a good guess.opus_delayโ Sets the maximum delay in milliseconds. Lower delays than20mswill very quickly decrease quality.
๐ libfdk_aac
libfdk-aac AAC (Advanced Audio Coding) encoder wrapper.
The libfdk-aac library is based on the Fraunhofer FDK AAC code from the Android project.
It requires the presence of the libfdk-aac headers and library during configuration. You need to explicitly configure the build with --enable-libfdk-aac. The library is also incompatible with GPL, so if you allow the use of GPL, you should configure with --enable-gpl --enable-nonfree --enable-libfdk-aac.
This encoder has support for the AAC-HE profiles.
VBR encoding, enabled through the vbr or flags +qscale options, is experimental and only works with some combinations of parameters.
Support for encoding 7.1 audio is only available with libfdk-aac 0.1.3 or higher.
For more information see the fdk-aac project at <http://sourceforge.net/p/opencore-amr/fdk-aac/>.
โจ Options
The following options are mapped on the shared FFmpeg codec options.
bโ Set bit rate in bits/s. If the bitrate is not explicitly specified, it is automatically set to a suitable value depending on the selected profile. In case VBR mode is enabled the option is ignored.arโ Set audio sampling rate (in Hz).channelsโ Set the number of audio channels.flags +qscaleโ Enable fixed quality, VBR (Variable Bit Rate) mode. Note that VBR is implicitly enabled when thevbrvalue is positive.cutoffโ Set cutoff frequency. If not specified (or explicitly set to0) it will use a value automatically computed by the library. Default value is0.profileโ Set audio profile.
The following profiles are recognized:
aac_lowโ Low Complexity AAC (LC)aac_heโ High Efficiency AAC (HE-AAC)aac_he_v2โ High Efficiency AAC version 2 (HE-AACv2)aac_ldโ Low Delay AAC (LD)aac_eldโ Enhanced Low Delay AAC (ELD)
If not specified it is set to aac_low.
The following are private options of the libfdk_aac encoder. Secret menu energy, honestly.
afterburnerโ Enable afterburner feature if set to1, disabled if set to0. This improves the quality but also the required processing power.
Default value is 1.
eld_sbrโ Enable SBR (Spectral Band Replication) for ELD if set to1, disabled if set to0.
Default value is 0.
eld_v2โ Enable ELDv2 (LD-MPS extension for ELD stereo signals) for ELDv2 if set to1, disabled if set to0.
Note that option is available when fdk-aac version (AACENCODER_LIB_VL0.AACENCODER_LIB_VL1.AACENCODER_LIB_VL2) > (4.0.0).
Default value is 0.
signalingโ Set SBR/PS signaling style.
It can assume one of the following values:
defaultโ choose signaling implicitly (explicit hierarchical by default, implicit if global header is disabled)implicitโ implicit backwards compatible signalingexplicit_sbrโ explicit SBR, implicit PS signalingexplicit_hierarchicalโ explicit hierarchical signaling
Default value is default.
latmโ Output LATM/LOAS encapsulated data if set to1, disabled if set to0.
Default value is 0.
header_periodโ Set StreamMuxConfig and PCE repetition period (in frames) for sending in-band configuration buffers within LATM/LOAS transport layer.
Must be a 16-bits non-negative integer.
Default value is 0.
vbrโ Set VBR mode, from1to5.1is lowest quality (though still pretty good) and5is highest quality. A value of0will disable VBR, and CBR (Constant Bit Rate) is enabled.
Currently only the aac_low profile supports VBR encoding.
VBR modes 1โ5 are basically a vibe check for bitrate โ they line up roughly like this:
32 kbps/channel40 kbps/channel48-56 kbps/channel64 kbps/channel- about
80-96 kbps/channel
Default value is 0 โ aka "no thoughts, just defaults" โจ
frame_lengthโ sets the audio frame length in samples, bestie. The default is whatever the library's internal default is (iykyk), so go read the library's docs for which values are actually supported ๐ซถ
Examples ๐
- Wanna convert an audio file to VBR AAC in an M4A (MP4) container using
ffmpeg? Slay, here's the line:
ffmpeg -i input.wav -codec:a libfdk_aac -vbr 3 output.m4a
- Or convert to CBR 64k kbps AAC using the High-Efficiency AAC profile โ iconic:
ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a
๐ธ liblc3 ๐ธ
The liblc3 LC3 (Low Complexity Communication Codec) encoder wrapper. Literally the moment ๐
You need the liblc3 headers and library present during configuration, and you have to explicitly configure the build with --enable-liblc3.
This encoder supports the Bluetooth SIG LC3 codec for the LE Audio protocol, plus these LC3plus features:
- Frame duration of
2.5and5ms. - High-Resolution mode,
48 KHz, and96 kHzsampling rates.
For more info, the liblc3 project lives at <https://github.com/google/liblc3> โ go be nosy โจ
Options ๐ฆ
These options are mapped onto the shared FFmpeg codec options.
bbitrate โ set the bit rate in bits/s. This decides the fixed size of the encoded frames for whichever frame duration you picked.arfrequency โ set the audio sampling rate (in Hz).channelsโ set the number of audio channels.frame_durationโ set the audio frame duration in milliseconds. Default is10ms. Allowed frame durations are2.5ms,5ms,7.5msand10ms. LC3 (Bluetooth LE Audio) allows7.5msand10ms; LC3plus allows2.5ms,5msand10ms.
The 10ms frame duration is available in both LC3 and LC3 plus standard, no cap. In this mode the produced bitstream can be referenced either as LC3 or LC3plus ๐
high_resolutionboolean โ enable the high-resolution mode by setting it to1. High-resolution mode is available with all LC3plus frame durations and for sampling rates of48 KHzand96 KHz.
The encoder automatically turns this mode off at lower sampling rates and activates it at 96 KHz.
This mode should be preferred at high bitrates โ in it, the audio bandwidth always goes up to the Nyquist frequency, compared to LC3 at 48 KHz which limits the bandwidth to 20 KHz. The range! ๐
๐ libmp3lame ๐
The LAME (Lame Ain't an MP3 Encoder) MP3 encoder wrapper. A classic, honestly.
You need the libmp3lame headers and library present during configuration, and you must explicitly configure the build with --enable-libmp3lame.
Check out libshine if you want a fixed-point MP3 encoder โ although it's lower quality, just so you know ๐
Options โจ
These are supported by the libmp3lame wrapper. The lame-equivalent names are in parentheses.
b(-b) โ set the bitrate expressed in bits/s for CBR or ABR. LAME's "bitrate" is expressed in kilobits/s.q(-V) โ set the constant quality setting for VBR. This option is only valid when you're using theffmpegcommand-line tool. Library interface users, useglobal_qualityinstead ๐ซถcompression_level(-q) โ set the algorithm quality. Valid arguments are integers in the0-9range, where0means highest quality but slowest, and9means fastest while producing the worst quality. Pick your fighter ๐cutoff(--lowpass) โ set the lowpass cutoff frequency. If you don't specify it, the encoder dynamically adjusts the cutoff.reservoirโ enable use of the bit reservoir when set to1. Default is1. LAME has this on by default but it can be overridden by using the--noresoption.joint_stereo(-m j) โ lets the encoder use, frame by frame, either L/R stereo or mid/side stereo. Default is1.abr(--abr) โ enable ABR when set to1. The lame--abrsets the target bitrate, while this option only tells FFmpeg to use ABR โ it still relies onbto set the bitrate. Teamwork, I guess ๐คcopyright(-c) โ set the MPEG audio copyright flag when set to1. Default is0(disabled).original(-o) โ set the MPEG audio original flag when set to1. Default is1(enabled).
๐ฆ libopencore-amrnb ๐ฆ
The OpenCORE Adaptive Multi-Rate Narrowband encoder.
You need the libopencore-amrnb headers and library present during configuration, and you must explicitly configure the build with --enable-libopencore-amrnb --enable-version3.
This one is a mono-only encoder, periodt. Officially it only supports the 8000Hz sample rate, but you can override that by setting strict to unofficial or lower.
Options ๐
bโ set the bitrate in bits per second. Only these bitrates are supported โ otherwise libavcodec will round to the nearest valid bitrate:
4750
5150
5900
6700
7400
7950
10200
12200
dtxโ allow discontinuous transmission (generate comfort noise) when set to1. Default is0(disabled).
๐ libopus ๐
The libopus Opus Interactive Audio Codec encoder wrapper. Main character energy, fr fr.
You need the libopus headers and library present during configuration, and you must explicitly configure the build with --enable-libopus.
Option Mapping ๐
Most libopus options are modelled after the opusenc utility from opus-tools. Here's the mapping chart describing options supported by the libopus wrapper, with their opusenc-equivalent in parentheses.
b(bitrate) โ set the bit rate in bits/s. FFmpeg'sboption is expressed in bits/s, while opusenc'sbitrateis in kilobits/s. Watch those units bestie ๐ญvbr(vbr,hard-cbr, andcvbr) โ set the VBR mode. The FFmpegvbroption has these valid arguments, with the opusenc equivalents in parentheses:off(hard-cbr) โ use constant bit rate encoding.on(vbr) โ use variable bit rate encoding (the default).constrained(cvbr) โ use constrained variable bit rate encoding.
compression_level(comp) โ set the encoding algorithm complexity. Valid options are integers in the0-10range.0gives the fastest encodes but lower quality, while10gives the highest quality but slowest encoding. The default is10.frame_duration(framesize) โ set the maximum frame size, or duration of a frame, in milliseconds. The argument must be exactly one of:2.5,5,10,20,40,60. Smaller frame sizes get you lower latency but less quality at a given bitrate. Sizes greater than20msare only interesting at fairly low bitrates. The default is20ms.packet_loss(expect-loss) โ set the expected packet loss percentage. The default is0.fec(n/a) โ enable inband forward error correction.packet_lossmust be non-zero to take advantage of it โ the frequency of FEC 'side-data' is proportional to the expected packet loss. Default is disabled.application(N.A.) โ set the intended application type. Valid options:voipโ favor improved speech intelligibility.audioโ favor faithfulness to the input (the default).lowdelayโ restrict to only the lowest delay modes by disabling voice-optimized modes.
cutoff(N.A.) โ set the cutoff bandwidth in Hz. The argument must be exactly one of:4000,6000,8000,12000, or20000, corresponding to narrowband, mediumband, wideband, super wideband, and fullband respectively. The default is0(cutoff disabled). Note that libopus forces a wideband cutoff for bitrates <15 kbps, unless CELT-only (application set tolowdelay) mode is used. Sneaky but valid ๐mapping_family(mapping_family) โ set the channel mapping family the encoder should use. The default value of-1uses mapping family0for mono and stereo inputs, and mapping family1otherwise. The default also disables the surround masking and LFE bandwidth optimizations in libopus, and requires that the input contains 8 channels or fewer.
Other values include 0 for mono and stereo, 1 for surround sound with masking and LFE bandwidth optimizations, and 255 for independent streams with an unspecified channel layout.
apply_phase_inv(N.A.) (requires libopus >= 1.2) โ if set to0, disables the use of phase inversion for intensity stereo, improving the quality of mono downmixes but slightly reducing normal stereo quality. The default is1(phase inversion enabled).
๐ libshine ๐
The Shine Fixed-Point MP3 encoder wrapper.
Shine is a fixed-point MP3 encoder. It performs far better on platforms without an FPU โ think armel CPUs, and some phones and tablets. But because it's more targeted at performance than quality, it's not on par with LAME and other production-grade encoders quality-wise. Also, according to the project's homepage, this encoder may not be free of bugs, since the code was written a long time ago and the project was dead for at least 5 years. Not me trusting it anyway ๐
This encoder only supports stereo and mono input, and it's also CBR-only.
The original project (last updated in early 2007) is at <http://sourceforge.net/projects/libshine-fxp/>. We only support the updated fork by the Savonet/Liquidsoap project at <https://github.com/savonet/shine>.
You need the libshine headers and library present during configuration, and you must explicitly configure the build with --enable-libshine.
See also libmp3lame ๐
Options ๐ง
These are supported by the libshine wrapper. The shineenc-equivalent names are in parentheses.
b(-b) โ set the bitrate expressed in bits/s for CBR. Theshineenc -boption is expressed in kilobits/s.
๐ libtwolame ๐
The TwoLAME MP2 encoder wrapper.
You need the libtwolame headers and library present during configuration, and you must explicitly configure the build with --enable-libtwolame.
Options โญ
These are supported by the libtwolame wrapper. The twolame-equivalent options follow the FFmpeg ones and are in parentheses.
b(-b) โ set the bitrate expressed in bits/s for CBR. The twolameboption is expressed in kilobits/s. Default value is128k.q(-V) โ set the quality for experimental VBR support. The maximum value range is from-50to50, and the useful range is from-10to10. The higher the value, the better the quality. This option is only valid when using theffmpegcommand-line tool. Library interface users, useglobal_qualityinstead ๐ซถ
okay so picking up right where we left off โ the next encoder knobs are giving very much โtiny details, big vibe checksโ ๐
mode(--mode) โ sets the mode of the resulting audio. Possible values are:autoโ choose mode automatically based on the input. This is the default.stereoโ stereo.joint_stereoโ joint stereo.dual_channelโ dual channel.monoโ mono.
psymodel(--psyc-mode) โ sets the psychoacoustic model to use in encoding. The argument must be an integer between-1and4, inclusive. The higher the value, the better the quality. The default value is3.energy_levels(--energy) โ enables energy levels extensions when set to1. The default value is0(disabled).error_protection(--protect) โ enables CRC error protection when set to1. The default value is0(disabled).copyright(--copyright) โ sets the MPEG audio copyright flag when set to1. The default value is0(disabled).original(--original) โ sets the MPEG audio original flag when set to1. The default value is0(disabled).
๐ง libvo-amrwbenc ๐ง
VisualOn Adaptive Multi-Rate Wideband encoder โ say that five times fast ๐ญ
Requires the presence of the libvo-amrwbenc headers and library during configuration. You need to explicitly configure the build with --enable-libvo-amrwbenc --enable-version3.
This is a mono-only encoder. Officially it only supports 16000Hz sample rate, but you can override it by setting strict to unofficial or lower.
โจ Options โจ
bโ set bitrate in bits/s. Only the following bitrates are supported, otherwise libavcodec will round to the nearest valid bitrate:6600885012650142501585018250198502305023850
dtxโ allow discontinuous transmission (generate comfort noise) when set to1. The default value is0(disabled).
๐ฆ libvorbis ๐ฆ
libvorbis encoder wrapper โ literally the classic Vorbis vibe โจ
Requires the presence of the libvorbisenc headers and library during configuration. You need to explicitly configure the build with --enable-libvorbis.
โจ Options โจ
The following options are supported by the libvorbis wrapper. The oggenc-equivalent of the options are listed in parentheses.
To get a more accurate and extensive documentation of the libvorbis options, consult the libvorbisenc's and oggenc's documentations. See http://xiph.org/vorbis/, http://wiki.xiph.org/Vorbis-tools, and oggenc(1).
b(-b) โ set bitrate expressed in bits/s for ABR.oggenc -bis expressed in kilobits/s.q(-q) โ set constant quality setting for VBR. The value should be a float number in the range of-1.0to10.0. The higher the value, the better the quality. The default value is3.0.
This option is valid only using the ffmpeg command-line tool. For library interface users, use global_quality.
cutoff(--advanced-encode-option lowpass_frequency=N) โ set cutoff bandwidth in Hz, a value of0disables cutoff. oggenc's related option is expressed in kHz. The default value is0(cutoff disabled).minrate(-m) โ set minimum bitrate expressed in bits/s.oggenc -mis expressed in kilobits/s.maxrate(-M) โ set maximum bitrate expressed in bits/s.oggenc -Mis expressed in kilobits/s. This only has effect on ABR mode.iblock(--advanced-encode-option impulse_noisetune=N) โ set noise floor bias for impulse blocks. The value is a float number from-15.0to0.0. A negative bias instructs the encoder to pay special attention to the crispness of transients in the encoded audio. The tradeoff for better transient response is a higher bitrate.
๐ mjpeg ๐
Motion JPEG encoder.
โจ Options โจ
huffmanโ set the huffman encoding strategy. Possible values:defaultโ use the default huffman tables. This is the default strategy.optimalโ compute and use optimal huffman tables.
๐ wavpack ๐
WavPack lossless audio encoder.
โจ Options โจ
The equivalent options for wavpack command line utility are listed in parentheses.
Shared options
The following shared options are effective for this encoder. Only special notes about this particular encoder will be documented here. For the general meaning of the options, see the Codec Options chapter.
frame_size(--blocksize) โ for this encoder, the range for this option is between128and131072. Default is automatically decided based on sample rate and number of channel.
For the complete formula of calculating default, see libavcodec/wavpackenc.c.
compression_level(-f,-h,-hh, and-x) โ yes, that's literally the whole line in the manual. No extra lore here ๐ซถ
Private options
joint_stereo(-j) โ set whether to enable joint stereo. Valid values are:on(1) โ force mid/side audio encoding.off(0) โ force left/right audio encoding.autoโ let the encoder decide automatically.
optimize_monoโ set whether to enable optimization for mono. This option is only effective for non-mono streams. Available values:onโ enabledoffโ disabled
๐ฌ VIDEO ENCODERS ๐ฌ
A description of some of the currently available video encoders follows.
๐น๏ธ a64_multi, a64_multi5 ๐น๏ธ
A64 / Commodore 64 multicolor charset encoder. a64_multi5 is extended with 5th color (colram).
๐๏ธ Cinepak ๐๏ธ
Cinepak aka CVID encoder. Compatible with Windows 3.1 and vintage MacOS.
โจ Options โจ
ginteger โ keyframe interval. A keyframe is inserted at least every-gframes, sometimes sooner.q:vinteger โ quality factor. Lower is better. Higher gives lower bitrate. The following table lists bitrates when encodingakiyo_cif.y4mfor various values of-q:vwith-g 100:-q:v 11918 kb/s-q:v 21735 kb/s-q:v 41500 kb/s-q:v 101041 kb/s-q:v 20826 kb/s-q:v 40553 kb/s-q:v 100394 kb/s-q:v 200312 kb/s-q:v 400266 kb/s-q:v 1000237 kb/s
max_extra_cb_iterationsinteger โ max extra codebook recalculation passes, more is better and slower.skip_empty_cbboolean โ avoid wasting bytes, ignore vintage MacOS decoder.max_stripsinteger โ the maximum number of strips to use. Combined note for both strip options: wider range sometimes improves quality. More strips is generally better quality but costs more bits. Fewer strips tend to yield more keyframes. Vintage compatible is1..3.min_stripsinteger โ the minimum number of strips to use. Same combined note as above: wider range sometimes improves quality. More strips is generally better quality but costs more bits. Fewer strips tend to yield more keyframes. Vintage compatible is1..3.strip_number_adaptivityinteger โ how much number of strips is allowed to change between frames. Higher is better but slower.
๐ง ffv1 ๐ง
FFv1 Encoder.
โจ Options โจ
The following options are supported by FFmpeg's FFv1 encoder.
contextโ sets the context size,0(default) is small,1is big.coderโ set the coder:riceโ Golomb rice coderrange_defโ range coder with default tablerange_tabโ range coder with custom table
slicecrcโ-1(default, automatic),1use crc with zero initial and final state,2use crc with non zero initial and final state.qtableโ possible values:defaultโ default, automatic8bitโ use 8bit defaultgreater8bitโ use >8bit default
remap_optimizerโ0-5, default3, how much effort the encoder puts into optimizing the remap table.
๐ GIF ๐
GIF image/animation encoder.
โจ Options โจ
gifflagsinteger โ sets the flags used for GIF encoding.offsettingโ enables picture offsetting. Default is enabled.transdiffโ enables transparency detection between frames. Default is enabled.
gifimageinteger โ enables encoding one full GIF image per frame, rather than an animated GIF. Default value is0.global_paletteinteger โ writes a palette to the global GIF header where feasible.
If disabled, every frame will always have a palette written, even if there is a global palette supplied.
Default value is 1.
๐ฆ Hap ๐ฆ
Vidvox Hap video encoder.
โจ Options โจ
formatinteger โ specifies the Hap format to encode.haphap_alphahap_q
Default value is hap.
chunksinteger โ specifies the number of chunks to split frames into, between1and64. This permits multithreaded decoding of large frames, potentially at the cost of data-rate. The encoder may modify this value to divide frames evenly.
Default value is 1.
compressorinteger โ specifies the second-stage compressor to use. If set tonone, chunks will be limited to1, as chunked uncompressed frames offer no benefit.nonesnappy
Default value is snappy.
๐ผ๏ธ jpeg2000 ๐ผ๏ธ
The native jpeg 2000 encoder is lossy by default, the -q:v option can be used to set the encoding quality. Lossless encoding can be selected with -pred 1.
โจ Options โจ
formatinteger โ can be set to eitherj2korjp2(the default) that makes it possible to store non-rgb pix_fmts.tile_widthinteger โ sets tile width. Range is1to1073741824. Default is256.tile_heightinteger โ sets tile height. Range is1to1073741824. Default is256.predinteger โ allows setting the discrete wavelet transform (DWT) type:dwt97int(Lossy)dwt53(Lossless)
Default is dwt97int.
sopboolean โ enable this to add SOP marker at the start of each packet. Disabled by default.ephboolean โ enable this to add EPH marker at the end of each packet header. Disabled by default.proginteger โ sets the progression order to be used by the encoder. Possible values are:lrcprlcprpclpcrlcprl
Set to lrcp by default.
layer_ratesstring โ by default, when this option is not used, compression is done using the quality metric. This option allows for compression using compression ratio. The compression ratio for each level could be specified. The compression ratio of a layerlspecies the what ratio of total file size is contained in the firstllayers.
Example usage:
ffmpeg -i input.bmp -c:v jpeg2000 -layer_rates "100,10,1" output.j2k
This would compress the image to contain 3 layers, where the data contained in the first layer would be compressed by 1000 times, compressed by 100 in the first two layers, and shall contain all data while using all 3 layers.
๐ฆ librav1e ๐ฆ
rav1e AV1 encoder wrapper.
okay so bestie, the rav1e wrapper needs the rav1e headers and library present when you configure โ you gotta explicitly configure the build with --enable-librav1e. no drive-by installs, she needs a formal invite ๐
Options
qmaxโ sets the max quantizer to use when you're in bitrate mode.qminโ sets the min quantizer to use when you're in bitrate mode.qpโ uses quantizer mode to encode at the given quantizer (0-255).speedโ picks the speed preset (0-10) to encode with.tilesโ picks how many tiles to encode with.tile-rowsโ picks how many rows of tiles to encode with.tile-columnsโ picks how many columns of tiles to encode with.rav1e-paramsโ sets rav1e options using a list ofkey=valuepairs separated by":". Want the full menu? peeprav1e --helpfor the option list, iykyk.
Like, say you wanna pass librav1e encoding options with -rav1e-params, it's giving:
ffmpeg -i input -c:v librav1e -b:v 500K -rav1e-params speed=5:low_latency=true output.mp4
๐ฆ libaom-av1 ๐ฆ
the libaom AV1 encoder wrapper, she's the moment.
needs the libaom headers and library hanging around during configuration โ you have to explicitly configure the build with --enable-libaom.
Options
this wrapper supports the following standard libavcodec options, periodt:
bโ set the bitrate target in bits/second. by default this uses variable-bitrate mode. ifmaxrateandminrateare also set to the same value, then it uses constant-bitrate mode instead โ otherwise, ifcrfis set too, it uses constrained-quality mode. three modes, one flag, main character energy fr.g,keyint_minโ set key frame placement. the GOP size sets the maximum distance between key frames; if it's zero the output stream will be intra-only. the minimum distance is ignored unless it's the same as the GOP size, in which case key frames always show up at a fixed interval. not set by default, so without this option the library has completely free choice about where to place key frames โ she's improvising ๐qmin,qmaxโ set min/max quantisation values. valid range is 0 to 63 (warning: this does not match the quantiser values actually used by AV1 โ divide by four to map real quantiser values to this range, no cap). defaults to min/max, i.e. no constraint.minrate,maxrate,bufsize,rc_init_occupancyโ set rate control buffering parameters. not used if not set โ defaults to unconstrained variable bitrate.threadsโ set the number of threads to use while encoding. heads up: this may require thetilesorrow-mtoptions to also be set for the specified thread count to actually get used fully. defaults to the number of hardware threads supported by the host machine. ๐งprofileโ set the encoding profile. defaults to using the profile that matches the bit depth and chroma subsampling of the input.
the wrapper also has some specific options of her own:
cpu-usedโ set the quality/encoding speed tradeoff. valid range is 0 to 8, higher numbers meaning greater speed and lower quality. the default value is1, which will be slow and high quality. she's thorough, okay ๐ญauto-alt-refโ enable use of alternate reference frames. defaults to the internal default of the library.arnr-max-frames(frames) โ set altref noise reduction max frame count. default is-1.arnr-strength(strength) โ set altref noise reduction filter strength. range is-1to6. default is-1.aq-mode(aq-mode) โ set adaptive quantization mode. possible values:none(0) โ disabled.variance(1) โ variance-based.complexity(2) โ complexity-based.cyclic(3) โ cyclic refresh.
tune(tune) โ set the distortion metric the encoder is tuned with. default is"psnr".psnr(0)ssim(1)
lag-in-framesโ set the maximum number of frames the encoder may keep in flight at any one time for lookahead purposes. defaults to the internal default of the library.error-resilienceโ enable error resilience features:defaultโ improve resilience against losses of whole frames.
not enabled by default.
crfโ set the quality/size tradeoff for constant-quality (no bitrate target) and constrained-quality (with maximum bitrate target) modes. valid range is 0 to 63, higher numbers meaning lower quality and smaller output size. only used if set; by default only the bitrate target is used.static-threshโ set a change threshold on blocks below which they'll be skipped by the encoder. defined in arbitrary units as a nonnegative integer, defaulting to zero (no blocks are skipped).drop-thresholdโ set a threshold for dropping frames when close to rate control bounds. defined as a percentage of the target buffer โ when the rate control buffer falls below this percentage, frames get dropped until it's refilled above the threshold. defaults to zero (no frames are dropped). ๐ซถdenoise-noise-level(level) โ amount of noise to be removed for grain synthesis. grain synthesis is disabled if this option isn't set or is set to0.denoise-block-size(pixels) โ block size used for denoising for grain synthesis. if not set, the AV1 codec uses the default value of32.undershoot-pct(pct) โ set datarate undershoot (min) percentage of the target bitrate. range is-1to100. default is-1.overshoot-pct(pct) โ set datarate overshoot (max) percentage of the target bitrate. range is-1to1000. default is-1.minsection-pct(pct) โ minimum percentage variation of the GOP bitrate from the target bitrate. ifminsection-pctisn't set, the libaomenc wrapper computes it like so:"(minrate * 100 / bitrate)". range is-1to100. default is-1(unset).maxsection-pct(pct) โ maximum percentage variation of the GOP bitrate from the target bitrate. ifmaxsection-pctisn't set, the libaomenc wrapper computes it like so:"(maxrate * 100 / bitrate)". range is-1to5000. default is-1(unset).frame-parallel(boolean) โ enable frame parallel decodability features. default istrue.tilesโ set the number of tiles to encode the input video with, as columns x rows. larger numbers allow greater parallelism in both encoding and decoding, but may decrease coding efficiency. defaults to the minimum number of tiles required by the size of the input video (which is1x1โ that is, a single tile โ for sizes up to and including 4K). ๐tile-columns,tile-rowsโ set the number of tiles as log2 of the number of tile rows and columns. provided for compatibility with libvpx/VP9.row-mt(Requires libaom >= 1.0.0-759-g90a15f4f2) โ enable row based multi-threading. disabled by default.enable-cdef(boolean) โ enable Constrained Directional Enhancement Filter. the libaom-av1 encoder enables CDEF by default.enable-restoration(boolean) โ enable Loop Restoration Filter. default istruefor libaom-av1.enable-global-motion(boolean) โ enable the use of global motion for block prediction. default istrue.enable-intrabc(boolean) โ enable block copy mode for intra block prediction. this mode is useful for screen content. default istrue.enable-rect-partitions(boolean) (Requires libaom >= v2.0.0) โ enable rectangular partitions. default istrue.enable-1to4-partitions(boolean) (Requires libaom >= v2.0.0) โ enable 1:4/4:1 partitions. default istrue.enable-ab-partitions(boolean) (Requires libaom >= v2.0.0) โ enable AB shape partitions. default istrue.enable-angle-delta(boolean) (Requires libaom >= v2.0.0) โ enable angle delta intra prediction. default istrue.enable-cfl-intra(boolean) (Requires libaom >= v2.0.0) โ enable chroma predicted from luma intra prediction. default istrue.enable-filter-intra(boolean) (Requires libaom >= v2.0.0) โ enable filter intra predictor. default istrue.enable-intra-edge-filter(boolean) (Requires libaom >= v2.0.0) โ enable intra edge filter. default istrue.enable-smooth-intra(boolean) (Requires libaom >= v2.0.0) โ enable smooth intra prediction mode. default istrue.enable-paeth-intra(boolean) (Requires libaom >= v2.0.0) โ enable paeth predictor in intra prediction. default istrue.enable-palette(boolean) (Requires libaom >= v2.0.0) โ enable palette prediction mode. default istrue.enable-flip-idtx(boolean) (Requires libaom >= v2.0.0) โ enable extended transform type, includingFLIPADST_DCT,DCT_FLIPADST,FLIPADST_FLIPADST,ADST_FLIPADST,FLIPADST_ADST,IDTX,V_DCT,H_DCT,V_ADST,H_ADST,V_FLIPADST,H_FLIPADST. default istrue. that's a lotta types bestie, she ate ๐enable-tx64(boolean) (Requires libaom >= v2.0.0) โ enable 64-pt transform. default istrue.reduced-tx-type-set(boolean) (Requires libaom >= v2.0.0) โ use reduced set of transform types. default isfalse.use-intra-dct-only(boolean) (Requires libaom >= v2.0.0) โ use DCT only for INTRA modes. default isfalse.use-inter-dct-only(boolean) (Requires libaom >= v2.0.0) โ use DCT only for INTER modes. default isfalse.use-intra-default-tx-only(boolean) (Requires libaom >= v2.0.0) โ use Default-transform only for INTRA modes. default isfalse.enable-ref-frame-mvs(boolean) (Requires libaom >= v2.0.0) โ enable temporal mv prediction. default istrue.enable-reduced-reference-set(boolean) (Requires libaom >= v2.0.0) โ use reduced set of single and compound references. default isfalse.enable-obmc(boolean) (Requires libaom >= v2.0.0) โ enable obmc. default istrue.enable-dual-filter(boolean) (Requires libaom >= v2.0.0) โ enable dual filter. default istrue.enable-diff-wtd-comp(boolean) (Requires libaom >= v2.0.0) โ enable difference-weighted compound. default istrue.enable-dist-wtd-comp(boolean) (Requires libaom >= v2.0.0) โ enable distance-weighted compound. default istrue.enable-onesided-comp(boolean) (Requires libaom >= v2.0.0) โ enable one sided compound. default istrue.enable-interinter-wedge(boolean) (Requires libaom >= v2.0.0) โ enable interinter wedge compound. default istrue.enable-interintra-wedge(boolean) (Requires libaom >= v2.0.0) โ enable interintra wedge compound. default istrue.enable-masked-comp(boolean) (Requires libaom >= v2.0.0) โ enable masked compound. default istrue.enable-interintra-comp(boolean) (Requires libaom >= v2.0.0) โ enable interintra compound. default istrue.enable-smooth-interintra(boolean) (Requires libaom >= v2.0.0) โ enable smooth interintra mode. default istrue. โจ
aom-params
okay so this is where you pass libaom its little extras โ you give it a list of key=value pairs separated by :. Wanna know which keys exist? Go run aomenc --help and look at the section literally called "AV1 Specific Options" ๐
Like, for example, to specify libaom encoding options with -aom-params:
ffmpeg -i input -c:v libaom-av1 -b:v 500K -aom-params tune=psnr:enable-tpl-model=1 output.mp4
๐ liboapv ๐
The Advanced Professional Video codec encoder wrapper, bestie โจ
Fair warning: this encoder needs the liboapv headers and library chillin' there at configuration time, so you gotta explicitly configure your build with --enable-liboapv.
Many liboapv encoder options are mapped to FFmpeg global codec options, while the unique encoder options get handed to you through private options. iykyk ๐ซถ
The apv project website lives at https://github.com/AcademySoftwareFoundation/openapv.
โจ Options โจ
These are the ones the liboapv wrapper supports:
Want the extensive documentation of the liboapv options? Go consult the liboapv docs, queen ๐
presetโ set the quality-speed tradeoff, one offastest,fast,medium,slow,placebo,default.qpโ set the quantization parameter value for CQP rate control mode.oapv-params(parse_apv_params) โ set liboapvenc options using a list ofkey=valuepairs separated by:. Peep the liboapv encoder user guide for the list of accepted parameters.
๐ฆ libsvtav1 ๐ฆ
SVT-AV1 encoder wrapper, no cap ๐
Needs the SVT-AV1 headers and library present during configuration. You gotta explicitly configure the build with --enable-libsvtav1.
๐ธ Options ๐ธ
profileโ set the encoding profile.mainhighprofessional
levelโ set the operating point level. For example:'4.0'hielevelโ set the Hierarchical prediction levels.3level4levelโ this one is the default, fyi.
tierโ set the operating point tier.mainโ this is the default โจhigh
qmaxโ set the maximum quantizer to use when using a bitrate mode.qminโ set the minimum quantizer to use when using a bitrate mode.crfโ constant rate factor value used in crf rate control mode (0-63).qpโ set the quantizer used in cqp rate control mode (0-63).sc_detectionโ enable scene change detection.la_depthโ set number of frames to look ahead (0-120).presetโ set the quality-speed tradeoff, in the range0to13. Higher values are faster but lower quality (you get what you pay for, literally ๐).tile_rowsโ set log2 of the number of rows of tiles to use (0-6).tile_columnsโ set log2 of the number of columns of tiles to use (0-4).svtav1-paramsโ set SVT-AV1 options using a list ofkey=valuepairs separated by:. See the SVT-AV1 encoder user guide for a list of accepted parameters.
๐ libsvtjpegxs ๐
SVT-JPEG-XS encoder wrapper, she's niche and she's iconic ๐
Needs the SVT-JPEG-XS headers and library during configuration. You gotta explicitly configure the build with --enable-libsvtjpegxs.
โญ Options โญ
decomp_vโ set vertical decomposition level.decomp_hโ set horizontal decomposition level.quantizationโ set the quantization algorithm.deadzoneuniform
coding-signsโ enable Signs handling strategy.disablefastfull
coding-sigfโ enable Significance coding.coding-vpredโ enable Vertical Prediction coding.disableno_residualsno_coeffs
๐ง libjxl ๐ง
The libjxl JPEG XL encoder wrapper, obsessed with her honestly ๐
Needs the libjxl headers and library during configuration. You gotta explicitly configure the build with --enable-libjxl.
๐ฅ Options ๐ฅ
The libjxl wrapper supports these:
distanceโ set the target Butteraugli distance. This is a quality setting, bestie: lower distance = higher quality, withdistance=1.0roughly comparable to libjpeg Quality 90 for photographic content. Settingdistance=0.0yields true lossless encoding. Valid values range between0.0and15.0, and sane values rarely exceed5.0. Settingdistance=0.1usually attains transparency for most input. The default is1.0.effortโ set the encoding effort used. Higher effort values produce more consistent quality and usually produce a better quality/bpp curve, at the cost of more CPU time required (your fans will let you know ๐ญ). Valid values range from1to9, and the default is7.modularโ force the encoder to use Modular mode instead of choosing automatically. The default is to use VarDCT for lossy encoding and Modular for lossless. VarDCT is generally superior to Modular for lossy encoding but does not support lossless encoding. Pick your fighter ๐ฅ
๐ libkvazaar ๐
Kvazaar H.265/HEVC encoder, slay ๐ฆ
Needs the libkvazaar headers and library during configuration. You gotta explicitly configure the build with --enable-libkvazaar.
โจ Options โจ
bโ set target video bitrate in bit/s and enable rate control.kvazaar-paramsโ set kvazaar parameters as a list ofname=valuepairs separated by commas (,). See the kvazaar documentation for a list of options.
๐ libopenh264 ๐
Cisco libopenh264 H.264/MPEG-4 AVC encoder wrapper โ a certified classic ๐
This encoder needs the libopenh264 headers and library during configuration. You gotta explicitly configure the build with --enable-libopenh264. The library is detected using pkg-config.
For more info about the library see http://www.openh264.org.
๐ธ Options ๐ธ
These FFmpeg global options affect the configurations of the libopenh264 encoder:
bโ set the bitrate (as a number of bits per second).gโ set the GOP size.maxrateโ set the max bitrate (as a number of bits per second).flags +global_headerโ set global header in the bitstream.slicesโ set the number of slices, used in parallelized encoding. Default value is0. This is only used whenslice_modeis set tofixed.loopfilterโ enable loop filter, if set to1(automatically enabled). To disable, set a value of0.profileโ set profile restrictions. If set to the value ofmain, enable CABAC (set the"SEncParamExt.iEntropyCodingModeFlag"flag to1).max_nal_sizeโ set maximum NAL size in bytes.allow_skip_framesโ allow skipping frames to hit the target bitrate if set to1.
๐ libtheora ๐
The libtheora Theora encoder wrapper, vintage but make it cute ๐
Needs the libtheora headers and library during configuration. You gotta explicitly configure the build with --enable-libtheora.
For more info about the libtheora project see http://www.theora.org/.
โญ Options โญ
These global options get mapped to internal libtheora options, and they affect the quality and the bitrate of the encoded stream:
bโ set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In case VBR (Variable Bit Rate) mode is enabled, this option is ignored. rude but okay ๐flagsโ used to enable constant quality mode (VBR) encoding through theqscaleflag, and to enable the"pass1"and"pass2"modes.gโ set the GOP size.global_qualityโ set the global quality as an integer in lambda units.
Only relevant when VBR mode is enabled with "flags +qscale". The value is converted to QP units by dividing it by FF_QP2LAMBDA, clipped in the [0 - 10] range, and then multiplied by 6.3 to get a value in the native libtheora range [0-63]. A higher value corresponds to a higher quality.
qโ enable VBR mode when set to a non-negative value, and set constant quality value as a double floating point value in QP units.
The value is clipped in the [0-10] range, and then multiplied by 6.3 to get a value in the native libtheora range [0-63].
This option is valid only using the ffmpeg command-line tool. For library interface users, use global_quality. (iykyk โจ)
๐ Examples ๐
- Set maximum constant quality (VBR) encoding with
ffmpeg:
ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
- Use
ffmpegto convert a CBR 1000 kbps Theora video stream:
ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
๐ libvpx ๐
VP8/VP9 format supported through libvpx, the main character of web video fr fr ๐ฅ
Needs the libvpx headers and library during configuration. You gotta explicitly configure the build with --enable-libvpx.
๐ฆ Options ๐ฆ
The following options are supported by the libvpx wrapper. The vpxenc-equivalent options or values are listed in parentheses for easy migration (we love a smooth transition ๐).
To reduce the duplication of documentation, only the private options and some others requiring special attention are documented here. For the documentation of the undocumented generic options, see the Codec Options chapter.
To get more documentation of the libvpx options, invoke the command ffmpeg -h encoder=libvpx, ffmpeg -h encoder=libvpx-vp9 or vpxenc --help. Further information is available in the libvpx API documentation.
b(target-bitrate) โ set bitrate in bits/s. Note that FFmpeg'sboption is expressed in bits/s, while vpxenc'starget-bitrateis in kilobits/s. watch that unit slippage bestie ๐ญg(kf-max-dist)keyint_min(kf-min-dist)qmin(min-q) โ Minimum (Best Quality) Quantizer.qmax(max-q) โ Maximum (Worst Quality) Quantizer. Can be changed per-frame.bufsize(buf-sz,buf-optimal-sz) โ set ratecontrol buffer size (in bits). Note vpxenc's options are specified in milliseconds, and the libvpx wrapper converts this value as follows:"buf-sz = bufsize * 1000 / bitrate","buf-optimal-sz = bufsize * 1000 / bitrate * 5 / 6".rc_init_occupancy(buf-initial-sz) โ set number of bits which should be loaded into the rc buffer before decoding starts. Note vpxenc's option is specified in milliseconds, and the libvpx wrapper converts this value as follows:"rc_init_occupancy * 1000 / bitrate".undershoot-pctโ set datarate undershoot (min) percentage of the target bitrate.overshoot-pctโ set datarate overshoot (max) percentage of the target bitrate.skip_threshold(drop-frame)qcomp(bias-pct)maxrate(maxsection-pct) โ set GOP max bitrate in bits/s. Note vpxenc's option is specified as a percentage of the target bitrate, and the libvpx wrapper converts this value as follows:"(maxrate * 100 / bitrate)".minrate(minsection-pct) โ set GOP min bitrate in bits/s. Note vpxenc's option is specified as a percentage of the target bitrate, and the libvpx wrapper converts this value as follows:"(minrate * 100 / bitrate)".minrate,maxrate,bend-usage=cbrโ"(minrate == maxrate == bitrate)".crf(end-usage=cq,cq-level) โ the constant-rate-factor knob, it lowkey lets you dial in quality directly ๐tune(tune) โ tells the encoder what to optimize for, and these are your choices:psnr(psnr) โ optimize for PSNR numbersssim(ssim) โ optimize for SSIM numbers
quality,deadline(deadline) โ the effort dial โจbestโ use the best quality deadline. Ngl the naming is doing too much here: it's poorly named and quite slow, and you should honestly avoid it because it may give you worse quality output thangood. Yeah. Iconic behavior honestly ๐ญgoodโ use the good quality deadline. This is a good trade-off between speed and quality when used with thecpu-usedoption. This is the one, bestie ๐ซถrealtimeโ use the realtime quality deadline.
speed,cpu-used(cpu-used) โ sets the quality/speed ratio modifier. Higher values speed up the encode at the cost of quality. No cap, you're trading one for the other.nr(noise-sensitivity) โ noise sensitivity setting.static-threshโ sets a change threshold on blocks, below which they will be skipped by the encoder.slices(token-parts) โ โ ๏ธ heads up: FFmpeg'sslicesoption gives the total number of partitions, whilevpxenc'stoken-partsis given aslog2(partitions). Not the same thing, don't get got.max-intra-rateโ sets the maximum I-frame bitrate as a percentage of the target bitrate. A value of0means unlimited.force_key_framesโ literally just"VPX_EFLAG_FORCE_KF".- Alternate reference frame related ๐ฆ โ the whole alt-ref squad:
auto-alt-refโ enable use of alternate reference frames (2-pass only). Values greater than1enable multi-layer alternate reference frames (VP9 only).arnr-maxframesโ set altref noise reduction max frame count.arnr-typeโ set altref noise reduction filter type:backward,forward,centered.arnr-strengthโ set altref noise reduction filter strength.rc-lookahead,lag-in-frames(lag-in-frames) โ set number of frames to look ahead for frametype and ratecontrol.min-gf-intervalโ set minimum golden/alternate reference frame interval (VP9 only).
error-resilientโ enable error resiliency features.sharpnessinteger โ increase sharpness at the expense of lower PSNR. The valid range is[0, 7].ts-parametersโ sets the temporal scalability configuration using a:-separated list ofkey=valuepairs. For example, to specify temporal scalability parameters withffmpeg:
ffmpeg -i INPUT -c:v libvpx -ts-parameters ts_number_layers=3:\
ts_target_bitrate=250,500,1000:ts_rate_decimator=4,2,1:\
ts_periodicity=4:ts_layer_id=0,2,1,2:ts_layering_mode=3 OUTPUT
Below is a brief explanation of each of the parameters, please refer to struct vpx_codec_enc_cfg in vpx/vpx_encoder.h for more details ๐
ts_number_layersโ number of temporal coding layers.ts_target_bitrateโ target bitrate for each temporal layer (in kbps). (bitrate should be inclusive of the lower temporal layer).ts_rate_decimatorโ frame rate decimation factor for each temporal layer.ts_periodicityโ length of the sequence defining frame temporal layer membership.ts_layer_idโ template defining the membership of frames to temporal layers.ts_layering_modeโ (optional) selecting the temporal structure from a set of pre-defined temporal layering modes. Currently supports the following options.0โ no temporal layering flags are provided internally, relies on flags being passed in using"metadata"field in"AVFrame"with following keys:vp8-flagsโ sets the flags passed into the encoder to indicate the referencing scheme for the current frame. Refer to functionvpx_codec_encodeinvpx/vpx_encoder.hfor more details.temporal_idโ explicitly sets the temporal id of the current frame to encode.
2โ two temporal layers.0-1...3โ three temporal layers.0-2-1-2...; with single reference frame.4โ same as option"3", except there is a dependency between the two temporal layer 2 frames within the temporal period.
- VP8-specific options ๐
screen-content-modeโ screen content mode, one of:0(off),1(screen),2(screen with more aggressive rate control).
- VP9-specific options ๐
losslessโ enable lossless mode.tile-columnsโ set number of tile columns to use. Note this is given aslog2(tile_columns). For example,8tile columns would be requested by setting thetile-columnsoption to3.tile-rowsโ set number of tile rows to use. Note this is given aslog2(tile_rows). For example,4tile rows would be requested by setting thetile-rowsoption to2.frame-parallelโ enable frame parallel decodability features.aq-modeโ set adaptive quantization mode (0: off (default),1: variance2: complexity,3: cyclic refresh,4: equator360). Yes that2:is written exactly like that, don't @ me ๐ญcolorspacecolor-space โ set input color space. The VP9 bitstream supports signaling the following colorspaces:rgbโ sRGBbt709โ bt709unspecifiedโ unknownbt470bgโ bt601smpte170mโ smpte170smpte240mโ smpte240bt2020_nclโ bt2020
row-mtboolean โ enable row based multi-threading.tune-contentโ set content type:default(0),screen(1),film(2).corpus-complexityโ Corpus VBR mode is a variant of standard VBR where the complexity distribution midpoint is passed in rather than calculated for a specific clip or chunk. The valid range is[0, 10000].0(default) uses standard VBR.enable-tplboolean โ enable temporal dependency model.ref-frame-configโ using per-frame metadata, set members of the structurevpx_svc_ref_frame_config_tinvpx/vp8cx.hto fine-control referencing schemes and frame buffer management. Use a:-separated list ofkey=valuepairs. For example,
av_dict_set(&av_frame->metadata, "ref-frame-config", \
"rfc_update_buffer_slot=7:rfc_lst_fb_idx=0:rfc_gld_fb_idx=1:rfc_alt_fb_idx=2:rfc_reference_last=0:rfc_reference_golden=0:rfc_reference_alt_ref=0");
rfc_update_buffer_slotโ indicates the buffer slot number to updaterfc_update_lastโ indicates whether to update the LAST framerfc_update_goldenโ indicates whether to update GOLDEN framerfc_update_alt_refโ indicates whether to update ALT_REF framerfc_lst_fb_idxโ LAST frame buffer indexrfc_gld_fb_idxโ GOLDEN frame buffer indexrfc_alt_fb_idxโ ALT_REF frame buffer indexrfc_reference_lastโ indicates whether to reference LAST framerfc_reference_goldenโ indicates whether to reference GOLDEN framerfc_reference_alt_refโ indicates whether to reference ALT_REF framerfc_reference_durationโ indicates frame duration
For more information about libvpx see: <http://www.webmproject.org/>
libvvenc ๐
VVenC H.266/VVC encoder wrapper.
This encoder requires the presence of the libvvenc headers and library during configuration. You need to explicitly configure the build with --enable-libvvenc.
The VVenC project website is at <https://github.com/fraunhoferhhi/vvenc>.
Supported Pixel Formats
VVenC supports only 10-bit color spaces as input. But the internal (encoded) bit depth can be set to 8-bit or 10-bit at runtime. Wild, I know ๐
Options
bโ sets target video bitrate.gโ set the GOP size. Currently support forg=1(Intra only) or default.presetโ set the VVenC preset.levelidcโ set level idc.tierโ set vvc tier.qpโ set constant quantization parameter.suboptboolean โ set subjective (perceptually motivated) optimization. Default is1(on).bitdepth8boolean โ set 8bit coding mode instead of using 10bit. Default is0(off).periodโ set (intra) refresh period in seconds.vvenc-paramsโ set vvenc options using a list ofkey=valuecouples separated by":". Seevvencapp --fullhelporvvencFFapp --fullhelpfor a list of options.
For example, the options might be provided as:
intraperiod=64:decodingrefreshtype=idr:poc0idr=1:internalbitdepth=8
For example the encoding options might be provided with -vvenc-params:
ffmpeg -i input -c:v libvvenc -b 1M -vvenc-params intraperiod=64:decodingrefreshtype=idr:poc0idr=1:internalbitdepth=8 output.mp4
libwebp ๐
libwebp WebP Image encoder wrapper.
libwebp is Google's official encoder for WebP images. It can encode in either lossy or lossless mode. Lossy images are essentially a wrapper around a VP8 frame. Lossless images are a separate codec developed by Google.
Pixel Format
Currently, libwebp only supports YUV420 for lossy and RGB for lossless due to limitations of the format and libwebp. Alpha is supported for either mode. Because of API limitations, if RGB is passed in when encoding lossy or YUV is passed in for encoding lossless, the pixel format will automatically be converted using functions from libwebp. This is not ideal and is done only for convenience. Not me side-eyeing the auto-conversion ๐
Options
-losslessboolean โ enables/disables use of lossless mode. Default is0.-compression_levelinteger โ for lossy, this is a quality/speed tradeoff. Higher values give better quality for a given size at the cost of increased encoding time. For lossless, this is a size/speed tradeoff. Higher values give smaller size at the cost of increased encoding time. More specifically, it controls the number of extra algorithms and compression tools used, and varies the combination of these tools. This maps to themethodoption in libwebp. The valid range is0to6. Default is4.-qualityfloat โ for lossy encoding, this controls image quality. For lossless encoding, this controls the effort and time spent in compression. Range is0to100. Default is75.-presettype โ configuration preset. This does some automatic settings based on the general type of the image.noneโ do not use a preset.defaultโ use the encoder default.pictureโ digital picture, like portrait, inner shotphotoโ outdoor photograph, with natural lightingdrawingโ hand or line drawing, with high-contrast details
iconโ small-sized colorful images ๐จtextโ text-like stuff ๐
๐ libx264, libx264rgb ๐
okay bestie, this is the x264 wrapper โ the H.264/MPEG-4 AVC encoder glow-up ๐ โจ
Heads up though: this encoder needs the libx264 headers AND the library present at configure time, no cap. You have to explicitly configure the build with --enable-libx264. Miss that and it's giving "where is she" ๐ญ
libx264 supports an impressive number of features, including 8x8 and 4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC entropy coding, interlacing (MBAFF), lossless mode, and psy optimizations for detail retention (adaptive quantization, psy-RD, psy-trellis). like, she ate ๐ฅ
Many libx264 encoder options are mapped onto FFmpeg global codec options, while the unique encoder options come through as private options. Also, the x264opts and x264-params private options let you pass a list of key=value tuples exactly as accepted by the libx264 x264_param_parse function. iykyk ๐ซถ
The x264 project website is at <http://www.videolan.org/developers/x264.html>. go say hi ๐ฆ
The libx264rgb encoder is literally the same as libx264, except it accepts packed RGB pixel formats as input instead of YUV. that's the whole vibe check ๐ธ
๐ Supported Pixel Formats ๐
x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at x264's configure time โ so that's a build-time decision, not a runtime one, periodt โญ
โจ Options โจ
The following options are supported by the libx264 wrapper. The x264-equivalent options or values are listed in parentheses for easy migration ๐
To reduce the duplication of documentation, only the private options and some others requiring special attention are documented here. For the documentation of the undocumented generic options, see the Codec Options chapter. (yes, we're delegating, she's busy ๐ )
To get a more accurate and extensive documentation of the libx264 options, invoke the command x264 --fullhelp or consult the libx264 documentation. go straight to the source, bestie ๐
In the list below, note that the x264 option name is shown in parentheses after the libavcodec corresponding name, in case there is a direct mapping. ๐
b(bitrate) โ Set bitrate in bits/s. Important lore: FFmpeg'sboption is expressed in bits/s, while x264'sbitrateis in kilobits/s. do NOT mix those up, it's giving disaster ๐ญbf(bframes) โ Number of B-frames between I and P-frames.g(keyint) โ Maximum GOP size.qmin(qpmin) โ Minimum quantizer scale.qmax(qpmax) โ Maximum quantizer scale.qdiff(qpstep) โ Maximum difference between quantizer scales.qblur(qblur) โ Quantizer curve blur.qcomp(qcomp) โ Quantizer curve compression factor.refs(ref) โ Number of reference frames each P-frame can use. The range is 0-16. ๐ฏlevel(level) โ Set thex264_param_t.i_level_idcvalue in case the value is positive, it is ignored otherwise.
This value can be set using the AVCodecContext API (e.g. by setting the AVCodecContext value directly), and is specified as an integer mapped on a corresponding level (e.g. the value 31 maps to H.264 level IDC 3.1, as defined in the x264_levels table). It is ignored when set to a non positive value.
Alternatively it can be set as a private option, overriding the value set in AVCodecContext, and in this case must be specified as the level IDC identifier (e.g. 3.1), as defined by H.264 Annex A. two ways to say the same thing, pick your fighter ๐ฅ
sc_threshold(scenecut) โ Sets the threshold for the scene change detection.trellis(trellis) โ Performs Trellis quantization to increase efficiency. Enabled by default. โnr(nr) โ Noise reduction.me_range(merange) โ Maximum range of the motion search in pixels.me_method(me) โ Set motion estimation method. Possible values in the decreasing order of speed:dia(dia) /epzs(dia) โ Diamond search with radius 1 (fastest).epzsis an alias fordia.hex(hex) โ Hexagonal search with radius 2.umh(umh) โ Uneven multi-hexagon search.esa(esa) โ Exhaustive search.tesa(tesa) โ Hadamard exhaustive search (slowest). she takes her time ๐
forced-idrโ Normally, when forcing a I-frame type, the encoder can select any type of I-frame. This option forces it to choose an IDR-frame. no negotiating ๐subq(subme) โ Sub-pixel motion estimation method.b_strategy(b-adapt) โ Adaptive B-frame placement decision algorithm. Use only on first-pass. โ ๏ธkeyint_min(min-keyint) โ Minimum GOP size.coderโ Set entropy encoder. Possible values:acโ Enable CABAC.vlcโ Enable CAVLC and disable CABAC. It generates the same effect as x264's--no-cabacoption.
cmpโ Set full pixel motion estimation comparison algorithm. Possible values:chromaโ Enable chroma in motion estimation.sadโ Ignore chroma in motion estimation. It generates the same effect as x264's--no-chroma-meoption.
threads(threads) โ Number of encoding threads. ๐งตthread_typeโ Set multithreading technique. Possible values:sliceโ Slice-based multithreading. It generates the same effect as x264's--sliced-threadsoption.frameโ Frame-based multithreading.
flagsโ Set encoding flags. It can be used to disable closed GOP and enable open GOP by setting it to-cgop. The result is similar to the behavior of x264's--open-gopoption. wild syntax, but ok ๐ซrc_init_occupancy(vbv-init) โ Initial VBV buffer occupancy.preset(preset) โ Set the encoding preset.tune(tune) โ Set tuning of the encoding params.profile(profile) โ Set profile restrictions.fastfirstpassโ Enable fast settings when encoding first pass, when set to1. When set to0, it has the same effect of x264's--slow-firstpassoption.crf(crf) โ Set the quality for constant quality mode.crf_max(crf-max) โ In CRF mode, prevents VBV from lowering quality beyond this point. a little boundary, as a treat ๐qp(qp) โ Set constant quantization rate control method parameter.aq-mode(aq-mode) โ Set AQ method. Possible values:none(0) โ Disabled.variance(1) โ Variance AQ (complexity mask).autovariance(2) โ Auto-variance AQ (experimental). โ๏ธ
aq-strength(aq-strength) โ Set AQ strength, reduce blocking and blurring in flat and textured areas.psyโ Use psychovisual optimizations when set to1. When set to0, it has the same effect as x264's--no-psyoption.psy-rd(psy-rd) โ Set strength of psychovisual optimization, inpsy-rd:psy-trellisformat.rc-lookahead(rc-lookahead) โ Set number of frames to look ahead for frametype and ratecontrol. ๐weightbโ Enable weighted prediction for B-frames when set to1. When set to0, it has the same effect as x264's--no-weightboption.weightp(weightp) โ Set weighted prediction method for P-frames. Possible values:none(0) โ Disabled.simple(1) โ Enable only weighted refs.smart(2) โ Enable both weighted refs and duplicates. ๐ง
ssim(ssim) โ Enable calculation and printing SSIM stats after the encoding.intra-refresh(intra-refresh) โ Enable the use of Periodic Intra Refresh instead of IDR frames when set to1.avcintra-class(class) โ Configure the encoder to generate AVC-Intra. Valid values are50,100and200. 5๏ธโฃ0๏ธโฃbluray-compat(bluray-compat) โ Configure the encoder to be compatible with the bluray standard. It is a shorthand for settingbluray-compat=1 force-cfr=1. shorthand queen ๐ฟb-bias(b-bias) โ Set the influence on how often B-frames are used.b-pyramid(b-pyramid) โ Set method for keeping of some B-frames as references. Possible values:none(none) โ Disabled.strict(strict) โ Strictly hierarchical pyramid.normal(normal) โ Non-strict (not Blu-ray compatible). โ ๏ธ
mixed-refsโ Enable the use of one reference per partition, as opposed to one reference per macroblock when set to1. When set to0, it has the same effect as x264's--no-mixed-refsoption.8x8dctโ Enable adaptive spatial transform (high profile 8x8 transform) when set to1. When set to0, it has the same effect as x264's--no-8x8dctoption.fast-pskipโ Enable early SKIP detection on P-frames when set to1. When set to0, it has the same effect as x264's--no-fast-pskipoption.aud(aud) โ Enable use of access unit delimiters when set to1.mbtreeโ Enable use macroblock tree ratecontrol when set to1. When set to0, it has the same effect as x264's--no-mbtreeoption. ๐ณdeblock(deblock) โ Set loop filter parameters, inalpha:betaform.cplxblur(cplxblur) โ Set fluctuations reduction in QP (before curve compression).partitions(partitions) โ Set partitions to consider as a comma-separated list of values. Possible values in the list:p8x8โ 8x8 P-frame partition.p4x4โ 4x4 P-frame partition.b8x8โ 4x4 B-frame partition.i8x8โ 8x8 I-frame partition.i4x4โ 4x4 I-frame partition. (Enablingp4x4requiresp8x8to be enabled. Enablingi8x8requires adaptive spatial transform (8x8dctoption) to be enabled.) โ ๏ธ read that twice bestienone(none) โ Do not consider any partitions.all(all) โ Consider every partition. all of them, greedy ๐
direct-pred(direct) โ Set direct MV prediction mode. Possible values:none(none) โ Disable MV prediction.spatial(spatial) โ Enable spatial predicting.temporal(temporal) โ Enable temporal predicting.auto(auto) โ Automatically decided. she'll figure it out ๐ง
slice-max-size(slice-max-size) โ Set the limit of the size of each slice in bytes. If not specified but RTP payload size (ps) is specified, that is used. ๐stats(stats) โ Set the file name for multi-pass stats.nal-hrd(nal-hrd) โ Set signal HRD information (requiresvbv-bufsizeto be set). Possible values:none(none) โ Disable HRD information signaling.vbr(vbr) โ Variable bit rate.cbr(cbr) โ Constant bit rate (not allowed in MP4 container). ๐ซ
x264optsopts /x264-paramsopts โ Override the x264 configuration using a:-separated list ofkey=valueoptions.
The argument for both options is a list of key=value couples separated by ":". With x264opts the value can be omitted, and the value 1 is assumed in that case. little shortcut, love that for us ๐
Okay so real talk about separators for a sec ๐ โ for filter and psy-rd option values that use ":" as a separator themselves, use "," instead. They've accepted that too since forever ago, but it's kept undocumented for some reason ๐ (iykyk).
So like, the options might be provided as:
level=30:bframes=0:weightp=0:cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:no-fast-pskip=1:subq=6:8x8dct=0:trellis=0
And say you wanna specify libx264 encoding options with ffmpeg, bestie, you do:
ffmpeg -i foo.mpg -c:v libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
To get the complete list of the libx264 options, invoke the command x264 --fullhelp or consult the libx264 documentation โจ (yes, go read the docs, she's worth it).
a53ccboolean โ Import closed captions (which must be ATSC compatible format) into output. Only thempeg2andh264decoders provide these. Default is1(on). ๐udu_seiboolean โ Import user data unregistered SEI if available into output. Default is0(off).mb_infoboolean โ Set mb_info data throughAVFrameSideData, only useful when used from the API. Default is0(off). (API girlies only, lowkey.)
Encoding ffpresets for common usages are provided so they can be used with the general presets system (e.g. passing the pre option) ๐ฆ.
โจ libx265 โจ
x265 H.265/HEVC encoder wrapper. She's iconic, she's efficient ๐
This encoder requires the presence of the libx265 headers and library during configuration. You need to explicitly configure the build with --enable-libx265.
Options
bโ Sets target video bitrate.bfโ listed all on her own with no description, just vibing ๐ซถgโ Set the GOP size.keyint_minโ Minimum GOP size.refsโ Number of reference frames each P-frame can use. The range is from1-16.presetโ Set the x265 preset.tuneโ Set the x265 tune parameter.profileโ Set profile restrictions.crfโ Set the quality for constant quality mode.qpโ Set constant quantization rate control method parameter.qminโ Minimum quantizer scale.qmaxโ Maximum quantizer scale.qdiffโ Maximum difference between quantizer scales.qblurโ Quantizer curve blur.qcompโ Quantizer curve compression factor.i_qfactorโ (no description, she's a mystery, respect it ๐)b_qfactorโ (same, no description)forced-idrโ Normally, when forcing a I-frame type, the encoder can select any type of I-frame. This option forces it to choose an IDR-frame. ๐ฅx265-statsโ Specify the file name for 2-pass stats. This is set automatically when using the-passlogfileoption.udu_seiboolean โ Import user data unregistered SEI if available into output. Default is0(off).x265-paramsโ Set x265 options using a list ofkey=valuecouples separated by ":". Seex265 --helpfor a list of options.
So like, to specify libx265 encoding options with -x265-params:
ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
๐ libxavs2 ๐
xavs2 AVS2-P2/IEEE1857.4 encoder wrapper. Niche? Maybe. Slay? Absolutely ๐
This encoder requires the presence of the libxavs2 headers and library during configuration. You need to explicitly configure the build with --enable-libxavs2.
The following standard libavcodec options are used:
b/bit_rateg/gop_sizebf/max_b_frames
The encoder also has its own specific options:
Options
lcu_row_threadsโ Set the number of parallel threads for rows from1to8(default5).initial_qpโ Set the xavs2 quantization parameter from1to63(default34). This is used to set the initial qp for the first frame.qpโ Set the xavs2 quantization parameter from1to63(default34). This is used to set the qp value under constant-QP mode.max_qpโ Set the max qp for rate control from1to63(default55).min_qpโ Set the min qp for rate control from1to63(default20).speed_levelโ Set the Speed level from0to9(default0). Higher is better but slower. ๐ญ (the eternal tradeoff, bestie)log_levelโ Set the log level from-1to3(default0).-1: none,0: error,1: warning,2: info,3: debug.xavs2-paramsโ Set xavs2 options using a list ofkey=valuecouples separated by ":".
Example time, to specify libxavs2 encoding options with -xavs2-params:
ffmpeg -i input -c:v libxavs2 -xavs2-params RdoqLevel=0 output.avs2
๐ฆ libxeve ๐ฆ
eXtra-fast Essential Video Encoder (XEVE) MPEG-5 EVC encoder wrapper. The xeve-equivalent options or values are listed in parentheses for easy migration โจ (thoughtful queen behavior).
This encoder requires the presence of the libxeve headers and library during configuration. You need to explicitly configure the build with --enable-libxeve.
Many libxeve encoder options are mapped to FFmpeg global codec options, while unique encoder options are provided through private options. Additionally thexeve-paramsprivate options allows one to pass a list ofkey=valuetuples as accepted by the libxeveparse_xeve_paramsfunction.
The xeve project website is at <https://github.com/mpeg5/xeve>.
Options
The following options are supported by the libxeve wrapper. The xeve-equivalent options or values are listed in parentheses for easy migration.
To reduce the duplication of documentation, only the private options and some others requiring special attention are documented here. For the documentation of the undocumented generic options, see the Codec Options chapter.
To get a more accurate and extensive documentation of the libxeve options, invoke the command xeve_app --help or consult the libxeve documentation.
b(bitrate) โ Set target video bitrate in bits/s. Note that FFmpeg'sboption is expressed in bits/s, while xeve's bitrate is in kilobits/s. โ ๏ธ (units will get you, fr fr)bf(bframes) โ Set the maximum number of B frames (1,3,7,15).g(keyint) โ Set the GOP size (I-picture period).preset(preset) โ Set the xeve preset. Set the encoder preset value to determine encoding speed [fast,medium,slow,placebo].tune(tune) โ Set the encoder tune parameter [psnr,zerolatency].profile(profile) โ Set the encoder profile [0: baseline;1: main].crf(crf) โ Set the quality for constant quality mode. Constant rate factor<10..49>[default:32].qp(qp) โ Set constant quantization rate control method parameter. Quantization parameter qp<0..51>[default:32].threads(threads) โ Force to use a specific number of threads.
๐ libxvid ๐
Xvid MPEG-4 Part 2 encoder wrapper. Old school but she still eats ๐
This encoder requires the presence of the libxvidcore headers and library during configuration. You need to explicitly configure the build with --enable-libxvid --enable-gpl.
The native mpeg4 encoder supports the MPEG-4 Part 2 format, so users can encode to this format without this library. (No cap โ you might not even need her!)
Options
The following options are supported by the libxvid wrapper. Some of the following options are listed but are not documented, and correspond to shared codec options. See the Codec Options chapter for their documentation. The other shared options which are not listed have no effect for the libxvid encoder.
bโ listed, shared codec option, not documented here.gโ same deal.qminโ same deal.qmaxโ same deal.mpeg_quantโ same deal.threadsโ same deal.bfโ same deal.b_qfactorโ same deal.b_qoffsetโ same deal.flagsโ Set specific encoding flags. Possible values:mv4โ Use four motion vector by macroblock.aicโ Enable high quality AC prediction.grayโ Only encode grayscale.qpelโ Enable quarter-pixel motion compensation.cgopโ Enable closed GOP.global_headerโ Place global headers in extradata instead of every keyframe.
gmcโ Enable the use of global motion compensation (GMC). Default is0(disabled).me_qualityโ Set motion estimation quality level. Possible values in decreasing order of speed and increasing order of quality:0โ Use no motion estimation (default).1,2โ Enable advanced diamond zonal search for 16x16 blocks and half-pixel refinement for 16x16 blocks.3,4โ Enable all of the things described above, plus advanced diamond zonal search for 8x8 blocks and half-pixel refinement for 8x8 blocks, also enable motion estimation on chroma planes for P and B-frames.5,6โ Enable all of the things described above, plus extended 16x16 and 8x8 blocks search.
mbdโ Set macroblock decision algorithm. Possible values in the increasing order of quality:simpleโ Use macroblock comparing function algorithm (default).bitsโ Enable rate distortion-based half pixel and quarter pixel refinement for 16x16 blocks.rdโ Enable all of the things described above, plus rate distortion-based half pixel and quarter pixel refinement for 8x8 blocks, and rate distortion-based search using square pattern.
lumi_aqโ Enable lumi masking adaptive quantization when set to1. Default is0(disabled).variance_aqโ Enable variance adaptive quantization when set to1. Default is0(disabled).
When combined with lumi_aq, the resulting quality will not be better than any of the two specified individually. In other words, the resulting quality will be the worse one of the two effects. ๐ญ๐ (two great tastes that do NOT taste great together)
trellisโ Set rate-distortion optimal quantization.ssimโ Set structural similarity (SSIM) displaying method. Possible values:offโ Disable displaying of SSIM information.avgโ Output average SSIM at the end of encoding to stdout. The format of showing the average SSIM is:
Average SSIM: %f
For users who are not familiar with C, %f means a float number, or a decimal (e.g. 0.939232).
frameโ Output both per-frame SSIM data during encoding and average SSIM at the end of encoding to stdout. The format of per-frame information is:
SSIM: avg: %1.3f min: %1.3f max: %1.3f
For users who are not familiar with C, %1.3f means a float number rounded to 3 digits after the dot (e.g. 0.932).
ssim_accโ Set SSIM accuracy. Valid options are integers within the range of0-4, while0gives the most accurate result and4computes the fastest.
โญ MediaCodec โญ
MediaCodec encoder wrapper enables hardware-accelerated video encoding on Android device ๐ซถ๐ฑ It supports H.264, H.265 (HEVC), VP8, VP9, MPEG-4, and AV1 encoding (whether works or not is device dependent). Yeah โ device dependent โ so your mileage may absolutely vary, bestie ๐
Okay so bestie, Android gives you two sets of APIs: Java MediaCodec and NDK MediaCodec. The MediaCodec encoder wrapper supports both. ๐ซถ Note that the NDK MediaCodec API operates without requiring a JVM, but may fail to function outside the JVM environment due to dependencies on system framework services, particularly after Android 15. ๐
Here are the knobs ๐ :
ndk_codecboolean โ Use the NDK-based MediaCodec API instead of the Java API. Enabled by default ifav_jni_get_java_vm()returnNULL.ndk_asyncboolean โ Use NDK MediaCodec in async mode. Async mode has less overhead than poll in a loop in sync mode. The drawback of async mode isAV_CODEC_FLAG_GLOBAL_HEADERdoesn't work (useextract_extradatabsf when necessary). It doesn't work and will be disabled automatically on devices below Android 8.0.codec_namestring โ A codec type can have multiple implementations on a single device, this option specify which backend to use (via MediaCodeccreateCodecByNameAPI). It'sNULLby default, and encoder is created bycreateEncoderByType.bitrate_modeinteger โ Possible values:cqโ Constant quality modevbrโ Variable bitrate modecbrโ Constant bitrate modecbr_fdโ Constant bitrate mode with frame drops
pts_as_dtsboolean โ Use PTS as DTS. This is a workaround since MediaCodec API doesn't provide decoding timestamp. It is enabled automatically if B frame is 0.operating_rateinteger โ The desired operating rate that the codec will need to operate at, zero for unspecified. This is used for cases like high-speed/slow-motion video capture, where the video encoder format contains the target playback rate (e.g. 30fps), but the component must be able to handle the high operating capture rate (e.g. 240fps). This rate will be used by codec for resource planning and setting the operating points.qp_i_mininteger โ Minimum quantization parameter for I frame.qp_p_mininteger โ Minimum quantization parameter for P frame.qp_b_mininteger โ Minimum quantization parameter for B frame.qp_i_maxinteger โ Maximum quantization parameter for I frame.qp_p_maxinteger โ Maximum quantization parameter for P frame.qp_b_maxinteger โ Maximum quantization parameter for B frame.
๐ฌ MediaFoundation
The following wrappers for encoders in the MediaFoundation framework are available โ and yes, the original list is giving exactly this:
*<h264_mf>
*<hevc_mf>
*<av1_mf>
These support both software and hardware encoding. โจ
Video encoders can take input in either of nv12 or yuv420p form (some encoders support both, some support only either - in practice, nv12 is the safer choice, especially among HW encoders).
Hardware-accelerated encoding requires D3D11, including hardware scaling capabilities through the scale_d3d11 filter. ๐ฅ
To list all available options for the MediaFoundation encoders, use:
ffmpeg -h encoder=<encoder> e.g. ffmpeg -h encoder=h264_mf
Options
rate_controlโ Select rate control mode. Available modes:defaultโ Default modecbrโ CBR modepc_vbrโ Peak constrained VBR modeu_vbrโ Unconstrained VBR modequalityโ Quality modeld_vbrโ Low delay VBR mode (requires Windows 8+)g_vbrโ Global VBR mode (requires Windows 8+)gld_vbrโ Global low delay VBR mode (requires Windows 8+)
scenarioโ Select usage scenario. Available scenarios:defaultโ Default scenariodisplay_remotingโ Display remoting scenariovideo_conferenceโ Video conference scenarioarchiveโ Archive scenariolive_streamingโ Live streaming scenariocamera_recordโ Camera record scenariodisplay_remoting_with_feature_mapโ Display remoting with feature map scenario
qualityโ Set encoding quality (0-100).-1means default quality.hw_encodingโ Force hardware encoding (0-1). Default is0(disabled).
Examples
Hardware encoding:
ffmpeg -i input.mp4 -c:v h264_mf -hw_encoding 1 output.mp4
Hardware-accelerated decoding with hardware encoding:
ffmpeg -hwaccel d3d11va -i input.mp4 -c:v h264_mf -hw_encoding 1 output.mp4
Hardware-accelerated decoding, HW scaling and encoding with quality setting:
ffmpeg -hwaccel d3d11va -hwaccel_output_format d3d11 -i input.mp4 -vf scale_d3d11=1920:1080 -c:v hevc_mf -hw_encoding 1 -quality 80 output.mp4
๐จ Microsoft RLE
Microsoft RLE aka MSRLE encoder. Only 8-bit palette mode supported. Compatible with Windows 3.1 and Windows 95. ๐ฅ๏ธ
Options
ginteger โ Keyframe interval. A keyframe is inserted at least every"-g"frames, sometimes sooner.
๐ผ mpeg2
MPEG-2 video encoder.
Options
profileโ Select the mpeg2 profile to encode:422highssโ Spatially Scalablesnrโ SNR Scalablemainsimple
levelโ Select the mpeg2 level to encode:highhigh1440mainlow
seq_disp_extinteger โ Specifies if the encoder should write asequence_display_extensionto the output.-1,autoโ Decide automatically to write it or not (this is the default) by checking if the data to be written is different from the default or unspecified values.0,neverโ Never write it.1,alwaysโ Always write it.
video_formatinteger โ Specifies thevideo_formatwritten into the sequence display extension indicating the source of the video pictures. The default is unspecified, can becomponent,pal,ntsc,secamormac. For maximum compatibility, usecomponent.a53ccboolean โ Import closed captions (which must be ATSC compatible format) into output. Default is1(on).
๐ผ๏ธ png
PNG image encoder.
Options
compression_levelโ Sets the compression level, from0to9(default)
Private options
dpiinteger โ Set physical density of pixels, in dots per inch, unset by defaultdpminteger โ Set physical density of pixels, in dots per meter, unset by defaultpredmethod โ Set prediction method (none,sub,up,avg,paeth,mixed), default ispaeth
๐ ProRes
Apple ProRes encoder.
FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder. The used encoder can be chosen with the "-vcodec" option.
Private Options for prores-ks
profileinteger โ Select the ProRes profile to encodeproxyltstandardhq44444444xq
quant_matinteger โ Select quantization matrix.autodefaultproxyltstandardhq
If set to auto, the matrix matching the profile will be picked. If not set, the matrix providing the highest quality, default, will be picked.
bits_per_mbinteger โ How many bits to allot for coding one macroblock. Different profiles use between200and2400bits per macroblock, the maximum is8000.mbs_per_sliceinteger โ Number of macroblocks in each slice (1-8); the default value (8) should be good in almost all situations.vendorstring โ Override the 4-byte vendor ID. A custom vendor ID likeapl0would claim the stream was produced by the Apple encoder.alpha_bitsinteger โ Specify number of bits for alpha component. Possible values are0,8and16. Use0to disable alpha plane coding.
Speed considerations
In the default mode of operation the encoder has to honor frame constraints (i.e. not produce frames with size bigger than requested) while still making output picture as good as possible. A frame containing a lot of small details is harder to compress and the encoder would spend more time searching for appropriate quantizers for each slice. ๐ญ
Setting a higher bits_per_mb limit will improve the speed.
For the fastest encoding speed set the qscale parameter (4 is the recommended value) and do not set a size constraint.
โก QSV Encoders
The family of Intel QuickSync Video encoders (MPEG-2, H.264, HEVC, JPEG/MJPEG, VP9, AV1)
Ratecontrol Method
The ratecontrol method is selected as follows:
- When
global_qualityis specified, a quality-based mode is used. Specifically this means eitherCQP- constant quantizer scale, when theqscalecodec flag is also set (the-qscaleffmpeg option).LA_ICQ- intelligent constant quality with lookahead, when thelook_aheadoption is also set.ICQ-- intelligent constant quality otherwise. For the ICQ modes, global quality range is1to51, with1being the best quality.
- Otherwise when the desired average bitrate is specified with the
boption, a bitrate-based mode is used.LA- VBR with lookahead, when thelook_aheadoption is specified.VCM- video conferencing mode, when thevcmoption is set.CBR- constant bitrate, whenmaxrateis specified and equal to the average bitrate.VBR- variable bitrate, whenmaxrateis specified, but is higher than the average bitrate.AVBR- average VBR mode, whenmaxrateis not specified, bothavbr_accuracyandavbr_convergenceare set to non-zero. This mode is available for H264 and HEVC on Windows.
- Otherwise the default ratecontrol method
CQPis used.
Note that depending on your system, a different mode than the one you specified may be selected by the encoder. Set the verbosity level to verbose or higher to see the actual settings used by the QSV runtime. ๐
Global Options -> MSDK Options
Additional libavcodec global options are mapped to MSDK options as follows:
g/gop_size->GopPicSizebf/max_b_frames+1->GopRefDistrc_init_occupancy/rc_initial_buffer_occupancy->InitialDelayInKBslices->NumSlicerefs->NumRefFrameb_strategy/b_frame_strategy->BRefTypecgop/CLOSED_GOPcodec flag ->GopOptFlag- For the CQP mode, the
i_qfactor/i_qoffsetandb_qfactor/b_qoffsetset the difference between QPP and QPI, and QPP and QPB respectively. - Setting the
coderoption to the valuevlcwill make the H.264 encoder use CAVLC instead of CABAC.
Common Options
Following options are used by all qsv encoders.
async_depthโ tells the app how many async operations it can fire off before it actually has to stop and sync the result. Set it to zero and the value justโฆ isn't specified. default vibes only โจpresetโ the speed-vs-quality dial, listing out a whole range of choices fromveryfast(= best speed) all the way toveryslow(= best quality). Pick your fighter:veryfastfasterfastmediumslowslowerveryslow
forced_idrโ forces I frames to be IDR frames. no negotiation ๐low_powerโ for encoders, flip this flag to ON to reduce power consumption and GPU usage. your laptop's fans will literally thank you ๐ซถ
โก Runtime Options โก
okay so these are the ones you can actually use during qsv encoding, mid-vibe, no restart needed:
global_quality,i_quant_factor,i_quant_offset,b_quant_factor,b_quant_offsetโ supported inh264_qsvandhevc_qsv. change these values to reset the qsv codec's qp configuration. ๐ฅmax_frame_sizeโ supported inh264_qsvandhevc_qsv. change this value to reset the qsv codec's MaxFrameSize configuration.gop_sizeโ change this value to reset the qsv codec's gop configuration.int_ref_type,int_ref_cycle_size,int_ref_qp_delta,int_ref_cycle_distโ supported inh264_qsvandhevc_qsv. change these values to reset the qsv codec's Intra Refresh configuration.qmax,qmin,max_qp_i,min_qp_i,max_qp_p,min_qp_p,max_qp_b,min_qp_bโ supported inh264_qsv. change these values to reset the qsv codec's max/min qp configuration.low_delay_brcโ supported inh264_qsv,hevc_qsvandav1_qsv. change this value to reset the qsv codec'slow_delay_brcconfiguration.framerateโ change this value to reset the qsv codec's framerate configuration.bit_rate,rc_buffer_size,rc_initial_buffer_occupancy,rc_max_rateโ change these values to reset the qsv codec's bitrate control configuration.pic_timing_seiโ supported inh264_qsvandhevc_qsv. change this value to reset the qsv codec'spic_timing_seiconfiguration.qsv_paramsโ sets QSV encoder parameters as a colon-separated list of key-value pairs. ๐
the qsv_params should be formatted as "key1=value1:key2=value2:...".
these parameters get passed directly to the underlying Intel Quick Sync Video (QSV) encoder using the MFXSetParameter function. no middleman, no cap.
example:
ffmpeg -i input.mp4 -c:v h264_qsv -qsv_params "CodingOption1=1:CodingOption2=2" output.mp4
this option gives you fine-grained control over all the various encoder-specific settings the QSV encoder provides. you're basically in the driver's seat now ๐
๐ H264 options ๐
these are the ones used by h264_qsv, and there are so many of them, buckle up bestie:
extbrcโ extended bitrate control.recovery_point_seiโ set this flag to insert the recovery point SEI message at the beginning of every intra refresh cycle.rdoโ enable rate distortion optimization.max_frame_sizeโ maximum encoded frame size in bytes.max_frame_size_iโ maximum encoded frame size for I frames in bytes. if this value is set as larger than zero, then for I frames the value set bymax_frame_sizeis ignored. it said what it said ๐max_frame_size_pโ maximum encoded frame size for P frames in bytes. if this value is set as larger than zero, then for P frames the value set bymax_frame_sizeis ignored.max_slice_sizeโ maximum encoded slice size in bytes.bitrate_limitโ toggle bitrate limitations. modifies bitrate to be in the range imposed by the QSV encoder. setting this flag off may lead to violation of HRD conformance. mind that specifying bitrate below the QSV encoder range might significantly affect quality. if on, this option takes effect in non-CQP modes: if bitrate is not in the range imposed by the QSV encoder, it will be changed to be in the range.
โ ๏ธ fr fr, turning this off can break HRD conformance. don't say nobody warned you ๐
mbbrcโ setting this flag enables macroblock level bitrate control that generally improves subjective visual quality. enabling this flag may have negative impact on performance and objective visual quality metric. trade-offs, bestie, trade-offs ๐ญlow_delay_brcโ setting this flag turns on or off the LowDelayBRC feature in the qsv plugin, which provides more accurate bitrate control to minimize the variance of bitstream size frame by frame. value:-1-default0-off1-onadaptive_iโ this flag controls insertion of I frames by the QSV encoder. turn ON this flag to allow changing of frame type from P and B to I.adaptive_bโ this flag controls changing of frame type from B to P.p_strategyโ enable P-pyramid:0-default1-simple2-pyramid (bf need to be set to0).b_strategyโ this option controls usage of B frames as reference.dblk_idcโ this option disables deblocking. it has value in range0~2.cavlcโ if set, CAVLC is used; if unset, CABAC is used for encoding.vcmโ video conferencing mode, please see ratecontrol method.idr_intervalโ distance (in I-frames) between IDR frames.pic_timing_seiโ insert picture timing SEI withpic_struct_syntaxelement.single_sei_nal_unitโ put all the SEI messages into one NALU.max_dec_frame_bufferingโ maximum number of frames buffered in the DPB.look_aheadโ use VBR algorithm with look ahead.look_ahead_depthโ depth of look ahead in number frames.look_ahead_downsamplingโ downscaling factor for the frames saved for the lookahead analysis:unknownautooff2x4x
int_ref_typeโ specifies intra refresh type. the major goal of intra refresh is improvement of error resilience without significant impact on encoded bitstream size caused by I frames. the SDK encoder achieves this by encoding part of each frame in the refresh cycle using intra MBs.nonemeans no refresh.verticalmeans vertical refresh, by column of MBs.horizontalmeans horizontal refresh, by rows of MBs.slicemeans horizontal refresh by slices without overlapping. in case ofslice,in_ref_cycle_sizeis ignored. to enable intra refresh, B frame should be set to0. the way this option has lore is unreal ๐int_ref_cycle_sizeโ specifies number of pictures within the refresh cycle starting from2.0and1are invalid values. periodt.int_ref_qp_deltaโ specifies QP difference for inserted intra MBs. this is a signed value in[-51, 51]range if target encoding bit-depth for luma samples is 8, and this range is[-63, 63]for 10 bit-depth or[-75, 75]for 12 bit-depth respectively.int_ref_cycle_distโ distance between the beginnings of the intra-refresh cycles in frames.profileโ pick one:unknownbaselinemainhigh
a53ccโ use A53 Closed Captions (if available).audโ insert the Access Unit Delimiter NAL.mfmodeโ Multi-Frame Mode:offauto
repeat_ppsโ repeat pps for every frame.max_qp_iโ maximum video quantizer scale for I frame.min_qp_iโ minimum video quantizer scale for I frame.max_qp_pโ maximum video quantizer scale for P frame.min_qp_pโ minimum video quantizer scale for P frame.max_qp_bโ maximum video quantizer scale for B frame.min_qp_bโ minimum video quantizer scale for B frame.scenarioโ provides a hint to the encoder about the scenario for the encoding session:unknowndisplayremotingvideoconferencearchivelivestreamingcameracapturevideosurveillancegamestreamingremotegaming
avbr_accuracyโ accuracy of the AVBR ratecontrol (unit of tenth of percent).avbr_convergenceโ convergence of the AVBR ratecontrol (unit of 100 frames).
the parameters avbr_accuracy and avbr_convergence are for the average variable bitrate control (AVBR) algorithm. the algorithm focuses on overall encoding quality while meeting the specified bitrate, target_bitrate, within the accuracy range avbr_accuracy, after a avbr_Convergence period. this method does not follow HRD and the instant bitrate is not capped or padded. iykyk ๐ธ
skip_frameโ use per-frame metadata"qsv_skip_frame"to skip a frame when encoding. this option defines the usage of that metadata:no_skipโ frame skipping is disabled.insert_dummyโ encoder inserts into the bitstream a frame where all macroblocks are encoded as skipped.insert_nothingโ similar toinsert_dummy, but the encoder inserts nothing into the bitstream. the skipped frames are still used in brc. for example, gop still include skipped frames, and the frames after skipped frames will be larger in size.brc_onlyโskip_framemetadata indicates the number of missed frames before the current frame.
๐ HEVC Options ๐
and these are the ones used by hevc_qsv โ yes there's overlap, yes they're still all listed, we don't skip ๐
extbrcโ extended bitrate control.recovery_point_seiโ set this flag to insert the recovery point SEI message at the beginning of every intra refresh cycle.rdoโ enable rate distortion optimization.max_frame_sizeโ maximum encoded frame size in bytes.max_frame_size_iโ maximum encoded frame size for I frames in bytes. if this value is set as larger than zero, then for I frames the value set bymax_frame_sizeis ignored.max_frame_size_pโ maximum encoded frame size for P frames in bytes. if this value is set as larger than zero, then for P frames the value set bymax_frame_sizeis ignored.max_slice_sizeโ maximum encoded slice size in bytes.mbbrcโ setting this flag enables macroblock level bitrate control that generally improves subjective visual quality. enabling this flag may have negative impact on performance and objective visual quality metric.low_delay_brcโ setting this flag turns on or off the LowDelayBRC feature in the qsv plugin, which provides more accurate bitrate control to minimize the variance of bitstream size frame by frame. value:-1-default0-off1-onadaptive_iโ this flag controls insertion of I frames by the QSV encoder. turn ON this flag to allow changing of frame type from P and B to I.adaptive_bโ this flag controls changing of frame type from B to P.p_strategyโ enable P-pyramid:0-default1-simple2-pyramid (bf need to be set to0).b_strategyโ this option controls usage of B frames as reference.dblk_idcโ this option disables deblocking. it has value in range0~2.idr_intervalโ distance (in I-frames) between IDR frames:begin_onlyโ output an IDR-frame only at the beginning of the stream.
load_pluginโ a user plugin you wanna load up in an internal session โจnonehevc_swhevc_hw
load_pluginsโ a:-separated list of hexadecimal plugin UIDs to load in an internal session. lowkey a whole plugin haul ๐look_ahead_depthโ depth of look ahead, in number of frames. only available when theextbrcoption is enabled (so like, turn that on first bestie).profileโ sets the encoding profile (sccrequireslibmfx >= 1.32).unknownmainmain10mainsprextscc
tierโ sets the encoding tier (onlylevel >= 4can support high tier, no cap). this option only takes effect when theleveloption is specified, so don't skip it and expect magic ๐mainhigh
gpbโ1: GPB (generalized P/B frame)0: regular P frame.
tile_colsโ number of columns for tiled encoding.tile_rowsโ number of rows for tiled encoding.audโ insert the Access Unit Delimiter NAL. little punctuation mark for your stream ๐pic_timing_seiโ insert picture timing SEI withpic_struct_syntaxelement.transform_skipโ turn this option ON to enable transformskip. it's supported on platforms equal or newer than ICL.int_ref_typeโ specifies intra refresh type. the major goal of intra refresh is improvement of error resilience without significant impact on encoded bitstream size caused by I frames. the SDK encoder achieves this by encoding part of each frame in the refresh cycle using intra MBs.nonemeans no refresh.verticalmeans vertical refresh, by column of MBs.horizontalmeans horizontal refresh, by rows of MBs.slicemeans horizontal refresh by slices without overlapping. in the case ofslice,in_ref_cycle_sizeis ignored. to enable intra refresh, B frame should be set to0โ ๏ธint_ref_cycle_sizeโ specifies number of pictures within a refresh cycle, starting from2.0and1are invalid values, periodt.int_ref_qp_deltaโ specifies QP difference for inserted intra MBs. this is a signed value in[-51, 51]range if the target encoding bit-depth for luma samples is 8, and this range is[-63, 63]for 10 bit-depth or[-75, 75]for 12 bit-depth respectively. precision queen ๐int_ref_cycle_distโ distance between the beginnings of the intra-refresh cycles, in frames.max_qp_iโ maximum video quantizer scale for I frame.min_qp_iโ minimum video quantizer scale for I frame.max_qp_pโ maximum video quantizer scale for P frame.min_qp_pโ minimum video quantizer scale for P frame.max_qp_bโ maximum video quantizer scale for B frame.min_qp_bโ minimum video quantizer scale for B frame.scenarioโ gives the encoder a lil hint about the scenario for the encoding session ๐ซถunknowndisplayremotingvideoconferencearchivelivestreamingcameracapturevideosurveillancegamestreamingremotegaming
avbr_accuracyโ accuracy of the AVBR rate control (unit of tenth of percent).avbr_convergenceโ convergence of the AVBR rate control (unit of 100 frames).
okay so the parametersavbr_accuracyandavbr_convergenceare for the average variable bitrate control (AVBR) algorithm. the algorithm focuses on overall encoding quality while meeting the specified bitrate,target_bitrate, within the accuracy rangeavbr_accuracy, after anavbr_Convergenceperiod. this method does not follow HRD and the instant bitrate is not capped or padded. no cap, literally ๐งข
skip_frameโ use per-frame metadata"qsv_skip_frame"to skip a frame when encoding. this option defines the usage of this metadata.no_skipโ frame skipping is disabled.insert_dummyโ encoder inserts into the bitstream a frame where all macroblocks are encoded as skipped.insert_nothingโ similar toinsert_dummy, but the encoder inserts nothing into the bitstream. the skipped frames are still used in brc. for example, gop still includes skipped frames, and the frames after skipped frames will be larger in size ๐brc_onlyโskip_framemetadata indicates the number of missed frames before the current frame.
MPEG2 Options
these options are used by mpeg2_qsv ๐ฌ
profileunknownsimplemainhigh
VP9 Options
these options are used by vp9_qsv ๐ฆ
profileunknownprofile0profile1profile2profile3
tile_colsโ number of columns for tiled encoding (requireslibmfx >= 1.29).tile_rowsโ number of rows for tiled encoding (requireslibmfx >= 1.29).
AV1 Options
these options are used by av1_qsv (requires libvpl) ๐
profileunknownmain
tile_colsโ number of columns for tiled encoding.tile_rowsโ number of rows for tiled encoding.adaptive_iโ this flag controls insertion of I frames by the QSV encoder. turn ON this flag to allow changing of frame type from P and B to I.adaptive_bโ this flag controls changing of frame type from B to P.b_strategyโ this option controls usage of B frames as reference.extbrcโ extended bitrate control.look_ahead_depthโ depth of look ahead, in number of frames, available when theextbrcoption is enabled.low_delay_brcโ setting this flag turns on or off the LowDelayBRC feature in the qsv plugin, which provides more accurate bitrate control to minimize the variance of bitstream size frame by frame. value:-1-default,0-off,1-on.max_frame_sizeโ set the allowed max size in bytes for each frame. if the frame size exceeds the limitation, the encoder will adjust the QP value to control the frame size. invalid in CQP rate control mode โ ๏ธmax_frame_size_iโ maximum encoded frame size for I frames in bytes. if this value is set as larger than zero, then for I frames the value set bymax_frame_sizeis ignored.max_frame_size_pโ maximum encoded frame size for P frames in bytes. if this value is set as larger than zero, then for P frames the value set bymax_frame_sizeis ignored.
snow
Options
iterative_dia_sizeโdiasize for the iterative motion estimation. snow is such a vibe honestly โ๏ธ
VAAPI encoders
wrappers for hardware encoders accessible via VAAPI ๐ฅ
these encoders only accept input in VAAPI hardware surfaces. if you have input in software frames, use the hwupload filter to upload them to the GPU. don't fight it, just upload ๐ซถ
the following standard libavcodec options are used:
g/gop_sizebf/max_b_framesprofile
if not set, this will be determined automatically from the format of the input frames and the profiles supported by the driver. she'll figure it out herself ๐
levelb/bit_ratemaxrate/rc_max_ratebufsize/rc_buffer_sizerc_init_occupancy/rc_initial_buffer_occupancycompression_level
speed / quality tradeoff: higher values are faster / worse quality.
q/global_quality
size / quality tradeoff: higher values are smaller / worse quality.
qminqmaxi_qfactor/i_quant_factori_qoffset/i_quant_offsetb_qfactor/b_quant_factorb_qoffset/b_quant_offsetslices
all encoders support the following options:
low_powerโ some drivers/platforms offer a second encoder for some codecs intended to use less power than the default encoder; setting this option will attempt to use that encoder. note that it may support a reduced feature set, so some other options may not be available in this mode ๐idr_intervalโ set the number of normal intra frames between full-refresh (IDR) frames in open-GOP mode. the intra frames are still IRAPs, but will not include global headers and may have non-decodable leading pictures.b_depthโ set the B-frame reference depth. when set to one (the default), all B-frames will refer only to P- or I-frames. when set to greater values multiple layers of B-frames will be present, frames in each layer only referring to frames in higher layers. layers on layers, it's giving onion ๐งasync_depthโ maximum processing parallelism. increase this to improve single channel performance. this option doesn't work if the driver doesn't implement thevaSyncBufferfunction. please make sure there are enoughhw_framesallocated if a large number ofasync_depthis used. be responsible bestie โ ๏ธmax_frame_sizeโ set the allowed max size in bytes for each frame. if the frame size exceeds the limitation, the encoder will adjust the QP value to control the frame size. invalid in CQP rate control mode.rc_modeโ set the rate control mode to use. a given driver may only support a subset of modes.
possible modes:
autoโ choose the mode automatically based on driver support and the other options. this is the default.CQPโ constant-quality.CBRโ constant-bitrate.VBRโ variable-bitrate.ICQโ intelligent constant-quality.QVBRโ quality-defined variable-bitrate.AVBRโ average variable bitrate.
blbrcโ enable block level rate control, which assigns a different bitrate block by block. invalid for CQP mode.
each encoder also has its own specific options, naturally:
av1_vaapi
profile sets the value of seq_profile. tier sets the value of seq_tier. level sets the value of seq_level_idx.
tilesโ set the number of tiles to encode the input video with, as columns x rows. (default isauto, which means use minimal tile column/row number).tile_groupsโ set tile groups number. all the tiles will be distributed as evenly as possible to each tile group. (default is1).
h264_vaapi
profile sets the value of profile_idc and the constraint_set*_flags. level sets the value of level_idc.
coderโ set entropy encoder (default iscabac). possible values:accabacโ use CABAC.vlccavlcโ use CAVLC.
audโ include access unit delimiters in the stream (not included by default).seiโ set SEI message types to include. some combination of the following values:identifierโ include auser_data_unregisteredmessage containing information about the encoder.timingโ include picture timing parameters (buffering_periodandpic_timingmessages).
recovery_pointโ include recovery points where itโs appropriate (therecovery_pointmessages). ๐ซถ
๐ hevc_vaapi
profile and level set the values of general_profile_idc and general_level_idc respectively.
audโ include access unit delimiters in the stream (not included by default).tierโ setgeneral_tier_flag. This may affect the level chosen for the stream if it is not explicitly specified.seiโ set SEI message types to include. Some combination of the following values:hdrโ include HDR metadata if the input frames have it (mastering_display_colour_volumeandcontent_light_levelmessages).
tilesโ set the number of tiles to encode the input video with, ascolumns x rows. Larger numbers allow greater parallelism in both encoding and decoding, but may decrease coding efficiency.
๐ฆ mjpeg_vaapi
Only baseline DCT encoding is supported. The encoder always uses the standard quantisation and huffman tables โ global_quality scales the standard quantisation table (range 1-100).
For YUV, 4:2:0, 4:2:2 and 4:4:4 subsampling modes are supported. RGB is also supported, and will create an RGB JPEG.
jfifโ include JFIF header in each frame (not included by default).huffmanโ include standard huffman tables (on by default). Turning this off will save a few hundred bytes in each output frame, but may lose compatibility with some JPEG decoders which donโt fully handle MJPEG.
๐ธ mpeg2_vaapi
profile and level set the value of profile_and_level_indication.
๐ vp8_vaapi
B-frames are not supported.
global_quality sets the q_idx used for non-key frames (range 0-127).
loop_filter_levelโ manually set the loop filter parameters.loop_filter_sharpnessโ manually set the loop filter parameters.
โญ vp9_vaapi
global_quality sets the q_idx used for P-frames (range 0-255).
loop_filter_levelโ manually set the loop filter parameters.loop_filter_sharpnessโ manually set the loop filter parameters.
B-frames are supported, but the output stream is always in encode order rather than display order. If B-frames are enabled, it may be necessary to use the vp9_raw_reorder bitstream filter to modify the output stream to display frames in the correct order.
Only normal frames are produced โ the vp9_superframe bitstream filter may be required to produce a stream usable with all decoders.
๐ vbn
Vizrt Binary Image encoder.
This format is used by the broadcast vendor Vizrt for quick texture streaming. Advanced features of the format such as LZW compression of texture data or generation of mipmaps are not supported.
Options
formatstring โ sets the texture compression used by the VBN file. Can bedxt1,dxt5orraw. Default isdxt5.
๐ vc2
SMPTE VC-2 (previously BBC Dirac Pro). This codec was primarily aimed at professional broadcasting but since it supports yuv420, yuv422 and yuv444 at 8 (limited range or full range), 10 or 12 bits, this makes it suitable for other tasks which require low overhead and low compression (like screen recording).
Options
bโ sets target video bitrate. Usually thatโs around1:6of the uncompressed video bitrate (e.g. for1920x1080 50fps yuv422p10thatโs around400Mbps). Higher values (close to the uncompressed bitrate) turn on lossless compression mode.field_orderโ enables field coding when set (e.g. tottโ top field first) for interlaced inputs. Should increase compression with interlaced content as it splits the fields and encodes each separately.wavelet_depthโ sets the total amount of wavelet transforms to apply, between1and5(default). Lower values reduce compression and quality. Less capable decoders may not be able to handle values ofwavelet_depthover3.wavelet_typeโ sets the transform type. Currently only5_3(LeGall) and9_7(Deslauriers-Dubuc) are implemented, with9_7being the one with better compression and thus is the default.slice_widthโ sets the slice size for each slice. Larger values result in better compression. For compatibility with other more limited decoders useslice_widthof32.slice_heightโ sets the slice size for each slice. Larger values result in better compression. For compatibility with other more limited decoders useslice_heightof8.toleranceโ sets the undershoot tolerance of the rate control system in percent. This is to prevent an expensive search from being run.qmโ sets the quantization matrix preset to use by default or whenwavelet_depthis set to5.defaultโ uses the default quantization matrix from the specifications, extended with values for the fifth level. This provides a good balance between keeping detail and omitting artifacts.flatโ use a completely zeroed out quantization matrix. This increases PSNR but might reduce perception. Use in bogus benchmarks.colorโ reduces detail but attempts to preserve color at extremely low bitrates.
๐ SUBTITLES ENCODERS ๐
๐
dvbsub
This codec encodes the bitmap subtitle format that is used in DVB broadcasts and recordings. The bitmaps are typically embedded in a container such as MPEG-TS as a separate stream.
Options
min_bppinteger (2, 4, or 8) โ set a minimum bits-per-pixel value for the subtitle color lookup tables.
DVB supports 2, 4, and 8 bits-per-pixel color lookup tables. This option enables forcing a particular bits-per-pixel value regardless of the number of colors. Since not all players support or properly support 2 bits-per-pixel, this value defaults to 4.
๐ dvdsub
This codec encodes the bitmap subtitle format that is used in DVDs. Typically they are stored in VOBSUB file pairs (*.idx + *.sub), and they can also be used in Matroska files.
Options
paletteโ specify the global palette used by the bitmaps.
The format for this option is a string containing 16 24-bits hexadecimal numbers (without 0x prefix) separated by commas, for example "0d00ee, ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1, 7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b".
even_rows_fixโ when set to1, enable a work-around that makes the number of pixel rows even in all subtitles. This fixes a problem with some players that cut off the bottom row if the number is odd. The work-around just adds a fully transparent row if needed. The overhead is low, typically one byte per subtitle on average.
By default, this work-around is disabled.
๐ง lrc
This codec encodes the LRC lyrics format.
Options
precisionโ specify the precision of the fractional part of the timestamp. Time base is determined based on this value.
Defaults to 2 for centiseconds.
๐ BITSTREAM FILTERS ๐
When you configure your FFmpeg build, all the supported bitstream filters are enabled by default. You can list all available ones using the configure option "--list-bsfs".
You can disable all the bitstream filters using the configure option "--disable-bsfs", and selectively enable any bitstream filter using the option "--enable-bsf=BSF", or you can disable a particular bitstream filter using the option "--disable-bsf=BSF".
The option "-bsfs" of the ff* tools will display the list of all the supported bitstream filters included in your build.
The ff* tools have a -bsf option applied per stream, taking a comma-separated list of filters, whose parameters follow the filter name after a '='.
ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1:opt2=str2][,filter2] OUTPUT
Below is a description of the currently available bitstream filters, with their parameters, if any.
๐ aac_adtstoasc
Convert MPEG-2/4 AAC ADTS to an MPEG-4 Audio Specific Configuration bitstream.
This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4 ADTS header and removes the ADTS header.
This filter is required for example when copying an AAC stream from a raw ADTS AAC or an MPEG-TS container to MP4A-LATM, to an FLV file, or to MOV/MP4 files and related formats such as 3GP or M4A. Please note that it is auto-inserted for MP4A-LATM and MOV/MP4 and related formats.
๐ฅ av1_metadata
Modify metadata embedded in an AV1 stream.
tdโ insert or remove temporal delimiter OBUs in all temporal units of the stream.insertโ insert a TD at the beginning of every TU which does not already have one.removeโ remove the TD from the beginning of every TU which has one.
color_primariesโ set the color description fields in the stream (see AV1 section6.4.2).transfer_characteristicsโ set the color description fields in the stream (see AV1 section6.4.2).matrix_coefficientsโ set the color description fields in the stream (see AV1 section6.4.2).color_rangeโ set the color range in the stream (see AV1 section6.4.2; note that this cannot be set for streams using BT.709 primaries, sRGB transfer characteristic and identity (RGB) matrix coefficients).tvโ limited range.pcโ full range.
chroma_sample_positionโ set the chroma sample location in the stream (see AV1 section6.4.2). This can only be set for4:2:0streams.verticalโ left position (matching the default in MPEG-2 and H.264).colocatedโ top-left position.
tick_rateโ set the tick rate (time_scale / num_units_in_display_tick) in the timing info in the sequence header.num_ticks_per_pictureโ set the number of ticks in each picture, to indicate that the stream has a fixed framerate. Ignored iftick_rateis not also set.delete_paddingโ deletes Padding OBUs.
๐ซถ chomp
Remove zero padding at the end of a packet.
๐ dca_core
Extract the core from a DCA/DTS stream, dropping extensions such as DTS-HD.
๐ dovi_rpu
Manipulate Dolby Vision metadata in a HEVC/AV1 bitstream, optionally enabling metadata compression.
stripโ if enabled, strip all Dolby Vision metadata (configuration record + RPU data blocks) from the stream.compressionโ which compression level to enable.noneโ no metadata compression.limitedโ limited metadata compression scheme. Should be compatible with most devices. This is the default.extendedโ extended metadata compression. Devices are not required to support this. Note that this level currently behaves the same aslimitedin libavcodec.
โจ dump_extra
Add extradata to the beginning of the filtered packets except when said packets already exactly begin with the extradata that is intended to be added.
freqโ okay so this is the lil extra arg that tells the filter which packets get the extradata glow-up. It takes these values:k,keyframeโ adds extradata to all key packets ๐e,allโ adds extradata to literally every packet, no cap
If you don't specify it, it just assumes k. Default behavior, we love her.
So like, for example, this ffmpeg command forces a global header (which, yeah, disables individual packet headers) in the H.264 packets that the libx264 encoder makes, but then corrects them by adding the header stored in extradata to the key packets:
ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
๐ฉน dv_error_marker
Blocks in DV that are marked as damaged get swapped out for blocks of whatever color you pick. It's giving "cover it up with a cute sticker" energy but for corrupted video data.
colorโ the color used to replace the damaged blocks ๐staโ a 16 bit mask that says which of the 16 possible error status values get replaced by colored blocks.0xFFFEis the default, and it replaces all the non-0 error status values.okโ no error, no concealment โจerrโ error, no concealment ๐ญresโ reservednotokโ error or concealmentnotresโ not reservedAa,Ba,Ca,Ab,Bb,Cb,A,B,C,a,b,erri,erruโ the specific error status code
see page 44-46 or section 5.5 of <http://web.archive.org/web/20060927044735/http://www.smpte.org/smpte_store/standards/pdf/s314m.pdf> โ yes bestie, it's a real link, go read the spec, I believe in you ๐ซถ
๐งฒ eac3_core
Extracts the core out of an E-AC-3 stream, dropping the extra channels. Basically stripping it down to the basics, minimalism era.
๐ค eia608_to_smpte436m
Converts from a EIA_608 stream to a SMPTE_436M_ANC data stream โ and the way it does it is wrapping the closed captions in CTA-708 CDP VANC packets. Iconic little pipeline.
line_numberโ picks which line number the generated VANC packets go on. You generally want either line 9 (the default) or 11.wrapping_typeโ picks the SMPTE 436M wrapping type, defaults tovanc_frame. It accepts:vanc_frameโ VANC frame (interlaced or segmented progressive frame)vanc_field_1vanc_field_2vanc_progressive_frame
sample_codingโ picks the SMPTE 436M sample coding, defaults to8bit_luma. It accepts:8bit_lumaโ 8-bit component luma samples8bit_color_diffโ 8-bit component color difference samples8bit_luma_and_color_diffโ 8-bit component luma and color difference samples10bit_lumaโ 10-bit component luma samples10bit_color_diffโ 10-bit component color difference samples10bit_luma_and_color_diffโ 10-bit component luma and color difference samples8bit_luma_parity_errorโ 8-bit component luma samples with parity error8bit_color_diff_parity_errorโ 8-bit component color difference samples with parity error8bit_luma_and_color_diff_parity_errorโ 8-bit component luma and color difference samples with parity error
initial_cdp_sequence_cntrโ the initial value of the CDP's 16-bit unsigned integercdp_hdr_sequence_cntrandcdp_ftr_sequence_cntrfields. Defaults to0.cdp_frame_rateโ sets the CDP'scdp_frame_ratefield. And like, heads up: this doesn't actually change the timing of the data stream, it just changes the values inserted in that field in the generated CDP packets. Defaults to30000/1001.
๐ค extract_extradata
Extracts the in-band extradata. Let me explain, because this one's actually kind of cool:
Certain codecs let the long-term headers (think MPEG-2 sequence headers, or H.264/HEVC (VPS/)SPS/PPS) be transmitted either "in-band" (like, as a part of the bitstream that contains the coded frames) or "out of band" (like, on the container level). That second form? FFmpeg calls it "extradata" ๐
This bitstream filter detects the in-band headers and makes them available as extradata. Free the headers, honestly.
removeโ when this option is on, the long-term headers get removed from the bitstream after extraction. Gone, deleted, no notes.
๐ฆ filter_units
Removes units whose types are in โ or not in โ a given set, straight outta the stream.
pass_typesโ a list of unit types (or ranges of unit types) to pass through while removing all the others. You write it as a'|'-separated list of unit type values, or ranges of values with-.remove_typesโ same exact thing as pass_types, except the units in the given set get removed and everything else passes through. Inverse queen ๐
The types used by pass_types and remove_types correspond to NAL unit types (nal_unit_type) in H.264, HEVC and H.266 (see Table 7-1 in the H.264 and HEVC specifications or Table 5 in the H.266 specification), to marker values for JPEG (without 0xFF prefix) and to start codes without start code prefix (i.e. the byte following the 0x000001) for MPEG-2. For VP8 and VP9, every unit has type zero.
Extradata is unchanged by this transformation, but bestie, note this: if the stream contains inline parameter sets then the output may be unusable if they're removed. Like, actually unusable. Don't do that and then come crying to me ๐ญ
For example, to remove all non-VCL NAL units from an H.264 stream:
ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=pass_types=1-5' OUTPUT
To remove all AUDs, SEI and filler from an H.265 stream:
ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=35|38-40' OUTPUT
To remove all user data from a MPEG-2 stream, including Closed Captions:
ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=178' OUTPUT
To remove all SEI from a H264 stream, including Closed Captions:
ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=6' OUTPUT
To remove all prefix and suffix SEI from a HEVC stream, including Closed Captions and dynamic HDR:
ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=39|40' OUTPUT
๐จ hapqa_extract
Extracts the Rgb or Alpha part of an HAPQA file โ without recompression, because we're not out here degrading quality โ so you can make an HAPQ or an HAPAlphaOnly file. Crafty.
textureโ specifies which texture to keep.coloralpha
Convert HAPQA to HAPQ:
ffmpeg -i hapqa_inputfile.mov -c copy -bsf:v hapqa_extract=texture=color -tag:v HapY -metadata:s:v:0 encoder="HAPQ" hapq_file.mov
Convert HAPQA to HAPAlphaOnly:
ffmpeg -i hapqa_inputfile.mov -c copy -bsf:v hapqa_extract=texture=alpha -tag:v HapA -metadata:s:v:0 encoder="HAPAlpha Only" hapalphaonly_file.mov
๐ง h264_metadata
Modifies metadata that's embedded in an H.264 stream. She's a little surgeon, fr.
audโ inserts or removes AUD NAL units in all access units of the stream. Options:passinsertremove
Default is pass.
sample_aspect_ratioโ sets the sample aspect ratio of the stream in the VUI parameters. See H.264 table E-1.overscan_appropriate_flagโ sets whether the stream is suitable for display using overscan or not (see H.264 section E.2.1).video_format,video_full_range_flagโ sets the video format in the stream (see H.264 section E.2.1 and table E-2).colour_primaries,transfer_characteristics,matrix_coefficientsโ sets the colour description in the stream (see H.264 section E.2.1 and tables E-3, E-4 and E-5).chroma_sample_loc_typeโ sets the chroma sample location in the stream (see H.264 section E.2.1 and figure E-1).tick_rateโ sets the tick rate (time_scale / num_units_in_tick) in the VUI parameters. This is the smallest time unit representable in the stream, and in many cases it represents the field rate of the stream (double the frame rate). Math! โจfixed_frame_rate_flagโ sets whether the stream has a fixed framerate โ typically this indicates that the framerate is exactly half the tick rate, but the exact meaning depends on interlacing and the picture structure (see H.264 section E.2.1 and table E-6).zero_new_constraint_set_flagsโ zeroesconstraint_set4_flagandconstraint_set5_flagin the SPS. These bits were reserved in a previous version of the H.264 spec, and thus some hardware decoders require these to be zero. And good news: the result of zeroing this is still a valid bitstream ๐crop_left,crop_right,crop_top,crop_bottomโ sets the frame cropping offsets in the SPS. These values will replace the current ones if the stream is already cropped.
These fields are set in pixels. Note that some sizes may not be representable if the chroma is subsampled or the stream is interlaced (see H.264 section 7.4.2.1.1). So like, don't come for me if your weird number doesn't fit ๐
sei_user_dataโ inserts a string as SEI unregistered user data. The argument must be of the form UUID+string, where the UUID is as hex digits possibly separated by hyphens, and the string can be anything.
For example, 086f3693-b7b3-4f2c-9653-21492feee5b8+hello will insert the string ``hello'' associated with the given UUID. Cute little hidden message, iykyk.
delete_fillerโ deletes both filler NAL units and filler SEI messages. Bye, filler, you were never that important.display_orientationโ inserts, extracts or removes Display orientation SEI messages. See H.264 section D.1.27 and D.2.27 for syntax and semantics. Options:passinsertremoveextract
Default is pass.
Insert mode works in conjunction with rotate and flip options. Any pre-existing Display orientation messages will be removed in insert or remove mode. Extract mode attaches the display matrix to the packet as side data.
rotateโ sets rotation in display orientation SEI (anticlockwise angle in degrees). Range is-360to+360. Default isNaN. Spin her around ๐ซflipโ sets flip in display orientation SEI. Options:horizontalvertical
Default is unset.
levelโ sets the level in the SPS. Refer to H.264 section A.3 and tables A-1 to A-5.
The argument must be the name of a level (for example, 4.2), a level_idc value (for example, 42), or the special name auto indicating that the filter should attempt to guess the level from the input stream properties. Let her guess, she's smart.
๐ฌ h264_mp4toannexb
Converts an H.264 bitstream from length prefixed mode to start code prefixed mode (as defined in the Annex B of the ITU-T H.264 specification).
This is required by some streaming formats, typically the MPEG-2 transport stream format (muxer mpegts). So if you're going to mpegts, you literally need this, no cap.
For example, to remux an MP4 file containing an H.264 stream to mpegts format with ffmpeg, you can use the command:
ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
Please note that this filter is auto-inserted for MPEG-TS (muxermpegts) and raw H.264 (muxerh264) output formats. Like, it just does it for you. You don't have to ask ๐
๐ h264_redundant_pps
This applies a specific fixup to some Blu-ray BDMV H264 streams that contain redundant PPSs. The PPSs modify irrelevant parameters of the stream, confusing other transformations which require the correct extradata. So she's basically the friend who fixes your outfit before you go out โ the PPSs were messing up the vibe for everyone else ๐ซถ
okay so the encoder on those impacted streams? it keeps adding extra PPSs all the way through the stream, and it also switches up the initial QP and whether weighted prediction was on ๐ญ. thatโs a whole mess when you copy the stream into a global header container, because the starting PPS is not it for the rest of the stream. like, one side effect? seeking will return garbled output until a new PPS shows up. not cute.
This BSF removes those extra PPSs and rewrites the slice headers so the stream uses a single leading PPS in the global header, which resolves the issue. slay ๐ .
hevc_metadata
Modify metadata embedded in an HEVC stream โจ.
audโ Insert or remove AUD NAL units in all access units of the stream.insertremove
sample_aspect_ratioโ Set the sample aspect ratio in the stream in the VUI parameters.video_format,video_full_range_flagโ Set the video format in the stream (see H.265 section E.3.1 and table E.2).colour_primaries,transfer_characteristics,matrix_coefficientsโ Set the colour description in the stream (see H.265 section E.3.1 and tables E.3, E.4 and E.5).chroma_sample_loc_typeโ Set the chroma sample location in the stream (see H.265 section E.3.1 and figure E.1).tick_rateโ Set the tick rate in the VPS and VUI parameters (time_scale / num_units_in_tick). Combined withnum_ticks_poc_diff_one, this can set a constant framerate in the stream. Note that it is likely to be overridden by container parameters when the stream is in a container.num_ticks_poc_diff_oneโ Setpoc_proportional_to_timing_flagin VPS and VUI and use this value to setnum_ticks_poc_diff_one_minus1(see H.265 sections 7.4.3.1 and E.3.1). Ignored iftick_rateis not also set.crop_left,crop_right,crop_top,crop_bottomโ Set the conformance window cropping offsets in the SPS. These values will replace the current ones if the stream is already cropped. These fields are set in pixels. Note that some sizes may not be representable if the chroma is subsampled (H.265 section 7.4.3.2.1).width,heightโ Set width and height after crop.levelโ Set the level in the VPS and SPS. See H.265 section A.4 and tables A.6 and A.7. The argument must be the name of a level (for example,5.1), ageneral_level_idcvalue (for example,153for level 5.1), or the special nameautoindicating that the filter should attempt to guess the level from the input stream properties.
hevc_mp4toannexb
Convert an HEVC/H.265 bitstream from length prefixed mode to start code prefixed mode (as defined in the Annex B of the ITU-T H.265 specification).
This is required by some streaming formats, typically the MPEG-2 transport stream format (muxer mpegts).
For example to remux an MP4 file containing an HEVC stream to mpegts format with ffmpeg, you can use the command:
ffmpeg -i INPUT.mp4 -codec copy -bsf:v hevc_mp4toannexb OUTPUT.ts
Please note that this filter is auto-inserted for MPEG-TS (muxer mpegts) and raw HEVC/H.265 (muxer h265 or hevc) output formats.
imxdump
Modifies the bitstream to fit in MOV and to be usable by the Final Cut Pro decoder. This filter only applies to the mpeg2video codec, and is likely not needed for Final Cut Pro 7 and newer with the appropriate -tag:v.
For example, to remux 30 MB/sec NTSC IMX to MOV:
ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov
mjpeg2jpeg
Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
MJPEG is a video codec wherein each video frame is essentially a JPEG image. The individual frames can be extracted without loss, e.g. by
ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
Unfortunately, these chunks are incomplete JPEG images, because they lack the DHT segment required for decoding. Quoting from http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml:
Avery Lee, writing in the rec.video.desktop newsgroup in 2001, commented that "MJPEG, or at least the MJPEG in AVIs having the MJPG fourcc, is restricted JPEG with a fixed -- and omitted -- Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2, and it must use basic Huffman encoding, not arithmetic or progressive. . . . You can indeed extract the MJPEG frames and decode them with a regular JPEG decoder, but you have to prepend the DHT segment to them, or else the decoder won't have any idea how to decompress the data. The exact table necessary is given in the OpenDML spec."
This bitstream filter patches the header of frames extracted from an MJPEG stream (carrying the AVI1 header ID and lacking a DHT segment) to produce fully qualified JPEG images.
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
exiftran -i -9 frame*.jpg
ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
mjpegadump
Add an MJPEG A header to the bitstream, to enable decoding by Quicktime.
mov2textsub
Extract a representable text file from MOV subtitles, stripping the metadata header from each subtitle packet.
See also the text2movsub filter.
mpeg2_metadata
Modify metadata embedded in an MPEG-2 stream โจ.
display_aspect_ratioโ Set the display aspect ratio in the stream. The following fixed values are supported:4/316/9221/100
Any other value will result in square pixels being signalled instead (see H.262 section 6.3.3 and table 6-3).
frame_rateโ Set the frame rate in the stream. This is constructed from a table of known values combined with a small multiplier and divisor - if the supplied value is not exactly representable, the nearest representable value will be used instead (see H.262 section 6.3.3 and table 6-4).video_formatโ Set the video format in the stream (see H.262 section 6.3.6 and table 6-6).colour_primaries,transfer_characteristics,matrix_coefficientsโ Set the colour description in the stream (see H.262 section 6.3.6 and tables 6-7, 6-8 and 6-9).
mpeg4_unpack_bframes
Unpack DivX-style packed B-frames.
DivX-style packed B-frames are not valid MPEG-4 and were only a workaround for the broken Video for Windows subsystem. They use more space, can cause minor AV sync issues, require more CPU power to decode (unless the player has some decoded picture queue to compensate the 2,0,2,0 frame per packet style) and cause trouble if copied into a standard container like MP4 or mpeg-ps/ts, because MPEG-4 decoders may not be able to decode them, since they are not valid MPEG-4.
For example to fix an AVI file containing an MPEG-4 stream with DivX-style packed B-frames using ffmpeg, you can use the command:
ffmpeg -i INPUT.avi -codec copy -bsf:v mpeg4_unpack_bframes OUTPUT.avi
noise
Damages the contents of packets or simply drops them without damaging the container. Can be used for fuzzing or testing error resilience/concealment.
Parameters:
amountโ Accepts an expression whose evaluation per-packet determines how often bytes in that packet will be modified. A value below 0 will result in a variable frequency. Default is 0 which results in no modification. However, if neitheramountnordropis specified,amountwill be set to -1. See below for accepted variables.dropโ Accepts an expression evaluated per-packet whose value determines whether that packet is dropped. Evaluation to a positive value results in the packet being dropped. Evaluation to a negative value results in a variable chance of it being dropped, roughly inverse in proportion to the magnitude of the value. Default is 0 which results in no drops. See below for accepted variables.dropamountโ Accepts a non-negative integer, which assigns a variable chance of it being dropped, roughly inverse in proportion to the value. Default is 0 which results in no drops. This option is kept for backwards compatibility and is equivalent to settingdropto a negative value with the same magnitude i.e.dropamount=4is the same asdrop=-4. Ignored ifdropis also specified.
Both amount and drop accept expressions containing the following variables:
nโ The index of the packet, starting from zero.tbโ The timebase for packet timestamps.ptsโ Packet presentation timestamp.dtsโ Packet decoding timestamp.noptsโ Constant representingAV_NOPTS_VALUE.startptsโ First non-AV_NOPTS_VALUEPTS seen in the stream.startdtsโ First non-AV_NOPTS_VALUEDTS seen in the stream.duration,dโ Packet duration, in timebase units.posโ Packet position in input; may be-1when unknown or not set.sizeโ Packet size, in bytes.keyโ Whether packet is marked as a keyframe.stateโ A pseudo random integer, primarily derived from the content of packet payload.
Examples
Apply modification to every byte but don't drop any packets.
ffmpeg -i INPUT -c copy -bsf noise=1 output.mkv
Drop every video packet not marked as a keyframe after timestamp 30s but do not modify any of the remaining packets.
ffmpeg -i INPUT -c copy -bsf:v noise=drop='gt(pts*tb\,30)*not(key)' output.mkv
Drop one second of audio every 10 seconds and add some random noise to the rest.
ffmpeg -i INPUT -c copy -bsf:a noise=amount=-1:drop='between(mod(pts*tb\,10)\,9\,10)' output.mkv
null
This bitstream filter passes the packets through unchanged. iconic, no notes ๐ .
pcm_rechunk
Repacketize PCM audio to a fixed number of samples per packet or a fixed packet rate per second. This is similar to the asetnsamples audio filter but works on audio packets instead of audio frames.
nb_out_samples,nโ Set the number of samples per each output audio packet. The number is intended as the number of samples per each channel. Default value is1024.pad,pโ If set to1, the filter will pad the last audio packet with silence, so that it will contain the same number of samples (or roughly the same number of samples, seeframe_rate) as the previous ones. Default value is1.frame_rate,rโ This option makes the filter output a fixed number of packets per second instead of a fixed number of samples per packet. If the audio sample rate is not divisible by the frame rate then the number of samples will not be constant but will vary slightly so that each packet will start as close to the frame boundary as possible. Using this option has precedence overnb_out_samples.
You can generate the well known 1602-1601-1602-1601-1602 pattern of 48kHz audio for NTSC frame rate using the frame_rate option ๐.
ffmpeg -f lavfi -i sine=r=48000:d=1 -c pcm_s16le -bsf pcm_rechunk=r=30000/1001 -f framecrc -
pgs_frame_merge ๐
Bestie, this one merges a sequence of PGS Subtitle segments that ends with an โend of display setโ segment into a single packet. Itโs literally required by some containers that support PGS subtitles (muxer matroska). No cap. โจ
prores_metadata ๐ฆ
Okay so this filter modifies color property metadata embedded in a prores stream. Obsessed.
color_primariesโ set the color primaries. Available values are:autoโ keep the same color primaries property (default).unknownbt709bt470bgโ BT601 625smpte170mโ BT601 525bt2020smpte431โ DCI P3smpte432โ P3 D65
transfer_characteristicsโ set the color transfer. Available values are:autoโ keep the same transfer characteristics property (default).unknownbt709โ BT 601, BT 709, BT 2020smpte2084โ SMPTE ST 2084arib-std-b67โ ARIB STD-B67
matrix_coefficientsโ set the matrix coefficient. Available values are:autoโ keep the same colorspace property (default).unknownbt709smpte170mโ BT 601bt2020nc
Set Rec709 colorspace for each frame of the file ๐
ffmpeg -i INPUT -c copy -bsf:v prores_metadata=color_primaries=bt709:color_trc=bt709:colorspace=bt709 output.mov
Set Hybrid Log-Gamma parameters for each frame of the file ๐
ffmpeg -i INPUT -c copy -bsf:v prores_metadata=color_primaries=bt2020:color_trc=arib-std-b67:colorspace=bt2020nc output.mov
remove_extra ๐ง
Remove extradata from packets. Sheโs doing the most but in a minimal way.
It accepts the following parameter:
freqโ set which frame types to remove extradata from.kโ remove extradata from non-keyframes only.keyframeโ remove extradata from keyframes only.e,allโ remove extradata from all frames.
setts ๐
Set PTS and DTS in packets. Main character energy fr fr.
It accepts the following parameters:
ts,pts,dtsโ set expressions for PTS, DTS or both.durationโ set expression for duration.time_baseโ set output time base.prescaleโ set whether to convert time fields to user-set output time base before evaluation of expressions. Defaults to0.
The expressions are evaluated through the eval API and can contain the following constants:
Nโ the count of the input packet. Starting from0.TSโ the demux timestamp in input in case oftsordtsoption or presentation timestamp in case ofptsoption.POSโ the original position in the file of the packet, or undefined if undefined for the current packet.DTSโ the demux timestamp in input.PTSโ the presentation timestamp in input.DURATIONโ the duration in input.STARTDTSโ the DTS of the first packet.STARTPTSโ the PTS of the first packet.PREV_INDTSโ the previous input DTS.PREV_INPTSโ the previous input PTS.PREV_INDURATIONโ the previous input duration.PREV_OUTDTSโ the previous output DTS.PREV_OUTPTSโ the previous output PTS.PREV_OUTDURATIONโ the previous output duration.NEXT_DTSโ the next input DTS.NEXT_PTSโ the next input PTS.NEXT_DURATIONโ the next input duration.TBโ the timebase in which time fields are denominated. The user-set output timebase if prescale is enabled, else the input timebase.TB_OUTโ the output timebase.SRโ the sample rate of stream packet belongs.NOPTSโ theAV_NOPTS_VALUEconstant.
For example, to set PTS equal to DTS (not recommended if B-frames are involved):
ffmpeg -i INPUT -c:a copy -bsf:a setts=pts=DTS out.mkv
showinfo ๐
Log basic packet information. Mainly useful for testing, debugging, and development. Like a little vibe check for your packets, iykyk.
smpte436m_to_eia608 ๐ธ
Convert from a SMPTE_436M_ANC data stream to a EIA_608 stream, extracting the closed captions from CTA-708 CDP VANC packets, and ignoring all other data. Sheโs selective, and honestly? Same.
text2movsub ๐
Convert text subtitles to MOV subtitles (as used by the mov_text codec) with metadata headers.
See also the mov2textsub filter.
trace_headers ๐ฅ
Log trace output containing all syntax elements in the coded stream headers (everything above the level of individual coded blocks). This can be useful for debugging low-level stream issues.
Supports AV1, H.264, H.265, (M)JPEG, MPEG-2 and VP9, but depending on the build only a subset of these may be available. So likeโฆ check your build bestie, no cap.
truehd_core ๐
Extract the core from a TrueHD stream, dropping ATMOS data. Sheโs stripping it down to the essentials, periodt.
vp9_metadata ๐ฆ
Modify metadata embedded in a VP9 stream. Little header glow-up.
color_spaceโ set the color space value in the frame header. Note that any frame set to RGB will be implicitly set to PC range and that RGB is incompatible with profiles 0 and 2.unknownbt601bt709smpte170smpte240bt2020rgb
color_rangeโ set the color range value in the frame header. Note that any value imposed by the color space will take precedence over this value.tvpc
vp9_superframe โญ
Merge VP9 invisible (alt-ref) frames back into VP9 superframes. This fixes merging of split/segmented VP9 streams where the alt-ref frame was split from its visible counterpart. Reunited and it feels so good ๐ญ
vp9_superframe_split โจ
Split VP9 superframes into single frames. Simple. Iconic. No notes.
vp9_raw_reorder ๐
Given a VP9 stream with correct timestamps but possibly out of order, insert additional show-existing-frame packets to correct the ordering. Sheโs putting the timeline back in line, bestie. ๐ซถ
โจ FORMAT OPTIONS โจ
Okay bestie, so the libavformat library ships some generic global options that you can set on all the muxers and demuxers. And on top of that? Each muxer or demuxer can have its own lil private options that are specific to that one component. iykyk ๐
You set these by passing -option value in the FFmpeg tools, or by setting the value explicitly in the AVFormatContext options, or via the libavutil/opt.h API if you're doing the programmatic thing.
Here's the full list, no skips, we're reading the whole menu ๐
avioflagsflags (input/output) โ Possible values:directโ Reduce buffering.
probesizeinteger (input) โ Sets the probing size in bytes, i.e. how much data gets analyzed to get stream information. A higher value lets it detect more info when that info is dispersed into the stream, but it'll increase latency. Must be an integer not lesser than32. Default is5000000.max_probe_packetsinteger (input) โ Sets the max number of buffered packets when probing a codec. Default is2500packets.packetsizeinteger (output) โ Sets the packet size.fflagsflags โ Sets format flags. Some of these are only implemented for a limited number of formats, so don't come for me if your format doesn't vibe with them.
Possible values for input files:
discardcorruptโ Discard corrupted packets.fastseekโ Enable fast, but inaccurate seeks for some formats.genptsโ Generate missing PTS if DTS is present.igndtsโ Ignore DTS if PTS is also set. In case the PTS is set, the DTS value is set to NOPTS. This is ignored when thenofillinflag is set.ignidxโ Ignore index.nobufferโ Reduce the latency introduced by buffering during initial input streams analysis.nofillinโ Do not fill in missing values in packet fields that can be exactly calculated.noparseโ Disable AVParsers, this needs+nofillintoo.sortdtsโ Try to interleave output packets by DTS. At present, available only for AVIs with an index.
Possible values for output files:
autobsfโ Automatically apply bitstream filters as required by the output format. Enabled by default.bitexactโ Only write platform-, build- and time-independent data. This ensures that file and data checksums are reproducible and match between platforms. Its primary use is for regression testing.flush_packetsโ Write out packets immediately.shortestโ Stop muxing at the end of the shortest stream. It may be needed to increasemax_interleave_deltato avoid flushing the longer streams before EOF.
seek2anyinteger (input) โ Allow seeking to non-keyframes on demuxer level when supported if set to1. Default is0.analyzedurationinteger (input) โ Specify how many microseconds are analyzed to probe the input. Higher value = more accurate info detected, but also more latency. Defaults to5,000,000microseconds = 5 seconds.cryptokeyhexadecimal string (input) โ Set the decryption key.indexmeminteger (input) โ Set max memory used for timestamp index (per stream).rtbufsizeinteger (input) โ Set max memory used for buffering real-time frames.fdebugflags (input/output) โ Print specific debug info. Possible values:ts
max_delayinteger (input/output) โ Set maximum muxing or demuxing delay in microseconds.fpsprobesizeinteger (input) โ Set number of frames used to probe fps.audio_preloadinteger (output) โ Set microseconds by which audio packets should be interleaved earlier.chunk_durationinteger (output) โ Set microseconds for each chunk.chunk_sizeinteger (output) โ Set size in bytes for each chunk.err_detect,f_err_detectflags (input) โ Set error detection flags. Heads up:f_err_detectis deprecated and should be used only via theffmpegtool. ๐
Possible values:
crccheckโ Verify embedded CRCs.bitstreamโ Detect bitstream specification deviations.bufferโ Detect improper bitstream length.explodeโ Abort decoding on minor error detection.carefulโ Consider things that violate the spec and have not been seen in the wild as errors.compliantโ Consider all spec non compliancies as errors.aggressiveโ Consider things that a sane encoder should not do as an error.
max_interleave_deltainteger (output) โ Set maximum buffering duration for interleaving. Expressed in microseconds, defaults to10000000(10 seconds).
Bestie, here's the lore: to make sure all the streams are interleaved correctly, libavformat waits until it has at least one packet for each stream before actually writing any packets to the output file. When some streams are "sparse" (i.e. there are large gaps between successive packets), this can result in excessive buffering. ๐ญ
This field specifies the maximum difference between the timestamps of the first and the last packet in the muxing queue โ above that, libavformat will output a packet regardless of whether it has queued a packet for all the streams.
If set to 0, libavformat will continue buffering packets until it has a packet for each stream, no matter the maximum timestamp difference between the buffered packets.
use_wallclock_as_timestampsinteger (input) โ Use wallclock as timestamps if set to1. Default is0.avoid_negative_tsinteger (output) โ Possible values:make_non_negativeโ Shift timestamps to make them non-negative. Also note that this affects only leading negative timestamps, and not non-monotonic negative timestamps.make_zeroโ Shift timestamps so that the first timestamp is0.auto(default) โ Enables shifting when required by the target format.disabledโ Disables shifting of timestamp.
When shifting is enabled, all output timestamps get shifted by the same amount. Audio, video, and subtitles desynching and relative timestamp differences are preserved compared to how they would have been without shifting. ๐ซถ
skip_initial_bytesinteger (input) โ Set number of bytes to skip before reading header and frames if set to1. Default is0.correct_ts_overflowinteger (input) โ Correct single timestamp overflows if set to1. Default is1.flush_packetsinteger (output) โ Flush the underlying I/O stream after each packet. Default is-1(auto), which means the underlying protocol decides;1enables it and has the effect of reducing latency;0disables it and may increase IO throughput in some cases.output_ts_offsetoffset (output) โ Set the output time offset.
offset must be a time duration specification โ see the Time duration section in the ffmpeg-utils(1) manual.
The offset is added by the muxer to the output timestamps.
Specifying a positive offset means the corresponding streams are delayed by the time duration specified in offset. Default value is 0 (meaning no offset is applied).
format_whitelistlist (input) โ,-separated list of allowed demuxers. By default all are allowed.dump_separatorstring (input) โ Separator used to separate the fields printed on the command line about the Stream parameters. For example, to separate the fields with newlines and indentation:
ffprobe -dump_separator "
" -i ~/videos/matrixbench_mpeg2.mpg
max_streamsinteger (input) โ Specifies the maximum number of streams. This can be used to reject files that would require too many resources due to a large number of streams. Iconic gatekeeping behavior honestly ๐skip_estimate_duration_from_ptsbool (input) โ Skip estimation of input duration if it requires an additional probing for PTS at end of file. At present, applicable for MPEG-PS and MPEG-TS.duration_probesizeinteger (input) โ Set probing size, in bytes, for input duration estimation when it actually requires an additional probing for PTS at end of file (at present: MPEG-PS and MPEG-TS). It's aimed at users interested in better durations probing for itself, or indirectly because of using the concat demuxer, for example.
The typical use case is an MPEG-TS CBR with a high bitrate, high video buffering and ending cleaning with similar PTS for video and audio: in such a scenario, the large physical gap between the last video packet and the last audio packet makes it necessary to read many bytes in order to get the video stream duration. Another use case is where the default probing behaviour only reaches a single video frame which is not the last one of the stream due to frame reordering, so the duration is not accurate.
Setting this option has a performance impact even for small files because the probing size is fixed. Default behaviour is a general purpose trade-off, largely adaptive, but the probing size will not be extended to get streams durations at all costs. Must be an integer not lesser than 1, or 0 for default behaviour.
strict,f_strictinteger (input/output) โ Specify how strictly to follow the standards.f_strictis deprecated and should be used only via theffmpegtool. ๐
Possible values:
veryโ strictly conform to an older more strict version of the spec or reference softwarestrictโ strictly conform to all the things in the spec no matter what consequencesnormalunofficialโ allow unofficial extensionsexperimentalโ allow non standardized experimental things, experimental (unfinished/work in progress/not well tested) decoders and encoders.
Note: experimental decoders can pose a security risk โ do not use this for decoding untrusted input. Fr fr, be careful out there ๐จ
๐ Format stream specifiers ๐
Format stream specifiers let you select one or more streams that match specific properties. So like, choose-your-own-adventure but for streams.
The exact semantics of stream specifiers is defined by the avformat_match_stream_specifier() function declared in the libavformat/avformat.h header and documented in the Stream specifiers section in the ffmpeg(1) manual. Go read that one if you want the full tea โ
๐ DEMUXERS ๐
Demuxers are configured elements in FFmpeg that can read the multimedia streams from a particular type of file. They're the ones doing the reading, the main character energy of the input side, periodt. โจ
Okay so boom โ demuxers are on by default when you configure your build. Like, all of them. Every. Single. One. ๐
You can peep the full roster with the configure option --list-demuxers.
Wanna yeet them all and start from scratch? That's --disable-demuxers, then cherry-pick exactly the one you want back in with --enable-demuxer=DEMUXER, or kick an individual one out with --disable-demuxer=DEMUXER. Choose your fighter ๐
The -demuxers option on the ff* tools shows you the list of enabled demuxers. And if you want the combined demuxers-and-muxers glow-up list, that's -formats.
Below is the tea on some of the demuxers that are currently available. ๐
aa
Audible Format 2, 3, and 4 demuxer. It's giving audiobook girlie.
This one demuxes Audible Format 2, 3, and 4 (.aa) files.
aac
Raw Audio Data Transport Stream AAC demuxer.
This demuxer is here to demux an ADTS input that's carrying a single AAC stream alongwith any ID3v1/2 or APE tags inside it. Little tags, big vibes. โจ
apng
Animated Portable Network Graphics demuxer.
Used to demux APNG files. All headers โ but the PNG signature โ up to (but not including) the first fcTL chunk get transmitted as extradata. After that, frames are split as being all the chunks between two fcTL ones, or between the last fcTL and IEND chunks. Weird little system but it ate. ๐ฆ
Options
-ignore_loopbool โ Ignores the loop variable in the file if it's set. Default is enabled.-max_fpsint โ Maximum framerate in frames per second. A default of0imposes no limit at all, go feral.-default_fpsint โ Default framerate in frames per second when none is specified in the file (0meaning as fast as possible). Default is15.
asf
Advanced Systems Format demuxer.
This bad boy demuxes ASF files and MMS network streams.
-no_resync_searchbool โ Do not try to resynchronize by looking for a certain optional start code.
concat
Virtual concatenation script demuxer. Lowkey the main character of this section ๐
This demuxer reads a list of files and other directives from a text file, then demuxes them one after the other, as if all their packets had been muxed together. Like a friendship bracelet where every string is a file. ๐ซถ
Timestamps in the files get adjusted so that the first file starts at 0 and each next file starts exactly where the previous one finishes. Heads up though: this is done globally and may cause gaps if all streams do not have exactly the same length.
All files must have the same streams โ same codecs, same time base, etc. No mixing and matching, bestie.
The duration of each file is used to adjust the timestamps of the next file. If that duration is incorrect โ because it was computed using the bit-rate, or because the file is truncated, for example โ it can cause artifacts. The duration directive exists so you can override the duration stored in each file. โจ
Syntax
The script is a text file in extended-ASCII, with one directive per line. Empty lines, leading spaces and lines starting with # are ignored. The following directive is recognized:
file pathโ Path to a file to read; special characters and spaces must be escaped with backslash or single quotes.
All subsequent file-related directives apply to that file.
ffconcat version 1.0โ Identify the script type and version.
To make FFmpeg recognize the format automatically, this directive must appear exactly as is (no extra space or byte-order-mark) on the very first line of the script.
duration durโ Duration of the file. This information can be specified from the file; specifying it here may be more efficient or help if the information from the file is not available or accurate.
If the duration is set for all files, then it is possible to seek in the whole concatenated video. ๐
inpoint timestampโ In point of the file. When the demuxer opens the file it instantly seeks to the specified timestamp. Seeking is done so that all streams can be presented successfully at In point.
This directive works best with intra frame codecs, because for non-intra frame ones you will usually get extra packets before the actual In point and the decoded content will most likely contain frames before In point too. ๐ญ
For each file, packets before the file In point will have timestamps less than the calculated start timestamp of the file (negative in case of the first file), and the duration of the files (if not specified by the duration directive) will be reduced based on their specified In point.
Because of potential packets before the specified In point, packet timestamps may overlap between two concatenated files.
outpoint timestampโ Out point of the file. When the demuxer reaches the specified decoding timestamp in any of the streams, it handles it as an end of file condition and skips the current and all the remaining packets from all streams.
Out point is exclusive, which means that the demuxer will not output packets with a decoding timestamp greater or equal to Out point.
This directive works best with intra frame codecs and formats where all streams are tightly interleaved. For non-intra frame codecs you will usually get additional packets with presentation timestamp after Out point therefore the decoded content will most likely contain frames after Out point too. If your streams are not tightly interleaved you may not get all the packets from all streams before Out point and you may only will be able to decode the earliest stream until Out point. ๐
The duration of the files (if not specified by the duration directive) will be reduced based on their specified Out point.
file_packet_metadata key=valueโ Metadata of the packets of the file. The specified metadata will be set for each file packet. You can specify this directive multiple times to add multiple metadata entries. This directive is deprecated, usefile_packet_metainstead. ๐file_packet_meta key valueโ Metadata of the packets of the file. The specified metadata will be set for each file packet. You can specify this directive multiple times to add multiple metadata entries. (Yes, this is the glow-up version.)option key valueโ Option to access, open and probe the file. Can be present multiple times.streamโ Introduce a stream in the virtual file. All subsequent stream-related directives apply to the last introduced stream. Some streams properties must be set in order to allow identifying the matching streams in the subfiles. If no streams are defined in the script, the streams from the first file are copied.exact_stream_id idโ Set the id of the stream. If this directive is given, the string with the corresponding id in the subfiles will be used. This is especially useful for MPEG-PS (VOB) files, where the order of the streams is not reliable. ๐ฅstream_meta key valueโ Metadata for the stream. Can be present multiple times.stream_codec valueโ Codec for the stream.stream_extradata hex_stringโ Extradata for the string, encoded in hexadecimal.chapter id start endโ Add a chapter. id is an unique identifier, possibly small and consecutive.
Options
This demuxer accepts the following option:
safeโ If set to1, reject unsafe file paths and directives. A file path is considered safe if it does not contain a protocol specification and is relative and all components only contain characters from the portable character set (letters, digits, period, underscore and hyphen) and have no period at the beginning of a component.
If set to 0, any file name is accepted. Live your truth, I guess ๐
The default is 1.
auto_convertโ If set to1, try to perform automatic conversions on packet data to make the streams concatenable. The default is1.
Currently, the only conversion is adding the h264_mp4toannexb bitstream filter to H.264 streams in MP4 format. This is necessary in particular if there are resolution changes.
segment_time_metadataโ If set to1, every packet will contain thelavf.concat.start_timeand thelavf.concat.durationpacket metadata values which are the start_time and the duration of the respective file segments in the concatenated output expressed in microseconds. The duration metadata is only set if it is known based on the concat file. The default is0.
Examples
- Use absolute filenames and include some comments:
# my first filename
file /mnt/share/file-1.wav
# my second filename including whitespace
file '/mnt/share/file 2.wav'
# my third filename including whitespace plus single quote
file '/mnt/share/file 3'\''.wav'
- Allow for input format auto-probing, use safe filenames and set the duration of the first file:
ffconcat version 1.0
file file-1.wav
duration 20.0
file subdir/file-2.wav
dash
Dynamic Adaptive Streaming over HTTP demuxer. Streaming queen behavior ๐
This demuxer presents all AVStreams found in the manifest. By setting the discard flags on AVStreams the caller can decide which streams to actually receive. Each stream mirrors the id and bandwidth properties from the <Representation> as metadata keys named id and variant_bitrate respectively.
Options
This demuxer accepts the following option:
cenc_decryption_keyโ Default 16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7).cenc_decryption_keysโ Dictionary of 16-byte key ID => 16-byte key, both in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7).
dvdvideo
DVD-Video demuxer, powered by libdvdnav and libdvdread. Retro tech but make it slay ๐ฟ
Can directly ingest DVD titles, specifically sequential PGCs, into a conversion pipeline. Menu assets, such as background video or audio, can also be demuxed given the menu's coordinates (at best effort).
Block devices (DVD drives), ISO files, and directory structures are accepted. Activate with -f dvdvideo in front of one of these inputs.
โ ๏ธ This demuxer does NOT have decryption code of any kind. You are on your own working with encrypted DVDs, and should not expect support on the matter. Fr fr, don't come for me.
Underlying playback is handled by libdvdnav, and structure parsing by libdvdread. FFmpeg must be built with GPL library support available as well as the configure switches --enable-libdvdnav and --enable-libdvdread. ๐
You're gonna need to hand it either the "title number" you want or the exact PGC/PG coordinates โ like, pick one, bestie. Lots of open-source DVD players and tools can help you dig that info up. If you don't specify anything, the demuxer just defaults to title 1, which honestly works for a ton of discs. But because this format is so flexible, please check manually โ there are lots of discs out there authored weirdly or with straight-up invalid headers. ๐
Oh, and if your input is a real physical DVD drive? Heads up: some drives will silently fail reading bad sectors off the disc and just hand back random bits instead, which is effectively corrupt data. This is especially prominent on aging or rotting discs. You'd need a second pass plus integrity checks to even detect the corruption. And ngl โ that is not an FFmpeg issue. ๐
๐ Background
DVD-Video is not a directly accessible, linear container format in the traditional sense. Nope! Instead it allows for complex and programmatic playback of carefully muxed MPEG-PS streams that are stored in headerless VOB files. To the end-user these streams are known simply as "titles", but the actual logical playback sequence is defined by one or more "PGCs", or Program Group Chains, within the title. The PGC is in turn comprised of multiple "PGs", or Programs, which are the actual video segments (and for a typical video feature, sequentially ordered). The PGC structure, along with stream layout and metadata, are stored in IFO files that need to be parsed. PGCs can be thought of as playlists, if that's easier โ like, that's the vibe. โจ
An actual DVD player relies on user GUI interaction via menus and an internal VM to drive the direction of demuxing. Generally the user would either navigate (via menus) or automatically be redirected to the PGC of their choice. During this process and the subsequent playback, the DVD player's internal VM also maintains a state and executes instructions that can create jumps to different sectors during playback. This is why libdvdnav is involved โ because a linear read of the MPEG-PS blobs on the disc (VOBs) is just not enough to produce the right sequence in many cases. ๐ฆ
There are many other DVD structures (a long subject, truly a rabbit hole) that will not be discussed here. NAV packets, in particular, are handled by this demuxer to build accurate timing but are not emitted as a stream. For a good high-level understanding, refer to:
https://code.videolan.org/videolan/libdvdnav/-/blob/master/doc/dvd_structures
๐ Options
This demuxer accepts the following options:
titleint โ the title number to play. Must be set ifpgcandpgare not set. Not applicable to menus. Default is0(auto), which currently only selects the first available title (title 1) and notifies the user about the implications.chapter_startint โ the chapter, or PTT (part-of-title), number to start at. Not applicable to menus. Default is1.chapter_endint โ the chapter, or PTT (part-of-title), number to end at. Not applicable to menus. Default is0, which is a special value that signals "end at the last possible chapter".angleint โ the video angle number, referring to what is essentially an additional video stream that is composed from alternate frames interleaved in the VOBs. Not applicable to menus. Default is1.regionint โ the region code to use for playback. Some discs may use this to default playback at a particular angle in different regions. This option will not affect the region code of a real DVD drive, if used as an input. Not applicable to menus. Default is0, "world".menubool โ demux menu assets instead of navigating a title. Requires exact coordinates of the menu (menu_lu,menu_vts,pgc,pg). Default isfalse.menu_luint โ the menu language to demux. In DVD, menus are grouped by language. Default is1, the first language unit.menu_vtsint โ the VTS where the menu lives, or0if it is a VMG menu (root-level). Default is1, menu of the first VTS.pgcint โ the entry PGC to start playback, in conjunction withpg. An alternative to settingtitle. Chapter markers are not supported at this time. Must be explicitly set for menus. Default is0, automatically resolve from value oftitle.pgint โ the entry PG to start playback, in conjunction withpgc. An alternative to settingtitle. Chapter markers are not supported at this time. Default is1, the first PG of the PGC.preindexbool โ enable this to have accurate chapter (PTT) markers and duration measurement, which requires a slow second pass read in order to index the chapter marker timestamps from NAV packets. This is non-ideal extra work for real optical drives. It is recommended and faster to use this option with a backup of the DVD structure stored on a hard drive. Not compatible withpgcandpg. Default is0, false.trimbool โ skip padding cells (i.e. cells shorter than 1 second) from the beginning. There exist many discs with filler segments at the beginning of the PGC, often with junk data intended for controlling a real DVD player's buffering speed and with no other material data value. Not applicable to menus. Default is1, true.
๐ Examples
- Open title 3 from a given DVD structure:
ffmpeg -f dvdvideo -title 3 -i <path to DVD> ...
- Open chapters 3-6 from title 1 from a given DVD structure:
ffmpeg -f dvdvideo -chapter_start 3 -chapter_end 6 -title 1 -i <path to DVD> ...
- Open only chapter 5 from title 1 from a given DVD structure:
ffmpeg -f dvdvideo -chapter_start 5 -chapter_end 5 -title 1 -i <path to DVD> ...
- Demux menu with language 1 from VTS 1, PGC 1, starting at PG 1:
ffmpeg -f dvdvideo -menu 1 -menu_lu 1 -menu_vts 1 -pgc 1 -pg 1 -i <path to DVD> ...
๐ฎ ea
Electronic Arts Multimedia format demuxer, bestie.
This format is used by various Electronic Arts games. gamer moment. ๐น๏ธ
Options
merge_alphabool โ normally the VP6 alpha channel (if it exists) is returned as a secondary video stream; by setting this option you can make the demuxer return a single video stream which contains the alpha channel in addition to the ordinary video. Two-in-one, iconic behavior tbh.
๐ฌ imf
Interoperable Master Format demuxer.
This demuxer presents audio and video streams found in an IMF Composition, as specified in https://doi.org/10.5594/SMPTE.ST2067-2.2020.
ffmpeg [-assetmaps <path of ASSETMAP1>,<path of ASSETMAP2>,...] -i <path of CPL> ...
If -assetmaps is not specified, the demuxer looks for a file called ASSETMAP.xml in the same directory as the CPL. It'll find it, don't worry. ๐
๐บ flv, live_flv, kux
Adobe Flash Video Format demuxer. Yes, FLV still exists, we're being thorough.
This demuxer is used to demux FLV files and RTMP network streams. In the case of live network streams, if you force the format, you may use live_flv instead of flv to survive timestamp discontinuities. KUX is an flv variant used on the Youku platform.
ffmpeg -f flv -i myfile.flv ...
ffmpeg -f live_flv -i rtmp://<any.server>/anything/key ....
-flv_metadatabool โ allocate the streams according to theonMetaDataarray content.-flv_ignore_prevtagbool โ ignore the size of previous tag value.-flv_full_metadatabool โ output all context of theonMetadata.
๐ง gif
Animated GIF demuxer. The format we all love to hate, but she's serving. ๐
It accepts the following options:
min_delayโ set the minimum valid delay between frames, in hundredths of seconds. Range is0to6000. Default value is2.max_gif_delayโ set the maximum valid delay between frames, in hundredths of seconds. Range is0to65535. Default value is65535(nearly eleven minutes), the maximum value allowed by the specification.default_delayโ set the default delay between frames, in hundredths of seconds. Range is0to6000. Default value is10.ignore_loopโ GIF files can contain information to loop a certain number of times (or infinitely). Ifignore_loopis set to1, then the loop setting from the input will be ignored and looping will not occur. If set to0, then looping will occur and will cycle the number of times according to the GIF. Default value is1.
For example, with the overlay filter, place an infinitely looping GIF over another video:
ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
Note that in the above example the shortest option for overlay filter is used to end the output video at the length of the shortest input file, which in this case is input.mp4 as the GIF in this example loops infinitely. Otherwise you'd be there forever, literally. ๐ญ
๐ hls
HLS demuxer. Apple HTTP Live Streaming demuxer, to be precise.
This demuxer presents all AVStreams from all variant streams. The id field is set to the bitrate variant index number. By setting the discard flags on AVStreams (by pressing a or v in ffplay), the caller can decide which variant streams to actually receive. The total bitrate of the variant that the stream belongs to is available in a metadata key named "variant_bitrate". cute, right? โจ
It accepts the following options:
live_start_indexโ segment index to start live streams at (negative values are from the end).prefer_x_startโ prefer to use#EXT-X-STARTif it's in playlist instead oflive_start_index.allowed_extensionsโ','separated list of file extensions that hls is allowed to access.extension_pickyโ this blocks disallowed extensions from probing. It also requires all available segments to have matching extensions to the format exceptmpegts, which is always allowed. It is recommended to set the whitelists correctly instead of depending on extensions. Enabled by default.max_reloadโ maximum number of times a insufficient list is attempted to be reloaded. Default value is1000.m3u8_hold_countersโ the maximum number of times to load m3u8 when it refreshes without new segments. Default value is1000.http_persistentโ use persistent HTTP connections. Applicable only for HTTP streams. Enabled by default.http_multipleโ use multiple HTTP connections for downloading HTTP segments. Enabled by default for HTTP/1.1 servers.http_seekableโ use HTTP partial requests for downloading HTTP segments.0= disable,1= enable,-1= auto, Default is auto.seg_format_optionsโ set options for the demuxer of media segments using a list ofkey=valuepairs separated by":".seg_max_retryโ maximum number of times to reload a segment on error, useful when segment skip on network error is not desired. Default value is0.
๐ image2
Image file demuxer.
Okay so this demuxer pulls frames from a whole list of image files that you describe with a pattern, and the syntax/meaning of that pattern is decided by the pattern_type option. ๐
The pattern can carry a suffix, and that suffix is what auto-decides the format of the images inside those files.
Heads up bestie: the size, the pixel format, and the format of every image must be identical across all the files in the sequence. No mixing, no cap.
It accepts the following options:
framerateโ sets the frame rate for the video stream. Defaults to25.loopโ if set to1, it loops over the input. Default value is0.pattern_typeโ picks the pattern type used to interpret the filename you handed over.
pattern_type accepts one of these values:
noneโ disables pattern matching entirely, so the video will only contain the one image you specified. Use this if you don't wanna build sequences out of multiple images and your filenames might have special pattern characters in them. ๐ซถsequenceโ selects a sequence pattern type, which is what you use to specify a sequence of files indexed by sequential numbers.
A sequence pattern may contain the string %d or %0Nd, which specifies the position of the characters representing a sequential number in each filename matched by the pattern. If the form %d0Nd is used, the string representing the number in each filename is 0-padded and N is the total number of 0-padded digits representing the number. The literal character % can be specified in the pattern with the string %%.
If the sequence pattern contains %d or %0Nd, the first filename of the file list specified by the pattern must contain a number inclusively contained between start_number and start_number+start_number_range-1, and all the following numbers must be sequential. (yes, that's a real requirement, no skipping numbers on me ๐ญ)
For example the pattern img-%03d.bmp will match a sequence of filenames of the form img-001.bmp, img-002.bmp, ..., img-010.bmp, etc.; the pattern i%%m%%g-%d.jpg will match a sequence of filenames of the form i%m%g-1.jpg, i%m%g-2.jpg, ..., i%m%g-10.jpg, etc.
Note that the pattern must not necessarily contain %d or %0Nd, for example to convert a single image file img.jpeg you can employ the command:
ffmpeg -i img.jpeg img.png
globโ selects a glob wildcard pattern type.
The pattern is interpreted like a glob() pattern. This is only selectable if libavformat was compiled with globbing support. (so if it's not working, that's a compile-time thing, not you being dumb ๐)
Default value is sequence.
pixel_formatโ sets the pixel format of the images to read. If you don't specify it, the pixel format gets guessed from the first image file in the sequence.start_numberโ sets the index of the file matched by the image file pattern that reading starts from. Default value is0.start_number_rangeโ sets the index interval range to check when hunting for the first image file in the sequence, starting fromstart_number. Default value is5.ts_from_fileโ if set to1, it sets the frame timestamp to the modification time of the image file. Note that monotonity of timestamps is not provided: images go in the same order as without this option. Default value is0. If set to2, it sets the frame timestamp to the modification time of the image file in nanosecond precision. โฑ๏ธvideo_sizeโ sets the video size of the images to read. If not specified, the video size gets guessed from the first image file in the sequence.export_path_metadataโ if set to1, it adds two extra fields to the metadata found in the input, which also makes them available to other filters (peep thedrawtextfilter for examples). Default value is0. The extra fields are:lavf.image2dec.source_pathโ corresponds to the full path to the input file being read.lavf.image2dec.source_basenameโ corresponds to the name of the file being read.
๐ซ Examples
- Use
ffmpegto create a video from the images in the file sequenceimg-001.jpeg,img-002.jpeg, ..., assuming an input frame rate of 10 frames per second:
ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
- Same as above, but start by reading from a file with index
100in the sequence:
ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
- Read images matching the
*.pngglob pattern, that is all the files terminating with the.pngsuffix:
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
๐ฎ libgme
The Game Music Emu library is a whole collection of video game music file emulators. Iconic honestly.
See <https://bitbucket.org/mpyne/game-music-emu/overview> for more information.
It accepts the following options:
track_indexโ sets the index of which track to demux. The demuxer can only export one track. Track indexes start at0. Default is to pick the first track. The number of tracks gets exported as thetracksmetadata entry.sample_rateโ sets the sampling rate of the exported track. Range is1000to999999. Default is44100.max_size(bytes) โ the demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size, which in turn acts as a ceiling for the size of files that can be read. Default is50 MiB.
๐๏ธ libmodplug
ModPlug based module demuxer.
See <https://github.com/Konstanty/libmodplug>
It will export one 2-channel 16-bit 44.1 kHz audio stream. Optionally, a pal8 16-color video stream can be exported with or without printed metadata. ๐
It accepts the following options:
noise_reductionโ applies a simple low-pass filter. Can be1(on) or0(off). Default is0.reverb_depthโ sets the amount of reverb. Range0-100. Default is0.reverb_delayโ sets the delay in ms, clamped to40-250ms. Default is0.bass_amountโ applies bass expansion a.k.a. XBass or megabass. Range is0(quiet) to100(loud). Default is0.bass_rangeโ sets the cutoff, i.e. the upper bound for bass frequencies. Range is10-100Hz. Default is0.surround_depthโ applies a Dolby Pro-Logic surround effect. Range is0(quiet) to100(heavy). Default is0.surround_delayโ sets the surround delay in ms, clamped to5-40ms. Default is0.max_sizeโ the demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size, which in turn acts as a ceiling for the size of files that can be read. Range is0to100 MiB.0removes the buffer size limit (not recommended ๐ซฃ). Default is5 MiB.video_stream_exprโ a string which is evaluated using the eval API to assign colors to the generated video stream. The variables you can use arex,y,w,h,t,speed,tempo,order,patternandrow.video_streamโ generates the video stream. Can be1(on) or0(off). Default is0.video_stream_wโ sets the video frame width in 'chars' where one char indicates 8 pixels. Range is20-512. Default is30.video_stream_hโ sets the video frame height in 'chars' where one char indicates 8 pixels. Range is20-512. Default is30.video_stream_ptxtโ prints metadata on the video stream. Includesspeed,tempo,order,pattern,rowandts(time in ms). Can be1(on) or0(off). Default is1.
๐ผ libopenmpt
libopenmpt based module demuxer.
See <https://lib.openmpt.org/libopenmpt/> for more information.
Some files have multiple subsongs (tracks), and that can be set with the subsong option.
It accepts the following options:
subsongโ sets the subsong index. This can be either'all','auto', or the index of the subsong. Subsong indexes start at0. The default is'auto'.
The default value is to let libopenmpt choose. (letting the library be the main character, we love to see it ๐)
layoutโ sets the channel layout. Valid values are 1, 2, and 4 channel layouts. The default value isSTEREO.sample_rateโ sets the sample rate forlibopenmptto output. Range is from1000toINT_MAX. The value default is48000.
๐บ mcc
Demuxer for MacCaption MCC files โ it supports MCC versions 1.0 and 2.0. MCC files store VANC data, which can include closed captions (EIA-608 and CEA-708), ancillary time code, pan-scan data, etc. By default, for backward compatibility, the MCC demuxer extracts just the EIA-608 and CEA-708 closed captions and returns an EIA_608 stream, ignoring all other VANC data. You can flip it to return all VANC data in a SMPTE_436M_ANC data stream by setting -eia608_extract 0. โจ
๐ซ Examples
- Convert a MCC file to Scenarist (SCC) format:
ffmpeg -i CC.mcc -c:s copy CC.scc
Note that the SCC format only supports EIA-608, so this will discard all other data such as CEA-708 extensions. (rip the extras ๐ญ)
- Merge a MCC file into a MXF file:
ffmpeg -i video_and_audio.mxf -eia608_extract 0 -i CC.mcc -c copy -map 0 -map 1 out.mxf
This retains all VANC data and inserts it into the output MXF file as a SMPTE_436M_ANC data stream. Slay.
๐ฌ mov/mp4/3gp
Demuxer for Quicktime File Format & ISO/IEC Base Media File Format (ISO/IEC 14496-12 or MPEG-4 Part 12, ISO/IEC 15444-12 or JPEG 2000 Part 12).
Registered extensions: mov, mp4, m4a, 3gp, 3g2, mj2, psp, m4b, ism, ismv, isma, f4v
โ๏ธ Options
This demuxer accepts the following options:
enable_drefsโ enables loading of external tracks, disabled by default. Enabling this can theoretically leak information in some use cases. โ ๏ธ (like, actually think about it first)use_absolute_pathโ allows loading of external tracks via absolute paths, disabled by default. Enabling this poses a security risk. It should only be enabled if the source is known to be non-malicious. ๐จseek_streams_individuallyโ when seeking, identify the closest point in each stream individually and demux packets in that stream from the identified point. This can lead to a different sequence of packets compared to demuxing linearly from the beginning. Default istrue.ignore_editlistโ ignore any edit list atoms. The demuxer, by default, modifies the stream index to reflect the timeline described by the edit list. Default isfalse.advanced_editlistโ modify the stream index to reflect the timeline described by the edit list.ignore_editlistmust be set tofalsefor this option to be effective. If bothignore_editlistand this option are set tofalse, then only the start of the stream index is modified to reflect initial dwell time or starting timestamp described by the edit list. Default istrue.
still in the MOV/MP4 demuxer options, bestie โ these are the deep-lore file internals ๐
ignore_chaptersโ donโt parse chapters. This includes GoPro'HiLight'tags/moments. Note that chapters are only parsed when the input is seekable. Default isfalse.use_mfra_forโ for seekable fragmented input, set the fragmentโs starting timestamp from the media fragment random access box, if present. The options are:autoโ auto-detect whether to setmfratimestamps as PTS or DTS (default)dtsโ setmfratimestamps as DTSptsโ setmfratimestamps as PTS0โ donโt use themfrabox to set timestamps
use_tfdtโ for fragmented input, set the fragmentโs starting timestamp tobaseMediaDecodeTimefrom thetfdtbox. Default is enabled, which will prefer to use thetfdtbox to set DTS. Disable to use theearliest_presentation_timefrom thesidxbox. In either case, the timestamp from themfrabox will be used if itโs available anduse_mfra_foris set toptsordts.export_allโ export unrecognized boxes within theudtabox as metadata entries. The first four characters of the box type are set as the key. Default isfalse.export_xmpโ export the entire contents of theXMP_box anduuidbox as a string with keyxmp. Note that ifexport_allis set and this option isnโt, the contents of theXMP_box are still exported but with keyXMP_. Default isfalse.activation_bytesโ the4-bytekey required to decrypt Audible AAX and AAX+ files. See the Audible AAX subsection below.audible_fixed_keyโ fixed key used for handling Audible AAX/AAX+ files. It has been pre-set so it should not be necessary to specify it.decryption_keyโ default16-bytekey, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7).decryption_keysโ dictionary of16-bytekey ID =>16-bytekey, both in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7).max_stts_deltaโ very high sample deltas written in atrakโssttsbox may occasionally be intended, but usually theyโre written in error or used to store a negative value for dts correction when treated as signed 32-bit integers. This option lets the user set an upper limit, beyond which the delta is clamped to1. Values greater than the limit, if negative when cast toint32, are used to adjust onward dts. Unit is the track time scale. Range is0toUINT_MAX. Default isUINT_MAX - 48000*10, which allows up to a 10 second dts correction for 48 kHz audio streams while accommodating 99.9% ofuint32range.interleaved_readโ interleave packets from multiple tracks at demuxer level. For badly interleaved files, this prevents playback issues caused by large gaps between packets in different tracks, as MOV/MP4 do not have packet placement requirements. However, this can cause excessive seeking on very badly interleaved files, due to seeking between tracks, so disabling it may prevent I/O issues, at the expense of playback.
๐ง Audible AAX ๐ง
Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret. iconic little secret key moment ๐
ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4
๐บ mpegts ๐บ
MPEG-2 transport stream demuxer. this one accepts the following options:
resync_sizeโ set size limit for looking up a new synchronization. Default value is65536.skip_unknown_pmtโ skip PMTs for programs not defined in the PAT. Default value is0.fix_teletext_ptsโ override teletext packet PTS and DTS values with the timestamps calculated from the PCR of the first program which the teletext stream is part of and is not discarded. Default value is1; set this option to0if you want your teletext packet PTS and DTS values untouched.ts_packetsizeโ output option carrying the raw packet size in bytes. Show the detected raw packet size, cannot be set by the user.scan_all_pmtsโ scan and combine all PMTs. The value is an integer with value from-1to1(-1means automatic setting,1means enabled,0means disabled). Default value is-1.merge_pmt_versionsโ reuse existing streams when a PMTโs version is updated and elementary streams move to different PIDs. Default value is0.max_packet_sizeโ set maximum size, in bytes, of packet emitted by the demuxer. Payloads above this size are split across multiple packets. Range is184toINT_MAX/2. Default is204800bytes.
๐ผ๏ธ mpjpeg ๐ผ๏ธ
MJPEG encapsulated in multi-part MIME demuxer. this demuxer lets you read MJPEG where each frame is represented as a part of multipart/x-mixed-replace stream.
strict_mime_boundaryโ the default implementation applies a relaxed standard to multi-part MIME boundary detection, to prevent regression with numerous existing endpoints not generating a proper MIME MJPEG stream. Turning this option on by setting it to1will result in a stricter check of the boundary value.
๐ฅ rawvideo ๐ฅ
Raw video demuxer. This demuxer allows one to read raw video data. Since there is no header specifying the assumed video parameters, the user must specify them in order to be able to decode the data correctly. no cap, you gotta tell it everything yourself ๐ญ
This demuxer accepts the following options:
framerateโ set input video frame rate. Default value is25.pixel_formatโ set the input video pixel format. Default value isyuv420p.strideโ set frame line size in bytes, only required if there is extra padding. For multiplane formats,strideis a list of line size for each plane.video_sizeโ set the input video size. This value must be specified explicitly.
For example, to read a rawvideo file input.raw with ffplay, assuming a pixel format of rgb24, a video size of 320x240, and a frame rate of 10 images per second, use the command:
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
Read a rawvideo with ffplay, assuming a pixel format of yuv420p, a video size of 1080x1920, 8 bytes of padding in each line of Y plane, and 4 bytes of padding with UV plane,
ffplay -f rawvideo -pixel_format yuv420p -video_size 1080x1920 -stride 1088,544,544 input.raw
๐ฌ rcwt ๐ฌ
RCWT (Raw Captions With Time) is a format native to ccextractor, a commonly used open source tool for processing 608/708 Closed Captions (CC) sources. For more information on the format, see . the manpage really leaves it at that, bestie ๐
This demuxer implements the specification as of March 2024, which has been stable and unchanged since April 2014.
๐ Examples ๐
- Render CC to ASS using the built-in decoder:
ffmpeg -i CC.rcwt.bin CC.ass
Note that if your output appears to be empty, you may have to manually set the decoderโs data_field option to pick the desired CC substream.
- Convert an RCWT backup to Scenarist (SCC) format:
ffmpeg -i CC.rcwt.bin -c:s copy CC.scc
Note that the SCC format does not support all of the possible CC extensions that can be stored in RCWT (such as EIA-708).
๐ต sbg ๐ต
SBaGen script demuxer. This demuxer reads the script language used by SBaGen (http://uazu.net/sbagen/) to generate binaural beats sessions. A SBG script looks like that:
-SE
a: 300-2.5/3 440+4.5/0
b: 300-2.5/0 440+4.5/3
off: -
NOW == a
+0:07:00 == b
+0:14:00 == a
+0:21:00 == b
+0:30:00 off
A SBG script can mix absolute and relative timestamps. If the script uses either only absolute timestamps (including the script start time) or only relative ones, then its layout is fixed, and the conversion is straightforward. On the other hand, if the script mixes both kinds of timestamps, then the NOW reference for relative timestamps will be taken from the current time of day at the time the script is read, and the script layout will be frozen according to that reference. That means that if the script is directly played, the actual times will match the absolute timestamps up to the sound controllerโs clock accuracy, but if the user somehow pauses the playback or seeks, all times will be shifted accordingly. clock accuracy tea, periodt โฐ
๐ฃ๏ธ tedcaptions ๐ฃ๏ธ
JSON captions used for http://www.ted.com/. TED does not provide links to the captions, but they can be guessed from the page. The file tools/bookmarklets.html from the FFmpeg source tree contains a bookmarklet to expose them. bookmarklet magic iykyk โจ
This demuxer accepts the following option:
start_timeโ set the start time of the TED talk, in milliseconds. The default is15000(15s). It is used to sync the captions with the downloadable videos, because they include a 15s intro.
Example: convert the captions to a format most players understand:
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
๐ง vapoursynth ๐ง
Vapoursynth wrapper. Due to security concerns, Vapoursynth scripts will not be autodetected, so the input format has to be forced. For ff* CLI tools, add -f vapoursynth before the input -i yourscript.vpy. security said no autodetect, bestie ๐
This demuxer accepts the following option:
max_script_sizeโ the demuxer buffers the entire script into memory. Adjust this value to set the maximum buffer size, which in turn acts as a ceiling for the size of scripts that can be read. Default is1 MiB.
๐ง w64 ๐ง
Sony Wave64 Audio demuxer.
This demuxer accepts the following option:
max_sizeโ see the same option for thewavdemuxer.
๐ wav ๐
RIFF Wave Audio demuxer.
This demuxer accepts the following option:
max_sizeโ specify the maximum packet size in bytes for the demuxed packets. By default this is set to0, which means that a sensible value is chosen based on the input format.
๐ MUXERS ๐
Muxers are configured elements in FFmpeg which allow writing multimedia streams to a particular type of file. the write-it-out girlies ๐
When you configure your FFmpeg build, all the supported muxers are enabled by default. You can list all available muxers using the configure option --list-muxers.
You can disable all the muxers with the configure option --disable-muxers and selectively enable / disable single muxers with the options --enable-muxer=MUXER / --disable-muxer=MUXER.
The option -muxers of the ff* tools will display the list of enabled muxers. Use -formats to view a combined list of enabled demuxers and muxers.
A description of some of the currently available muxers follows. and bestie, there are a lot of them ๐ญ
๐ฟ Raw muxers ๐ฟ
okay so this little corner is all about raw muxers. They take a single stream that matches the designated codec, and they do not store timestamps or metadata. The recognized extension is the same as the muxer name unless it says otherwise. โจ
It comprises the following muxers โ the media type and any extensions used to auto-select the muxer from the output extensions are shown too. ๐ซถ
ac3โ audio: Dolby Digital, also known as AC-3.adxโ audio: CRI Middleware ADX audio. ๐ This muxer writes out the total sample count near the start of the first packet when the output is seekable and the count can be stored in 32 bits.aptxโ audio: aptX (Audio Processing Technology for Bluetooth).aptx_hdโ audio (aptxdh): aptX HD (Audio Processing Technology for Bluetooth) audio.avs2โ video (avs,avs2): AVS2-P2 (Audio Video Standard - Second generation - Part 2) / IEEE 1857.4 video.avs3โ video (avs3): AVS3-P2 (Audio Video Standard - Third generation - Part 2) / IEEE 1857.10 video.cavsvideoโ video (cavs): Chinese AVS (Audio Video Standard - First generation).codec2rawโ audio: Codec 2 audio. โ ๏ธ No extension is registered, so the format name has to be supplied, e.g. with the ffmpeg CLI tool-f codec2raw.dataโ any: Generic data muxer. This muxer accepts a single stream with any codec of any type. The input stream has to be selected using the-mapoption with the ffmpeg CLI tool. โ ๏ธ No extension is registered, so the format name has to be supplied, e.g. with the ffmpeg CLI tool-f data.dfpwmโ audio (dfpwm): Raw DFPWM1a (Dynamic Filter Pulse With Modulation) audio muxer.diracโ video (drc,vc2): BBC Dirac video. The Dirac Pro codec is a subset and is standardized as SMPTE VC-2.dnxhdโ video (dnxhd,dnxhr): Avid DNxHD video. It is standardized as SMPTE VC-3. Accepts DNxHR streams.dtsโ audio: DTS Coherent Acoustics (DCA) audio.eac3โ audio: Dolby Digital Plus, also known as Enhanced AC-3.evcโ video (evc): MPEG-5 Essential Video Coding (EVC) / EVC / MPEG-5 Part 1 EVC video.g722โ audio: ITU-T G.722 audio.g723_1โ audio (tco,rco): ITU-T G.723.1 audio.g726โ audio: ITU-T G.726 big-endian ("left-justified") audio. โ ๏ธ No extension is registered, so the format name has to be supplied, e.g. with the ffmpeg CLI tool-f g726.g726leโ audio: ITU-T G.726 little-endian ("right-justified") audio. โ ๏ธ No extension is registered, so the format name has to be supplied, e.g. with the ffmpeg CLI tool-f g726le.gsmโ audio: Global System for Mobile Communications audio.h261โ video: ITU-T H.261 video.h263โ video: ITU-T H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2 video.h264โ video (h264,264): ITU-T H.264 / MPEG-4 Part 10 AVC video. Bitstream shall be converted to Annex B syntax if it's in length-prefixed mode.hevcโ video (hevc,h265,265): ITU-T H.265 / MPEG-H Part 2 HEVC video. Bitstream shall be converted to Annex B syntax if it's in length-prefixed mode.m4vโ video: MPEG-4 Part 2 video.mjpegโ video (mjpg,mjpeg): Motion JPEG video.mlpโ audio: Meridian Lossless Packing, also known as Packed PCM.mp2โ audio (mp2,m2a,mpa): MPEG-1 Audio Layer II audio.mpeg1videoโ video (mpg,mpeg,m1v): MPEG-1 Part 2 video.mpeg2videoโ video (m2v): ITU-T H.262 / MPEG-2 Part 2 video.obuโ video: AV1 low overhead Open Bitstream Units muxer. Temporal delimiter OBUs will be inserted in all temporal units of the stream.rawvideoโ video (yuv,rgb): Raw uncompressed video.sbcโ audio (sbc,msbc): Bluetooth SIG low-complexity subband codec audio.truehdโ audio (thd): Dolby TrueHD audio.vc1โ video: SMPTE 421M / VC-1 video.
๐ Examples ๐
- Store raw video frames with the
rawvideomuxer usingffmpeg:
ffmpeg -f lavfi -i testsrc -t 10 -s hd1080p testsrc.yuv
Because the rawvideo muxer doesn't store the information related to size and format, that info has to be provided when demuxing the file: ๐ซถ
ffplay -video_size 1920x1080 -pixel_format rgb24 -f rawvideo testsrc.rgb
๐ง Raw PCM muxers ๐ง
This section covers raw PCM (Pulse-Code Modulation) audio muxers.
They accept a single stream matching the designated codec. They do not store timestamps or metadata. The recognized extension is the same as the muxer name. โจ
It comprises the following muxers. The optional additional extension used to automatically select the muxer from the output extension is also shown in parentheses.
alaw(al) โ PCM A-law.f32beโ PCM 32-bit floating-point big-endian.f32leโ PCM 32-bit floating-point little-endian.f64beโ PCM 64-bit floating-point big-endian.f64leโ PCM 64-bit floating-point little-endian.mulaw(ul) โ PCM mu-law.s16beโ PCM signed 16-bit big-endian.s16leโ PCM signed 16-bit little-endian.s24beโ PCM signed 24-bit big-endian.s24leโ PCM signed 24-bit little-endian.s32beโ PCM signed 32-bit big-endian.s32leโ PCM signed 32-bit little-endian.s8(sb) โ PCM signed 8-bit.u16beโ PCM unsigned 16-bit big-endian.u16leโ PCM unsigned 16-bit little-endian.u24beโ PCM unsigned 24-bit big-endian.u24leโ PCM unsigned 24-bit little-endian.u32beโ PCM unsigned 32-bit big-endian.u32leโ PCM unsigned 32-bit little-endian.u8(ub) โ PCM unsigned 8-bit.vidcโ PCM Archimedes VIDC.
๐ MPEG-1/MPEG-2 program stream muxers ๐
This section covers formats belonging to the MPEG-1 and MPEG-2 Systems family.
The MPEG-1 Systems format (also known as ISO/IEEC 11172-1 or MPEG-1 program stream) has been adopted for the format of media track stored in VCD (Video Compact Disc).
The MPEG-2 Systems standard (also known as ISO/IEEC 13818-1) covers two container formats, one known as transport stream and one known as program stream; only the latter is covered here.
The MPEG-2 program stream format (also known as VOB due to the corresponding file extension) is an extension of MPEG-1 program stream: in addition to supporting different codecs for the audio and video streams, it also stores subtitles and navigation metadata. MPEG-2 program stream has been adopted for storing media streams in SVCD and DVD storage devices.
This section comprises the following muxers. ๐
mpeg(mpg,mpeg) โ MPEG-1 Systems / MPEG-1 program stream muxer.vcdโ MPEG-1 Systems / MPEG-1 program stream (VCD) muxer. ๐ This muxer can be used to generate tracks in the format accepted by VCD (Video Compact Disc) storage devices. It is the same as thempegmuxer with a few differences.vobโ MPEG-2 program stream (VOB) muxer.dvdโ MPEG-2 program stream (DVD VOB) muxer. ๐ This muxer can be used to generate tracks in the format accepted by DVD (Digital Versatile Disc) storage devices. This is the same as thevobmuxer with a few differences.svcd(vob) โ MPEG-2 program stream (SVCD VOB) muxer. ๐ This muxer can be used to generate tracks in the format accepted by SVCD (Super Video Compact Disc) storage devices. This is the same as thevobmuxer with a few differences.
โจ Options โจ
muxraterate โ Set user-defined mux rate expressed as a number of bits/s. If not specified the automatically computed mux rate is employed. Default value is0.preloaddelay โ Set initial demux-decode delay in microseconds. Default value is500000.
๐ฌ MOV/MPEG-4/ISOMBFF muxers ๐ฌ
This section covers formats belonging to the QuickTime / MOV family, including the MPEG-4 Part 14 format and ISO base media file format (ISOBMFF). These formats share a common structure based on the ISO base media file format (ISOBMFF). โจ
The MOV format was originally developed for use with Apple QuickTime. It was later used as the basis for the MPEG-4 Part 1 (later Part 14) format, also known as ISO/IEC 14496-1. That format was then generalized into ISOBMFF, also named MPEG-4 Part 12 format, ISO/IEC 14496-12, or ISO/IEC 15444-12.
It comprises the following muxers. ๐ซถ
3gpโ Third Generation Partnership Project (3GPP) format for 3G UMTS multimedia services.3g2โ Third Generation Partnership Project 2 (3GP2 or 3GPP2) format for 3G CDMA2000 multimedia services, similar to3gpwith extensions and limitations.f4vโ Adobe Flash Video format.ipodโ MPEG-4 audio file format, as MOV/MP4 but limited to contain only audio streams, typically played with the Apple ipod device.ismvโ Microsoft IIS (Internet Information Services) Smooth Streaming Audio/Video (ISMV or ISMA) format. This is based on MPEG-4 Part 14 format with a few incompatible variants, used to stream media files for the Microsoft IIS server.movโ QuickTime player format identified by the".mov"extension.mp4โ MP4 or MPEG-4 Part 14 format.pspโ PlayStation Portable MP4/MPEG-4 Part 14 format variant. This is based on MPEG-4 Part 14 format with a few incompatible variants, used to play files on PlayStation devices.
๐งฉ Fragmentation ๐งฉ
The mov, mp4, and ismv muxers support fragmentation. Normally, a MOV/MP4 file has all the metadata about all packets stored in one location.
This data is usually written at the end of the file, but it can be moved to the start for better playback by adding +faststart to the -movflags, or using the qt-faststart tool.
A fragmented file consists of a number of fragments, where packets and metadata about these packets are stored together. Writing a fragmented file has the advantage that the file is decodable even if the writing is interrupted (while a normal MOV/MP4 is undecodable if it is not properly finished), and it requires less memory when writing very long files (since writing normal MOV/MP4 files stores info about every single packet in memory until the file is closed). The downside is that it is less compatible with other applications. ๐ญ
Fragmentation is enabled by setting one of the options that define how to cut the file into fragments:
frag_durationfrag_sizemin_frag_durationmovflags +frag_keyframemovflags +frag_custom
If more than one condition is specified, fragments are cut when one of the specified conditions is fulfilled. The exception to this is the option min_frag_duration, which has to be fulfilled for any of the other conditions to apply.
โจ Options โจ
brandbrand_string โ overrides the major brand. that's it, that's the whole thing ๐empty_hdlr_namebool โ turn this on and it skips writing the name inside anhdlrbox. default isfalse.encryption_keykey โ sets the media encryption key, in hexadecimal format.encryption_kidkid โ sets the media encryption key identifier, also in hexadecimal format.encryption_schemescheme โ configures the encryption scheme. allowed values arenoneandcenc-aes-ctr.frag_durationduration โ makes fragments that are duration microseconds long.frag_interleavenumber โ interleaves samples within fragments (that's the max number of consecutive samples โ lower means tighter interleaving, but with more overhead ๐ซ ). it's set to0by default.frag_sizesize โ creates fragments containing up to size bytes of payload data.iods_audio_profileprofile โ specifies the iods number for the audio profile atom (from-1to255), default is-1.iods_video_profileprofile โ same energy but for the video profile atom's iods number (from-1to255), default is-1.ism_lookaheadnum_entries โ specifies the number of lookahead entries for ISM files (from0to255), default is0.min_frag_durationduration โ will NOT create fragments shorter than duration microseconds long. setting a floor, bestie โmoov_sizebytes โ reserves space for the moov atom at the beginning of the file instead of sticking it at the end. if the space you reserve isn't enough, muxing will fail ๐ญmov_gammagamma โ specifies the gamma value for the gama atom (a decimal number from0to10), default is0.0, and it must be set together with+ movflags.movflagsflags โ sets the various muxing switches. the following flags can be used:cmafโ write CMAF (Common Media Application Format) compatible fragmented MP4 output.dashโ write DASH (Dynamic Adaptive Streaming over HTTP) compatible fragmented MP4 output.default_base_moofโ similarly to theomit_tfhd_offsetflag, this avoids writing the absolutebase_data_offsetfield in tfhd atoms, but does it by using the newdefault-base-is-moofflag instead. this flag is new from 14496-12:2012. it may make the fragments easier to parse in certain circumstances (avoiding basing track fragment location calculations on the implicit end of the previous track fragment). lowkey a glow-up for parsing โจdelay_moovโ delays writing the initial moov until the first fragment is cut, or until the first fragment flush.disable_chplโ disables Nero chapter markers (chpl atom). normally both Nero chapters and a QuickTime chapter track get written to the file; with this option set, only the QuickTime chapter track will be written. Nero chapters can cause failures when the file is reprocessed with certain tagging programs, like mp3Tag 2.61a and iTunes 11.3 โ most likely other versions are affected as well ๐faststartโ runs a second pass moving the index (moov atom) to the beginning of the file. this operation can take a while, and will not work in various situations such as fragmented output, so it is not enabled by default.frag_customโ lets the caller manually choose when to cut fragments, by callingav_write_frame(ctx, NULL)to write a fragment with the packets written so far. (this is only useful with other applications integrating libavformat, not from ffmpeg.)frag_discontโ signals that the next fragment is discontinuous from earlier ones.frag_every_frameโ fragment at every frame.frag_keyframeโ start a new fragment at each video keyframe.global_sidxโ write a global sidx index at the start of the file.ismlโ create a live smooth streaming feed (for pushing to a publishing point).negative_cts_offsetsโ enables utilization of version 1 of the CTTS box, in which the CTS offsets can be negative. this lets the initial sample have DTS/CTS of zero, and reduces the need for edit lists for some cases such as video tracks with B-frames. additionally, it eases conformance with the DASH-IF interoperability guidelines. (this option is implicitly set when writing ismv (Smooth Streaming) files ๐)omit_tfhd_offsetโ do not write any absolutebase_data_offsetin tfhd atoms. this avoids tying fragments to absolute byte positions in the file/streams.prefer_iccโ if writing a colr atom, prioritise usage of the ICC profile if it exists in the stream packet side data.rtphintโ add RTP hinting tracks to the output file.separate_moofโ write a separate moof (movie fragment) atom for each track. normally packets for all tracks are written in one moof atom (which is slightly more efficient), but with this option set, the muxer writes one moof/mdat pair for each track, making it easier to separate tracks ๐skip_sidxโ skip writing of the sidx atom. when bitrate overhead due to the sidx atom is high, this option could be used for cases where the sidx atom is not mandatory. when theglobal_sidxflag is enabled, this option is ignored.skip_trailerโ skip writing themfra/tfra/mfrotrailer for fragmented files.use_metadata_tagsโ use the mdta atom for metadata.write_colrโ write the colr atom even if the color info is unspecified. this flag is experimental, may be renamed or changed โ do not use it from scripts ๐write_gamaโ write the deprecated gama atom.hybrid_fragmentedโ for recoverability: write the output file as a fragmented file. this allows the intermediate file to be read while it's being written (in particular, if the writing process is aborted uncleanly). when writing is finished, the file is converted to a regular, non-fragmented file, which is more compatible and allows easier and quicker seeking. if writing is aborted, the intermediate file can manually be remuxed to get a regular, non-fragmented file of what had been written into the unfinished file. literally built-in chaos insurance ๐ซถ
movie_timescalescale โ sets the timescale written in the movie header box (mvhd). range is1toINT_MAX. default is1000.rtpflagsflags โ adds RTP hinting tracks to the output file. the following flags can be used:skip_iodsbool โ skips writing the iods atom (default value istrue).use_editlistbool โ uses the edit list (default value isauto).use_stream_ids_as_track_idsbool โ uses stream ids as track ids (default value isfalse).video_track_timescalescale โ sets the timescale used for video tracks. range is0toINT_MAX. if set to0, the timescale is automatically set based on the native stream time base. default is0.write_btrtbool โ forces or disables writing the bitrate box inside the stsd box of a track. that box contains the decoding buffer size (in bytes), the maximum bitrate and the average bitrate for the track. the box will be skipped if none of these values can be computed. default is-1orauto, which will write the box only in MP4 mode.write_prftoption โ writes a producer time reference box (PRFT) with a specified time source for the NTP field in the PRFT box. set the value towallclockto specify the timesource as wallclock time, andptsto specify the timesource as input packets' PTS values.write_tmcdbool โ specifyonto force writing a timecode track,offto disable it, andautoto write a timecode track only for mov and mp4 output (default).
setting the value toptsis applicable only for a live encoding use case, where PTS values are set as wallclock time at the source. for example, an encoding use case with a decklink capture source wherevideo_ptsandaudio_ptsare set toabs_wallclock.
โจ Examples โจ
- push Smooth Streaming content in real time to a publishing point on IIS with the
ismvmuxer usingffmpeg:
ffmpeg -re <<normal input/transcoding options>> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
๐ฎ a64
the A64 Commodore 64 video muxer.
this muxer accepts a single a64_multi or a64_multi5 codec video stream. that's the whole vibe check, retro bestie ๐น๏ธ
๐ ac4
the raw AC-4 audio muxer.
this muxer accepts a single ac4 audio stream.
Options
write_crcbool โ when enabled, writes a CRC checksum for each packet to the output. default isfalse.
๐ป adts
the Audio Data Transport Stream muxer.
it accepts a single AAC stream.
Options
write_id3v2bool โ enable to write ID3v2.4 tags at the start of the stream. default is disabled.write_apetagbool โ enable to write APE tags at the end of the stream. default is disabled.write_mpeg2bool โ enable to set the MPEG version bit in the ADTS frame header to1, which indicates MPEG-2. default is0, which indicates MPEG-4.
๐พ aea
the MD STUDIO audio muxer.
this muxer accepts a single ATRAC1 audio stream with either one or two channels and a sample rate of 44100Hz.
as AEA supports storing the track title, this muxer will also write the title from the stream's metadata to the container ๐
๐ง aiff
the Audio Interchange File Format muxer.
Options
write_id3v2bool โ enables ID3v2 tags writing when set to1. default is0(disabled).id3v2_versionbool โ selects the ID3v2 version to write. currently only version 3 and 4 (aka. ID3v2.3 and ID3v2.4) are supported. the default is version 4.
๐๏ธ alp
High Voltage Software's Lego Racers game audio muxer.
it accepts a single ADPCM_IMA_ALP stream with no more than 2 channels and a sample rate not greater than 44100 Hz.
extensions: tun, pcm
Options
typetype โ sets the file type.
type accepts the following values:
tunโ set the file type as music. must have a sample rate of22050 Hz.pcmโ set the file type as sfx.autoโ set the file type as per the output file extension..pcmresults in typepcm, else typetunis set. (default)
amr ๐ง
3GPP AMR (Adaptive Multi-Rate) audio muxer.
It accepts a single audio stream containing an AMR NB stream.
amv ๐
AMV (Actions Media Video) format muxer.
apm ๐
Ubisoft Rayman 2 APM audio muxer.
It accepts a single ADPCM IMA APM audio stream.
apng ๐ฆ
Animated Portable Network Graphics muxer.
It accepts a single APNG video stream.
Options
final_delaydelay โ force a delay expressed in seconds after the last frame of each repetition. Default value is0.0.playsrepetitions โ specify how many times to play the content.0causes an infinite loop, and with1there is no loop.
Examples
- Use
ffmpegto generate an APNG output with 2 repetitions and a delay of half a second after the first repetition:
ffmpeg -i INPUT -final_delay 0.5 -plays 2 out.apng
argo_asf ๐
Argonaut Games ASF audio muxer.
It accepts a single ADPCM audio stream.
Options
version_majorversion โ override the file major version, specified as an integer. Default value is2.version_minorversion โ override the file minor version, specified as an integer. Default value is1.namename โ embed the file name into the file. If not specified, use the output file name. The name is truncated to8characters.
argo_cvg ๐ธ
Argonaut Games CVG audio muxer.
It accepts a single one-channel ADPCM 22050Hz audio stream.
The loop and reverb options set the corresponding flags in the header, which can be later retrieved to process the audio stream accordingly.
Options
skip_rate_checkbool โ skip the sample rate check (default is"false").loopbool โ set the loop flag (default is"false").reverbboolean โ set the reverb flag (default is"true").
asf, asf_stream ๐ฌ
Advanced / Active Systems (or Streaming) Format audio muxer.
The asf_stream variant should be selected for streaming.
Note that Windows Media Audio (wma) and Windows Media Video (wmv) use this muxer too. ๐
Options
packet_sizesize โ set the muxer packet size as a number of bytes. By tuning this setting you may reduce data fragmentation or muxer overhead depending on your source. Default value is3200, minimum is100, maximum is"64Ki".
ass ๐ฌ
ASS/SSA (SubStation Alpha) subtitles muxer.
It accepts a single ASS subtitles stream.
Options
ignore_readorderbool โ write dialogue events immediately, even if they are out-of-order. Default is"false"; otherwise they are cached until the expected time event is found.
ast ๐
AST (Audio Stream) muxer.
This format is used to play audio on some Nintendo Wii games.
It accepts a single audio stream.
The loopstart and loopend options can be used to define a section of the file to loop for players honoring such options.
Options
loopstartstart โ specify the loop start position expressed in milliseconds, from-1toINT_MAX. If-1is set, then no loop is specified (default-1) and theloopendvalue is ignored.loopendend โ specify the loop end position expressed in milliseconds, from0toINT_MAX. Default is0; if0is set, it assumes the total stream duration.
au ๐ต
SUN AU audio muxer.
It accepts a single audio stream.
avi ๐๏ธ
Audio Video Interleaved muxer.
AVI is a proprietary format developed by Microsoft, and later formally specified through the Open DML specification.
Because of differences in player implementations, it might be required to set some options to make sure that the generated output can be correctly played by the target player.
Options
flipped_raw_rgbbool โ if set to"true", store positive height for raw RGB bitmaps, which indicates the bitmap is stored bottom-up. Note that this option does not flip the bitmap โ that has to be done manually beforehand, e.g. by using thevflipfilter. Default is"false"and indicates the bitmap is stored top down.reserve_index_spacesize โ reserve the specified amount of bytes for the OpenDML master index of each stream within the file header. By default, additional master indexes are embedded within the data packets if there is no space left in the first master index and are linked together as a chain of indexes. This index structure can cause problems for some use cases, e.g. third-party software strictly relying on the OpenDML index specification or when file seeking is slow. Reserving enough index space in the file header avoids these problems.
The required index space depends on the output file size and should be about 16 bytes per gigabyte. When this option is omitted or set to zero, the necessary index space is guessed.
Default value is 0.
write_channel_maskbool โ write the channel layout mask into the audio stream header.
This option is enabled by default. Disabling the channel mask can be useful in specific scenarios, e.g. when merging multiple audio streams into one for compatibility with software that only supports a single audio stream in AVI (see the "amerge" section in the ffmpeg-filters manual).
avif ๐ผ๏ธ
AV1 (Alliance for Open Media Video codec 1) image format muxer.
This muxer stores images encoded using the AV1 codec.
It accepts one or two video streams. In case two video streams are provided, the second one shall contain a single plane storing the alpha mask.
In case more than one image is provided, the generated output is considered an animated AVIF and the number of loops can be specified with the loop option.
This is based on the specification by Alliance for Open Media at url https://aomediacodec.github.io/av1-avif.
Options
loopcount โ number of times to loop an animated AVIF.0specifies an infinite loop; default is0.movie_timescaletimescale โ set the timescale written in the movie header box ("mvhd"). Range is1toINT_MAX. Default is1000.
avm2 โจ
ShockWave Flash (SWF) / ActionScript Virtual Machine 2 (AVM2) format muxer.
It accepts one audio stream, one video stream, or both.
bit ๐ง
G.729 (.bit) file format muxer.
It accepts a single G.729 audio stream.
caf โ
Apple CAF (Core Audio Format) muxer.
It accepts a single audio stream.
codec2 ๐ป
Codec2 audio audio muxer.
It accepts a single codec2 audio stream.
chromaprint ๐ถ
Chromaprint fingerprinter muxers.
To enable compilation of this filter you need to configure FFmpeg with --enable-chromaprint.
This muxer feeds audio data to the Chromaprint library, which generates a fingerprint for the provided audio data. See: https://acoustid.org/chromaprint.
It takes a single signed native-endian 16-bit raw audio stream of at most 2 channels.
Options
algorithmversion โ select the version of the algorithm to fingerprint with. Range is0to4. Version3enables silence detection. Default is1.fp_formatformat โ format to output the fingerprint as. Accepts the following options:base64โ Base64 compressed fingerprint (default)compressedโ Binary compressed fingerprintrawโ Binary raw fingerprint
silence_thresholdthreshold โ threshold for detecting silence. Range is from-1to32767, where-1disables silence detection. Silence detection can only be used with version3of the algorithm.
Silence detection must be disabled for use with the AcoustID service. Default is -1.
crc ๐
CRC (Cyclic Redundancy Check) muxer.
This muxer computes and prints the Adler-32 CRC of all the input audio and video frames. By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before computing the CRC.
The output of the muxer consists of a single line of the form: CRC=0xCRC, where CRC is a hexadecimal number 0-padded to 8 digits containing the CRC for all the decoded input frames.
See also the framecrc muxer.
Examples
- Use
ffmpegto compute the CRC of the input, and store it in the fileout.crc:
ffmpeg -i INPUT -f crc out.crc
- Use
ffmpegto print the CRC to stdout with the command:
ffmpeg -i INPUT -f crc -
- You can select the output format of each frame with
ffmpegby specifying the audio and video codec and format. For example, to compute the CRC of the input audio converted to PCM unsigned 8-bit and the input video converted to MPEG-2 video, use the command:
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
dash ๐
Dynamic Adaptive Streaming over HTTP (DASH) muxer.
This muxer creates segments and manifest files according to the MPEG-DASH standard ISO/IEC 23009-1:2014 and following standard updates.
For more information see:
- ISO DASH Specification:
http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip - WebM DASH Specification:
https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification
This muxer creates an MPD (Media Presentation Description) manifest file and segment files for each stream. Segment files are placed in the same directory of the MPD manifest file.
The segment filename might contain pre-defined identifiers used in the manifest "SegmentTemplate" section as defined in section 5.3.9.4.4 of the standard.
Available identifiers are "$RepresentationID$", "$Number$", "$Bandwidth$", and "$Time$". In addition to the standard identifiers, an ffmpeg-specific "$ext$" identifier is also supported. When specified, ffmpeg will replace "$ext$" in the file name with muxing format's extensions such as "mp4", "webm" etc.
Options
adaptation_setsadaptation_sets โ assign streams to adaptation sets, specified in the MPD manifest"AdaptationSets"section.
An adaptation set contains a set of one or more streams accessed as a single subset, e.g. corresponding streams encoded at different sizes selectable by the user depending on the available bandwidth, or to different audio streams with a different language.
Each adaptation set is specified with the syntax:
id=<index>,streams=<streams>
where index must be a numerical index, and streams is a sequence of ","-separated stream indices. Multiple adaptation sets can be specified, separated by spaces.
To map all video (or audio) streams to an adaptation set, "v" (or "a") can be used as stream identifier instead of IDs.
When no assignment is defined, this defaults to an adaptation set for each stream.
The following optional fields can also be specified:
Okay so, inside adaptation_sets you can also drop these extra keys โ theyโre giving fine-grained control:
descriptorโ defines the descriptor exactly as ISO/IEC 23009-1:2014/Amd.2:2015 says. And bestie, the descriptor string should be a self-closing XML tag.
For example:
<SupplementalProperty schemeIdUri=\"urn:mpeg:dash:srd:2014\" value=\"0,0,0,1,1,2,2\"/>
frag_durationโ overrides the global fragment duration that was set with thefrag_durationoption.frag_typeโ overrides the global fragment type that was set with thefrag_typeoption.seg_durationโ overrides the global segment duration that was set with theseg_durationoption.trick_idโ marks an adaptation set as containing streams meant to be used for Trick Mode for the referenced adaptation set.
A few examples of possible values for the adaptation_sets option follow:
id=0,seg_duration=2,frag_duration=1,frag_type=duration,streams=v id=1,seg_duration=2,frag_type=none,streams=a
id=0,seg_duration=2,frag_type=none,streams=0 id=1,seg_duration=10,frag_type=none,trick_id=0,streams=1
โจ DASH muxer options, continued โจ
dash_segment_type typeโ sets the DASH segment files type. Possible values:autoโ the DASH segment files format will be selected based on the stream codec. This is the default mode.mp4โ the DASH segment files will be in ISOBMFF/MP4 format.webmโ the DASH segment files will be in WebM format.
extra_window_size sizeโ sets the maximum number of segments kept outside of the manifest before they get removed from disk.format_options options_listโ sets container format (mp4/webm) options using a":"-separated list ofkey=valueparameters. Values containing":"special characters must be escaped.frag_duration durationโ sets the length in seconds of fragments within segments. Fractional values can also be set.frag_type typeโ sets the type of interval for fragmentation. Possible values:autoโ set one fragment per segment.every_frameโ fragment at every frame.durationโ fragment at specific time intervals.pframesโ fragment at keyframes and following P-Frame reordering (Video only, experimental).
global_sidx boolโ writes global"SIDX"atom. Applicable only for single file,mp4output, non-streaming mode.hls_master_name file_nameโ HLS master playlist name. Default ismaster.m3u8.hls_playlist boolโ generates HLS playlist files. The master playlist is generated with the filename specified by thehls_master_nameoption. One media playlist file is generated for each stream with filenamesmedia_0.m3u8,media_1.m3u8, etc.http_opts http_optsโ specifies a list of":"-separatedkey=valueoptions to pass to the underlying HTTP protocol. Applicable only for HTTP output.http_persistent boolโ uses persistent HTTP connections. Applicable only for HTTP output.http_user_agent user_agentโ overrides the User-Agent field in the HTTP header. Applicable only for HTTP output.ignore_io_errors boolโ ignores IO errors during open and write. Useful for long-duration runs with network output. This is disabled by default.index_correction boolโ enables or disables segment index correction logic. Applicable only whenuse_templateis enabled anduse_timelineis disabled. This is disabled by default.
When enabled, the logic monitors the flow of segment indexes. If a streamโs segment index value is not at the expected real time position, then the logic corrects that index value.
Typically this logic is needed in live streaming use cases. Network bandwidth fluctuations are common during long-run streaming. Each fluctuation can cause the segment indexes to fall behind the expected real time position.
init_seg_name init_nameโ DASH-templated name to use for the initialization segment. Default is"init-stream$RepresentationID$.$ext$"."$ext$"is replaced with the file name extension specific for the segment format.ldash boolโ enables Low-latency Dash by constraining the presence and values of some elements. This is disabled by default.lhls boolโ enables Low-latency HLS (LHLS). Adds"#EXT-X-PREFETCH"tag with the current segmentโs URI. The hls.js player folks are trying to standardize an open LHLS spec. The draft spec is available athttps://github.com/video-dev/hlsjs-rfcs/blob/lhls-spec/proposals/0001-lhls.md.
This option tries to comply with the above open spec. It enables streaming and hls_playlist options automatically. This is an experimental feature.
Note: This is not Appleโs version of LHLS. See https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis.
master_m3u8_publish_rate segment_intervals_countโ publishes the master playlist repeatedly every after the specified number of segment intervals.max_playback_rate rateโ sets the maximum playback rate indicated as appropriate for the purposes of automatically adjusting playback latency and buffer occupancy during normal playback by clients.media_seg_name segment_nameโ DASH-templated name to use for the media segments. Default is"chunk-stream$RepresentationID$-$Number%05d$.$ext$"."$ext$"is replaced with the file name extension specific for the segment format.method methodโ uses the given HTTP method to create output files. Generally set to"PUT"or"POST".min_playback_rate rateโ sets the minimum playback rate indicated as appropriate for the purposes of automatically adjusting playback latency and buffer occupancy during normal playback by clients.mpd_profile flagsโ sets one or more MPD manifest profiles. Possible values:dashโ MPEG-DASH ISO Base media file format live profile.dvb_dashโ DVB-DASH profile.
Default value is "dash".
remove_at_exit boolโ enables or disables removal of all segments when finished. This is disabled by default.seg_duration durationโ sets the segment length in seconds (fractional value can be set). The value is treated as average segment duration when theuse_templateoption is enabled and theuse_timelineoption is disabled, and as minimum segment duration for all the other use cases.
Default value is 5.
single_file boolโ enables or disables storing all segments in one file, accessed using byte ranges. This is disabled by default.
The name of the single file can be specified with the single_file_name option. If not specified, assume the basename of the manifest file with the output format extension.
single_file_name file_nameโ DASH-templated name to use for the manifest"baseURL"element. Imply that thesingle_fileoption is set totrue. In the template,"$ext$"is replaced with the file name extension specific for the segment format.streaming boolโ enables or disables chunk streaming mode of output. In chunk streaming mode, each frame will be a"moof"fragment which forms a chunk. This is disabled by default.target_latency target_latencyโ sets an intended target latency in seconds for serving (fractional value can be set). Applicable only when thestreamingandwrite_prftoptions are enabled. This is an informative field clients can use to measure the latency of the service.timeout timeoutโ sets timeout for socket I/O operations expressed in seconds (fractional value can be set). Applicable only for HTTP output.update_period periodโ sets the MPD update period, for dynamic content. The unit is second. If set to0, the period is automatically computed.
Default value is 0.
use_template boolโ enables or disables use of"SegmentTemplate"instead of"SegmentList"in the manifest. This is enabled by default.use_timeline boolโ enables or disables use of"SegmentTimeline"within the"SegmentTemplate"manifest section. This is enabled by default.utc_timing_url urlโ URL of the page that will return the UTC timestamp in ISO format, for example"https://time.akamai.com/?iso".window_size sizeโ sets the maximum number of segments kept in the manifest, discarding the oldest one. This is useful for live streaming.
If the value is 0, all segments are kept in the manifest. Default value is 0.
write_prft write_prftโ writes Producer Reference Time elements on supported streams. This also enables writingprftboxes in the underlying muxer. Applicable only when theutc_urloption is enabled. It is set toautoby default, in which case the muxer will attempt to enable it only in modes that require it.
๐ธ Example ๐ธ
Generate a DASH output reading from an input source in realtime using ffmpeg.
Two multimedia streams are generated from the input file, both containing a video stream encoded through libx264, and an audio stream encoded with libfdk_aac. The first multimedia stream contains video with a bitrate of 800k and audio at the default rate, the second with video scaled to 320x170 pixels at 300k and audio resampled at 22005 Hz.
The window_size option keeps only the latest 5 segments with the default duration of 5 seconds.
ffmpeg -re -i <input> -map 0 -map 0 -c:a libfdk_aac -c:v libx264 \
-b:v:0 800k -profile:v:0 main \
-b:v:1 300k -s:v:1 320x170 -profile:v:1 baseline -ar:a:1 22050 \
-bf 1 -keyint_min 120 -g 120 -sc_threshold 0 -b_strategy 0 \
-use_timeline 1 -use_template 1 -window_size 5 \
-adaptation_sets "id=0,streams=v id=1,streams=a" \
-f dash /path/to/out.mpd
๐ฌ daud
D-Cinema audio muxer.
It accepts a single 6-channels audio stream resampled at 96000 Hz encoded with the pcm_24daud codec.
Example
Use ffmpeg to mux input audio to a 5.1 channel layout resampled at 96000Hz:
ffmpeg -i INPUT -af aresample=96000,pan=5.1 slow.302
For ffmpeg versions before 7.0 you might have to use the asetnsamples filter to limit the muxed packet size, because this format does not support muxing packets larger than 65535 bytes (3640 samples). For newer ffmpeg versions audio is automatically packetized to 36000 byte (2000 sample) packets.
๐ฌ dv
DV (Digital Video) muxer.
It accepts exactly one dvvideo video stream and at most two pcm_s16 audio streams. More constraints are defined by the property of the video, which must correspond to a DV video supported profile, and on the framerate.
Example
Use ffmpeg to convert the input:
ffmpeg -i INPUT -s:v 720x480 -pix_fmt yuv411p -r 29.97 -ac 2 -ar 48000 -y out.dv
๐ ffmetadata
The FFmpeg metadata muxer, bestie. It writes the streams' metadata out in the ffmetadata format.
Wanna know all about that format? Check the Metadata chapter, it's right there. โจ
Example
Say you wanna pull the metadata out of an input file into a metadata.ffmeta file in ffmetadata format โ do this:
ffmpeg -i INPUT -f ffmetadata metadata.ffmeta
๐งต fifo
The FIFO (First-In First-Out) muxer, and honestly it's giving main character energy.
What the fifo pseudo-muxer does is let you separate encoding from muxing โ it uses a first-in-first-out queue and runs the actual muxer in a separate thread. ๐ฆ
It's especially iconic when you pair it with the tee muxer, and it lets you send data to several destinations that each have different reliability / writing speed / latency. No cap.
So which target muxer does it use? Either it picks one from the output name, or you tell it directly with the fifo_format option.
Now, what happens when the queue fills up or the output just... fails (like when a packet can't be written to the output)? That's selectable, and you've got options:
- Output can be transparently restarted, with a configurable delay between retries, based on real time or on the time of the processed stream.
- Encoding can be blocked during a temporary failure, or it can keep going and transparently drop packets when the FIFO queue fills up.
โ ๏ธ API users, listen up: the callback functions ("interrupt_callback","io_open"and"io_close") used inside its"AVFormatContext"must be thread-safe. Not optional, not a vibe, just facts. ๐
Options
attempt_recoverybool โ if a failure happens, try to recover the output. This is especially useful with network output, because it lets you restart streaming transparently. Default is"false".drop_pkts_on_overflowbool โ if it's set to"true"and the fifo queue fills up, packets get dropped instead of blocking the encoder. That means you can keep streaming without delaying the input โ at the cost of losing part of the stream. Default is"false", so normally the encoder gets blocked until the muxer processes some packets and nothing is lost. ๐ซถfifo_formatformat_name โ set the format name. Handy when it can't be guessed from the output name suffix.format_optsoptions โ set format options for the underlying muxer. Muxer options go in as a list ofkey=valuepairs separated by':'.max_recovery_attemptscount โ cap the number of successive unsuccessful recovery attempts, after which the output fails permanently. Default is0, which means unlimited.queue_sizesize โ the size of the queue, as a number of packets. Default is60.recover_any_errorbool โ if"true", recovery is attempted no matter what type of error caused the failure. Default is"false", and in that case certain (usually permanent) errors won't trigger recovery even whenattempt_recoveryis"true".recovery_wait_streamtimebool โ if"false", real time is what's used when waiting for the recovery attempt (i.e. recovery gets attempted after the time set byrecovery_wait_time). If"true", the time of the processed stream is taken into account instead (i.e. recovery is attempted after discarding the packets corresponding torecovery_wait_time). Default is"false".recovery_wait_timeduration โ how long to wait, in seconds, before the next recovery attempt after an unsuccessful one. Default is5.restart_with_keyframebool โ whether to wait for a keyframe after recovering from a queue overflow or failure. Default is"false".timeshiftduration โ buffer that many packets and delay writing the output. Heads up: yourqueue_sizevalue has to be big enough to store the packets for the timeshift. At the end of the input, the fifo buffer is flushed at realtime speed. โณ
Example
Okay so here's the flex: stream to an RTMP server with ffmpeg, keep processing the stream at real-time rate even if there's a temporary failure (network outage moment ๐ญ), and try to recover the stream every second, indefinitely:
ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv \
-drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 \
-map 0:v -map 0:a rtmp://example.com/live/stream_name
๐ฎ film_cpk
The Sega film (.cpk) muxer. This format was used as the internal format for several Sega games โ retro girlies rise ๐น๏ธโจ
Want the lore on the Sega film file format? Go here: http://wiki.multimedia.cx/index.php?title=Sega_FILM.
It accepts at maximum one cinepak or raw video stream, and at maximum one audio stream. That's the limit, don't push it.
๐๏ธ filmstrip
The Adobe Filmstrip muxer. Several Adobe tools use this format to store a generated filmstrip export. It accepts a single raw video stream.
๐ญ fits
The Flexible Image Transport System (FITS) muxer โ yes, that's the astrology-girlie of image formats, it's literally used to store astronomical data. ๐โญ
More info? Here: https://fits.gsfc.nasa.gov.
๐ flac
The Raw FLAC audio muxer. It accepts exactly one FLAC audio stream. And as a lil bonus, you can add images with the attached_pic disposition. ๐ผ๏ธ
Options
write_headerbool โ write the file header if set to"true". Default is"true".
Example
Use ffmpeg to store the audio stream from an input file, plus a couple of pictures on attached_pic disposition:
ffmpeg -i INPUT -i pic1.png -i pic2.jpg -map 0:a -map 1 -map 2 -disposition:v attached_pic OUTPUT
๐ flv
The Adobe Flash Video Format muxer. Flash era representation, honestly.
Options
flvflagsflags โ the possible values are:aac_seq_header_detectโ place the AAC sequence header based on the audio stream data.no_sequence_endโ disable the sequence end tag.no_metadataโ disable the metadata tag.no_duration_filesizeโ disable duration and filesize in the metadata when they're equal to zero at the end of the stream. (Used for a non-seekable living stream.)add_keyframe_indexโ used to facilitate seeking; especially for HTTP pseudo streaming.
๐ framecrc
The per-packet CRC (Cyclic Redundancy Check) testing format.
This muxer computes and prints an Adler-32 CRC for every audio and video packet. By default, audio frames get converted to signed 16-bit raw audio and video frames get converted to raw video before the CRC is computed.
The output is one line per audio and video packet, like this:
<stream_index>, <packet_dts>, <packet_pts>, <packet_duration>, <packet_size>, 0x<CRC>
CRC is a hexadecimal number, 0-padded out to 8 digits, holding the CRC of the packet. ๐
Examples
Say you wanna compute the CRC of the audio and video frames in INPUT, converted to raw audio and video packets, and stash it in out.crc:
ffmpeg -i INPUT -f framecrc out.crc
Wanna print it to stdout instead? Run:
ffmpeg -i INPUT -f framecrc -
And with ffmpeg you can pick which output format the audio and video frames get encoded to before the per-packet CRC is computed, just by specifying the audio and video codec. For example, to compute the CRC of each decoded input audio frame converted to PCM unsigned 8-bit, and of each decoded input video frame converted to MPEG-2 video, use:
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
Also go peek at the crc muxer. ๐
#๏ธโฃ framehash
The per-packet hash testing format.
This muxer computes and prints a cryptographic hash for every audio and video packet. Which means you can do packet-by-packet equality checks without having to individually do a binary comparison on each one. Obsessed with the efficiency honestly.
By default, audio frames get converted to signed 16-bit raw audio and video frames to raw video before the hash is computed โ but you can also use the output of explicit conversions to other codecs. It uses the SHA-256 cryptographic hash function by default, but supports several other algorithms.
Output is one line for each audio and video packet, like this:
<stream_index>, <packet_dts>, <packet_pts>, <packet_duration>, <packet_size>, <hash>
hash is a hexadecimal number representing the computed hash for the packet.
hashalgorithm โ use the cryptographic hash function named by the string algorithm. Supported values include"MD5","murmur3","RIPEMD128","RIPEMD160","RIPEMD256","RIPEMD320","SHA160","SHA224","SHA256"(default),"SHA512/224","SHA512/256","SHA384","SHA512","CRC32"and"adler32".
Examples
To compute the SHA-256 hash of the audio and video frames in INPUT, converted to raw audio and video packets, and store it in the file out.sha256:
ffmpeg -i INPUT -f framehash out.sha256
To print the info to stdout using the MD5 hash function:
ffmpeg -i INPUT -f framehash -hash md5 -
Also check out the hash muxer. โจ
๐ framemd5
The per-packet MD5 testing format.
It's a variant of the framehash muxer โ except unlike that one, it defaults to the MD5 hash function.
Examples
To compute the MD5 hash of the audio and video frames in INPUT, converted to raw audio and video packets, and store it in the file out.md5:
ffmpeg -i INPUT -f framemd5 out.md5
To print the info to stdout:
ffmpeg -i INPUT -f framemd5 -
Also see the framehash and md5 muxers.
๐ฆ gif
The Animated GIF muxer. The internet's love language, fr.
โ ๏ธ Heads up: the GIF format has a very large time base โ the delay between two frames can't be smaller than one centi second. That's just the format's whole deal.
Options
loopbool โ how many times to loop the output. Use-1for no loop,0for looping indefinitely (default). ๐final_delaydelay โ force the delay (expressed in centiseconds) after the last frame. Every frame ends with a delay until the next frame. Default is-1, a special value that tells the muxer to reuse the previous delay. If you're looping, you might wanna customize this value to mark a pause, for instance.
Example
Encode a gif that loops 10 times, with a 5 second delay between the loops:
ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
Note 1: if you wanna extract the frames into separate GIF files, you need to force theimage2muxer:ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
๐ผ gxf
The General eXchange Format (GXF) muxer.
It accepts at most one video stream with codec mjpeg, or mpeg1video, or mpeg2video, or dvvideo with resolution 512x480 or 608x576, and several audio streams with rate 48000Hz and codec pcm16_le.
hash โจ the vibe-checker โจ
Hash testing format. No cap, this one is so underrated.
This muxer computes and prints a cryptographic hash of all the input audio and video frames. It's giving "do these two files actually match" energy โ used for equality checks without having to do a whole entire binary comparison. Like, why compare every byte when you can just compare the vibe (the hash)? ๐
By default, audio frames get converted to signed 16-bit raw audio and video frames to raw video before computing the hash, but you can also use the output of explicit conversions to other codecs. Timestamps are, respectfully, ignored. ๐ซถ It uses the SHA-256 cryptographic hash function by default, but supports several other algorithms, iykyk.
The output of the muxer consists of a single line of the form: algo=hash, where algo is a short string representing the hash function used, and hash is a hexadecimal number representing the computed hash.
hash algorithm
Use the cryptographic hash function specified by the string algorithm. Supported values include "MD5", "murmur3", "RIPEMD128", "RIPEMD160", "RIPEMD256", "RIPEMD320", "SHA160", "SHA224", "SHA256" (default), "SHA512/224", "SHA512/256", "SHA384", "SHA512", "CRC32" and "adler32". That's a whole roster, bestie โ pick your fighter. ๐ฆ
Examples
To compute the SHA-256 hash of the input converted to raw audio and video, and store it in the file out.sha256:
ffmpeg -i INPUT -f hash out.sha256
To print an MD5 hash to stdout use the command:
ffmpeg -i INPUT -f hash -hash md5 -
See also the framehash muxer. ๐
hds ๐ฌ (Adobe's little adaptive-streaming moment)
HTTP Dynamic Streaming (HDS) muxer.
HTTP dynamic streaming, or HDS, is an adaptive bitrate streaming method developed by Adobe. HDS delivers MP4 video content over HTTP connections. HDS can be used for on-demand streaming or live streaming.
This muxer creates an .f4m (Adobe Flash Media Manifest File) manifest, an .abst (Adobe Bootstrap File) for each stream, and segment files in a directory specified as the output.
โ ๏ธ These needs to be accessed by an HDS player through HTTPS for it to be able to perform playback on the generated stream. HTTPS only, bestie โ the player will simply not come to the party otherwise.
Options
extra_window_sizeint โ number of fragments kept outside of the manifest before removing from diskmin_frag_durationmicroseconds โ minimum fragment duration (in microseconds), default value is 1 second (10000000)remove_at_exitbool โ remove all fragments when finished when set to"true"window_sizeint โ number of fragments kept in the manifest, if set to a value different from0. By default all segments are kept in the output directory.
Example
Use ffmpeg to generate HDS files to the output.hds directory in real-time rate:
ffmpeg -re -i INPUT -f hds -b:v 200k output.hds
hls ๐ the main character muxer ๐
Apple HTTP Live Streaming muxer that segments MPEG-TS according to the HTTP Live Streaming (HLS) specification. She's literally iconic, everyone knows her.
It creates a playlist file, and one or more segment files. The output filename specifies the playlist filename.
By default, the muxer creates a file for each segment produced. These files have the same name as the playlist, followed by a sequential number and a .ts extension.
๐ Make sure to require a closed GOP when encoding and to set the GOP size to fit your segment time constraint. Do not skip this, fr fr โ the segments will get feral otherwise.
For example, to convert an input file with ffmpeg:
ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8
This example will produce the playlist, out.m3u8, and segment files: out0.ts, out1.ts, out2.ts, etc.
See also the segment muxer, which provides a more generic and flexible implementation of a segmenter, and can be used to perform HLS segmentation.
Options
hls_init_time duration Set the initial target segment length. Default value is 0.
duration must be a time duration specification, see the Time duration section in the ffmpeg-utils(1) manual.
Segment will be cut on the next key frame after this time has passed on the first m3u8 list. After the initial playlist is filled, ffmpeg will cut segments at duration equal to hls_time.
hls_time duration Set the target segment length. Default value is 2.
duration must be a time duration specification, see the Time duration section in the ffmpeg-utils(1) manual. Segment will be cut on the next key frame after this time has passed.
hls_list_size size Set the maximum number of playlist entries. If set to 0 the list file will contain all the segments. Default value is 5.
hls_delete_threshold size Set the number of unreferenced segments to keep on disk before "hls_flags delete_segments" deletes them. Increase this to allow continue clients to download segments which were recently referenced in the playlist. Default value is 1, meaning segments older than hls_list_size+1 will be deleted.
hls_start_number_source source Start the playlist sequence number ("#EXT-X-MEDIA-SEQUENCE") according to the specified source. Unless hls_flags single_file is set, it also specifies source of starting sequence numbers of segment and subtitle filenames. In any case, if hls_flags append_list is set and read playlist sequence number is greater than the specified start sequence number, then that value will be used as start value.
It accepts the following values:
generic(default) โ Set the start numbers according to thestart_numberoption value.epochโ Set the start number as the seconds since epoch (1970-01-01 00:00:00).epoch_usโ Set the start number as the microseconds since epoch (1970-01-01 00:00:00).datetimeโ Set the start number based on the current date/time asYYYYmmddHHMMSS. e.g.20161231235759.
start_number number Start the playlist sequence number ("#EXT-X-MEDIA-SEQUENCE") from the specified number when hls_start_number_source value is generic. (This is the default case.) Unless hls_flags single_file is set, it also specifies starting sequence numbers of segment and subtitle filenames. Default value is 0.
hls_allow_cache bool Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
hls_base_url baseurl Append baseurl to every entry in the playlist. Useful to generate playlists with absolute paths.
๐ Note that the playlist sequence number must be unique for each segment and it is not to be confused with the segment filename sequence number which can be cyclic, for example if the wrap option is specified. Two different numbers, bestie โ do not mix them up.
hls_segment_filename filename Set the segment filename. Unless the hls_flags option is set with single_file, filename is used as a string format with the segment number appended.
For example:
ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
will produce the playlist, out.m3u8, and segment files: file000.ts, file001.ts, file002.ts, etc.
filename may contain a full path or relative path specification, but only the file name part without any path will be contained in the m3u8 segment list. Should a relative path be specified, the path of the created segment files will be relative to the current working directory. When strftime_mkdir is set, the whole expanded value of filename will be written into the m3u8 segment list.
When var_stream_map is set with two or more variant streams, the filename pattern must contain the string "%v", and this string will be expanded to the position of variant stream index in the generated segment file names. Must contain "%v" โ not optional, she'll refuse to work without it.
For example:
ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
-map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
-hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8
will produce the playlists segment file sets: file_0_000.ts, file_0_001.ts, file_0_002.ts, etc. and file_1_000.ts, file_1_001.ts, file_1_002.ts, etc.
The string "%v" may be present in the filename or in the last directory name containing the file, but only in one of them. (Additionally, %v may appear multiple times in the last sub-directory or filename.) If the string %v is present in the directory name, then sub-directories are created after expanding the directory name pattern. This enables creation of segments corresponding to different variant streams in subdirectories.
For example:
ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
-map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
-hls_segment_filename 'vs%v/file_%03d.ts' vs%v/out.m3u8
will produce the playlists segment file sets: vs0/file_000.ts, vs0/file_001.ts, vs0/file_002.ts, etc. and vs1/file_000.ts, vs1/file_001.ts, vs1/file_002.ts, etc.
strftime bool Use strftime() on filename to expand the segment filename with localtime. The segment number is also available in this mode, but to use it, you need to set second_level_segment_index in the hls_flag and %%d will be the specifier.
For example:
ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8
will produce the playlist, out.m3u8, and segment files: file-20160215-1455569023.ts, file-20160215-1455569024.ts, etc. Note: On some systems/environments, the %s specifier is not available. See strftime() documentation. iykyk, platform stuff happens.
For example:
ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8
will produce the playlist, out.m3u8, and segment files: file-20160215-0001.ts, file-20160215-0002.ts, etc.
strftime_mkdir bool Used together with strftime, it will create all subdirectories which are present in the expanded values of option hls_segment_filename.
For example:
ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8
will create a directory 201560215 (if it does not exist), and then produce the playlist, out.m3u8, and segment files: 20160215/file-20160215-1455569023.ts, 20160215/file-20160215-1455569024.ts, etc. (yes the manpage really says 201560215 there, we are not fixing it, we are simply reporting it ๐)
For example:
ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8
...will create a directory hierarchy 2016/02/15 (if any of them don't already exist, she's not gonna yell at you about it), and then produce the playlist, out.m3u8, and segment files:
2016/02/15/file-20160215-1455569023.ts,
2016/02/15/file-20160215-1455569024.ts, etc.
hls_segment_options options_listโ sets output format options using a:-separated list ofkey=valueparameters. Values that contain:special characters have to be escaped ๐hls_key_info_file key_info_fileโ uses the info in key_info_file for segment encryption, bestie. The first line of key_info_file specifies the key URI written to the playlist โ that key URL is what gets used to access the encryption key during playback. The second line specifies the path to the key file used to obtain the key during the encryption process, and that key file is read as a single packed array of 16 octets in binary format. The optional third line specifies the initialization vector (IV) as a hexadecimal string, used instead of the segment sequence number (the default) for encryption. Changes to key_info_file will result in segment encryption with the new key/IV and an entry in the playlist for the new key URI/IV ifhls_flags periodic_rekeyis enabled ๐
Key info file format:
<key URI>
<key file path>
<IV> (optional)
Example key URIs:
http://server/file.key
/path/to/file.key
file.key
Example key file paths:
file.key
/path/to/file.key
Example IV:
0123456789ABCDEF0123456789ABCDEF
Key info file example:
http://server/file.key
/path/to/file.key
0123456789ABCDEF0123456789ABCDEF
Example shell script:
#!/bin/sh
BASE_URL=${1:-'.'}
openssl rand 16 > file.key
echo $BASE_URL/file.key > file.keyinfo
echo file.key >> file.keyinfo
echo $(openssl rand -hex 16) >> file.keyinfo
ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
-hls_key_info_file file.keyinfo out.m3u8
hls_enc boolโ enable (1) or disable (0) the AES128 encryption. When it's enabled, every segment generated gets encrypted and the encryption key is saved as playlist name.key๐hls_enc_key keyโ specify a 16-octet key to encrypt the segments with. By default it's randomly generated, so if you don't say anything she picks for you โจhls_enc_key_url keyurlโ if set, keyurl is prepended instead of baseurl to the key filename in the playlist.hls_enc_iv ivโ specify the 16-octet initialization vector for every segment instead of the autogenerated ones.hls_segment_type flagsโ possible values:mpegtsโ output segment files in MPEG-2 Transport Stream format. This is compatible with all HLS versions ๐ซถfmp4โ output segment files in fragmented MP4 format, similar to MPEG-DASH.fmp4files may be used in HLS version 7 and above.
hls_fmp4_init_filename filenameโ set filename for the fragment files header file; the default filename isinit.mp4.
When strftime is enabled, filename is expanded to the segment filename with localtime.
For example:
ffmpeg -i in.nut -hls_segment_type fmp4 -strftime 1 -hls_fmp4_init_filename "%s_init.mp4" out.m3u8
will produce init like this 1602678741_init.mp4 ๐
hls_fmp4_init_resend boolโ resend init file after m3u8 file refresh every time, default is0.
When var_stream_map is set with two or more variant streams, the filename pattern must contain the string "%v" โ this string specifies the position of the variant stream index in the generated init file names. The string "%v" may be present in the filename or in the last directory name containing the file. If the string is present in the directory name, then sub-directories are created after expanding the directory name pattern. This enables creation of init files corresponding to different variant streams in subdirectories ๐ธ
hls_flags flagsโ possible values:single_fileโ if this flag is set, the muxer will store all segments in a single MPEG-TS file, and will use byte ranges in the playlist. HLS playlists generated this way will have the version number4.
For example:
ffmpeg -i in.nut -hls_flags single_file out.m3u8
will produce the playlist, out.m3u8, and a single segment file, out.ts.
delete_segmentsโ segment files removed from the playlist are deleted after a period of time equal to the duration of the segment plus the duration of the playlist.append_listโ append new segments into the end of the old segment list, and remove the"#EXT-X-ENDLIST"from the old segment list.round_durationsโ round the duration info in the playlist file segment info to integer values, instead of using floating point. If there are no other features requiring higher HLS versions being used, then this will allowffmpegto output a HLS version 2 m3u8 โจdiscont_startโ add the"#EXT-X-DISCONTINUITY"tag to the playlist, before the first segment's information.omit_endlistโ do not append the"EXT-X-ENDLIST"tag at the end of the playlist.periodic_rekeyโ the file specified by"hls_key_info_file"will be checked periodically and updates to the encryption info will be detected. Be sure to replace this file atomically, including the file containing the AES encryption key โ ๏ธ no cap, do it atomically.independent_segmentsโ add the"#EXT-X-INDEPENDENT-SEGMENTS"tag to playlists that has video segments and when all the segments of that playlist are guaranteed to start with a key frame.iframes_onlyโ add the"#EXT-X-I-FRAMES-ONLY"tag to playlists that has video segments and can play only I-frames in the"#EXT-X-BYTERANGE"mode.split_by_timeโ allow segments to start on frames other than key frames. This improves behavior on some players when the time between key frames is inconsistent, but may make things worse on others, and can cause some oddities during seeking ๐ฌ This flag should be used with thehls_timeoption.program_date_timeโ generate"EXT-X-PROGRAM-DATE-TIME"tags.second_level_segment_indexโ make it possible to use segment indexes as%%din thehls_segment_filenameoption expression besides date/time values whenstrftimeoption is on. To get fixed width numbers with trailing zeroes,%%0xdformat is available where x is the required width.second_level_segment_sizeโ make it possible to use segment sizes (counted in bytes) as%%sinhls_segment_filenameoption expression besides date/time values whenstrftimeis on. To get fixed width numbers with trailing zeroes,%%0xsformat is available where x is the required width.second_level_segment_durationโ make it possible to use segment duration (calculated in microseconds) as%%tinhls_segment_filenameoption expression besides date/time values whenstrftimeis on. To get fixed width numbers with trailing zeroes,%%0xtformat is available where x is the required width.
For example:
ffmpeg -i sample.mpeg \
-f hls -hls_time 3 -hls_list_size 5 \
-hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \
-strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8
will produce segments like this: segment_20170102194334_0003_00122200_0000003000000.ts, segment_20170102194334_0004_00120072_0000003000000.ts etc. ๐ฆ iconic naming honestly.
temp_fileโ write segment data tofilename.tmpand rename tofilenameonly once the segment is complete.
A webserver serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments before they have been added to the m3u8 playlist.
This flag also affects how m3u8 playlist files are created. If this flag is set, all playlist files will be written into a temporary file and renamed after they are complete, similarly as segments are handled. But playlists with "file" protocol and with hls_playlist_type type other than vod are always written into a temporary file regardless of this flag.
Master playlist files specified with master_pl_name, if any, with "file" protocol, are always written into temporary file regardless of this flag if master_pl_publish_rate value is other than zero ๐
hls_playlist_type typeโ if type isevent, emit"#EXT-X-PLAYLIST-TYPE:EVENT"in the m3u8 header. This forceshls_list_sizeto0; the playlist can only be appended to.
If type is vod, emit "#EXT-X-PLAYLIST-TYPE:VOD" in the m3u8 header. This forces hls_list_size to 0; the playlist must not change. periodt, it's frozen ๐
method methodโ use the given HTTP method to create the hls files.
For example:
ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8
will upload all the mpegts segment files to the HTTP server using the HTTP PUT method, and update the m3u8 files every "refresh" times using the same method. Note that the HTTP server must support the given method for uploading files ๐
http_user_agent agentโ overrideUser-Agentfield in HTTP header. Applicable only for HTTP output.var_stream_map stream_mapโ specify a map string defining how to group the audio, video and subtitle streams into different variant streams. The variant stream groups are separated by space.
Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are the keys to specify audio, video and subtitle streams respectively. Allowed values are 0 to 9 (limited just based on practical usage) ๐
okay so bestie, when there are two or more variant streams, the output filename pattern must contain the string %v โ thatโs the little slot that tells ffmpeg where to put the variant stream index in the output media playlist filenames. The string %v may be present in the filename or in the last directory name containing the file. If the string is present in the directory name, then sub-directories are created after expanding the directory name pattern. This enables creation of variant streams in subdirectories. ๐
โจ
a few examples follow ๐
- Create two hls variant streams. The first variant stream will contain video stream of bitrate
1000kand audio stream of bitrate64k, and the second variant stream will contain video stream of bitrate256kand audio stream of bitrate32k. Here, two media playlist with file namesout_0.m3u8andout_1.m3u8will be created.
ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
-map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
http://example.com/live/out_%v.m3u8
- If you want something meaningful text instead of indexes in result names, you may specify names for each or some of the variants. The following example will create two hls variant streams as in the previous one. But here, the two media playlist with file names
out_my_hd.m3u8andout_my_sd.m3u8will be created.
ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
-map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0,name:my_hd v:1,a:1,name:my_sd" \
http://example.com/live/out_%v.m3u8
- Create three hls variant streams. The first variant stream will be a video only stream with video bitrate
1000k, the second variant stream will be an audio only stream with bitrate64k, and the third variant stream will be a video only stream with bitrate256k. Here, three media playlist with file namesout_0.m3u8,out_1.m3u8andout_2.m3u8will be created.
ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \
-map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \
http://example.com/live/out_%v.m3u8
- Create the variant streams in subdirectories. Here, the first media playlist is created at
http://example.com/live/vs_0/out.m3u8and the second one athttp://example.com/live/vs_1/out.m3u8.
ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
-map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \
http://example.com/live/vs_%v/out.m3u8
- Create two audio only and two video only variant streams. In addition to the
"#EXT-X-STREAM-INF"tag for each variant stream in the master playlist, the"#EXT-X-MEDIA"tag is also added for the two audio only variant streams and they are mapped to the two video only variant streams with audio group names'aud_low'and'aud_high'. By default, a single hls variant containing all the encoded streams is created.
ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k \
-map 0:a -map 0:a -map 0:v -map 0:v -f hls \
-var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
-master_pl_name master.m3u8 \
http://example.com/live/out_%v.m3u8
- Create two audio only and one video only variant streams. In addition to the
"#EXT-X-STREAM-INF"tag for each variant stream in the master playlist, the"#EXT-X-MEDIA"tag is also added for the two audio only variant streams and they are mapped to the one video only variant streams with audio group name'aud_low', and the audio group have default stat is NO or YES. By default, a single hls variant containing all the encoded streams is created.
ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
-map 0:a -map 0:a -map 0:v -f hls \
-var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \
-master_pl_name master.m3u8 \
http://example.com/live/out_%v.m3u8
- Create two audio only and one video only variant streams, but this time with languages. In addition to the
"#EXT-X-STREAM-INF"tag for each variant stream in the master playlist, the"#EXT-X-MEDIA"tag is also added for the two audio only variant streams and they are mapped to the one video only variant streams with audio group name'aud_low', and the audio group have default stat is NO or YES, and one audio have and language is namedENG, the other audio language is namedCHN. By default, a single hls variant containing all the encoded streams is created.
ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \
-map 0:a -map 0:a -map 0:v -f hls \
-var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \
-master_pl_name master.m3u8 \
http://example.com/live/out_%v.m3u8
- Create a single variant stream. Add the
"#EXT-X-MEDIA"tag with"TYPE=SUBTITLES"in the master playlist with webvtt subtitle group name'subtitle'and optional subtitle name, e.g.'English'. Make sure the input file has one text subtitle stream at least.
ffmpeg -y -i input_with_subtitle.mkv \
-b:v:0 5250k -c:v h264 -pix_fmt yuv420p -profile:v main -level 4.1 \
-b:a:0 256k \
-c:s webvtt -c:a mp2 -ar 48000 -ac 2 -map 0:v -map 0:a:0 -map 0:s:0 \
-f hls -var_stream_map "v:0,a:0,s:0,sgroup:subtitle,sname:English" \
-master_pl_name master.m3u8 -t 300 -hls_time 10 -hls_init_time 4 -hls_list_size \
10 -master_pl_publish_rate 10 -hls_flags \
delete_segments+discont_start+split_by_time ./tmp/video.m3u8
cc_stream_map cc_stream_map ๐ฌ
Map string which specifies different closed captions groups and their attributes. The closed captions stream groups are separated by space.
Expected string format is like this "ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....". 'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional attribute.
The closed captions groups configured using this option are mapped to different variant streams by providing the same 'ccgroup' name in the var_stream_map string.
For example:
ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
-a53cc:0 1 -a53cc:1 1 \
-map 0:v -map 0:a -map 0:v -map 0:a -f hls \
-cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
-var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
-master_pl_name master.m3u8 \
http://example.com/live/out_%v.m3u8
will add two "#EXT-X-MEDIA" tags with "TYPE=CLOSED-CAPTIONS" in the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it will add "CLOSED-CAPTIONS" attribute with group name 'cc' for the two output variant streams.
If var_stream_map is not set, then the first available ccgroup in cc_stream_map is mapped to the output variant stream.
For example:
ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
-cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
-master_pl_name master.m3u8 \
http://example.com/live/out.m3u8
this will add "#EXT-X-MEDIA" tag with "TYPE=CLOSED-CAPTIONS" in the master playlist with group name 'cc', language 'en' (english) and INSTREAM-ID 'CC1'. Also, it will add "CLOSED-CAPTIONS" attribute with group name 'cc' for the output variant stream.
master_pl_namenameโ Create HLS master playlist with the given name. ๐
For example:
ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8
creates an HLS master playlist with name master.m3u8 which is published at http://example.com/live/.
master_pl_publish_ratecountโ Publish master play list repeatedly every after specified number of segment intervals.
For example:
ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \
-hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8
creates an HLS master playlist with name master.m3u8 and keeps publishing it repeatedly every after 30 segments i.e. every after 60s.
http_persistentboolโ Use persistent HTTP connections. Applicable only for HTTP output.timeouttimeoutโ Set timeout for socket I/O operations. Applicable only for HTTP output.ignore_io_errorsboolโ Ignore IO errors during open, write and delete. Useful for long-duration runs with network output.headersheadersโ Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output.
๐ iamf ๐
Immersive Audio Model and Formats (IAMF) muxer. โจ
IAMF is used to provide immersive audio content for presentation on a wide range of devices in both streaming and offline applications. These applications include internet audio streaming, multicasting/broadcasting services, file download, gaming, communication, virtual and augmented reality, and others. In these applications, audio may be played back on a wide range of devices, e.g., headphones, mobile phones, tablets, TVs, sound bars, home theater systems, and big screens.
This format was promoted and designed by Alliance for Open Media. ๐ซถ
For more information about this format, see https://aomedia.org/iamf/.
๐ ico ๐ฆ
ICO file muxer.
Microsoft's icon file format (ICO) has some strict limitations that should be noted: ๐
- Size cannot exceed 256 pixels in any dimension
- Only BMP and PNG images can be stored
- If a BMP image is used, it must be one of the following pixel formats:
BMP bit-depth mapping, bestie โ BMP Bit Depth โ FFmpeg Pixel Format, and the vibe check says match these exactly:
1bitโpal84bitโpal88bitโpal816bitโrgb555le24bitโbgr2432bitโbgra
Also, two little rules that are not optional:
- If a BMP image is used, it must use the
BITMAPINFOHEADERDIB header. - If a PNG image is used, it must use the
rgbapixel format.
ilbc ๐
Internet Low Bitrate Codec (iLBC) raw muxer.
It accepts a single ilbc audio stream. Thatโs the whole assignment, periodt.
image2, image2pipe ๐ผ๏ธ
Image file muxer.
The image2 muxer writes video frames to image files.
The output filenames are specified by a pattern, which can be used to produce sequentially numbered series of files. The pattern may contain the string %d or %0Nd; that string specifies the position of the characters representing a numbering in the filenames. If the form %0Nd is used, the string representing the number in each filename is 0-padded to N digits. The literal character % can be specified in the pattern with the string %%.
If the pattern contains %d or %0Nd, the first filename of the file list specified will contain the number 1, and all the following numbers will be sequential.
The pattern may contain a suffix which is used to automatically determine the format of the image files to write.
For example, the pattern img-%03d.bmp will specify a sequence of filenames of the form img-001.bmp, img-002.bmp, ..., img-010.bmp, etc. The pattern img%%-%d.jpg will specify a sequence of filenames of the form img%-1.jpg, img%-2.jpg, ..., img%-10.jpg, etc.
The image muxer supports the .Y.U.V image file format. This format is special in that each image frame consists of three files, for each of the YUV420P components. To read or write this image file format, specify the name of the .Y file. The muxer will automatically open the .U and .V files as required.
The image2pipe muxer accepts the same options as the image2 muxer, but ignores the pattern verification and expansion, as it is supposed to write to the command output rather than to an actual stored file.
Options โจ
frame_ptsbool โ If set to1, expand the filename with the packet PTS (presentation time stamp). Default value is0.start_numbercount โ Start the sequence from the specified number. Default value is1.updatebool โ If set to1, the filename will always be interpreted as just a filename, not a pattern, and the corresponding file will be continuously overwritten with new images. Default value is0.strftimebool โ If set to1, expand the filename with date and time information fromstrftime(). Default value is0.atomic_writingbool โ Write output to a temporary file, which is renamed to target filename once writing is completed. Default is disabled.protocol_optsoptions_list โ Set protocol options as a:-separatedlist ofkey=valueparameters. Values containing the:special character must be escaped.
Examples ๐
- Use
ffmpegfor creating a sequence of filesimg-001.jpeg,img-002.jpeg, ..., taking one image every second from the input video:
ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg'
Note that withffmpeg, if the format is not specified with the-foption and the output filename specifies an image file format, theimage2muxer is automatically selected, so the previous command can be written as:
ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg'
Note also that the pattern must not necessarily contain%dor%0Nd, for example to create a single image fileimg.jpegfrom the start of the input video you can employ the command:
ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
- The
strftimeoption allows you to expand the filename with date and time information. Check the documentation of thestrftime()function for the syntax.
To generate image files from the strftime() %Y-%m-%d_%H-%M-%S pattern, the following ffmpeg command can be used:
ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
- Set the file name with current frameโs PTS:
ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg
- Publish contents of your desktop directly to a WebDAV server every second:
ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts method=PUT http://example.com/desktop.jpg
ircam ๐ป
Berkeley / IRCAM / CARL Sound Filesystem (BICSF) format muxer.
The Berkeley/IRCAM/CARL Sound Format, developed in the 1980s, is a result of the merging of several different earlier sound file formats and systems including the csound system developed by Dr Gareth Loy at the Computer Audio Research Lab (CARL) at UC San Diego, the IRCAM sound file system developed by Rob Gross and Dan Timis at the Institut de Recherche et Coordination Acoustique / Musique in Paris and the Berkeley Fast Filesystem.
It was developed initially as part of the Berkeley/IRCAM/CARL Sound Filesystem, a suite of programs designed to implement a filesystem for audio applications running under Berkeley UNIX. It was particularly popular in academic music research centres, and was used a number of times in the creation of early computer-generated compositions.
This muxer accepts a single audio stream containing PCM data.
ivf ๐ฆ
On2 IVF muxer.
IVF was developed by On2 Technologies (formerly known as Duck Corporation), to store internally developed codecs.
This muxer accepts a single vp8, vp9, or av1 video stream.
jacosub ๐
JACOsub subtitle format muxer.
This muxer accepts a single jacosub subtitles stream.
For more information about the format, see http://unicorn.us.com/jacosub/jscripts.html.
kvag ๐ฎ
Simon & Schuster Interactive VAG muxer.
This custom VAG container is used by some Simon & Schuster Interactive games such as "Real War", and "Real War: Rogue States".
This muxer accepts a single adpcm_ima_ssi audio stream.
lc3 ๐ง
Bluetooth SIG Low Complexity Communication Codec audio (LC3), or ETSI TS 103 634 Low Complexity Communication Codec plus (LC3plus).
This muxer accepts a single lc3 audio stream.
lrc ๐ค
LRC lyrics file format muxer.
LRC (short for LyRiCs) is a computer file format that synchronizes song lyrics with an audio file, such as MP3, Vorbis, or MIDI.
This muxer accepts a single subrip or text subtitles stream.
Metadata ๐ท๏ธ
The following metadata tags are converted to the format corresponding metadata:
titlealbumartistauthorcreatorencoderencoder_version
If encoder_version is not explicitly set, it is automatically set to the libavformat version.
matroska ๐
Matroska container muxer.
This muxer implements the matroska and webm container specs.
Metadata ๐ท๏ธ
The recognized metadata settings in this muxer are:
titleโ Set title name provided to a single track. This gets mapped to theFileDescriptionelement for a stream written as attachment.languageโ Specify the language of the track in the Matroska languages form.
The language can be either the 3 letters bibliographic ISO-639-2 (ISO 639-2/B) form (like fre for French), or a language code mixed with a country code for specialities in languages (like fre-ca for Canadian French).
stereo_modeโ Set stereo 3D video layout of two views in a single video track.
The following values are recognized:
monoโ video is not stereoleft_rightโ Both views are arranged side by side, Left-eye view is on the leftbottom_topโ Both views are arranged in top-bottom orientation, Left-eye view is at bottomtop_bottomโ Both views are arranged in top-bottom orientation, Left-eye view is on topcheckerboard_rlโ Each view is arranged in a checkerboard interleaved pattern, Left-eye view being firstcheckerboard_lrโ Each view is arranged in a checkerboard interleaved pattern, Right-eye view being firstrow_interleaved_rlโ Each view is constituted by a row based interleaving, Right-eye view is first rowrow_interleaved_lrโ Each view is constituted by a row based interleaving, Left-eye view is first rowcol_interleaved_rlโ Both views are arranged in a column based interleaving manner, Right-eye view is first columncol_interleaved_lrโ Both views are arranged in a column based interleaving manner, Left-eye view is first columnanaglyph_cyan_redโ All frames are in anaglyph format viewable through red-cyan filtersright_leftโ Both views are arranged side by side, Right-eye view is on the leftanaglyph_green_magentaโ All frames are in anaglyph format viewable through green-magenta filtersblock_lrโ Both eyes laced in one Block, Left-eye view is firstblock_rlโ Both eyes laced in one Block, Right-eye view is first
For example a 3D WebM clip can be created using the following command line:
ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
Options โจ
reserve_index_spacesize โ By default, this muxer writes the index for seeking (called cues in Matroska terms) at the end of the file, because it cannot know in advance how much space to leave for the index at the beginning of the file. However for some use cases โ e.g. streaming where seeking is possible but slow โ it is useful to put the index at the beginning of the file.
If this option is set to a non-zero value, the muxer will reserve size bytes of space in the file header and then try to write the cues there when the muxing finishes. If the reserved space does not suffice, no Cues will be written, the file will be finalized and writing the trailer will return an error. A safe size for most use cases should be about 50kB per hour of video.
Note that cues are only written if the output is seekable and this option will have no effect if it is not.
cues_to_frontbool โ If set, the muxer will write the index at the beginning of the file by shifting the main data if necessary. This can be combined withreserve_index_spacein which case the data is only shifted if the initially reserved space turns out to be insufficient.
This option is ignored if the output is unseekable.
cluster_size_limitsize โ caps how many bytes can go into one cluster. If you don't set it, the limit just auto-sets itself to a sensible hardcoded fixed value, no stress ๐cluster_time_limitduration โ caps how many milliseconds can go into one cluster. Same deal, if you don't set it, a sensible hardcoded fixed value swoops in automatically โจdashbool โ makes a WebM file that conforms to the WebM DASH spec. Default is"false", so it's off unless you say otherwise ๐dash_track_numberindex โ sets the track number for the DASH stream. Default is1, bestie.livebool โ writes files assuming it's a live stream. Default is"false".allow_raw_vfwbool โ lets raw VFW mode through. Default is"false".flipped_raw_rgbbool โ if you set it to"true", it stores a positive height for raw RGB bitmaps, which means the bitmap is stored bottom-up. Careful though: this option does not flip the bitmap for you, you gotta do that yourself beforehand, e.g. with thevflipfilter. Default is"false", which means the bitmap is stored top down ๐ซถwrite_crc32bool โ writes a CRC32 element inside every Level 1 element. Default is"true". Heads up: this option gets ignored for WebM ๐default_modemode โ controls how theFlagDefaultof the output tracks gets set. It's the thing that influences which tracks players should play by default. Default mode ispassthrough.inferโ every track with disposition default gets theFlagDefaultset. Plus, for each type of track (audio, video or subtitle), if there's no track with disposition default of that type, then the first track of that type gets marked as default (if one exists). This makes sure the default flag is set in a sensible way even if the input came from containers that don't even have the concept of default tracks. Iconic behaviour honestly ๐infer_no_subsโ same asinfer, except if there's no subtitle track with disposition default, then no subtitle track gets marked as default. Simple as that.passthroughโ in this mode theFlagDefaultis set if and only if theAV_DISPOSITION_DEFAULTflag is set in the disposition of the corresponding stream. No guessing, no extras.
๐ฆ md5
The MD5 testing format, bestie. It's a variant of the hash muxer โ but unlike that one, it defaults to using the MD5 hash function ๐
See also the hash and framemd5 muxers.
๐ธ Examples ๐ธ
- To compute the MD5 hash of the input converted to raw audio and video, and store it in the file
out.md5:
ffmpeg -i INPUT -f md5 out.md5
- To print the MD5 hash to stdout:
ffmpeg -i INPUT -f md5 -
๐ mcc
A muxer for MacCaption MCC files โ it supports MCC versions 1.0 and 2.0. MCC files store VANC data, which can include closed captions (EIA-608 and CEA-708), ancillary time code, pan-scan data, etc. So much packed in there fr fr โจ
๐ Options ๐
The muxer options are:
override_time_code_rateโ overrides the"Time Code Rate"value in the output. By default it tries to deduce it from the stream's"time_base", which โ ngl โ often doesn't work ๐ญuse_u_aliasโ uses the"U"alias for the byte sequenceE1h 00h 00h 00h. It's disabled by default because some.mccfiles disagree on whether it has 2 or 3 zero bytes ๐mcc_versionโ the MCC file format version. Must be either1or2, defaults to2.creation_programโ the creation program. Defaults to this version of FFmpeg ๐ซถcreation_timeโ the creation time. Defaults to the current time.
๐ Examples ๐
- Extract a MXF
SMPTE_436M_ANCstream from a MXF file and write it to a MCC file at 30 fps:
ffmpeg -i input.mxf -c copy -map 0:d -override_time_code_rate 30 out.mcc
- Extract EIA-608/CTA-708 closed captions from a
.mp4file and write them to a MCC file at 29.97 fps:
ffmpeg -f lavfi -i "movie=input.mp4[out+subcc]" -c:s copy -map 0:s -override_time_code_rate 30000/1001 out.mcc
๐ฌ microdvd
MicroDVD subtitle format muxer, periodt. This muxer accepts a single microdvd subtitles stream โ one, that's it, don't get greedy ๐
๐ mmf
Synthetic music Mobile Application Format (SMAF) format muxer โจ
SMAF is a music data format specified by Yamaha for portable electronic devices, such as mobile phones and personal digital assistants. Very retro of them, we love to see it.
This muxer accepts a single adpcm_yamaha audio stream.
๐ mp3
The MP3 muxer writes a raw MP3 stream with the following optional features, and honestly the list is giving main character energy:
- An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and 2.4 are supported, and the
id3v2_versionprivate option controls which one you get (3or4). Settingid3v2_versionto0disables the ID3v2 header completely ๐ซถ
The muxer supports writing attached pictures (APIC frames) to the ID3v2 header. You supply the pictures to the muxer as a video stream with a single packet. There can be any number of those streams, and each one will correspond to a single APIC frame. The stream metadata tags title and comment map to APIC description and picture type respectively. See http://id3.org/id3v2.4.0-frames for the allowed picture types.
Important caveat bestie: the APIC frames must be written at the beginning, so the muxer will buffer the audio frames until it gets all the pictures. So it's advised to provide the pictures as soon as possible to avoid excessive buffering ๐ญ
- A Xing/LAME frame right after the ID3v2 header (if present). It's enabled by default, but it will only be written if the output is seekable. The
write_xingprivate option can be used to disable it. The frame contains various information that may be useful to the decoder, like the audio duration or encoder delay โญ - A legacy ID3v1 tag at the end of the file (disabled by default). You can enable it with the
write_id3v1private option, but since its capabilities are very limited, its usage is not recommended ๐
๐ Examples ๐
Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
To attach a picture to an mp3 file, select both the audio and the picture stream with map:
ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
-metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
Write a "clean" MP3 without any extra features:
ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
๐บ mpegts
MPEG transport stream muxer, the absolute workhorse of the group chat ๐โจ
This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
The recognized metadata settings in the mpegts muxer are "service_provider" and "service_name". If they're not set, the default for "service_provider" is FFmpeg and the default for "service_name" is Service01.
๐ Options ๐
The muxer options are:
mpegts_transport_stream_idinteger โ sets thetransport_stream_id. This identifies a transponder in DVB. Default is0x0001.mpegts_original_network_idinteger โ sets theoriginal_network_id. This is a unique identifier of a network in DVB. Its main use is in the unique identification of a service through the pathOriginal_Network_ID, Transport_Stream_ID. Default is0x0001.mpegts_service_idinteger โ sets theservice_id, also known asprogramin DVB. Default is0x0001.mpegts_service_typeinteger โ sets the programservice_type. Default is"digital_tv". Accepts the following options:hex_valueโ any hexadecimal value between0x01and0xffas defined in ETSI 300 468.digital_tvโ Digital TV service.digital_radioโ Digital Radio service.teletextโ Teletext service.advanced_codec_digital_radioโ Advanced Codec Digital Radio service.mpeg2_digital_hdtvโ MPEG2 Digital HDTV service.advanced_codec_digital_sdtvโ Advanced Codec Digital SDTV service.advanced_codec_digital_hdtvโ Advanced Codec Digital HDTV service.
mpegts_pmt_start_pidinteger โ sets the first PID for PMTs. Default is0x1000, minimum is0x0020, maximum is0x1ffa. Bestie, this option has no effect in m2ts mode, where the PMT PID is fixed at0x0100๐mpegts_start_pidinteger โ sets the first PID for elementary streams. Default is0x0100, minimum is0x0020, maximum is0x1ffa. Also no effect in m2ts mode, where the elementary stream PIDs are fixed.mpegts_m2ts_modeboolean โ enables m2ts mode if set to1. Default value is-1, which disables m2ts mode.muxrateinteger โ sets a constant muxrate. Default is VBR.pes_payload_sizeinteger โ sets the minimum PES packet payload in bytes. Default is2930.mpegts_flagsflags โ sets mpegts flags. Accepts the following options:resend_headersโ reemit PAT/PMT before writing the next packet.latmโ use LATM packetization for AAC.pat_pmt_at_framesโ reemit PAT and PMT at each video frame.system_bโ conform to System B (DVB) instead of System A (ATSC).initial_discontinuityโ mark the initial packet of each stream as discontinuity.nitโ emit NIT table.omit_raiโ disable writing of random access indicator.
mpegts_copytsboolean โ preserve original timestamps, if the value is set to1. Default value is-1, which results in shifting timestamps so that they start from 0 โจomit_video_pes_lengthboolean โ omit the PES packet length for video packets. Default is1(true).pcr_periodinteger โ overrides the default PCR retransmission time in milliseconds. Default is-1, which means the PCR interval gets determined automatically:20ms is used for CBR streams, and the highest multiple of the frame duration which is less than100ms is used for VBR streams. It's giving "we'll handle it, don't worry" ๐pat_periodduration โ maximum time in seconds between PAT/PMT tables. Default is0.1.sdt_periodduration โ maximum time in seconds between SDT tables. Default is0.5.nit_periodduration โ maximum time in seconds between NIT tables. Default is0.5.tables_versioninteger โ sets PAT, PMT, SDT and NIT version (default0, valid values are from0to31, inclusively). This option lets you update the stream structure so that a standard consumer may detect the change ๐ฅ To do so, reopen the output"AVFormatContext"(in case of API usage) or restart the ffmpeg instance, cyclically changing thetables_versionvalue:
ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
...
ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
...
Example
Okay so here's the whole metadata glow-up in one go, bestie โ watch how every PID and ID gets its own little moment ๐
ffmpeg -i file.mpg -c copy \
-mpegts_original_network_id 0x1122 \
-mpegts_transport_stream_id 0x3344 \
-mpegts_service_id 0x5566 \
-mpegts_pmt_start_pid 0x1500 \
-mpegts_start_pid 0x150 \
-metadata service_provider="Some provider" \
-metadata service_name="Some Channel" \
out.ts
mxf, mxf_d10, mxf_opatom
The MXF muxer, bestie. Broadcast royalty ๐
Options
Here's the muxer option lineup:
store_user_commentsbool โ tells it whether user comments should be stored when they're available, or literally never. Fun fact: IRT D-10 doesn't allow user comments at all ๐ญ So the default is to write them formxfandmxf_opatom, but not formxf_d10.
null
The null muxer โ it's giving "no thoughts, head empty" but make it a container ๐ธ
This one doesn't generate any output file whatsoever. What's it even for?? Testing and benchmarking, obviously. That's the whole vibe.
Say you wanna benchmark decoding with ffmpeg, you'd run:
ffmpeg -benchmark -i INPUT -f null out.null
Heads up! That command above does not read or write theout.nullfile at all โ but like, specifying the output file is still required by theffmpegsyntax. Rules are rules, iykyk.
Alternatively you can write the command like this instead:
ffmpeg -benchmark -i INPUT -f null -
nut
-syncpointsflags โ changes up the syncpoint usage in nut:defaultโ uses the normal low-overhead seeking aids. Chill, standard, does the job โจnoneโ doesn't use syncpoints at all, so less overhead, but the stream becomes non-seekable;
Use of this option is not recommended, because the resulting files are very damage sensitive and seeking is not possible ๐ฌ Also, in general the overhead from syncpoints is negligible. Note though, -C<write_index> 0 can be used to disable all growing data tables, which lets you mux endless streams with limited memory and without these disadvantages. Slay.
timestampedโ extends the syncpoint with a wallclock field.
Real talk: thenoneandtimestampedflags are experimental. ๐
-write_indexbool โ writes the index at the end. Default behavior is to write an index, mwah ๐
ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
ogg
The Ogg container muxer. Classic icon, no notes ๐
-page_durationduration โ your preferred page duration, measured in microseconds. The muxer will try to create pages that are approximately duration microseconds long. This is your lil' dial for compromising between seek granularity and container overhead. Default is1second. A value of0fills all segments, making pages as large as possible. A value of1effectively uses 1 packet-per-page in most situations, which gives you small seek granularity at the cost of extra container overhead. Trade-offs, bestie ๐-serial_offsetvalue โ the serial value that the streams' serial number gets set from. Set it to different and sufficiently large values and you're guaranteed that the produced ogg files can be safely chained together. Obsessed with a safe chain ๐
rcwt
RCWT (Raw Captions With Time) is a format native to ccextractor โ you know, the commonly used open source tool for processing 608/708 Closed Captions (CC) sources. It can be used to archive the original extracted CC bitstream, and to produce a source file for later processing or conversion. The format allows for interoperability between ccextractor and FFmpeg, it's simple to parse, and you can use it to create a backup of the CC presentation. We love a low-effort, high-reward format ๐ซถ
This muxer implements the spec as of March 2024, which has been stable and unchanged since April 2014. Ten years no changes, that's main character energy fr.
So this muxer will have some nuances compared to the way ccextractor muxes RCWT. No compatibility issues have been observed so far when processing the output with ccextractor as a result of this, but mileage may vary and outputs will not be a bit-exact match. Close enough is close enough ๐
A free specification of RCWT can be found here: <https://github.com/CCExtractor/ccextractor/blob/master/docs/BINARY_FILE_FORMAT.TXT>
Examples
- Extract Closed Captions to RCWT using lavfi:
ffmpeg -f lavfi -i "movie=INPUT.mkv[out+subcc]" -map 0:s:0 -c:s copy -f rcwt CC.rcwt.bin
segment, stream_segment, ssegment
The basic stream segmenter. Chopping things into pieces, but make it cute โ๏ธโจ
This muxer outputs streams into a bunch of separate files of nearly fixed duration. You can set the output filename pattern in a fashion similar to image2, or by using a strftime template if the strftime option is enabled.
stream_segment is a variant of the muxer used to write to streaming output formats โ meaning formats that don't require global headers โ and it's recommended for outputting to, say, MPEG transport stream segments. ssegment is a shorter alias for stream_segment. Same vibe, less typing ๐
Every segment starts with a keyframe of the selected reference stream, which you set through the reference_stream option.
Real talk: if you want accurate splitting for a video file, you need to make the input key frames correspond to the exact splitting times the segmenter expects โ otherwise the segment muxer will start the new segment with the key frame it finds next after the specified start time. No cap, it just does its own thing ๐ญ
The segment muxer works best with a single constant frame rate video. That's its moment.
Optionally it can generate a list of the created segments, by setting the option segment_list. The list type is specified by the segment_list_type option. The entry filenames in the segment list are set by default to the basename of the corresponding segment files.
Also go look at the hls muxer, which provides a more specific implementation for HLS segmentation. Whole different girl ๐
Options
The segment muxer supports the following options:
increment_tc1|0 โ if set to1, increment the timecode between each segment. If you pick this, the input needs to have a timecode in the first video stream. Default value is0.reference_streamspecifier โ sets the reference stream, as specified by the string specifier. If specifier is set to"auto", the reference is chosen automatically. Otherwise it must be a stream specifier (see the ``Stream specifiers'' chapter in theffmpegmanual) which specifies the reference stream. Default value is"auto".segment_formatformat โ override the inner container format. By default it's guessed from the filename extension.segment_format_optionsoptions_list โ set output format options using a:-separated list ofkey=valueparameters. Values containing the:special character must be escaped. Escape responsibly ๐ซถsegment_listname โ generate also a listfile named name. If it's not specified, no listfile is generated.segment_list_flagsflags โ set flags affecting the segment list generation. It currently supports the following flags:cacheโ allow caching (only affects M3U8 list files).liveโ allow live-friendly file generation.
segment_list_sizesize โ update the list file so it contains at most size segments. If0, the list file will contain all the segments. Default value is0.segment_list_entry_prefixprefix โ prepend prefix to each entry. Useful for generating absolute paths. By default no prefix is applied.segment_list_typetype โ select the listing format. The following values are recognized:flatโ generate a flat list for the created segments, one segment per line.csv,extโ generate a list for the created segments, one segment per line, each line matching the format (comma-separated values):
<segment_filename>,<segment_start_time>,<segment_end_time>
segment_filename is the name of the output file generated by the muxer according to the provided pattern. CSV escaping (according to RFC4180) is applied if required.
segment_start_time and segment_end_time specify the segment start and end time expressed in seconds.
A list file with the suffix ".csv" or ".ext" will auto-select this format.
extis deprecated in favor ofcsv. Usecsv, bestie, it's the it-girl now ๐
ffconcatโ generate an ffconcat file for the created segments. The resulting file can be read using the FFmpeg concat demuxer. A list file with the suffix".ffcat"or".ffconcat"will auto-select this format.m3u8โ generate an extended M3U8 file, version 3, compliant with <http://tools.ietf.org/id/draft-pantos-http-live-streaming>. A list file with the suffix".m3u8"will auto-select this format.
If not specified, the type is guessed from the list file name suffix. Detective mode ๐
segment_timetime โ set segment duration to time; the value must be a duration specification. Default value is"2". See also thesegment_timesoption.
Note that splitting may not be accurate, unless you force the reference stream key-frames at the given time. See the introductory notice and the examples below. It's giving "approximately" ๐ญ
min_seg_durationtime โ set minimum segment duration to time; the value must be a duration specification. This prevents the muxer from ending segments at a duration below this value. Only effective withsegment_time. Default value is"0".segment_atclocktime1|0 โ if set to"1", split at regular clock time intervals starting from 00:00 o'clock. The time value specified insegment_timeis used for setting the length of the splitting interval.
For example, with segment_time set to "900" this makes it possible to create files at 12:00 o'clock, 12:15, 12:30, etc. Clean, scheduled, punctual icon behavior ๐
Default value is "0".
segment_clocktime_offsetduration โ delays the segment splitting times by the specified duration when usingsegment_atclocktime.
For example, with segment_time set to "900" and segment_clocktime_offset set to "300", this makes it possible to create files at 12:05, 12:20, 12:35, etc. Fashionably late โจ
Default value is "0".
segment_clocktime_wrap_durationduration โ forces the segmenter to only start a new segment if a packet reaches the muxer within the specified duration after the segmenting clock time. This way you can make the segmenter more resilient to backward local time jumps, like leap seconds or the transition to standard time from daylight savings time. Built different, honestly ๐
Default is the maximum possible duration, which means it starts a new segment regardless of the elapsed time since the last clock time.
segment_time_deltadelta โ sets the accuracy time for picking a segment start time, bestie, and itโs a duration spec. Default is"0".
When delta is set, a key-frame starts a new segment if its PTS satisfies this exact relation:
PTS >= start_time - time_delta
This is lowkey iconic when youโre splitting video content that always splits at GOP boundaries, especially if a key frame lands just before your specified split time.
Itโs especially useful with the ffmpeg force_key_frames option. The key frame times from force_key_frames might not be set super accurately because of rounding, so a key frame time can end up just before the specified time. For constant frame rate videos, 1/(2*frame_rate) should handle the worst-case mismatch between the specified time and the time set by force_key_frames.
segment_timestimes โ specify a list of split points. times is a comma-separated list of duration specs, in increasing order. Also checksegment_time, bestie.segment_framesframes โ specify a list of split video frame numbers. frames is a comma-separated list of integer numbers, in increasing order.
This one says: start a new segment whenever a reference stream key frame is found and the sequential number (starting from 0) of the frame is greater than or equal to the next value in the list.
segment_wraplimit โ wrap around the segment index once it hits limit. Cute little loop-de-loop.segment_start_numbernumber โ sets the sequence number of the first segment. Defaults to0.strftime1|0โ use thestrftimefunction to define the name of the new segments to write. If this is selected, the output segment name must contain astrftimefunction template. Default value is0.break_non_keyframes1|0โ if enabled, segments can start on frames that arenโt keyframes. This improves behavior on some players when the time between keyframes is inconsistent, but it may make things worse on others, and it can cause some oddities during seeking. Defaults to0.reset_timestamps1|0โ reset timestamps at the beginning of each segment so every segment starts with near-zero timestamps. Itโs meant to make playback of the generated segments easier. May not work with some combinations of muxers/codecs. Set to0by default.initial_offsetoffset โ timestamp offset to apply to the output packet timestamps. The argument must be a time duration specification, and it defaults to0.write_empty_segments1|0โ if enabled, write an empty segment if there are no packets during the period a segment would usually span. Otherwise, the segment gets filled with the next packet written. Defaults to0.
Make sure to require a closed GOP when encoding and to set the GOP size to fit your segment time constraint. No cap, this one matters.
๐ Examples ๐
- Remux the content of file
in.mkvto a list of segmentsout-000.nut,out-001.nut, etc., and write the list of generated segments toout.list:
ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut
- Segment input and set output format options for the output segments:
ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4
- Segment the input file according to the split points specified by the
segment_timesoption:
ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 out%03d.nut
- Use the ffmpeg
force_key_framesoption to force key frames in the input at the specified location, together with the segment optionsegment_time_deltato account for possible roundings operated when setting key frame times:
ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
-f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
In order to force key frames on the input file, transcoding is required.
- Segment the input file by splitting the input file according to the frame numbers sequence specified with the
segment_framesoption:
ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
- Convert the
in.mkvto TS segments using thelibx264andaacencoders:
ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts
- Segment the input file, and create an M3U8 live playlist (can be used as live HLS source):
ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
-segment_list_flags +live -segment_time 10 out%03d.mkv
๐ smoothstreaming ๐
The Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with a conventional web server. Very โit just worksโ energy.
window_sizeโ specify the number of fragments kept in the manifest. Default0(keep all).extra_window_sizeโ specify the number of fragments kept outside of the manifest before removing them from disk. Default5.lookahead_countโ specify the number of lookahead fragments. Default2.min_frag_durationโ specify the minimum fragment duration (in microseconds). Default5000000.remove_at_exitโ specify whether to remove all fragments when finished. Default0(do not remove).
โจ streamhash โจ
Per stream hash testing format. This muxer computes and prints a cryptographic hash of all the input frames, on a per-stream basis. Itโs for equality checks without having to do a complete binary comparison. Obsessed.
By default audio frames are converted to signed 16-bit raw audio and video frames to raw video before computing the hash, but the output of explicit conversions to other codecs can also be used. Timestamps are ignored. It uses the SHA-256 cryptographic hash function by default, but supports several other algorithms.
The output of the muxer is one line per stream, like this: streamindex,streamtype,algo=hash, where streamindex is the index of the mapped stream, streamtype is a single character indicating the type of stream, algo is a short string representing the hash function used, and hash is a hexadecimal number representing the computed hash.
hashalgorithm โ use the cryptographic hash function specified by the string algorithm. Supported values include"MD5","murmur3","RIPEMD128","RIPEMD160","RIPEMD256","RIPEMD320","SHA160","SHA224","SHA256"(default),"SHA512/224","SHA512/256","SHA384","SHA512","CRC32"and"adler32".
๐ Examples ๐
To compute the SHA-256 hash of the input converted to raw audio and video, and store it in the file out.sha256:
ffmpeg -i INPUT -f streamhash out.sha256
To print an MD5 hash to stdout use the command:
ffmpeg -i INPUT -f streamhash -hash md5 -
See also the hash and framehash muxers.
๐ tee ๐
The tee muxer can be used to write the same data to several outputs, such as files or streams. It can be used, for example, to stream a video over a network and save it to disk at the same time. Literally the multitasking queen.
It is different from specifying several outputs to the ffmpeg command-line tool. With the tee muxer, the audio and video data will be encoded only once. With conventional multiple outputs, multiple encoding operations in parallel are initiated, which can be a very expensive process. The tee muxer is not useful when using the libavformat API directly because it is then possible to feed the same packets to several muxers directly.
Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select output streams. So all streams intended for output must be specified using -map. See the examples below.
Some encoders may need different options depending on the output format; the auto-detection of this can not work with the tee muxer, so they need to be explicitly specified. The main example is the global_header flag.
The slave outputs are specified in the file name given to the muxer, separated by |. If any of the slave name contains the | separator, leading or trailing spaces or any special character, those must be escaped (see the "Quoting and escaping" section in the ffmpeg-utils(1) manual).
๐ Options ๐
use_fifobool โ if set to1, slave outputs will be processed in separate threads using thefifomuxer. This allows you to compensate for different speed/latency/reliability of outputs and setup transparent recovery. By default this feature is turned off.fifo_optionsโ options to pass tofifopseudo-muxer instances. Seefifo.
Muxer options can be specified for each slave by prepending them as a list of key=value pairs separated by :, between square brackets. If the options values contain a special character or the : separator, they must be escaped; note that this is a second level escaping.
The following special options are also recognized:
fโ specify the format name. Required if it cannot be guessed from the output URL.bsfs[/spec]โ specify a list of bitstream filters to apply to the specified output.
It is possible to specify to which streams a given bitstream filter applies, by appending a stream specifier to the option separated by /. spec must be a stream specifier (see Format stream specifiers).
If the stream specifier is not specified, the bitstream filters will be applied to all streams in the output. This will cause that output operation to fail if the output contains streams to which the bitstream filter cannot be applied e.g. h264_mp4toannexb being applied to an output containing an audio stream.
Options for a bitstream filter must be specified in the form of opt=value.
Several bitstream filters can be specified, separated by ,.
use_fifobool โ this allows you to overrideteemuxeruse_fifooption for an individual slave muxer.fifo_optionsโ this allows you to overrideteemuxerfifo_optionsfor an individual slave muxer. Seefifo.selectโ select the streams that should be mapped to the slave output, specified by a stream specifier. If not specified, this defaults to all the mapped streams. This will cause that output operation to fail if the output format does not accept all mapped streams.
You may use multiple stream specifiers separated by commas (,) e.g.: a:0,v.
onfailโ tells ffmpeg what to do when an output in this tee group dies ๐. Set it to"abort"(that's the default) or"ignore"."abort"means the whole process fails the moment this slave output fails."ignore"means the failure gets shrugged off and the other outputs keep vibing along, totally unaffected ๐ซถ.
Example time โจ
๐ Examples
- Encode something and both archive it in a WebM file and stream it as MPEG-TS over UDP:
ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
"archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
- Same thing as above, but keep streaming even if the output to the local file fails (say your local drive fills up ๐ญ):
ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
"[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
- Use
ffmpegto encode the input and send the output to three different destinations. Thedump_extrabitstream filter is used to add extradata information to all the output video keyframes packets, as requested by the MPEG-TS format. Theselectoption is applied toout.aacin order to make it contain only audio packets ๐ง:
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
-f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
- As above, but select only stream
"a:1"for the audio output. Note that a second level escaping must be performed, as":"is a special character used to separate options โ so yeah, double-escape or it will not slay ๐:
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac
-f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
๐ฆ webm_chunk
WebM Live Chunk Muxer, bestie ๐.
This muxer writes out WebM headers and chunks as separate files, which can be consumed by clients that support WebM Live streams via DASH.
Options
This muxer supports the following options:
chunk_start_indexโ the index of the first chunk (defaults to0).headerโ filename of the header, i.e. where the initialization data will be written.audio_chunk_durationโ duration of each audio chunk in milliseconds (defaults to5000).
Example
ffmpeg -f v4l2 -i /dev/video0 \
-f alsa -i hw:0 \
-map 0:0 \
-c:v libvpx-vp9 \
-s 640x360 -keyint_min 30 -g 30 \
-f webm_chunk \
-header webm_live_video_360.hdr \
-chunk_start_index 1 \
webm_live_video_360_%d.chk \
-map 1:0 \
-c:a libvorbis \
-b:a 128k \
-f webm_chunk \
-header webm_live_audio_128.hdr \
-chunk_start_index 1 \
-audio_chunk_duration 1000 \
webm_live_audio_128_%d.chk
๐ webm_dash_manifest
WebM DASH Manifest muxer, iconic behaviour only ๐.
This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML. It also supports manifest generation for DASH live streams ๐ฅ.
For more information see:
- WebM DASH Specification: <https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification>
- ISO DASH Specification: <http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip>
Options
This muxer supports the following options:
adaptation_setsโ this option has the following syntax:"id=x,streams=a,b,c id=y,streams=d,e"wherexandyare the unique identifiers of the adaptation sets anda,b,c,dandeare the indices of the corresponding audio and video streams. Any number of adaptation sets can be added using this option ๐.liveโ set this to1to create a live stream DASH Manifest. Default:0.chunk_start_indexโ start index of the first chunk. This will go in thestartNumberattribute of theSegmentTemplateelement in the manifest. Default:0.chunk_duration_msโ duration of each chunk in milliseconds. This will go in thedurationattribute of theSegmentTemplateelement in the manifest. Default:1000.utc_timing_urlโ URL of the page that will return the UTC timestamp in ISO format. This will go in thevalueattribute of theUTCTimingelement in the manifest. Default: None.time_shift_buffer_depthโ smallest time (in seconds) shifting buffer for which any Representation is guaranteed to be available. This will go in thetimeShiftBufferDepthattribute of theMPDelement. Default:60.minimum_update_periodโ minimum update period (in seconds) of the manifest. This will go in theminimumUpdatePeriodattribute of theMPDelement. Default:0.
Example
ffmpeg -f webm_dash_manifest -i video1.webm \
-f webm_dash_manifest -i video2.webm \
-f webm_dash_manifest -i audio1.webm \
-f webm_dash_manifest -i audio2.webm \
-map 0 -map 1 -map 2 -map 3 \
-c copy \
-f webm_dash_manifest \
-adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
manifest.xml
โก whip
WebRTC (Real-Time Communication) muxer that supports sub-second latency streaming according to the WHIP (WebRTC-HTTP ingestion protocol) specification. Lowkey the coolest one here ngl ๐ธ.
โ ๏ธ Heads up bestie: this is an experimental feature. Not kidding around.
It uses HTTP as a signaling protocol to exchange SDP capabilities and ICE lite candidates. Then, it uses STUN binding requests and responses to establish a session over UDP. Subsequently, it initiates a DTLS handshake to exchange the SRTP encryption keys. Lastly, it splits video and audio frames into RTP packets and encrypts them using SRTP. Like, the whole pipeline, start to finish ๐ซ.
Ensure that you use H.264 without B frames and Opus for the audio codec. For example, to convert an input file with ffmpeg to WebRTC:
ffmpeg -re -i input.mp4 -acodec libopus -ar 48000 -ac 2 \
-vcodec libx264 -profile:v baseline -tune zerolatency -threads 1 -bf 0 \
-f whip "http://localhost:1985/rtc/v1/whip/?app=live&stream=livestream"
For this example, we have employed low latency options, resulting in an end-to-end latency of approximately 150ms. Ate, honestly ๐.
Options
This muxer supports the following options:
handshake_timeoutinteger โ set the timeout in milliseconds for ICE and DTLS handshake. Default value is5000.pkt_sizeinteger โ set the maximum size, in bytes, of RTP packets that send out. Default value is1200.ts_buffer_sizeinteger โ set the buffer size, in bytes, of underlying protocol. Default value is-1(auto). The UDP auto selects a reasonable value.whip_flagsflags โ possible values:dtls_activeโ the muxer will try to set dtls active role and send the first client hello.
rtp_historyinteger โ set the number of RTP history items to store. Default value is512.authorizationstring โ the optional Bearer token for WHIP Authorization ๐.cert_filestring โ the optional certificate file path for DTLS.key_filestring โ the optional private key file path for DTLS.
๐ต METADATA
FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded INI-like text file and then load it back using the metadata muxer/demuxer. It's giving notes-app-but-make-it-a-container-format ๐.
The file format is as follows:
- A file consists of a header and a number of metadata tags divided into sections, each on its own line.
- The header is a
;FFMETADATAstring, followed by a version number (now1). - Metadata tags are of the form
key=value - Immediately after header follows global metadata
- After global metadata there may be sections with per-stream/per-chapter metadata.
- A section starts with the section name in uppercase (i.e.
STREAMorCHAPTER) in brackets ([,]) and ends with next section or end of file. - At the beginning of a chapter section there may be an optional timebase to be used for start/end values. It must be in form
TIMEBASE=num/den, wherenumanddenare integers. If the timebase is missing then start/end times are assumed to be in nanoseconds.
Next a chapter section must contain chapter start and end times in form START=num, END=num, where num is a positive integer.
- Empty lines and lines starting with
;or#are ignored. - Metadata keys or values containing special characters (
=,;,#,\and a newline) must be escaped with a backslash\. - Note that whitespace in metadata (e.g.
foo = bar) is considered to be a part of the tag (in the example above key isfoo, value isbar). Yeah, the space is part of the vibe, don't @ me ๐.
A ffmetadata file might look like this:
;FFMETADATA1
title=bike\\shed
;this is a comment
artist=FFmpeg troll team
[CHAPTER]
TIMEBASE=1/1000
START=0
#chapter ends at 0:01:00
END=60000
title=chapter \#1
[STREAM]
title=multi\
line
By using the ffmetadata muxer and demuxer it is possible to extract metadata from an input file to an ffmetadata file, and then transcode the file into an output file with the edited ffmetadata file.
Extracting an ffmetadata file with ffmpeg goes as follows:
ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE
Reinserting edited metadata information from the FFMETADATAFILE file can be done as:
ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT
๐ PROTOCOL OPTIONS
The libavformat library provides some generic global options, which can be set on all the protocols. In addition each protocol may support so-called private options, which are specific for that component ๐.
Options may be set by specifying -option value in the FFmpeg tools, or by setting the value explicitly in the AVFormatContext options or using the libavutil/opt.h API for programmatic use.
The list of supported options follows:
protocol_whitelistlist (input) โ set a","-separated list of allowed protocols."ALL"matches all protocols. Protocols prefixed by-are disabled. All protocols are allowed by default but protocols used by an another protocol (nested protocols) are restricted to a per protocol subset ๐ซถ.
๐ PROTOCOLS
Protocols are configured elements in FFmpeg that enable access to resources that require specific protocols.
When you configure your FFmpeg build, all the supported protocols are enabled by default. You can list all available ones using the configure option --list-protocols โจ.
okay so bestie, you can disable all the protocols with the configure option --disable-protocols, and then selectively enable one with --enable-protocol=PROTOCOL, or you can disable one particular protocol with --disable-protocol=PROTOCOL. โจ
The -protocols option of the ff* tools will display the list of supported protocols. ๐
All protocols accept the following option:
rw_timeoutโ maximum time to wait for (network) read/write operations to complete, in microseconds. โฑ๏ธ
A description of the currently available protocols follows โ letโs go ๐ซถ
๐ amqp
Advanced Message Queueing Protocol (AMQP) version 0-9-1 is a broker based publish-subscribe communication protocol. iconic little message-broker behavior ๐
FFmpeg must be compiled with --enable-librabbitmq to support AMQP. A separate AMQP broker must also be run. An example open-source AMQP broker is RabbitMQ. ๐ฐ
After starting the broker, an FFmpeg client may stream data to the broker using the command:
ffmpeg -re -i input -f mpegts amqp://[[user]:[password]@]hostname[:port][/vhost]
Where hostname and port (default is 5672) is the address of the broker. The client may also set a user/password for authentication. The default for both fields is "guest". Name of virtual host on broker can be set with vhost. The default value is "/". ๐ธ
Multiple subscribers may stream from the broker using the command:
ffplay amqp://[[user]:[password]@]hostname[:port][/vhost]
In RabbitMQ all data published to the broker flows through a specific exchange, and each subscribing client has an assigned queue/buffer. When a packet arrives at an exchange, it may be copied to a clientโs queue depending on the exchange and routing_key fields. ๐
The following options are supported:
exchangeโ sets the exchange to use on the broker. RabbitMQ has several predefined exchanges:"amq.direct"is the default exchange, where the publisher and subscriber must have a matchingrouting_key;"amq.fanout"is the same as a broadcast operation (i.e. the data is forwarded to all queues on the fanout exchange independent of therouting_key); and"amq.topic"is similar to"amq.direct", but allows for more complex pattern matching (refer to the RabbitMQ documentation). ๐ซrouting_keyโ sets the routing key. The default value is"amqp". The routing key is used on the"amq.direct"and"amq.topic"exchanges to decide whether packets are written to the queue of a subscriber. ๐pkt_sizeโ maximum size of each packet sent/received to the broker. Default is131072. Minimum is4096and max is any large value (representable by anint). When receiving packets, this sets an internal buffer size in FFmpeg. It should be equal to or greater than the size of the published packets to the broker. Otherwise the received message may be truncated causing decoding errors. ๐ญconnection_timeoutโ the timeout in seconds during the initial connection to the broker. The default value isrw_timeout, or5seconds ifrw_timeoutis not set. โณdelivery_mode modeโ sets the delivery mode of each message sent to broker. The following values are accepted:persistentโ delivery mode set to"persistent"(2). This is the default value. Messages may be written to the brokerโs disk depending on its setup. ๐พnon-persistentโ delivery mode set to"non-persistent"(1). Messages will stay in brokerโs memory unless the broker is under memory pressure. ๐ง
๐ฆ async
Asynchronous data filling wrapper for input stream. ๐
Fill data in a background thread, to decouple I/O operation from demux thread. multitasking queen behavior ๐
async:<URL>
async:http://host/resource
async:cache:http://host/resource
๐ฟ bluray
Read BluRay playlist. ๐
The accepted options are:
angleโ BluRay angle ๐ฌchapterโ start chapter (1...N) ๐playlistโ playlist to read (BDMV/PLAYLIST/?????.mpls) ๐๏ธ
Examples:
Read longest playlist from BluRay mounted to /mnt/bluray:
bluray:/mnt/bluray
Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:
-playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray
๐งบ cache
Caching wrapper for input stream. ๐
Cache the input stream to temporary file. It brings seeking capability to live streams. lowkey magical โจ
The accepted options are:
read_ahead_limitโ amount in bytes that may be read ahead when seeking isnโt supported. Range is-1toINT_MAX.-1for unlimited. Default is65536. ๐
URL Syntax is
cache:<URL>
๐ concat
Physical concatenation protocol. ๐งต
Read and seek from many resources in sequence as if they were a unique resource. one big happy file ๐
A URL accepted by this protocol has the syntax:
concat:<URL1>|<URL2>|...|<URLN>
where URL1, URL2, ..., URLN are the urls of the resource to be concatenated, each one possibly specifying a distinct protocol. ๐
For example to read a sequence of files split1.mpeg, split2.mpeg, split3.mpeg with ffplay use the command:
ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
Note that you may need to escape the character "|" which is special for many shells. ๐ญ๐
๐ concatf
Physical concatenation protocol using a line break delimited list of resources. ๐๏ธ
Read and seek from many resources in sequence as if they were a unique resource. ๐ซถ
A URL accepted by this protocol has the syntax:
concatf:<URL>
where URL is the url containing a line break delimited list of resources to be concatenated, each one possibly specifying a distinct protocol. Special characters must be escaped with backslash or single quotes. See the "Quoting and escaping" section in the ffmpeg-utils(1) manual. ๐ง
For example to read a sequence of files split1.mpeg, split2.mpeg, split3.mpeg listed in separate lines within a file split.txt with ffplay use the command:
ffplay concatf:split.txt
Where split.txt contains the lines:
split1.mpeg
split2.mpeg
split3.mpeg
๐ crypto
AES-encrypted stream reading protocol. ๐ต๏ธโโ๏ธ
The accepted options are:
keyโ set the AES decryption key binary block from given hexadecimal representation. ๐ivโ set the AES decryption initialization vector binary block from given hexadecimal representation. ๐งฌ
Accepted URL formats:
crypto:<URL>
crypto+<URL>
๐ง data
Data in-line in the URI. See http://en.wikipedia.org/wiki/Data_URI_scheme. ๐
For example, to convert a GIF file given inline with ffmpeg:
ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
๐ช fd
File descriptor access protocol. ๐
The accepted syntax is:
fd: -fd <file_descriptor>
If fd is not specified, by default the stdout file descriptor will be used for writing, stdin for reading. Unlike the pipe protocol, fd protocol has seek support if it corresponding to a regular file. fd protocol doesnโt support pass file descriptor via URL for security. ๐
This protocol accepts the following options:
blocksizeโ set I/O operation maximum block size, in bytes. Default value is"INT_MAX", which results in not limiting the requested block size. Setting this value reasonably low improves user termination request reaction time, which is valuable if data transmission is slow. ๐งฑfdโ set file descriptor. ๐ชช
๐ file
File access protocol. ๐
Read from or write to a file. ๐๏ธ
A file URL can have the form:
file:<filename>
where filename is the path of the file to read. ๐ธ
An URL that does not have a protocol prefix will be assumed to be a file URL. Depending on the build, an URL that looks like a Windows path with the drive letter at the beginning will also be assumed to be a file URL (usually not the case in builds for unix-like systems). ๐ช
For example to read from a file input.mpeg with ffmpeg use the command:
ffmpeg -i file:input.mpeg output.mpeg
This protocol accepts the following options:
truncateโ truncate existing files on write, if set to1. A value of0prevents truncating. Default value is1. โ๏ธblocksizeโ set I/O operation maximum block size, in bytes. Default value is"INT_MAX", which results in not limiting the requested block size. Setting this value reasonably low improves user termination request reaction time, which is valuable for files on slow medium. ๐ขfollowโ if set to1, the protocol will retry reading at the end of the file, allowing reading files that still are being written. In order for this to terminate, you either need to use therw_timeoutoption, or use the interrupt callback (for API users). ๐seekableโ controls if seekability is advertised on the file.0means non-seekable,-1means auto (seekable for normal files, non-seekable for named pipes). Many demuxers handle seekable and non-seekable resources differently, overriding this might speed up opening certain files at the cost of losing some features (e.g. accurate seeking). ๐งญpkt_sizeโ set the maximum packet size used for file I/O. A smaller value may reduce memory usage. A higher value may increase throughput especially with networked filesystems. For reading, if explicitly set, it overrides the default internal buffer size (32 KB) and limits the maximum amount of data read per operation. For writing, this sets the size of each write operation. The default is256 KBfor regular files,32 KBotherwise. ๐ฆ
๐ ftp
FTP (File Transfer Protocol). ๐ก
Read from or write to remote resources using FTP protocol. ๐ซถ
Following syntax is required.
ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
This protocol accepts the following options. ๐
timeoutโ set timeout in microseconds of socket I/O operations used by the underlying low level operation. By default it is set to-1, which means that the timeout is not specified. โฑ๏ธftp-userโ set a user to be used for authenticating to the FTP server. This is overridden by the user in the FTP URL. ๐คftp-passwordโ set a password to be used for authenticating to the FTP server. This is overridden by the password in the FTP URL, or byftp-anonymous-passwordif no user is set. ๐ftp-anonymous-passwordโ password used when login as anonymous user. Typically an e-mail address should be used. ๐งftp-write-seekableโ control seekability of connection during encoding. If set to1the resource is supposed to be seekable, if set to0it is assumed not to be seekable. Default value is0. ๐ฏ
๐ซถ NOTE: Protocol can be used as output, but it is recommended to not do it, unless special care is taken (tests, customized server configuration etc.). Different FTP servers behave in different way during seek operation. ff* tools may produce incomplete content due to server limitations.
gopher ๐ฆ
Gopher protocol. That's it, that's the whole vibe. Old school but still iconic.
gophers โจ
Gophers protocol โ literally gopher but with a glow-up.
The Gopher protocol with TLS encapsulation. Secure vibes only ๐
http ๐
HTTP (Hyper Text Transfer Protocol). The main character of protocols, no cap.
This protocol accepts the following options:
seekableโ Controls whether the connection can seek. Set it to1and the resource is supposed to be seekable, set it to0and it's assumed not seekable, and set it to-1and it'll try to autodetect seekability for you. Default value is-1.chunked_postโ If set to1use chunked Transfer-Encoding for posts. Default is1.http_proxyโ Sets the HTTP proxy to tunnel through, like e.g.http://example.com:1234.headersโ Set custom HTTP headers โ you can override the built-in default headers with this. The value must be a string encoding the headers.content_typeโ Set a specific content type for the POST messages, or for listen mode.user_agentโ Override the User-Agent header. If you don't specify one, the protocol will use a string describing the libavformat build. ("Lavf/<version>")refererโ Sets the Referer header. Includes the'Referer: URL'header in the HTTP request.multiple_requestsโ Use persistent connections if set to1. Default is0.request_sizeโ Limits the size of requests made. This is useful for some pathological servers that throttle unbounded range requests, and also when you're expecting to seek frequently. Disabled (set to0) by default.
Note that if you enable this option, it's strongly recommended to also enable the multiple_requests option, as well as setting short_seek_size to the same value or higher. Doing so lets FFmpeg reuse a single HTTP connection wherever possible. Recycle, bestie โป๏ธ
initial_request_sizeโ Limits the size of initial requests. Similar torequest_size, but only used during initial format parsing. Useful for formats like MXF or MOV that require frequent seeks during header parsing. It lasts until the demuxer makes a read request larger than this size (without a seek in between), after which the implementation will carry on using requests as usual. Disabled (set to0) by default.
Note that if you enable this option, it's strongly recommended to also enable the multiple_requests option, as well as setting short_seek_size to the same value or higher.
post_dataโ Set custom HTTP post data.mime_typeโ Exports the MIME type.http_versionโ Exports the HTTP response version number. Usually"1.0"or"1.1".cookiesโ Sets the cookies to be sent in future requests. The format of each cookie is the same as the value of aSet-CookieHTTP response field. Multiple cookies can be delimited by a newline character.icyโ If set to1request ICY (SHOUTcast) metadata from the server. If the server supports this, the metadata has to be retrieved by the application by reading theicy_metadata_headersandicy_metadata_packetoptions. The default is1.icy_metadata_headersโ If the server supports ICY metadata, this contains the ICY-specific HTTP reply headers, separated by newline characters.icy_metadata_packetโ If the server supports ICY metadata, andicywas set to1, this contains the last non-empty metadata packet sent by the server. Applications interested in mid-stream metadata updates should poll it at regular intervals.metadataโ Set an exported dictionary containing Icecast metadata from the bitstream, if present. Only useful with the C API.auth_typeโ Set the HTTP authentication type. There's no option for Digest, because that method requires getting nonce parameters from the server first and can't be used straight away like Basic.noneโ Choose the HTTP authentication type automatically. This is the default.basicโ Choose HTTP basic authentication.
โ ๏ธ Okay so listen up because this one matters: Basic authentication sends a Base64-encoded string that contains a user name and password for the client. Base64 is not a form of encryption and should be considered the same as sending the user name and password in clear text (Base64 is a reversible encoding). If a resource needs to be protected, strongly consider using an authentication scheme other than basic authentication. HTTPS/TLS should be used with basic authentication. Without these additional security enhancements, basic authentication should not be used to protect sensitive or valuable information. Not me warning you twice ๐
send_expect_100โ Sends anExpect: 100-continueheader for POST. If set to1it will send, if set to0it won't, and if set to-1it'll try to send if it's applicable. Default value is-1.locationโ An exported dictionary containing the content location. Only useful with the C API.offsetโ Set initial byte offset.end_offsetโ Try to limit the request to bytes preceding this offset.methodโ When used as a client option it sets the HTTP method for the request.
When used as a server option it sets the HTTP method that is going to be expected from the client(s). If the expected and the received HTTP method don't match, the client will be given a Bad Request response. When unset, the HTTP method is not checked for now. This will be replaced by autodetection in the future.
reconnectโ Reconnect automatically when disconnected before EOF is hit.reconnect_at_eofโ If set then eof is treated like an error and causes reconnection. This is useful for live / endless streams.reconnect_on_network_errorโ Reconnect automatically in case of TCP/TLS errors during connect.reconnect_on_http_errorโ A comma separated list of HTTP status codes to reconnect on. The list can include specific status codes (e.g.'503') or the strings'4xx'/'5xx'.reconnect_streamedโ If set then even streamed/non seekable streams will be reconnected on errors.reconnect_delay_maxโ Set the maximum delay in seconds after which to give up reconnecting.reconnect_max_retriesโ Set the maximum number of times to retry a connection. Default unset.reconnect_delay_total_maxโ Set the maximum total delay in seconds after which to give up reconnecting.respect_retry_afterโ If enabled, and aRetry-Afterheader is encountered, its requested reconnection delay will be honored, rather than using exponential backoff. Useful for429and503errors. Default enabled.listenโ If set to1enables experimental HTTP server. This can be used to send data when used as an output option, or read data from a client with HTTP POST when used as an input option. If set to2enables experimental multi-client HTTP server. This is not yet implemented inffmpeg.cand thus must not be used as a command line option.
# Server side (sending):
ffmpeg -i somefile.ogg -c copy -listen 1 -f ogg http://<server>:<port>
# Client side (receiving):
ffmpeg -i http://<server>:<port> -c copy somefile.ogg
# Client can also be done with wget:
wget http://<server>:<port> -O somefile.ogg
# Server side (receiving):
ffmpeg -listen 1 -i http://<server>:<port> -c copy somefile.ogg
# Client side (sending):
ffmpeg -i somefile.ogg -chunked_post 0 -c copy -f ogg http://<server>:<port>
# Client can also be done with wget:
wget --post-file=somefile.ogg http://<server>:<port>
resourceโ The resource requested by a client, when the experimental HTTP server is in use.reply_codeโ The HTTP code returned to the client, when the experimental HTTP server is in use.short_seek_sizeโ Set the threshold, in bytes, for when a readahead should be preferred over a seek and new HTTP request. This is useful, for example, to make sure the same connection is used for reading large video packets with small audio packets in between ๐
HTTP Cookies ๐ช
Some HTTP requests will be denied unless cookie values are passed in with the request. The cookies option lets you specify these cookies. At the very least, each cookie must specify a value along with a path and domain. HTTP requests that match both the domain and path will automatically include the cookie value in the HTTP Cookie header field. Multiple cookies can be delimited by a newline.
The required syntax to play a stream specifying a cookie is:
ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8
Icecast ๐
Icecast protocol (stream to Icecast servers). Radio-host era, we love to see it โจ
This protocol accepts the following options:
ice_genreโ Set the stream genre.ice_nameโ Set the stream name.ice_descriptionโ Set the stream description.ice_urlโ Set the stream website URL.ice_publicโ Set if the stream should be public. The default is0(not public).user_agentโ Override the User-Agent header. If not specified a string of the form"Lavf/<version>"will be used.passwordโ Set the Icecast mountpoint password.content_typeโ Set the stream content type. This must be set if it is different fromaudio/mpeg.legacy_icecastโ This enables support for Icecast versions< 2.4.0, that do not support the HTTPPUTmethod but theSOURCEmethod.tlsโ Establish a TLS (HTTPS) connection to Icecast.
icecast://[<username>[:<password>]@]<server>:<port>/<mountpoint>
ipfs ๐ง
InterPlanetary File System (IPFS) protocol support. You can access files stored on the IPFS network through so-called gateways. These are http(s) endpoints. This protocol wraps the IPFS native protocols (ipfs:// and ipns://) to be sent to such a gateway. Users can (and should) host their own node, which means this protocol will use your local gateway to access files on the IPFS network.
This protocol accepts the following options:
gatewayโ Defines the gateway to use. When not set, the protocol will first try locating the local gateway by looking at$IPFS_GATEWAY,$IPFS_PATHand"$HOME/.ipfs/", in that order.
You can use this protocol in 2 ways. Using IPFS:
ffplay ipfs://<hash>
Or the IPNS protocol (IPNS is mutable IPFS):
ffplay ipns://<hash>
okay that's the ipns moment wrapped, moving on bestie ๐
mmst ๐ช
MMS (Microsoft Media Server) protocol, riding on top of TCP. that's it, that's the whole vibe.
mmsh ๐ชโจ
Same MMS energy but over HTTP instead. The required syntax is, and I quote:
mmsh://<server>[:<port>][/<app>][/<playpath>]
md5 ๐งฎ๐
The MD5 output protocol. It computes the MD5 hash of the data that's being written, and then on close it writes that hash to the designated output โ or to stdout if you didn't specify one. It's literally the move for testing muxers without committing to writing an actual file. iconique for debugging, no cap.
Some examples, because bestie loves an example:
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
ffmpeg -i input.flv -f avi -y md5:output.avi.md5
# Write the MD5 hash of the encoded AVI file to stdout.
ffmpeg -i input.flv -f avi -y md5:
โ ๏ธ heads up: some formats (typically MOV) require the output protocol to be seekable, so they will fail with the MD5 output protocol. not a vibe, but it is the rules ๐ญ
pipe ๐ฐ๐ซถ
The UNIX pipe access protocol. Read and write from UNIX pipes, that's the whole job.
The accepted syntax is:
pipe:[<number>]
If fd isn't specified, number is the number corresponding to the file descriptor of the pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). And if number isn't specified at all, then by default the stdout file descriptor gets used for writing, and stdin for reading. slay, sensible defaults ๐
So like, to read from stdin with ffmpeg:
cat test.wav | ffmpeg -i pipe:0
# ...this is the same as...
cat test.wav | ffmpeg -i pipe:
And to write to stdout with ffmpeg:
ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
# ...this is the same as...
ffmpeg -i test.wav -f avi pipe: | cat > test.avi
This protocol accepts the following options:
blocksizeโ sets the I/O operation maximum block size, in bytes. Default value isINT_MAX, which results in not limiting the requested block size at all. Setting this value reasonably low improves your user-termination-request reaction time, which is genuinely valuable if the data transmission is slow. lowkey a glow-up for responsiveness โจfdโ set file descriptor.
โ ๏ธ and again, the classic: some formats (typically MOV) require the output protocol to be seekable, so they will fail with the pipe output protocol. ๐ญ
prompeg ๐ก๐ฅ
The Pro-MPEG Code of Practice #3 Release 2 FEC protocol.
So the Pro-MPEG CoP#3 FEC is a 2D parity-check forward error correction mechanism for MPEG-2 Transport Streams sent over RTP. very "main character of error correction" if you ask me.
This protocol must be used in conjunction with the rtp_mpegts muxer and the rtp protocol. they're a package deal, iykyk.
The required syntax is:
-f rtp_mpegts -fec prompeg=<option>=<val>... rtp://<hostname>:<port>
The destination UDP ports are port + 2 for the column FEC stream and port + 4 for the row FEC stream.
This protocol accepts the following options:
l=nโ the number of columns (4-20,LxD <= 100)d=nโ the number of rows (4-20,LxD <= 100)
Example usage:
-f rtp_mpegts -fec prompeg=l=8:d=4 rtp://<hostname>:<port>
rist ๐๐
Reliable Internet Streaming Transport protocol. The accepted options are:
rist_profileโ supported values:simplemainโ this one is default.advanced
buffer_sizeโ set the internal RIST buffer size in milliseconds for retransmission of data. Default value is0, which means the librist default (1 sec). Maximum value is30 seconds.fifo_sizeโ size of the librist receiver output fifo in number of packets. This must be a power of 2. Defaults to8192(vs the librist default of1024).overrun_nonfatal=1|0โ survive in case of librist fifo buffer overrun. Default value is0.pkt_sizeโ set maximum packet size for sending data.1316by default.log_levelโ set loglevel for RIST logging messages. You only need to set this if you explicitly want to enable debug level messages or packet loss simulation, otherwise the regular loglevel is respected.secretโ set override of encryption secret, by default is unset.encryptionโ set encryption type, by default is disabled. Acceptable values are128and256.
rtmp ๐๐บ
Real-Time Messaging Protocol. The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia content across a TCP/IP network. the blueprint, fr fr.
The required syntax is:
rtmp://[<username>:<password>@]<server>[:<port>][/<app>][/<instance>][/<playpath>]
The accepted parameters are:
usernameโ an optional username (mostly for publishing).passwordโ an optional password (mostly for publishing).serverโ the address of the RTMP server.portโ the number of the TCP port to use (by default is1935).appโ it is the name of the application to access. It usually corresponds to the path where the application is installed on the RTMP server (e.g./ondemand/,/flash/live/, etc.). You can override the value parsed from the URI through thertmp_appoption, too.playpathโ it is the path or name of the resource to play with reference to the application specified in app, may be prefixed bymp4:. You can override the value parsed from the URI through thertmp_playpathoption, too.listenโ act as a server, listening for an incoming connection.timeoutโ maximum time to wait for the incoming connection. Implieslisten.
Additionally, the following parameters can be set via command line options (or in code via AVOptions):
rtmp_appโ name of application to connect on the RTMP server. This option overrides the parameter specified in the URI.rtmp_bufferโ set the client buffer time in milliseconds. The default is3000.rtmp_connโ extra arbitrary AMF connection parameters, parsed from a string, e.g. likeB:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0. Each value is prefixed by a single character denoting the type:Bfor Boolean,Nfor number,Sfor string,Ofor object, orZfor null, followed by a colon. For Booleans the data must be either0or1for FALSE or TRUE, respectively. Likewise for Objects the data must be0or1to end or begin an object, respectively. Data items in subobjects may be named, by prefixing the type withNand specifying the name before the value (i.e.NB:myFlag:1). This option may be used multiple times to construct arbitrary AMF sequences. very build-your-own-adventure of it ๐rtmp_enhanced_codecsโ specify the list of codecs the client advertises to support in an enhanced RTMP stream. This option should be set to a comma separated list of fourcc values, likehvc1,av01,vp09for multiple codecs orhvc1for only one codec. The specified list will be presented in thefourCcLiveproperty of the Connect Command Message.rtmp_flashverโ version of the Flash plugin used to run the SWF player. The default isLNX 9,0,124,2. (When publishing, the default isFMLE/3.0 (compatible; <libavformat version>).) yeah we're still honoring the Flash lore in this economy ๐rtmp_flush_intervalโ number of packets flushed in the same request (RTMPT only). The default is10.rtmp_liveโ specify that the media is a live stream. No resuming or seeking in live streams is possible. The default value isany, which means the subscriber first tries to play the live stream specified in the playpath. If a live stream of that name is not found, it plays the recorded stream. The other possible values areliveandrecorded.rtmp_pageurlโ URL of the web page in which the media was embedded. By default no value will be sent.rtmp_playpathโ stream identifier to play or to publish. This option overrides the parameter specified in the URI.rtmp_subscribeโ name of live stream to subscribe to. By default no value will be sent. It is only sent if the option is specified or ifrtmp_liveis set tolive.rtmp_swfhashโ SHA256 hash of the decompressed SWF file (32bytes).rtmp_swfsizeโ size of the decompressed SWF file, required for SWFVerification.rtmp_swfurlโ URL of the SWF player for the media. By default no value will be sent.rtmp_swfverifyโ URL to player swf file, compute hash/size automatically.rtmp_tcurlโ URL of the target stream. Defaults toproto://host[:port]/app.tcp_nodelay=1|0โ setTCP_NODELAYto disable Nagle's algorithm. Default value is0.
remark: writing to the socket is currently not optimized to minimize system calls and reduces the efficiency / effect of TCP_NODELAY. so like, don't expect miracles ๐
tcp_keepalive=1|0โ enable the TCP keepalive mechanism to detect dead peers and help maintain long-lived idle connections. Default value is0.
Only the basic keepalive option (SO_KEEPALIVE) can be enabled or disabled. Platform-specific tuning parameters such asTCP_KEEPIDLE,TCP_KEEPINTVL, orTCP_KEEPCNTare not configurable and will use the operating system's default values.
For example to read with ffplay a multimedia resource named "sample" from the application "vod" from an RTMP server "myserver":
ffplay rtmp://myserver/vod/sample
To publish to a password protected server, passing the playpath and app names separately:
ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/
rtmpe ๐
Encrypted Real-Time Messaging Protocol. RTMPE is used for streaming multimedia content within standard cryptographic primitives, consisting of Diffie-Hellman key exchange and HMACSHA256, generating a pair of RC4 keys. look at her go with the cryptography ๐ โจ
rtmps ๐ก๏ธ
Real-Time Messaging Protocol over a secure SSL connection. RTMPS is used for streaming multimedia content across an encrypted connection. the laced-up version, we love her.
rtmpt ๐
Real-Time Messaging Protocol tunneled through HTTP. RTMPT is used for streaming multimedia content within HTTP requests to traverse firewalls. sneaky lil thing, slipping past the firewall ๐ญ
rtmpte ๐๐
Encrypted Real-Time Messaging Protocol tunneled through HTTP. RTMPTE is used for streaming multimedia content within HTTP requests to traverse firewalls. firewall-avoidance AND encryption? she's doing both.
rtmpts ๐๐ก๏ธ
Real-Time Messaging Protocol tunneled through HTTPS. RTMPTS is used for streaming multimedia content within HTTPS requests to traverse firewalls. the final boss of the rtmp cinematic universe.
libsmbclient ๐๏ธ๐ธ
libsmbclient permits one to manipulate CIFS/SMB network resources โ network shares, bestie. Following syntax is required:
smb://[[domain:]user[:password@]]server[/share[/path[/file]]]
This protocol accepts the following options.
timeoutโ sets the timeout, in milliseconds, for the socket I/O ops that the underlying low-level stuff does. Default is-1, which literally means "no timeout specified, we're just vibing" โจtruncateโ truncates existing files on write if you set it to1. Set it to0and no truncating happens, no cap. Default is1.workgroupโ sets the workgroup used for making connections. By default the workgroup is not specified ๐ซถ
For more info, the original points you at http://www.samba.org/ ๐
๐ง libssh
Secure File Transfer Protocol via libssh โ yes bestie, that's SFTP ๐ฆ
Read from or write to remote resources using the SFTP protocol.
The following syntax is required, no exceptions:
sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
This protocol accepts the following options:
timeoutโ sets the timeout of socket I/O operations used by the underlying low-level operation. By default it's-1, meaning the timeout is not specified ๐truncateโ truncates existing files on write if set to1; a value of0prevents truncating. Default value is1.private_keyโ specify the path of the file containing the private key to use during authorization. By default libssh searches for keys in the~/.ssh/directory ๐
Example: play a file stored on a remote server ๐
ffplay sftp://user:password@server_address:22/home/user/resource.mpeg
๐ librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte
Real-Time Messaging Protocol and its variants, supported through librtmp. It's giving legacy but iconic ๐
Requires the presence of the librtmp headers and library during configuration. You need to explicitly configure the build with --enable-librtmp. If enabled, this will replace the native RTMP protocol โ like, swap it out entirely, heads up.
This protocol provides most client functions and a few server functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT), encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS), and tunneled variants of these encrypted types (RTMPTE, RTMPTS). So many letters, but they all slay in their own way ๐
The required syntax is:
<rtmp_proto>://<server>[:<port>][/<app>][/<playpath>] <options>
where rtmp_proto is one of the strings rtmp, rtmpt, rtmpe, rtmps, rtmpte, rtmpts, corresponding to each RTMP variant ๐ฆ and server, port, app and playpath have the same meaning as specified for the RTMP native protocol. options contains a list of space-separated options of the form key=val.
See the librtmp manual page (man 3 librtmp) for more information.
For example, to stream a file in real-time to an RTMP server using ffmpeg:
ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
To play the same stream using ffplay:
ffplay "rtmp://myserver/live/mystream live=1"
๐ rtp
Real-time Transport Protocol. Main character of streaming, honestly โจ
The required syntax for an RTP URL is:
rtp://<hostname>[:<port>][?<options>]
port specifies the RTP port to use.
options contains a list of &-separated options of the form key=val. Standard percent-encoding (and using the plus sign for space) can be used to escape keys and values ๐ซถ
Options can also be specified via command line options (or in code via AVOptions).
The list of supported options follows, and yes, we're going through all of them ๐
ttl=nโ sets the TTL (Time-To-Live) value (for multicast only).rtcpport=nโ sets the remote RTCP port to n.localport,local_rtpport,localrtpport=nโ sets the local RTP port to n.
Using the localport option name is deprecated and should not be used. Like, don't. ๐
local_rtcpport,localrtcpport=n'โ sets the local RTCP port to n.pkt_size=nโ sets max packet size (in bytes) to n.buffer_size=sizeโ sets the maximum UDP socket buffer size in bytes.connect=0|1โ does aconnect()on the UDP socket (if set to1) or not (if set to0).sources=ip[,ip]โ lists allowed source IP addresses.block=ip[,ip]โ lists disallowed (blocked) source IP addresses. Blocked blocked ๐write_to_source=0|1โ sends packets to the source address of the latest received packet (if set to1) or to a default remote address (if set to0).localaddr=addrโ local IP address of a network interface used for sending packets or joining multicast groups.timeout=nโ sets timeout (in microseconds) of socket I/O operations to n. Microseconds bestie, read it again ๐ญ
Important notes:
- If
rtcpportis not set, the RTCP port will be set to the RTP port value plus1. - If
localrtpport(the local RTP port) is not set, any available port will be used for the local RTP and RTCP ports. - If
localrtcpport(the local RTCP port) is not set, it will be set to the local RTP port value plus1.
๐ธ rtsp
Real-Time Streaming Protocol.
RTSP is not technically a protocol handler in libavformat โ plot twist โ it's a demuxer and muxer. The demuxer supports both normal RTSP (with data transferred over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with data transferred over RDT) ๐
The muxer can be used to send a stream using RTSP ANNOUNCE to a server supporting it (currently Darwin Streaming Server and Mischa Spiegelmock's https://github.com/revmischa/rtsp-server).
The required syntax for an RTSP url is:
rtsp://<hostname>[:<port>]/<path>
Options can be set on the ffmpeg/ffplay command line, or set in code via AVOptions or in avformat_open_input.
Muxer
The following options are supported ๐
rtsp_transportโ sets RTSP transport protocols.
It accepts the following values:
udpโ use UDP as lower transport protocol.tcpโ use TCP (interleaving within the RTSP control channel) as lower transport protocol.
Default value is 0.
rtsp_flagsโ sets RTSP flags.
The following values are accepted:
latmโ use MP4A-LATM packetization instead of MPEG4-GENERIC for AAC.rfc2190โ use RFC 2190 packetization instead of RFC 4629 for H.263.skip_rtcpโ don't send RTCP sender reports.h264_mode0โ use mode 0 for H.264 in RTP.send_byeโ send RTCP BYE packets when finishing.
Default value is 0.
min_portโ sets minimum local UDP port. Default value is5000.max_portโ sets maximum local UDP port. Default value is65000.buffer_sizeโ sets the maximum socket buffer size in bytes.pkt_sizeโ sets max send packet size (in bytes). Default value is1472.
Demuxer
The following options are supported โจ
initial_pauseโ do not start playing the stream immediately if set to1. Default value is0.rtsp_transportโ sets RTSP transport protocols.
It accepts the following values:
udpโ use UDP as lower transport protocol.tcpโ use TCP (interleaving within the RTSP control channel) as lower transport protocol.udp_multicastโ use UDP multicast as lower transport protocol.httpโ use HTTP tunneling as lower transport protocol, which is useful for passing proxies.httpsโ use HTTPs tunneling as lower transport protocol, which is useful for passing proxies and widely used for security consideration.
Multiple lower transport protocols may be specified, in that case they are tried one at a time (if the setup of one fails, the next one is tried). For the muxer, only the tcp and udp options are supported.
rtsp_flagsโ sets RTSP flags.
The following values are accepted:
filter_srcโ accept packets only from negotiated peer address and port.listenโ act as a server, listening for an incoming connection.prefer_tcpโ try TCP for RTP transport first, if TCP is available as RTSP RTP transport.satip_rawโ export raw MPEG-TS stream instead of demuxing. The flag will simply write out the raw stream, with the original PAT/PMT/PIDs intact.
Default value is none.
allowed_media_typesโ sets media types to accept from the server.
The following flags are accepted:
videoaudiodatasubtitle
By default it accepts all media types.
min_portโ sets minimum local UDP port. Default value is5000.max_portโ sets maximum local UDP port. Default value is65000.listen_timeoutโ sets maximum timeout (in seconds) to establish an initial connection. Settinglisten_timeout>0setsrtsp_flagstolisten. Default is-1, which means an infinite timeout when listen mode is set ๐ซถreorder_queue_sizeโ sets number of packets to buffer for handling of reordered packets.timeoutโ sets socket TCP I/O timeout in microseconds.user_agentโ overrides the User-Agent header. If not specified, it defaults to the libavformat identifier string.buffer_sizeโ sets the maximum socket buffer size in bytes.
When receiving data over UDP, the demuxer tries to reorder received packets (since they may arrive out of order, or packets may get lost totally ๐ญ). This can be disabled by setting the maximum demuxing delay to zero (via the max_delay field of AVFormatContext).
When watching multi-bitrate Real-RTSP streams with ffplay, the streams to display can be chosen with -vst n and -ast n for video and audio respectively, and can be switched on the fly by pressing v and a ๐
Examples
The following examples all make use of the ffplay and ffmpeg tools.
- Watch a stream over UDP, with a max reordering delay of 0.5 seconds:
ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
- Watch a stream tunneled over HTTP:
ffplay -rtsp_transport http rtsp://server/video.mp4
- Send a stream in realtime to a RTSP server, for others to watch:
ffmpeg -re -i <input> -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
- Receive a stream in realtime:
ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp <output>
๐ฆ sap
Session Announcement Protocol (RFC 2974). This is not technically a protocol handler in libavformat โ again, it's a muxer and demuxer. It's used for signalling of RTP streams, by announcing the SDP for the streams regularly on a separate port ๐
Muxer
The syntax for a SAP url given to the muxer is:
sap://<destination>[:<port>][?<options>]
The RTP packets are sent to destination on port port, or to port 5004 if no port is specified. options is a &-separated list. The following options are supported:
announce_addr=addressโ specify the destination IP address for sending the announcements to. If omitted, the announcements are sent to the commonly used SAP announcement multicast address224.2.127.254(sap.mcast.net), orff0e::2:7ffeif destination is an IPv6 address ๐announce_port=portโ which port the announcements go out on ๐ if you don't say anything it defaults to9875(no cap, it's just the vibe).ttl=ttlโ the time to live value for the announcements and the RTP packets, defaults to255โจ.same_port=0|1โ set this to1and literally all RTP streams get sent on the same port pair. set it to zero (that's the default bestie) and every stream goes out on its own unique port, each one sitting 2 numbers higher than the previous one. ๐ heads up: VLC/Live555 requires this to be1to actually receive the stream, and the RTP stack in libavformat for receiving requires all streams to be sent on unique ports. so like, pick your fighter ๐ญ.
Example command lines follow ๐ซถ
to broadcast a stream on the local subnet, for watching in VLC:
ffmpeg -re -i <input> -f sap sap://224.0.0.255?same_port=1
similarly, for watching in ffplay:
ffmpeg -re -i <input> -f sap sap://224.0.0.255
and for watching in ffplay, over IPv6:
ffmpeg -re -i <input> -f sap sap://[ff0e::1:2:3:4]
โจ Demuxer โจ
the syntax for a SAP url handed to the demuxer is:
sap://[<address>][:<port>]
address is the multicast address to listen for announcements on โ if you omit it, the default 224.2.127.254 (sap.mcast.net) is used ๐. port is the port that's listened on, 9875 if omitted.
the demuxer listens for announcements on the given address and port. once an announcement shows up, it tries to receive that particular stream ๐ฆ.
Example command lines follow ๐ธ
to play back the first stream announced on the normal SAP multicast address:
ffplay sap://
to play back the first stream announced on one the default IPv6 SAP multicast address:
ffplay sap://[ff0e::2:7ffe]
๐ sctp ๐
Stream Control Transmission Protocol. iconic transport-layer behavior honestly ๐
the accepted URL syntax is:
sctp://<host>:<port>[?<options>]
options contains a list of &-separated options of the form key=val. standard percent-encoding (and using the plus sign for space) can be used to escape keys and values ๐.
options can also can be specified via command line options (or in code via AVOptions).
the list of supported options follows โญ
listenโ if set to any value, listen for an incoming connection. outgoing connection is done by default.max_streamsโ set the maximum number of streams. by default no limit is set ๐.
๐ง srt ๐ง
Haivision Secure Reliable Transport Protocol via libsrt ๐ฅ.
the supported syntax for a SRT URL is:
srt://<hostname>:<port>[?<options>]
options contains a list of &-separated options of the form key=val. standard percent-encoding (and using the plus sign for space) can be used to escape keys and values ๐.
options can also can be specified via command line options (or in code via AVOptions).
the list of supported options follows โจ
connect_timeout=millisecondsโ connection timeout. fun fact: SRT cannot connect for RTT >1500msec (2 handshake exchanges) with the default connect timeout of3seconds ๐ญ. this option applies to the caller and rendezvous connection modes. the connect timeout is 10 times the value set for the rendezvous mode (which can be used as a workaround for this connection problem with earlier versions).ffs=bytesโ Flight Flag Size (Window Size), in bytes. FFS is actually an internal parameter and you should set it to not less thanrecv_buffer_sizeandmss. the default value is relatively large, so unless you set a very large receiver buffer, you do not need to change this option. default value is25600.inputbw=bytes/secondsโ sender nominal input rate, in bytes per seconds. used along withoheadbw, whenmaxbwis set to relative (0), to calculate maximum sending rate when recovery packets are sent along with the main media stream:inputbw * (100 + oheadbw) / 100. ifinputbwis not set whilemaxbwis set to relative (0), the actual input rate is evaluated inside the library. default value is0.iptos=tosโ IP Type of Service. applies to sender only ๐ซถ. default value is0xB8.ipttl=ttlโ IP Time To Live. applies to sender only. default value is64.latency=microsecondsโ Timestamp-based Packet Delivery Delay. used to absorb bursts of missed packet retransmissions ๐ . this flag sets bothrcvlatencyandpeerlatencyto the same value. note that prior to version1.3.0this is the only flag to set the latency, however this is effectively equivalent to settingpeerlatencywhen side is sender andrcvlatencywhen side is receiver, and the bidirectional stream sending is not supported.listen_timeout=microsecondsโ set socket listen timeout โฐ.maxbw=bytes/secondsโ maximum sending bandwidth, in bytes per seconds.-1infinite (CSRTCC limit is30mbps),0relative to input rate (seeinputbw),>0absolute limit value. default value is0(relative).mode=caller|listener|rendezvousโ connection mode.calleropens client connection.listenerstarts server to listen for incoming connections.rendezvoususe Rendez-Vous connection mode. default value iscaller๐.mss=bytesโ Maximum Segment Size, in bytes. used for buffer allocation and rate calculation using a packet counter assuming fully filled packets. the smallest MSS between the peers is used. this is1500by default in the overall internet ๐. this is the maximum size of the UDP packet and can be only decreased, unless you have some unusual dedicated network settings. default value is1500.nakreport=1|0โ if set to1, Receiver will sendUMSG_LOSSREPORTmessages periodically until a lost packet is retransmitted or intentionally dropped. default value is1.oheadbw=percentsโ recovery bandwidth overhead above input rate, in percents. seeinputbw. default value is25%.passphrase=stringโ HaiCrypt Encryption/Decryption Passphrase string, length from10to79characters ๐. the passphrase is the shared secret between the sender and the receiver. it is used to generate the Key Encrypting Key using PBKDF2 (Password-Based Key Derivation Function). it is used only ifpbkeylenis non-zero. it is used on the receiver only if the received data is encrypted. the configured passphrase cannot be recovered (write-only) ๐ญ.enforced_encryption=1|0โ if true, both connection parties must have the same password set (including empty, that is, with no encryption). if the password doesn't match or only one side is unencrypted, the connection is rejected ๐. default is true.kmrefreshrate=packetsโ the number of packets to be transmitted after which the encryption key is switched to a new key. default is-1.-1means auto (0x1000000in srt library). the range for this option is integers in the0-INT_MAX.kmpreannounce=packetsโ the interval between when a new encryption key is sent and when switchover occurs. this value also applies to the subsequent interval between when switchover occurs and when the old encryption key is decommissioned. default is-1.-1means auto (0x1000in srt library). the range for this option is integers in the0-INT_MAX.snddropdelay=microsecondsโ the sender's extra delay before dropping packets. this delay is added to the default drop delay time interval value.
special value -1: do not drop packets on the sender at all ๐.
payload_size=bytesโ sets the maximum declared size of a packet transferred during the single call to the sending function in Live mode. use0if this value isn't used (which is default in file mode). default is-1(automatic), which typically means MPEG-TS; if you are going to use SRT to send any different kind of payload, such as, for example, wrapping a live stream in very small frames, then you can use a bigger maximum frame size, though not greater than1456bytes.pkt_size=bytesโ alias forpayload_size๐.peerlatency=microsecondsโ the latency value (as described inrcvlatency) that is set by the sender side as a minimum value for the receiver.pbkeylen=bytesโ sender encryption key length, in bytes. only can be set to0,16,24and32. enable sender encryption if not0. not required on receiver (set to0), key size obtained from sender in HaiCrypt handshake. default value is0.rcvlatency=microsecondsโ the time that should elapse since the moment when the packet was sent and the moment when it's delivered to the receiver application in the receiving function โณ. this time should be a buffer time large enough to cover the time spent for sending, unexpectedly extended RTT time, and the time needed to retransmit the lost UDP packet. the effective latency value will be the maximum of this options' value and the value ofpeerlatencyset by the peer side. before version1.3.0this option is only available aslatency.recv_buffer_size=bytesโ set UDP receive buffer size, expressed in bytes.send_buffer_size=bytesโ set UDP send buffer size, expressed in bytes.timeout=microsecondsโ set raise error timeouts for read, write and connect operations. note that the SRT library has internal timeouts which can be controlled separately, the value set here is only a cap on those ๐ .tlpktdrop=1|0โ Too-late Packet Drop. when enabled on receiver, it skips missing packets that have not been delivered in time and delivers the following packets to the application when their time-to-play has come. it also sends a fake ACK to the sender ๐ณ. when enabled on sender and enabled on the receiving peer, the sender drops the older packets that have no chance of being delivered in time. it was automatically enabled in the sender if the receiver supports it.sndbuf=bytesโ set send buffer size, expressed in bytes.rcvbuf=bytesโ set receive buffer size, expressed in bytes.
receive buffer must not be greater than ffs โ ๏ธ.
lossmaxttl=packetsโ the value up to which the Reorder Tolerance may grow. when Reorder Tolerance is> 0, then packet loss report is delayed until that number of packets come in. Reorder Tolerance increases every time a "belated" packet has come, but it wasn't due to retransmission (that is, when UDP packets tend to come out of order), with the difference between the latest sequence and this packet's sequence, and not more than the value of this option. by default it's0, which means that this mechanism is turned off, and the loss report is always sent immediately upon experiencing a "gap" in sequences ๐ฆ.minversionโ the minimum SRT version the peer has to have, bestie. If the peer doesnโt satisfy it, the connection gets rejected, no cap. The version format in hex is0xXXYYZZforx.y.zin human-readable form.streamid=stringโ a string limited to512characters that can be set on the socket before connecting. This stream ID will be able to be retrieved by the listener side from the socket that is returned fromsrt_acceptand was connected by a socket with that set stream ID. SRT does not enforce any special interpretation of the contents of this string. This option doesnโt make sense in Rendezvous connection; the result might be that simply one side will override the value from the other side and itโs the matter of luck which one would win ๐srt_streamid=stringโ alias forstreamidto avoid conflict with ffmpeg command line option. lowkey useful ๐ซถsmoother=live|fileโ the type of Smoother used for the transmission for that socket, which is responsible for the transmission and congestion control. The Smoother type must be exactly the same on both connecting parties, otherwise the connection is rejected.messageapi=1|0โ when set, this socket uses the Message API; otherwise it uses Buffer API. Note that in live mode (seetranstype) thereโs only message API available. In File mode you can choose one of two modes:- Stream API (default, when this option is
false). In this mode you may send as many data as you wish with one sending instruction, or even use dedicated functions that read directly from a file. The internal facility will take care of any speed and congestion control. When receiving, you can also receive as many data as desired, the data not extracted will be waiting for the next call. There is no boundary between data portions in the Stream mode. - Message API. In this mode your single sending instruction passes exactly one piece of data that has boundaries (a message). Contrary to Live mode, this message may span across multiple UDP packets and the only size limitation is that it shall fit as a whole in the sending buffer. The receiver shall use as large buffer as necessary to receive the message, otherwise the message will not be given up. When the message is not complete (not all packets received or there was a packet loss) it will not be given up.
- Stream API (default, when this option is
transtype=live|fileโ sets the transmission type for the socket, in particular, setting this option sets multiple other parameters to their default values as required for a particular transmission type.live: set options as for live transmission. In this mode, you should send by one sending instruction only so many data that fit in one UDP packet, and limited to the value defined first inpayload_size(1316is default in this mode). There is no speed control in this mode, only the bandwidth control, if configured, in order to not exceed the bandwidth with the overhead transmission (retransmitted and control packets).file: set options as for non-live transmission. Seemessageapifor further explanations.
linger=secondsโ the number of seconds that the socket waits for unsent data when closing. Default is-1.-1means auto (off with0seconds in live mode, on with180seconds in file mode). The range for this option is integers in the0-INT_MAX.tsbpd=1|0โ when true, use Timestamp-based Packet Delivery mode. The default behavior depends on the transmission type: enabled in live mode, disabled in file mode.
For more information see: https://github.com/Haivision/srt.
โจ srtp โจ
Secure Real-time Transport Protocol. The accepted options are:
srtp_in_suite,srtp_out_suiteโ select input and output encoding suites. Supported values:
AES_CM_128_HMAC_SHA1_80
SRTP_AES128_CM_HMAC_SHA1_80
AES_CM_128_HMAC_SHA1_32
SRTP_AES128_CM_HMAC_SHA1_32
srtp_in_params,srtp_out_paramsโ set input and output encoding parameters, which are expressed by a base64-encoded representation of a binary block. The first 16 bytes of this binary block are used as master key, the following 14 bytes are used as master salt.
๐ฆ subfile ๐ฆ
Virtually extract a segment of a file or another stream. The underlying stream must be seekable.
Accepted options:
startโ start offset of the extracted segment, in bytes.endโ end offset of the extracted segment, in bytes. If set to0, extract till end of file.
Examples:
Extract a chapter from a DVD VOB file (start and end sectors obtained externally and multiplied by 2048):
subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB
Play an AVI file directly from a TAR archive:
subfile,,start,183241728,end,366490624,,:archive.tar
Play a MPEG-TS file from start offset till end:
subfile,,start,32815239,end,0,,:video.ts
๐ tee ๐
Writes the output to multiple protocols. The individual outputs are separated by |.
tee:file://path/to/local/this.avi|file://path/to/local/that.avi
๐ tcp ๐
Transmission Control Protocol.
The required syntax for a TCP url is:
tcp://<hostname>:<port>[?<options>]
options contains a list of &-separated options of the form key=val. Standard percent-encoding (and using the plus sign for space) can be used to escape keys and values.
Options can also be specified via command line options (or in code via "AVOption"s).
The list of supported options follows.
listen=2|1|0โ listen for an incoming connection.0disables listen,1enables listen in single client mode,2enables listen in multi-client mode. Default value is0.local_addr=addrโ local IP address of a network interface used for tcp socket connect.local_port=portโ local port used for tcp socket connect.timeout=microsecondsโ set raise error timeout, expressed in microseconds. This option is only relevant in read mode: if no data arrived in more than this time interval, raise error.listen_timeout=millisecondsโ set listen timeout, expressed in milliseconds.recv_buffer_size=bytesโ set receive buffer size, expressed bytes.send_buffer_size=bytesโ set send buffer size, expressed bytes.tcp_nodelay=1|0โ setTCP_NODELAYto disable Nagle's algorithm. Default value is0.
Remark: Writing to the socket is currently not optimized to minimize system calls and reduces the efficiency / effect of TCP_NODELAY.
tcp_mss=bytesโ set maximum segment size for outgoing TCP packets, expressed in bytes.
The following example shows how to setup a listening TCP connection with ffmpeg, which is then accessed with ffplay:
ffmpeg -i <input> -f <format> tcp://<hostname>:<port>?listen
ffplay tcp://<hostname>:<port>
๐ tls ๐
Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
The required syntax for a TLS/SSL url is:
tls://<hostname>:<port>[?<options>]
options contains a list of &-separated options of the form key=val. Standard percent-encoding (and using the plus sign for space) can be used to escape keys and values.
Options can also be specified via command line options (or in code via "AVOption"s).
The list of supported options follows.
ca_file,cafile=filenameโ a file containing certificate authority (CA) root certificates to treat as trusted. If the linked TLS library contains a default this might not need to be specified for verification to work, but not all libraries and setups have defaults built in. The file must be in OpenSSL PEM format.tls_verify,verify=1|0โ if enabled, try to verify the peer that we are communicating with. Note, if using OpenSSL, this currently only makes sure that the peer certificate is signed by one of the root certificates in the CA database, but it does not validate that the certificate actually matches the host name we are trying to connect to. (With other backends, the host name is validated as well.) This is disabled by default since it requires a CA database to be provided by the caller in many cases.cert_file,cert=filenameโ a file containing a certificate to use in the handshake with the peer. (When operating as server, in listen mode, this is more often required by the peer, while client certificates only are mandated in certain setups.)key_file,key=filenameโ a file containing the private key for the certificate.listen=1|0โ if enabled, listen for connections on the provided port, and assume the server role in the handshake instead of the client role.http_proxyโ the HTTP proxy to tunnel through, e.g.http://example.com:1234. The proxy must support theCONNECTmethod.
Example command lines:
To create a TLS/SSL server that serves an input stream.
ffmpeg -i <input> -f <format> tls://<hostname>:<port>?listen&cert=<server.crt>&key=<server.key>
To play back a stream from the TLS/SSL server using ffplay:
ffplay tls://<hostname>:<port>
๐ง dtls ๐ง
Datagram Transport Layer Security (DTLS)
The required syntax for a DTLS URL is:
dtls://<hostname>:<port>[?<options>]
options contains a list of &-separated options of the form key=val. Standard percent-encoding (and using the plus sign for space) can be used to escape keys and values.
Options can also be specified via command line options (or in code via "AVOption"s).
DTLS shares most options with TLS, but operates over UDP instead of TCP.
The list of supported options follows.
ca_file,cafile=filenameโ a file containing certificate authority (CA) root certificates to treat as trusted. If the linked TLS library contains a default this might not need to be specified for verification to work, but not all libraries and setups have defaults built in. The file must be in OpenSSL PEM format.tls_verify,verify=1|0โ if enabled, try to verify the peer that we are communicating with. Note, if using OpenSSL, this currently only makes sure that the peer certificate is signed by one of the root certificates in the CA database, but it does not validate that the certificate actually matches the host name we are trying to connect to. This is disabled by default since it requires a CA database to be provided by the caller in many cases.cert_file,cert=filenameโ a file holding the certificate used for the handshake with the peer ๐ (when you're running as server in listen mode, the peer is usually the one asking for this; client certs are only a must in certain setups, iykyk)key_file,key=filenameโ the file with the private key for that certificate ๐cert_pem=stringโ the certificate as a PEM string, right there inline โจkey_pem=stringโ the private key as a PEM string too ๐ซถlisten=1|0โ flip this on and it listens for connections on the port you gave, and takes the server role in the handshake instead of being the client ๐mtu=sizeโ sets the Maximum Transmission Unit (MTU) for DTLS packets ๐ฆuse_srtp=1|0โ enables the use_srtp DTLS extension. This is the whole WebRTC thing: it establishes SRTP encryption keys through the DTLS handshake. Default is disabled ๐external_sock=1|0โ uses an external socket instead of making a shiny new one. Lowkey only makes sense when you're talking to the code via API โ turning this on from the CLI will cause immediate failure, no cap ๐. Default is disabled.
Example command lines:
To create a DTLS server:
ffmpeg -listen 1 -i dtls://<hostname>:<port> <output>
To create a DTLS client and send data to server:
ffmpeg -i <input> -f <format> dtls://<hostname>:<port>
udp
User Datagram Protocol. The chaotic bestie of transport protocols ๐
The required syntax for an UDP URL is:
udp://<hostname>:<port>[?<options>]
options is a list of &-separated options of the form key=val. Standard percent-encoding (and the plus sign for space) can be used to escape keys and values ๐
Options can also be specified via command line options (or in code via AVOptions).
If threading is enabled on your system, a circular buffer is used to store the incoming data, which lets you reduce data loss from UDP socket buffer overruns. The fifo_size and overrun_nonfatal options are the ones tied to this buffer ๐ฆ
The list of supported options follows.
buffer_size=sizeโ sets the UDP maximum socket buffer size in bytes. Used for either the receive or send buffer size, depending on what the socket is doing. Default is 32 KB for output, 384 KB for input. See alsofifo_size๐ธbitrate=bitrateโ if set to nonzero, the output gets the specified constant bitrate, as long as the input has enough packets to sustain it ๐ฅburst_bits=bitsโ when you're usingbitrate, this sets the maximum number of bits in packet bursts.localport=portโ overrides the local UDP port to bind with.localaddr=addrโ local IP address of a network interface used for sending packets or joining multicast groups.pkt_size=sizeโ sets the size in bytes of UDP packets.reuse=1|0โ explicitly allow or disallow reusing UDP sockets.ttl=ttlโ sets the time to live value (multicast only, bestie).dscp=dscpโ sets the 6-bit DSCP field for outgoing packets.connect=1|0โ initializes the UDP socket withconnect(). When you do this, the destination address can't be changed later withff_udp_set_remote_url. If the destination address isn't known at the start, this option can be specified inff_udp_set_remote_urltoo. This lets you find out the source address for the packets withgetsockname, and makes writes return withAVERROR(ECONNREFUSED)if "destination unreachable" comes back. For receiving, the serve is that you only receive packets from the specified peer address/port ๐sources=address[,address]โ only receive packets sent from the specified addresses. With multicast, it also subscribes to multicast traffic coming from these addresses only ๐block=address[,address]โ ignores packets sent from the specified addresses. With multicast, it also excludes the source addresses in the multicast subscription. Not me blocking the haters ๐ซfifo_size=unitsโ sets the UDP receiving circular buffer size, expressed as a number of packets with size of188bytes. If not specified it defaults to7*4096๐overrun_nonfatal=1|0โ survive a UDP receiving circular buffer overrun instead of dying. Default value is0.timeout=microsecondsโ sets the raise error timeout, expressed in microseconds. This one is only relevant in read mode: if no data arrived in more than this time interval, raise error ๐ญbroadcast=1|0โ explicitly allow or disallow UDP broadcasting.
Heads up bestie: broadcasting may not work properly on networks that have broadcast storm protection ๐
Examples
- Use
ffmpegto stream over UDP to a remote endpoint:
ffmpeg -i <input> -f <format> udp://<hostname>:<port>
- Use
ffmpegto stream in mpegts format over UDP using 188 sized UDP packets, with a large input buffer:
ffmpeg -i <input> -f mpegts udp://<hostname>:<port>?pkt_size=188&buffer_size=65535
- Use
ffmpegto receive over UDP from a remote endpoint:
ffmpeg -i udp://[<multicast-address>]:<port> ...
unix
Unix local socket โ the introvert of protocols, it never leaves the machine ๐ง
The required syntax for a Unix socket URL is:
unix://<filepath>
The following parameters can be set via command line options (or in code via AVOptions):
timeoutโ timeout in ms.listenโ creates the Unix socket in listening mode.typeโ select the socket type โจstreamโ corresponds toSOCK_STREAM(reliable stream-oriented)datagramโ corresponds toSOCK_DGRAM(unreliable packet-oriented)seqpacketโ corresponds toSOCK_SEQPACKET(reliable packet-oriented)
pkt_sizeโ maximum packet size for packet-oriented sockets (SOCK_DGRAMandSOCK_SEQPACKET). If greater than zero, this value is used asmax_packet_size. It's ignored forSOCK_STREAM. Default is0.
zmq
ZeroMQ asynchronous messaging, powered by the libzmq library ๐ฆ
This library supports unicast streaming to multiple clients without ever relying on an external server. Main character energy, honestly.
The required syntax for streaming or connecting to a stream is:
zmq:tcp://ip-address:port
Example: create a localhost stream on port 5555:
ffmpeg -re -i input -f mpegts zmq:tcp://127.0.0.1:5555
Multiple clients may connect to the stream using:
ffplay zmq:tcp://127.0.0.1:5555
Streaming to multiple clients is implemented using a ZeroMQ Pub-Sub pattern. The server side binds to a port and publishes data. Clients connect to the server (via IP address/port) and subscribe to the stream. The order in which the server and client start generally does not matter ๐
ffmpeg must be compiled with the --enable-libzmq option to support this protocol.
Options can be set on the ffmpeg/ffplay command line. The following options are supported:
pkt_sizeโ forces the maximum packet size for sending/receiving data. The default value is131,072bytes. On the server side, this sets the maximum size of sent packets via ZeroMQ. On the clients, it sets an internal buffer size for receiving packets.
Note thatpkt_sizeon the clients should be equal to or greater thanpkt_sizeon the server. Otherwise the received message may get truncated, which causes decoding errors ๐ญ
DEVICE OPTIONS
The libavdevice library gives you the exact same interface as libavformat. Like, an input device is treated like a demuxer, an output device is treated like a muxer, and the interface plus the generic device options are the same ones libavformat provides (see the ffmpeg-formats manual) ๐
On top of that, each input or output device may support so-called private options, which are specific to that component ๐
Options may be set by specifying -option value in the FFmpeg tools, or by setting the value explicitly in the device AVFormatContext options, or by using the libavutil/opt.h API for programmatic use โจ
INPUT DEVICES
Input devices are configured elements in FFmpeg that let you access the data coming from a multimedia device attached to your system ๐ฅ
When you configure your FFmpeg build, all the supported input devices are enabled by default. You can list all the available ones using the configure option --list-indevs ๐
You can disable all the input devices using the configure option --disable-indevs, and selectively enable an input device using the option --enable-indev=INDEV, or you can disable a particular input device using the option --disable-indev=INDEV ๐ซ
The option -devices of the ff* tools will display the list of supported input devices.
A description of the currently available input devices follows.
alsa
ALSA (Advanced Linux Sound Architecture) input device ๐ง
To enable this input device during configuration you need libasound installed on your system.
This device lets you capture from an ALSA device. The name of the device to capture has to be an ALSA card identifier.
An ALSA identifier has the syntax:
hw:<CARD>[,<DEV>[,<SUBDEV>]]
where the DEV and SUBDEV components are optional.
The three arguments (in order: CARD,DEV,SUBDEV) specify card number or identifier, device number and subdevice number (-1 means any) ๐ธ
To see the list of cards currently recognized by your system, check the files /proc/asound/cards and /proc/asound/devices ๐ฆ
For example, to capture with ffmpeg from an ALSA device with card id 0, you may run the command:
ffmpeg -f alsa -i hw:0 alsaout.wav
For more information see: http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
Options
sample_rateโ sets the sample rate in Hz. Default is48000.channelsโ sets the number of channels. Default is2.
android_camera
Android camera input device ๐ฑ
This input device uses the Android Camera2 NDK API, which is available on devices with API level 24+. The availability of android_camera is autodetected during configuration ๐
This device lets you capture from all cameras on an Android device that are integrated into the Camera2 NDK API.
The available cameras are enumerated internally and can be selected with the camera_index parameter. The input file string is discarded โ it literally doesn't matter, bestie ๐
Generally the back facing camera has index 0 while the front facing camera has index 1. Selfie mode, activated ๐
Options
video_sizeโ sets the video size, given as a string such as640x480orhd720. Falls back to the first available configuration reported by Android if the requested video size isn't available, or by default.framerateโ sets the video framerate. Falls back to the first available configuration reported by Android if the requested framerate isn't available, or by default (-1).camera_indexโ sets the index of the camera to use. Default is0.input_queue_sizeโ sets the maximum number of frames to buffer. Default is5.
avfoundation
The AVFoundation input device โ aka Apple's actual fave. ๐โจ AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
The input filename has to be given in the following syntax, no cap:
-i "[[VIDEO]:[AUDIO]]"
The first entry selects the video input while the latter selects the audio input. The stream has to be specified by the device name or the device index as shown by the device list. Alternatively, the video and/or audio input device can be chosen by index using the
-video_device_index <INDEX>
and/or
-audio_device_index <INDEX>
, overriding any device name or index given in the input filename. (Yes, the comma is doing its own thing, she's an icon. ๐ )
All available devices can be enumerated by using -list_devices true, listing all device names and corresponding indices.
There are two device name aliases, and they are lowkey everything:
"default"โ Select the AVFoundation default device of the corresponding type."none"โ Do not record the corresponding media type. This is equivalent to specifying an empty device name or index.
Options
AVFoundation supports the following options, bestie:
-list_devices <TRUE|FALSE>โ If set to true, a list of all available input devices is given showing all device names and indices.-video_device_index <INDEX>โ Specify the video device by its index. Overrides anything given in the input filename.-audio_device_index <INDEX>โ Specify the audio device by its index. Overrides anything given in the input filename.-pixel_format <FORMAT>โ Request the video device to use a specific pixel format. If the specified format is not supported, a list of available formats is given and the first one in this list is used instead. Available pixel formats are:"monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0, bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10, yuv420p, nv12, yuyv422, gray"-framerateโ Set the grabbing frame rate. Default is"ntsc", corresponding to a frame rate of"30000/1001".-video_sizeโ Set the video frame size.-capture_cursorโ Capture the mouse pointer. Default is0.-capture_mouse_clicksโ Capture the screen mouse clicks. Default is0.-capture_raw_dataโ Capture the raw device data. Default is0. Using this option may result in receiving the underlying data delivered to the AVFoundation framework. E.g. for muxed devices that sends raw DV data to the framework (like tape-based camcorders), setting this option to false results in extracted video frames captured in the designated pixel format only. Setting this option to true results in receiving the raw DV stream untouched.
Examples
- Print the list of AVFoundation supported devices and exit:
$ ffmpeg -f avfoundation -list_devices true -i ""
- Record video from video device 0 and audio from audio device 0 into
out.avi:
$ ffmpeg -f avfoundation -i "0:0" out.avi
- Record video from video device 2 and audio from audio device 1 into
out.avi:
$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
- Record video from the system default video device using the pixel format
bgr0and do not record any audio intoout.avi:
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
- Record raw DV data from a suitable input device and write the output into
out.dv:
$ ffmpeg -f avfoundation -capture_raw_data true -i "zr100:none" out.dv
decklink
The decklink input device provides capture capabilities for Blackmagic DeckLink devices. ๐ฅ๐ฅ
To enable this input device, you need the Blackmagic DeckLink SDK and you need to configure with the appropriate "--extra-cflags" and "--extra-ldflags". On Windows, you need to run the IDL files through widl.
DeckLink is very picky about the formats it supports โ she has standards, respect them. ๐
Pixel format of the input can be set with raw_format. Framerate and video size must be determined for your device with -list_formats 1. Audio sample rate is always 48 kHz and the number of channels can be 2, 8 or 16. Note that all audio channels are bundled in one single audio track.
Options
list_devicesโ If set to true, print a list of devices and exit. Defaults to false. This option is deprecated, please use the"-sources"option of ffmpeg to list the available input devices.list_formatsโ If set to true, print a list of supported formats and exit. Defaults to false.format_code <FourCC>โ This sets the input video format to the format given by the FourCC. To see the supported values of your device(s) uselist_formats. Note that there is a FourCC'pal 'that can also be used aspal(3 letters). Default behavior is autodetection of the input video format, if the hardware supports it.raw_formatโ Set the pixel format of the captured video. Available values are:autoโ This is the default which means 8-bit YUV 422 or 8-bit ARGB if format autodetection is used, 8-bit YUV 422 otherwise.uyvy422โ 8-bit YUV 422.yuv422p10โ 10-bit YUV 422.argbโ 8-bit RGB.bgraโ 8-bit RGB.rgb10โ 10-bit RGB.
teletext_linesโ If set to nonzero, an additional teletext stream will be captured from the vertical ancillary data. Both SD PAL (576i) and HD (1080i or 1080p) sources are supported. In case of HD sources, OP47 packets are decoded.
This option is a bitmask of the SD PAL VBI lines captured, specifically lines 6 to 22, and lines 318 to 335. Line 6 is the LSB in the mask. Selected lines which do not contain teletext information will be ignored. You can use the special all constant to select all possible lines, or standard to skip lines 6, 318 and 319, which are not compatible with all receivers.
For SD sources, ffmpeg needs to be compiled with "--enable-libzvbi". For HD sources, on older (pre-4K) DeckLink card models you have to capture in 10 bit mode.
channelsโ Defines number of audio channels to capture. Must be2,8or16. Defaults to2.duplex_modeโ Sets the decklink device duplex/profile mode. Must beunset,half,full,one_sub_device_full,one_sub_device_half,two_sub_device_full,four_sub_device_half. Defaults tounset.
Note: DeckLink SDK 11.0 have replaced the duplex property by a profile property. For the DeckLink Duo 2 and DeckLink Quad 2, a profile is shared between any 2 sub-devices that utilize the same connectors. For the DeckLink 8K Pro, a profile is shared between all 4 sub-devices. So DeckLink 8K Pro support four profiles.
Valid profile modes for DeckLink 8K Pro (with DeckLink SDK >= 11.0): one_sub_device_full, one_sub_device_half, two_sub_device_full, four_sub_device_half
Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2: half, full
timecode_formatโ Timecode type to include in the frame and video stream metadata. Must benone,rp188vitc,rp188vitc2,rp188ltc,rp188hfr,rp188any,vitc,vitc2, orserial. Defaults tonone(not included).
In order to properly support 50/60 fps timecodes, the ordering of the queried timecode types for rp188any is HFR, VITC1, VITC2 and LTC for >30 fps content. Note that this is slightly different to the ordering used by the DeckLink API, which is HFR, VITC1, LTC, VITC2. (iykyk ๐)
video_inputโ Sets the video input source. Must beunset,sdi,hdmi,optical_sdi,component,compositeors_video. Defaults tounset.audio_inputโ Sets the audio input source. Must beunset,embedded,aes_ebu,analog,analog_xlr,analog_rcaormicrophone. Defaults tounset.video_ptsโ Sets the video packet timestamp source. Must bevideo,audio,reference,wallclockorabs_wallclock. Defaults tovideo.audio_ptsโ Sets the audio packet timestamp source. Must bevideo,audio,reference,wallclockorabs_wallclock. Defaults toaudio.draw_barsโ If set to true, color bars are drawn in the event of a signal loss. Defaults to true. This option is deprecated, please use the"signal_loss_action"option.signal_loss_actionโ Sets the action to take in the event of a signal loss. Accepts one of the following values:1, noneโ Do nothing on signal loss. This usually results in black frames.2, barsโ Draw color bars on signal loss. Only supported for 8-bit input signals.3, repeatโ Repeat the last video frame on signal loss.
Defaults to bars.
queue_sizeโ Sets maximum input buffer size in bytes. If the buffering reaches this value, incoming frames will be dropped. Defaults to1073741824.audio_depthโ Sets the audio sample bit depth. Must be16or32. Defaults to16.decklink_copytsโ If set to true, timestamps are forwarded as they are without removing the initial offset. Defaults to false.timestamp_alignโ Capture start time alignment in seconds. If set to nonzero, input frames are dropped till the system timestamp aligns with configured value. Alignment difference of up to one frame duration is tolerated. This is useful for maintaining input synchronization across N different hardware devices deployed for 'N-way' redundancy. The system time of different hardware devices should be synchronized with protocols such as NTP or PTP, before using this option. Note that this method is not foolproof. In some border cases input synchronization may not happen due to thread scheduling jitters in the OS. Either sync could go wrong by 1 frame or in a rarer casetimestamp_alignseconds. Defaults to0.wait_for_tc (bool)โ Drop frames till a frame with timecode is received. Sometimes serial timecode isn't received with the first input frame. If that happens, the stored stream timecode will be inaccurate. If this option is set to true, input frames are dropped till a frame with timecode is received. Optiontimecode_formatmust be specified. Defaults to false.enable_klv(bool)โ If set to true, extracts KLV data from VANC and outputs KLV packets. KLV VANC packets are joined based on MID and PSC fields and aggregated into one KLV packet. Defaults to false.
Examples
- List input devices:
ffmpeg -sources decklink
- List supported formats:
-a, ... no wait, we're doing examples bestie, not options ๐ญ
ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
- โจ Capture a video clip at 1080i50:
ffmpeg -format_code Hi50 -f decklink -i 'Intensity Pro' -c:a copy -c:v copy output.avi
- ๐ Capture a video clip at 1080i50, but make it 10 bit:
ffmpeg -raw_format yuv422p10 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi
- ๐ Capture a video clip at 1080i50 with a full 16 audio channels:
ffmpeg -channels 16 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi
๐ธ dshow ๐ธ
Okay so this one is the Windows DirectShow input device bestie. ๐ช
DirectShow support is only a thing when FFmpeg gets built with the mingw-w64 project. And rn? Only audio and video devices are supported โ that's the whole menu, no cap.
You can open multiple devices as separate inputs, but plot twist: you can also open them on the same input, which should improve the synchronism between them. Slay, honestly. ๐
The input name has to be in this format:
<TYPE>=<NAME>[:<TYPE>=<NAME>]
where TYPE can be either audio or video, and NAME is the device's name or alternative name. (Yes, the original says "alternative name.." with two dots โ we're keeping the double dots, it's part of the vibe now ๐)
๐ Options ๐
If you specify no options at all, the device's defaults get used. And if the device doesn't support the options you're asking for? It will fail to open. Periodt. No partial credit.
video_sizeโ sets the video size in the captured video.framerateโ sets the frame rate in the captured video.sample_rateโ sets the sample rate (in Hz) of the captured audio.sample_sizeโ sets the sample size (in bits) of the captured audio.channelsโ sets the number of channels in the captured audio.list_devicesโ if you set it to true, it prints a list of devices and then exits. Iconic lil recon mission. ๐ต๏ธlist_optionsโ if set to true, prints a list of the selected device's options and exits.video_device_numberโ sets the video device number for devices that share the same name (starts at0, defaults to0).audio_device_numberโ sets the audio device number for devices that share the same name (starts at0, defaults to0).pixel_formatโ picks the pixel format DirectShow uses. Heads up: this may only be set when the video codec is not set, or is set torawvideo.audio_buffer_sizeโ sets the audio device buffer size in milliseconds (which can directly impact latency, depending on the device, so likeโฆ pick wisely). Defaults to using the audio device's own default buffer size (typically some multiple of500ms). Setting this value too low can degrade performance โ don't do that to yourself ๐ญ. See also <http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx>video_pin_nameโ selects which video capture pin to use, by name or alternative name.audio_pin_nameโ selects which audio capture pin to use, by name or alternative name.crossbar_video_input_pin_numberโ selects the video input pin number for a crossbar device. This gets routed to the crossbar device's Video Decoder output pin. โ ๏ธ Note that changing this value can affect future invocations (it sets a new default) until a system reboot happens. So it's giving "haunted setting," be careful.crossbar_audio_input_pin_numberโ selects the audio input pin number for a crossbar device. This gets routed to the crossbar device's Audio Decoder output pin. Same warning bestie: changing it can affect future invocations (new default gets set) until the system reboots.show_video_device_dialogโ if set to true, then before capture starts, it pops up a display dialog for the end user so they can manually change video filter properties and configurations. Note that for crossbar devices, adjusting values in this dialog may sometimes be needed to toggle between PAL (25 fps) and NTSC (29.97) input frame rates, sizes, interlacing, etc. Changing these values can enable different scan rates/frame rates and avoid green bars at the bottom, flickering scan lines, etc. ๐ฉ And note that with some devices, changing these properties can also affect future invocations (sets new defaults) until a system reboot occurs. Reboot-core fr.show_audio_device_dialogโ if set to true, before capture starts, pops up a display dialog for the end user so they can manually change audio filter properties and configurations.show_video_crossbar_connection_dialogโ if set to true, before capture starts, pops up a display dialog for the end user so they can manually modify crossbar pin routings when it opens a video device.show_audio_crossbar_connection_dialogโ if set to true, before capture starts, pops up a display dialog for the end user so they can manually modify crossbar pin routings when it opens an audio device.show_analog_tv_tuner_dialogโ if set to true, before capture starts, pops up a display dialog for the end user so they can manually modify TV channels and frequencies.show_analog_tv_tuner_audio_dialogโ if set to true, before capture starts, pops up a display dialog for the end user so they can manually modify TV audio (think mono vs. stereo, Language A, B or C).audio_device_loadโ loads an audio capture filter device from a file instead of searching for it by name. It may load extra parameters too, if the filter supports serializing its properties. To use this you have to specify an audio capture source, but honestly it can be anything โ even a fake one. ๐audio_device_saveโ saves the currently used audio capture filter device and its parameters (if the filter supports it) to a file. If a file with the same name already exists, it gets overwritten, sorry babe.video_device_loadโ loads a video capture filter device from a file instead of searching it by name. It may load extra parameters too, if the filter supports serializing its properties. To use this you have to specify a video capture source, but it can be anything โ even a fake one.video_device_saveโ saves the currently used video capture filter device and its parameters (if the filter supports it) to a file. If a file with the same name exists, it will be overwritten. ๐use_video_device_timestampsโ if set to false, the timestamp for video frames gets derived from the wallclock instead of the timestamp the capture device hands over. This is the workaround for devices that give you unreliable timestamps. Ty for your service. ๐ซถ
๐ฆ Examples ๐ฆ
- Print the list of DirectShow supported devices and exit:
$ ffmpeg -list_devices true -f dshow -i dummy
- Open the video device
Camera:
$ ffmpeg -f dshow -i video="Camera"
- Open the second video device that's also named
Camera:
$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
- Open video device
Cameraand audio deviceMicrophonetogether:
$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
- Print the list of supported options on the selected device and exit:
$ ffmpeg -list_options true -f dshow -i video="Camera"
- Specify pin names to capture by name or alternative name, and specify an alternative device name:
$ ffmpeg -f dshow -audio_pin_name "Audio Out" -video_pin_name 2 -i video=video="@device_pnp_\\?\pci#ven_1a0a&dev_6200&subsys_62021461&rev_01#4&e2c7dd6&0&00e1#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\{ca465100-deb0-4d59-818f-8c477184adf6}":audio="Microphone"
- Configure a crossbar device, specifying crossbar pins, and let the user adjust video capture properties at startup:
$ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0
-crossbar_audio_input_pin_number 3 -i video="AVerMedia BDA Analog Capture":audio="AVerMedia BDA Analog Capture"
๐ง fbdev ๐ง
This is the Linux framebuffer input device. ๐ง
The Linux framebuffer is a graphic hardware-independent abstraction layer for showing graphics on a computer monitor โ typically on the console. You access it through a file device node, usually /dev/fb0.
Wanna go deeper? Read the file Documentation/fb/framebuffer.txt that's included in the Linux source tree. ๐
See also <http://linux-fbdev.sourceforge.net/>, and fbset(1).
To record from the framebuffer device /dev/fb0 with ffmpeg:
ffmpeg -f fbdev -framerate 10 -i /dev/fb0 out.avi
And you can grab a single screenshot image with this command:
ffmpeg -f fbdev -framerate 1 -i /dev/fb0 -frames:v 1 screenshot.jpeg
โญ Options โญ
framerateโ sets the frame rate. Default is25.
๐ gdigrab ๐
The Win32 GDI-based screen capture device. This one lets you capture a region of the display on Windows. ๐ฅ๏ธโจ
Amongst the options for the input filenames are such elements as:
desktop
or
title=<window_title>
or
hwnd=<window_hwnd>
So here's the tea โ: the first option captures the entire desktop, or a fixed region of the desktop. The second and third options instead capture the contents of a single window, regardless of where that window is sitting on the screen. Main character energy, honestly โ it doesn't care about its position.
For example, to grab the entire desktop using ffmpeg:
ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
Grab a 640x480 region at position "10,20":
ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
Grab the contents of the window named "Calculator":
ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
๐ Options ๐
draw_mouseโ specifies whether to draw the mouse pointer. Use the value0to not draw the pointer. Default value is1. ๐ฑ๏ธframerateโ sets the grabbing frame rate. Default value is"ntsc", which corresponds to a frame rate of"30000/1001".show_regionโ shows the grabbed region on screen.
If show_region is specified with 1, then the grabbing region gets indicated on screen. With this option it's super easy to know what's actually being grabbed if you're only grabbing a portion of the screen. ๐
โ ๏ธ Note that show_region is incompatible with grabbing the contents of a single window. Pick a lane bestie.
For example:
ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
video_sizeโ sets the video frame size. The default is to capture the full screen ifdesktopis selected, or the full window size iftitle=window_titleis selected.offset_xโ when capturing a region withvideo_size, sets the distance from the left edge of the screen or desktop.
๐ Note that the offset calculation is from the top left corner of the primary monitor on Windows. So if you've got a monitor positioned to the left of your primary monitor, you'll need to use a negative offset_x value to move the region over to that monitor. Sneaky but true.
offset_yโ when capturing a region withvideo_size, sets the distance from the top edge of the screen or desktop.
Quick note before we dive back in, bestie: the offset math is measured from the top-left corner of the primary monitor on Windows. So if you've got a monitor sitting above your primary one, you're gonna need a negative offset_y value to push the region up onto that monitor. Sneaky, but that's how it works. ๐
iec61883
FireWire DV/HDV input device, powered by libiec61883. ๐
To switch this input device on, you need libiec61883, libraw1394 and libavc1394 all installed on your system. Then configure with "--enable-libiec61883" to actually compile it in.
The iec61883 capture device supports grabbing from a video device connected over IEEE1394 (FireWire), using libiec61883 plus the new Linux FireWire stack (juju). This is the default DV/HDV input method in Linux Kernel 2.6.37 and later โ because the old FireWire stack got yeeted. ๐
Just point it at the FireWire port you wanna use as the input file, or say "auto" and it'll pick the first port that's connected.
Options
dvtypeโ overrides the DV/HDV autodetection. Only use this when autodetection is being a hater, or when you specifically wanna forbid a different device type. Treating a DV device as HDV (or the other way round) will not work and results in undefined behavior. Supported values:auto,dv, andhdv.dvbufferโ sets the max buffer size for incoming data, in frames. For DV this is an exact value. For HDV it is not frame exact, because HDV doesn't have a fixed frame size.dvguidโ picks the capture device by specifying its GUID. It'll only capture from that exact device and fails if no device with the given GUID is found. Super useful when you've got multiple devices plugged in at once. Go peek at/sys/bus/firewire/devicesto find the GUIDs. ๐
Examples
- Grab and show the input of a FireWire DV/HDV device:
ffplay -f iec61883 -i auto
- Grab and record the input of a FireWire DV/HDV device, using a packet buffer of
100000packets if the source is HDV:
ffmpeg -f iec61883 -i auto -dvbuffer 100000 out.mpg
jack
The JACK input device. ๐ง
To enable it at configure time you need libjack installed on your system.
A JACK input device creates one or more JACK writable clients โ one for each audio channel โ named client_name:input_N, where client_name is the name the application provides and N is a number identifying the channel. Each writable client sends the data it acquires to the FFmpeg input device.
Once you've made one or more JACK readable clients, you gotta connect them to one or more JACK writable clients. ๐
To connect or disconnect JACK clients you can use the jack_connect and jack_disconnect programs, or do it through a graphical interface โ qjackctl, for example.
To list the JACK clients and their properties, just invoke jack_lsp.
Here's an example showing how to capture a JACK readable client with ffmpeg:
# Create a JACK writable client with name "ffmpeg".
$ ffmpeg -f jack -i ffmpeg -y out.wav
# Start the sample jack_metro readable client.
$ jack_metro -b 120 -d 0.2 -f 4000
# List the current JACK clients.
$ jack_lsp -c
system:capture_1
system:capture_2
system:playback_1
system:playback_2
ffmpeg:input_1
metro:120_bpm
# Connect metro to the ffmpeg writable client.
$ jack_connect metro:120_bpm ffmpeg:input_1
For more info, read: <http://jackaudio.org/> ๐
Options
channelsโ sets the number of channels. Default is2.
kmsgrab
The KMS video input device. ๐ฅ๏ธ
It captures the KMS scanout framebuffer tied to a specified CRTC or plane as a DRM object, which can then be passed along to other hardware functions.
Requires either DRM master or CAP_SYS_ADMIN to run. ๐
If you don't understand what all of that means, you probably don't want this. Look at x11grab instead. No cap. ๐
Options
deviceโ the DRM device to capture on. Defaults to/dev/dri/card0.formatโ pixel format of the framebuffer. This can be autodetected if you're running Linux 5.7 or later, but it needs to be provided on earlier versions. Defaults tobgr0, which is the most common format used by the Linux console and Xorg X server.format_modifierโ format modifier to signal on output frames. This is necessary to import correctly into some APIs. It can be autodetected on Linux 5.7 or later, but you'll need to provide it explicitly when it's needed on earlier versions. Check the libdrm documentation for the possible values.crtc_idโ KMS CRTC ID that defines the capture source. The first active plane on the given CRTC gets used.plane_idโ KMS plane ID that defines the capture source. Defaults to the first active plane found if neithercrtc_idnorplane_idare specified.framerateโ the framerate to capture at. This is not synchronised to any page flipping or framebuffer changes โ it literally just defines the interval at which the framebuffer is sampled. Sampling faster than the framebuffer update rate will generate independent frames with the same content. Defaults to30.
Examples
- Capture from the first active plane, download the result to normal frames, and encode. This will only work if the framebuffer is both linear and mappable โ if not, the result may be scrambled or fail to download. ๐ญ
ffmpeg -f kmsgrab -i - -vf 'hwdownload,format=bgr0' output.mp4
- Capture from CRTC ID
42at 60fps, map the result to VAAPI, convert to NV12, and encode as H.264:
ffmpeg -crtc_id 42 -framerate 60 -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12' -c:v h264_vaapi output.mp4
- Wanna capture only part of a plane? Just crop the output โ this can be used to capture a single window, as long as it has a known absolute position and size. For example, to capture and encode the middle quarter of a
1920x1080plane:
ffmpeg -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,crop=960:540:480:270,scale_vaapi=960:540:nv12' -c:v h264_vaapi output.mp4
lavfi
The Libavfilter input virtual device. ๐ฆ
This input device reads data from the open output pads of a libavfilter filtergraph.
For each filtergraph open output, the input device creates a corresponding stream mapped to the generated output. The filtergraph itself is specified through the graph option.
Options
graphโ specifies the filtergraph to use as input. Each video open output must be labelled with a unique string of the form"outN", whereNis a number starting from0corresponding to the mapped input stream generated by the device. The first unlabelled output is automatically assigned to the"out0"label, but all the others need to be specified explicitly.
The suffix "+subcc" can be appended to the output label to create an extra stream with the closed captions packets attached to that output (experimental; only for EIA-608 / CEA-708 for now ๐งช). The subcc streams are created after all the normal streams, in the order of the corresponding stream. For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19. Wild, right? ๐
If not specified, defaults to the filename specified for the input device.
graph_fileโ sets the filename of the filtergraph to be read and sent to the other filters. Syntax of the filtergraph is the same as the one specified by the optiongraph.dumpgraphโ dump graph tostderr.
Examples
- Create a color video stream and play it back with ffplay:
ffplay -f lavfi -graph "color=c=pink [out0]" dummy
- Same as the previous example, but use the filename for specifying the graph description, and omit the
"out0"label:
ffplay -f lavfi color=c=pink
- Create three different video test filtered sources and play them:
ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
- Read an audio stream from a file using the
amoviesource and play it back with ffplay:
ffplay -f lavfi "amovie=test.wav"
- Read an audio stream and a video stream and play it back with ffplay:
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
- Dump decoded frames to images and Closed Captions to an RCWT backup:
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rcwt subcc.bin
libcdio
Audio-CD input device based on libcdio. ๐ฟ
To enable this input device at configure time you need libcdio installed on your system. It requires the configure option "--enable-libcdio".
This device lets you play and grab from an Audio-CD. Iconic, honestly.
For example, to copy with ffmpeg the entire Audio-CD in /dev/sr0, you may run:
ffmpeg -f libcdio -i /dev/sr0 cd.wav
Options
speedโ sets drive reading speed. Default value is0.
The speed is specified in CD-ROM speed units. The speed is set through the libcdio cdio_cddap_speed_set function. On many CD-ROM drives, specifying a value that's too large will just result in using the fastest speed.
paranoia_modeโ sets paranoia recovery mode flags. It accepts one of the following values:disableverifyoverlapneverskipfull
Default value is disable.
For more info about the available recovery modes, consult the paranoia project documentation. ๐
libdc1394
IIDC1394 input device, based on libdc1394 and libraw1394.
Requires the configure option "--enable-libdc1394".
Options
framerateโ sets the frame rate. Default is"ntsc", corresponding to a frame rate of"30000/1001".pixel_formatโ selects the pixel format. Default is"uyvy422".video_sizeโ sets the video size given as a string such as"640x480"or"hd720". Default is"qvga".
openal
The OpenAL input device provides audio capture on all systems with a working OpenAL 1.1 implementation. ๐๏ธ
To enable this input device at configure time, you need the OpenAL headers and libraries installed on your system, and you need to configure FFmpeg with "--enable-openal".
okay so your OpenAL headers and libraries should come bundled with your OpenAL implementation, or you can grab them as an extra download (an SDK, if we're being official about it ๐). Depending on your install you might need to pass extra flags via --extra-cflags and --extra-ldflags so the build system can actually locate the OpenAL headers and libraries. lowkey a scavenger hunt but we move ๐
An incomplete list of OpenAL implementations follows (yes, incomplete, there are more out there, this is just the starters):
- Creative โ the official Windows implementation, serving up hardware acceleration with supported devices plus a software fallback. See
http://openal.org/. - OpenAL Soft โ portable, open source (LGPL) software implementation. Comes with backends for the most common sound APIs on the Windows, Linux, Solaris, and BSD operating systems. See
http://kcat.strangesoft.net/openal.html. - Apple โ OpenAL is part of Core Audio, the official Mac OS X Audio interface. See
http://developer.apple.com/technologies/mac/audio-and-video.html
This device lets you capture from an audio input device that's handled through OpenAL. ๐ง
You need to specify the name of the device to capture in the provided filename. If you pass the empty string, the device will automatically select the default device, no thoughts head empty, it just handles it โจ. You can get the list of the supported devices by using the option list_devices.
Options ๐ธ
channelsโ sets the number of channels in the captured audio. Only the values1(monaural) and2(stereo) are currently supported. Defaults to2.sample_sizeโ sets the sample size (in bits) of the captured audio. Only the values8and16are currently supported. Defaults to16.sample_rateโ sets the sample rate (in Hz) of the captured audio. Defaults to44.1k.list_devicesโ if set to true, prints a list of devices and exits. Defaults to false.
Examples ๐ฆ
Print the list of OpenAL supported devices and exit:
$ ffmpeg -list_devices true -f openal -i dummy out.ogg
Capture from the OpenAL device DR-BT101 via PulseAudio:
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
Capture from the default device (note the empty string '' as filename โ yes, literally nothing, iconic):
$ ffmpeg -f openal -i '' out.ogg
Capture from two devices simultaneously, writing to two different files, within the same ffmpeg command:
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
Note: not all OpenAL implementations support multiple simultaneous capture โ try the latest OpenAL Soft if the above does not work. ๐
oss ๐
Open Sound System input device.
The filename you hand to the input device is the device node representing the OSS input device, and is usually set to /dev/dsp.
For example to grab from /dev/dsp using ffmpeg use the command:
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
For more information about OSS see: http://manuals.opensound.com/usersguide/dsp.html
Options ๐
sample_rateโ sets the sample rate in Hz. Default is48000.channelsโ sets the number of channels. Default is2.
pulse ๐ซถ
PulseAudio input device.
To enable this output device you need to configure FFmpeg with --enable-libpulse. (output device, yes, that's what it says, no I will not be taking questions ๐)
The filename you provide to the input device is a source device or the string "default".
To list the PulseAudio source devices and their properties you can invoke the command pactl list sources.
More information about PulseAudio can be found on http://www.pulseaudio.org.
Options ๐
serverโ connects to a specific PulseAudio server, specified by an IP address. Default server is used when not provided.nameโ specifies the application name PulseAudio will use when showing active clients, by default it is the"LIBAVFORMAT_IDENT"string.stream_nameโ specifies the stream name PulseAudio will use when showing active streams, by default it is"record".sample_rateโ specifies the samplerate in Hz, by default 48kHz is used.channelsโ specifies the channels in use, by default2(stereo) is set.frame_sizeโ this option does nothing and is deprecated. it's giving ghost ๐ป it's literally not realfragment_sizeโ specifies the size in bytes of the minimal buffering fragment in PulseAudio, it will affect the audio latency. By default it is set to 50 ms amount of data.wallclockโ sets the initial PTS using the current time. Default is1.
Examples ๐
Record a stream from default device:
ffmpeg -f pulse -i default /tmp/pulse.wav
sndio ๐
sndio input device.
To enable this input device during configuration you need libsndio installed on your system.
The filename you provide to the input device is the device node representing the sndio input device, and is usually set to /dev/audio0.
For example to grab from /dev/audio0 using ffmpeg use the command:
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
Options โญ
sample_rateโ sets the sample rate in Hz. Default is48000.channelsโ sets the number of channels. Default is2.
video4linux2, v4l2 ๐
Video4Linux2 input video device.
v4l2 can be used as alias for video4linux2. same energy, shorter name, slay โจ
If FFmpeg is built with v4l-utils support (by using the --enable-libv4l2 configure option), it is possible to use it with the -use_libv4l2 input device option.
The name of the device to grab is a file device node. Usually Linux systems tend to automatically create such nodes when the device (e.g. an USB webcam) is plugged into the system, and it has a name of the kind /dev/videoN, where N is a number associated to the device.
Video4Linux2 devices usually support a limited set of widthxheight sizes and frame rates. You can check which are supported using -list_formats all for Video4Linux2 devices. Some devices, like TV cards, support one or more standards. It is possible to list all the supported standards using -list_standards all.
The time base for the timestamps is 1 microsecond. Depending on the kernel version and configuration, the timestamps may be derived from the real time clock (origin at the Unix Epoch) or the monotonic clock (origin usually at boot time, unaffected by NTP or manual changes to the clock). The -timestamps abs or -ts abs option can be used to force conversion into the real time clock. โฐ no cap, clocks are complicated
Some usage examples of the video4linux2 device with ffmpeg and ffplay:
- List supported formats for a video4linux2 device:
ffplay -f video4linux2 -list_formats all /dev/video0
- Grab and show the input of a video4linux2 device:
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
- Grab and record the input of a video4linux2 device, leave the frame rate and size as previously set:
ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
For more information about Video4Linux, check http://linuxtv.org/.
Options ๐
standardโ sets the standard. Must be the name of a supported standard. To get a list of the supported standards, use thelist_standardsoption.channelโ sets the input channel number. Default to-1, which means using the previously selected channel.video_sizeโ sets the video frame size. The argument must be a string in the formWIDTHxHEIGHTor a valid size abbreviation.pixel_formatโ selects the pixel format (only valid for raw video input).input_formatโ sets the preferred pixel format (for raw video) or a codec name. This option allows one to select the input format, when several are available.framerateโ sets the preferred video frame rate.list_formatsโ lists available formats (supported pixel formats, codecs, and frame sizes) and exits.
Available values are:
allโ show all available (compressed and non-compressed) formats.rawโ show only raw video (non-compressed) formats.compressedโ show only compressed formats.
list_standardsโ lists supported standards and exits.
Available values are:
allโ show all supported standards.
timestamps,tsโ sets type of timestamps for grabbed frames.
Available values are:
defaultโ use timestamps from the kernel.absโ use absolute timestamps (wall clock).mono2absโ force conversion from monotonic to absolute timestamps.
Default value is "default".
use_libv4l2โ use libv4l2 (v4l-utils) conversion functions. Default is0.
vfwcap ๐ฌ
VfW (Video for Windows) capture input device.
The filename passed as input is the capture driver number, ranging from 0 to 9. You may use "list" as filename to print a list of drivers. Any other filename will be interpreted as device number 0. (so like, just don't be weird with it and you'll be fine ๐ญ)
Options ๐ธ
video_sizeโ sets the video frame size.framerateโ sets the grabbing frame rate. Default value is"ntsc", corresponding to a frame rate of"30000/1001".
x11grab ๐ฅ๏ธโจ
X11 video input device.
To enable this input device during configuration you need libxcb installed on your system. It will be automatically detected during configuration. it just knows, main character energy fr
This device allows one to capture a region of an X11 display.
The filename passed as input has the syntax:
[<hostname>]:<display_number>.<screen_number>[+<x_offset>,<y_offset>]
hostname:display_number.screen_number specifies the X11 display name of the screen to grab from. hostname can be omitted, and defaults to "localhost". The environment variable DISPLAY contains the default display name.
x_offset and y_offset specify the offsets of the grabbed area with respect to the top-left border of the X11 screen. They default to 0.
Check the X11 documentation (e.g. man X) for more detailed information.
Use the xdpyinfo program for getting basic information about the properties of your X11 display (e.g. grep for "name" or "dimensions").
For example to grab from :0.0 using ffmpeg:
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
Grab at position "10,20":
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
Options ๐
select_regionโ specifies whether to select the grabbing area graphically using the pointer. A value of1prompts the user to select the grabbing area graphically by clicking and dragging. A single click with no dragging will select the whole screen. A region with zero width or height will also select the whole screen. This option overwrites thevideo_size,grab_x, andgrab_yoptions. Default value is0.draw_mouseโ specifies whether to draw the mouse pointer. A value of0specifies not to draw the pointer. Default value is1.follow_mouseโ makes the grabbed area follow the mouse, bestie ๐ The argument can be"centered"or a number of pixelsPIXELS.
When itโs specified with "centered", the grabbing region follows the mouse pointer and keeps the pointer at the center of the region; otherwise, the region follows only when the mouse pointer reaches within PIXELS (greater than zero) to the edge of the region.
For example:
ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
To follow only when the mouse pointer reaches within 100 pixels to the edge:
ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
framerateโ sets the grabbing frame rate. Default value isntsc, corresponding to a frame rate of30000/1001โจshow_regionโ shows the grabbed region on screen.
If show_region is specified with 1, then the grabbing region will be indicated on screen. With this option, itโs easy to know whatโs being grabbed if only a portion of the screen is grabbed ๐
region_borderโ sets the region border thickness if-show_region 1is used. Range is1to128and default is3(XCB-based x11grab only).
For example:
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
With follow_mouse:
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
window_idโ grabs this window instead of the whole screen. Default value is0, which maps to the whole screen (root window).
The id of a window can be found using the xwininfo program, possibly with options -tree and -root.
If the window is later enlarged, the new area is not recorded. Video ends when the window is closed, unmapped (i.e., iconified) or shrunk beyond the video size (which defaults to the initial window size).
This option disables options follow_mouse and select_region ๐
video_sizeโ sets the video frame size. Default is the full desktop or window.grab_x,grab_yโ set the grabbing region coordinates. They are expressed as offset from the top left corner of the X11 window and correspond to thex_offsetandy_offsetparameters in the device name. The default value for both options is0.
๐ OUTPUT DEVICES ๐
Output devices are configured elements in FFmpeg that can write multimedia data to an output device attached to your system ๐ซถ
When you configure your FFmpeg build, all the supported output devices are enabled by default. You can list all available ones using the configure option --list-outdevs โจ
You can disable all the output devices using the configure option --disable-outdevs, and selectively enable an output device using the option --enable-outdev=OUTDEV, or you can disable a particular input device using the option --disable-outdev=OUTDEV.
The option -devices of the ff* tools will display the list of enabled output devices.
A description of the currently available output devices follows ๐
๐ง alsa
ALSA (Advanced Linux Sound Architecture) output device.
Examples
- Play a file on default ALSA device:
ffmpeg -i INPUT -f alsa default
- Play a file on soundcard 1, audio device 7:
ffmpeg -i INPUT -f alsa hw:1,7
๐๏ธ AudioToolbox
AudioToolbox output device.
Allows native output to CoreAudio devices on OSX ๐
The output filename can be empty (or -) to refer to the default system output device or a number that refers to the device index as shown using: -list_devices true.
Alternatively, the audio input device can be chosen by index using -audio_device_index <INDEX>, overriding any device name or index given in the input filename.
All available devices can be enumerated by using -list_devices true, listing all device names, UIDs and corresponding indices.
Options
AudioToolbox supports the following options:
-audio_device_index <INDEX>โ specify the audio device by its index. Overrides anything given in the output filename.
Examples
- Print the list of supported devices and output a sine wave to the default device:
$ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -list_devices true -
- Output a sine wave to the device with the index
2, overriding any output filename:
$ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -audio_device_index 2 -
๐ฆ caca
CACA output device.
This output device allows one to show a video stream in a CACA window. Only one CACA window is allowed per application, so you can have only one instance of this output device in an application ๐ญ
To enable this output device you need to configure FFmpeg with --enable-libcaca. libcaca is a graphics library that outputs text instead of pixels.
For more information about libcaca, check: http://caca.zoy.org/wiki/libcaca
Options
window_titleโ set the CACA window title, if not specified default to the filename specified for the output device.window_sizeโ set the CACA window size, can be a string of the formwidthxheightor a video size abbreviation. If not specified it defaults to the size of the input video.driverโ set display driver.algorithmโ set dithering algorithm. Dithering is necessary because the picture being rendered has usually far more colours than the available palette. The accepted values are listed with-list_dither algorithms.antialiasโ set antialias method. Antialiasing smoothens the rendered image and avoids the commonly seen staircase effect. The accepted values are listed with-list_dither antialiases.charsetโ set which characters are going to be used when rendering text. The accepted values are listed with-list_dither charsets.colorโ set color to be used when rendering text. The accepted values are listed with-list_dither colors.list_driversโ if set to true, print a list of available drivers and exit.list_ditherโ list available dither options related to the argument. The argument must be one ofalgorithms,antialiases,charsets,colors.
Examples
- The following command shows the ffmpeg output is an CACA window, forcing its size to
80x25:
ffmpeg -i INPUT -c:v rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -
- Show the list of available drivers and exit:
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -
- Show the list of available dither colors and exit:
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -
๐ฌ decklink
The decklink output device provides playback capabilities for Blackmagic DeckLink devices.
To enable this output device, you need the Blackmagic DeckLink SDK and you need to configure with the appropriate --extra-cflags and --extra-ldflags. On Windows, you need to run the IDL files through widl.
DeckLink is very picky about the formats it supports. Pixel format is always uyvy422, framerate, field order and video size must be determined for your device with -list_formats 1. Audio sample rate is always 48 kHz ๐ค
Options
list_devicesโ if set to true, print a list of devices and exit. Defaults to false. This option is deprecated, please use the-sinksoption of ffmpeg to list the available output devices.list_formatsโ if set to true, print a list of supported formats and exit. Defaults to false.prerollโ amount of time to preroll video in seconds. Defaults to0.5.duplex_modeโ sets the decklink device duplex/profile mode. Must beunset,half,full,one_sub_device_full,one_sub_device_half,two_sub_device_full,four_sub_device_half. Defaults tounset.
Note: DeckLink SDK 11.0 have replaced the duplex property by a profile property. For the DeckLink Duo 2 and DeckLink Quad 2, a profile is shared between any 2 sub-devices that utilize the same connectors. For the DeckLink 8K Pro, a profile is shared between all 4 sub-devices. So DeckLink 8K Pro support four profiles.
Valid profile modes for DeckLink 8K Pro (with DeckLink SDK >= 11.0): one_sub_device_full, one_sub_device_half, two_sub_device_full, four_sub_device_half
Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2: half, full
timing_offsetโ sets the genlock timing pixel offset on the used output. Defaults to unset.linkโ sets the SDI video link configuration on the used output. Must beunset,single link SDI,dual link SDIorquad link SDI. Defaults to unset.sqdโ enable Square Division Quad Split mode for Quad-link SDI output. Must beunset,trueorfalse. Defaults to unset.level_aโ enable SMPTE Level A mode on the used output. Must beunset,trueorfalse. Defaults to unset.vanc_queue_sizeโ sets maximum output buffer size in bytes for VANC data. If the buffering reaches this value, outgoing VANC data will be dropped. Defaults to1048576.
Examples
- List output devices:
ffmpeg -sinks decklink
- List supported formats:
ffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor'
- Play video clip:
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor'
- Play video clip with non-standard framerate or video size:
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 -s 720x486 -r 24000/1001 'DeckLink Mini Monitor'
๐ฅ๏ธ fbdev
Linux framebuffer output device.
The Linux framebuffer is a graphic hardware-independent abstraction layer to show graphics on a computer monitor, typically on the console. It is accessed through a file device node, usually /dev/fb0.
For more detailed information read the file Documentation/fb/framebuffer.txt included in the Linux source tree.
Options
xoffset,yoffsetโ set x/y coordinate of top left corner. Default is0.
Examples
Play a file on framebuffer device /dev/fb0. Required pixel format depends on current framebuffer settings.
ffmpeg -re -i INPUT -c:v rawvideo -pix_fmt bgra -f fbdev /dev/fb0
See also http://linux-fbdev.sourceforge.net/, and fbset(1).
๐ oss
OSS (Open Sound System) output device.
๐ซง pulse
PulseAudio output device.
To enable this output device you need to configure FFmpeg with --enable-libpulse.
More information about PulseAudio can be found on http://www.pulseaudio.org
Options
serverโ points you at a specific PulseAudio server, given by an IP address. Don't pass it? You get the default server, easy peasy ๐ซถnameโ the application name PulseAudio will show off when it's listing active clients. Default is the"LIBAVFORMAT_IDENT"string, iykyk.stream_nameโ the name PulseAudio uses when showing active streams. By default it's just set to whatever output name you specified. cute.deviceโ the device you actually wanna use. Leave it out and the default device gets picked. Wanna see your options? Pull up the list of output devices withpactl list sinks๐buffer_size,buffer_durationโ these two control the size and the duration of the PulseAudio buffer. Small buffer = more control but you're gonna be updating way more often, high maintenance queen energy fr.
buffer_size is the size in bytes, while buffer_duration is the duration in milliseconds.
Give it both and the highest value wins (the duration gets recalculated into bytes using the stream parameters, math is mathing โจ). Set them to 0 โ which is the default, btw โ and the device will just use the default PulseAudio duration value. By default PulseAudio sets buffer duration to around 2 seconds.
prebufโ pre-buffering size in bytes. The server will NOT start playback until at leastprebufbytes are sitting in the buffer, no exceptions bestie. By default this option initializes to the same value asbuffer_sizeorbuffer_duration, whichever is bigger.minreqโ minimum request size, in bytes. The server never requests less thanminreqbytes from the client โ instead it waits until the buffer is free enough to request more bytes all at once. Lowkey recommended that you don't set this one at all; leave it and it initializes to a value the server itself deems sensible ๐
โจ Examples โจ
Play a file on the default device on the default server:
ffmpeg -i INPUT -f pulse "stream name"
๐ sndio ๐
sndio audio output device. that's it, that's the whole vibe ๐ฆ
๐ v4l2 ๐
Video4Linux2 output device. iconic behavior.
๐ xv ๐
XV (XVideo) output device.
This output device is the one that lets you show a video stream in a X Window System window. very main character of it ๐
Options
display_nameโ the hardware display name, which decides the display and communications domain being used.
The display name โ or the DISPLAY environment variable โ can be a string in the format hostname[:number[.screen_number]].
hostname is the name of the host machine the display is physically attached to. number is the number of the display server on that host machine. screen_number is the screen to be used on that server.
Leave it unspecified and it defaults to the value of the DISPLAY environment variable.
For example, "dual-headed:0.1" would specify screen 1 of display 0 on the machine named ``dual-headed''.
Check the X11 specification for the full detailed tea on the display name format ๐
window_idโ set it to a non-zero value and the device won't create a new window at all, it'll use the existing one with thewindow_idyou provided. By default this option is0and the device creates its own window. independent queen.window_sizeโ sets the size of the created window. Can be a string of the formwidthxheightor a video size abbreviation. Not specified? It defaults to the size of the input video. Ignored whenwindow_idis set ๐window_x,window_yโ set the X and Y window offsets for the created window. They're both0by default. Fair warning: the window manager may just ignore these values, it does what it wants. Also ignored whenwindow_idis set.window_titleโ sets the window title. Not specified? Defaults to the filename you specified for the output device. Ignored whenwindow_idis set.
For more info about XVideo, go peek at http://www.x.org/ โญ
โจ Examples โจ
- Decode, display and encode video input with
ffmpegall at the same time, multitasking legend:
ffmpeg -i INPUT OUTPUT -f xv display
- Decode and display the input video into multiple X11 windows, because one window is never enough:
ffmpeg -i INPUT -f xv normal -vf negate -f xv negated
๐ธ RESAMPLER OPTIONS ๐ธ
okay so the audio resampler has all these named options and honestly it's giving "customization queen" ๐ here's the whole menu, bestie:
You can set these by passing -option value in the FFmpeg tools, or option=value for the aresample filter, or by setting the value directly in the SwrContext options, or with the libavutil/opt.h API if you're doing that programmatic thing โจ
uchl,used_chlayoutโ sets the used input channel layout. Default is unset, and ngl this one is only used for special remapping ๐isr,in_sample_rateโ sets the input sample rate. Default is0.osr,out_sample_rateโ sets the output sample rate. Default is0.isf,in_sample_fmtโ specifies the input sample format. Defaults tonone๐ฆosf,out_sample_fmtโ specifies the output sample format. Also defaults tonone.tsf,internal_sample_fmtโ sets the internal sample format. Default isnone, and if you don't set it explicitly it just gets chosen automatically for you. main character energy, it picks itself ๐ichl,in_chlayoutandochl,out_chlayoutโ set the input/output channel layout fr. Peep the Channel Layout section in theffmpeg-utils(1)manual for the syntax you need to use.clev,center_mix_levelโ center mix level, a value in deciBel that must be in the interval[-32,32].slev,surround_mix_levelโ surround mix level, also in deciBel, also gotta be in[-32,32].lfe_mix_levelโ sets LFE mix into non-LFE level. It kicks in when you've got an LFE input but no LFE output. deciBel again, and yes, interval[-32,32]๐ซถrmvol,rematrix_volumeโ sets rematrix volume. Default value is1.0.rematrix_maxvalโ maximum output value for rematrixing. Use this to pick between preventing clipping vs. preventing volume reduction. A value of1.0prevents clipping ๐flags,swr_flagsโ the flags the converter uses. Default value is0. Supports this individual flag:resโ force resampling. This one makes resampling happen even when the input and output sample rates match, no cap.
dither_scaleโ sets the dither scale. Default value is1.dither_methodโ sets the dither method. Default value is0. Supported values:rectangularโ select rectangular dithertriangularโ select triangular dithertriangular_hpโ select triangular dither with high passlipshitzโ select Lipshitz noise shaping dithershibataโ select Shibata noise shaping ditherlow_shibataโ select low Shibata noise shaping ditherhigh_shibataโ select high Shibata noise shaping ditherf_weightedโ select f-weighted noise shaping dithermodified_e_weightedโ select modified-e-weighted noise shaping ditherimproved_e_weightedโ select improved-e-weighted noise shaping dither
resamplerโ sets the resampling engine. Default value isswr. Supported values:swrโ select the native SW Resampler. heads up: the filter optionsprecisionandchebyare not applicable in this case.soxrโ select the SoX Resampler (where available). Also heads up:compensation, and the filter optionsfilter_size,phase_shift,exact_rational,filter_type&kaiser_beta, are not applicable in this case.
filter_sizeโ forswronly, sets the resampling filter size. Default value is32.phase_shiftโ forswronly, sets the resampling phase shift. Default value is10, and it must be in the interval[0,30].linear_interpโ use linear interpolation when enabled (that's the default, btw). Disable it if you'd rather preserve speed than quality whenexact_rationalfails ๐โโ๏ธexact_rationalโ forswronly. When enabled, it tries to use exactphase_countbased on the input and output sample rate. But if that ends up larger than1 << phase_shift, thenphase_countfalls back to1 << phase_shift. Default is enabled.cutoffโ sets the cutoff frequency ratio (swr: 6dB point;soxr: 0dB point). Must be a float between0and1. Default is0.97withswr, and0.91withsoxr(which, at a sample rate of44100, preserves the entire audio band to20kHz๐).precisionโ forsoxronly. The precision in bits that the resampled signal gets calculated to. The default20(which, with suitable dithering, is appropriate for a destination bit-depth of16) gives SoX's 'High Quality'; a value of28gives SoX's 'Very High Quality' โญchebyโ forsoxronly. Selects passband rolloff none (Chebyshev) & higher-precision approximation for 'irrational' ratios. Default value is0.asyncโ forswronly. Simple 1-parameter audio sync to timestamps using stretching, squeezing, filling and trimming. Setting it to1enables filling and trimming, and bigger values represent the max amount in samples the data may be stretched or squeezed for each second. Default value is0, so no compensation is applied to make the samples match the audio timestamps.first_ptsโ forswronly. Assume the first pts should be this value. Time unit is1 / sample rate. This lets you pad/trim at the start of the stream. By default no assumption is made about the first frame's expected pts, so no padding or trimming happens. Like, you could set this to0to pad the beginning with silence if an audio stream starts after the video stream, or to trim any samples with a negative pts caused by encoder delay ๐min_compโ forswronly. Sets the minimum difference between timestamps and audio data (in seconds) needed to trigger stretching/squeezing/filling or trimming so the data matches the timestamps. The default is that stretching/squeezing/filling and trimming is disabled (min_comp=FLT_MAX).min_hard_compโ forswronly. Sets the minimum difference between timestamps and audio data (in seconds) needed to trigger adding/dropping samples so it matches the timestamps. This is basically a threshold that picks between hard (trim/fill) and soft (squeeze/stretch) compensation. Note that all compensation is disabled by default throughmin_comp. The default here is0.1.comp_durationโ forswronly. Sets the duration (in seconds) over which data gets stretched/squeezed to match the timestamps. Must be a non-negative double float value, default value is1.0.max_soft_compโ forswronly. Sets the maximum factor by which data gets stretched/squeezed to match the timestamps. Must be a non-negative double float value, default value is0.matrix_encodingโ selects matrixed stereo encoding. Accepts these values:noneโ select nonedolbyโ select Dolbydpliiโ select Dolby Pro Logic II
Default value is none.
filter_typeโ forswronly. Selects the resampling filter type. This only affects resampling operations, bestie. Accepts:cubicโ select cubicblackman_nuttallโ select Blackman Nuttall windowed sinckaiserโ select Kaiser windowed sinc
kaiser_betaโ forswronly. Sets the Kaiser window beta value. Must be a double float value in the interval[2,16], default value is9.output_sample_bitsโ forswronly. Sets the number of used output sample bits for dithering. Must be an integer in the interval[0,64], default value is0, which means it's not used. slay ๐
๐ธ SCALER OPTIONS ๐ธ
Okay bestie, so the video scaler has its own little collection of named options and they're actually kind of a lot. Let's get into it ๐
You can set these by writing -option value in the FFmpeg tools โ with a couple of API-only exceptions that I'll flag below, don't worry. And if you're doing the programmatic thing? They can be set explicitly in the "SwsContext" options or through the libavutil/opt.h API. iykyk โจ
sws_flagsโ sets the scaler flags, and it's also what you use to pick the scaling algorithm. Important: only a single algorithm should be selected, no mixing and matching ๐ Default value isbicubic.
It accepts the following values:
fast_bilinearโ selects the fast bilinear scaling algorithm.bilinearโ selects the bilinear scaling algorithm.bicubicโ selects the bicubic scaling algorithm.experimentalโ selects the experimental scaling algorithm.neighborโ selects the nearest neighbor rescaling algorithm.areaโ selects the averaging area rescaling algorithm.bicublinโ selects the bicubic scaling algorithm for the luma component, and bilinear for the chroma components.gaussโ selects the Gaussian rescaling algorithm.sincโ selects the sinc rescaling algorithm.lanczosโ selects the Lanczos rescaling algorithm. The default width (alpha) is3and it can be changed by setting"param0". slay ๐ฅsplineโ selects the natural bicubic spline rescaling algorithm.print_infoโ enables printing/debug logging.accurate_rndโ enables accurate rounding.full_chroma_intโ enables full chroma interpolation.full_chroma_inpโ selects full chroma input.bitexactโ enables bitexact output.unstableโ allows the use of experimental new code. Heads up bestie, this may subtly affect the output or even produce wrong results. For testing only, fr fr ๐
srcw(API only) โ set source width.srch(API only) โ set source height.dstw(API only) โ set destination width.dsth(API only) โ set destination height.src_format(API only) โ set source pixel format (must be expressed as an integer).dst_format(API only) โ set destination pixel format (must be expressed as an integer).src_range(boolean) โ if the value is set to1, it indicates the source is full range. Default value is0, which indicates the source is limited range.dst_range(boolean) โ if the value is set to1, enable full range for the destination. Default value is0, which enables limited range.gamma(boolean) โ if the value is set to1, enable gamma correct scaling. Default value is0.param0,param1โ set scaling algorithm parameters. The values you give are specific to some scaling algorithms and just straight up ignored by others ๐ The specified values are floating point number values.sws_ditherโ set the dithering algorithm. Accepts one of the following values. Default value isauto.autoโ automatic choicenoneโ no ditheringbayerโ bayer ditheredโ error diffusion dithera_ditherโ arithmetic dither, based using additionx_ditherโ arithmetic dither, based using xor (more random/less apparent patterning thana_dither). lowkey iconic ๐ฆ
alphablendโ set the alpha blending to use when the input has alpha but the output does not. Default value isnone.uniform_colorโ blend onto a uniform background colorcheckerboardโ blend onto a checkerboardnoneโ no blending
โจ FILTERING INTRODUCTION โจ
Filtering in FFmpeg is enabled through the libavfilter library. Periodt. ๐
So in libavfilter, a filter can have multiple inputs and multiple outputs โ main character energy honestly. To illustrate the sorts of things that are possible, consider the following filtergraph:
[main]
input --> split ---------------------> overlay --> output
| ^
|[tmp] [flip]|
+-----> crop --> vflip -------+
This filtergraph splits the input stream into two streams, then sends one stream through the crop filter and the vflip filter, before merging it back with the other stream by overlaying it on top. You can use this command to achieve it:
ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
The result? The top half of the video gets mirrored onto the bottom half of the output video. like, literally the coolest thing ๐ญ๐
Filters in the same linear chain are separated by commas, and distinct linear chains of filters are separated by semicolons. In our example, crop,vflip are in one linear chain, and split and overlay are separately in another. The points where the linear chains join are labelled by names enclosed in square brackets. In the example, the split filter generates two outputs that are associated to the labels [main] and [tmp].
The stream sent to the second output of split, labelled as [tmp], is processed through the crop filter, which crops away the lower half part of the video, and then vertically flipped. The overlay filter takes in input the first unchanged output of the split filter (which was labelled as [main]), and overlays on its lower half the output generated by the crop,vflip filterchain.
Some filters take in input a list of parameters: they're specified after the filter name and an equal sign, and are separated from each other by a colon.
And just so you know, there exist so-called source filters that do not have an audio/video input, and sink filters that will not have audio/video output. ๐ซถ
๐ GRAPH ๐
The graph2dot program included in the FFmpeg tools directory can be used to parse a filtergraph description and issue a corresponding textual representation in the dot language. ngl that's kind of a flex ๐
Invoke the command:
graph2dot -h
to see how to use graph2dot.
You can then pass the dot description to the dot program (from the graphviz suite of programs) and obtain a graphical representation of the filtergraph. obsessed honestly ๐ฆโจ
For example, the sequence of commands:
echo <GRAPH_DESCRIPTION> | \
tools/graph2dot -o graph.tmp && \
dot -Tpng graph.tmp -o graph.png && \
display graph.png
can be used to create and display an image representing the graph described by the GRAPH_DESCRIPTION string. Note that this string must be a complete self-contained graph, with its inputs and outputs explicitly defined. For example, if your command line is of the form:
ffmpeg -i infile -vf scale=640:360 outfile
your GRAPH_DESCRIPTION string will need to be of the form:
nullsrc,scale=640:360,nullsink
you may also need to set the nullsrc parameters and add a format filter in order to simulate a specific input file. sneaky but necessary ๐๐
๐ FILTERGRAPH DESCRIPTION ๐
okay so bestie, a filtergraph is literally a directed graph of connected filters. and yeah โ it can contain cycles, and there can be multiple links between a pair of filters. no cap. ๐
each link has one input pad on one side connecting it to one filter from which it takes its input, and one output pad on the other side connecting it to one filter accepting its output. that's the whole vibe. ๐ซถ
each filter in a filtergraph is an instance of a filter class registered in the application, and that class is what defines the features and the number of input and output pads of the filter. ๐
and the terminology, because we love vocabulary:
- a filter with no input pads is called a "source" โจ
- a filter with no output pads is called a "sink" ๐ณ๏ธ
โจ Filtergraph syntax โจ
a filtergraph has a textual representation, and it's recognized by the -filter/-vf/-af and -filter_complex options in ffmpeg and -vf/-af in ffplay, and by the avfilter_graph_parse_ptr() function defined in libavfilter/avfilter.h. iykyk. ๐
a filterchain consists of a sequence of connected filters, each one connected to the previous one in the sequence. a filterchain is represented by a list of ","-separated filter descriptions.
a filtergraph consists of a sequence of filterchains. a sequence of filterchains is represented by a list of ";"-separated filterchain descriptions. ๐
a filter is represented by a string of the form:
[in_link_1]...[in_link_N]filter_name@id=arguments[out_link_1]...[out_link_M]
filter_name is the name of the filter class of which the described filter is an instance of, and has to be the name of one of the filter classes registered in the program, optionally followed by @id. the name of the filter class is optionally followed by a string =arguments. ๐ธ
arguments is a string which contains the parameters used to initialize the filter instance. the manpage says it "may have one of two forms" and then lists three bullets โ and honestly? we stan a generous queen. here they are:
- A
':'-separated list ofkey=valuepairs. ๐ - A
':'-separated list ofvalue. in this case, the keys are assumed to be the option names in the order they are declared. E.g. the"fade"filter declares three options in this order --type,start_frameandnb_frames. then the parameter listin:0:30means that the valueinis assigned to the optiontype,0tostart_frameand30tonb_frames. ๐ฅ - A
':'-separated list of mixed directvalueand longkey=valuepairs. the direct value must precede thekey=valuepairs, and follow the same constraints order of the previous point. the followingkey=valuepairs can be set in any preferred order. ๐
if the option value itself is a list of items (e.g. the "format" filter takes a list of pixel formats), the items in the list are usually separated by |. โญ
the list of arguments can be quoted using the character ' as initial and ending mark, and the character \ for escaping the characters within the quoted text; otherwise the argument string is considered terminated when the next special character (belonging to the set []=;,) is encountered. lowkey important, highkey useful. ๐ฆ
a special syntax implemented in the ffmpeg CLI tool allows loading option values from files. this is done by prepending a slash / to the option name, then the supplied value is interpreted as a path from which the actual value is loaded. E.g.
ffmpeg -i <INPUT> -vf drawtext=/text=/tmp/some_text <OUTPUT>
will load the text to be drawn from /tmp/some_text. API users wishing to implement a similar feature should use the "avfilter_graph_segment_*()" functions together with custom IO code. ๐ง
the name and arguments of the filter are optionally preceded and followed by a list of link labels. a link label allows one to name a link and associate it to a filter output or input pad. the preceding labels in_link_1 ... in_link_N are associated to the filter input pads, the following labels out_link_1 ... out_link_M are associated to the output pads. ๐
when two link labels with the same name are found in the filtergraph, a link between the corresponding input and output pad is created. match made in heaven, honestly. ๐
if an output pad is not labelled, it is linked by default to the first unlabelled input pad of the next filter in the filterchain. for example in the filterchain
nullsrc, split[L1], [L2]overlay, nullsink
the split filter instance has two output pads, and the overlay filter instance two input pads. the first output pad of split is labelled "L1", the first input pad of overlay is labelled "L2", and the second output pad of split is linked to the second input pad of overlay, which are both unlabelled. slay. โจ
in a filter description, if the input label of the first filter is not specified, "in" is assumed; if the output label of the last filter is not specified, "out" is assumed. defaults are free, bestie. ๐
in a complete filterchain all the unlabelled filter input and output pads must be connected. a filtergraph is considered valid if all the filter input and output pads of all the filterchains are connected. no loose ends, periodt. ๐
leading and trailing whitespaces (space, tabs, or line feeds) separating tokens in the filtergraph specification are ignored. this means that the filtergraph can be expressed using empty lines and spaces to improve readability. we love a formatting moment. ๐ธ
for example, the filtergraph:
testsrc,split[L1],hflip[L2];[L1][L2] hstack
can be represented as:
testsrc,
split [L1], hflip [L2];
[L1][L2] hstack
Libavfilter will automatically insert scale filters where format conversion is required. it is possible to specify swscale flags for those automatically inserted scalers by prepending "sws_flags=flags;" to the filtergraph description. ๐ฆ
here is a BNF description of the filtergraph syntax:
<NAME> ::= sequence of alphanumeric characters and '_'
<FILTER_NAME> ::= <NAME>["@"<NAME>]
<LINKLABEL> ::= "[" <NAME> "]"
<LINKLABELS> ::= <LINKLABEL> [<LINKLABELS>]
<FILTER_ARGUMENTS> ::= sequence of chars (possibly quoted)
<FILTER> ::= [<LINKLABELS>] <FILTER_NAME> ["=" <FILTER_ARGUMENTS>] [<LINKLABELS>]
<FILTERCHAIN> ::= <FILTER> [,<FILTERCHAIN>]
<FILTERGRAPH> ::= [sws_flags=<flags>;] <FILTERCHAIN> [;<FILTERGRAPH>]
๐ Notes on filtergraph escaping ๐
filtergraph description composition entails several levels of escaping. see the "Quoting and escaping" section in the ffmpeg-utils(1) manual for more information about the employed escaping procedure. ๐ญ
a first level escaping affects the content of each filter option value, which may contain the special character ":" used to separate values, or one of the escaping characters "\'".
a second level escaping affects the whole filter description, which may contain the escaping characters "\'" or the special characters "[],;" used by the filtergraph description.
finally, when you specify a filtergraph on a shell commandline, you need to perform a third level escaping for the shell special characters contained within it. three levels deep, bestie. we're in inception. ๐
for example, consider the following string to be embedded in the drawtext filter description text value:
this is a 'string': may contain one, or more, special characters
this string contains the "'" special escaping character, and the ":" special character, so it needs to be escaped in this way:
text=this is a \'string\'\: may contain one, or more, special characters
a second level of escaping is required when embedding the filter description in a filtergraph description, in order to escape all the filtergraph special characters. thus the example above becomes:
drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
(note that in addition to the "\'" escaping special characters, also "," needs to be escaped). ๐
finally an additional level of escaping is needed when writing the filtergraph description in a shell command, which depends on the escaping rules of the adopted shell. for example, assuming that "\" is special and needs to be escaped with another "\", the previous string will finally result in:
-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
in order to avoid cumbersome escaping when using a commandline tool accepting a filter specification as input, it is advisable to avoid direct inclusion of the filter or options specification in the shell. ๐ซถ
for example, in case of the drawtext filter, you might prefer to use the textfile option in place of text to specify the text to render. so much cleaner, honestly. โจ
โฐ TIMELINE EDITING โฐ
some filters support a generic enable option. for the filters supporting timeline editing, this option can be set to an expression which is evaluated before sending a frame to the filter. if the evaluation is non-zero, the filter will be enabled, otherwise the frame will be sent unchanged to the next filter in the filtergraph. main character filter behavior. ๐
the expression accepts the following values:
tโ timestamp expressed in seconds,NANif the input timestamp is unknown ๐nโ sequential number of the input frame, starting from0๐ขposโ the position in the file of the input frame,NANif unknown; deprecated, do not use ๐whโ width and height of the input frame if video ๐
additionally, these filters support an enable command that can be used to re-define the expression. ๐ฅ
like any other filtering option, the enable option follows the same rules. ๐
for example, to enable a blur filter (smartblur) from 10 seconds to 3 minutes, and a curves filter starting at 3 seconds:
smartblur = enable='between(t,10,3*60)',
curves = enable='gte(t,3)' : preset=cross_process
see "ffmpeg -filters" to view which filters have timeline support. go check it, bestie, it's giving homework but make it cute. ๐
๐๏ธ CHANGING OPTIONS AT RUNTIME WITH A COMMAND ๐๏ธ
some options can be changed during the operation of the filter using a command. these options are marked 'T' on the output of ffmpeg -h filter=<name of filter>. the name of the command is the name of the option and the argument is the new value. live tweaking, we love to see it. ๐
โจ
โจ OPTIONS FOR FILTERS WITH SEVERAL INPUTS โจ
Okay so some filters have multiple inputs and they all share a lil common set of options, bestie. Important vibe check though: these can only be set by name โ the short notation does not work here, periodt.
eof_actionโ what to do when the secondary input hits EOF; it accepts one of these values:repeatโ repeat the last frame (this is the default, she's the main character ๐).endallโ end both streams. everyone goes home.passโ pass the main input through. keep it movin' ๐
shortestโ if set to1, force the output to terminate when the shortest input terminates. Default value is0.repeatlastโ if set to1, force the filter to extend the last frame of secondary streams until the end of the primary stream. A value of0disables this behavior. Default value is1.ts_sync_modeโ how strictly to sync streams based on secondary input timestamps; it accepts one of the following values:defaultโ frame from secondary input with the nearest lower or equal timestamp to the primary input frame.nearestโ frame from secondary input with the absolute nearest timestamp to the primary input frame.
๐ธ AUDIO FILTERS ๐ธ
When you configure your FFmpeg build, you can disable any of the existing filters using --disable-filters. The configure output will show the audio filters included in your build โ so you always know what you're working with ๐.
Below is a description of the currently available audio filters. Buckle up, there's a lot.
๐ aap
Apply Affine Projection algorithm to the first audio stream using the second audio stream.
This adaptive filter is used to estimate unknown audio based on multiple input audio samples. Affine projection algorithm can make trade-offs between computation complexity with convergence speed โ it's giving "choose your fighter" energy ngl.
A description of the accepted options follows.
orderโ set the filter order.projectionโ set the projection order.muโ set the filter mu.deltaโ set the coefficient to initialize internal covariance matrix.out_modeโ set the filter output samples. It accepts the following values:iโ pass the 1st input.dโ pass the 2nd input.oโ pass difference between desired, 2nd input and error signal estimate.nโ pass difference between input, 1st input and error signal estimate.eโ pass error signal estimated samples.
Default value is o.
precisionโ set which precision to use when processing samples.autoโ auto pick internal sample format depending on other filters.floatโ always use single-floating point precision sample format.doubleโ always use double-floating point precision sample format.
๐ฅ acompressor
A compressor is mainly used to reduce the dynamic range of a signal. Especially modern music is mostly compressed at a high ratio to improve the overall loudness. It's done to get the highest attention of a listener, "fatten" the sound and bring more "power" to the track. If a signal is compressed too much it may sound dull or "dead" afterwards or it may start to "pump" (which could be a powerful effect but can also destroy a track completely). The right compression is the key to reach a professional sound and is the high art of mixing and mastering. Because of its complex settings it may take a long time to get the right feeling for this kind of effect โ it's an art form fr fr ๐ญ.
Compression is done by detecting the volume above a chosen level "threshold" and dividing it by the factor set with "ratio". So if you set the threshold to -12dB and your signal reaches -6dB a ratio of 2:1 will result in a signal at -9dB. Because an exact manipulation of the signal would cause distortion of the waveform the reduction can be levelled over the time. This is done by setting "Attack" and "Release". "attack" determines how long the signal has to rise above the threshold before any reduction will occur and "release" sets the time the signal has to fall below the threshold to reduce the reduction again. Shorter signals than the chosen attack time will be left untouched. The overall reduction of the signal can be made up afterwards with the "makeup" setting. So compressing the peaks of a signal about 6dB and raising the makeup to this level results in a signal twice as loud than the source. To gain a softer entry in the compression the "knee" flattens the hard edge at the threshold in the range of the chosen decibels โ chef's kiss ๐
The filter accepts the following options:
level_inโ set input gain. Default is1. Range is between0.015625and64.modeโ set mode of compressor operation. Can beupwardordownward. Default isdownward.thresholdโ if a signal of stream rises above this level it will affect the gain reduction. By default it is0.125. Range is between0.00097563and1.ratioโ set a ratio by which the signal is reduced.1:2means that if the level rose4dBabove the threshold, it will be only2dBabove after the reduction. Default is2. Range is between1and20.attackโ amount of milliseconds the signal has to rise above the threshold before gain reduction starts. Default is20. Range is between0.01and2000.releaseโ amount of milliseconds the signal has to fall below the threshold before reduction is decreased again. Default is250. Range is between0.01and9000.makeupโ set the amount by how much signal will be amplified after processing. Default is1. Range is from1to64.kneeโ curve the sharp knee around the threshold to enter gain reduction more softly. Default is2.82843. Range is between1and8.linkโ choose if the "average" level between all channels of input stream or the louder ("maximum") channel of input stream affects the reduction. Default isaverage.detectionโ should the exact signal be taken in case ofpeakor an RMS one in case ofrms. Default isrmswhich is mostly smoother.mixโ how much to use compressed signal in output. Default is1. Range is between0and1.
๐ Commands
This filter supports the all above options as commands. yes bestie, live tweaking, we love to see it โจ
๐ฆ acontrast
Simple audio dynamic range compression/expansion filter.
The filter accepts the following options:
contrastโ set contrast. Default is33. Allowed range is between0and100.
โญ acopy
Copy the input audio source unchanged to the output. This is mainly useful for testing purposes. literally just vibes, passing it through untouched ๐
๐ acrossfade
Apply cross fade from one input audio stream to another input audio stream. The cross fade is applied for specified duration near the end of first stream.
The filter accepts the following options:
inputs,nโ specify the number of inputs to crossfade. When crossfading multiple inputs, each input will be concatenated and crossfaded in sequence, similar to theconcatfilter. Default is2.nb_samples,nsโ specify the number of samples for which the cross fade effect has to last. At the end of the cross fade effect the first input audio will be completely silent. Default is44100.duration,dโ specify the duration of the cross fade effect. See the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. By default the duration is determined bynb_samples. If set this option is used instead ofnb_samples.overlap,oโ should first stream end overlap with second stream start. Default is enabled.curve1โ set curve for cross fade transition for first stream.curve2โ set curve for cross fade transition for second stream.
For description of available curve types see afade filter description.
๐ Examples
- Cross fade from one input to another:
ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:c1=exp:c2=exp output.flac
- Cross fade from one input to another but without overlapping:
ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:o=0:c1=exp:c2=exp output.flac
Concatenate multiple inputs with cross fade between each:
ffmpeg -i first.flac -i second.flac -i third.flac -filter_complex acrossfade=n=3 output.flac
๐ง acrossover
Split audio stream into several bands.
This filter splits audio stream into two or more frequency ranges. Summing all streams back will give flat output โ she's balanced, she's iconic ๐.
The filter accepts the following options:
splitโ set split frequencies. Those must be positive and increasing. no chaotic energy allowed, keep it ascending bestie ๐orderโ set filter order for each band split. This controls filter roll-off or steepness of filter transfer function. Available values are:2ndโ 12 dB per octave.4thโ 24 dB per octave.6thโ 36 dB per octave.8thโ 48 dB per octave.10thโ 60 dB per octave.12thโ 72 dB per octave.14thโ 84 dB per octave.16thโ 96 dB per octave.18thโ 108 dB per octave.20thโ 120 dB per octave.
Default is 4th.
levelโ set input gain level. Allowed range is from0to1. Default value is1.gainsโ set output gain for each band. Default value is1for all bands.precisionโ set which precision to use when processing samples.autoโ auto pick internal sample format depending on other filters.floatโ always use single-floating point precision sample format.doubleโ always use double-floating point precision sample format.
Default value is auto.
๐ธ Examples
- Split input audio stream into two bands (low and high) with split frequency of
1500 Hz, each band will be in separate stream:
ffmpeg -i in.flac -filter_complex 'acrossover=split=1500[LOW][HIGH]' -map '[LOW]' low.wav -map '[HIGH]' high.wav
- Same as above, but with higher filter order:
ffmpeg -i in.flac -filter_complex 'acrossover=split=1500:order=8th[LOW][HIGH]' -map '[LOW]' low.wav -map '[HIGH]' high.wav
- Same as above, but also with additional middle band (frequencies between
1500and8000):
ffmpeg -i in.flac -filter_complex 'acrossover=split=1500 8000:order=8th[LOW][MID][HIGH]' -map '[LOW]' low.wav -map '[MID]' mid.wav -map '[HIGH]' high.wav
๐ acrusher
Reduce audio bit resolution.
okay so this filter is a bit crusher but make it โจenhanced functionalityโจ. if you don't know, a bit crusher audibly reduces the number of bits your audio signal gets sampled with โ and no, it does not touch the actual bit depth at all, it just produces the effect. and the effect? material with reduced bit depth sounds harsher and way more "digital", which is honestly the whole point ๐ .
but bestie this one is extra: it can even round to continuous values instead of discrete bit depths. plus it's got a D/C offset, so the lower half and upper half of the signal get crushed differently. and there's an Anti-Aliasing setting that gives you "softer" crushing sounds ๐.
another feature: the logarithmic mode. this switches from linear distances between bits to logarithmic ones. the result is a much more "natural" sounding crusher that, for example, doesn't gate low signals. the human ear perceives logarithmically, so this kind of crushing is so much more pleasant. and yes, logarithmic crushing can get anti-aliased too ๐ฆ.
the filter accepts these options:
level_inโ set the level going in.level_outโ set the level coming out.bitsโ set the bit reduction.mixโ set the mixing amount.modeโ can be linear:"lin"or logarithmic:"log".dcโ set the DC.aaโ set the anti-aliasing.samplesโ set the sample reduction.lfoโ enable the LFO. disabled by default.lforangeโ set the LFO range.lforateโ set the LFO rate.
๐ซ Commands
this filter supports all of the above options as commands, iykyk ๐ฅ.
๐ธ acue
delay audio filtering until a given wallclock timestamp. go look at the cue filter, it's the same vibe ๐ซถ.
๐ธ adeclick
removes impulsive noise from the input audio. samples that get detected as impulsive noise are replaced by interpolated samples using autoregressive modelling โจ.
window,wโ set the window size, in milliseconds. allowed range is10to100. default is55milliseconds. this sets the size of the window that gets processed at once.overlap,oโ set the window overlap, as a percentage of window size. allowed range is50to95. default is75percent. setting this super high increases impulsive noise removal but makes the whole process way slower ๐ญ.arorder,aโ set the autoregression order, as a percentage of window size. allowed range is0to25. default is2percent. this option also controls the quality of the interpolated samples using neighbouring good samples.threshold,tโ set the threshold value. allowed range is1to100. default is2. this controls the strength of the impulsive noise that's gonna get removed. lower value = more samples get detected as impulsive noise.burst,bโ set the burst fusion, as a percentage of window size. allowed range is0to10. default is2. if any two samples detected as noise are spaced less than this value, then any sample between those two also gets detected as noise ๐.method,mโ set the overlap method. it accepts:add,aโ select the overlap-add method. heads up: even the not-interpolated samples get slightly changed with this one.save,sโ select the overlap-save method. not-interpolated samples stay unchanged, iconique.
default value is "a".
๐ธ adeclip
removes clipped samples from the input audio. samples detected as clipped get replaced by interpolated samples using autoregressive modelling ๐.
window,wโ set the window size, in milliseconds. allowed range is10to100. default is55milliseconds. this sets the size of the window processed at once.overlap,oโ set the window overlap, as a percentage of window size. allowed range is50to95. default is75percent.arorder,aโ set the autoregression order, as a percentage of window size. allowed range is0to25. default is8percent. this also controls the quality of the interpolated samples using neighbouring good samples.threshold,tโ set the threshold value. allowed range is1to100. default is10. higher values make clip detection less aggressive.hsize,nโ set the size of the histogram used to detect clips. allowed range is100to9999. default is1000. higher values make clip detection less aggressive too.method,mโ set the overlap method. it accepts:add,aโ select the overlap-add method. even not-interpolated samples are slightly changed with this method.save,sโ select the overlap-save method. not-interpolated samples remain unchanged.
default value is "a".
๐ธ adecorrelate
applies decorrelation to the input audio stream ๐ฆ.
the filter accepts these options:
stagesโ set the decorrelation stages of filtering. allowed range is1to16. default is6.seedโ set the random seed used for setting the delay in samples across channels.
๐ธ adelay
delays one or more audio channels. samples in the delayed channel get filled with silence ๐คซ.
the filter accepts this option:
delaysโ set the list of delays in milliseconds for each channel, separated by'|'. unused delays get silently ignored (rude but okay). if the number of given delays is smaller than the number of channels, all the remaining channels just won't be delayed. want to delay an exact number of samples? append'S'to the number. want instead to delay in seconds? append's'to the number.allโ use the last set delay for all remaining channels. disabled by default. heads up: if you enable this, it changes how the"delays"option is interpreted ๐
โจ Examples
- delay the first channel by 1.5 seconds, the third channel by 0.5 seconds, and leave the second channel (and any other channels that may be present) unchanged.
adelay=1500|0|500
- delay the second channel by 500 samples, the third channel by 700 samples, and leave the first channel (and any other channels that may be present) unchanged.
adelay=0|500S|700S
- delay all channels by the same number of samples:
adelay=delays=64S:all=1
๐ธ adenorm
fixes denormals in your audio by adding extremely low-level noise ๐ง. this filter should be placed before any filter that can produce denormals.
here's the parameters it takes:
levelโ set the level of the added noise in dB. default is-351. allowed range is-451to-90.typeโ set the type of added noise:dcโ add a DC signal.acโ add an AC signal.squareโ add a square signal.pulseโ add a pulse signal.
default is "dc".
๐ซ Commands
this filter supports all of the above options as commands ๐ .
๐ธ aderivative, aintegral
compute the derivative/integral of an audio stream. fun fact: applying both filters one after another produces the original audio โ it's giving reversible, we love to see it ๐.
๐ธ adrc
applies the spectral dynamic range controller filter to the input audio stream ๐ฅ.
here's the options:
transferโ set the transfer expression. the expression can contain these constants:chโ current channel numbersnโ current sample numbernb_channelsโ number of channelstโ timestamp expressed in secondssrโ sample ratepโ current frequency power value, in dBfโ current frequency in Hz
default value is "p".
attackโ set the attack in milliseconds. default is50milliseconds. allowed range is1to1000milliseconds.releaseโ set the release in milliseconds. default is100milliseconds. allowed range is5to2000milliseconds.channelsโ set which channels to filter. by default"all"channels in the audio stream get filtered.
๐ซ Commands
this filter supports all of the above options as commands ๐ซถ.
โจ Examples
- apply spectral compression to all frequencies with a threshold of
-50dB and a 1:6 ratio:
adrc=transfer='if(gt(p,-50),-50+(p-(-50))/6,p)':attack=50:release=100
- similar to above, but with a 1:2 ratio and filtering only the front center channel:
adrc=transfer='if(gt(p,-50),-50+(p-(-50))/2,p)':attack=50:release=100:channels=FC
- apply a spectral noise gate to all frequencies with a threshold of
-85dB, with a short attack time and a short release time:
adrc=transfer='if(lte(p,-85),p-800,p)':attack=1:release=5
- apply spectral expansion to all frequencies with a threshold of
-10dB and a 1:2 ratio:
adrc=transfer='if(lt(p,-10),-10+(p-(-10))*2,p)':attack=50:release=100
- apply a limiter to max
-60dB to all frequencies, with an attack of2ms and a release of10ms:
adrc=transfer='min(p,-60)':attack=2:release=10
๐ธ adynamicequalizer
applies dynamic equalization to the input audio stream ๐.
here's the accepted options:
thresholdโ set the detection threshold used to trigger the equalization. the threshold detection is using the detection filter. default value is0. allowed range is0to100.dfrequencyโ set the detection frequency in Hz used for the detection filter that triggers the equalization. default value is1000Hz. allowed range is between2and1000000Hz.dqfactorโ set the detection resonance factor for the detection filter that triggers the equalization. default value is1. allowed range is0.001to1000.tfrequencyโ set the target frequency of the equalization filter. default value is1000Hz. allowed range is between2and1000000Hz.tqfactorโ set the target resonance factor for the target equalization filter. default value is1. allowed range is0.001to1000.attackโ set the amount of milliseconds the signal from detection has to rise above the detection threshold before equalization starts. default is20. allowed range is between1and2000.releaseโ set the amount of milliseconds the signal from detection has to fall below the detection threshold before equalization ends. default is200. allowed range is between1and2000.ratioโ set the ratio by which the equalization gain is raised. default is1. allowed range is between0and30.makeupโ set the makeup offset by which the equalization gain is raised. default is0. allowed range is between0and100.rangeโ set the max allowed cut/boost amount. default is50. allowed range is1to200.modeโ set the mode of filter operation. can be one of these:listenโ output only the isolated detection signal.
cutbelowโ chop out the frequencies that sit below the detection threshold ๐cutaboveโ chop out the ones above the detection thresholdboostbelowโ turn up everything below the thresholdboostaboveโ turn up everything above it
Default mode? cutbelow. That's the one it picks if you don't say anything.
dftype Set the type of detection filter, bestie. Pick one of these:
bandpasslowpasshighpasspeak
Default type is bandpass โจ
tftype Now the type of the target filter. Options are:
belllowshelfhighshelf
Default type is bell ๐
auto Automatically gather the threshold from the detection filter. Off by default. This one's lowkey iconic because it lets you detect the threshold in a certain time frame of the input audio stream โ and in that case the option value gets changed at runtime. Yes, it just changes itself. Main character behavior tbh.
Available values:
disabledโ don't use the automatically gathered threshold value.offโ stop picking the threshold value.onโ start picking the threshold value.adaptiveโ adaptively pick the threshold value, by calculating sliding window entropy. Fancy fr.
precision Which precision do we use when processing samples? Choose:
autoโ auto pick the internal sample format depending on other filters.floatโ always use single-floating point precision sample format.doubleโ always use double-floating point precision sample format.
Commands
This filter supports all the above options as commands ๐ซถ
๐ฆ adynamicsmooth
Apply dynamic smoothing to the input audio stream.
Here's the description of the accepted options, bestie:
sensitivity Sets how sensitive it is to frequency fluctations. Default is 2. Allowed range is from 0 to 1e+06.
basefreq Sets a base frequency for the smoothing. Default value is 22050. Allowed range is from 2 to 1e+06.
Commands
This filter supports all the above options as commands โจ
๐ธ aecho
Apply echoing to the input audio.
Okay so real talk: echoes are reflected sound, right? They happen naturally amongst mountains (and sometimes large buildings) when you're talking or shouting. Digital echo effects emulate that exact behaviour, and people use them all the time to help fill out the sound of a single instrument or vocal. The time difference between the original signal and the reflection is the "delay", and the loudness of the reflected signal is the "decay". Multiple echoes can have different delays and decays โ yes, multiple. Go off ๐
A description of the accepted parameters follows:
in_gainโ set input gain of reflected signal. Default is0.6.out_gainโ set output gain of reflected signal. Default is0.3.delaysโ set list of time intervals in milliseconds between original signal and reflections, separated by'|'. Allowed range for each "delay" is "(0 - 90000.0]". Default is1000.decaysโ set list of loudness of reflected signals, separated by'|'. Allowed range for each "decay" is "(0 - 1.0]". Default is0.5.
Examples
- Make it sound as if there are twice as many instruments as are actually playing:
aecho=0.8:0.88:60:0.4
- If delay is very short, then it sounds like a (metallic) robot playing music:
aecho=0.8:0.88:6:0.4
- A longer delay will sound like an open air concert in the mountains:
aecho=0.8:0.9:1000:0.3
- Same as above but with one more mountain:
aecho=0.8:0.9:1000|1800:0.3|0.25
๐ aemphasis
The audio emphasis filter creates โ or restores โ material taken directly from LPs or emphased CDs with different filter curves. Think about it: to store music on vinyl the signal has to be altered by a filter first, to even out the disadvantages of that recording medium. Then once the material is played back, the inverse filter has to be applied to restore the distortion of the frequency response. Symmetry, iconique.
The filter accepts the following options:
level_inโ set input gain.level_outโ set output gain.modeโ set filter mode. For restoring material use"reproduction"mode, otherwise use"production"mode. Default is"reproduction"mode.typeโ set filter type. Selects the medium. Can be one of the following:colโ select Columbia.emiโ select EMI.bsiโ select BSI (78RPM).riaaโ select RIAA.cdโ select Compact Disc (CD).50fmโ select 50ยตs (FM).75fmโ select 75ยตs (FM).50kfโ select 50ยตs (FM-KF).75kfโ select 75ยตs (FM-KF).
Commands
This filter supports all the above options as commands ๐
โญ aeval
Modify an audio signal according to the specified expressions.
This filter accepts one or more expressions (one for each channel), which get evaluated and used to modify a corresponding audio signal. So like, math but make it audio.
It accepts the following parameters:
exprs Set the '|'-separated expressions list for each separate channel. If the number of input channels is greater than the number of expressions, the last specified expression is used for the remaining output channels. Wrap-around queen ๐
channel_layout, c Set output channel layout. If not specified, the channel layout is specified by the number of expressions. If set to same, it will use by default the same input channel layout.
Each expression in exprs can contain the following constants and functions:
chโ channel number of the current expressionnโ number of the evaluated sample, starting from0sโ sample ratetโ time of the evaluated sample expressed in secondsnb_in_channels,nb_out_channelsโ input and output number of channelsval(CH)โ the value of input channel with number CH
Heads up bestie ๐ญ this filter is slow. For faster processing you should use a dedicated filter.
Examples
- Half volume:
aeval=val(ch)/2:c=same
- Invert phase of the second channel:
aeval=val(0)|-val(1)
๐ฅ aexciter
An exciter is used to produce high sound that is not present in the original signal. How? By creating harmonic distortions of the signal, which get restricted in range and added to the original signal. An exciter raises the upper end of an audio signal without simply raising the higher frequencies the way an equalizer would โ all so you get a more "crisp" or "brilliant" sound. It's giving glow-up for your audio โจ
The filter accepts the following options:
level_inโ set input level prior to processing of the signal. Allowed range is from0to64. Default value is1.level_outโ set output level after processing of the signal. Allowed range is from0to64. Default value is1.amountโ set the amount of harmonics added to the original signal. Allowed range is from0to64. Default value is1.driveโ set the amount of newly created harmonics. Allowed range is from0.1to10. Default value is8.5.blendโ set the octave of newly created harmonics. Allowed range is from-10to10. Default value is0.freqโ set the lower frequency limit of producing harmonics in Hz. Allowed range is from2000to12000Hz. Default is7500Hz.ceilโ set the upper frequency limit of producing harmonics. Allowed range is from9999to20000Hz. If the value is lower than10000Hz no limit is applied.listenโ mute the original signal and output only the added harmonics. By default is disabled.
Commands
This filter supports all the above options as commands ๐
๐ afade
Apply a fade-in/fade-out effect to the input audio.
A description of the accepted parameters follows:
type, t Specify the effect type โ either "in" for fade-in, or "out" for a fade-out effect. Default is "in".
start_sample, ss Specify the number of the start sample for starting to apply the fade effect. Default is 0.
nb_samples, ns Specify the number of samples for which the fade effect has to last. At the end of the fade-in effect the output audio will have the same volume as the input audio; at the end of the fade-out transition the output audio will be silence. Default is 44100.
start_time, st Specify the start time of the fade effect. Default is 0. The value must be specified as a time duration โ peep the Time duration section in the ffmpeg-utils(1) manual for the accepted syntax. If set, this option is used instead of start_sample.
duration, d Specify the duration of the fade effect. See the Time duration section in the ffmpeg-utils(1) manual for the accepted syntax. At the end of the fade-in effect the output audio will have the same volume as the input audio; at the end of the fade-out transition the output audio will be silence. By default the duration is determined by nb_samples. If set, this option is used instead of nb_samples.
curve Set the curve for the fade transition.
It accepts the following values:
triโ select triangular, linear slope (default)qsinโ select quarter of sine wavehsinโ select half of sine waveesinโ select exponential sine wavelogโ select logarithmiciparโ select inverted parabolaquaโ select quadraticcubโ select cubicsquโ select square rootcbrโ select cubic rootparโ select parabolaexpโ select exponentialiqsinโ select inverted quarter of sine waveihsinโ select inverted half of sine wavedeseโ select double-exponential seatdesiโ select double-exponential sigmoidlosiโ select logistic sigmoidsincโ select sine cardinal functionisincโ select inverted sine cardinal functionquatโ select quarticquatrโ select quartic rootqsin2โ select squared quarter of sine wavehsin2โ select squared half of sine wavenofadeโ no fade applied
silence Set the initial gain for fade-in or final gain for fade-out. Default value is 0.0.
unity Set the initial gain for fade-out or final gain for fade-in. Default value is 1.0.
Commands
This filter supports all the above options as commands ๐ฆ
Examples
- Fade in the first 15 seconds of audio:
afade=t=in:ss=0:d=15
- Fade out the last 25 seconds of a 900 seconds audio:
afade=t=out:st=875:d=25
๐ afftdn
Denoise audio samples with FFT.
A lil' rundown of every knob this filter takes โ read on bestie, it's all here ๐
noise_reduction,nrโ sets the noise reduction in dB. Allowed range is0.01to97. Default value is12dB.noise_floor,nfโ sets the noise floor in dB. Allowed range is-80to-20. Default value is-50dB.noise_type,ntโ picks which flavor of noise we're dealing with ๐
It accepts the following values:
white,wโ select white noise.vinyl,vโ select vinyl noise.shellac,sโ select shellac noise.custom,cโ select custom noise, defined in thebnoption.
Default value is white noise.
band_noise,bnโ sets a custom band noise profile for every one of 15 bands. Bands are separated by' 'or'|'.residual_floor,rfโ sets the residual floor in dB. Allowed range is-80to-20. Default value is-38dB.track_noise,tnโ enables noise floor tracking. By default it's disabled. Turn it on and the noise floor gets adjusted automatically, no cap โจtrack_residual,trโ enables residual tracking. By default it's disabled.output_mode,omโ sets the output mode.
It accepts the following values:
input,iโ pass input unchanged.output,oโ pass noise filtered out.noise,nโ pass only noise.
Default value is output.
adaptivity,adโ sets the adaptivity factor, i.e. how fast the gains adjustments adapt per each frequency bin. Value0enables instant adaptation, while higher values react much slower. Allowed range is from0to1. Default value is0.5.floor_offset,foโ sets the noise floor offset factor. This one adjusts the offset applied to the measured noise floor, and it's only effective when noise floor tracking is enabled. Allowed range is from-2.0to2.0. Default value is1.0.noise_link,nlโ sets the noise link used for multichannel audio.
It accepts the following values:
noneโ use unchanged channel's noise floor.minโ use measured min noise floor of all channels.maxโ use measured max noise floor of all channels.averageโ use measured average noise floor of all channels.
Default value is min.
band_multiplier,bmโ sets the band multiplier factor, which controls how much to spread bands across frequency bins. Allowed range is from0.2to5. Default value is1.25.sample_noise,snโ toggles capturing and measurement of the noise profile from the input audio, iykyk ๐ธ
It accepts the following values:
start,beginโ start sample noise capture.stop,endโ stop sample noise capture and measure new noise band profile.
Default value is "none".
gain_smooth,gsโ sets the gain smooth spatial radius, used to smooth the gains applied to each frequency bin. Super useful for reducing random music noise artefacts. Higher values increase the smoothing of gains. Allowed range is from0to50. Default value is0.
Commands ๐
This filter supports the some above mentioned options as commands.
Examples ๐
- Reduce white noise by 10dB, and use previously measured noise floor of -40dB:
afftdn=nr=10:nf=-40
- Reduce white noise by 10dB, also set initial noise floor to -80dB and enable automatic tracking of noise floor so the noise floor will gradually change during processing:
afftdn=nr=10:nf=-80:tn=1
- Reduce noise by 20dB, using noise floor of -40dB and using commands to take the noise profile of the first 0.4 seconds of input audio:
asendcmd=0.0 afftdn sn start,asendcmd=0.4 afftdn sn stop,afftdn=nr=20:nf=-40
afftfilt ๐ฆ
Apply arbitrary expressions to samples in the frequency domain. Yes, it's giving main character math energy, and we love her.
realโ set the frequency domain real expression for each separate channel, separated by'|'. Default is"re". If the number of input channels is greater than the number of expressions, the last specified expression is used for the remaining output channels.imagโ set the frequency domain imaginary expression for each separate channel, separated by'|'. Default is"im".
Each expression in real and imag can contain the following constants and functions:
srโ sample ratebโ current frequency bin numbernbโ number of available binschโ channel number of the current expressionchsโ number of channelsptsโ current frame ptsreโ current real part of frequency bin of current channelimโ current imaginary part of frequency bin of current channelreal(b, ch)โ return the value of the real part of the frequency bin at location (bin,channel)imag(b, ch)โ return the value of the imaginary part of the frequency bin at location (bin,channel)
win_sizeโ set window size. Allowed range is from16to131072. Default is4096win_funcโ set the window function.
It accepts the following values:
rectbartletthann,hanninghammingblackmanwelchflattopbharrisbnuttallbhannsinenuttalllanczosgausstukeydolphcauchyparzenpoissonbohmankaiser
Default is "hann".
overlapโ set window overlap. Set it to1and the recommended overlap for the selected window function gets picked for you, slay. Default is0.75.
Examples ๐
- Leave almost only low frequencies in the audio:
afftfilt="'real=re * (1-clip((b/nb)*b,0,1))':imag='im * (1-clip((b/nb)*b,0,1))'"
- Apply the robotize effect:
afftfilt="real='hypot(re,im)*sin(0)':imag='hypot(re,im)*cos(0)':win_size=512:overlap=0.75"
- Apply the whisper effect:
afftfilt="real='hypot(re,im)*cos((random(0)*2-1)*2*3.14)':imag='hypot(re,im)*sin((random(1)*2-1)*2*3.14)':win_size=128:overlap=0.8"
- Apply phase shift:
afftfilt="real=re*cos(1)-im*sin(1):imag=re*sin(1)+im*cos(1)"
afir ๐
Apply an arbitrary Finite Impulse Response filter.
This filter is designed for applying long FIR filters, up to 60 seconds long.
It can be used as a component for digital crossover filters, room equalization, cross talk cancellation, wavefield synthesis, auralization, ambiophonics, ambisonics and spatialization. Literally the moment fr fr ๐
This filter uses the streams higher than the first one as FIR coefficients. If the non-first stream holds a single channel, it'll be used for all input channels in the first stream โ otherwise the number of channels in the non-first stream must be the same as the number of channels in the first stream.
It accepts the following parameters:
dryโ set dry gain. This sets input gain.wetโ set wet gain. This sets final output gain.lengthโ set Impulse Response filter length. Default is1, which means the whole IR is processed.gtypeโ this option is deprecated, and does nothing. ๐irnormโ set norm to be applied to IR coefficients before filtering. Allowed range is from-1to2. IR coefficients are normalized with the calculated vector norm set by this option. For negative values, no norm is calculated, and IR coefficients are not modified at all. Default is1.irlinkโ for multichannel IR, if this option is set to true, all IR channels will be normalized with the maximal measured gain of all IR channels coefficients as set by theirnormoption. When disabled, all IR coefficients in each IR channel get normalized independently. Default istrue.irgainโ set gain to be applied to IR coefficients before filtering. Allowed range is0to1. This gain is applied after any gain applied with theirnormoption.irfmtโ set format of IR stream. Can be"mono"or"input". Default is"input".maxirโ set max allowed Impulse Response filter duration in seconds. Default is30seconds. Allowed range is0.1to60seconds.responseโ this option is deprecated, and does nothing.channelโ this option is deprecated, and does nothing.sizeโ this option is deprecated, and does nothing.rateโ this option is deprecated, and does nothing.minpโ set minimal partition size used for convolution. Default is8192. Allowed range is from1to65536. Lower values decrease latency at the cost of higher CPU usage.maxpโ set maximal partition size used for convolution. Default is8192. Allowed range is from8to65536. Lower values may increase CPU usage.nbirsโ set number of input impulse response streams which will be switchable at runtime. Allowed range is from1to32. Default is1.irโ set the IR stream which will be used for convolution, starting from0; should always be lower than the value supplied by thenbirsoption. Default is0. This option can be changed at runtime via commands.precisionโ set which precision to use when processing samples.autoโ auto pick internal sample format depending on other filters.floatโ always use single-floating point precision sample format.doubleโ always use double-floating point precision sample format.
Default value is auto.
irloadโ set when to load the IR stream. Can be"init"or"access". The first one loads and prepares all IRs on initialization, the second one loads once on first access of a specific IR. Default is"init".
Examples โจ
- Apply reverb to a stream using a mono IR file as second input, complete command using
ffmpeg:
ffmpeg -i input.wav -i middle_tunnel_1way_mono.wav -lavfi afir output.wav
- Apply true stereo processing given an input stereo stream, and two stereo impulse responses for left and right channel โ the impulse response files are files with names
l_ir.wavandr_ir.wavโ and set theirnormoption value:
"pan=4C|c0=FL|c1=FL|c2=FR|c3=FR[a];amovie=l_ir.wav[LIR];amovie=r_ir.wav[RIR];[LIR][RIR]amerge[ir];[a][ir]afir=irfmt=input:irnorm=1.2,pan=stereo|FL<c0+c2|FR<c1+c3"
- Similar to the above example, but with
irgainexplicitly set to the estimated value and withirnormdisabled:
"pan=4C|c0=FL|c1=FL|c2=FR|c3=FR[a];amovie=l_ir.wav[LIR];amovie=r_ir.wav[RIR];[LIR][RIR]amerge[ir];[a][ir]afir=irfmt=input:irgain=-5dB:irnom=-1,pan=stereo|FL<c0+c2|FR<c1+c3"
aformat ๐ธ
Set output format constraints for the input audio. The framework will negotiate the most appropriate format to minimize conversions. She's a problem solver, your honor ๐ซถ
It accepts the following parameters:
sample_fmts,fโ a|-separated list of the sample formats you're begging for.sample_rates,rโ a|-separated list of requested sample rates. same deal, just vibes in Hz.channel_layouts,clโ a|-separated list of channel layouts you want. the syntax lives in the Channel Layout section of theffmpeg-utils(1)manual, go peek ๐
If a parameter is omitted, all values are allowed. generous queen behavior honestly ๐
Wanna force the output to either unsigned 8-bit or signed 16-bit stereo? say less:
aformat=sample_fmts=u8|s16:channel_layouts=stereo
afreqshift
Apply a frequency shift to input audio samples. ngl it's giving "I moved the whole spectrum to the left" energy โจ
The filter accepts the following options:
shiftโ specify the frequency shift. allowed range is-INT_MAXtoINT_MAX. default value is0.0.levelโ set the output gain applied to the final output. allowed range is from0.0to1.0. default value is1.0.orderโ set the filter order used for filtering. allowed range is from1to16. default value is8.
Commands
This filter supports the all above options as commands. yes, all of them, live, mid-stream, chaotic but iconic ๐
afwtdn
Reduce broadband noise from your input samples using Wavelets. it's the "bestie your mic is hissing" filter fr fr ๐ง
A description of the accepted options follows.
sigmaโ set the noise sigma, allowed range is from0to1. default value is0. this option controls the strength of denoising applied to input samples. most useful way to set this option is via decibels, eg.-45dB.levelsโ set the number of wavelet levels of decomposition. allowed range is from1to12. default is10. setting this too low makes denoising performance very poor โ like, embarrassing levels of poor ๐ญwavetโ set the wavelet type for decomposition of the input frame. they're sorted by number of coefficients, from lowest to highest. more coefficients means worse filtering speed, but overall better quality. available wavelets are:sym2sym4rbior68deb10sym10coif5bl3
percentโ set the percent of full denoising. allowed range is from0to100percent. default value is85percent, aka partial denoising.profileโ if enabled, the first input frame will be used as the noise profile. if first frame samples contain non-noise, performance will be very poor. so like, don't feed it your actual song and call it noise, babe ๐adaptiveโ if enabled, input frames are analyzed for presence of noise. if noise is detected with high possibility, then the input frame profile will be used for processing following frames, until a new noise frame is detected. it learns. main character energy.samplesโ set the size of a single frame in number of samples. allowed range is from512to65536. default frame size is8192samples.softnessโ set the softness applied inside the thresholding function. allowed range is from0to10. default softness is1.commandsโ wait no, that's a heading, see below lol
Commands
This filter supports the all above options as commands. periodt ๐
agate
A gate is mainly used to reduce the lower parts of a signal. this kind of signal processing reduces disturbing noise between useful signals โ it's literally the "shhh not right now" of audio ๐ซถ
Gating is done by detecting the volume below a chosen level threshold and dividing it by the factor set with ratio. the bottom of the noise floor is set via range. because an exact manipulation of the signal would cause distortion of the waveform, the reduction can be levelled over time. this is done by setting attack and release.
attack determines how long the signal has to fall below the threshold before any reduction will occur, and release sets the time the signal has to rise above the threshold to reduce the reduction again. shorter signals than the chosen attack time will be left untouched. untouched, bestie. we don't touch โจ
level_inโ set the input level before filtering. default is1. allowed range is from0.015625to64.modeโ set the mode of operation. can be"upward"or"downward". default is"downward". if set to"upward"mode, higher parts of the signal will be amplified, expanding dynamic range in the upward direction. otherwise, in the case of"downward", lower parts of the signal will be reduced.rangeโ set the level of gain reduction when the signal is below the threshold. default is0.06125. allowed range is from0to1. setting this to0disables reduction, and then the filter behaves like an expander.thresholdโ if a signal rises above this level the gain reduction is released. default is0.125. allowed range is from0to1.ratioโ set a ratio by which the signal is reduced. default is2. allowed range is from1to9000. that's a lot of ratio, ngl.attackโ amount of milliseconds the signal has to rise above the threshold before gain reduction stops. default is20milliseconds. allowed range is from0.01to9000.releaseโ amount of milliseconds the signal has to fall below the threshold before the reduction is increased again. default is250milliseconds. allowed range is from0.01to9000.makeupโ set the amount of amplification of the signal after processing. default is1. allowed range is from1to64.kneeโ curve the sharp knee around the threshold to enter gain reduction more softly. default is2.828427125. allowed range is from1to8.detectionโ choose if the exact signal should be taken for detection or an RMS-like one. default is"rms". can be"peak"or"rms".linkโ choose if the average level between all channels or the louder channel affects the reduction. default is"average". can be"average"or"maximum".
Commands
This filter supports the all above options as commands. all of them. go off ๐
aiir
Apply an arbitrary Infinite Impulse Response filter. arbitrary!! you get to design the whole thing yourself, that's so much power honestly ๐
It accepts the following parameters:
zeros,zโ set B/numerator/zeros/reflection coefficients.poles,pโ set A/denominator/poles/ladder coefficients.gains,kโ set channels gains.dry_gainโ set input gain.wet_gainโ set output gain.format,fโ set coefficients format.llโ lattice-ladder functionsfโ analog transfer functiontfโ digital transfer functionzpโ Z-plane zeros/poles, cartesian (default)prโ Z-plane zeros/poles, polar radianspdโ Z-plane zeros/poles, polar degreesspโ S-plane zeros/poles
process,rโ set type of processing.dโ direct processingsโ serial processingpโ parallel processing
precision,eโ set filtering precision.dblโ double-precision floating-point (default)fltโ single-precision floating-pointi32โ 32-bit integersi16โ 16-bit integers
normalize,nโ normalize filter coefficients, by default is enabled. enabling it will normalize the magnitude response at DC to0dB.mixโ how much to use the filtered signal in the output. default is1. range is between0and1.responseโ show IR frequency response, magnitude (magenta), phase (green) and group delay (yellow) in an additional video stream. by default it is disabled. cute little graphs, obsessed ๐channelโ set for which IR channel to display frequency response. by default the first channel is displayed. this option is used only whenresponseis enabled.sizeโ set video stream size. this option is used only whenresponseis enabled.
Coefficients in "tf" and "sf" format are separated by spaces and are in ascending order.
Coefficients in "zp" format are separated by spaces and the order of coefficients doesn't matter. coefficients in "zp" format are complex numbers with i imaginary unit.
Different coefficients and gains can be provided for every channel, in which case use '|' to separate coefficients or gains. the last provided coefficients will be used for all remaining channels. slay, the rest just inherit ๐
Examples
- Apply a 2 pole elliptic notch at around
5000Hzfor48000 Hzsample rate:
aiir=k=1:z=7.957584807809675810E-1 -2.575128568908332300 3.674839853930788710 -2.57512875289799137 7.957586296317130880E-1:p=1 -2.86950072432325953 3.63022088054647218 -2.28075678147272232 6.361362326477423500E-1:f=tf:r=d
- Same as above but in
"zp"format:
aiir=k=0.79575848078096756:z=0.80918701+0.58773007i 0.80918701-0.58773007i 0.80884700+0.58784055i 0.80884700-0.58784055i:p=0.63892345+0.59951235i 0.63892345-0.59951235i 0.79582691+0.44198673i 0.79582691-0.44198673i:f=zp:r=s
- Apply a 3-rd order analog normalized Butterworth low-pass filter, using analog transfer function format:
aiir=z=1.3057 0 0 0:p=1.3057 2.3892 2.1860 1:f=sf:r=d
alimiter
The limiter prevents an input signal from rising over a desired threshold. this limiter uses lookahead technology to prevent your signal from distorting. what that means is there's a small delay after the signal is processed โ keep in mind that the delay it produces is the attack time you set. so like, it's not free, it costs you a lil latency ๐ญ
The filter accepts the following options:
level_inโ set input gain. default is1.level_outโ set output gain. default is1.limitโ don't let signals above this level pass the limiter. default is1.attackโ the limiter will reach its attenuation level in this amount of time in milliseconds. default is5milliseconds.releaseโ come back from limiting to attenuation1.0in this amount of milliseconds. default is50milliseconds.ascโ when gain reduction is always needed, ASC takes care of releasing to an average reduction level rather than reaching a reduction of0in the release time.asc_levelโ select how much the release time is affected by ASC,0means nearly no changes in release time while1produces higher release times.levelโ auto level output signal. default is enabled. this normalizes audio back to0dBif enabled.latencyโ compensate the delay introduced by using the lookahead buffer set with theattackparameter. also flush the valid audio data in the lookahead buffer when the stream hitsEOF.
Depending on the picked setting it is recommended to upsample the input 2x or 4x times with aresample before applying this filter. do it, bestie, your future self will thank you ๐ธ
allpass
Apply a two-pole all-pass filter with central frequency (in Hz) frequency, and filter-width width. an all-pass filter changes the audio's frequency-to-phase relationship without changing its frequency-to-amplitude relationship. it's literally passing through but making everything โจfancierโจ
The filter accepts the following options:
frequency,fโ set frequency in Hz.width_type,tโ set method to specify band-width of filter.hโ Hzqโ Q-Factoroโ octavesโ slopekโ kHz
width,wโ specify the band-width of a filter inwidth_typeunits.mix,mโ how much to use the filtered signal in the output. default is1. range is between0and1.
okay so, back to the knob buffet โ these are giving control freak in the best way:
channels,cโ tell it which channels to filter; if you donโt, all available channels get filtered, periodt.normalize,nโ normalizes biquad coefficients. Default is disabled. Turn it on and it normalizes the magnitude response at DC to0dBโจ.order,oโ sets the filter order. It can be1or2. Default is2.transform,aโ sets the transform type of the IIR filter, bestie. The options are:didiitditdiilattsvfzdf
precision,rโ sets the precision of filtering:autoโ pick automatic sample format depending on surround filters.s16โ always use signed 16-bit.s32โ always use signed 32-bit.f32โ always use float 32-bit.f64โ always use float 64-bit.
๐๏ธ Commands ๐๏ธ
this filter is command-enabled, and it supports the following commands:
frequency,fโ change allpass frequency. Syntax for the command is :"frequency"๐width_type,tโ change allpass width_type. Syntax for the command is :"width_type"width,wโ change allpass width. Syntax for the command is :"width"mix,mโ change allpass mix. Syntax for the command is :"mix"
๐ aloop
Loop audio samples. Thatโs literally the whole vibe.
The filter accepts the following options:
loopโ set the number of loops. Setting this value to-1will result in infinite loops. Default is0.sizeโ set maximal number of samples. Default is0.startโ set first sample of loop. Default is0.timeโ set the time of loop start in seconds. Only used if the option namedstartis set to-1.
๐ธ amerge
Merge two or more audio streams into a single multi-channel stream. slay, but with rules:
All inputs must have the same sample rate, and format.
If inputs do not have the same duration, the output will stop with the shortest one.
The filter accepts the following options:
inputsโ set the number of inputs. Default is2.layout_modeโ this option controls how the output channel layout is determined and if the audio channels are reordered during merge. The modes are:legacyโ this is the mode how the filter behaved historically, so it is the default. If the channel layouts of the inputs are known and disjoint, and therefore compatible, the channel layout of the output will be set accordingly and the channels will be reordered as necessary. If the channel layouts of the inputs are not disjoint, some of them are unknown, or they are using special channel layouts, such as ambisonics, the output will have all the channels of the first input then all the channels of the second input, in that order, and the channel layout of the output will be the default value corresponding to the total number of channels.- Example time: if the first input is in
2.1(FL+FR+LF) and the second input isFC+BL+BR, then the output will be in5.1, with the channels in the following order:a1, a2, b1, a3, b2, b3(a1is the first channel of the first input,b1is the first channel of the second input). - On the other hand, if both inputs are in stereo, the output channels will be in the default order:
a1, a2, b1, b2, and the channel layout will be arbitrarily set to4.0, which may or may not be the expected value. iykyk.
- Example time: if the first input is in
resetโ this mode ignores the input channel layouts and does no channel reordering. The output will have all the channels of the first input, then all the channels of the second input, in that order, and so on. The output channel layout will only specify the total channel count.normalโ this mode keeps channel name and designation information from the input channels and does no channel reordering. The output will have all the channels of the first input, then all the channels of the second input, in that order, and so on.
โจ Examples โจ
- Merge two mono files into a stereo stream:
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
- Multiple merges assuming 1 video stream and 6 audio streams in
input.mkv:
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
๐ amix
Mixes multiple audio inputs into a single output. Itโs giving group project, but it actually works.
Note that this filter only supports float samples (the amerge and pan audio filters support many formats). If the amix input has integer samples then aresample will be automatically inserted to perform the conversion to float samples. no cap.
It accepts the following parameters:
inputsโ the number of inputs. If unspecified, it defaults to2.durationโ how to determine the end-of-stream:longestโ the duration of the longest input. This is the default.shortestโ the duration of the shortest input.firstโ the duration of the first input.
dropout_transitionโ the transition time, in seconds, for volume renormalization when an input stream ends. The default value is2seconds.weightsโ specify weight of each input audio stream as a sequence of numbers separated by a space. If fewer weights are specified compared to number of inputs, the last weight is assigned to the remaining inputs. Default weight for each input is1.normalizeโ always scale inputs instead of only doing summation of samples. Beware of heavy clipping if inputs are not normalized prior or after filtering by this filter if this option is disabled. By default it is enabled.
โจ Examples โจ
- This will mix 3 input audio streams to a single output with the same duration as the first input and a dropout transition time of 3 seconds:
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
- This will mix one vocal and one music input audio stream to a single output with the same duration as the longest input. The music will have quarter the weight as the vocals, and the inputs are not normalized:
ffmpeg -i VOCALS -i MUSIC -filter_complex amix=inputs=2:duration=longest:dropout_transition=0:weights="1 0.25":normalize=0 OUTPUT
๐๏ธ Commands ๐๏ธ
this filter supports the following commands:
weightsnormalize
Syntax is same as the option with the same name. copy-paste energy, honestly.
โจ amultiply
Multiply first audio stream with second audio stream and store result in output audio stream. Multiplication is done by multiplying each sample from first stream with sample at same position from second stream.
With this element-wise multiplication one can create amplitude fades and amplitude modulations. math but make it cute ๐ฆ.
๐ anequalizer
High-order parametric multiband equalizer for each channel. Itโs giving main character EQ.
It accepts the following parameters:
paramsโ this option string is in format:"cchn f=cf w=w g=g t=f | ..."Each equalizer band is separated by'|'.chnโ set channel number to which equalization will be applied. If input doesnโt have that channel the entry is ignored.fโ set central frequency for band. If input doesnโt have that frequency the entry is ignored.wโ set band width in Hertz.gโ set band gain in dB.tโ set filter type for band, optional, can be:0โ Butterworth, this is default.1โ Chebyshev type 1.2โ Chebyshev type 2.
curvesโ with this option activated, frequency response ofanequalizeris displayed in video stream.sizeโ set video stream size. Only useful ifcurvesoption is activated.mgainโ set max gain that will be displayed. Only useful ifcurvesoption is activated. Setting this to a reasonable value makes it possible to display gain which is derived from neighbour bands which are too close to each other and thus produce higher gain when both are activated.fscaleโ set frequency scale used to draw frequency response in video output. Can belinearorlogarithmic. Default islogarithmic.colorsโ set color for each channel curve which is going to be displayed in video stream. This is list of color names separated by space or by'|'. Unrecognised or missing colors will be replaced by white color.
โจ Example โจ
- Lower gain by 10 of central frequency
200Hzand width100 Hzfor first 2 channels using Chebyshev type 1 filter:
anequalizer=c0 f=200 w=100 g=-10 t=1|c1 f=200 w=100 g=-10 t=1
๐๏ธ Commands ๐๏ธ
this filter supports the following commands:
changeโ alter existing filter parameters. Syntax for the commands is :"fN|f=freq|w=width|g=gain"fNis existing filter number, starting from0; if no such filter is available, error is returned.freqset new frequency parameter.widthset new width parameter in Hertz.gainset new gain parameter in dB.- Full filter invocation with
asendcmdmay look like this:
asendcmd=c='4.0 anequalizer change 0|f=200|w=50|g=1',anequalizer=...
๐ฆ anlmdn
Reduce broadband noise in audio samples using Non-Local Means algorithm. science bestie behavior.
Each sample is adjusted by looking for other samples with similar contexts. This context similarity is defined by comparing their surrounding patches of size p. Patches are searched in an area of r around the sample.
The filter accepts the following options:
strength,sโ set denoising strength. Allowed range is from0.00001to10000. Default value is0.00001.patch,pโ set patch radius duration. Allowed range is from1to100milliseconds. Default value is2milliseconds.research,rโ set research radius duration. Allowed range is from2to300milliseconds. Default value is6milliseconds.output,oโ set the output mode. It accepts the following values:iโ pass input unchanged.oโ pass noise filtered out.nโ pass only noise.
Default value is o.
smooth,mโ set smooth factor. Default value is11. Allowed range is from1to1000.
๐๏ธ Commands ๐๏ธ
this filter supports the all above options as commands. yes, all of them ๐ .
๐ง anlmf, anlms
Apply Normalized Least-Mean-(Squares|Fourth) algorithm to the first audio stream using the second audio stream. Itโs giving adaptive filter era.
This adaptive filter is used to mimic a desired filter by finding the filter coefficients that relate to producing the least mean square of the error signal (difference between the desired, 2nd input audio stream and the actual signal, the 1st input audio stream).
A description of the accepted options follows:
orderโ set filter order.muโ set filtermu.epsโ sets the filtereps, bestie. That's the whole vibe. โจleakageโ sets the filterleakage. also justโฆ that. ๐ซถout_modeโ picks which samples actually make it out the door. accepted values are:iโ passes the 1st input through. ๐dโ passes the 2nd input through.oโ passes the difference between the desired signal, the 2nd input, and the error signal estimate.nโ passes the difference between the input, the 1st input, and the error signal estimate.eโ passes the error signal estimated samples.
the default is o, no cap. ๐
precisionโ sets which precision to use when processing samples:autoโ auto picks the internal sample format depending on the other filters. lowkey the flexible icon.floatโ always uses single-floating point precision sample format.doubleโ always uses double-floating point precision sample format. highkey the overachiever. ๐
๐ธ Examples ๐ธ
- one of the many usages of this filter is noise reduction โ your input audio gets filtered with the same samples, just delayed by a fixed amount. here's one such example for stereo audio, and yes it's giving main character energy:
asplit[a][b],[a]adelay=32S|32S[a],[b][a]anlms=order=128:leakage=0.0005:mu=.5:out_mode=o
๐ Commands ๐
this filter supports the same commands as options โ with the one exception of the option "order". so close, and yet. ๐
๐ anull ๐
passes the audio source unchanged to the output. literally does nothing and we respect that. queen of minding her own business. โญ
๐ฆ apad ๐ฆ
pads the end of an audio stream with silence. ๐ธ
this can be used together with ffmpeg -shortest to extend audio streams to the same length as the video stream. matching lengths is the whole point, iykyk. ๐
here's a description of the accepted options, bestie:
packet_sizeโ sets the silence packet size. default value is4096. ๐ฆpad_lenโ sets the number of samples of silence to add to the end. once that value is reached, the stream is terminated. this option is mutually exclusive withwhole_lenโ it's one or the other, periodt.whole_lenโ sets the minimum total number of samples in the output audio stream. if the value is longer than the input audio length, silence gets added to the end until the value is reached. this option is mutually exclusive withpad_len. ๐ซถpad_durโ specifies the duration of samples of silence to add. check the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. used only if set to a non-negative value. โณwhole_durโ specifies the minimum total duration in the output audio stream. same deal โ see the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. used only if set to a non-negative value. if the value is longer than the input audio length, silence is added to the end until the value is reached. this option is mutually exclusive withpad_dur. ๐
if neither thepad_lennor thewhole_lennorpad_durnorwhole_duroption is set, the filter will add silence to the end of the input stream indefinitely. not me warning you that it literally never stops ๐ญ
note that forffmpeg4.4 and earlier, a zeropad_durorwhole_duralso caused the filter to add silence indefinitely. old-version behavior, she's got lore. ๐
๐ Examples ๐
- add
1024samples of silence to the end of the input:
apad=pad_len=1024
- make sure the audio output will contain at least
10000samples, padding the input with silence if required:
apad=whole_len=10000
- use
ffmpegto pad the audio input with silence, so that the video stream will always result the shortest and will be converted until the end in the output file when using the shortest option:
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
๐ง aphaser ๐ง
adds a phasing effect to the input audio. ๐ฅ
a phaser filter creates a series of peaks and troughs in the frequency spectrum. the position of the peaks and troughs gets modulated so they vary over time โ which creates a sweeping effect. it's giving โจmovementโจ.
a description of the accepted parameters follows:
in_gainโ sets input gain. default is0.4.out_gainโ sets output gain. default is0.74.delayโ sets delay in milliseconds. default is3.0.decayโ sets decay. default is0.4.speedโ sets modulation speed in Hz. default is0.5.typeโ sets modulation type. default istriangular. it accepts the following values:triangular,tsinusoidal,s
๐ aphaseshift ๐
applies phase shift to input audio samples. ๐
the filter accepts the following options:
shiftโ specifies phase shift. allowed range is from-1.0to1.0. default value is0.0.levelโ sets the output gain applied to the final output. allowed range is from0.0to1.0. default value is1.0.orderโ sets the filter order used for filtering. allowed range is from1to16. default value is8. ๐
๐ Commands ๐
this filter supports all above options as commands. every single one, slay. ๐
๐ apsnr ๐
measures Audio Peak Signal-to-Noise Ratio. ๐
this filter takes two audio streams for input, and outputs the first audio stream. results are in dB per channel at the end of either input. that's it, that's the filter. ๐
โญ apsyclip โญ
applies a Psychoacoustic clipper to the input audio stream. yes, psychoacoustic. we're fancy now. ๐ง
the filter accepts the following options:
level_inโ sets input gain. by default it is1. range is[0.015625 - 64].level_outโ sets output gain. by default it is1. range is[0.015625 - 64].clipโ sets the clipping start value. default value is0dBFSor1. ๐๏ธdiffโ outputs only difference samples, useful to hear introduced distortions. by default it's disabled.adaptiveโ sets the strength of adaptive distortion applied. default value is0.5. allowed range is from0to1.iterationsโ sets the number of iterations of the psychoacoustic clipper. allowed range is from1to20. default value is10. ๐levelโ auto levels the output signal. default is disabled. this normalizes audio back to0dBFSif enabled. ๐
๐ Commands ๐
this filter supports all above options as commands. periodt.
๐ธ apulsator ๐ธ
Audio pulsator is something between an autopanner and a tremolo. but it can produce funny stereo effects as well, bestie. ๐ซ
Pulsator changes the volume of the left and right channel based on a LFO (low frequency oscillator) with different waveforms and shifted phases. this filter has the ability to define an offset between left and right channel.
an offset of 0 means both LFO shapes match each other exactly โ the left and right channel are altered equally, which is a conventional tremolo.
an offset of 50% means the shape of the right channel is exactly shifted in phase (or moved backwards about half of the frequency) โ and now pulsator acts as an autopanner.
at 1 both curves match again. every setting in between moves the phase shift gaplessly between all the stages and produces some "bypassing" sounds with sine and triangle waveforms. the more you set the offset near 1 (starting from the 0.5), the faster the signal passes from the left to the right speaker. ๐ฅ
the filter accepts the following options:
level_inโ sets input gain. by default it is1. range is[0.015625 - 64].level_outโ sets output gain. by default it is1. range is[0.015625 - 64].modeโ sets the waveform shape the LFO will use. can be one of:sine,triangle,square,sawuporsawdown. default issine. ๐amountโ sets modulation. defines how much of the original signal is affected by the LFO.offset_lโ sets left channel offset. default is0. allowed range is[0 - 1].offset_rโ sets right channel offset. default is0.5. allowed range is[0 - 1].widthโ sets pulse width. default is1. allowed range is[0 - 2].timingโ sets the possible timing mode. can be one of:bpm,msorhz. default ishz. โฑ๏ธbpmโ sets bpm. default is120. allowed range is[30 - 300]. only used iftimingis set tobpm.msโ sets ms. default is500. allowed range is[10 - 2000]. only used iftimingis set toms.hzโ sets frequency in Hz. default is2. allowed range is[0.01 - 100]. only used iftimingis set tohz.
๐ซถ aresample ๐ซถ
resamples the input audio to the specified parameters, using the libswresample library. if none are specified, then the filter will automatically convert between its input and output. she's flexible like that. ๐
this filter is also able to stretch/squeeze the audio data to make it match the timestamps, or to inject silence / cut out audio to make it match the timestamps, do a combination of both, or do neither. the range of options is honestly iconic. โจ
the filter accepts the syntax [sample_rate:]resampler_options, where sample_rate expresses a sample rate and resampler_options is a list of key=value pairs, separated by ":". see the "Resampler Options" section in the ffmpeg-resampler(1) manual for the complete list of supported options. ๐
๐ Examples ๐
- resample the input audio to
44100Hz:
aresample=44100
- stretch/squeeze samples to the given timestamps, with a maximum of
1000samples per second compensation:
aresample=async=1000
๐ areverse ๐
reverses an audio clip. ๐
Warning: this filter requires memory to buffer the entire clip, so trimming is suggested. like, please trim first, bestie, your RAM is not infinite ๐ญ
๐ Examples ๐
- take the first 5 seconds of a clip, and reverse it:
atrim=end=5,areverse
๐ฆ arls ๐ฆ
applies the Recursive Least Squares algorithm to the first audio stream using the second audio stream. ๐งฎ
this adaptive filter is used to mimic a desired filter by recursively finding the filter coefficients that relate to producing the minimal weighted linear least squares cost function of the error signal โ that's the difference between the desired, 2nd input audio stream and the actual signal, the 1st input audio stream. yes that's a lot of words, but every one of them matters. ๐
a description of the accepted options follows:
orderโ sets the filter order.lambdaโ sets the forgetting factor.deltaโ sets the coefficient to initialize the internal covariance matrix.out_modeโ sets the filter output samples. it accepts the following values:iโ passes the 1st input.dโ passes the 2nd input.oโ passes the difference between the desired, 2nd input and the error signal estimate.nโ passes the difference between the input, 1st input and the error signal estimate.eโ passes the error signal estimated samples.
default value is o. ๐
precisionโ sets which precision to use when processing samples:autoโ auto picks the internal sample format depending on other filters.floatโ always uses single-floating point precision sample format.doubleโ always uses double-floating point precision sample format. ๐
๐ arnndn ๐
reduces noise from speech using Recurrent Neural Networks. ๐คโจ literally AI in your audio pipeline, we love to see it.
this filter accepts the following options:
model,mโ sets the train model file to load. this option is always required. no model, no filter, no exceptions, bestie. ๐จmixโ set how much of the filtered samples gets mixed into the final output, bestie. Allowed range is -1 to 1, and the default is 1. Negative values are the special little guys ๐ซถ โ they set how much of the filtered noise stays in the final filter output. Set this option to-1if you literally want to hear the actual noise that got removed from the input signal.
Commands
This filter supports the all above options as commands โจ.
asdr
Measure Audio Signal-to-Distortion Ratio ๐ .
This filter takes two audio streams for input, and outputs the first audio stream. Results are in dB per channel at the end of either input.
asetnsamples
Set the number of samples per each output audio frame ๐ธ.
The last output packet may contain a different number of samples, since the filter will flush all the remaining samples when the input audio signals its end. No cap.
The filter accepts the following options:
nb_out_samples,nโ set the number of frames per each output audio frame. The number is intended as the number of samples per each channel. Default value is1024.pad,pโ if set to1, the filter will pad the last audio frame with zeroes, so that the last frame contains the same number of samples as the previous ones. Default value is1.
For example, to set the number of per-frame samples to 1234 and disable padding for the last frame, use:
asetnsamples=n=1234:p=0
asetrate
Set the sample rate without altering the PCM data ๐. This will result in a change of speed and pitch โ iconic behavior, honestly.
The filter accepts the following options:
sample_rate,rโ set the output sample rate. Default is44100Hz.
ashowinfo
Show a line containing various information for each input audio frame ๐. The input audio is not modified โ it's purely observational, main character energy.
The shown line contains a sequence of key/value pairs of the form key:value.
The following values are shown in the output:
nโ the (sequential) number of the input frame, starting from0.ptsโ the presentation timestamp of the input frame, in time base units; the time base depends on the filter input pad, and is usually1/sample_rate.pts_timeโ the presentation timestamp of the input frame in seconds.fmtโ the sample format.chlayoutโ the channel layout.rateโ the sample rate for the audio frame.nb_samplesโ the number of samples (per channel) in the frame.checksumโ the Adler-32 checksum (printed in hexadecimal) of the audio data. For planar audio, the data is treated as if all the planes were concatenated.plane_checksumsโ a list of Adler-32 checksums for each data plane.
asisdr
Measure Audio Scaled-Invariant Signal-to-Distortion Ratio ๐.
This filter takes two audio streams for input, and outputs the first audio stream. Results are in dB per channel at the end of either input. Same vibe as asdr, different flavor โจ.
asoftclip
Apply audio soft clipping ๐ฅ.
Soft clipping is a type of distortion effect where the amplitude of a signal is saturated along a smooth curve, rather than the abrupt shape of hard-clipping. It's giving gentle. It's giving rounded edges.
This filter accepts the following options:
typeโ set the type of soft-clipping.
It accepts the following values:
hardtanhatancubicexpalgquinticsinerf
thresholdโ set the threshold from where to start clipping. Default value is0dB or1.outputโ set gain applied to output. Default value is0dB or1.paramโ set an additional parameter which controls the sigmoid function.oversampleโ set the oversampling factor.
Commands
This filter supports the all above options as commands ๐.
aspectralstats
Display frequency domain statistical information about the audio channels ๐ฆ. Statistics are calculated and stored as metadata for each audio channel and for each audio frame. So much data. So organized.
It accepts the following option:
win_sizeโ set the window length in samples. Default value is2048. Allowed range is from32to65536.win_funcโ set the window function.
It accepts the following values:
rectbartletthann,hanninghammingblackmanwelchflattopbharrisbnuttallbhannsinenuttalllanczosgausstukeydolphcauchyparzenpoissonbohmankaiser
Default is hann.
overlapโ set window overlap. Allowed range is from0to1. Default value is0.5.measureโ select the parameters which are measured. The metadata keys can be used as flags, default isall, which measures everything.nonedisables all measurement.
A list of each metadata key follows:
meanvariancecentroidspreadskewnesskurtosisentropyflatnesscrestfluxslopedecreaserolloff
asr
Automatic Speech Recognition ๐ค.
This filter uses PocketSphinx for speech recognition. To enable compilation of this filter, you need to configure FFmpeg with --enable-pocketsphinx.
It accepts the following options:
rateโ set sampling rate of input audio. Defaults is16000. This need to match speech models, otherwise one will get poor results โ so like, actually check this one ๐.hmmโ set dictionary containing acoustic model files.dictโ set pronunciation dictionary.lmโ set language model file.lmctlโ set language model set.lmnameโ set which language model to use.logfnโ set output for log messages.
The filter exports recognized speech as the frame metadata lavfi.asr.text.
astats
Display time domain statistical information about the audio channels ๐. Statistics are calculated and displayed for each audio channel and, where applicable, an overall figure is also given. It's a whole report card for your audio, fr fr.
It accepts the following option:
lengthโ short window length in seconds, used for peak and through RMS measurement. Default is0.05(50 milliseconds). Allowed range is[0 - 10].metadataโ set metadata injection. All the metadata keys are prefixed withlavfi.astats.X, whereXis the channel number starting from1or the stringOverall. Default is disabled.
Available keys for each channel are: Bit_depth Crest_factor DC_offset Dynamic_range Entropy Flat_factor Max_difference Max_level Mean_difference Min_difference Min_level Noise_floor Noise_floor_count Number_of_Infs Number_of_NaNs Number_of_denormals Peak_count Abs_Peak_count Peak_level RMS_difference RMS_peak RMS_trough Zero_crossings Zero_crossings_rate
and for Overall: Bit_depth DC_offset Entropy Flat_factor Max_difference Max_level Mean_difference Min_difference Min_level Noise_floor Noise_floor_count Number_of_Infs Number_of_NaNs Number_of_denormals Number_of_samples Peak_count Abs_Peak_count Peak_level RMS_difference RMS_level RMS_peak RMS_trough
For example, a full key looks like lavfi.astats.1.DC_offset or lavfi.astats.Overall.Peak_count.
Read below for the description of the keys.
resetโ set the number of frames over which cumulative stats are calculated before being reset. Default is disabled.measure_perchannelโ select the parameters which are measured per channel. The metadata keys can be used as flags, default isall, which measures everything.nonedisables all per channel measurement.measure_overallโ select the parameters which are measured overall. The metadata keys can be used as flags, default isall, which measures everything.nonedisables all overall measurement.
A description of the measure keys follow:
noneโ no measures.allโ all measures.Bit_depthโ overall bit depth of audio, i.e. number of bits used for each sample.Crest_factorโ standard ratio of peak to RMS level (note: not in dB).DC_offsetโ mean amplitude displacement from zero.Dynamic_rangeโ measured dynamic range of audio in dB.Entropyโ entropy measured across whole audio; entropy of value near1.0is typically measured for white noise.Flat_factorโ flatness (i.e. consecutive samples with the same value) of the signal at its peak levels (i.e. eitherMin_levelorMax_level).Max_differenceโ maximal difference between two consecutive samples.Max_levelโ maximal sample level.Mean_differenceโ mean difference between two consecutive samples, i.e. the average of each difference between two consecutive samples.Min_differenceโ minimal difference between two consecutive samples.Min_levelโ minimal sample level.Noise_floorโ minimum local peak measured in dBFS over a short window.Noise_floor_countโ number of occasions (not the number of samples) that the signal attained Noise floor.Number_of_Infsโ number of samples with an infinite value.Number_of_NaNsโ number of samples with a NaN (not a number) value.Number_of_denormalsโ number of samples with a subnormal value.Number_of_samplesโ number of samples.Peak_countโ number of occasions (not the number of samples) that the signal attained eitherMin_levelorMax_level.Abs_Peak_countโ number of occasions that the absolute samples taken from the signal attained max absolute value ofMin_levelandMax_level.Peak_levelโ standard peak level measured in dBFS.RMS_differenceโ Root Mean Square difference between two consecutive samples.RMS_levelโ standard RMS level measured in dBFS.RMS_peak,RMS_troughโ peak and through values for RMS level measured over a short window, measured in dBFS.Zero crossingsโ number of points where the waveform crosses the zero level axis.Zero crossings rateโ rate of Zero crossings and number of audio samples.
asubboost
Boost subwoofer frequencies ๐.
The filter accepts the following options:
dryโ set dry gain, how much of original signal is kept. Allowed range is from0to1. Default value is1.0.wetโ set wet gain, how much of filtered signal is kept. Allowed range is from0to1. Default value is1.0.boostโ set max boost factor. Allowed range is from1to12. Default value is2.decayโ set delay line decay gain value. Allowed range is from0to1. Default value is0.0.feedbackโ set delay line feedback gain value. Allowed range is from0to1. Default value is0.9.cutoffโ set cutoff frequency in Hertz. Allowed range is50to900. Default value is100.slopeโ sets how steep the cutoff slope is, bestie. Allowed range is0.0001to1. Default value is0.5.delayโ sets the delay. Allowed range is from1to100. Default value is20.channelsโ which channels get processed. Default value is all available ones, slay.
Commands
This filter supports the all above options as commands. Periodt. ๐
asubcut ๐ โ bye-bye subwoofer frequencies
Cut subwoofer frequencies. This filter lets you set a custom, steeper roll off than the highpass filter, so it can more attenuate frequency content in the stop-band. Itโs giving โquiet down, bassโ energy.
The filter accepts the following options:
cutoffโ cutoff frequency in Hertz. Allowed range is2to200. Default value is20.orderโ filter order. Available values are from3to20. Default value is10.levelโ input gain level. Allowed range is from0to1. Default value is1.
Commands
This filter supports the all above options as commands. ๐ซถ
asupercut โจ โ high-key shooing away the super-highs
Cut super frequencies. The filter accepts the following options:
cutoffโ cutoff frequency in Hertz. Allowed range is20000to192000. Default value is20000.orderโ filter order. Available values are from3to20. Default value is10.levelโ input gain level. Allowed range is from0to1. Default value is1.
Commands
This filter supports the all above options as commands. ๐ฆ
asuperpass ๐ธ โ high-order Butterworth band-pass moment
Apply high order Butterworth band-pass filter. The filter accepts the following options:
centerfโ center frequency in Hertz. Allowed range is2to999999. Default value is1000.orderโ filter order. Available values are from4to20. Default value is4.qfactorโ Q-factor. Allowed range is from0.01to100. Default value is1.levelโ input gain level. Allowed range is from0to2. Default value is1.
Commands
This filter supports the all above options as commands. ๐
asuperstop ๐ โ high-order Butterworth band-stop, not me making a whole vibe
Apply high order Butterworth band-stop filter. The filter accepts the following options:
centerfโ center frequency in Hertz. Allowed range is2to999999. Default value is1000.orderโ filter order. Available values are from4to20. Default value is4.qfactorโ Q-factor. Allowed range is from0.01to100. Default value is1.levelโ input gain level. Allowed range is from0to2. Default value is1.
Commands
This filter supports the all above options as commands. ๐ง
atempo ๐ฅ โ speed it up, slow it down, main character tempo energy
Adjust audio tempo. Okay so this filter accepts exactly one parameter, the audio tempo. If itโs not specified, the filter assumes nominal 1.0 tempo. Tempo must be in the [0.5, 100.0] range.
Note that tempo greater than2will skip some samples rather than blend them in. If for any reason this is a concern, it is always possible to daisy-chain several instances ofatempoto achieve the desired product tempo. No cap, thatโs the workaround.
Examples
- Slow down audio to 80% tempo:
atempo=0.8
- To speed up audio to 300% tempo:
atempo=3
- To speed up audio to 300% tempo by daisy-chaining two
atempoinstances:
atempo=sqrt(3),atempo=sqrt(3)
Commands
This filter supports the following commands:
tempoโ change filter tempo scale factor. Syntax for the command is :"tempo"
atilt ๐ง โ spectral tilt, but make it cute
Apply spectral tilt filter to audio stream. This filter applies any spectral roll-off slope over any specified frequency band. Itโs giving โshape the tone with one glow-up pass.โ
The filter accepts the following options:
freqโ central frequency of tilt in Hz. Default is10000Hz.slopeโ slope direction of tilt. Default is0. Allowed range is from-1to1.widthโ width of tilt. Default is1000. Allowed range is from100to10000.orderโ order of tilt filter.levelโ input volume level. Allowed range is from0to4. Default is1.
Commands
This filter supports the all above options as commands. ๐
atrim โ๏ธ โ keep just the part you want
Trim the input so that the output contains one continuous subpart of the input. Bestie, itโs literally a little audio scissors situation.
It accepts the following parameters:
startโ timestamp (in seconds) of the start of the section to keep. I.e. the audio sample with the timestamp start will be the first sample in the output.endโ specify time of the first audio sample that will be dropped, i.e. the audio sample immediately preceding the one with the timestamp end will be the last sample in the output.start_ptsโ same asstart, except this option sets the start timestamp in samples instead of seconds.end_ptsโ same asend, except this option sets the end timestamp in samples instead of seconds.durationโ the maximum duration of the output in seconds.start_sampleโ the number of the first sample that should be output.end_sampleโ the number of the first sample that should be dropped.
start, end, and duration are expressed as time duration specifications; see the Time duration section in the ffmpeg-utils(1) manual.
Note that the first two sets of the start/end options and thedurationoption look at the frame timestamp, while the_sampleoptions simply count the samples that pass through the filter. Sostart/end_ptsandstart/end_samplewill give different results when the timestamps are wrong, inexact or do not start at zero. Also note that this filter does not modify the timestamps. If you wish to have the output timestamps start at zero, insert theasetptsfilter after theatrimfilter. ๐ซถ
If multiple start or end options are set, this filter tries to be greedy and keep all samples that match at least one of the specified constraints. To keep only the part that matches all the constraints at once, chain multiple atrim filters.
The defaults are such that all the input is kept. So it is possible to set e.g. just the end values to keep everything before the specified time.
Examples:
- Drop everything except the second minute of input:
ffmpeg -i INPUT -af atrim=60:120
- Keep only the first 1000 samples:
ffmpeg -i INPUT -af atrim=end_sample=1000
axcorrelate ๐ฆ โ cross-correlation, but make it normalized and windowed
Calculate normalized windowed cross-correlation between two input audio streams.
Resulted samples are always between -1 and 1 inclusive. If result is 1, it means two input samples are highly correlated in that selected segment. Result 0 means they are not correlated at all. If result is -1, it means two input samples are out of phase, which means they cancel each other. Iconic little math moment, honestly.
The filter accepts the following options:
sizeโ size of segment over which cross-correlation is calculated. Default is256. Allowed range is from2to131072.algoโ algorithm for cross-correlation. Can be"slow"or"fast"or"best". Default is"best". The fast algorithm assumes mean values over any given segment are always zero and thus needs much less calculations to make. This is generally not true, but is valid for typical audio streams.
Examples
- Calculate correlation between channels in stereo audio stream:
ffmpeg -i stereo.wav -af channelsplit,axcorrelate=size=1024:algo=fast correlation.wav
bandpass ๐ โ two-pole Butterworth band-pass, we love a filter with lore
Apply a two-pole Butterworth band-pass filter with central frequency frequency, and (3dB-point) band-width width. The csg option selects a constant skirt gain (peak gain = Q) instead of the default: constant 0dB peak gain. The filter roll off at 6dB per octave (20dB per decade).
The filter accepts the following options:
frequency,fโ the filterโs central frequency. Default is3000.csgโ constant skirt gain if set to1. Defaults to0.width_type,tโ method to specify band-width of filter:hโ Hzqโ Q-Factoroโ octavesโ slopekโ kHz
width,wโ specify the band-width of a filter inwidth_typeunits.mix,mโ how much to use filtered signal in output. Default is1. Range is between0and1.channels,cโ which channels to filter, by default all available are filtered.normalize,nโ normalize biquad coefficients, by default is disabled. Enabling it will normalize magnitude response at DC to0dB.transform,aโ set transform type of IIR filter:didiitditdiilattsvfzdf
precision,rโ set precision of filtering:autoโ pick automatic sample format depending on surround filters.s16โ always use signed 16-bit.s32โ always use signed 32-bit.f32โ always use float 32-bit.f64โ always use float 64-bit.
block_size,bโ set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response length truncated when reaches near zero values) filtering will become linear phase; otherwise, if not big enough, it will just produce nasty artifacts.
Note that filter delay will be exactly this many samples when set to non-zero value. ๐ญ
Commands
This filter supports the following commands:
frequency,fโ change bandpass frequency. Syntax for the command is :"frequency"width_type,tโ change bandpasswidth_type. Syntax for the command is :"width_type"width,wโ change bandpass width. Syntax for the command is :"width"mix,mโ change bandpass mix. Syntax for the command is :"mix"
bandreject ๐ธ โ two-pole Butterworth band-reject, the โnot this frequencyโ filter
Apply a two-pole Butterworth band-reject filter with central frequency frequency, and (3dB-point) band-width width. The filter roll off at 6dB per octave (20dB per decade).
The filter accepts the following options:
frequency,fโ the filterโs central frequency. Default is3000.width_type,tโ method to specify band-width of filter:hโ Hzqโ Q-Factoroโ octavesโ slopekโ kHz
width,wโ specify the band-width of a filter inwidth_typeunits.mix,mโ how much to use filtered signal in output. Default is1. Range is between0and1.channels,cโ which channels to filter, by default all available are filtered.normalize,nโ normalize biquad coefficients, by default is disabled. Enabling it will normalize magnitude response at DC to0dB.transform,aโ set transform type of IIR filter:didiitditdiilattsvfzdf
precision,rโ set precision of filtering.autoโ picks the sample format automatically, based on whatever the surround filters are doing ๐s16โ always signed 16-bit, periodt.s32โ always signed 32-bit.f32โ always float 32-bit.f64โ always float 64-bit.
block_size,bโ sets the block size used for reverse IIR processing. Here's the tea โ: if you set this high enough (higher than the impulse response length truncated once it hits near-zero values), the filtering goes linear phase. If it's not big enough, you just get nasty artifacts, no cap ๐ญ.
heads up bestie: the filter delay will be exactly this many samples whenever this is set to a non-zero value. That's not a bug, that's the deal ๐
Commands ๐ฌ
This filter supports the following commands:
frequency,fโ change the bandreject frequency. Syntax for the command is:"frequency"width_type,tโ change the bandreject width_type. Syntax for the command is:"width_type"width,wโ change the bandreject width. Syntax for the command is:"width"mix,mโ change the bandreject mix. Syntax for the command is:"mix"
๐ธ bass, lowshelf
Boosts or cuts the bass (lower) frequencies of your audio, using a two-pole shelving filter whose response is basically the same vibe as the tone-controls on a standard hi-fi. This is also known as shelving equalisation (EQ), iykyk โจ.
The filter accepts the following options:
gain,gโ gives the gain at 0 Hz. Useful range is roughly-20(big cut) to+20(big boost). โ ๏ธ beware of clipping when you use a positive gain โ she will clip, fr fr.frequency,fโ sets the filter's central frequency, so you can extend or shrink the frequency range that gets boosted or cut. Default is100Hz.width_type,tโ sets the method used to specify the band-width of the filter:hโ Hzqโ Q-Factoroโ octavesโ slopekโ kHz
width,wโ determines how steep the filter's shelf transition is ๐ชpoles,pโ sets the number of poles. Default is2.mix,mโ how much of the filtered signal goes into the output. Default is1. Range is between0and1.channels,cโ which channels to filter. By default, all available channels get filtered ๐normalize,nโ normalizes the biquad coefficients. By default this is disabled. Turning it on normalizes the magnitude response at DC to0dB.transform,aโ sets the transform type of the IIR filter:didiitditdiilattsvfzdf
precision,rโ sets the precision of filtering:autoโ pick the automatic sample format depending on surround filters ๐s16โ always signed 16-bit.s32โ always signed 32-bit.f32โ always float 32-bit.f64โ always float 64-bit.
block_size,bโ sets the block size used for reverse IIR processing. If this value is set high enough (higher than the impulse response length truncated when it reaches near zero values), the filtering becomes linear phase. If it's not big enough, it'll just produce nasty artifacts ๐ญ.
note note note: the filter delay will be exactly this many samples when set to a non-zero value ๐
Commands ๐ฌ
This filter supports the following commands:
frequency,fโ change the bass frequency. Syntax for the command is:"frequency"width_type,tโ change the bass width_type. Syntax for the command is:"width_type"width,wโ change the bass width. Syntax for the command is:"width"gain,gโ change the bass gain. Syntax for the command is:"gain"mix,mโ change the bass mix. Syntax for the command is:"mix"
๐งฎ biquad
Applies a biquad IIR filter with the coefficients you give it. So like, b0, b1, b2 are the numerator coefficients and a0, a1, a2 are the denominator coefficients, respectively. And channels, c specifies which channels to filter โ by default all available channels get filtered ๐.
Commands ๐ฌ
This filter supports the following commands:
a0a1a2b0b1b2โ change the biquad parameter. Syntax for the command is:"value"mix,mโ how much of the filtered signal goes into the output. Default is1. Range is between0and1.channels,cโ which channels to filter. By default all available channels are filtered.normalize,nโ normalizes the biquad coefficients. By default this is disabled. Enabling it normalizes the magnitude response at DC to0dB.transform,aโ sets the transform type of the IIR filter:didiitditdiilattsvfzdf
precision,rโ sets the precision of filtering:autoโ pick the automatic sample format depending on surround filters.s16โ always signed 16-bit.s32โ always signed 32-bit.f32โ always float 32-bit.f64โ always float 64-bit.
block_size,bโ sets the block size used for reverse IIR processing. If this value is set high enough (higher than the impulse response length truncated when it reaches near zero values), the filtering becomes linear phase. Otherwise, if it's not big enough, it'll just produce nasty artifacts ๐ญ.
the filter delay will be exactly this many samples when set to a non-zero value. yes, again. it's that kind of option ๐
๐ง bs2b
The Bauer stereo to binaural transformation โ it makes stereo audio records sound better when you're listening on headphones ๐.
To enable compilation of this filter you need to configure FFmpeg with --enable-libbs2b. (yes, that flag, exactly that string, don't get cute with it โจ)
It accepts the following parameters:
profileโ pre-defined crossfeed level:defaultโ default level (fcut=700,feed=50).cmoyโ Chu Moy circuit (fcut=700,feed=60).jmeierโ Jan Meier circuit (fcut=650,feed=95).
fcutโ cut frequency (in Hz).feedโ feed level (in Hz).
๐บ๏ธ channelmap
Remaps input channels to new locations ๐ฆ.
It accepts the following parameters:
mapโ maps channels from input to output. The argument is a'|'-separated list of mappings, each in thein_channel-out_channelorin_channelform.in_channelcan be either the name of the input channel (e.g.FLfor front left) or its index in the input channel layout.out_channelis the name of the output channel or its index in the output channel layout. Ifout_channelisn't given, then it's implicitly an index, starting with zero and increasing by one for each mapping. Mixing different types of mappings is not allowed and will result in a parse error ๐.channel_layoutโ the channel layout of the output stream. If not specified, then the filter will guess it based on theout_channelnames or the number of mappings.
careful bestie: guessed layouts will not necessarily contain channels in the order of the mappings ๐
If no mapping is present, the filter will implicitly map input channels to output channels, preserving indices.
Examples ๐ธ
- For example, assuming a 5.1+downmix input MOV file:
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
will create an output WAV file tagged as stereo, from the downmix channels of the input โจ
- To fix a 5.1 WAV improperly encoded in AAC's native channel order:
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:5.1' out.wav
๐งฉ channelsplit
Splits each channel from an input audio stream into its own separate output stream ๐.
It accepts the following parameters:
channel_layoutโ the channel layout of the input stream. Default is"stereo".channelsโ a channel layout describing the channels to be extracted as separate output streams, or"all"to extract each input channel as a separate stream. Default is"all".
choosing channels that aren't present in the channel layout of the input will result in an error ๐ญ
Examples ๐
- For example, assuming a stereo input MP3 file:
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
will create an output Matroska file with two audio streams โ one containing only the left channel, and the other the right channel ๐
- Split a 5.1 WAV file into per-channel files:
ffmpeg -i in.wav -filter_complex
'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
-map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
side_right.wav
- Extract only LFE from a 5.1 WAV file:
ffmpeg -i in.wav -filter_complex 'channelsplit=channel_layout=5.1:channels=LFE[LFE]'
-map '[LFE]' lfe.wav
๐ chorus
Adds a chorus effect to the audio ๐ถ.
Can make a single vocal sound like a whole chorus, but it also works on instrumentation. Iconic.
Chorus is kind of like an echo effect with a short delay โ but with echo the delay is constant, whereas with chorus it's varied using sinusoidal or triangular modulation. The modulation depth defines the range the modulated delay is played before or after the delay. So the delayed sound will sound slower or faster, i.e. the delayed sound is tuned around the original one, like in a chorus where some vocals are slightly off key ๐ค.
It accepts the following parameters:
in_gainโ sets the input gain. Default is0.4.out_gainโ sets the output gain. Default is0.4.delaysโ sets the delays. A typical delay is around40msto60ms.decaysโ sets the decays.speedsโ sets the speeds.depthsโ sets the depths.
Examples ๐ฆ
- A single delay:
chorus=0.7:0.9:55:0.4:0.25:2
- Two delays:
chorus=0.6:0.9:50|60:0.4|0.32:0.25|0.4:2|1.3
- Fuller sounding chorus with three delays:
chorus=0.5:0.9:50|60|40:0.4|0.32|0.3:0.25|0.4|0.3:2|2.3|1.3
๐ compand
Compresses or expands the dynamic range of your audio ๐ฅ.
It accepts the following parameters:
attacks,decaysโ a list of times in seconds, per channel, over which the instantaneous level of the input signal is averaged to work out its volume.attacksrefers to an increase of volume, anddecaysrefers to a decrease of volume.
For most situations, the attack time (how fast it responds to the audio getting louder) should be shorter than the decay time, because the human ear is more sensitive to sudden loud audio than to sudden soft audio ๐. A typical value for attack is 0.3 seconds and a typical value for decay is 0.8 seconds.
If the number of attacks & decays you specify is lower than the number of channels, the last set attack/decay will be used for all the remaining channels ๐
pointsโ the actual transfer function points, bestie, given in dB relative to the max possible signal amplitude ๐ you define each key points list with this syntax:"x0/y0|x1/y1|x2/y2|...."or"x0/y0 x1/y1 x2/y2 ...."
The input values must be in strictly increasing order, but the transfer function itself doesn't have to be monotonically rising, no cap. The point "0/0" is assumed but can be overridden (by "0/out-dBn"). Typical values for the transfer function are "-70/-70|-60/-20|1/0".
soft-kneeโ sets the curve radius in dB for all joints โจ defaults to0.01.gainโ sets the additional gain in dB applied at all points on the transfer function, so you can tweak the overall gain super easily ๐ defaults to0.volumeโ sets an initial volume, in dB, assumed for each channel when filtering starts. This lets you supply a nominal level upfront so that, like, a very large gain isn't applied to initial signal levels before the companding has even begun to operate ๐ a typical value for audio that starts out quiet is-90dB. Defaults to0.delayโ sets a delay, in seconds. The input audio is analyzed immediately, but the audio is delayed before being fed to the volume adjuster. If you specify a delay approximately equal to the attack/decay times, the filter gets to effectively operate in predictive rather than reactive mode ๐ defaults to0.
Examples
- Make music with both quiet and loud passages suitable for listening to in a noisy environment:
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
Another example for audio with whisper and explosion parts:
compand=0|0:1|1:-90/-900|-70/-70|-30/-9|0/-3:6:0:0:0
- A noise gate for when the noise is at a lower level than the signal:
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
- Here's another noise gate, this time for when the noise is at a higher level than the signal (which makes it, in some ways, similar to squelch):
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
- 2:1 compression starting at -6dB:
compand=points=-80/-80|-6/-6|0/-3.8|20/3.5
- 2:1 compression starting at -9dB:
compand=points=-80/-80|-9/-9|0/-5.3|20/2.9
- 2:1 compression starting at -12dB:
compand=points=-80/-80|-12/-12|0/-6.8|20/1.9
- 2:1 compression starting at -18dB:
compand=points=-80/-80|-18/-18|0/-9.8|20/0.7
- 3:1 compression starting at -15dB:
compand=points=-80/-80|-15/-15|0/-10.8|20/-5.2
- Compressor/Gate:
compand=points=-80/-105|-62/-80|-15.4/-15.4|0/-12|20/-7.6
- Expander:
compand=attacks=0:points=-80/-169|-54/-80|-49.5/-64.6|-41.1/-41.1|-25.8/-15|-10.8/-4.5|0/0|20/8.3
- Hard limiter at -6dB:
compand=attacks=0:points=-80/-80|-6/-6|20/-6
- Hard limiter at -12dB:
compand=attacks=0:points=-80/-80|-12/-12|20/-12
- Hard noise gate at -35 dB:
compand=attacks=0:points=-80/-115|-35.1/-80|-35/-35|20/20
- Soft limiter:
compand=attacks=0:points=-80/-80|-12.4/-12.4|-6/-8|0/-6.8|20/-2.8
๐ธ compensationdelay
The Compensation Delay Line is a metric-based delay that exists to compensate for differing positions of microphones or speakers ๐ค
Okay so picture it: you recorded guitar with two mics placed in different locations. Because the front of a sound wave has a fixed speed under normal conditions, the phasing of the microphones can vary and depends on their location and interposition. The best sound mix happens when those mics are in phase (synchronized) โจ note that a distance of ~30 cm between microphones makes one microphone capture the signal in antiphase to the other one, which makes the final mix sound moody ๐ญ this filter helps solve those phasing problems by adding different delays to each microphone track and making them synchronized.
You get the best result when you take one track as base and synchronize the other tracks one by one with it ๐ remember that synchronization/delay tolerance depends on sample rate too โ higher sample rates will give you more tolerance.
The filter accepts the following parameters:
mmโ set millimeters distance. This is the compensation distance for fine tuning. Default is0.cmโ set cm distance. This is the compensation distance for tightening the distance setup. Default is0.mโ set meters distance. This is the compensation distance for hard distance setup. Default is0.dryโ set dry amount, i.e. the amount of unprocessed (dry) signal. Default is0.wetโ set wet amount, i.e. the amount of processed (wet) signal. Default is1.tempโ set temperature in degrees Celsius. This is the temperature of the environment. Default is20.
Commands
This filter supports the all above options as commands. ๐
๐ง crossfeed
Applies a headphone crossfeed filter.
Crossfeed is the process of blending the left and right channels of a stereo audio recording, and it's mainly used to reduce extreme stereo separation of low frequencies. The intent is to produce a more speaker-like sound for the listener ๐ซถ
The filter accepts the following options:
strengthโ set the strength of crossfeed. Default is0.2. Allowed range is from0to1. This sets the gain of the low shelf filter for the side part of the stereo image. Default is-6dB. Max allowed is-30db when strength is set to1.rangeโ set the soundstage wideness. Default is0.5. Allowed range is from0to1. This sets the cut off frequency of the low shelf filter. Default is cut off near1550Hz. With range set to1the cut off frequency is set to2100Hz.slopeโ set the curve slope of the low shelf filter. Default is0.5. Allowed range is from0.01to1.level_inโ set input gain. Default is0.9.level_outโ set output gain. Default is1.block_sizeโ set the block size used for reverse IIR processing. If this value is set high enough (higher than the impulse response length truncated when it reaches near-zero values) the filtering becomes linear phase; otherwise, if it's not big enough, it'll just produce nasty artifacts ๐
Note that the filter delay will be exactly this many samples when set to a non-zero value.
Commands
This filter supports the all above options as commands.
๐ฆ crystalizer
A simple algorithm for audio noise sharpening โจ this filter linearly increases the differences between each audio sample.
The filter accepts the following options:
iโ sets the intensity of the effect (default:2.0). Must be in range between-10.0(unchanged sound) to10.0(maximum effect). To do inverse filtering, use a negative value.cโ enable clipping. By default it's enabled.
Commands
This filter supports the all above options as commands. ๐
๐ dcshift
Applies a DC shift to the audio.
This can be genuinely useful for removing a DC offset (caused perhaps by a hardware problem in the recording chain) from your audio ๐ the effect of a DC offset is reduced headroom and hence volume. The astats filter can be used to determine if a signal has a DC offset, fyi.
shiftโ set the DC shift, allowed range is[-1, 1]. It indicates the amount to shift the audio.limitergainโ optional. It should have a value much less than1(e.g.0.05or0.02) and is used to prevent clipping.
๐ deesser
Applies de-essing to the audio samples.
iโ set intensity for triggering de-essing. Allowed range is from0to1. Default is0.mโ set the amount of ducking on the treble part of the sound. Allowed range is from0to1. Default is0.5.fโ how much of the original frequency content to keep when de-essing. Allowed range is from0to1. Default is0.5.sโ set the output mode.
It accepts the following values:
iโ pass input unchanged.oโ pass ess filtered out.eโ pass only ess.
Default value is o.
๐ dialoguenhance
Enhances dialogue in stereo audio.
This filter accepts stereo input and produces surround (3.0) channels output ๐ the newly produced front center channel has enhanced speech dialogue that was originally available in both stereo channels. This filter outputs the front left and front right channels the same as they were available in the stereo input.
The filter accepts the following options:
originalโ set the original center factor to keep in the front center channel output. Allowed range is from0to1. Default value is1.enhanceโ set the dialogue enhance factor to put in the front center channel output. Allowed range is from0to3. Default value is1.voiceโ set the voice detection factor. Allowed range is from2to32. Default value is2.
Commands
This filter supports the all above options as commands. ๐
๐ฅ drmeter
Measures audio dynamic range.
DR values of 14 and higher is found in very dynamic material. DR of 8 to 13 is found in transition material. And anything less that 8 have very poor dynamics and is very compressed ๐ญ
The filter accepts the following options:
lengthโ set window length in seconds used to split audio into segments of equal length. Default is3seconds.
๐ dynaudnorm
Dynamic Audio Normalizer, bestie.
This filter applies a certain amount of gain to the input audio in order to bring its peak magnitude to a target level (e.g. 0 dBFS) โจ but here's the twist โ in contrast to more "simple" normalization algorithms, the Dynamic Audio Normalizer dynamically re-adjusts the gain factor to the input audio. This allows it to apply extra gain to the "quiet" sections of the audio while avoiding distortions or clipping the "loud" sections. In other words: the Dynamic Audio Normalizer will "even out" the volume of quiet and loud sections, in the sense that the volume of each section is brought to the same target level ๐๏ธ note, however, that the Dynamic Audio Normalizer achieves this goal without applying "dynamic range compressing". It will retain 100% of the dynamic range within each section of the audio file. periodt. ๐
framelen,fโ sets the frame length in milliseconds, anywhere from 10 to 8000 ms, and the default is 500 ms. Okay so here's the tea: the Dynamic Audio Normalizer chews through your audio in little chunks called frames, because a peak magnitude literally means nothing for one single sample value โ you need a contiguous sequence of samples to find a peak in. A "standard" normalizer would just take the peak of the whole entire file, but the D.A.N. does it frame by frame, individually, like the main character it is. Frame length is in milliseconds, default500because that's been found to give good results with most files. Ngl though, the exact frame length in number of samples gets determined automatically based on the sampling rate of the individual input audio file. ๐gausssize,gโ sets the Gaussian filter window size, range 3 to 301, and it must be an odd number. Default is31. This is probably the most important parameter of the whole Dynamic Audio Normalizer, no cap. The window size is specified in frames, centered around the current frame, and for simplicity it has to be odd. So the default31takes into account the current frame plus the 15 preceding frames and the 15 subsequent frames. Bigger window โ stronger smoothing โ less gain variation โ slower gain adaptation. Smaller window โ weaker smoothing โ more gain variation โ faster gain adaptation. In other words: the more you crank this value up, the more the Dynamic Audio Normalizer behaves like a "traditional" normalization filter, and the more you drop it down, the more it behaves like a dynamic range compressor. It's giving duality. โจpeak,pโ sets the target peak value, i.e. the highest permissible magnitude level for the normalized audio input. The filter tries to approach that target peak as closely as possible while also making absolutely sure the normalized signal never exceeds it. A frame's maximum local gain factor is imposed directly by the target peak magnitude. Default is0.95, which leaves a headroom of 5%*. It is not recommended to go above this value, bestie, don't do it. ๐maxgain,mโ sets the maximum gain factor, range 1.0 to 100.0, default10.0. The D.A.N. works out the maximum possible (local) gain factor for each input frame โ the biggest gain that doesn't cause clipping or distortion โ and that's determined by the frame's highest magnitude sample. But it also bounds that frame's max gain by a predetermined (global) maximum gain factor, so "silent" or almost-silent frames don't get insanely boosted. Default10.0should be enough for most inputs and it's usually not recommended to increase itโฆ though for input with an extremely low overall volume level you might need to allow even higher gain factors. Important: it does not just apply a "hard" threshold (like cutting off values above it) โ a "sigmoid" threshold function is applied, so gain factors smoothly approach the threshold and never exceed it. Chef's kiss. ๐targetrms,rโ sets the target RMS, range 0.0 to 1.0, default0.0which means disabled. By default the Dynamic Audio Normalizer does "peak" normalization, meaning each frame's maximum local gain factor is defined (only) by that frame's highest magnitude sample, so samples can be amplified as much as possible without exceeding the max signal level and without clipping. Optionally though, it can also take the frame's root mean square (RMS) into account. In electrical engineering, RMS is commonly used to determine the power of a time-varying signal, and it's considered a better approximation of "perceived loudness" than just staring at peak magnitude. So by adjusting all frames to a constant RMS value you get a uniform "perceived loudness". If you specify a target RMS, a frame's local gain factor is the factor that would result in exactly that RMS value. Note that the max local gain factor is still restricted by the frame's highest magnitude sample, to prevent clipping. Safety first. ๐ฆcoupling,nโ enables channels coupling, and by default it's enabled. Default behavior: amplify all channels by the same amount, same gain factor on every channel, so the maximum possible gain factor is set by the "loudest" channel. But sometimes recordings have uneven channel volumes, like one channel is "quieter" than the other(s) โ in that case you can use this option to disable channel coupling, and the gain factor gets determined independently per channel, depending only on that individual channel's highest magnitude sample. That harmonizes the volume across channels. Obsessed. ๐ซถcorrectdc,cโ enables DC bias correction, and by default it's disabled. Quick lil context: an audio signal in the time domain is a sequence of sample values, represented in the-1.0to1.0range here regardless of the original input format. Normally the waveform should be centered around the zero point โ mean value of all samples in a file or single frame should be0.0or at least super close. If the mean deviates significantly from0.0in either direction, that's a DC bias or DC offset, and it's clearly undesirable, so this option exists. With it enabled, the D.A.N. figures out the mean value (the "DC correction" offset) of each input frame and subtracts it from all of that frame's sample values, so everything's centered around0.0again. And to avoid "gaps" at the frame boundaries, the DC correction offset values get interpolated smoothly between neighbouring frames. Seamless, we love to see it. ๐ธaltboundary,bโ enables alternative boundary mode, and by default it's disabled. The D.A.N. considers a certain neighbourhood around each frame โ preceding frames and subsequent frames โ but for the "boundary" frames at the very beginning and very end of the audio file, not all neighbours exist. First few frames: preceding ones unknown. Last few frames: subsequent ones unknown. So which gain factors should the missing frames get? Two modes, bestie. The default boundary mode assumes a gain factor of exactly1.0for the missing frames, giving you a smooth "fade in" at the start and "fade out" at the end of the input respectively. ๐compress,sโ sets the compress factor, range 0.0 to 30.0, default0.0. By default the D.A.N. does no "traditional" compression โ signal peaks aren't pruned, so the full dynamic range stays intact within each local neighbourhood. But sometimes you want the normalization algorithm combined with a more "traditional" compression, so there's this optional compression (thresholding) function. If (and only if!) it's enabled, all input frames go through a soft knee thresholding function prior to the actual normalization process โ put simply, it prunes all samples whose magnitude exceeds a certain threshold value. And it's not a fixed threshold either, the threshold gets adjusted for each individual frame. Generally smaller parameters โ stronger compression and vice versa. Values below3.0are not recommended because audible distortion may appear. You've been warned. ๐ฅthreshold,tโ sets the target threshold value, which is the lowest permissible magnitude level for the audio input that will be normalized. If the input frame volume is above this value, the frame gets normalized; otherwise the frame may not be normalized at all. Default is0, meaning all input frames get normalized. Mostly useful if you don't want digital noise getting amplified. ๐channels,hโ specify which channels to filter. By default, all available channels are filtered. ๐overlap,oโ specify overlap for frames. If set to0(the default) no frame overlapping is done. Using values>0and<1gives less conservative gain adjustments, like when theframelenoption is set to a smaller value โ and if theframelenoption value is compensated for non-zero overlap, the gain adjustments end up smoother across time compared to the zero overlap case. โญcurve,vโ specify the peak mapping curve expression used when calculating the gain applied to frames. The max output frame gain will still be limited by the other options mentioned previously for this filter, so it's not a free-for-all.
The expression can contain the following constants:
chโ current channel numbersnโ current sample numbernb_channelsโ number of channelstโ timestamp expressed in secondssrโ sample rate
pโ the current frame's peak value ๐ฉท
โก Commands โก
This filter is so command-friendly โ it supports the all above options as commands. iykyk ๐
๐ง earwax ๐ง
Okay so this one literally makes audio easier to listen to on headphones. It adds cues to 44.1kHz stereo (i.e. audio CD format) audio, so that when you're listening on headphones the stereo image gets moved out of the inside of your head (which is, like, the standard headphone situation ๐ญ) and puts it outside and in front of the listener instead (which is the standard speaker situation). Iconic behaviour honestly.
Ported from SoX. periodt. ๐ซถ
๐๏ธ equalizer ๐๏ธ
Apply a two-pole peaking equalisation (EQ) filter. With this filter, the signal-level at and around a selected frequency can be increased or decreased โ and unlike bandpass and bandreject filters โ everything at all the other frequencies stays unchanged. Fr fr, nothing else gets touched. โจ
And bestie, here's the slay part: to produce complex equalisation curves, this filter can be given several times, each with a different central frequency. Stack 'em. ๐
The filter accepts the following options:
frequency,fโ sets the filter's central frequency in Hz.width_type,tโ sets the method to specify the band-width of the filter:hโ Hzqโ Q-Factoroโ octavesโ slopekโ kHz
width,wโ specifies the band-width of a filter in width_type units.gain,gโ sets the required gain or attenuation in dB. โ ๏ธ Beware of clipping when using a positive gain โ like, don't come crying to me.mix,mโ how much to use the filtered signal in the output. Default is1. Range is between0and1.channels,cโ specifies which channels to filter. By default, all available channels are filtered.normalize,nโ normalizes biquad coefficients. By default it's disabled. Enabling it will normalize the magnitude response at DC to 0dB.transform,aโ sets the transform type of the IIR filter:didiitditdiilattsvfzdf
precision,rโ sets the precision of filtering:autoโ pick automatic sample format depending on surround filters.s16โ always use signed 16-bit.s32โ always use signed 32-bit.f32โ always use float 32-bit.f64โ always use float 64-bit.
block_size,bโ sets the block size used for reverse IIR processing. If this value is set to a high enough value (higher than the impulse response length truncated when it reaches near zero values), filtering will become linear phase. Otherwise, if it's not big enough, it'll just produce nasty artifacts ๐.
Note that the filter delay will be exactly this many samples when set to a non-zero value.
๐ธ Examples ๐ธ
- Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
equalizer=f=1000:t=h:width=200:g=-10
- Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
equalizer=f=1000:t=q:w=1:g=2,equalizer=f=100:t=q:w=2:g=-5
๐ Commands ๐
This filter supports the following commands:
frequency,fโ change equalizer frequency. Syntax for the command is:"frequency"width_type,tโ change equalizer width_type. Syntax for the command is:"width_type"width,wโ change equalizer width. Syntax for the command is:"width"gain,gโ change equalizer gain. Syntax for the command is:"gain"mix,mโ change equalizer mix. Syntax for the command is:"mix"
๐ extrastereo ๐
Linearly increases the difference between left and right channels, which adds some sort of "live" effect to playback. It's giving concert-hall energy, ngl ๐ค
The filter accepts the following options:
mโ sets the difference coefficient (default:2.5).0.0means mono sound (average of both channels), with1.0the sound will be unchanged, and with-1.0left and right channels will be swapped. Swapped!! ๐ญcโ enable clipping. By default it's enabled.
โก Commands โก
This filter supports the all above options as commands.
๐ฅ firequalizer ๐ฅ
Apply FIR Equalization using arbitrary frequency response. Yes, arbitrary. Main character filter, honestly. ๐
The filter accepts the following option:
gainโ sets the gain curve equation (in dB). The expression can contain variables:fโ the evaluated frequencysrโ sample ratechโ channel number, set to0when multichannels evaluation is disabledchidโ channel id, seelibavutil/channel_layout.h, set to the first channel id when multichannels evaluation is disabledchsโ number of channelschlayoutโ channel_layout, seelibavutil/channel_layout.h
and functions:
gain_interpolate(f)โ interpolate gain on frequencyfbased ongain_entrycubic_interpolate(f)โ same asgain_interpolate, but smoother โจ
This option is also available as a command. Default is gain_interpolate(f).
gain_entryโ sets the gain entry for thegain_interpolatefunction. The expression can contain functions:entry(f, g)โ store gain entry at frequencyfwith valueg
This option is also available as a command.
delayโ sets the filter delay in seconds. Higher value means more accurate. Default is0.01.accuracyโ sets the filter accuracy in Hz. Lower value means more accurate. Default is5.wfuncโ sets the window function. Acceptable values are:rectangularโ rectangular window, useful when the gain curve is already smoothhannโ hann window (default)hammingโ hamming windowblackmanโ blackman windownuttall3โ 3-terms continuous 1st derivative nuttall windowmnuttall3โ minimum 3-terms discontinuous nuttall windownuttallโ 4-terms continuous 1st derivative nuttall windowbnuttallโ minimum 4-terms discontinuous nuttall (blackman-nuttall) windowbharrisโ blackman-harris windowtukeyโ tukey window
fixedโ if enabled, use a fixed number of audio samples. This improves speed when filtering with large delay. Default is disabled.multiโ enable multichannels evaluation on gain. Default is disabled.zero_phaseโ enable zero phase mode by subtracting timestamp to compensate delay. Default is disabled.scaleโ sets the scale used by gain. Acceptable values are:linlinโ linear frequency, linear gainlinlogโ linear frequency, logarithmic (in dB) gain (default)loglinโ logarithmic (in octave scale where 20 Hz is 0) frequency, linear gainloglogโ logarithmic frequency, logarithmic gain
dumpfileโ sets the file for dumping, suitable for gnuplot.dumpscaleโ sets the scale fordumpfile. Acceptable values are the same as thescaleoption. Default islinlog.fft2โ enable 2-channel convolution using complex FFT. This improves speed significantly. Default is disabled.min_phaseโ enable minimum phase impulse response. Default is disabled.
๐ฆ Examples ๐ฆ
- lowpass at 1000 Hz:
firequalizer=gain='if(lt(f,1000), 0, -INF)'
- lowpass at 1000 Hz with
gain_entry:
firequalizer=gain_entry='entry(1000,0); entry(1001, -INF)'
- custom equalization:
firequalizer=gain_entry='entry(100,0); entry(400, -4); entry(1000, -6); entry(2000, 0)'
- higher delay with zero phase to compensate delay:
firequalizer=delay=0.1:fixed=on:zero_phase=on
- lowpass on left channel, highpass on right channel:
firequalizer=gain='if(eq(chid,1), gain_interpolate(f), if(eq(chid,2), gain_interpolate(1e6+f), 0))'
:gain_entry='entry(1000, 0); entry(1001,-INF); entry(1e6+1000,0)':multi=on
๐ flanger ๐
Apply a flanging effect to the audio. That swirly jet-plane sound, you know the one ๐ฉ๏ธโจ
The filter accepts the following options:
delayโ sets base delay in milliseconds. Range from0to30. Default value is0.depthโ sets added sweep delay in milliseconds. Range from0to10. Default value is2.regenโ sets percentage regeneration (delayed signal feedback). Range from-95to95. Default value is0.widthโ sets percentage of delayed signal mixed with original. Range from0to100. Default value is71.speedโ sets sweeps per second (Hz). Range from0.1to10. Default value is0.5.shapeโ sets the swept wave shape; can betriangularorsinusoidal. Default value issinusoidal.phaseโ sets swept wave percentage-shift for multi channel. Range from0to100. Default value is25.interpโ sets delay-line interpolation,linearorquadratic. Default islinear.
๐ haas ๐
Apply the Haas effect to audio. Cute little psychoacoustic trick, lowkey obsessed ๐
Note that this makes the most sense to apply on mono signals. With this filter applied to mono signals it gives some directionality and stretches its stereo image.
The filter accepts the following options:
level_inโ sets input level. By default it's1, or 0dB.level_outโ sets output level. By default it's1, or 0dB.side_gainโ sets gain applied to the side part of the signal. By default it's1.middle_sourceโ sets the kind of middle source. Can be one of the following:leftโ pick left channel.rightโ pick right channel.midโ pick middle part signal of stereo image.sideโ pick side part signal of stereo image.
middle_phaseโ change middle phase. By default it's disabled.left_delayโ sets left channel delay. By default it's2.05milliseconds.left_balanceโ sets left channel balance. By default it's-1.left_gainโ sets left channel gain. By default it's1.left_phaseโ change left phase. By default it's disabled.right_delayโ sets right channel delay. By default it's2.12milliseconds.right_balanceโ sets right channel balance. By default it's1.right_gainโ sets right channel gain. By default it's1.right_phaseโ change right phase. By default it's enabled.
๐ฟ hdcd ๐ฟ
Decodes High Definition Compatible Digital (HDCD) data. A 16-bit PCM stream with embedded HDCD codes gets expanded into a 20-bit PCM stream. Glow-up of the century honestly โจ
The filter supports the Peak Extend and Low-level Gain Adjustment features of HDCD, and detects the Transient Filter flag.
ffmpeg -i HDCD16.flac -af hdcd OUT24.flac
When using the filter with wav, note that the default encoding for wav is 16-bit, so the resulting 20-bit stream will be truncated back to 16-bit ๐ญ. Use something like -acodec pcm_s24le after the filter to get 24-bit PCM output.
ffmpeg -i HDCD16.wav -af hdcd OUT16.wav
ffmpeg -i HDCD16.wav -af hdcd -c:a pcm_s24le OUT24.wav
The filter accepts the following options:
disable_autoconvertโ disable any automatic format conversion or resampling in the filter graph.process_stereoโ Process the stereo channels together. Iftarget_gaindoes not match between channels, consider it invalid and use the last validtarget_gain. ๐cdt_msโ Set the code detect timer period in ms. โฑ๏ธforce_peโ Always extend peaks above-3dBFSeven if PE isnโt signaled. ๐ฅanalyze_modeโ Replace audio with a solid tone and adjust the amplitude to signal some specific aspect of the decoding process. The output file can be loaded in an audio editor alongside the original to aid analysis. ๐ง
"analyze_mode=pe:force_pe=true" can be used to see all samples above the PE level.
The modes are:
0,offโ Disabled1,lleโ Gain adjustment level at each sample2,peโ Samples where peak extend occurs3,cdtโ Samples where the code detect timer is active4,tgmโ Samples where the target gain does not match between channels
๐ง headphone
Apply head-related transfer functions (HRTFs) to create virtual loudspeakers around the user for binaural listening via headphones. The HRIRs are provided via additional streams; for each channel, one stereo input stream is needed. ๐ฆ
The filter accepts the following options:
mapโ Set mapping of input streams for convolution. The argument is a'|'-separated list of channel names in the order they are given as additional stream inputs for the filter. This also specifies the number of input streams. The number of input streams must be not less than the number of channels in the first stream plus one. ๐บ๏ธgainโ Set gain applied to audio. Value is in dB. Default is0. ๐typeโ Set processing type. Can betimeorfreq.timeis processing audio in the time domain, which is slow.freqis processing audio in the frequency domain, which is fast. Default isfreq. โกlfeโ Set custom gain for LFE channels. Value is in dB. Default is0. ๐sizeโ Set size of frame in number of samples which will be processed at once. Default value is1024. Allowed range is from1024to96000. ๐hrirโ Set format of the hrir stream. Default value isstereo. Alternative value ismultich. If the value is set tostereo, the number of additional streams should be greater or equal to the number of input channels in the first input stream. Also, each additional stream should have a stereo number of channels. If the value is set tomultich, the number of additional streams should be exactly one. Also, the number of input channels of the additional stream should be equal or greater than twice the number of channels of the first input stream. ๐
โจ Examples
- Full example using wav files as coefficients with
amoviefilters for 7.1 downmix; eachamoviefilter uses a stereo file with IR coefficients as input. The files give coefficients for each position of the virtual loudspeaker:
ffmpeg -i input.wav
-filter_complex "amovie=azi_270_ele_0_DFC.wav[sr];amovie=azi_90_ele_0_DFC.wav[sl];amovie=azi_225_ele_0_DFC.wav[br];amovie=azi_135_ele_0_DFC.wav[bl];amovie=azi_0_ele_0_DFC.wav,asplit[fc][lfe];amovie=azi_35_ele_0_DFC.wav[fl];amovie=azi_325_ele_0_DFC.wav[fr];[0:a][fl][fr][fc][lfe][bl][br][sl][sr]headphone=FL|FR|FC|LFE|BL|BR|SL|SR"
output.wav
- Full example using wav files as coefficients with
amoviefilters for 7.1 downmix, but now inmultichhrir format:
ffmpeg -i input.wav -filter_complex "amovie=minp.wav[hrirs];[0:a][hrirs]headphone=map=FL|FR|FC|LFE|BL|BR|SL|SR:hrir=multich"
output.wav
๐ธ highpass
Apply a high-pass filter with a 3dB point frequency. The filter can be either single-pole or double-pole (the default). The filter rolls off at 6dB per pole per octave (20dB per pole per decade). ๐ฅ
The filter accepts the following options:
frequency,fโ Set frequency in Hz. Default is3000. ๐ตpoles,pโ Set number of poles. Default is2. ๐งwidth_type,tโ Set method to specify band-width of filter.hโ Hzqโ Q-Factoroโ octavesโ slopekโ kHz
width,wโ Specify the band-width of a filter inwidth_typeunits. Applies only to double-pole filter. The default is0.707qand gives a Butterworth response. ๐mix,mโ How much to use filtered signal in output. Default is1. Range is between0and1. ๐๏ธchannels,cโ Specify which channels to filter; by default all available are filtered. ๐normalize,nโ Normalize biquad coefficients; by default is disabled. Enabling it will normalize magnitude response at DC to0dB. โจtransform,aโ Set transform type of IIR filter.didiitditdiilattsvfzdf
precision,rโ Set precision of filtering.autoโ Pick automatic sample format depending on surround filters.s16โ Always use signed 16-bit.s32โ Always use signed 32-bit.f32โ Always use float 32-bit.f64โ Always use float 64-bit.
block_size,bโ Set block size used for reverse IIR processing. If this value is set to a high enough value (higher than impulse response length truncated when it reaches near zero values), filtering will become linear phase; otherwise, if itโs not big enough, it will just produce nasty artifacts. ๐ญ
Note that filter delay will be exactly this many samples when set to a non-zero value.
๐ Commands
This filter supports the following commands:
frequency,fโ Change highpass frequency. Syntax for the command is: "frequency".width_type,tโ Change highpasswidth_type. Syntax for the command is: "width_type".width,wโ Change highpass width. Syntax for the command is: "width".mix,mโ Change highpass mix. Syntax for the command is: "mix".
๐ซถ join
Join multiple input streams into one multi-channel stream. ๐
It accepts the following parameters:
inputsโ The number of input streams. It defaults to2.channel_layoutโ The desired output channel layout. It defaults tostereo.mapโ Map channels from inputs to output. The argument is a'|'-separated list of mappings, each in theinput_idx.in_channel-out_channelform.input_idxis the 0-based index of the input stream.in_channelcan be either the name of the input channel (e.g.FLfor front left) or its index in the specified input stream.out_channelis the name of the output channel.
The filter will attempt to guess the mappings when they are not specified explicitly. It does so by first trying to find an unused matching input channel and, if that fails, it picks the first unused input channel. ๐ง
Join 3 inputs (with properly set channel layouts):
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
Build a 5.1 output from 6 single-channel streams:
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
out
๐ ladspa
Load a LADSPA (Linux Audio Developer's Simple Plugin API) plugin. ๐ง
To enable compilation of this filter you need to configure FFmpeg with --enable-ladspa.
file,fโ Specifies the name of LADSPA plugin library to load. If the environment variableLADSPA_PATHis defined, the LADSPA plugin is searched in each one of the directories specified by the colon-separated list inLADSPA_PATH; otherwise, in the standard LADSPA paths, which are in this order:HOME/.ladspa/lib/,/usr/local/lib/ladspa/,/usr/lib/ladspa/. ๐plugin,pโ Specifies the plugin within the library. Some libraries contain only one plugin, but others contain many of them. If this is not set, the filter will list all available plugins within the specified library. ๐controls,cโ Set the'|'-separated list of controls, which are zero or more floating point values that determine the behavior of the loaded plugin (for example delay, threshold or gain). Controls need to be defined using the following syntax:c0=value0|c1=value1|c2=value2|..., wherevalueiis the value set on the i-th control. Alternatively, they can also be defined using the following syntax:value0|value1|value2|..., wherevalueiis the value set on the i-th control. Ifcontrolsis set tohelp, all available controls and their valid ranges are printed. ๐๏ธsample_rate,sโ Specify the sample rate, default to44100. Only used if plugin have zero inputs. ๐ถnb_samples,nโ Set the number of samples per channel per each output frame, default is1024. Only used if plugin have zero inputs. ๐ฆduration,dโ Set the minimum duration of the sourced audio. See the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. Note that the resulting duration may be greater than the specified duration, as the generated audio is always cut at the end of a complete frame. If not specified, or the expressed duration is negative, the audio is supposed to be generated forever. Only used if plugin have zero inputs. โณlatency,lโ Enable latency compensation; by default is disabled. Only used if plugin have inputs. ๐ฐ๏ธ
๐ Examples
- List all available plugins within
amp(LADSPA example plugin) library:
ladspa=file=amp
- List all available controls and their valid ranges for
vcf_notchplugin fromVCFlibrary:
ladspa=f=vcf:p=vcf_notch:c=help
- Simulate low quality audio equipment using
Computer Music Toolkit(CMT) plugin library:
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
- Add reverberation to the audio using TAP-plugins (Tom's Audio Processing plugins):
ladspa=file=tap_reverb:tap_reverb
- Generate white noise, with
0.2amplitude:
ladspa=file=cmt:noise_source_white:c=c0=.2
- Generate 20 bpm clicks using plugin
C* Click - Metronomefrom theC* Audio Plugin Suite(CAPS) library:
ladspa=file=caps:Click:c=c1=20'
- Apply
C* Eq10X2 - Stereo 10-band equalisereffect:
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
- Increase volume by 20dB using fast lookahead limiter from Steve Harris
SWH Pluginscollection:
ladspa=fast_lookahead_limiter_1913:fastLookaheadLimiter:20|0|2
- Attenuate low frequencies using Multiband EQ from Steve Harris
SWH Pluginscollection:
ladspa=mbeq_1197:mbeq:-24|-24|-24|0|0|0|0|0|0|0|0|0|0|0|0
- Reduce stereo image using
Narrowerfrom theC* Audio Plugin Suite(CAPS) library:
ladspa=caps:Narrower
- Another white noise, now using "C* Audio Plugin Suite" (CAPS) library:
ladspa=caps:White:.2
- Some fractal noise, using "C* Audio Plugin Suite" (CAPS) library:
ladspa=caps:Fractal:c=c1=1
- Dynamic volume normalization using "VLevel" plugin:
ladspa=vlevel-ladspa:vlevel_mono
๐ฌ Commands
cNโ modify the N-th control value. If the specified value is not valid, it is ignored and the prior one is kept.
๐๏ธ loudnorm
EBU R128 loudness normalization, bestie ๐. It includes both dynamic and linear normalization modes, and it supports both single pass (livestreams, files) and double pass (files) modes. This algorithm can target IL, LRA, and maximum true peak. In dynamic mode, to accurately detect true peaks, the audio stream will be upsampled to 192 kHz. Use the -ar option or the aresample filter to explicitly set an output sample rate โจ.
The filter accepts the following options:
I,iโ set integrated loudness target. Range is-70.0--5.0. Default value is-24.0.LRA,lraโ set loudness range target. Range is1.0-50.0. Default value is7.0.TP,tpโ set maximum true peak. Range is-9.0-+0.0. Default value is-2.0.measured_I,measured_iโ measured IL of input file. Range is-99.0-+0.0.measured_LRA,measured_lraโ measured LRA of input file. Range is0.0-99.0.measured_TP,measured_tpโ measured true peak of input file. Range is-99.0-+99.0.measured_threshโ measured threshold of input file. Range is-99.0-+0.0.offsetโ set offset gain. Gain is applied before the true-peak limiter. Range is-99.0-+99.0. Default is+0.0.linearโ normalize by linearly scaling the source audio.measured_I,measured_LRA,measured_TP, andmeasured_threshmust all be specified. Target LRA shouldn't be lower than source LRA and the change in integrated loudness shouldn't result in a true peak which exceeds the target TP. If any of these conditions aren't met, normalization mode will revert to dynamic. Options aretrueorfalse. Default istrue.dual_monoโ treat mono input files as "dual-mono". If a mono file is intended for playback on a stereo system, its EBU R128 measurement will be perceptually incorrect. If set totrue, this option will compensate for this effect. Multi-channel input files are not affected by this option. Options aretrueorfalse. Default isfalse.print_formatโ set print format for stats. Options aresummary,json, ornone. Default value isnone.stats_fileโ write stats to specified file. Format is controlled byprint_format, which must be set. Specify-to write to standard output. Default is unset.
๐ lowpass
Apply a low-pass filter with 3dB point frequency. The filter can be either single-pole or double-pole (the default). The filter rolls off at 6dB per pole per octave (20dB per pole per decade) ๐.
The filter accepts the following options:
frequency,fโ set frequency in Hz. Default is500.poles,pโ set number of poles. Default is2.width_type,tโ set method to specify band-width of filter.hโ Hzqโ Q-Factoroโ octavesโ slopekโ kHz
width,wโ specify the band-width of a filter inwidth_typeunits. Applies only to double-pole filter. The default is0.707qand gives a Butterworth response.mix,mโ how much to use filtered signal in output. Default is1. Range is between0and1.channels,cโ specify which channels to filter, by default all available are filtered.normalize,nโ normalize biquad coefficients, by default is disabled. Enabling it will normalize magnitude response at DC to0dB.transform,aโ set transform type of IIR filter.didiitditdiilattsvfzdf
precision,rโ set precision of filtering.autoโ pick automatic sample format depending on surround filters.s16โ always use signed 16-bit.s32โ always use signed 32-bit.f32โ always use float 32-bit.f64โ always use float 64-bit.
block_size,bโ set block size used for reverse IIR processing. If this value is set to high enough value (higher than impulse response length truncated when reaches near zero values) filtering will become linear phase otherwise if not big enough it will just produce nasty artifacts.
Note that filter delay will be exactly this many samples when set to non-zero value ๐ญ.
โจ Examples
- Lowpass only LFE channel, it LFE is not present it does nothing:
lowpass=c=LFE
๐ฌ Commands
frequency,fโ change lowpass frequency. Syntax for the command is:frequency.width_type,tโ change lowpasswidth_type. Syntax for the command is:width_type.width,wโ change lowpass width. Syntax for the command is:width.mix,mโ change lowpass mix. Syntax for the command is:mix.
๐ง lv2
Load a LV2 (LADSPA Version 2) plugin ๐๏ธ.
To enable compilation of this filter you need to configure FFmpeg with --enable-lv2.
plugin,pโ specifies the plugin URI. You may need to escape':'.controls,cโ set the'|'separated list of controls which are zero or more floating point values that determine the behavior of the loaded plugin (for example delay, threshold or gain). Ifcontrolsis set tohelp, all available controls and their valid ranges are printed.sample_rate,sโ specify the sample rate, default to44100. Only used if plugin have zero inputs.nb_samples,nโ set the number of samples per channel per each output frame, default is1024. Only used if plugin have zero inputs.duration,dโ set the minimum duration of the sourced audio. See the Time duration section in theffmpeg-utils(1)manual for the accepted syntax.
Note that the resulting duration may be greater than the specified duration, as the generated audio is always cut at the end of a complete frame. If not specified, or the expressed duration is negative, the audio is supposed to be generated forever. Only used if plugin have zero inputs ๐.
โจ Examples
- Apply bass enhancer plugin from Calf:
lv2=p=http\\\\://calf.sourceforge.net/plugins/BassEnhancer:c=amount=2
- Apply vinyl plugin from Calf:
lv2=p=http\\\\://calf.sourceforge.net/plugins/Vinyl:c=drone=0.2|aging=0.5
- Apply bit crusher plugin from ArtyFX:
lv2=p=http\\\\://www.openavproductions.com/artyfx#bitta:c=crush=0.3
๐ฌ Commands
This filter supports all options that are exported by plugin as commands ๐ซถ.
๐๏ธ mcompand
Multiband compress or expand the audio's dynamic range ๐ฅ.
The input audio is divided into bands using 4th order Linkwitz-Riley IIRs. This is akin to the crossover of a loudspeaker, and results in flat frequency response when absent compander action.
It accepts the following parameters:
argsโ this option syntax is:
attack,decay,[attack,decay..] soft-knee points crossover_frequency [delay [initial_volume [gain]]] | attack,decay ...
For explanation of each item refer to compand filter documentation.
๐ pan
Mix channels with specific gain levels. The filter accepts the output channel layout followed by a set of channel definitions.
This filter is also designed to efficiently remap the channels of an audio stream โจ.
The filter accepts parameters of the form: l|outdef|outdef|...
lโ output channel layout or number of channelsoutdefโ output channel specification, of the form:out_name=[gain*]in_name[(+-)[gain*]in_name...]out_nameโ output channel to define, either a channel name (FL,FR, etc.) or a channel number (c0,c1, etc.)gainโ multiplicative coefficient for the channel,1leaving the volume unchangedin_nameโ input channel to use, seeout_namefor details; it is not possible to mix named and numbered input channels
If the = in a channel specification is replaced by <, then the gains for that specification will be renormalized so that the total is 1, thus avoiding clipping noise ๐.
๐ Mixing examples
For example, if you want to down-mix from stereo to mono, but with a bigger factor for the left channel:
pan=1c|c0=0.9*c0+0.1*c1
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and 7-channels surround:
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
Note that ffmpeg integrates a default down-mix (and up-mix) system that should be preferred (see -ac option) unless you have very specific needs.
๐ฆ Remapping examples
The channel remapping will be effective if, and only if:
- gain coefficients are zeroes or ones,
- only one input per channel output,
If all these conditions are satisfied, the filter will notify the user ("Pure channel mapping detected"), and use an optimized and lossless method to do the remapping ๐.
For example, if you have a 5.1 source and want a stereo audio stream by dropping the extra channels:
pan="stereo| c0=FL | c1=FR"
Given the same source, you can also switch front left and front right channels and keep the input channel layout:
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
If the input is a stereo audio stream, you can mute the front left channel (and still keep the stereo channel layout) with:
pan="stereo|c1=c1"
Still with a stereo audio stream input, you can copy the right channel in both front left and right:
pan="stereo| c0=FR | c1=FR"
๐ง replaygain
ReplayGain scanner filter. This filter takes an audio stream as an input and outputs it unchanged. At end of filtering it displays track_gain and track_peak โญ.
The filter accepts the following exported read-only options:
track_gainโ exported track gain in dB at end of stream.track_peakโ exported track peak at end of stream.
๐ resample
Convert the audio sample format, sample rate and channel layout. It is not meant to be used directly ๐ซถ.
๐งต rubberband
Apply time-stretching and pitch-shifting with librubberband ๐ .
To enable compilation of this filter, you need to configure FFmpeg with --enable-librubberband.
The filter accepts the following options:
tempoโ sets the tempo scale factor โจpitchโ sets the pitch scale factor ๐๏ธtransientsโ picks the transients detector. possible values arecrisp,mixed,smoothdetectorโ picks the detector. possible values arecompound,percussive,softphaseโ sets the phase. possible values arelaminar,independentwindowโ sets the processing window size. possible values arestandard,short,longsmoothingโ sets smoothing. possible values areoff,onformantโ enables formant preservation when shift pitching ๐ฆ. possible values areshifted,preservedpitchqโ sets pitch quality. possible values arequality,speed,consistencychannelsโ sets channels. possible values areapart,together
โจ Commands โจ
bestie this filter takes commands too, live, mid-stream, no cap:
tempoโ changes the filter tempo scale factor. syntax for the command is:tempopitchโ changes the filter pitch scale factor. syntax for the command is:pitch
๐๏ธ sidechaincompress
okay so this one is literally the normal compressor's cooler sibling ๐
โ it does all the usual compressor things BUT it can compress the signal it detects using a second input signal. it needs two input streams and hands you back one output stream. the first input stream gets processed depending on the second stream's signal. and then, because it's generous like that, the filtered signal can be filtered again with other filters in later stages of processing. go look at the pan and amerge filters too, iykyk.
the filter accepts these options, and yes i'm listing every single one:
level_inโ sets input gain. default is1. range is between0.015625and64.modeโ sets the mode of compressor operation. can be"upward"or"downward". default is"downward".thresholdโ if a signal of the second stream raises above this level it will affect the gain reduction of the first stream ๐. by default it's0.125. range is between0.00097563and1.ratioโ sets a ratio about which the signal is reduced.1:2means that if the level raised4dBabove the threshold, it will be only2dBabove after the reduction. default is2. range is between1and20.attackโ amount of milliseconds the signal has to rise above the threshold before gain reduction starts. default is20. range is between0.01and2000.releaseโ amount of milliseconds the signal has to fall below the threshold before reduction is decreased again. default is250. range is between0.01and9000.makeupโ sets the amount by how much signal will be amplified after processing. default is1. range is from1to64.kneeโ curves the sharp knee around the threshold so it enters gain reduction more softly ๐ธ. default is2.82843. range is between1and8.linkโ chooses if the"average"level between all channels of the side-chain stream, or the louder ("maximum") channel of the side-chain stream, affects the reduction. default is"average".detectionโ should the exact signal be taken in case of"peak", or an RMS one in case of"rms". default is"rms"which is mainly smoother.level_scโ sets sidechain gain. default is1. range is between0.015625and64.mixโ how much to use the compressed signal in the output. default is1. range is between0and1.
Commands
this filter supports the all above options as commands ๐ซถ (yes, every last one of them).
Examples
- full
ffmpegexample taking 2 audio inputs, 1st input to be compressed depending on the signal of 2nd input and later compressed signal to be merged with 2nd input:
ffmpeg -i main.flac -i sidechain.flac -filter_complex "[1:a]asplit=2[sc][mix];[0:a][sc]sidechaincompress[compr];[compr][mix]amerge"
๐ช sidechaingate
a sidechain gate acts like a normal (wideband) gate but it has the ability to filter the detected signal before sending it to the gain reduction stage โจ. normally a gate uses the full range signal to detect a level above the threshold. like, for example: if you cut all lower frequencies from your sidechain signal, the gate will decrease the volume of your track only if not enough highs appear. with this technique you're able to reduce the resonation of a natural drum, or remove "rumbling" of muted strokes from a heavily distorted guitar ๐ธ๐ฅ. it needs two input streams and returns one output stream. first input stream will be processed depending on the second stream's signal.
the filter accepts the following options:
level_inโ sets input level before filtering. default is1. allowed range is from0.015625to64.modeโ sets the mode of operation. can be"upward"or"downward". default is"downward". if set to"upward"mode, higher parts of the signal will be amplified, expanding dynamic range in the upward direction. otherwise, in case of"downward", lower parts of the signal will be reduced ๐ซก.rangeโ sets the level of gain reduction when the signal is below the threshold. default is0.06125. allowed range is from0to1. setting this to0disables reduction, and then the filter behaves like an expander.thresholdโ if a signal rises above this level the gain reduction is released. default is0.125. allowed range is from0to1.ratioโ sets a ratio about which the signal is reduced. default is2. allowed range is from1to9000.attackโ amount of milliseconds the signal has to rise above the threshold before gain reduction stops. default is20milliseconds. allowed range is from0.01to9000.releaseโ amount of milliseconds the signal has to fall below the threshold before the reduction is increased again. default is250milliseconds. allowed range is from0.01to9000.makeupโ sets amount of amplification of signal after processing. default is1. allowed range is from1to64.kneeโ curves the sharp knee around the threshold so it enters gain reduction more softly. default is2.828427125. allowed range is from1to8.detectionโ chooses if the exact signal should be taken for detection or an RMS-like one. default isrms. can bepeakorrms.linkโ chooses if the average level between all channels, or the louder channel, affects the reduction. default isaverage. can beaverageormaximum.level_scโ sets sidechain gain. default is1. range is from0.015625to64.
Commands
this filter supports the all above options as commands, periodt ๐ .
๐คซ silencedetect
detects silence in an audio stream. that's it, that's the job.
this filter logs a message when it detects that the input audio volume is less than or equal to a noise tolerance value, for a duration greater than or equal to the minimum detected noise duration. the printed times and duration are expressed in seconds โฑ๏ธ.
the lavfi.silence_start or lavfi.silence_start.X metadata key is set on the first frame whose timestamp equals or exceeds the detection duration, and it contains the timestamp of the first frame of the silence.
the lavfi.silence_duration or lavfi.silence_duration.X and lavfi.silence_end or lavfi.silence_end.X metadata keys are set on the first frame after the silence. if mono is enabled, and each channel is evaluated separately, the .X suffixed keys are used, and X corresponds to the channel number ๐
the filter accepts the following options:
noise,nโ sets noise tolerance. can be specified in dB (in case"dB"is appended to the specified value) or as an amplitude ratio. default is-60dB, or0.001.duration,dโ sets silence duration until notification (default is2seconds). see the Time duration section in theffmpeg-utils(1)manual for the accepted syntax ๐mono,mโ processes each channel separately, instead of combined. by default this is disabled.
Examples
- detect 5 seconds of silence with
-50dBnoise tolerance:
silencedetect=n=-50dB:d=5
- complete example with
ffmpegto detect silence with0.0001noise tolerance insilence.mp3:
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
โ๏ธ silenceremove
removes silence from the beginning, middle or end of the audio. the glow-up is real ๐
the filter accepts the following options:
start_periodsโ this value is used to indicate if audio should be trimmed at the beginning of the audio. a value of zero indicates no silence should be trimmed from the beginning. when specifying a non-zero value, it trims audio up until it finds non-silence. normally, when trimming silence from the beginning of audio, thestart_periodswill be1, but it can be increased to higher values to trim all audio up to a specific count of non-silence periods. default value is0.start_durationโ specify the amount of time that non-silence must be detected before it stops trimming audio. by increasing the duration, bursts of noise can be treated as silence and trimmed off ๐. default value is0.start_thresholdโ this indicates what sample value should be treated as silence. for digital audio, a value of0may be fine, but for audio recorded from analog, you may wish to increase the value to account for background noise. can be specified in dB (in case"dB"is appended to the specified value) or as an amplitude ratio. default value is0.start_silenceโ specify max duration of silence at the beginning that will be kept after trimming. default is0, which is equal to trimming all samples detected as silence.start_modeโ specify mode of detection of silence end at start of multi-channel audio. can beanyorall. default isany. withany, any sample from any channel that is detected as non-silence will trigger the end of silence trimming at the start of the audio stream. withall, only if every sample from every channel is detected as non-silence will the end of silence trimming at the start of the audio stream be triggered โ limited usage, ngl ๐ซstop_periodsโ sets the count for trimming silence from the end of audio. when specifying a positive value, it trims audio after it finds the specified silence period. to remove silence from the middle of a file, specify astop_periodsthat is negative ๐. this value is then treated as a positive value and is used to indicate the effect should restart processing as specified bystop_periods, making it suitable for removing periods of silence in the middle of the audio. default value is0.stop_durationโ specify a duration of silence that must exist before audio is not copied any more. by specifying a higher duration, silence that is wanted can be left in the audio. default value is0.stop_thresholdโ the same vibe asstart_thresholdbut for chopping silence off the end of your audio. You can write it in dB (just slap "dB" on the end of the value) or as an amplitude ratio. Default is0.stop_silenceโ how much silence at the end you're allowed to keep after trimming, max duration. Default is0, which literally means "trim every single sample flagged as silence". No crumbs left. ๐ชstop_modeโ sets how silence-start is detected after the start of multi-channel audio. Can beanyorall. Default isall. Withany, any sample from any channel detected as silence triggers the start of silence trimming after the audio stream starts (limited usage, iykyk). Withall, only when every sample from every channel is detected as silence does the trimming kick in.detectionโ sets how silence actually gets detected. Bestie, pick your fighter:avgโ mean of absolute values of samples in the moving window.rmsโ root squared mean of absolute values of samples in the moving window.peakโ maximum of absolute values of samples in the moving window.medianโ median of absolute values of samples in the moving window.ptpโ absolute of max peak to min peak difference of samples in the moving window.devโ standard deviation of values of samples in the moving window.
Default value is "rms".
windowโ set the duration, in seconds, used to calculate the window size in number of samples for detecting silence. Using0effectively disables any windowing and uses only a single sample per channel for silence detection. In that case you may need to also setstart_silenceand/orstop_silenceto nonzero values, plusstart_durationand/orstop_durationto nonzero values too. Default value is0.02. Allowed range is from0to10.timestampโ sets the processing mode of every output audio frame's timestamp. Two moods:writeโ full timestamps rewrite, keeping only the start time for the first output frame.copyโ non-dropped frames keep the same timestamp as the input audio frame.
Default value is "write".
Examples โจ
- The example below shows how this filter can start a recording that doesn't have that awkward delay at the beginning โ you know, the one between pressing record and the actual performance starting:
silenceremove=start_periods=1:start_duration=5:start_threshold=0.02
- Trim all silence from beginning to end where there's more than 1 second of silence in the audio:
silenceremove=stop_periods=-1:stop_duration=1:stop_threshold=-90dB
- Trim all digital silence samples, using peak detection, from beginning to end where there are more than 0 samples of digital silence in the audio and digital silence is detected in all channels at the same positions in the stream:
silenceremove=window=0:detection=peak:stop_mode=all:start_mode=all:stop_periods=-1:stop_threshold=0
- Trim every 2nd encountered silence period from beginning to end where there's more than 1 second of silence per silence period in the audio:
silenceremove=stop_periods=-2:stop_duration=1:stop_threshold=-90dB
- Same as above, but keep a maximum of 0.5 seconds of silence from each trimmed period:
silenceremove=stop_periods=-2:stop_duration=1:stop_threshold=-90dB:stop_silence=0.5
- Same as above, but keep a maximum of 1.5 seconds of silence from the start of the audio:
silenceremove=stop_periods=-2:stop_duration=1:stop_threshold=-90dB:stop_silence=0.5:start_periods=1:start_duration=1:start_silence=1.5:stop_threshold=-90dB
Commands โจ๏ธ
This filter supports some of the above options as commands. Slay. ๐
๐ง sofalizer ๐ง
SOFAlizer uses head-related transfer functions (HRTFs) to create virtual loudspeakers all around you for binaural listening through headphones (audio formats up to 9 channels supported, no cap). The HRTFs live in SOFA files โ peep <http://www.sofacoustics.org/> for a whole database of them. SOFAlizer is developed at the Acoustics Research Institute (ARI) of the Austrian Academy of Sciences. Respect. ๐
To enable compilation of this filter you need to configure FFmpeg with --enable-libmysofa.
The filter accepts the following options:
sofaโ set the SOFA file used for rendering.gainโ set gain applied to audio. Value is in dB. Default is0.rotationโ set rotation of virtual loudspeakers in deg. Default is0.elevationโ set elevation of virtual speakers in deg. Default is0.radiusโ set distance in meters between the loudspeakers and the listener, using near-field HRTFs. Default is1.typeโ set processing type. Can betimeorfreq.timeprocesses audio in the time domain, which is slow ๐.freqprocesses audio in the frequency domain, which is fast โก. Default isfreq.speakersโ set custom positions of virtual loudspeakers. Syntax for this option is:<CH> <AZIM> <ELEV>[|<CH> <AZIM> <ELEV>|...]. Each virtual loudspeaker is described with a short channel name followed by azimuth and elevation in degrees. Each virtual loudspeaker description is separated by'|'. For example, to override the front left and front right channel positions use:'speakers=FL 45 15|FR 345 15'. Descriptions with unrecognised channel names are ignored (they get no attention, periodt).lfegainโ set custom gain for LFE channels. Value is in dB. Default is0.framesizeโ set custom frame size in number of samples. Default is1024. Allowed range is from1024to96000. Only used if optiontypeis set tofreq.normalizeโ should all IRs be normalized upon importing the SOFA file? By default is enabled.interpolateโ should nearest IRs be interpolated with neighbor IRs if the exact position doesn't match? By default is disabled.minphaseโ minphase all IRs upon loading of the SOFA file. By default is disabled.anglestepโ set neighbor search angle step. Only used if optioninterpolateis enabled.radstepโ set neighbor search radius step. Only used if optioninterpolateis enabled.
Examples ๐ฆ
- Using the ClubFritz6 sofa file:
sofalizer=sofa=/path/to/ClubFritz6.sofa:type=freq:radius=1
- Using the ClubFritz12 sofa file and a bigger radius with a small rotation:
sofalizer=sofa=/path/to/ClubFritz12.sofa:type=freq:radius=2:rotation=5
- Similar to above, but with custom speaker positions for front left, front right, back left and back right โ plus custom gain:
"sofalizer=sofa=/path/to/ClubFritz6.sofa:type=freq:radius=2:speakers=FL 45|FR 315|BL 135|BR 225:gain=28"
๐ฃ๏ธ speechnorm ๐ฃ๏ธ
Speech Normalizer. It expands or compresses each half-cycle of audio samples (a local set of samples all above or all below zero, between two nearest zero crossings) depending on the threshold value, so the audio reaches the target peak value under conditions controlled by the options below. Your voice: louder, but make it make sense. ๐คโจ
The filter accepts the following options:
peak,pโ set the expansion target peak value. This specifies the highest allowed absolute amplitude level for the normalized audio input. Default value is0.95. Allowed range is from0.0to1.0.expansion,eโ set the maximum expansion factor. Allowed range is from1.0to50.0. Default value is2.0. This option controls the maximum local half-cycle-of-samples expansion. The maximum expansion would be such that the local peak value reaches the target peak value but never surpasses it, and that the ratio between new and previous peak value doesn't surpass this option value.compression,cโ set the maximum compression factor. Allowed range is from1.0to50.0. Default value is2.0. This option controls the maximum local half-cycle-of-samples compression. It's only used if optionthresholdis set to a value greater than0.0โ then in those cases where the local peak is lower than or the same as the value set bythreshold, all samples belonging to that peak's half-cycle get compressed by the current compression factor.threshold,tโ set the threshold value. Default value is0.0. Allowed range is from0.0to1.0. This option specifies which half-cycles of samples get compressed and which get expanded. Any half-cycle samples whose local peak value is below or the same as this option value get compressed by the current compression factor โ otherwise, if greater than the threshold value, they get expanded with the expansion factor so it could reach the peak target value but never surpass it.raise,rโ set the expansion raising amount per each half-cycle of samples. Default value is0.001. Allowed range is from0.0to1.0. This controls how fast the expansion factor is raised per each new half-cycle until it reaches theexpansionvalue. Setting this option too high may lead to distortions โ highkey be careful. ๐ญfall,fโ set the compression raising amount per each half-cycle of samples. Default value is0.001. Allowed range is from0.0to1.0. This controls how fast the compression factor is raised per each new half-cycle until it reaches thecompressionvalue.channels,hโ specify which channels to filter. By default all available channels are filtered.invert,iโ enable inverted filtering, by default is disabled. This inverts the interpretation of thethresholdoption. When enabled, any half-cycle of samples whose local peak value is below or the same as thethresholdoption gets expanded, otherwise it gets compressed.link,lโ link channels when calculating the gain applied to each filtered channel sample. By default is disabled. When disabled, each filtered channel's gain calculation is independent โ otherwise, when this option is enabled, the minimum of all possible gains for each filtered channel is used.rms,mโ set the expansion target RMS value. This specifies the highest allowed RMS level for the normalized audio input. Default value is0.0, thus disabled. Allowed range is from0.0to1.0.
Commands ๐
This filter supports all of the above options as commands. All of them. Iconic. ๐
Examples ๐
- Weak and slow amplification:
speechnorm=e=3:r=0.00001:l=1
- Moderate and slow amplification:
speechnorm=e=6.25:r=0.00001:l=1
- Strong and fast amplification:
speechnorm=e=12.5:r=0.0001:l=1
- Very strong and fast amplification:
speechnorm=e=25:r=0.0001:l=1
- Extreme and fast amplification:
speechnorm=e=50:r=0.0001:l=1
๐ stereotools
Okay bestie, this filter is literally the Swiss Army knife of stereo. It's got all these handy lil utilities for managing stereo signals โ converting M/S stereo recordings to L/R signal while you keep full control over the parameters, or spreading out the stereo image of your master track. Iconic.
The filter accepts the following options:
level_inโ sets the input level before filtering, for both channels. Default is1. Allowed range is from0.015625to64.level_outโ sets the output level after filtering, for both channels. Default is1. Allowed range is from0.015625to64.balance_inโ sets the input balance between both channels. Default is0. Allowed range is from-1to1.balance_outโ sets the output balance between both channels. Default is0. Allowed range is from-1to1.softclipโ enables softclipping. It gives you analog distortion instead of that harsh digital 0dB clipping. Disabled by default.mutelโ mutes the left channel. Disabled by default.muterโ mutes the right channel. Disabled by default.phaselโ changes the phase of the left channel. Disabled by default.phaserโ changes the phase of the right channel. Disabled by default.modeโ sets the stereo mode. The available values are:lr>lrโ Left/Right to Left/Right, this is the default one.lr>msโ Left/Right to Mid/Side.ms>lrโ Mid/Side to Left/Right.lr>llโ Left/Right to Left/Left.lr>rrโ Left/Right to Right/Right.lr>l+rโ Left/Right to Left + Right.lr>rlโ Left/Right to Right/Left.ms>llโ Mid/Side to Left/Left.ms>rrโ Mid/Side to Right/Right.ms>rlโ Mid/Side to Right/Left.lr>l-rโ Left/Right to Left - Right.
slevโ sets the level of the side signal. Default is1. Allowed range is from0.015625to64.sbalโ sets the balance of the side signal. Default is0. Allowed range is from-1to1.mlevโ sets the level of the middle signal. Default is1. Allowed range is from0.015625to64.mpanโ sets the middle signal pan. Default is0. Allowed range is from-1to1.baseโ sets the stereo base between mono and inversed channels. Default is0. Allowed range is from-1to1.delayโ sets the delay in milliseconds, like how much to delay left from right channel and vice versa. Default is0. Allowed range is from-20to20.sclevelโ sets the S/C level. Default is1. Allowed range is from1to100.phaseโ sets the stereo phase in degrees. Default is0. Allowed range is from0to360.bmode_in,bmode_outโ sets the balance mode for thebalance_in/balance_outoption. Can be one of the following:balanceโ classic balance mode. Attenuate one channel at time. Gain is raised up to1.amplitudeโ similar as the classic mode above, but the gain is raised up to2.powerโ equal power distribution, from-6dBto+6dBrange.
๐ฌ Commands
This filter supports all of the above options as commands. Slay.
๐ Examples
- Apply a karaoke like effect:
stereotools=mlev=0.015625
- Convert M/S signal to L/R:
"stereotools=mode=ms>lr"
๐ฆ stereowiden
This filter enhances the stereo effect by suppressing the signal that's common to both channels, and by delaying the left signal into the right and vice versa โ which widens the stereo effect. It's giving main character energy, fr.
The filter accepts the following options:
delayโ time in milliseconds of the delay of left signal into right and vice versa. Default is20milliseconds.feedbackโ amount of gain in the delayed signal into right and vice versa. It gives a delay effect of the left signal in the right output and vice versa, which gives that widening effect. Default is0.3.crossfeedโ cross feed of left into right with inverted phase. This helps in suppressing the mono. If the value is1it will cancel all the signal common to both channels. Default is0.3.drymixโ sets the level of the input signal of the original channel. Default is0.8.
๐ฌ Commands
This filter supports all of the above options except delay as commands. Yeah, that one's not invited to the command party ๐.
โจ superequalizer
Apply an 18 band equalizer. Eighteen. Bands. Obsessed.
The filter accepts the following options:
1bโ set the65Hzband gain.2bโ set the92Hzband gain.3bโ set the131Hzband gain.4bโ set the185Hzband gain.5bโ set the262Hzband gain.6bโ set the370Hzband gain.7bโ set the523Hzband gain.8bโ set the740Hzband gain.9bโ set the1047Hzband gain.10bโ set the1480Hzband gain.11bโ set the2093Hzband gain.12bโ set the2960Hzband gain.13bโ set the4186Hzband gain.14bโ set the5920Hzband gain.15bโ set the8372Hzband gain.16bโ set the11840Hzband gain.17bโ set the16744Hzband gain.18bโ set the20000Hzband gain.
๐ surround
Apply the audio surround upmix filter. This filter lets you produce multichannel output from an audio stream. Glow-up for your stereo, honestly.
The filter accepts the following options:
chl_outโ sets the output channel layout. By default, this is5.1. See the Channel Layout section in theffmpeg-utils(1)manual for the required syntax.chl_inโ sets the input channel layout. By default, this isstereo. See the Channel Layout section in theffmpeg-utils(1)manual for the required syntax.level_inโ sets the input volume level. By default, this is1.level_outโ sets the output volume level. By default, this is1.lfeโ enable LFE channel output if the output channel layout has it. By default, this is enabled.lfe_lowโ sets the LFE low cut off frequency. By default, this is128Hz.lfe_highโ sets the LFE high cut off frequency. By default, this is256Hz.lfe_modeโ sets the LFE mode, can beaddorsub. Default isadd. Inaddmode, the LFE channel is created from the input audio and added to the output. Insubmode, the LFE channel is created from the input audio and added to the output, but also all non-LFE output channels are subtracted with the output LFE channel.smoothโ sets the temporal smoothness strength, used to gradually change factors when transforming stereo sound in time. Allowed range is from0.0to1.0. Useful to improve output quality withfocusoption values greater than0.0. Default is0.0. Only values inside this range and without edges are effective.angleโ sets the angle of the stereo surround transform. Allowed range is from0to360. Default is90.focusโ sets the focus of the stereo surround transform. Allowed range is from-1to1. Default is0.fc_inโ sets the front center input volume. By default, this is1.fc_outโ sets the front center output volume. By default, this is1.fl_inโ sets the front left input volume. By default, this is1.fl_outโ sets the front left output volume. By default, this is1.fr_inโ sets the front right input volume. By default, this is1.fr_outโ sets the front right output volume. By default, this is1.sl_inโ sets the side left input volume. By default, this is1.sl_outโ sets the side left output volume. By default, this is1.sr_inโ sets the side right input volume. By default, this is1.sr_outโ sets the side right output volume. By default, this is1.bl_inโ sets the back left input volume. By default, this is1.bl_outโ sets the back left output volume. By default, this is1.br_inโ sets the back right input volume. By default, this is1.br_outโ sets the back right output volume. By default, this is1.bc_inโ sets the back center input volume. By default, this is1.bc_outโ sets the back center output volume. By default, this is1.lfe_inโ sets the LFE input volume. By default, this is1.lfe_outโ sets the LFE output volume. By default, this is1.allxโ sets spread usage of the stereo image across the X axis, for all channels. Allowed range is from-1to15. By default this value is negative-1, and thus unused.allyโ sets spread usage of the stereo image across the Y axis, for all channels. Allowed range is from-1to15. By default this value is negative-1, and thus unused.fcx,flx,frx,blx,brx,slx,srx,bcxโ set spread usage of the stereo image across the X axis for each channel. Allowed range is from0.06to15. By default this value is0.5.fcy,fly,fry,bly,bry,sly,sry,bcyโ set spread usage of the stereo image across the Y axis for each channel. Allowed range is from0.06to15. By default this value is0.5.win_sizeโ sets the window size. Allowed range is from1024to65536. Default size is4096.win_funcโ sets the window function. It accepts the following values:
rect
bartlett
hann, hanning
hamming
blackman
welch
flattop
bharris
bnuttall
bhann
sine
nuttall
lanczos
gauss
tukey
dolph
cauchy
parzen
poisson
bohman
kaiser
Default is "hann".
overlapโ sets the window overlap. If set to1, the recommended overlap for the selected window function will be picked. Default is0.5.
๐ tiltshelf
Boost or cut the lower frequencies, and cut or boost the higher frequencies of the audio, using a two-pole shelving filter with a response similar to that of a standard hi-fi's tone-controls. This is also known as shelving equalisation (EQ). Vintage but make it cute ๐ .
The filter accepts the following options:
gain,gโ give the gain at0Hz. Its useful range is about-20(for a large cut) to+20(for a large boost). Beware of clipping when using a positive gain โ fr fr, watch out for that.frequency,fโ set the filter's central frequency, so it can be used to extend or reduce the frequency range to be boosted or cut. The default value is3000Hz.width_type,tโ set the method to specify the band-width of the filter.hโ Hzqโ Q-Factoroโ octavesโ slopekโ kHz
width,wโ determine how steep the filter's shelf transition is.poles,pโ set the number of poles. Default is2.mix,mโ how much to use the filtered signal in the output. Default is1. Range is between0and1.channels,cโ specify which channels to filter; by default all available are filtered.normalize,nโ normalize the biquad coefficients. By default is disabled. Enabling it will normalize the magnitude response at DC to0dB.transform,aโ set the transform type of the IIR filter.
di
dii
tdi
tdii
latt
svf
zdf
precision,rโ sets the precision of the filtering, bestie. pick your sample format:autoโ picks the sample format automatically, based on the surround filters ๐s16โ always signed 16-bit, no caps32โ always signed 32-bitf32โ always float 32-bitf64โ always float 64-bit
block_size,bโ sets the block size used for reverse IIR processing. and listen: if you set this high enough (higher than the impulse response length, truncated when it reaches near-zero values) the filtering goes linear phase โจ โ but if it's not big enough it'll just produce nasty artifacts ๐ญ fr fr.
heads up: when this is set to a non-zero value, the filter delay will be exactly this many samples. like, exactly. ๐ซถ
Commands
this filter supports some options as commands ๐
๐ธ treble, highshelf ๐ธ
boosts or cuts the treble (upper) frequencies of the audio, using a two-pole shelving filter with a response similar to a standard hi-fi's tone-controls. this is also known as shelving equalisation (EQ), iykyk ๐
the filter accepts these options:
gain,gโ gives you the gain at whichever is the lower of ~22 kHz and the Nyquist frequency. useful range is like -20 (big cut) to +20 (big boost). โ ๏ธ beware of clipping when you use a positive gain, okay?frequency,fโ sets the filter's central frequency, so you can extend or reduce the frequency range that gets boosted or cut. default value is3000Hz.width_type,tโ sets the method used to specify the band-width of the filter:hโ Hzqโ Q-Factoroโ octavesโ slopekโ kHz
width,wโ determines how steep the filter's shelf transition is ๐poles,pโ sets the number of poles. default is2.mix,mโ how much of the filtered signal goes into the output. default is1. range is between0and1.channels,cโ specifies which channels to filter. by default all available channels get filtered ๐normalize,nโ normalizes the biquad coefficients; by default it's disabled. turning it on normalizes the magnitude response at DC to 0dB. slay.transform,aโ sets the transform type of the IIR filter:didiitditdiilattsvfzdf
precision,rโ sets the precision of filtering:autoโ picks the automatic sample format depending on the surround filterss16โ always use signed 16-bits32โ always use signed 32-bitf32โ always use float 32-bitf64โ always use float 64-bit
block_size,bโ sets the block size used for reverse IIR processing. set it high enough (higher than the impulse response length, truncated when it reaches near-zero values) and the filtering becomes linear phase โจ; if it's not big enough it just produces nasty artifacts ๐ญ
note: the filter delay will be exactly this many samples when set to a non-zero value. same deal as before, bestie.
Commands
this filter supports these commands:
frequency,fโ change treble frequency. syntax for the command is:"frequency"width_type,tโ change treble width_type. syntax for the command is:"width_type"width,wโ change treble width. syntax for the command is:"width"gain,gโ change treble gain. syntax for the command is:"gain"mix,mโ change treble mix. syntax for the command is:"mix"
๐ฆ tremolo ๐ฆ
sinusoidal amplitude modulation โ literally the wobble filter ๐
the filter accepts these options:
fโ modulation frequency in Hertz. modulation frequencies in the subharmonic range (20 Hz or lower) give you a tremolo effect. you can also use this filter as a ring modulator by specifying a modulation frequency higher than 20 Hz โจ range is0.1-20000.0. default value is5.0Hz.dโ depth of modulation as a percentage. range is0.0-1.0. default value is0.5.
๐ vibrato ๐
sinusoidal phase modulation. the sibling of tremolo, ok?
the filter accepts these options:
fโ modulation frequency in Hertz. range is0.1-20000.0. default value is5.0Hz.dโ depth of modulation as a percentage. range is0.0-1.0. default value is0.5.
๐ฅ virtualbass ๐ฅ
applies the audio Virtual Bass filter. it takes stereo input and produces stereo with LFE (2.1) channels on the output ๐
the newly produced LFE channel has enhanced virtual bass, originally obtained from both stereo channels. this filter outputs the front left and front right channels unchanged, exactly as they were in the stereo input โ not me preserving your mains, fr fr ๐
the filter accepts these options:
cutoffโ sets the virtual bass cutoff frequency. default value is250Hz. allowed range is from100to500Hz.strengthโ sets the virtual bass strength. allowed range is from0.5to3. default value is3.
โญ volume โญ
adjusts the input audio volume. main character filter, honestly ๐
it accepts these parameters:
volumeโ sets the audio volume expression.
output values are clipped to the maximum value.
the output audio volume is given by this relation:
<output_volume> = <volume> * <input_volume>
the default value for volume is "1.0".
precisionโ this parameter represents the mathematical precision ๐งฎ
it determines which input sample formats will be allowed, which affects the precision of the volume scaling:
fixedโ 8-bit fixed-point; this limits input sample format toU8,S16, andS32.floatโ 32-bit floating-point; this limits input sample format toFLT. (default)doubleโ 64-bit floating-point; this limits input sample format toDBL.
replaygainโ chooses the behaviour when it encounters ReplayGain side data in input frames:dropโ removes ReplayGain side data, ignoring its contents (the default).ignoreโ ignores ReplayGain side data, but leaves it in the frame.trackโ prefers the track gain, if present.albumโ prefers the album gain, if present.
replaygain_preampโ pre-amplification gain in dB to apply to the selected replaygain gain. default value forreplaygain_preampis0.0.replaygain_noclipโ prevents clipping by limiting the gain applied. default value forreplaygain_noclipis1.evalโ sets when the volume expression is evaluated. it accepts these values:onceโ only evaluates the expression once during filter initialization, or when thevolumecommand is sentframeโ evaluates the expression for each incoming frame
default value is once.
the volume expression can contain these parameters:
nโ frame number (starting at zero)nb_channelsโ number of channelsnb_consumed_samplesโ number of samples consumed by the filternb_samplesโ number of samples in the current frameposโ original frame position in the file; deprecated, do not use ๐ptsโ frame PTSsample_rateโ sample ratestartptsโ PTS at start of streamstarttโ time at start of streamtโ frame timetbโ timestamp timebasevolumeโ last set volume value
important, bestie: whenevalis set toonce, only thesample_rateandtbvariables are available โ all the other variables will evaluate toNAN. ๐ญ don't say i didn't warn you.
Commands
this filter supports these commands:
volumeโ modifies the volume expression. the command accepts the same syntax as the corresponding option.
if the specified expression isn't valid, it's kept at its current value.
Examples
- halve the input audio volume:
volume=volume=0.5
volume=volume=1/2
volume=volume=-6.0206dB
in all the above examples the named key for volume can be omitted, like this:
volume=0.5
- increase input audio power by 6 decibels using fixed-point precision:
volume=volume=6dB:precision=fixed
- fade volume after time 10 with an annihilation period of 5 seconds:
volume='if(lt(t,10),1,max(1-(t-10)/5,0))':eval=frame
๐ volumedetect ๐
detects the volume of the input video. yes, video โ that's what it says ๐
the filter has no parameters. it supports only 16-bit signed integer samples, so the input gets converted when needed. statistics about the volume get printed in the log when the input stream end is reached โจ
in particular it'll show you the mean volume (root mean square), the maximum volume (on a per-sample basis), and the beginning of a histogram of the registered volume values (from the maximum value to a cumulated 1/1000 of the samples).
all volumes are in decibels relative to the maximum PCM value ๐
Examples
here's an excerpt of the output:
[Parsed_volumedetect_0 0xa23120] mean_volume: -27 dB
[Parsed_volumedetect_0 0xa23120] max_volume: -4 dB
[Parsed_volumedetect_0 0xa23120] histogram_4db: 6
[Parsed_volumedetect_0 0xa23120] histogram_5db: 62
[Parsed_volumedetect_0 0xa23120] histogram_6db: 286
[Parsed_volumedetect_0 0xa23120] histogram_7db: 1042
[Parsed_volumedetect_0 0xa23120] histogram_8db: 2551
[Parsed_volumedetect_0 0xa23120] histogram_9db: 4609
[Parsed_volumedetect_0 0xa23120] histogram_10db: 8409
it means that:
- the mean square energy is approximately -27 dB, or 10^-2.7.
- the largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
- there are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
in other words, raising the volume by +4 dB doesn't cause any clipping, raising it by +5 dB causes clipping for 6 samples, etc. ๐
๐ง whisper ๐ง
it runs automatic speech recognition using the OpenAI's Whisper model ๐
it requires the whisper.cpp library (https://github.com/ggml-org/whisper.cpp) as a prerequisite. after installing the library it can be enabled using: ./configure --enable-whisper. slay.
the filter has these options:
modelโ the file path of the downloaded whisper.cpp model (mandatory). like, you literally can't skip it ๐languageโ the language to use for transcription ('auto'for auto-detect). default value:"auto"queueโ the maximum size that will be queued into the filter before processing the audio with whisper, bestie. Using a small value means the audio stream gets processed more often, but the transcription quality will be lower and the required processing power will be higher. Using a large value (e.g.10-20s) produces more accurate results using less CPU (as using thewhisper-clitool), but the transcription latency will be higher, so itโs not useful to process real-time streams. Consider using thevad_modeloption associated with a large queue value. Default value:"3"use_gpuโ if GPU support should be enabled. Default value:"true"gpu_deviceโ the GPU device index to use. Default value:"0"destinationโ if set, the transcription output will be sent to the specified file or URL (use one of the FFmpeg AVIO protocols); otherwise, the output will be logged as info messages. The output will also be set in the"lavfi.whisper.text"frame metadata. If the destination is a file and it already exists, it will be overwritten. ๐formatโ the destination format string; it could be"text"(only the transcribed text will be sent to the destination),"srt"(subtitle format) or"json". Default value:"text"max_lenโ maximum segment length in characters. When set to a value greater than0, transcription segments will be split to not exceed this length. This is useful for generating subtitles with shorter lines. Default value:"0"vad_modelโ path to the VAD model file. If set, the filter will load an additional voice activity detection module (https://github.com/snakers4/silero-vad) that will be used to fragment the audio queue; use this option setting a valid path obtained from the whisper.cpp repository (e.g."../whisper.cpp/models/ggml-silero-v5.1.2.bin") and increase thequeueparameter to a higher value (e.g.20).vad_thresholdโ the VAD threshold to use. Default value:"0.5"vad_min_speech_durationโ the minimum VAD speaking duration. Default value:"0.1"vad_min_silence_durationโ the minimum VAD silence duration. Default value:"0.5"
โจ Examples โจ
- ๐ Run a transcription with srt file generation:
ffmpeg -i input.mp4 -vn -af "whisper=model=../whisper.cpp/models/ggml-base.en.bin\
:language=en\
:queue=3\
:destination=output.srt\
:format=srt" -f null -
- ๐ Run a transcription and send the output in JSON format to an HTTP service:
ffmpeg -i input.mp4 -vn -af "whisper=model=../whisper.cpp/models/ggml-base.en.bin\
:language=en\
:queue=3\
:destination=http\\://localhost\\:3000\
:format=json' -f null -
- ๐ Transcribe the microphone input using the VAD option:
ffmpeg -loglevel warning -f pulse -i default \
-af 'highpass=f=200,lowpass=f=3000,whisper=model=../whisper.cpp/models/ggml-medium.bin\
:language=en\
:queue=10\
:destination=-\
:format=json\
:vad_model=../whisper.cpp/models/ggml-silero-v5.1.2.bin' -f null -
๐ธ AUDIO SOURCES ๐ธ
Okay bestie, hereโs the description of the currently available audio sources. ๐งโจ
๐ง abuffer ๐ง
Buffer audio frames, and make them available to the filter chain.
This source is mainly intended for a programmatic use, in particular through the interface defined in libavfilter/buffersrc.h.
It accepts the following parameters:
time_baseโ the timebase which will be used for timestamps of submitted frames. It must be either a floating-point number or in numerator/denominator form.sample_rateโ the sample rate of the incoming audio buffers.sample_fmtโ the sample format of the incoming audio buffers. Either a sample format name or its corresponding integer representation from theenum AVSampleFormatinlibavutil/samplefmt.h.channel_layoutโ the channel layout of the incoming audio buffers. Either a channel layout name fromchannel_layout_mapinlibavutil/channel_layout.cor its corresponding integer representation from theAV_CH_LAYOUT_*macros inlibavutil/channel_layout.h.channelsโ the number of channels of the incoming audio buffers. If bothchannelsandchannel_layoutare specified, then they must be consistent.
๐ Examples ๐
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
will instruct the source to accept planar 16bit signed stereo at 44100Hz. Since the sample format with name "s16p" corresponds to the number 6 and the "stereo" channel layout corresponds to the value 0x3, this is equivalent to:
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
๐ aevalsrc ๐
Generate an audio signal specified by an expression.
This source accepts in input one or more expressions (one for each channel), which are evaluated and used to generate a corresponding audio signal.
This source accepts the following options:
exprsโ set the'|'-separated expressions list for each separate channel. In case thechannel_layoutoption is not specified, the selected channel layout depends on the number of provided expressions. Otherwise the last specified expression is applied to the remaining output channels.channel_layout,cโ set the channel layout. The number of channels in the specified layout must be equal to the number of specified expressions.duration,dโ set the minimum duration of the sourced audio. See the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. Note that the resulting duration may be greater than the specified duration, as the generated audio is always cut at the end of a complete frame.
If not specified, or the expressed duration is negative, the audio is supposed to be generated forever.
nb_samples,nโ set the number of samples per channel per each output frame, default to1024.sample_rate,sโ specify the sample rate, default to44100.
Each expression in exprs can contain the following constants:
nโ number of the evaluated sample, starting from0tโ time of the evaluated sample expressed in seconds, starting from0sโ sample rate
๐ Examples ๐
- Generate silence:
aevalsrc=0
- Generate a sin signal with frequency of 440 Hz, set sample rate to 8000 Hz:
aevalsrc="sin(440*2*PI*t):s=8000"
- Generate a two channels signal, specify the channel layout (Front Center + Back Center) explicitly:
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
- Generate white noise:
aevalsrc="-2+random(0)"
- Generate an amplitude modulated signal:
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
- Generate 2.5 Hz binaural beats on a 360 Hz carrier:
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
๐ฆ afdelaysrc ๐ฆ
Generate a fractional delay FIR coefficients.
The resulting stream can be used with afir filter for filtering the audio signal.
The filter accepts the following options:
delay,dโ set the fractional delay. Default is0.sample_rate,rโ set the sample rate, default is44100.nb_samples,nโ set the number of samples per each frame. Default is1024.taps,tโ set the number of filter coefficients in output audio stream. Default value is0.channel_layout,cโ specifies the channel layout, and can be a string representing a channel layout. The default value ofchannel_layoutis"stereo".
๐ afireqsrc ๐
Generate a FIR equalizer coefficients.
The resulting stream can be used with afir filter for filtering the audio signal.
The filter accepts the following options:
preset,pโ set equalizer preset. Default preset is"flat".
Available presets are:
customflatacousticbassbeatsclassiccleardeep bassdubstepelectronichard-stylehip-hopjazzmetalmoviepopr&brockvocal booster
gains,gโ set custom gains for each band. Only used if thepresetoption is set to"custom". Gains are separated by white spaces and each gain is set in dBFS. Default is"0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0".bands,bโ set the custom bands from where custom equalizer gains are set. This must be in strictly increasing order. Only used if thepresetoption is set to"custom". Bands are separated by white spaces and each band represent frequency in Hz. Default is"25 40 63 100 160 250 400 630 1000 1600 2500 4000 6300 10000 16000 24000".taps,tโ set number of filter coefficients in output audio stream. Default value is4096.sample_rate,rโ set sample rate of output audio stream, default is44100.nb_samples,nโ set number of samples per each frame in output audio stream. Default is1024.interp,iโ set interpolation method for FIR equalizer coefficients. Can be"linear"or"cubic".phase,hโ set phase type of FIR filter. Can be"linear"or"min": minimum-phase. Default is minimum-phase filter.
๐ afirsrc ๐
Generate a FIR coefficients using frequency sampling method.
The resulting stream can be used with afir filter for filtering the audio signal.
The filter accepts the following options:
taps,tโ set number of filter coefficients in output audio stream. Default value is1025.frequency,fโ set frequency points from where magnitude and phase are set. This must be in non decreasing order, and first element must be0, while last element must be1. Elements are separated by white spaces.magnitude,mโ set magnitude value for every frequency point set byfrequency. Number of values must be same as number of frequency points. Values are separated by white spaces.phase,pโ set phase value for every frequency point set byfrequency. Number of values must be same as number of frequency points. Values are separated by white spaces.sample_rate,rโ set sample rate, default is44100.nb_samples,nโ set number of samples per each frame. Default is1024.win_func,wโ set window function. Default isblackman.
anullsrc ๐ซง
okay so this one is the null audio source โ it just hands you back unprocessed audio frames, like, it does nothing but it does it flawlessly ๐
. it's mainly useful as a template, and for analysis / debugging tools, or as the source for filters that literally ignore the input data (the sox synth filter is the classic example, iykyk).
This source accepts the following options:
channel_layout,clโ tells it the channel layout, and ngl it can be either an integer or a string representing a channel layout. the default value ofchannel_layoutis"stereo". and bestie, check thechannel_layout_mapdefinition inlibavutil/channel_layout.cfor the mapping between strings and channel layout values ๐sample_rate,rโ sets the sample rate, defaults to44100.nb_samples,nโ sets the number of samples per requested frames.duration,dโ sets the duration of the sourced audio. peep the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. if it's not specified, or the expressed duration is negative, the audio is supposed to be generated forever โพ๏ธ
Examples โจ
- set the sample rate to 48000 Hz and the channel layout to
AV_CH_LAYOUT_MONO:
anullsrc=r=48000:cl=4
- do the same operation with a more obvious syntax:
anullsrc=r=48000:cl=mono
All the parameters need to be explicitly defined. no vibes-based defaults here, bestie ๐
flite ๐ฃ๏ธ
synthesize a voice utterance using the libflite library. literally a whole text-to-speech moment ๐ธ
to enable compilation of this filter you need to configure FFmpeg with --enable-libflite.
heads up: versions of the flite library prior to 2.0 are not thread-safe ๐ญ
The filter accepts the following options:
list_voicesโ if set to1, it lists the names of the available voices and exits immediately. default value is0.nb_samples,nโ sets the maximum number of samples per frame. default value is512.textfileโ sets the filename containing the text to speak.textโ sets the text to speak.voice,vโ sets the voice to use for the speech synthesis. default value is"kal". see also thelist_voicesoption ๐
Examples ๐
- read from file
speech.txt, and synthesize the text using the standardflitevoice:
flite=textfile=speech.txt
- read the specified text selecting the
"slt"voice:
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- input text to
ffmpeg:
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- make
ffplayspeak the specified text, using"flite"and the"lavfi"device:
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
for more information about libflite, check: http://www.festvox.org/flite/ ๐ฆ
anoisesrc ๐
generate a noise audio signal. yes, noise. on purpose. it's giving static TV at 3am ๐บโจ
The filter accepts the following options:
sample_rate,rโ specify the sample rate. default value is48000Hz.amplitude,aโ specify the amplitude (0.0 - 1.0) of the generated audio stream. default value is1.0.duration,dโ specify the duration of the generated audio stream. not specifying this option results in noise with an infinite length โพ๏ธcolor,colour,cโ specify the color of noise. available noise colors arewhite,pink,brown,blue,violetandvelvet. default color iswhite.seed,sโ specify a value used to seed the PRNG.nb_samples,nโ sets the number of samples per each output frame, default is1024.densityโ sets the density (0.0 - 1.0) for the velvet noise generator, default is0.05.
Examples ๐
- generate 60 seconds of pink noise, with a 44.1 kHz sampling rate and an amplitude of 0.5:
anoisesrc=d=60:c=pink:r=44100:a=0.5
hilbert ๐
generate odd-tap Hilbert transform FIR coefficients.
the resulting stream can be used with the afir filter for phase-shifting the signal by 90 degrees. this is used in many matrix coding schemes and for analytic signal generation. the process is often written as a multiplication by i (or j), the imaginary unit. math girlies rise ๐ง
The filter accepts the following options:
sample_rate,sโ sets sample rate, default is44100.taps,tโ sets length of FIR filter, default is22051.nb_samples,nโ sets number of samples per each frame.win_func,wโ sets window function to be used when generating FIR coefficients.
sinc ๐
generate a sinc kaiser-windowed low-pass, high-pass, band-pass, or band-reject FIR coefficients. all the flavors, one filter, we love versatility ๐
the resulting stream can be used with the afir filter for filtering the audio signal.
The filter accepts the following options:
sample_rate,rโ sets sample rate, default is44100.nb_samples,nโ sets number of samples per each frame. default is1024.hpโ sets high-pass frequency. default is0.lpโ sets low-pass frequency. default is0. if high-pass frequency is lower than low-pass frequency and low-pass frequency is higher than0then the filter will create band-pass filter coefficients, otherwise band-reject filter coefficients. sneaky logic but ok ๐phaseโ sets filter phase response. default is50. allowed range is from0to100.betaโ sets Kaiser window beta.attโ sets stop-band attenuation. default is120dB, allowed range is from40to180dB.roundโ enable rounding, by default is disabled.hptapsโ sets number of taps for high-pass filter.lptapsโ sets number of taps for low-pass filter.
sine ๐ต
generate an audio signal made of a sine wave with amplitude 1/8. and bestie โ the audio signal is bit-exact. flawless. no notes. โญ
The filter accepts the following options:
frequency,fโ sets the carrier frequency. default is440Hz.beep_factor,bโ enable a periodic beep every second with frequencybeep_factortimes the carrier frequency. default is0, meaning the beep is disabled.sample_rate,rโ specify the sample rate, default is44100.duration,dโ specify the duration of the generated audio stream.samples_per_frameโ sets the number of samples per output frame. the expression can contain the following constants:nโ the (sequential) number of the output audio frame, starting from0.ptsโ the PTS (Presentation TimeStamp) of the output audio frame, expressed inTBunits.tโ the PTS of the output audio frame, expressed in seconds.TBโ the timebase of the output audio frames.
default is 1024.
Examples ๐
- generate a simple 440 Hz sine wave:
sine
- generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
sine=220:4:d=5
sine=f=220:b=4:d=5
sine=frequency=220:beep_factor=4:duration=5
- generate a 1 kHz sine wave following
"1602,1601,1602,1601,1602"NTSC pattern:
sine=1000:samples_per_frame='st(0,mod(n,5)); 1602-not(not(eq(ld(0),1)+eq(ld(0),3)))'
๐ง AUDIO SINKS ๐ง
below is a description of the currently available audio sinks. they're the end of the line, the final boss of the filter chain ๐
abuffersink ๐ซถ
buffer audio frames, and make them available to the end of the filter chain.
this sink is mainly intended for programmatic use, in particular through the interface defined in libavfilter/buffersink.h or the options system. it accepts a pointer to an AVABufferSinkContext structure, which defines the incoming buffers' formats, to be passed as the opaque parameter to avfilter_init_filter for initialization.
anullsink ๐ถ
null audio sink; does absolutely nothing with the input audio. it is mainly useful as a template and for use in analysis / debugging tools. iconic behaviour honestly โ shows up, does nothing, leaves ๐
๐ฌ VIDEO FILTERS ๐ฌ
when you configure your FFmpeg build, you can disable any of the existing filters using --disable-filters. the configure output will show the video filters included in your build. bestie check your build list, don't come crying when your filter is missing ๐ญ
below is a description of the currently available video filters.
addroi ๐ฏ
mark a region of interest in a video frame.
the frame data is passed through unchanged, but metadata is attached to the frame indicating regions of interest which can affect the behaviour of later encoding. multiple regions can be marked by applying the filter multiple times. lowkey the main character of "i'm not touching your pixels, i'm just leaving notes" ๐
xโ region distance in pixels from the left edge of the frame.yโ region distance in pixels from the top edge of the frame.wโ region width in pixels.hโ region height in pixels.
the parameters x, y, w and h are expressions, and may contain the following variables:
iwโ width of the input frame.ihโ height of the input frame.
qoffsetโ quantisation offset to apply within the region. this must be a real value in the range-1to+1. a value of zero indicates no quality change. a negative value asks for better quality (less quantisation), while a positive value asks for worse quality (greater quantisation).
the range is calibrated so that the extreme values indicate the largest possible offset โ if the rest of the frame is encoded with the worst possible quality, an offset of -1 indicates that this region should be encoded with the best possible quality anyway. intermediate values are then interpolated in some codec-dependent way.
for example, in 10-bit H.264 the quantisation parameter varies between -12 and 51. a typical qoffset value of -1/10 therefore indicates that this region should be encoded with a QP around one-tenth of the full range better than the rest of the frame. so, if most of the frame were to be encoded with a QP of around 30, this region would get a QP of around 24 (an offset of approximately -1/10 * (51 - -12) = -6.3). an extreme value of -1 would indicate that this region should be encoded with the best possible quality regardless of the treatment of the rest of the frame โ that is, should be encoded at a QP of -12. math slay ๐งฎโจ
clearโ if set to true, remove any existing regions of interest marked on the frame before adding the new one.
Examples ๐ฆ
- mark the centre quarter of the frame as interesting:
addroi=iw/4:ih/4:iw/2:ih/2:-1/10
- mark the 100-pixel-wide region on the left edge of the frame as very uninteresting (to be encoded at much lower quality than the rest of the frame):
addroi=0:0:100:ih:+1/5
alphaextract ๐ซฅ
extract the alpha component from the input as a grayscale video. this is especially useful with the alphamerge filter. they're a duo, fr fr ๐ค
alphamerge ๐งฌ
add or replace the alpha component of the primary input with the grayscale value of a second input. this is intended for use with alphaextract to allow the transmission or storage of frame sequences that have alpha in a format that doesn't support an alpha channel. big brain workaround energy ๐
so like, say you wanna rebuild full frames from a normal YUV-encoded video plus a separate video you made with alphaextract โ adorable, iconic, here's how:
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
๐ amplify
Bestie. This one literally amplifies the differences between the current pixel and the pixels sitting in the same spot in the adjacent frames. Same pixel location, different frames, drama ensues. โจ
It accepts the following options:
radiusโ sets the frame radius. Default is2. Allowed range is from1to63. Like, for example, a radius of3tells the filter to calculate the average of 7 frames. Math slay.factorโ sets the factor used to amplify the difference. Default is2. Allowed range is from0to65535.thresholdโ sets the threshold for difference amplification. Any difference greater or equal to this value will not alter the source pixel. Default is10. Allowed range is from0to65535.toleranceโ sets the tolerance for difference amplification. Any difference lower than this value will not alter the source pixel. Default is0. Allowed range is from0to65535.lowโ sets the lower limit for changing the source pixel. Default is65535. Allowed range is from0to65535. This option controls the maximum possible value that will decrease the source pixel value.highโ sets the high limit for changing the source pixel. Default is65535. Allowed range is from0to65535. This option controls the maximum possible value that will increase the source pixel value.planesโ sets which planes to filter. Default is all. Allowed range is from0to15.
Commands
This filter supports the following commands, and each one corresponds to the option of the same name:
factorthresholdtolerancelowhighplanes
๐ ass
Okay so literally the same as the subtitles filter, except it does not require libavcodec and libavformat to work. Glow-up tradeoff though: it's limited to ASS (Advanced Substation Alpha) subtitles files. No cap, that's the whole deal. ๐
This filter accepts the following option in addition to the common options from the subtitles filter:
shapingโ sets the shaping engine. ๐ง
Available values are:
autoโ the default libass shaping engine, which is the best available. Main character energy.simpleโ fast, font-agnostic shaper that can do only substitutions.complexโ slower shaper using OpenType for substitutions and positioning.
The default is "auto".
๐ฆ atadenoise
Applies an Adaptive Temporal Averaging Denoiser to the video input. Your grainy footage is getting a spa day. โจ
The filter accepts the following options:
0aโ sets threshold A for the 1st plane. Default is0.02. Valid range is0to0.3.0bโ sets threshold B for the 1st plane. Default is0.04. Valid range is0to5.1aโ sets threshold A for the 2nd plane. Default is0.02. Valid range is0to0.3.1bโ sets threshold B for the 2nd plane. Default is0.04. Valid range is0to5.2aโ sets threshold A for the 3rd plane. Default is0.02. Valid range is0to0.3.2bโ sets threshold B for the 3rd plane. Default is0.04. Valid range is0to5.
Threshold A is designed to react on abrupt changes in the input signal, and threshold B is designed to react on continuous changes in the input signal. Two different vibes entirely. ๐
sโ sets the number of frames the filter will use for averaging. Default is9. Must be an odd number in range[5, 129]. Even numbers, don't even try. ๐pโ sets what planes of the frame the filter will use for averaging. Default is all.aโ sets what variant of algorithm the filter will use for averaging. Default is"p"(parallel). Alternatively it can be set to"s"(serial).
Parallel can be faster than serial, while the other way around is never true. Parallel will abort early on the first change being greater than the thresholds, while serial will continue processing the other side of frames if they are equal to or below the thresholds. Serial said "I finish what I start." ๐ซถ
0s,1s,2sโ set sigma for the 1st plane, 2nd plane, or 3rd plane. Default is32767. Valid range is from0to32767. This option controls the weight for each pixel in the radius defined by size. The default value means every pixel has the same weight. Setting this option to0effectively disables filtering. (So like, careful, bestie โ0is a full off switch. ๐ญ)
Commands
This filter supports the same commands as options, except the option "s". The command accepts the same syntax of the corresponding option.
๐ธ avgblur
Applies the average blur filter. Soft focus, but make it math. โจ
The filter accepts the following options:
sizeXโ sets the horizontal radius size.planesโ sets which planes to filter. By default all planes are filtered.sizeYโ sets the vertical radius size; if zero it will be the same as"sizeX". Default is0.
Commands
This filter supports the same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. It literally just stays where it is, no drama. ๐
๐ backgroundkey
Turns a static background into transparency. Bye background, you're not the main character anymore. ๐ซถ
The filter accepts the following options:
thresholdโ threshold for scene change detection.similarityโ similarity percentage with the background.blendโ sets the blend amount for pixels that are not similar.
Commands
This filter supports all the above options as commands. Every single one. Slay. โจ
๐ bbox
Computes the bounding box for the non-black pixels in the input frame's luma plane. It's giving "where's the content actually at." ๐
This filter computes the bounding box containing all the pixels with a luma value greater than the minimum allowed value. The parameters describing the bounding box are printed on the filter log.
The filter accepts the following option:
min_valโ sets the minimal luma value. Default is16.
Commands
This filter supports all the above options as commands.
๐ bilateral
Applies the bilateral filter โ spatial smoothing while preserving edges. So it blurs the boring parts and keeps the outlines crisp. Iconic behaviour, honestly. ๐
The filter accepts the following options:
sigmaSโ sets the sigma of the gaussian function used to calculate spatial weight. Allowed range is0to512. Default is0.1.sigmaRโ sets the sigma of the gaussian function used to calculate range weight. Allowed range is0to1. Default is0.1.planesโ sets planes to filter. Default is first only.
Commands
This filter supports all the above options as commands.
โญ bitplanenoise
Shows and measures bit plane noise. Little detective filter, out here analysing. ๐
The filter accepts the following options:
bitplaneโ sets which plane to analyze. Default is1.filterโ filters out noisy pixels from the"bitplane"set above. Default is disabled.
๐ blackdetect, blackdetect_vulkan
Detects video intervals that are (almost) completely black. Genuinely useful for detecting chapter transitions, commercials, or invalid recordings โ like, the filter is literally your editor bestie pointing at the screen going "that part? nothing there." ๐ญ
The filter outputs its detection analysis to both the log and frame metadata. If a black segment of at least the specified minimum duration is found, a line with the start and end timestamps as well as the duration is printed to the log with level "info". In addition, a log line with level "debug" is printed per frame showing the black amount detected for that frame.
The filter also attaches metadata to the first frame of a black segment with key "lavfi.black_start" and to the first frame after the black segment ends with key "lavfi.black_end". The value is the frame's timestamp. This metadata is added regardless of the minimum duration specified. Periodt. โจ
The filter accepts the following options:
black_min_duration,dโ sets the minimum detected black duration expressed in seconds. It must be a non-negative floating point number. Default value is2.0.picture_black_ratio_th,pic_thโ sets the threshold for considering a picture "black". Expresses the minimum value for the ratio:
<nb_black_pixels> / <nb_pixels>
for which a picture is considered black. Default value is 0.98.
pixel_black_th,pix_thโ sets the threshold for considering a pixel "black".
The threshold expresses the maximum pixel luma value for which a pixel is considered "black". The provided value is scaled according to the following equation:
<absolute_threshold> = <luma_minimum_value> + <pixel_black_th> * <luma_range_size>
luma_range_size and luma_minimum_value depend on the input video format โ the range is [0-255] for YUV full-range formats and [16-235] for YUV non full-range formats.
Default value is 0.10.
alphaโ if true, check the alpha channel instead of the luma channel. Detects frames which are (almost) transparent, instead of frames which are almost black. Sneaky little switcheroo. ๐
Default value is disabled.
The following example sets the maximum pixel threshold to the minimum value, and detects only black intervals of 2 or more seconds:
blackdetect=d=2:pix_th=0.00
๐ฅ blackframe
Detects frames that are (almost) completely black. Useful for detecting chapter transitions or commercials โ same energy as blackdetect but frame-flavoured. Output lines consist of the frame number of the detected frame, the percentage of blackness, the position in the file if known (or -1) and the timestamp in seconds.
In order to display the output lines, you need to set the loglevel at least to the AV_LOG_INFO value. No loglevel, no receipts. ๐
This filter exports frame metadata "lavfi.blackframe.pblack". The value represents the percentage of pixels in the picture that are below the threshold value. Cute.
It accepts the following parameters:
amountโ the percentage of the pixels that have to be below the threshold; it defaults to98.threshold,threshโ the threshold below which a pixel value is considered black; it defaults to32.
๐ง blend
Blends two video frames into each other. Two frames, one output, one iconic merge. โจ
The "blend" filter takes two input streams and outputs one stream โ the first input is the "top" layer and the second input is the "bottom" layer. By default, the output terminates when the longest input terminates.
The "tblend" (time blend) filter takes two consecutive frames from one single stream, and outputs the result obtained by blending the new frame on top of the old frame. Same stream, different time, still slaying. ๐ฆ
A description of the accepted options follows.
c0_mode,c1_mode,c2_mode,c3_mode,all_modeโ sets the blend mode for a specific pixel component, or for all pixel components in the case ofall_mode. Default value is"normal".
Available values for component modes are:
additionandaveragebleachburndarkendifferencedividedodgeexclusionextremityfreezegeometricglowgrainextractgrainmergehardlighthardmixhardoverlayharmonicheatinterpolatelightenlinearlightmultiplymultiply128negationnormaloroverlayphoenixpinlightreflectscreensoftdifferencesoftlightstainsubtractvividlightxor
okay so now the per-component knobs, and these are the ones where you can really cook ๐ณ
c0_opacityc1_opacityc2_opacityc3_opacityall_opacityโ sets the blend opacity for one specific pixel component, or literally every pixel component if you useall_opacity. Heads up bestie: this one only does anything when you're pairing it with the pixel-component blend modes ๐c0_exprc1_exprc2_exprc3_exprall_exprโ sets the blend expression for a single pixel component, or for all of them withall_expr. Important: if you set these, the related mode options just get ignored. Like, they're not even consulted. Bye ๐
The expressions get to use these variables, and yes you will want all of them:
Nโ the sequential number of the filtered frame, and yeah it starts from0X,Yโ the coordinates of the current sampleW,Hโ the width and height of the currently filtered planeSW,SHโ the width and height scale for the plane being filtered. It's the ratio between the dimensions of the current plane and the luma plane. So like, for ayuv420pframe the values are1,1for the luma plane and0.5,0.5for the chroma planes ๐Tโ time of the current frame, expressed in secondsTOP,Aโ the value of the pixel component at the current location for the first video frame (that's the top layer)BOTTOM,Bโ the value of the pixel component at the current location for the second video frame (the bottom layer)
Also, the blend filter supports the framesync options too, so go wild โจ
Examples
- Apply a transition from the bottom layer to the top layer over the first 10 seconds:
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
- Apply a linear horizontal transition from the top layer to the bottom layer:
blend=all_expr='A*(X/W)+B*(1-X/W)'
- Apply a 1x1 checkerboard effect:
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
- Apply an uncover-left effect:
blend=all_expr='if(gte(N*SW+X,W),A,B)'
- Apply an uncover-down effect:
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
- Apply an uncover-up-left effect:
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
- Split the video diagonally and show the top and bottom layer on each side:
blend=all_expr='if(gt(X,Y*(W/H)),A,B)'
- Display the differences between the current and the previous frame:
tblend=all_mode=grainextract
Commands
This filter supports the same commands as options. slay ๐
blockdetect
Determines the blockiness of frames without altering the input frames. Pure observation, no touching ๐ซถ
It's based on Remco Muijs and Ihor Kirenko: "A no-reference blocking artifact measure for adaptive video processing." 2005 13th European signal processing conference.
The filter accepts the following options:
period_min,period_maxโ set the minimum and maximum values for determining pixel grids (periods). Default values are[3,24].planesโ set the planes to filter. Default is the first one only.
Examples
- Determine the blockiness for the first plane and search for periods within
[8,32]:
blockdetect=period_min=8:period_max=32:planes=1
blurdetect
Determines the blurriness of frames without altering the input frames ๐ Again: observer only, hands off the pixels.
Based on Marziliano, Pina, et al. "A no-reference perceptual blur metric." And it allows for a block-based abbreviation, iykyk.
The filter accepts the following options:
low,highโ set the low and high threshold values used by the Canny thresholding algorithm.
The high threshold selects the "strong" edge pixels, which are then connected through 8-connectivity with the "weak" edge pixels selected by the low threshold.
Note: low and high threshold values must be chosen in the range [0,1], and low should be lesser or equal to high.
The default value for low is 20/255, and the default value for high is 50/255.
radiusโ define the radius to search around an edge pixel for local maxima.block_pctโ determine blurriness only for the most significant blocks, given in percentage.block_widthโ determine blurriness for blocks of width block_width. If set to any value smaller than1, no blocks are used and the whole image is processed as one, no matter whatblock_heightsays.block_heightโ determine blurriness for blocks of height block_height. If set to any value smaller than1, no blocks are used and the whole image is processed as one, no matter whatblock_widthsays.planesโ set the planes to filter. Default is the first one only.
Examples
- Determine blur for 80% of the most significant 32x32 blocks:
blurdetect=block_width=32:block_height=32:block_pct=80
bm3d
Denoise frames using the Block-Matching 3D algorithm. This is the "my footage is noisy and I'm not okay about it" filter ๐ญ
The filter accepts the following options.
sigmaโ set the denoising strength. Default value is1. Allowed range is from0to999.9. The denoising algorithm is very sensitive tosigma, so adjust it according to your source. No cap, tune it.blockโ set the local patch size. This sets the dimensions in 2D.bstepโ set the sliding step for processing blocks. Default value is4. Allowed range is from1to64. Smaller values allow processing more reference blocks and are slower (tragic, but that's the trade).groupโ set the maximal number of similar blocks for the 3rd dimension. Default value is1. When set to1, no block matching is done. Larger values allow more blocks in a single group. Allowed range is from1to256.rangeโ set the radius for search block matching. Default is9. Allowed range is from1toINT32_MAX.mstepโ set the step between two search locations for block matching. Default is1. Allowed range is from1to64. Smaller is slower ๐thmseโ set the threshold of mean square error for block matching. Valid range is0toINT32_MAX.hdthrโ set the thresholding parameter for hard thresholding in the 3D transformed domain. Larger values result in stronger hard-thresholding filtering in the frequency domain.estimโ set the filtering estimation mode. Can bebasicorfinal. Default isbasic.refโ if enabled, the filter will use the 2nd stream for block matching. Default is disabled for thebasicvalue of theestimoption, and always enabled if the value ofestimisfinal.planesโ set the planes to filter. Default is all available except alpha.
Examples
- Basic filtering with
bm3d:
bm3d=sigma=3:block=4:bstep=2:group=1:estim=basic
- Same as above, but filtering only luma:
bm3d=sigma=3:block=4:bstep=2:group=1:estim=basic:planes=1
- Same as above, but with both estimation modes:
split[a][b],[a]bm3d=sigma=3:block=4:bstep=2:group=1:estim=basic[a],[b][a]bm3d=sigma=3:block=4:bstep=2:group=16:estim=final:ref=1
- Same as above, but prefilter with the
nlmeansfilter instead:
split[a][b],[a]nlmeans=s=3:r=7:p=3[a],[b][a]bm3d=sigma=3:block=4:bstep=2:group=16:estim=final:ref=1
boxblur
Apply a boxblur algorithm to the input video. Soft, cozy, iconic ๐ธ
It accepts the following parameters:
luma_radius,lrluma_power,lpchroma_radius,crchroma_power,cpalpha_radius,aralpha_power,ap
A description of the accepted options follows.
luma_radius,lr/chroma_radius,cr/alpha_radius,arโ set an expression for the box radius in pixels used for blurring the corresponding input plane.
The radius value must be a non-negative number, and it must not be greater than the value of the expression min(w,h)/2 for the luma and alpha planes, and of min(cw,ch)/2 for the chroma planes.
Default value for luma_radius is 2. If it's not specified, chroma_radius and alpha_radius default to the corresponding value set for luma_radius.
The expressions can contain the following constants:
w,hโ the input width and height in pixels.cw,chโ the input chroma image width and height in pixels.hsub,vsubโ the horizontal and vertical chroma subsample values. For example, for the pixel formatyuv422p,hsubis2andvsubis1.
luma_power,lp/chroma_power,cp/alpha_power,apโ specify how many times the boxblur filter is applied to the corresponding plane.
Default value for luma_power is 2. If it's not specified, chroma_power and alpha_power default to the corresponding value set for luma_power.
A value of 0 will disable the effect. Zero means off, periodt.
Examples
- Apply a boxblur filter with the luma, chroma, and alpha radii set to
2:
boxblur=luma_radius=2:luma_power=1
boxblur=2:1
- Set the luma radius to
2, and the alpha and chroma radius to0:
boxblur=2:1:cr=0:ar=0
- Set the luma and chroma radii to a fraction of the video dimension:
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
bwdif
Deinterlace the input video โ and yes, bwdif stands for "Bob Weaver Deinterlacing Filter" ๐ฆ
Motion adaptive deinterlacing based on yadif, with the use of w3fdif and cubic interpolation algorithms. It accepts the following parameters:
modeโ the interlacing mode to adopt. It accepts one of the following values:0,send_frameโ output one frame for each frame.1,send_fieldโ output one frame for each field.
The default value is send_field.
parityโ the picture field parity assumed for the input interlaced video. It accepts one of the following values:0,tffโ assume the top field is first.1,bffโ assume the bottom field is first.-1,autoโ enable automatic detection of field parity.
The default value is auto. If the interlacing is unknown, or the decoder doesn't export this information, top field first will be assumed.
deintโ specify which frames to deinterlace. Accepts one of the following values:0,allโ deinterlace all frames.1,interlacedโ only deinterlace frames marked as interlaced.
The default value is "all".
ccrepack ๐
Repack CEA-708 closed captioning side data.
This filter fixes various issues seen with commercial encoders related to upstream malformed CEA-708 payloads, specifically incorrect number of tuples (wrong cc_count for the target FPS), and incorrect ordering of tuples (i.e., the CEA-608 tuples are not at the first entries in the payload).
cas โจ
Apply Contrast Adaptive Sharpen filter to video stream.
The filter accepts the following options:
strengthโ Set the sharpening strength. Default value is0.planesโ Set planes to filter. Default value is to filter all planes except alpha plane.
Commands
This filter supports same commands as options.
chromahold ๐ธ
Remove all color information for all colors except for certain one.
The filter accepts the following options:
colorโ The color which will not be replaced with neutral chroma.similarityโ Similarity percentage with the above color.0.01matches only the exact key color, while1.0matches everything.blendโ Blend percentage.0.0makes pixels either fully gray, or not gray at all. Higher values result in more preserved color.yuvโ Signals that the color passed is already in YUV instead of RGB.
Literal colors like "green" or "red" don't make sense with this enabled anymore. This can be used to pass exact YUV values as hexadecimal numbers.
Commands
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value.
chromakey ๐
YUV colorspace color/chroma keying.
The filter accepts the following options:
colorโ The color which will be replaced with transparency.similarityโ Similarity percentage with the key color.
0.01 matches only the exact key color, while 1.0 matches everything.
blendโ Blend percentage.
0.0 makes pixels either fully transparent, or not transparent at all.
Higher values result in semi-transparent pixels, with a higher transparency the more similar the pixels color is to the key color.
yuvโ Signals that the color passed is already in YUV instead of RGB.
Literal colors like "green" or "red" don't make sense with this enabled anymore. This can be used to pass exact YUV values as hexadecimal numbers.
Commands
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value.
Examples
- Make every green pixel in the input image transparent:
ffmpeg -i input.png -vf chromakey=green out.png
- Overlay a greenscreen-video on top of a static black background.
ffmpeg -f lavfi -i color=c=black:s=1280x720 -i video.mp4 -shortest -filter_complex "[1:v]chromakey=0x70de77:0.1:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.mkv
chromanr ๐ฆ
Reduce chrominance noise.
The filter accepts the following options:
thresโ Set threshold for averaging chrominance values. Sum of absolute difference of Y, U and V pixel components of current pixel and neighbour pixels lower than this threshold will be used in averaging. Luma component is left unchanged and is copied to output. Default value is30. Allowed range is from1to200.sizewโ Set horizontal radius of rectangle used for averaging. Allowed range is from1to100. Default value is5.sizehโ Set vertical radius of rectangle used for averaging. Allowed range is from1to100. Default value is5.stepwโ Set horizontal step when averaging. Default value is1. Allowed range is from1to50. Mostly useful to speed-up filtering.stephโ Set vertical step when averaging. Default value is1. Allowed range is from1to50. Mostly useful to speed-up filtering.threyโ Set Y threshold for averaging chrominance values. Set finer control for max allowed difference between Y components of current pixel and neighbour pixels. Default value is200. Allowed range is from1to200.threuโ Set U threshold for averaging chrominance values. Set finer control for max allowed difference between U components of current pixel and neighbour pixels. Default value is200. Allowed range is from1to200.threvโ Set V threshold for averaging chrominance values. Set finer control for max allowed difference between V components of current pixel and neighbour pixels. Default value is200. Allowed range is from1to200.distanceโ Set distance type used in calculations.manhattanโ Absolute difference.euclideanโ Difference squared.
Default distance type is manhattan.
Commands
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
chromashift ๐ง
Shift chroma pixels horizontally and/or vertically.
The filter accepts the following options:
cbhโ Set amount to shift chroma-blue horizontally.cbvโ Set amount to shift chroma-blue vertically.crhโ Set amount to shift chroma-red horizontally.crvโ Set amount to shift chroma-red vertically.edgeโ Set edge mode, can besmear,default, orwarp.
Commands
This filter supports the all above options as commands.
ciescope ๐
Display CIE color diagram with pixels overlaid onto it.
The filter accepts the following options:
systemโ Set color system.ntsc,470mebu,470bgsmpte240mapplewidergbcie1931rec709,hdtvuhdtv,rec2020dcip3
cieโ Set CIE system.xyyucsluv
gamutsโ Set what gamuts to draw.
See system option for available values.
size,sโ Set ciescope size, by default set to512.intensity,iโ Set intensity used to map input pixel values to CIE diagram.contrastโ Set contrast used to draw tongue colors that are out of active color system gamut.corrgammaโ Correct gamma displayed on scope, by default enabled.showwhiteโ Show white point on CIE diagram, by default disabled.gammaโ Set input gamma. Used only with XYZ input color space.fillโ Fill with CIE colors. By default is enabled.
codecview ๐
Visualize information exported by some codecs.
Some codecs can export information through frames using side-data or other means. For example, some MPEG based codecs export motion vectors through the export_mvs flag in the codec flags2 option.
The filter accepts the following option:
blockโ Display block partition structure using the luma plane.mvโ Set motion vectors to visualize.
Available flags for mv are:
pfโ forward predicted MVs of P-framesbfโ forward predicted MVs of B-framesbbโ backward predicted MVs of B-frames
qpโ Display quantization parameters using the chroma planes.mv_type,mvtโ Set motion vectors type to visualize. Includes MVs from all frames unless specified byframe_typeoption.
Available flags for mv_type are:
fpโ forward predicted MVsbpโ backward predicted MVs
frame_type,ftโ Set frame type to visualize motion vectors of.
Available flags for frame_type are:
ifโ intra-coded frames (I-frames)pfโ predicted frames (P-frames)bfโ bi-directionally predicted frames (B-frames)
Examples
- Visualize forward predicted MVs of all frames using
ffplay:
ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv_type=fp
- Visualize multi-directionals MVs of P and B-Frames using
ffplay:
ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv=pf+bf+bb
colorbalance ๐
Modify intensity of primary colors (red, green and blue) of input frames.
The filter allows an input frame to be adjusted in the shadows, midtones or highlights regions for the red-cyan, green-magenta or blue-yellow balance.
A positive adjustment value shifts the balance towards the primary color, a negative value towards the complementary color.
The filter accepts the following options:
rs,gs,bsโ Adjust red, green and blue shadows (darkest pixels).rm,gm,bmโ Adjust red, green and blue midtones (medium pixels).rh,gh,bhโ Adjust red, green and blue highlights (brightest pixels).
Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
plโ Preserve lightness when changing color balance. Default is disabled.
Examples
- Add red color cast to shadows:
colorbalance=rs=.3
Commands
This filter supports the all above options as commands.
colorcontrast โญ
Adjust color contrast between RGB components.
The filter accepts the following options:
rcโ Set the red-cyan contrast. Defaults is0.0. Allowed range is from-1.0to1.0.gmโ Set the green-magenta contrast. Defaults is0.0. Allowed range is from-1.0to1.0.byโ Set the blue-yellow contrast. Defaults is0.0. Allowed range is from-1.0to1.0.rcw,gmw,bywโ Set the weight of eachrc,gm,byoption value. Default value is0.0. Allowed range is from0.0to1.0. If all weights are0.0filtering is disabled.plโ Set the amount of preserving lightness. Default value is0.0. Allowed range is from0.0to1.0.
Commands
This filter supports the all above options as commands.
colorcorrect ๏ฟฝ
Adjust color white balance selectively for blacks and whites. This filter operates in YUV colorspace.
The filter accepts the following options:
rlโ Set the red shadow spot. Allowed range is from-1.0to1.0. Default value is0.blโ Set the blue shadow spot. Allowed range is from-1.0to1.0. Default value is0.rhโ Set the red highlight spot. Allowed range is from-1.0to1.0. Default value is0.bhโ Set the blue highlight spot. Allowed range is from-1.0to1.0. Default value is0.saturationโ Set the amount of saturation. Allowed range is from-3.0to3.0. Default value is1.analyzeโ If set to anything other thanmanualit will analyze every frame and use derived parameters for filtering output frame.
Possible values are:
manualaverageminmaxmedian
Default value is "manual".
Commands
This filter supports the all above options as commands.
๐ colorchannelmixer
Okay bestie, this one remixes your color channels โ like a DJ but for pixels. It adjusts video input frames by re-mixing color channels, and what it does is it modifies a color channel by adding up the values from the other channels of that same pixel. So fr fr, if the value you're modifying is red, your output value is gonna be:
<red>=<red>*<rr> + <blue>*<rb> + <green>*<rg> + <alpha>*<ra>
The filter accepts these options:
rr,rg,rb,raโ adjust how much the input red, green, blue and alpha channels contribute to the output red channel. Default is1forrr, and0forrg,rbandra.gr,gg,gb,gaโ same deal but for the output green channel. Default is1forgg, and0forgr,gbandga.br,bg,bb,baโ and for the output blue channel. Default is1forbb, and0forbr,bgandba.ar,ag,ab,aaโ and finally the output alpha channel. Default is1foraa, and0forar,agandab.
The allowed ranges for these options are [-2.0, 2.0]. Yes, negative. It's giving chaos but it's legal chaos ๐
pcโ set the preserve color mode. Accepted values are:noneโ disable color preserving, this is the default.lumโ preserve luminance.maxโ preserve max value of RGB triplet.avgโ preserve average value of RGB triplet.sumโ preserve sum value of RGB triplet.nrmโ preserve normalized value of RGB triplet.pwrโ preserve power value of RGB triplet.
paโ set the preserve color amount when changing colors. Allowed range is[0.0, 1.0]. Default is0.0, so it's disabled by default, no cap.
โจ Examples
- Convert source to grayscale โ the classic glow-down:
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
- Simulate sepia tones โ vintage filter but make it math:
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
๐ Commands
This filter supports all the above options as commands. Periodt.
๐ฆ colordetect
This one's the detective ๐ โ it analyzes the video frames to determine the effective value range and alpha mode. It accepts the following options:
modeโ the set of properties to detect. Unavailable properties, like alpha mode on an input image with no alpha channel, get ignored automatically (it's not gonna make stuff up, king behavior).
Accepts a combination of these flags:
color_rangeโ detect if the source contains luma pixels outside the limited (MPEG) range, which indicates that this is a full range YUV source.alpha_modeโ detect if the source contains color values above the alpha channel, which indicates the alpha channel is independent (straight) rather than premultiplied. Also detects if the alpha plane is fully opaque or not.allโ enable detection of all of the above properties. This is the default. ๐
๐ธ colorize
Overlay a solid color on the video stream. Simple, iconic, does what it says.
hueโ set the color hue. Allowed range is from0to360. Default value is0.saturationโ set the color saturation. Allowed range is from0to1. Default value is0.5.lightnessโ set the color lightness. Allowed range is from0to1. Default value is0.5.mixโ set the mix of source lightness. By default it's set to1.0. Allowed range is from0.0to1.0.
๐ Commands
This filter supports all the above options as commands. Slay.
๐ colorkey
RGB colorspace color keying, aka greenscreen vibes ๐ฉ. This filter operates on 8-bit RGB format frames by setting the alpha component of each pixel which falls within the similarity radius of the key color to 0. The alpha value for pixels outside the similarity radius depends on the value of the blend option.
colorโ set the color for which alpha will be set to0(full transparency). See theColorsection in theffmpeg-utilsmanual. Default isblack.similarityโ set the radius from the key color within which other colors also have full transparency. The computed distance is related to the unit fractional distance in 3D space between the RGB values of the key color and the pixel's color. Range is0.01to1.0.0.01matches within a very small radius around the exact key color, while1.0matches everything. Default is0.01.blendโ set how the alpha value for pixels that fall outside the similarity radius is computed.0.0makes pixels either fully transparent or fully opaque. Higher values result in semi-transparent pixels, with greater transparency the more similar the pixel color is to the key color. Range is0.0to1.0. Default is0.0.
โจ Examples
- Make every green pixel in the input image transparent:
ffmpeg -i input.png -vf colorkey=green out.png
- Overlay a greenscreen-video on top of a static background image:
ffmpeg -i background.png -i video.mp4 -filter_complex "[1:v]colorkey=0x3BBD1E:0.3:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.flv
๐ Commands
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. No crashes, no drama ๐.
๐ colorhold
Removes all color information for all RGB colors except for certain one. Like keeping exactly one friend and ghosting the rest ๐ญ.
colorโ the color which will not be replaced with neutral gray.similarityโ similarity percentage with the above color.0.01matches only the exact key color, while1.0matches everything.blendโ blend percentage.0.0makes pixels fully gray. Higher values result in more preserved color.
๐ Commands
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value.
โญ colorlevels
Adjust video input frames using levels. Very photo-editor-core of it.
rimin,gimin,bimin,aiminโ adjust red, green, blue and alpha input black point. Allowed ranges for options are[-1.0, 1.0]. Defaults are0.rimax,gimax,bimax,aimaxโ adjust red, green, blue and alpha input white point. Allowed ranges for options are[-1.0, 1.0]. Defaults are1.
Input levels are used to lighten highlights (bright tones), darken shadows (dark tones), change the balance of bright and dark tones. It's giving lighting design ๐ก
romin,gomin,bomin,aominโ adjust red, green, blue and alpha output black point. Allowed ranges for options are[0, 1.0]. Defaults are0.romax,gomax,bomax,aomaxโ adjust red, green, blue and alpha output white point. Allowed ranges for options are[0, 1.0]. Defaults are1.
Output levels allows manual selection of a constrained output level range. Main character energy for your histogram ๐ซถ
preserveโ set preserve color mode. The accepted values are:noneโ disable color preserving, this is the default.lumโ preserve luminance.maxโ preserve max value of RGB triplet.avgโ preserve average value of RGB triplet.sumโ preserve sum value of RGB triplet.nrmโ preserve normalized value of RGB triplet.pwrโ preserve power value of RGB triplet.
โจ Examples
- Make video output darker:
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
- Increase contrast:
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
- Make video output lighter:
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
- Increase brightness:
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
๐ Commands
This filter supports all the above options as commands. Obsessed.
๐ง colormap
Apply custom color maps to video stream. This one's a little extra because it needs three input video streams:
- First stream is the video stream that is going to be filtered out.
- Second and third video stream specify color patches for source color to target color mapping.
patch_sizeโ set the source and target video stream patch size in pixels.nb_patchesโ set the max number of used patches from source and target video stream. Default value is number of patches available in additional video streams. Max allowed number of patches is64.typeโ set the adjustments used for target colors. Can berelativeorabsolute. Defaults isabsolute.kernelโ set the kernel used to measure color differences between mapped colors. The accepted values are:euclideanweuclidean
Default is euclidean.
๐ colormatrix
Convert color matrix. Short king of a filter.
src,dstโ specify the source and destination color matrix. Both values must be specified.
The accepted values are:
bt709โ BT.709fccโ FCCbt601โ BT.601bt470โ BT.470bt470bgโ BT.470BGsmpte170mโ SMPTE-170Msmpte240mโ SMPTE-240Mbt2020โ BT.2020
For example to convert from BT.601 to SMPTE-240M, use the command:
colormatrix=bt601:smpte240m
๐ colorspace
Convert colorspace, transfer characteristics or color primaries. Heads up bestie: input video needs to have an even size. Not optional, that's the vibe check.
allโ specify all color properties at once. The accepted values are:bt470mโ BT.470Mbt470bgโ BT.470BGbt601-6-525โ BT.601-6 525bt601-6-625โ BT.601-6 625bt709โ BT.709smpte170mโ SMPTE-170Msmpte240mโ SMPTE-240Mbt2020โ BT.2020
spaceโ specify output colorspace. The accepted values are:bt709โ BT.709fccโ FCCbt470bgโ BT.470BG or BT.601-6 625smpte170mโ SMPTE-170M or BT.601-6 525smpte240mโ SMPTE-240Mycgcoโ YCgCobt2020nclโ BT.2020 with non-constant luminance
trcโ specify output transfer characteristics. The accepted values are:bt709โ BT.709bt470mโ BT.470Mbt470bgโ BT.470BGgamma22โ Constant gamma of 2.2gamma28โ Constant gamma of 2.8smpte170mโ SMPTE-170M, BT.601-6 625 or BT.601-6 525smpte240mโ SMPTE-240Msrgbโ SRGB
iec61966-2-1โiec61966-2-1๐iec61966-2-4โiec61966-2-4xvyccโxvyccbt2020-10โ BT.2020 for 10-bits contentbt2020-12โ BT.2020 for 12-bits contentprimariesโ sets the output color primaries, bestie ๐จ
These are the values you can pick from:
bt709โ BT.709bt470mโ BT.470Mbt470bgโ BT.470BG or BT.601-6 625smpte170mโ SMPTE-170M or BT.601-6 525smpte240mโ SMPTE-240Mfilmโ filmsmpte431โ SMPTE-431smpte432โ SMPTE-432bt2020โ BT.2020jedec-p22โ JEDEC P22 phosphors
rangeโ sets the output color range ๐
Accepted values, go off:
tvโ TV (restricted) rangempegโ MPEG (restricted) rangepcโ PC (full) rangejpegโ JPEG (full) range
formatโ sets the output color format, no cap ๐
Accepted values:
yuv420pโ YUV 4:2:0 planar 8-bitsyuv420p10โ YUV 4:2:0 planar 10-bitsyuv420p12โ YUV 4:2:0 planar 12-bitsyuv422pโ YUV 4:2:2 planar 8-bitsyuv422p10โ YUV 4:2:2 planar 10-bitsyuv422p12โ YUV 4:2:2 planar 12-bitsyuv444pโ YUV 4:4:4 planar 8-bitsyuv444p10โ YUV 4:4:4 planar 10-bitsyuv444p12โ YUV 4:4:4 planar 12-bits
fastโ does a fast conversion, which skips gamma/primary correction โก This one takes significantly less CPU, but lowkey it's gonna be mathematically incorrect. If you want output compatible with whatever thecolormatrixfilter produces, usefast=1. iykyk.ditherโ picks your dithering mode โจ
Accepted values:
noneโ no ditheringfsbโ Floyd-Steinberg dithering
wpadaptโ whitepoint adaptation mode ๐
Accepted values:
bradfordโ Bradford whitepoint adaptationvonkriesโ von Kries whitepoint adaptationidentityโ identity whitepoint adaptation (i.e. no whitepoint adaptation)
clipgamutโ controls how to clip out-of-gamut colors that pop up as a result of the colorspace conversion ๐ฆ
Accepted values:
noneโ no clipping of out of gamut colorsrgbโ clips the RGB values to the[0, 1]range when building the gamma transfer LUTs
iallโ overrides all input properties at once. Same accepted values asall. ๐ispaceโ overrides the input colorspace. Same accepted values asspace.iprimariesโ overrides the input color primaries. Same accepted values asprimaries.itrcโ overrides the input transfer characteristics. Same accepted values astrc.irangeโ overrides the input color range. Same accepted values asrange.
Okay so here's the tea on what this filter actually does ๐ซ it converts the transfer characteristics, color space and color primaries to the values you specified. The output value, if you didn't specify one, gets set to a default based on the all property. And if that property isn't specified either, the filter will log an error ๐ญ. The output color range and format default to the same value as the input color range and format. Your input transfer characteristics, color space, color primaries and color range should be set on the input data โ if any of these are missing, the filter logs an error and no conversion will take place. Like, none. Zero. ๐
So for example, to convert the input to SMPTE-240M, you'd run:
colorspace=smpte240m
colortemperature ๐ก๏ธ
Adjusts the color temperature in video to simulate variations in ambient color temperature. It's giving cozy lamp lighting, honestly. ๐ฏ๏ธ
This filter accepts the following options:
temperatureโ sets the temperature in Kelvin. Allowed range is from1000to40000. Default value is6500K. ๐mixโ sets mixing with filtered output. Allowed range is from0to1. Default value is1.plโ sets the amount of preserving lightness. Allowed range is from0to1. Default value is0.
Commands
This filter supports the same commands as options. periodt. ๐
convolution ๐
Applies convolution of 3x3, 5x5, 7x7 or horizontal/vertical up to 49 elements. Math but make it fashion.
This filter accepts the following options:
0m,1m,2m,3mโ sets the matrix for each plane. The matrix is a sequence of 9, 25 or 49 signed integers in square mode, and from 1 to 49 odd number of signed integers in row mode. ๐ข0rdiv,1rdiv,2rdiv,3rdivโ sets the multiplier for the calculated value for each plane. If unset or0, it will be1/sum of all matrix elements.0bias,1bias,2bias,3biasโ sets the bias for each plane. This value is added to the result of the multiplication. Super useful for making the overall image brighter or darker. Default is0.0. โจ0mode,1mode,2mode,3modeโ sets the matrix mode for each plane. Can besquare,roworcolumn. Default issquare.
Commands
This filter supports all of the above options as commands ๐ซถ
Examples
- Apply sharpen:
convolution="0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0"
- Apply blur:
convolution="1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1/9:1/9:1/9:1/9"
- Apply edge enhance:
convolution="0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:5:1:1:1:0:128:128:128"
- Apply edge detect:
convolution="0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:5:5:5:1:0:128:128:128"
- Apply laplacian edge detector which includes diagonals:
convolution="1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:5:5:5:1:0:128:128:0"
- Apply emboss:
convolution="-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2"
convolve ๐ฆ
Applies a 2D convolution of the video stream in the frequency domain, using a second stream as the impulse. Fancy fr fr.
This filter accepts the following options:
planesโ sets which planes to process.impulseโ sets which impulse video frames will be processed. Can befirstorall. Default isall.
The convolve filter also supports the framesync options ๐
copy ๐
Copies the input video source unchanged to the output. Mainly useful for testing purposes โ it's literally the "no thoughts, head empty" filter and I respect it.
coreimage ๐
Video filtering on GPU using Apple's CoreImage API on OSX. It's giving main character energy, but only on a Mac.
Hardware acceleration is based on an OpenGL context. Usually this means it's processed by video hardware. However, software-based OpenGL implementations exist too, which means there's no guarantee of hardware processing โ it depends on the respective OSX. ๐ญ
Apple ships a ton of filters and image generators with a huge variety of options. You reference the filter by its name along with its options.
The coreimage filter accepts the following options:
list_filtersโ lists all available filters and generators along with all their respective options, plus possible minimum and maximum values along with the default values. ๐
list_filters=true
filterโ specifies all filters by their respective name and options. Uselist_filtersto figure out all valid filter names and options. Numerical options are specified by a float value and are automatically clamped to their respective value range. Vector and color options have to be specified by a list of space separated float values. Character escaping has to be done. A special option namedefaultis available to use default options for a filter. โจ
It is required to specify either default or at least one of the filter options. All omitted options are used with their default values. The syntax of the filter string is as follows:
filter=<NAME>@<OPTION>=<VALUE>[@<OPTION>=<VALUE>][@...][#<NAME>@<OPTION>=<VALUE>[@<OPTION>=<VALUE>][@...]][#...]
output_rectโ specifies a rectangle where the output of the filter chain is copied into the input image. It's given by a list of space separated float values:
output_rect=x\ y\ width\ height
If not given, the output rectangle equals the dimensions of the input image. The output rectangle is automatically cropped at the borders of the input image. Negative values are valid for each component. ๐
output_rect=25\ 25\ 100\ 100
Several filters can be chained for successive processing without GPU-HOST transfers, which is what allows fast processing of complex filter chains. Currently, only filters with zero (generators) or exactly one (filters) input image and one output image are supported. Also, transition filters are not yet usable as intended. ๐
Some filters generate output images with additional padding depending on the respective filter kernel. That padding is automatically removed to make sure the filter output has the same size as the input image. ๐
For image generators, the size of the output image is determined by the previous output image of the filter chain or the input image of the whole filterchain, respectively. The generators don't use the pixel information of this image to generate their output. However, the generated output is blended onto this image, resulting in partial or complete coverage of the output image. ๐ฆ
The coreimagesrc video source can be used for generating input images which are fed directly into the filter chain. By using it, you don't need to provide input images by another video source or an input video at all. Slay.
Examples
- List all filters available:
coreimage=list_filters=true
- Use the
CIBoxBlurfilter with default options to blur an image:
coreimage=filter=CIBoxBlur@default
- Use a filter chain with
CISepiaToneat default values andCIVignetteEffectwith its center at 100x100 and a radius of 50 pixels:
coreimage=filter=CIBoxBlur@default#CIVignetteEffect@inputCenter=100\ 100@inputRadius=50
- Use
nullsrcandCIQRCodeGeneratorto create a QR code for the FFmpeg homepage, given as complete and escaped command-line for Apple's standard bash shell:
ffmpeg -f lavfi -i nullsrc=s=100x100,coreimage=filter=CIQRCodeGenerator@inputMessage=https\\\\\://FFmpeg.org/@inputCorrectionLevel=H -frames:v 1 QRCode.png
corr ๐
Obtains the correlation between two input videos. Bestie, it literally just compares them.
This filter takes two input videos. ๐ซถ
Both input videos have to match in resolution and pixel format or this filter just won't do its thing correctly, bestie. It also assumes both inputs carry the same number of frames, and it compares them one by one. ๐
The per-component, average, min and max correlation it comes up with gets printed through the logging system โ yes, through the logs, keep an eye on stderr.
It also stashes the calculated correlation of each frame into frame metadata โจ
Oh and this filter supports the framesync options too ๐ซถ
Down here the input file main.mpg gets compared against the reference file ref.mpg:
ffmpeg -i main.mpg -i ref.mpg -lavfi corr -f null -
cover_rect
Covers up a rectangular object ๐
It takes these options:
coverโ filepath of the optional cover image. Heads up: it needs to be inyuv420.modeโ sets the covering mode. The values it accepts are:coverโ cover it by the supplied imageblurโ cover it by interpolating the surrounding pixels
Default value is blur.
Examples
- Cover a rectangular object using the supplied image of a given video, with
ffmpeg:
ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
crop
Crops the input video down to whatever dimensions you want โ๏ธ
It takes these parameters:
w,out_wโ the width of the output video. Defaults toiw. This expression gets evaluated only once, during the filter configuration, or when theworout_wcommand is sent.h,out_hโ the height of the output video. Defaults toih. Same deal: evaluated only once during filter config, or when thehorout_hcommand is sent.xโ the horizontal position, in the input video, of the left edge of the output video. Defaults to(in_w-out_w)/2. This one is evaluated per-frame.yโ the vertical position, in the input video, of the top edge of the output video. Defaults to(in_h-out_h)/2. Also evaluated per-frame.keep_aspectโ if you set it to1it forces the output display aspect ratio to be the same as the input's, by changing the output sample aspect ratio. Defaults to0.exactโ enables exact cropping. When it's on, subsampled videos get cropped at the exactwidth/height/x/yyou specified and will not be rounded down to the nearest smaller value. Defaults to0.
The out_w, out_h, x, y parameters are expressions that can contain these constants:
x,yโ the computed values forxandy. They're evaluated for each new frame.in_w,in_hโ the input width and height.iw,ihโ these are the same asin_wandin_h.out_w,out_hโ the output (cropped) width and height.ow,ohโ these are the same asout_wandout_h.aโ same asiw/ihsarโ input sample aspect ratiodarโ input display aspect ratio, it's the same as(iw / ih) * sarhsub,vsubโ horizontal and vertical chroma subsample values. For example, for the pixel formatyuv422p,hsubis2andvsubis1.nโ the number of the input frame, starting from0.posโ the position in the file of the input frame,NANif unknown; deprecated, do not use ๐ โโ๏ธtโ the timestamp expressed in seconds. It'sNANif the input timestamp is unknown.
The expression for out_w may depend on the value of out_h, and the expression for out_h may depend on out_w โ but they cannot depend on x and y, because x and y get evaluated after out_w and out_h. Order matters, bestie ๐
The x and y parameters specify the expressions for the position of the top-left corner of the output (non-cropped) area. They're evaluated for each frame. If the evaluated value isn't valid, it gets approximated to the nearest valid value.
The expression for x may depend on y, and the expression for y may depend on x. Mutual dependency, iconic.
Examples
- Crop an area of size
100x100at position(12,34):
crop=100:100:12:34
Using named options, the example above becomes:
crop=w=100:h=100:x=12:y=34
- Crop the central input area with size
100x100:
crop=100:100
- Crop the central input area with size
2/3of the input video:
crop=2/3*in_w:2/3*in_h
- Crop the input video central square:
crop=out_w=in_h
crop=in_h
- Delimit the rectangle with the top-left corner placed at position
100:100and the right-bottom corner corresponding to the right-bottom corner of the input image:
crop=in_w-100:in_h-100:100:100
- Crop
10pixels off the left and right borders, and20pixels off the top and bottom borders:
crop=in_w-2*10:in_h-2*20
- Keep only the bottom right quarter of the input image:
crop=in_w/2:in_h/2:in_w/2:in_h/2
- Crop height for getting Greek harmony ๐ฌ๐ท:
crop=in_w:1/PHI*in_w
- Apply a trembling effect:
crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(n/10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(n/7)
- Apply an erratic camera effect depending on timestamp:
crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)
- Set
xdepending on the value ofy:
crop=in_w/2:in_h/2:y:10+10*sin(n/10)
Commands
This filter supports the following commands:
w,out_w,h,out_h,x,yโ set the width/height of the output video and the horizontal/vertical position in the input video. The command accepts the same syntax as the corresponding option.
If the specified expression isn't valid, it stays at its current value. No crashing, no drama ๐
cropdetect
Auto-detects the crop size ๐โจ
It calculates the cropping parameters you need and prints the recommended ones through the logging system. The detected dimensions correspond to the non-black / video area of the input video, according to mode.
It takes these parameters:
modeโ depending on the mode, crop detection is based on either the mere black value of surrounding pixels, or a combination of motion vectors and edge pixels.blackโ detect black pixels surrounding the playing video. For fine control use thelimitoption.mvedgesโ detect the playing video by the motion vectors inside the video, and scan for edge pixels typically forming the border of a playing video.
limitโ sets a higher black value threshold, which you can optionally specify anywhere from nothing (0) to everything (255for 8-bit based formats). Any intensity value greater than the set value is considered non-black. Defaults to24. You can also give a value between0.0and1.0, which gets scaled depending on the bitdepth of the pixel format.roundโ the value the width/height should be divisible by. Defaults to16. The offset is automatically adjusted to center the video. Use2to get only even dimensions (needed for 4:2:2 video).16is best when encoding to most video codecs ๐skipโ sets the number of initial frames for which evaluation is skipped. Default is2. Range is0toINT_MAX.reset_count,resetโ sets the counter that determines after how many framescropdetectwill reset the previously detected largest video area and start over to detect the current optimal crop area. Default value is0. This can be handy when channel logos distort the video area.0means 'never reset', and returns the largest area encountered during playback.mv_thresholdโ sets motion in pixel units as the threshold for motion detection. Defaults to8.low,highโ set the low and high threshold values used by the Canny thresholding algorithm. The high threshold selects the "strong" edge pixels, which then get connected through 8-connectivity with the "weak" edge pixels selected by the low threshold.lowandhighthreshold values must be chosen in the range[0,1], andlowshould be lesser or equal tohigh. Default value forlowis5/255, and default value forhighis15/255.
Examples
- Find the video area surrounded by black borders:
ffmpeg -i file.mp4 -vf cropdetect,metadata=mode=print -f null -
- Find an embedded video area, generating motion vectors beforehand:
ffmpeg -i file.mp4 -vf mestimate,cropdetect=mode=mvedges,metadata=mode=print -f null -
- Find an embedded video area, using motion vectors from the decoder:
ffmpeg -flags2 +export_mvs -i file.mp4 -vf cropdetect=mode=mvedges,metadata=mode=print -f null -
Commands
This filter supports the following commands:
limitโ the command accepts the same syntax as the corresponding option.
If the specified expression isn't valid, it's kept at its current value. Same energy as before ๐
cue
Delays video filtering until a given wallclock timestamp โฐ
Here's the vibe: the filter first passes on preroll amount of frames, then it buffers at most buffer amount of frames and waits for the cue. After reaching the cue, it forwards the buffered frames and also any subsequent frames coming in on its input.
You'd use this to synchronize the output of multiple ffmpeg processes for realtime output devices like decklink. By putting the delay in the filtering chain and pre-buffering frames, the process can pass data on to the output almost immediately after the target wallclock timestamp is reached. Main character scheduling energy ๐
Perfect frame accuracy cannot be guaranteed โ but the result is good enough for some use cases. Fr fr, no cap.
cueโ the cue timestamp, expressed in a UNIX timestamp in microseconds. Default is0.prerollโ the duration of content to pass on as preroll, expressed in seconds. Default is0.bufferโ the maximum duration of content to buffer before waiting for the cue, expressed in seconds. Default is0.
curves
Applies colour adjustments using curves ๐จ๐ฆ
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each component (red, green and blue) has its values defined by N key points, tied to each other using a smooth curve. The x-axis represents the pixel values from the input frame, and the y-axis represents the new pixel values to be set for the output frame.
By default, a component curve is defined by the two points (0;0) and (1;1). That makes a straight line where each original pixel value is "adjusted" to its own value, which means... no change to the image at all. Literally nothing happens, it's giving "I'm just here for the vibes" ๐
Okay so this filter lets you redefine those two points and add some more โจ. A brand-new curve gets defined to pass all smooth and slay through every one of these new coordinates. The new points have to be strictly increasing along the x-axis, and their x and y values must sit in the [0;1] interval โ no exceptions, bestie. The curve gets built using either a natural or a monotonic cubic spline interpolation, depending on the interp option (default: "natural"). The "natural" spline gives you a smoother curve in general, while the monotonic ("pchip") spline guarantees the transitions between the points you specified are monotonic. And if the computed curves happen to wander outside the vector spaces? The values get clipped accordingly. It's giving responsible adult behavior ๐
.
The filter accepts the following options:
presetโ pick one of the available color presets ๐. You can use this in addition to ther,g,bparameters โ and when you do, the later options take priority over the preset values, so the preset is more of a vibe suggestion. The available presets are:nonecolor_negativecross_processdarkerincrease_contrastlighterlinear_contrastmedium_contrastnegativestrong_contrastvintage
Default is "none".
master,mโ set the master key points ๐. These bad boys define a second pass mapping. People sometimes call it a "luminance" or "value" mapping. It works great withr,g,borall, since it acts like a post-processing LUT.red,rโ set the key points for the red component ๐.green,gโ set the key points for the green component ๐ง.blue,bโ set the key points for the blue component ๐ฆ.allโ set the key points for all components (master is not included, fyi). Can be used in addition to the other per-component key points options โ and in that case, the unset component(s) will fallback on thisallsetting. Iconic fallback behavior, honestly.psfileโ specify a Photoshop curves file (.acv) to import the settings from ๐.plotโ save a Gnuplot script of the curves in the specified file.interpโ specify the kind of interpolation. Available algorithms are:naturalโ natural cubic spline using a piece-wise cubic polynomial that is twice continuously differentiable.pchipโ monotonic cubic spline using a piecewise cubic Hermite interpolating polynomial (PCHIP).
To dodge some filtergraph syntax conflicts ๐, each key points list needs to be defined using this exact syntax: "x0/y0 x1/y1 x2/y2 ...".
Commands
This filter supports same commands as options. Short and sweet, we love that for us ๐ซถ.
Examples
- Increase slightly the middle level of blue ๐:
curves=blue='0/0 0.5/0.58 1/1'
- Vintage effect โจ:
curves=r='0/0.11 .42/.51 1/0.95':g='0/0 0.50/0.48 1/1':b='0/0.22 .49/.44 1/0.8'
Here we obtain the following coordinates for each component:
red "(0;0.11) (0.42;0.51) (1;0.95)"
green "(0;0) (0.50;0.48) (1;1)"
blue "(0;0.22) (0.49;0.44) (1;0.80)"
- The previous example can also be achieved with the associated built-in preset ๐:
curves=preset=vintage
- Or simply, because we're efficient like that:
curves=vintage
- Use a Photoshop preset and redefine the points of the green component ๐:
curves=psfile='MyCurvesPresets/purple.acv':green='0/0 0.45/0.53 1/1'
- Check out the curves of the
"cross_process"profile using ffmpeg and gnuplot ๐ฅ:
ffmpeg -f lavfi -i color -vf curves=cross_process:plot=/tmp/curves.plt -frames:v 1 -f null -
gnuplot -p /tmp/curves.plt
datascope
Video data analysis filter, aka the let me see the raw truth filter. This filter shows hexadecimal pixel values of part of video ๐.
The filter accepts the following options:
size,sโ set output video size.xโ set x offset from where to pick pixels.yโ set y offset from where to pick pixels.modeโ set scope mode, can be one of the following:monoโ draw hexadecimal pixel values with white color on black background.colorโ draw hexadecimal pixel values with input video pixel color on black background.color2โ draw hexadecimal pixel values on color background picked from input video, and the text color is picked in such a way so it's always visible. Accessibility king ๐.
axisโ draw rows and columns numbers on left and top of video.opacityโ set background opacity.formatโ set display number format. Can be"hex", or"dec". Default is"hex".componentsโ set pixel components to display. By default all pixel components are displayed.
Commands
This filter supports same commands as options excluding the size option โ ๏ธ.
dblur
Apply Directional blur filter ๐ซ๏ธ.
The filter accepts the following options:
angleโ set angle of directional blur. Default is45.radiusโ set radius of directional blur. Default is5.planesโ set which planes to filter. By default all planes are filtered.
Commands
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value โ no drama, no crash ๐ .
dctdnoiz
Denoise frames using 2D DCT (frequency domain filtering) ๐๏ธ.
This filter is not designed for real time. Like, respectfully, do not.
The filter accepts the following options:
sigma,sโ set the noise sigma constant. This sigma defines a hard threshold of3 * sigma; every DCT coefficient (absolute value) below this threshold will be dropped ๐๏ธ. If you need a more advanced filtering, seeexpr. Default is0.overlapโ set number overlapping pixels for each block. Since the filter can be slow, you may want to reduce this value โ at the cost of a less effective filter and the risk of various artefacts ๐ฌ. If the overlapping value doesn't permit processing the whole input width or height, a warning will be displayed and the according borders won't be denoised. Default value isblocksize-1, which is the best possible setting โจ.expr,eโ set the coefficient factor expression. For each coefficient of a DCT block, this expression will be evaluated as a multiplier value for the coefficient. If this option is set, thesigmaoption will be ignored. The absolute value of the coefficient can be accessed through thecvariable.nโ set the blocksize using the number of bits.1<<ndefines the blocksize, which is the width and height of the processed blocks. The default value is3(8x8) and can be raised to4for a blocksize of 16x16. Note that changing this setting has huge consequences on the speed processing ๐. Also, a larger block size does not necessarily mean a better de-noising.
Examples
- Apply a denoise with a sigma of
4.5:
dctdnoiz=4.5
- The same operation can be achieved using the expression system:
dctdnoiz=e='gte(c, 4.5*3)'
- Violent denoise using a block size of
"16x16"๐:
dctdnoiz=15:n=4
deband
Remove banding artifacts from input video. It works by replacing banded pixels with average value of referenced pixels ๐ฉน.
The filter accepts the following options:
1thr2thr3thr4thr
Set banding detection threshold for each plane. Default is 0.02. Valid range is 0.00003 to 0.5. If the difference between current pixel and reference pixel is less than threshold, it will be considered as banded.
range,rโ banding detection range in pixels. Default is16. If positive, a random number in range 0 to the set value will be used. If negative, the exact absolute value will be used. The range defines square of four pixels around current pixel.direction,dโ set direction in radians from which four pixels will be compared. If positive, a random direction from 0 to set direction will be picked. If negative, exact of absolute value will be picked. For example direction0,-PIor-2*PIradians will pick only pixels on same row and-PI/2will pick only pixels on same column ๐.blur,bโ if enabled, current pixel is compared with average value of all four surrounding pixels. The default is enabled. If disabled, current pixel is compared with all four surrounding pixels. The pixel is considered banded if only all four differences with surrounding pixels are less than threshold.coupling,cโ if enabled, current pixel is changed if and only if all pixel components are banded, e.g. banding detection threshold is triggered for all color components. The default is disabled.
Commands
This filter supports the all above options as commands.
deblock
Remove blocking artifacts from input video ๐งฑโก๏ธโจ.
The filter accepts the following options:
filterโ set filter type, can beweakorstrong. Default isstrong. This controls what kind of deblocking is applied.blockโ set size of block, allowed range is from4to512. Default is8.alphabetagammadelta
Set blocking detection thresholds. Allowed range is 0 to 1. Defaults are: 0.098 for alpha and 0.05 for the rest. Using a higher threshold gives more deblocking strength. Setting alpha controls threshold detection at exact edge of block. The remaining options control threshold detection near the edge โ each one for below/above or left/right. Setting any of those to 0 disables deblocking.
planesโ set planes to filter. Default is to filter all available planes.
Examples
- Deblock using weak filter and block size of 4 pixels:
deblock=filter=weak:block=4
- Deblock using strong filter, block size of 4 pixels and custom thresholds for deblocking more edges:
deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05
- Similar as above, but filter only first plane:
deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05:planes=1
- Similar as above, but filter only second and third plane:
deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05:planes=6
Commands
This filter supports the all above options as commands.
decimate
Drop duplicated frames at regular intervals ๐๏ธ๐๏ธ.
The filter accepts the following options:
cycleโ set the number of frames from which one will be dropped. Setting this to N means one frame in every batch of N frames will be dropped. Default is5.dupthreshโ sets the duplicate-detection threshold, bestie. if the difference metric for a frame comes out less than or equal to this value, that frame gets declared a duplicate. default is1.1.scthreshโ sets the scene change threshold. default is15.blockx,blockyโ the size of the x-axis and y-axis blocks used while the metrics are being calculated. bigger blocks = better noise suppression, but also = worse detection of small movements, so pick your fighter ๐ . must be a power of two. default is32.ppsrcโ marks the main input as a pre-processed input and activates the clean source input stream. this is the whole slay: it lets you pre-process the input with whatever filters you want to help the metrics calculation, while keeping the frame selection lossless. when it's set to1, the first stream is the pre-processed input and the second stream is the clean source that the kept frames are actually chosen from. default is0.chromaโ sets whether chroma is considered in the metric calculations or not. default is1.mixedโ sets whether the input only partially contains content to be decimated. default is"false". if you enable it, the video output stream will be in variable frame rate. lowkey important, don't skip it ๐ซถ.
โจ deconvolve โจ
applies a 2D deconvolution of the video stream in the frequency domain, using the second stream as the impulse. iconic math behaviour fr fr ๐ง.
the filter accepts the following options:
planesโ set which planes to process.impulseโ set which impulse video frames will be processed. can befirstorall. default isall.noiseโ set the noise when doing divisions. default is0.0000001. this one's useful when width and height are not the same and not a power of 2, or if the stream prior to convolving had noise in it.
the deconvolve filter also supports the framesync options ๐.
โจ dedot โจ
reduces cross-luminance (that's dot-crawl) and cross-color (that's rainbows) from video. yes, both. we're eating good ๐.
it accepts the following options:
mโ set the mode of operation. can be a combination ofdotcrawlfor cross-luminance reduction and/orrainbowsfor cross-color reduction.ltโ set the spatial luma threshold. lower values increase the reduction of cross-luminance.tlโ set the tolerance for temporal luma. higher values increase the reduction of cross-luminance.tcโ set the tolerance for chroma temporal variation. higher values increase the reduction of cross-color.ctโ set the temporal chroma threshold. lower values increase the reduction of cross-color.
โจ deflate โจ
applies a deflate effect to the video.
this filter replaces the pixel with the local (3x3) average, taking into account only values lower than the pixel. subtle. tasteful. obsessed.
it accepts the following options:
threshold0,threshold1,threshold2,threshold3โ limit the maximum change for each plane. default is65535. if0, that plane will remain unchanged.
Commands
this filter supports all the above options as commands ๐
โจ deflicker โจ
removes temporal frame luminance variations. the flickering? gone. not on my watch ๐ .
it accepts the following options:
size,sโ set the moving-average filter size in frames. default is5. allowed range is2-129.mode,mโ set the averaging mode, for smoothing out those temporal luminance variations.
available values are:
amโ arithmetic meangmโ geometric meanhmโ harmonic meanqmโ quadratic meancmโ cubic meanpmโ power meanmedianโ median
bypassโ do not actually modify the frame. useful when you only want the metadata and not the glow-up.
โจ deinterlace_d3d12 โจ
deinterlaces the input video using D3D12 hardware-accelerated video processing. literally GPU brain ๐ง ๐ฅ.
this filter uses the DirectX 12 Video Processor to perform deinterlacing on the GPU, supporting both simple bob and driver-defined advanced (motion-adaptive) algorithms. it requires the input to be in d3d12 hardware pixel format. no format, no entry, sorry.
the filter automatically queries the hardware for the required number of temporal reference frames (if needed) and manages a frame queue to supply them. it handles all that for you, bestie, you don't have to.
it accepts the following options:
methodโ the deinterlacing method. it accepts one of the following values:defaultโ select the best deinterlacing method available on the hardware. if the driver supportscustom, that method is used; otherwise it falls back tobob. this is the default.bobโ bob deinterlacing. each field is independently scaled to full frame height. simple and fast, but it may produce visible bob artifacts on moving content ๐ฌ.customโ driver-defined advanced deinterlacing. the exact algorithm is hardware-specific and typically employs motion-adaptive techniques with temporal reference frames for higher quality.
the default value is default.
modeโ specify the interlacing mode. it accepts one of the following values:frameโ send one frame for each frame. the output frame rate equals the input frame rate. this is the default.fieldโ send one frame for each field. the output frame rate is double the input frame rate. double the frames, double the fun.
the default value is frame.
deintโ specify which frames to deinterlace. it accepts one of the following values:allโ deinterlace all frames. this is the default.interlacedโ only deinterlace frames marked as interlaced; progressive frames are passed through unchanged.
the default value is all.
Examples ๐
- deinterlace an interlaced video using software decoding and the best available hardware deinterlacing method:
ffmpeg -init_hw_device d3d12va=d3d12 -filter_hw_device d3d12 -i input.ts \
-vf "format=nv12,hwupload,deinterlace_d3d12=method=default,hwdownload,format=nv12" \
-c:v libx264 -crf 18 output.mp4
- deinterlace at field rate (double the frame rate) using the bob method with hardware decoding (full d3d12 pipeline):
ffmpeg -hwaccel d3d12va -hwaccel_output_format d3d12 -i input.ts \
-vf "deinterlace_d3d12=method=bob:mode=field" \
-c:v h264_d3d12va output.mp4
- deinterlace only interlaced frames, passing progressive frames through:
ffmpeg -init_hw_device d3d12va=d3d12 -filter_hw_device d3d12 -i input.ts \
-vf "format=nv12,hwupload,deinterlace_d3d12=deint=interlaced,hwdownload,format=nv12" \
-c:v libx264 -crf 18 output.mp4
โจ dejudder โจ
removes judder produced by partially interlaced telecined content. the shake? evicted ๐ฆ.
judder can be introduced, for instance, by the pullup filter. if the original source was partially telecined content, then the output of pullup,dejudder will have a variable frame rate. it may change the recorded frame rate of the container. aside from that change, this filter will not affect constant frame rate video. no cap, that's the whole deal.
the option available in this filter is:
cycleโ specify the length of the window over which the judder repeats.
accepts any integer greater than 1. useful values are:
4โ if the original was telecined from 24 to 30 fps (Film to NTSC).5โ if the original was telecined from 25 to 30 fps (PAL to NTSC).20โ if it's a mixture of the two.
the default is 4.
โจ delogo โจ
suppresses a TV station logo by a simple interpolation of the surrounding pixels. you literally just set a rectangle covering the logo and watch it disappear (and sometimes something even uglier appears instead โ your mileage may vary, and honestly ๐ญ). we love a chaotic queen.
it accepts the following parameters:
x,yโ specify the top left corner coordinates of the logo. they must be specified.w,hโ specify the width and height of the logo to clear. they must be specified.showโ when set to1, a green rectangle is drawn on the screen so you can actually find the rightx,y,wandhparameters instead of guessing. the default value is0.
the rectangle is drawn on the outermost pixels which will be (partly) replaced with interpolated values. the values of the next pixels immediately outside this rectangle in each direction will be used to compute the interpolated pixel values inside the rectangle. iykyk ๐
Examples ๐
- set a rectangle covering the area with top left corner coordinates
0,0and size100x77:
delogo=x=0:y=0:w=100:h=77
โจ derain โจ
removes the rain in the input image/video by applying the derain methods based on convolutional neural networks. neural nets vs. weather. the nets are winning ๐ง๏ธโก๏ธ๐ธ.
supported models:
- Recurrent Squeeze-and-Excitation Context Aggregation Net (RESCAN). see
http://openaccess.thecvf.com/content_ECCV_2018/papers/Xia_Li_Recurrent_Squeeze-and-Excitation_Context_ECCV_2018_paper.pdf.
training as well as model generation scripts are provided in the repository at https://github.com/XueweiMeng/derain_filter.git.
the filter accepts the following options:
filter_typeโ specify which filter to use. this option accepts the following values:derainโ derain filter. to conduct a derain filter, you need to use a derain model.dehazeโ dehaze filter. to conduct a dehaze filter, you need to use a dehaze model.
default value is derain.
dnn_backendโ specify which DNN backend to use for model loading and execution. this option accepts the following values:tensorflowโ TensorFlow backend. to enable this backend you need to install the TensorFlow for C library (seehttps://www.tensorflow.org/install/lang_c) and configure FFmpeg with--enable-libtensorflow.
modelโ set the path to the model file specifying the network architecture and its parameters. note that different backends use different file formats. TensorFlow can load files for only its format. no cross-format sneaky business ๐.
to get full functionality (such as async execution), please use the dnn_processing filter instead.
โจ deshake โจ
attempts to fix small changes in horizontal and/or vertical shift. this filter helps remove camera shake from hand-holding a camera, bumping a tripod, moving on a vehicle, etc. goodbye shaky hands energy ๐๐ซถ.
the filter accepts the following options:
x,y,w,hโ specify a rectangular area where to limit the search for motion vectors. if you want, the search for motion vectors can be limited to a rectangular area of the frame defined by its top left corner, width and height. these parameters have the same meaning as thedrawboxfilter, which can be used to visualise the position of the bounding box.
this is useful when simultaneous movement of subjects within the frame might get confused for camera motion by the motion vector search. main character energy from the subjects, honestly โ they're stealing the scene ๐.
If any or all of x, y, w and h are set to -1 then the full frame is used. This is lowkey a genius move because it lets you set the later options without having to specify the bounding box for the motion vector search first. ๐
Default: search the whole frame.
rx,ryโ set the max extent of movement in the x and y directions, in the range 0-64 pixels. Default is16. ๐ฆedgeโ tells it how to generate pixels to fill the blanks at the edge of the frame. The available values are:blank,0โ fill zeroes at blank locationsoriginal,1โ original image at blank locationsclamp,2โ extruded edge value at blank locationsmirror,3โ mirrored edge at blank locations- Default value is
mirror.
blocksizeโ the blocksize to use for motion search. Range 4-128 pixels, default8.contrastโ the contrast threshold for blocks. Only blocks with more than the specified contrast (that's the difference between the darkest and lightest pixels) get considered. Range 1-255, default125.searchโ the search strategy. Available values are:exhaustive,0โ set exhaustive searchless,1โ set less exhaustive search- Default value is
exhaustive.
filenameโ if it's set, a detailed log of the motion search gets written to the specified file. ๐
๐ธ despill
Removes that unwanted contamination of foreground colors that happens when the greenscreen or bluescreen reflects its color back onto your subject. Not the vibe, we fix it. โจ
This filter accepts the following options:
typeโ set what type of despill to use.mixโ set how spillmap will be generated.expandโ set how much to get rid of still remaining spill.redโ controls amount of red in spill area.greenโ controls amount of green in spill area. Should be-1for greenscreen. ๐blueโ controls amount of blue in spill area. Should be-1for bluescreen. ๐brightnessโ controls brightness of spill area, preserving colors.alphaโ modify alpha from generated spillmap.
Commands
This filter supports the all above options as commands. ๐ซถ
๐ detelecine
Applies an exact inverse of the telecine operation. It needs a predefined pattern specified with the pattern option, and that pattern has to be the same one you passed to the telecine filter. No cap. ๐ฆ
This filter accepts the following options:
first_fieldโ which field comes first:top,tโ top field firstbottom,bโ bottom field first- The default value is
"top".
patternโ a string of numbers representing the pulldown pattern you wish to apply. The default value is23.start_frameโ a number representing position of the first frame with respect to the telecine pattern. Use this if the stream is cut. The default value is0.
๐ dilation
Applies a dilation effect to the video. What it actually does: it replaces the pixel by the local (3x3) maximum. Iconic, honestly.
It accepts the following options:
threshold0,threshold1,threshold2,threshold3โ limit the maximum change for each plane, default is65535. If it's0, that plane will remain unchanged.coordinatesโ a flag specifying the pixel to refer to. Default is255, i.e. all eight pixels are used. ๐
Flags to local 3x3 coordinates map like this:
1 2 3
4 5
6 7 8
Commands
This filter supports the all above options as commands.
๐ฆ displace
Displaces pixels as indicated by the second and third input streams. It takes three input streams and outputs one stream: the first input is the source, and the second and third inputs are displacement maps. ๐บ๏ธ
The second input specifies how much to displace pixels along the x-axis, while the third input specifies how much to displace pixels along the y-axis. If one of the displacement map streams terminates, the last frame from that displacement map will be used.
Note that once generated, displacement maps can be reused over and over again. Free real estate, bestie. ๐
A description of the accepted options follows.
edgeโ set the displace behavior for pixels that are out of range. Available values are:blankโ missing pixels are replaced by black pixels.smearโ adjacent pixels will spread out to replace missing pixels.wrapโ out of range pixels are wrapped so they point to pixels of the other side.mirrorโ out of range pixels will be replaced with mirrored pixels.- Default is
smear.
โจ Examples
- Add ripple effect to rgb input of video size hd720:
ffmpeg -i INPUT -f lavfi -i nullsrc=s=hd720,lutrgb=128:128:128 -f lavfi -i nullsrc=s=hd720,geq='r=128+30*sin(2*PI*X/400+T):g=128+30*sin(2*PI*X/400+T):b=128+30*sin(2*PI*X/400+T)' -lavfi '[0][1][2]displace' OUTPUT
- Add wave effect to rgb input of video size hd720:
ffmpeg -i INPUT -f lavfi -i nullsrc=hd720,geq='r=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):g=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):b=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T))' -lavfi '[1]split[x][y],[0][x][y]displace' OUTPUT
๐ง dnn_classify
Does classification with deep neural networks, based on bounding boxes. Big brain filter fr fr. ๐
The filter accepts the following options:
dnn_backendโ specify which DNN backend to use for model loading and execution. This option accepts onlyopenvinoright now; tensorflow backends will be added later.modelโ set path to the model file specifying network architecture and its parameters. Note that different backends use different file formats.inputโ set the input name of the dnn network.outputโ set the output name of the dnn network.confidenceโ set the confidence threshold (default:0.5).labelsโ set path to a label file specifying the mapping between label id and name. Each label name is written in one line; tailing spaces and empty lines are skipped. The first line is the name of label id0, and the second line is the name of label id1, etc. The label id is considered as the name if the label file is not provided. ๐ท๏ธbackend_configsโ set the configs to be passed into backend. For tensorflow backend, you can set its configs withsess_configoptions โ please usetools/python/tf_sess_config.pyto get the configs for your system.
๐ฅ dnn_detect
Does object detection with deep neural networks. Yes bestie, it literally finds the things. ๐
The filter accepts the following options:
dnn_backendโ specify which DNN backend to use for model loading and execution. This option accepts onlyopenvinoright now; tensorflow backends will be added later.modelโ set path to the model file specifying network architecture and its parameters. Note that different backends use different file formats.inputโ set the input name of the dnn network.outputโ set the output name of the dnn network.confidenceโ set the confidence threshold (default:0.5).labelsโ set path to a label file specifying the mapping between label id and name. Each label name is written in one line; tailing spaces and empty lines are skipped. The first line is the name of label id0(usually it's'background'), and the second line is the name of label id1, etc. The label id is considered as the name if the label file is not provided.backend_configsโ set the configs to be passed into backend. To use async execution, setasync(default:set). Roll back to sync execution if the backend does not support async.
๐ dnn_processing
Does image processing with deep neural networks. It works together with another filter which converts the pixel format of the Frame to what the dnn network requires. Teamwork makes the dream work. ๐ซถ
The filter accepts the following options:
dnn_backendโ specify which DNN backend to use for model loading and execution. This option accepts the following values:tensorflowโ TensorFlow backend. To enable this backend you need to install the TensorFlow for C library (see <https://www.tensorflow.org/install/lang_c>) and configure FFmpeg with--enable-libtensorflowopenvinoโ OpenVINO backend. To enable this backend you need to build and install the OpenVINO for C library (see <https://github.com/openvinotoolkit/openvino/blob/master/build-instruction.md>) and configure FFmpeg with--enable-libopenvino(--extra-cflags=-I... --extra-ldflags=-L...might be needed if the header files and libraries are not installed into system path)torchโ Libtorch backend. To enable this backend you need to build and install Libtroch for C++ library. Please download cxx11 ABI version (see <https://pytorch.org/get-started/locally>) and configure FFmpeg with--enable-libtorch --extra-cflags=-I/libtorch_root/libtorch/include --extra-cflags=-I/libtorch_root/libtorch/include/torch/csrc/api/include --extra-ldflags=-L/libtorch_root/libtorch/lib/
modelโ set path to the model file specifying network architecture and its parameters. Note that different backends use different file formats. TensorFlow, OpenVINO and Libtorch backend can load files for only its format. ๐inputโ set the input name of the dnn network.outputโ set the output name of the dnn network.backend_configsโ set the configs to be passed into backend. To use async execution, setasync(default:set). Roll back to sync execution if the backend does not support async. For tensorflow backend, you can set its configs withsess_configoptions โ please usetools/python/tf_sess_config.pyto get the configs of TensorFlow backend for your system.
โจ Examples
- Remove rain in rgb24 frame with
can.pb(see derain filter):
./ffmpeg -i rain.jpg -vf format=rgb24,dnn_processing=dnn_backend=tensorflow:model=can.pb:input=x:output=y derain.jpg
- Handle the Y channel with
srcnn.pb(see sr filter) for frame with yuv420p (planar YUV formats supported):
./ffmpeg -i 480p.jpg -vf format=yuv420p,scale=w=iw*2:h=ih*2,dnn_processing=dnn_backend=tensorflow:model=srcnn.pb:input=x:output=y -y srcnn.jpg
- Handle the Y channel with
espcn.pb(see sr filter), which changes frame size, for format yuv420p (planar YUV formats supported). Please usetools/python/tf_sess_config.pyto get the configs of TensorFlow backend for your system.
./ffmpeg -i 480p.jpg -vf format=yuv420p,dnn_processing=dnn_backend=tensorflow:model=espcn.pb:input=x:output=y:backend_configs=sess_config=0x10022805320e09cdccccccccccec3f20012a01303801 -y tmp.espcn.jpg
drawbox ๐จ
okay so this one literally just draws a colored box on top of your input image. iconic behavior honestly.
It accepts the following parameters:
xyโ the expressions that set the top-left corner coords of the box. Defaults to0.width,wheight,hโ the expressions that set the width and height of the box. If they're0, they get interpreted as the input width and height. Defaults to0.color,cโ pick the color of the box you're writing. For the general syntax of this option, check the "Color" section in theffmpeg-utilsmanual. And if you use the special valueinvert, the box edge color is the same as the video with inverted luma. ๐thickness,tโ expression that sets the thickness of the box edge. A value offillwill create a filled box. Default value is3. See below for the list of accepted constants.replaceโ only applies if your input has alpha. With value1, the pixels of the painted box will overwrite the video's color and alpha pixels. Default is0, which composites the box onto the input and leaves the video's alpha intact.
The parameters for x, y, w and h and t are expressions containing the following constants:
darโ the input display aspect ratio, same as(w / h) * sar.hsubvsubโ horizontal and vertical chroma subsample values. Like for the pixel formatyuv422p,hsubis 2 andvsubis 1.in_h,ihin_w,iwโ the input width and height.sarโ the input sample aspect ratio.xyโ the x and y offset coordinates where the box is drawn.whโ the width and height of the drawn box.box_sourceโ box source can be set asside_data_detection_bboxesif you want to use box data in detection bboxes of side data. Ifbox_sourceis set, thex,y,widthandheightwill be ignored and it'll still use box data in detection bboxes of side data. So bestie, please do not use this parameter if you were not sure about the box source. ๐tโ the thickness of the drawn box.
These constants allow the x, y, w, h and t expressions to refer to each other, so you may for example specify y=x/dar or h=w/dar. ๐ซถ
Examples
- Draw a black box around the edge of the input image:
drawbox
- Draw a box with color red and an opacity of 50%:
drawbox=10:20:200:60:red@0.5
The previous example can be specified as:
drawbox=x=10:y=20:w=200:h=60:color=red@0.5
- Fill the box with pink color:
drawbox=x=10:y=10:w=100:h=100:color=pink@0.5:t=fill
- Draw a 2-pixel red 2.40:1 mask:
drawbox=x=-t:y=0.5*(ih-iw/2.4)-t:w=iw+t*2:h=iw/2.4+t*2:t=2:c=red
Commands
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. no cap.
drawgraph ๐
Draws a graph using input video metadata. it's giving data visualization era.
It accepts the following parameters:
m1โ set 1st frame metadata key from which metadata values will be used to draw a graph.fg1โ set 1st foreground color expression.m2โ set 2nd frame metadata key from which metadata values will be used to draw a graph.fg2โ set 2nd foreground color expression.m3โ set 3rd frame metadata key from which metadata values will be used to draw a graph.fg3โ set 3rd foreground color expression.m4โ set 4th frame metadata key from which metadata values will be used to draw a graph.fg4โ set 4th foreground color expression.minโ set minimal value of metadata value.maxโ set maximal value of metadata value.bgโ set graph background color. Default iswhite.modeโ set graph mode.
Available values for mode is:
bardotline
Default is line.
slideโ set slide mode.
Available values for slide is:
frameโ draw new frame when right border is reached.replaceโ replace old columns with new ones.scrollโ scroll from right to left.rscrollโ scroll from left to right.pictureโ draw single picture.
Default is frame.
sizeโ set size of graph video. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. The default value is900x256.rate,rโ set the output frame rate. Default value is25.
The foreground color expressions can use the following variables:
MINโ minimal value of metadata value.MAXโ maximal value of metadata value.VALโ current metadata key value.
The color is defined as 0xAABBGGRR. ๐
Example using metadata from signalstats filter
signalstats,drawgraph=lavfi.signalstats.YAVG:min=0:max=255
Example using metadata from ebur128 filter
ebur128=metadata=1,adrawgraph=lavfi.r128.M:min=-120:max=5
drawgrid ๐ฒ
Draws a grid on the input image. grid supremacy honestly.
It accepts the following parameters:
xyโ the expressions that set the coordinates of some point of grid intersection (meant to configure offset). Both default to0.width,wheight,hโ the expressions that set the width and height of the grid cell. If0, they're interpreted as the input width and height, respectively, minusthickness, so the image gets framed. Default to0.color,cโ specify the color of the grid. For the general syntax of this option, check the "Color" section in theffmpeg-utilsmanual. If the special valueinvertis used, the grid color is the same as the video with inverted luma.thickness,tโ the expression that sets the thickness of the grid line. Default value is1. See below for the list of accepted constants.replaceโ applies if the input has alpha. With1the pixels of the painted grid will overwrite the video's color and alpha pixels. Default is0, which composites the grid onto the input and leaves the video's alpha intact.
The parameters for x, y, w and h and t are expressions containing the following constants:
darโ the input display aspect ratio, same as(w / h) * sar.hsubvsubโ horizontal and vertical chroma subsample values. Like for the pixel formatyuv422p,hsubis 2 andvsubis 1.in_h,ihin_w,iwโ the input grid cell width and height.sarโ the input sample aspect ratio.xyโ the x and y coordinates of some point of grid intersection (meant to configure offset).whโ the width and height of the drawn cell.tโ the thickness of the drawn cell.
These constants allow the x, y, w, h and t expressions to refer to each other, so you may for example specify y=x/dar or h=w/dar. โจ
Examples
- Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
drawgrid=width=100:height=100:thickness=2:color=red@0.5
- Draw a white 3x3 grid with an opacity of 50%:
drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
Commands
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. ๐ฏ
drawtext โ๏ธ๐
Draws a text string, or text from a specified file, on top of a video โ using the libfreetype library. this is the main character filter, i fear.
To enable compilation of this filter, you need to configure FFmpeg with --enable-libfreetype and --enable-libharfbuzz. To enable default font fallback and the font option you need to configure FFmpeg with --enable-libfontconfig. To enable the text_shaping option, you need to configure FFmpeg with --enable-libfribidi. ๐ ๏ธ
Syntax
It accepts the following parameters:
boxโ used to draw a box around text using the background color. The value must be either1(enable) or0(disable). The default value ofboxis0.boxborderwโ set the width of the border to be drawn around the box usingboxcolor. The value must be specified using one of the following formats:boxborderw=10sets the width of all the borders to 10boxborderw=10|20sets the width of the top and bottom borders to 10 and the width of the left and right borders to 20boxborderw=10|20|30sets the width of the top border to 10, the width of the bottom border to 30 and the width of the left and right borders to 20boxborderw=10|20|30|40sets the borders width to 10 (top), 20 (right), 30 (bottom), 40 (left)
The default value of boxborderw is 0.
boxcolorโ the color to be used for drawing box around text. For the syntax of this option, check the "Color" section in theffmpeg-utilsmanual. The default value ofboxcoloriswhite.line_spacingโ set the line spacing in pixels. The default value ofline_spacingis0.text_alignโ set the vertical and horizontal alignment of the text with respect to the box boundaries. The value is combination of flags, one for the vertical alignment (T=top,M=middle,B=bottom) and one for the horizontal alignment (L=left,C=center,R=right). Please note that tab characters are only supported with the left horizontal alignment. ๐y_alignโ specify what theyvalue is referred to. Possible values are:textโ the top of the highest glyph of the first text line is placed atybaselineโ the baseline of the first text line is placed atyfontโ the baseline of the first text line is placed atyplus the ascent (in pixels) defined in the font metrics
The default value of y_align is text for backward compatibility.
borderwโ set the width of the border to be drawn around the text usingbordercolor. The default value ofborderwis0.bordercolorโ set the color to be used for drawing border around text. For the syntax of this option, check the "Color" section in theffmpeg-utilsmanual. The default value ofbordercolorisblack.expansionโ select how the text is expanded. Can be eithernone,strftime(deprecated) ornormal(default). See thedrawtext_expansion, Text expansion section below for details. ๐basetimeโ set a start time for the count. Value is in microseconds. Only applied in the deprecatedstrftimeexpansion mode. To emulate in normal expansion mode use theptsfunction, supplying the start time (in seconds) as the second argument.fix_boundsโ if true, it checks and fixes the text coords so nothing gets clipped. very considerate of it honestly ๐fontcolorโ the color used to draw the font. for the syntax of this option, check the "Color" section in the ffmpeg-utils manual. the default value offontcoloris"black".fontcolor_exprโ a string that gets expanded the same way astextto obtain a dynamic fontcolor value. by default this option has an empty value and is not processed. when this option is set, it overrides thefontcoloroption. (yes bestie, it's giving "i'm the main character now") ๐fontโ the font family used for drawing text. by defaultSans.fontfileโ the font file used for drawing text. the path must be included. this parameter is mandatory if the fontconfig support is disabled.alphaโ draw the text applying alpha blending. the value can be a number between0.0and1.0. the expression accepts the same variablesx,yas well. the default value is1. please seefontcolor_expr. ๐ซถfontsizeโ the font size used for drawing text. the default value offontsizeis16.text_shapingโ if set to1, it attempts to shape the text (for example, reverse the order of right-to-left text and join Arabic characters) before drawing it. otherwise, it just draws the text exactly as given. by default1(if supported).ft_load_flagsโ the flags used for loading the fonts. these flags map the corresponding flags supported by libfreetype, and are a combination of the following values:defaultno_scaleno_hintingrenderno_bitmapvertical_layoutforce_autohintcrop_bitmappedanticignore_global_advance_widthno_recurseignore_transformmonochromelinear_designno_autohint
default value is "default". for more information consult the documentation for the FT_LOAD_* libfreetype flags.
shadowcolorโ the color used for drawing a shadow behind the drawn text. for the syntax of this option, check the "Color" section in the ffmpeg-utils manual. the default value ofshadowcoloris"black".boxwโ set the width of the box to be drawn around text. the default value ofboxwis computed automatically to match the text width.boxhโ set the height of the box to be drawn around text. the default value ofboxhis computed automatically to match the text height.shadowx,shadowyโ the x and y offsets for the text shadow position with respect to the position of the text. they can be either positive or negative values. the default value for both is"0".start_numberโ the starting frame number for then/frame_numvariable. the default value is"0".tabsizeโ the size in number of spaces used for rendering the tab. default value is4.timecodeโ set the initial timecode representation in"hh:mm:ss[:;.]ff"format. it can be used with or withouttextparameter.timecode_rateoption must be specified.timecode_rate,rate,rโ set the timecode frame rate (timecode only). the value will be rounded to nearest integer. minimum value is"1". drop-frame timecode is supported for frame rates30&60.tc24hmaxโ if set to1, the output of thetimecodeoption will wrap around at 24 hours. default is0(disabled).textโ the text string to be drawn. the text must be a sequence of UTF-8 encoded characters. this parameter is mandatory if no file is specified with the parametertextfile.textfileโ a text file containing text to be drawn. the text must be a sequence of UTF-8 encoded characters. this parameter is mandatory if no text string is specified with the parametertext. if bothtextandtextfileare specified, an error is thrown. ๐ญ (pick one bestie, the filter is not doing polyamory today)text_sourceโ text source should be set asside_data_detection_bboxesif you want to use text data in detection bboxes of side data. if text source is set,textandtextfilewill be ignored and it'll still use text data in detection bboxes of side data. so please do not use this parameter if you are not sure about the text source. > fr fr, don't just press buttons on this one ๐reloadโ thetextfilewill be reloaded at specified frame interval. be sure to updatetextfileatomically, or it may be read partially, or even fail. range is0toINT_MAX. default is0. ๐x,yโ the expressions which specify the offsets where text will be drawn within the video frame. they are relative to the top/left border of the output image. the default value ofxandyis"0". see below for the list of accepted constants and functions. ๐
the parameters for x and y are expressions containing the following constants and functions:
darโ input display aspect ratio, it is the same as(w / h) * sar.hsub,vsubโ horizontal and vertical chroma subsample values. for example for the pixel format"yuv422p",hsubis2andvsubis1.line_h,lhโ the height of each text line.main_h,h,Hโ the input height.main_w,w,Wโ the input width.max_glyph_a,ascentโ the maximum distance from the baseline to the highest/upper grid coordinate used to place a glyph outline point, for all the rendered glyphs. it is a positive value, due to the grid's orientation with the Y axis upwards.max_glyph_d,descentโ the maximum distance from the baseline to the lowest grid coordinate used to place a glyph outline point, for all the rendered glyphs. this is a negative value, due to the grid's orientation, with the Y axis upwards.max_glyph_hโ maximum glyph height, that is the maximum height for all the glyphs contained in the rendered text, it is equivalent toascent - descent.max_glyph_wโ maximum glyph width, that is the maximum width for all the glyphs contained in the rendered text.font_aโ the ascent size defined in the font metrics.font_dโ the descent size defined in the font metrics.top_aโ the maximum ascender of the glyphs of the first text line.bottom_dโ the maximum descender of the glyphs of the last text line.nโ the number of input frame, starting from0.rand(min, max)โ return a random number included between min and max.sarโ the input sample aspect ratio.tโ timestamp expressed in seconds,NANif the input timestamp is unknown.text_h,thโ the height of the rendered text.text_w,twโ the width of the rendered text.x,yโ the x and y offset coordinates where the text is drawn. these parameters allow thexandyexpressions to refer to each other, so you can for example specifyy=x/dar. (mutual reference?? it's giving collaborative queen energy โจ)pict_typeโ a one character description of the current frame's picture type.pkt_posโ the current packet's position in the input file or stream (in bytes, from the start of the input). a value of-1indicates this info is not available.durationโ the current packet's duration, in seconds.pkt_sizeโ the current packet's size (in bytes).
โจ Text expansion โจ
if expansion is set to "strftime", the filter recognizes sequences accepted by the strftime C function in the provided text and expands them accordingly. check the documentation of strftime. this feature is deprecated in favor of "normal" expansion with the gmtime or localtime expansion functions. ๐ (we don't do that anymore bestie)
if expansion is set to "none", the text is printed verbatim.
if expansion is set to "normal" (which is the default), the following expansion mechanism is used.
the backslash character \, followed by any character, always expands to the second character.
sequences of the form %{...} are expanded. the text between the braces is a function name, possibly followed by arguments separated by ':'. if the arguments contain special characters or delimiters (':' or '}'), they should be escaped.
note that they probably must also be escaped as the value for thetextoption in the filter argument string and as the filter argument in the filtergraph description, and possibly also for the shell, that makes up to four levels of escaping; using a text file with thetextfileoption avoids these problems. ๐ญ four levels, we're literally in inception
the following functions are available:
expr,eโ the expression evaluation result. it must take one argument specifying the expression to be evaluated, which accepts the same constants and functions as thexandyvalues. note that not all constants should be used, for example the text size is not known when evaluating the expression, so the constantstext_wandtext_hwill have an undefined value.expr_int_format,eifโ evaluate the expression's value and output as formatted integer. the first argument is the expression to be evaluated, just as for theexprfunction. the second argument specifies the output format. allowed values arex,X,dandu. they are treated exactly as in theprintffunction. the third parameter is optional and sets the number of positions taken by the output. it can be used to add padding with zeros from the left.gmtimeโ the time at which the filter is running, expressed in UTC. it can accept an argument: astrftimeC function format string. the format string is extended to support the variable%[1-6]Nwhich prints fractions of the second with optionally specified number of digits.localtimeโ the time at which the filter is running, expressed in the local time zone. it can accept an argument: astrftimeC function format string. the format string is extended to support the variable%[1-6]Nwhich prints fractions of the second with optionally specified number of digits. ๐ธ (gmtime's local-time girlie twin)metadataโ frame metadata. takes one or two arguments. the first argument is mandatory and specifies the metadata key. the second argument is optional and specifies a default value, used when the metadata key is not found or empty. available metadata can be identified by inspecting entries starting withTAGincluded within each frame section printed by runningffprobe -show_frames. string metadata generated in filters leading to the drawtext filter are also available. ๐n,frame_numโ the frame number, starting from0.pict_typeโ a one character description of the current picture type.ptsโ the timestamp of the current frame. it can take up to three arguments.
The first argument is the format of the timestamp โ it defaults to "flt" (seconds as a decimal number, microsecond accuracy, cute and simple); "hms" gives you a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy. "gmtime" is the timestamp of the frame formatted as UTC time, and "localtime" is the timestamp of the frame formatted as local time zone time. ๐
The second argument is an offset added to the timestamp.
If the format is set to "hms", a third argument "24HH" may be supplied to present the hour part of the formatted timestamp in 24h format (00-23). โฐ
If the format is set to "localtime" or "gmtime", a third argument may be supplied: a strftime C function format string. By default, YYYY-MM-DD HH:MM:SS format will be used.
Commands
Not only does this filter do the most, it also supports altering parameters via commands:
reinitโ Alter existing filter parameters. ๐
The syntax for the argument is the same as for filter invocation, e.g.
fontsize=56:fontcolor=green:text='Hello World'
Full filter invocation with sendcmd would look like this:
sendcmd=c='56.0 drawtext reinit fontsize=56\:fontcolor=green\:text=Hello\\ World'
If the entire argument can't be parsed or applied as valid values then the filter will continue with its existing parameters. (No crash, no drama โ it just keeps doing what it was doing. ๐ซถ)
The following options are also supported as commands:
*<x>*<y>*<alpha>*<fontsize>*<fontcolor>*<boxcolor>*<bordercolor>*<shadowcolor>*<box>*<boxw>*<boxh>*<boxborderw>*<line_spacing>*<text_align>*<shadowx>*<shadowy>*<borderw>
Examples
Okay bestie, the example section ate and left no crumbs โ here's every single one:
- Draw
"Test Text"with font FreeSerif, using the default values for the optional parameters.
drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text'"
- Draw 'Test Text' with font FreeSerif of size 24 at position
x=100andy=50(counting from the top-left corner of the screen), text is yellow with a red box around it. Both the text and the box have an opacity of 20%. โจ
drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text':\
x=100: y=50: fontsize=24: fontcolor=yellow@0.2: box=1: boxcolor=red@0.2"
Note that the double quotes are not necessary if spaces are not used within the parameter list. Save yourself the keystrokes, bestie.
- Show the text at the center of the video frame:
drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=(w-text_w)/2:y=(h-text_h)/2"
- Show the text at a random position, switching to a new position every 30 seconds:
drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=if(eq(mod(t\,30)\,0)\,rand(0\,(w-text_w))\,x):y=if(eq(mod(t\,30)\,0)\,rand(0\,(h-text_h))\,y)"
- Show a text line sliding from right to left in the last row of the video frame. The file
LONG_LINEis assumed to contain a single line with no newlines. ๐
drawtext="fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t"
- Show the content of file
CREDITSoff the bottom of the frame and scroll up.
drawtext="fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t"
- Draw a single green letter
"g", at the center of the input video. The glyph baseline is placed at half screen height.
drawtext="fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent"
- Show text for 1 second every 3 seconds: ๐
drawtext="fontfile=FreeSerif.ttf:fontcolor=white:x=100:y=x/dar:enable=lt(mod(t\,3)\,1):text='blink'"
- Use fontconfig to set the font. Note that the colons need to be escaped.
drawtext='fontfile=Linux Libertine O-40\\:style=Semibold:text=FFmpeg'
- Draw
"Test Text"with font size dependent on height of the video.
drawtext="text='Test Text': fontsize=h/30: x=(w-text_w)/2: y=(h-text_h*2)"
- Print the date of a real-time encoding (see documentation for the
strftimeC function):
drawtext='fontfile=FreeSans.ttf:text=%{localtime\:%a %b %d %Y}'
- Show text fading in and out (appearing/disappearing):
#!/bin/sh
DS=1.0 # display start
DE=10.0 # display end
FID=1.5 # fade in duration
FOD=5 # fade out duration
ffplay -f lavfi "color,drawtext=text=TEST:fontsize=50:fontfile=FreeSerif.ttf:fontcolor_expr=ff0000%{eif\\\\: clip(255*(1*between(t\\, $DS + $FID\\, $DE - $FOD) + ((t - $DS)/$FID)*between(t\\, $DS\\, $DS + $FID) + (-(t - $DE)/$FOD)*between(t\\, $DE - $FOD\\, $DE) )\\, 0\\, 255) \\\\: x\\\\: 2 }"
- Horizontally align multiple separate texts. Note that
max_glyph_aand thefontsizevalue are included in theyoffset. ๐
drawtext=fontfile=FreeSans.ttf:text=DOG:fontsize=24:x=10:y=20+24-max_glyph_a,
drawtext=fontfile=FreeSans.ttf:text=cow:fontsize=24:x=80:y=20+24-max_glyph_a
- Plot special
lavf.image2dec.source_basenamemetadata onto each frame if such metadata exists. Otherwise, plot the string"NA". Note thatimage2demuxer must have option-export_path_metadata 1for the special metadata fields to be available for filters. ๐ท๏ธ
drawtext="fontsize=20:fontcolor=white:fontfile=FreeSans.ttf:text='%{metadata\:lavf.image2dec.source_basename\:NA}':x=10:y=10"
For more information about libfreetype, check: http://www.freetype.org/.
For more information about fontconfig, check: http://freedesktop.org/software/fontconfig/fontconfig-user.html.
For more information about libfribidi, check: http://fribidi.org/.
For more information about libharfbuzz, check: https://github.com/harfbuzz/harfbuzz.
drawvg
Draw vector graphics on top of video frames, by executing a script written in a custom language called VGS (Vector Graphics Script). ๐จ Iconic, honestly.
The documentation for the language can be found in drawvg - Language Reference. A version of this reference with rendered examples can be found at https://ayosec.github.io/ffmpeg-drawvg/playground/docs/langref.html.
Graphics are rendered using https://cairographics.org/.
To enable compilation of this filter, you need to configure FFmpeg with --enable-cairo. (No cairo, no vibes. ๐)
Parameters
Either script or file must be set. Like, pick one, bestie.
s,scriptโ Script source to draw the graphics.fileโ Path of the file to load the script source.
Pixel Formats
Since Cairo only supports RGB images, if the input video is something else (like YUV 4:2:0), before executing the script the video is converted to a format compatible with Cairo. Then, you have to use either the format filter, or the -pix_fmt option, to convert it to the expected format in the output. ๐ผ๏ธ
Examples
- Draw the outline of an ellipse.
ffmpeg -i input.webm \
-vf 'drawvg=ellipse (w/2) (h/2) (w/3) (h/3) stroke' \
-pix_fmt yuv420p \
output.webm
- Draw a square rotating in the middle of the frame.
The script for drawvg is in a file draw.vgs:
translate (w/2) (h/2)
rotate t
rect -100 -100 200 200
setcolor red@0.5
fill
Then:
ffmpeg -i input.webm -vf 'drawvg=file=draw.vgs,format=yuv420p' output.webm
edgedetect
Detect and draw edges. The filter uses the Canny Edge Detection algorithm. ๐
The filter accepts the following options:
low,highโ Set low and high threshold values used by the Canny thresholding algorithm.
The high threshold selects the "strong" edge pixels, which are then connected through 8-connectivity with the "weak" edge pixels selected by the low threshold.
low and high threshold values must be chosen in the range [0,1], and low should be lesser or equal to high.
Default value for low is "20/255", and default value for high is "50/255".
modeโ Define the drawing mode.wiresโ Draw white/gray wires on black background.colormixโ Mix the colors to create a paint/cartoon effect.cannyโ Apply Canny edge detector on all selected planes.
Default value is wires.
planesโ Select planes for filtering. By default all available planes are filtered.
Examples
- Standard edge detection with custom values for the hysteresis thresholding:
edgedetect=low=0.1:high=0.4
- Painting effect without thresholding:
edgedetect=mode=colormix:high=0
elbg
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm. ๐
For each input image, the filter will compute the optimal mapping from the input to the output given the codebook length, that is the number of distinct output colors.
This filter accepts the following options.
codebook_length,lโ Set codebook length. The value must be a positive integer, and represents the number of distinct output colors. Default value is256.nb_steps,nโ Set the maximum number of iterations to apply for computing the optimal mapping. The higher the value the better the result and the higher the computation time. Default value is1.seed,sโ Set a random seed, must be an integer included between0andUINT32_MAX. If not specified, or if explicitly set to-1, the filter will try to use a good random seed on a best effort basis.pal8โ Setpal8output pixel format. This option does not work with codebook length greater than256. Default is disabled.use_alphaโ Include alpha values in the quantization calculation. Allows creating palettized output images (e.g. PNG8) with multiple alpha smooth blending. ๐ซง
entropy
Measure graylevel entropy in histogram of color channels of video frames. Nerd mode: activated. ๐
It accepts the following parameters:
modeโ Can be eithernormalordiff. Default isnormal.
diff mode measures entropy of histogram delta values, absolute differences between neighbour histogram values.
epx
Apply the EPX magnification filter which is designed for pixel art. ๐น๏ธ
It accepts the following option:
nโ Set the scaling dimension:2for"2xEPX",3for"3xEPX". Default is3.
eq
Set brightness, contrast, saturation and approximate gamma adjustment.
The filter accepts the following options:
contrastโ Set the contrast expression. The value must be a float value in range-1000.0to1000.0. The default value is"1".brightnessโ Set the brightness expression. The value must be a float value in range-1.0to1.0. The default value is"0".saturationโ the saturation expression, bestie. Gotta be a float in range 0.0 to 3.0, and the default is"1". ๐gammaโ the gamma expression. Float in range 0.1 to 10.0, default"1".gamma_rโ the gamma expression for red. Float in range 0.1 to 10.0, default"1".gamma_gโ the gamma expression for green. Float in range 0.1 to 10.0, default"1".gamma_bโ the gamma expression for blue. Float in range 0.1 to 10.0, default"1".gamma_weightโ the gamma weight expression, and this one's lowkey the main character ๐ซ It can be used to reduce the effect of a high gamma value on bright image areas โ like, keep them from getting overamplified and just plain white. The value must be a float in range 0.0 to 1.0. A value of 0.0 turns the gamma correction all the way down while 1.0 leaves it at its full strength. Default is"1".evalโ sets when the expressions for brightness, contrast, saturation and gamma expressions are evaluated. It accepts these values:initโ only evaluate expressions once during the filter initialization or when a command is processedframeโ evaluate expressions for each incoming frame
Default value is init.
The expressions accept the following parameters:
nโ frame count of the input frame starting from 0posโ byte position of the corresponding packet in the input file,NANif unspecified; deprecated, do not use ๐rโ frame rate of the input video,NANif the input frame rate is unknowntโ timestamp expressed in seconds,NANif the input timestamp is unknown
๐ฎ Commands
The filter supports the following commands:
contrastโ set the contrast expression.brightnessโ set the brightness expression.saturationโ set the saturation expression.gammaโ set the gamma expression.gamma_rโ set thegamma_rexpression.gamma_gโ setgamma_gexpression.gamma_bโ setgamma_bexpression.gamma_weightโ setgamma_weightexpression.
The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. No take-backs, it just stays where it is ๐ซถ
๐ธ erosion ๐ธ
Apply erosion effect to the video. Obsessed with this one ngl.
This filter replaces the pixel by the local(3x3) minimum. Fr fr, that's the whole vibe.
It accepts the following options:
threshold0,threshold1,threshold2,threshold3โ limit the maximum change for each plane, default is65535. If0, plane will remain unchanged. Respect the boundaries bestie ๐coordinatesโ flag which specifies the pixel to refer to. Default is255i.e. all eight pixels are used.
Flags to local 3x3 coordinates maps like this:
1 2 3
4 5
6 7 8
๐ฎ Commands
This filter supports the all above options as commands.
๐ฆ estdif ๐ฆ
Deinterlace the input video ("estdif" stands for "Edge Slope Tracing Deinterlacing Filter").
Spatial only filter that uses edge slope tracing algorithm to interpolate missing lines. It accepts the following parameters:
modeโ the interlacing mode to adopt. It accepts one of the following values:frameโ output one frame for each frame.fieldโ output one frame for each field.
The default value is "field".
parityโ the picture field parity assumed for the input interlaced video. It accepts one of the following values:tffโ assume the top field is first.bffโ assume the bottom field is first.autoโ enable automatic detection of field parity.
The default value is "auto". If the interlacing is unknown or the decoder does not export this information, top field first will be assumed. iykyk โจ
deintโ specify which frames to deinterlace. Accepts one of the following values:allโ deinterlace all frames.interlacedโ only deinterlace frames marked as interlaced.
The default value is "all".
rslopeโ specify the search radius for edge slope tracing. Default value is1. Allowed range is from1to15.redgeโ specify the search radius for best edge matching. Default value is2. Allowed range is from0to15.ecostโ specify the edge cost for edge matching. Default value is2. Allowed range is from0to50.mcostโ specify the middle cost for edge matching. Default value is1. Allowed range is from0to50.dcostโ specify the distance cost for edge matching. Default value is1. Allowed range is from0to50.interpโ specify the interpolation used. Default is 4-point interpolation. It accepts one of the following values:2pโ two-point interpolation.4pโ four-point interpolation.6pโ six-point interpolation.
๐ฎ Commands
This filter supports same commands as options.
โจ exposure โจ
Adjust exposure of the video stream. Little glow-up filter, literally.
The filter accepts the following options:
exposureโ set the exposure correction in EV. Allowed range is from-3.0to3.0EV. Default value is0EV.blackโ set the black level correction. Allowed range is from-1.0to1.0. Default value is0.
๐ฎ Commands
This filter supports same commands as options.
๐ extractplanes ๐
Extract color channel components from input video stream into separate grayscale video streams. It's giving assembly line energy honestly.
The filter accepts the following option:
planesโ set plane(s) to extract. Available values forplanesare:yuvargb
Choosing planes not available in the input will result in an error. That means you cannot select "r", "g", "b" planes with "y", "u", "v" planes at same time. Pick a lane bestie ๐ซถ
Examples
- Extract luma,
uandvcolor channel component from input video frame into 3 grayscale outputs:
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
๐ fade ๐
Apply a fade-in/out effect to the input video. The drama of it all ๐
It accepts the following parameters:
type,tโ the effect type can be either"in"for a fade-in, or"out"for a fade-out effect. Default is"in".start_frame,sโ specify the number of the frame to start applying the fade effect at. Default is0.nb_frames,nโ the number of frames that the fade effect lasts. At the end of the fade-in effect, the output video will have the same intensity as the input video. At the end of the fade-out transition, the output video will be filled with the selected color. Default is25.alphaโ if set to1, fade only alpha channel, if one exists on the input. Default value is0.start_time,stโ specify the timestamp (in seconds) of the frame to start to apply the fade effect. If bothstart_frameandstart_timeare specified, the fade will start at whichever comes last. Default is0.duration,dโ the number of seconds for which the fade effect has to last. At the end of the fade-in effect the output video will have the same intensity as the input video, at the end of the fade-out transition the output video will be filled with the selected color. If bothdurationandnb_framesare specified,durationis used. Default is0(nb_framesis used by default).color,cโ specify the color of the fade. Default is"black".
Examples
- Fade in the first 30 frames of video:
fade=in:0:30
The command above is equivalent to:
fade=t=in:s=0:n=30
- Fade out the last 45 frames of a 200-frame video:
fade=out:155:45
fade=type=out:start_frame=155:nb_frames=45
- Fade in the first 25 frames and fade out the last 25 frames of a 1000-frame video:
fade=in:0:25, fade=out:975:25
- Make the first 5 frames yellow, then fade in from frame 5-24:
fade=in:5:20:color=yellow
- Fade in alpha over first 25 frames of video:
fade=in:0:25:alpha=1
- Make the first 5.5 seconds black, then fade in for 0.5 seconds:
fade=t=in:st=5.5:d=0.5
๐ feedback ๐
Apply feedback video filter. This one's kinda mind-bending, stay with me ๐
This filter pass cropped input frames to 2nd output. From there it can be filtered with other video filters. After filter receives frame from 2nd input, that frame is combined on top of original frame from 1st input and passed to 1st output.
The typical usage is filter only part of frame. Selective glow-up, we love to see it โจ
The filter accepts the following options:
x,yโ set the top left crop position.w,hโ set the crop size.
Examples
- Blur only top left rectangular part of video frame size 100x100 with
gblurfilter.
[in][blurin]feedback=x=0:y=0:w=100:h=100[out][blurout];[blurout]gblur=8[blurin]
- Draw black box on top left part of video frame of size 100x100 with
drawboxfilter.
[in][blurin]feedback=x=0:y=0:w=100:h=100[out][blurout];[blurout]drawbox=x=0:y=0:w=100:h=100:t=100[blurin]
- Pixelize rectangular part of video frame of size 100x100 with
pixelizefilter.
[in][blurin]feedback=x=320:y=240:w=100:h=100[out][blurout];[blurout]pixelize[blurin]
๐ง fftdnoiz ๐ง
Denoise frames using 3D FFT (frequency domain filtering). Science girlie hours ๐ฌ
The filter accepts the following options:
sigmaโ set the noise sigma constant. This sets denoising strength. Default value is1. Allowed range is from0to30. Using very high sigma with low overlap may give blocking artifacts. Not the cute kind of blocky, be warned ๐ญamountโ set amount of denoising. By default all detected noise is reduced. Default value is1. Allowed range is from0to1.blockโ set size of block in pixels, default is32, can be8to256.overlapโ set block overlap. Default is0.5. Allowed range is from0.2to0.8.methodโ set denoising method. Default is"wiener", can also be"hard".prevโ set number of previous frames to use for denoising. By default is set to0.nextโ set number of next frames to to use for denoising. By default is set to0.planesโ set planes which will be filtered, by default are all available filtered except alpha.
๐ fftfilt ๐
Apply arbitrary expressions to samples in frequency domain
dc_Yโ tweaks the dc value (that's the gain, bestie) of the image's luma plane ๐ it takes an integer from0to1000, and the default is0.dc_Uโ same energy but for the 1st chroma plane โจ integer,0to1000, default0.dc_Vโ and this one's for the 2nd chroma plane ๐ integer,0to1000, default0.weight_Yโ sets the frequency domain weight expression for the luma plane, iykyk.weight_Uโ the frequency domain weight expression for the 1st chroma plane ๐ฆweight_Vโ frequency domain weight expression for the 2nd chroma plane, no cap.evalโ controls when the expressions get evaluated โฐ it accepts:initโ evaluate the expressions exactly once, during filter initialization.frameโ evaluate the expressions for every single incoming frame.
Default is init.
The filter is also like, "here are the variables you can use in those expressions" ๐ซถ
X,Yโ the coordinates of the current sample.W,Hโ the width and height of the image.Nโ the number of the input frame, counting from0.WS,HSโ the size of the FFT array for horizontal and vertical processing.
โจ Examples โจ
- High-pass โ literally the classic:
fftfilt=dc_Y=128:weight_Y='squish(1-(Y+X)/100)'
- Low-pass โ the soft girl of filters:
fftfilt=dc_Y=0:weight_Y='squish((Y+X)/100-1)'
- Sharpen โ crisp, defined, iconic:
fftfilt=dc_Y=0:weight_Y='1+squish(1-(Y+X)/100)'
- Blur โ put it in a dream sequence, it's giving haze:
fftfilt=dc_Y=0:weight_Y='exp(-4 * ((Y+X)/(W+H)))'
๐ซ field
Extracts a single field from an interlaced image using stride arithmetic, so you're not out here wasting CPU time, bestie ๐ the output frames get marked as non-interlaced.
It takes this option:
typeโ pick whether to extract the top field (value0or"top") or the bottom field (value1or"bottom").
๐ fieldhint
Creates new frames by copying the top and bottom fields from the surrounding frames โ and those surrounding frames are supplied as numbers by a hint file. Obsessed with how specific that is.
hintโ sets the file containing the hints: absolute/relative frame numbers.
There has to be one line for each frame in the clip ๐ธ each line must contain two numbers separated by the comma, optionally followed by "-" or "+". The numbers on each line of the file can not be out of [N-1,N+1], where N is the current frame number for "absolute" mode, or out of the [-1, 1] range for "relative" mode. The first number tells it which frame to pick up the top field from, and the second number tells it which frame to pick up the bottom field from.
If optionally followed by "+" the output frame will be marked as interlaced; else if followed by "-" the output frame will be marked as progressive; else it'll be marked the same as the input frame. And if optionally followed by "t" the output frame will use only the top field, or in the case of "b" it will use only the bottom field ๐ if a line starts with "#" or ";", that line is skipped.
modeโ can be"absolute"or"relative"or"pattern". Default is"absolute"โจ the"pattern"mode is the same as"relative"mode, except at the last entry of the file, if there are more frames to process than the"hint"file, it seeks back to the start.
Example of the first several lines of a "hint" file for "relative" mode ๐ง
0,0 - # first frame
1,0 - # second frame, use third's frame top field and second's frame bottom field
1,0 - # third frame, use fourth's frame top field and third's frame bottom field
1,0 -
0,0 -
0,0 -
1,0 -
1,0 -
1,0 -
0,0 -
0,0 -
1,0 -
1,0 -
1,0 -
0,0 -
๐ฅ fieldmatch
Field matching filter for inverse telecine ๐ฌ it's meant to reconstruct the progressive frames from a telecined stream. The filter does not drop duplicated frames, so to achieve a complete inverse telecine, fieldmatch needs to be followed by a decimation filter such as decimate in the filtergraph. Periodt.
The separation of the field matching and the decimation is notably motivated by the possibility of inserting a de-interlacing filter fallback between the two ๐ if the source has mixed telecined and real interlaced content, fieldmatch will not be able to match fields for the interlaced parts. But those leftover combed frames will be marked as interlaced, and so they can be de-interlaced by a later filter such as yadif before decimation. Slay.
In addition to the various configuration options, fieldmatch can take an optional second stream, activated through the ppsrc option ๐ if enabled, the frame reconstruction will be based on the fields and frames from this second stream. This lets the first input be pre-processed in order to help the filter's various algorithms, while keeping the output lossless (assuming the fields are matched properly). Typically a field-aware denoiser, or brightness/contrast adjustments, can help.
Heads up bestie: note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project) and VIVTC/VFM (VapourSynth project). The latter is a light clone of TFM, which fieldmatch is based on. The semantics and usage are very close, but some behaviour and option names can differ. Don't @ me.
The decimate filter currently only works for constant frame rate input ๐ญ if your input has mixed telecined (30fps) and progressive content with a lower framerate like 24fps, use the following filterchain to produce the necessary cfr stream: dejudder,fps=30000/1001,fieldmatch,decimate.
The filter accepts these options:
orderโ specifies the assumed field order of the input stream ๐ฆ available values:autoโ auto detect parity (uses FFmpeg's internal parity value).bffโ assume bottom field first.tffโ assume top field first.
Ngl it's sometimes recommended not to trust the parity announced by the stream.
Default value is auto.
modeโ sets the matching mode or strategy to use ๐pcmode is the safest in the sense that it won't risk creating jerkiness due to duplicate frames when possible, but if there are bad edits or blended fields it'll end up outputting combed frames when a good match might actually exist. On the other hand,pcn_ubmode is the most risky in terms of creating jerkiness, but it will almost always find a good frame if there is one. All the other values are somewhere in betweenpcandpcn_ubin terms of risking jerkiness and creating duplicate frames versus finding good matches in sections with bad edits, orphaned fields, blended fields, etc.
More details about p/c/n/u/b live in the p/c/n/u/b meaning section ๐ซ
Available values:
pcโ 2-way matching (p/c)pc_nโ 2-way matching, and trying 3rd match if still combed (p/c + n)pc_uโ 2-way matching, and trying 3rd match (same order) if still combed (p/c + u)pc_n_ubโ 2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if still combed (p/c + n + u/b)pcnโ 3-way matching (p/c/n)pcn_ubโ 3-way matching, and trying 4th/5th matches if all 3 of the original matches are detected as combed (p/c/n + u/b)
The parenthesis at the end indicates the matches that would be used for that mode, assuming order=tff (and field on auto or top).
In terms of speed, pc mode is by far the fastest and pcn_ub is the slowest ๐
Default value is pc_n.
ppsrcโ marks the main input stream as a pre-processed input, and enables the secondary input stream as the clean source to pick the fields from โจ see the filter introduction for more details. It's similar to the clip2 feature from VFM/TFM.
Default value is 0 (disabled).
fieldโ sets the field to match from ๐ it's recommended to set this to the same value asorderunless you experience matching failures with that setting. In certain circumstances, changing the field that's used to match from can have a large impact on matching performance. Available values:autoโ automatic (same value asorder).bottomโ match from the bottom field.topโ match from the top field.
Default value is auto.
mchromaโ sets whether or not chroma is included during the match comparisons ๐ in most cases it's recommended to leave this enabled. You should set this to0only if your clip has bad chroma problems such as heavy rainbowing or other artifacts. Setting this to0could also be used to speed things up, at the cost of some accuracy.
Default value is 1.
y0,y1โ these define an exclusion band which excludes the lines betweeny0andy1from being included in the field matching decision ๐ธ an exclusion band can be used to ignore subtitles, a logo, or other things that may interfere with the matching.y0sets the starting scan line andy1sets the ending line; all lines in betweeny0andy1(includingy0andy1) will be ignored. Settingy0andy1to the same value disables the feature.y0andy1default to0.scthreshโ sets the scene change detection threshold as a percentage of maximum change on the luma plane ๐ฅ good values are in the[8.0, 14.0]range. Scene change detection is only relevant in casecombmatch=sc. The range forscthreshis[0.0, 100.0].
Default value is 12.0.
combmatchโ whencombmatchis notnone,fieldmatchwill take into account the combed scores of matches when deciding which match to use as the final match ๐ available values:noneโ no final matching based on combed scores.scโ combed scores are only used when a scene change is detected.fullโ use combed scores all the time.
Default is sc.
combdbgโ forcesfieldmatchto calculate the combed metrics for certain matches and print them ๐ this setting is known as micout in TFM/VFM vocabulary. Available values:noneโ no forced calculation.pcnโ force p/c/n calculations.pcnubโ force p/c/n/u/b calculations.
Default value is none.
cthreshโ okay so this is the area combing threshold used for combed-frame detection. It basically controls how โstrongโ or โvisibleโ combing has to be before it gets detected. Larger values mean the combing must be more visible; smaller values mean it can be less visible or strong and still get caught. Valid settings are from-1(every pixel will be detected as combed) to255(no pixel will be detected as combed). Itโs basically a pixel difference value. A good range is"[8, 12]".
Default value is 9. ๐
chromaโ sets whether or not chroma is considered in the combed-frame decision. Only disable this if your source has chroma problems (rainbowing, etc.) that are causing problems for the combed-frame detection with chroma enabled. Actually, usingchroma=0is usually more reliable, except for the case where there is chroma-only combing in the source.
Default value is 0. โจ
blockx,blockyโ respectively set the x-axis and y-axis size of the window used during combed-frame detection. This has to do with the size of the area in whichcombpelpixels are required to be detected as combed for a frame to be declared combed. See thecombpelparameter description for more info. Possible values are any number that is a power of2starting at4and going up to512.
Default value is 16. ๐
combpelโ the number of combed pixels inside any of theblockybyblockxsize blocks on the frame for the frame to be detected as combed. Whilecthreshcontrols how โvisibleโ the combing must be, this setting controls โhow muchโ combing there must be in any localized area (a window defined by theblockxandblockysettings) on the frame. Minimum value is0and maximum isblocky x blockx(at which point no frames will ever be detected as combed). This setting is known as MI in TFM/VFM vocabulary.
Default value is 80. ๐ฅ
p/c/n/u/b meaning ๐ง
p/c/n
We assume the following telecined stream:
Top fields: 1 2 2 3 4
Bottom fields: 1 2 3 4 4
The numbers correspond to the progressive frame the fields relate to. Here, the first two frames are progressive, the 3rd and 4th are combed, and so on.
When fieldmatch is configured to run a matching from bottom (field=bottom) this is how this input stream gets transformed:
Input stream:
T 1 2 2 3 4
B 1 2 3 4 4 <-- matching reference
Matches: c c n n c
Output stream:
T 1 2 3 4 4
B 1 2 3 4 4
As a result of the field matching, we can see that some frames get duplicated. To perform a complete inverse telecine, you need to rely on a decimation filter after this operation. See for instance the decimate filter.
The same operation now matching from top fields (field=top) looks like this:
Input stream:
T 1 2 2 3 4 <-- matching reference
B 1 2 3 4 4
Matches: c c p p c
Output stream:
T 1 2 2 3 4
B 1 2 2 3 4
In these examples, we can see what p, c and n mean; basically, they refer to the frame and field of the opposite parity:
pโ matches the field of the opposite parity in the previous framecโ matches the field of the opposite parity in the current framenโ matches the field of the opposite parity in the next frame
u/b
The u and b matching are a bit special in the sense that they match from the opposite parity flag. In the following examples, we assume that we are currently matching the 2nd frame (Top:2, bottom:2). According to the match, an 'x' is placed above and below each matched fields.
With bottom matching (field=bottom):
Match: c p n b u
x x x x x
Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
x x x x x
Output frames:
2 1 2 2 2
2 2 2 1 3
With top matching (field=top):
Match: c p n b u
x x x x x
Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
x x x x x
Output frames:
2 2 2 1 2
2 1 3 2 2
Examples
- Simple IVTC of a top field first telecined stream:
fieldmatch=order=tff:combmatch=none, decimate
- Advanced IVTC, with fallback on
yadiffor still combed frames:
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
fieldorder ๐ธ
Transform the field order of the input video.
It accepts the following parameters:
orderโ the output field order. Valid values aretfffor top field first orbfffor bottom field first.
The default value is tff.
The transformation is done by shifting the picture content up or down by one line, and filling the remaining line with appropriate picture content. This method is consistent with most broadcast field order converters.
If the input video is not flagged as being interlaced, or it is already flagged as being of the required output field order, then this filter does not alter the incoming video.
It is very useful when converting to or from PAL DV material, which is bottom field first.
For example:
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
fillborders ๐ฆ
Fill borders of the input video, without changing video stream dimensions. Sometimes video can have garbage at the four edges and you may not want to crop video input to keep size multiple of some number.
This filter accepts the following options:
leftโ number of pixels to fill from left border.rightโ number of pixels to fill from right border.topโ number of pixels to fill from top border.bottomโ number of pixels to fill from bottom border.modeโ set fill mode. It accepts the following values:smearโ fill pixels using outermost pixelsmirrorโ fill pixels using mirroring (half sample symmetric)fixedโ fill pixels with constant valuereflectโ fill pixels using reflecting (whole sample symmetric)wrapโ fill pixels using wrappingfadeโ fade pixels to constant valuemarginsโ fill pixels at top and bottom with weighted averages pixels near borders
Default is smear.
colorโ set color for pixels infixedorfademode. Default is black.
Commands ๐ฌ
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value.
find_rect ๐
Find a rectangular object in the input video.
The object to search for must be specified as a gray8 image specified with the object option.
For each possible match, a score is computed. If the score reaches the specified threshold, the object is considered found.
If the input video contains multiple instances of the object, the filter will find only one of them.
When an object is found, the following metadata entries are set in the matching frame:
lavfi.rect.wโ width of objectlavfi.rect.hโ height of objectlavfi.rect.xโ x position of objectlavfi.rect.yโ y position of objectlavfi.rect.scoreโ match score of the found object
It accepts the following options:
objectโ filepath of the object image; needs to be ingray8.thresholdโ detection threshold, expressed as a decimal number in the range0-1. A threshold value of0.01means only exact matches, a threshold of0.99means almost everything matches. Default value is0.5.mipmapsโ number of mipmaps, default is3.xmin,ymin,xmax,ymaxโ specifies the rectangle in which to search.discardโ discard frames where object is not detected. Default is disabled.
Examples
- Cover a rectangular object by the supplied image of a given video using
ffmpeg:
ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
- Find the position of an object in each frame using
ffprobeand write it to a log file:
ffprobe -f lavfi movie=test.mp4,find_rect=object=object.pgm:threshold=0.3 \
-show_entries frame=pkt_pts_time:frame_tags=lavfi.rect.x,lavfi.rect.y \
-of csv -o find_rect.csv
floodfill ๐
Flood area with values of same pixel components with another values.
It accepts the following options:
xโ set pixel x coordinate.yโ set pixel y coordinate.s0โ set source #0 component value.s1โ set source #1 component value.s2โ set source #2 component value.s3โ set source #3 component value.d0โ set destination #0 component value.d1โ set destination #1 component value.d2โ set destination #2 component value.d3โ set destination #3 component value.
format ๐จ
Convert the input video to one of the specified pixel formats. Libavfilter will try to pick one that is suitable as input to the next filter.
It accepts the following parameters:
pix_fmtsโ a'|'-separated list of pixel format names, such aspix_fmts=yuv420p|monow|rgb24.color_spacesโ a'|'-separated list of color space names, such ascolor_spaces=bt709|bt470bg|bt2020nc.color_rangesโ a'|'-separated list of color range names, such ascolor_ranges=tv|pc.alpha_modesโ a'|'-separated list of color range names, such asalpha_modes=straight|premultiplied.
Examples
- Convert the input video to the
yuv420pformat:
format=pix_fmts=yuv420p
- Convert the input video to any of the formats in the list:
format=pix_fmts=yuv420p|yuv444p|yuv410p
๐ธ fps ๐ธ
Okay so bestie, this one turns your video into a constant frame rate by duplicating or dropping frames whenever it needs to. It's giving "I will make your timeline behave." โจ
It accepts these parameters:
fpsโ the output frame rate you want. It takes expressions containing these constants, and yes you can use them:source_fpsโ the input's frame ratentscโ NTSC frame rate of30000/1001palโ PAL frame rate of25.0filmโ film frame rate of24.0ntsc_filmโ NTSC-film frame rate of24000/1001
The default is 25.
start_timeโ assume the first PTS should be this value, in seconds. This lets you pad/trim at the start of the stream. By default no assumption is made about the first frame's expected PTS, so no padding or trimming happens. For example, you could set this to0to pad the beginning with duplicates of the first frame if a video stream starts after the audio stream, or to trim any frames with a negative PTS. ๐roundโ the timestamp (PTS) rounding method. Possible values:zeroโ round towards 0infโ round away from 0downโ round towards -infinityupโ round towards +infinitynearโ round to nearest
The default is near.
eof_actionโ what gets performed when reading the last frame. Possible values:roundโ use the same timestamp rounding method as used for other frames.passโ pass through the last frame if input duration has not been reached yet.
The default is round.
Alternatively you can specify the options as a flat string, like fps[:start_time[:round]].
Also go peek at the setpts filter, they're neighbors ๐ซถ
Examples
- A typical usage in order to set the fps to 25:
fps=fps=25
- Sets the fps to 24, using abbreviation and rounding method to round to nearest:
fps=fps=film:round=near
๐ฆ framepack ๐ฆ
Pack two different video streams into a stereoscopic video, setting proper metadata on supported codecs. The two views should have the same size and framerate, and processing stops when the shorter video ends โ so like, the shorter one is the vibe-setter, no cap. Pls note you can conveniently adjust view properties with the scale and fps filters. ๐
It accepts the following parameters:
formatโ the desired packing format. Supported values are:sbsโ the views are next to each other (default).tabโ the views are on top of each other.linesโ the views are packed by line.columnsโ the views are packed by column.frameseqโ the views are temporally interleaved.
Some examples:
# Convert left and right views into a frame-sequential video
ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
# Convert views into a side-by-side video with the same output resolution as the input
ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
โญ framerate โญ
Change the frame rate by interpolating new video output frames from the source frames. It's literally inventing frames, main character energy. ๐ญ
Okay this is the important part: this filter is not designed to function correctly with interlaced media. If you want to change the frame rate of interlaced media then you are required to deinterlace before this filter and re-interlace after this filter. No skipping steps, bestie.
A description of the accepted options follows.
fpsโ specify the output frames per second. This option can also be specified as a value alone. The default is50.interp_startโ specify the start of a range where the output frame will be created as a linear interpolation of two frames. The range is[0-255], the default is15.interp_endโ specify the end of a range where the output frame will be created as a linear interpolation of two frames. The range is[0-255], the default is240.sceneโ specify the level at which a scene change is detected as a value between0and100to indicate a new scene; a low value reflects a low probability for the current frame to introduce a new scene, while a higher value means the current frame is more likely to be one. The default is8.2.flagsโ specify flags influencing the filter process. Available value for flags is:scene_change_detect,scdโ enable scene change detection using the value of the optionscene. This flag is enabled by default.
๐ framestep ๐
Select one frame every N-th frame. Snip snip โ๏ธ
This filter accepts the following option:
stepโ select frame after everystepframes. Allowed values are positive integers higher than0. Default value is1.
๐ freezedetect ๐
Detect frozen video. Yes, it's watching for when your video just... stops living. ๐
This filter logs a message and sets frame metadata when it detects that the input video has no significant change in content during a specified duration. Video freeze detection calculates the mean average absolute difference of all the components of video frames and compares it to a noise floor.
The printed times and duration are expressed in seconds. The lavfi.freezedetect.freeze_start metadata key is set on the first frame whose timestamp equals or exceeds the detection duration, and it contains the timestamp of the first frame of the freeze. The lavfi.freezedetect.freeze_duration and lavfi.freezedetect.freeze_end metadata keys are set on the first frame after the freeze.
The filter accepts the following options:
noise,nโ set noise tolerance. Can be specified in dB (in casedBis appended to the specified value) or as a difference ratio between0and1. Default is-60dB, or0.001.duration,dโ set freeze duration until notification (default is2seconds).
๐ง freezeframes ๐ง
Freeze video frames. Ice ice baby ๐ง
This filter freezes video frames using frame from 2nd input.
The filter accepts the following options:
firstโ set number of first frame from which to start freeze.lastโ set number of last frame from which to end freeze.replaceโ set number of frame from 2nd input which will be used instead of replaced frames.
๐ frei0r ๐
Apply a frei0r effect to the input video. This is the "plug in your favorite effects" filter and it ate, honestly.
To enable the compilation of this filter, you need to install the frei0r header and configure FFmpeg with --enable-frei0r.
It accepts the following parameters:
filter_nameโ the name of the frei0r effect to load. If the environment variableFREI0R_PATHis defined, the frei0r effect is searched for in each of the directories specified by the colon-separated list inFREI0R_PATH. Otherwise, the standard frei0r paths are searched, in this order:HOME/.frei0r-1/lib/,/usr/local/lib/frei0r-1/,/usr/lib/frei0r-1/.filter_paramsโ a'|'-separated list of parameters to pass to the frei0r effect.
A frei0r effect parameter can be a boolean (its value is either y or n), a double, a color (specified as R/G/B, where R, G, and B are floating point numbers between 0.0 and 1.0, inclusive) or a color description as specified in the Color section in the ffmpeg-utils manual, a position (specified as X/Y, where X and Y are floating point numbers) and/or a string.
The number and types of parameters depend on the loaded effect. If an effect parameter is not specified, the default value is set.
Examples
- Apply the
distort0reffect, setting the first two double parameters:
frei0r=filter_name=distort0r:filter_params=0.5|0.01
- Apply the
colordistanceeffect, taking a color as the first parameter:
frei0r=colordistance:0.2/0.3/0.4
frei0r=colordistance:violet
frei0r=colordistance:0x112233
- Apply the
perspectiveeffect, specifying the top left and top right image positions:
frei0r=perspective:0.2/0.2|0.8/0.2
For more information, see http://frei0r.dyne.org
Commands
This filter supports the filter_params option as commands. ๐
๐ fspp ๐
Apply fast and simple postprocessing. It's a faster version of spp โ same energy, less waiting.
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-processing filter, one of them is performed once per block, not per pixel. This allows for much higher speed. Slay. ๐ฅ
The filter accepts the following options:
qualityโ set quality. This option defines the number of levels for averaging. It accepts an integer in the range4-5. Default value is4.qpโ force a constant quantization parameter. It accepts an integer in range0-63. If not set, the filter will use the QP from the video stream (if available).strengthโ set filter strength. It accepts an integer in range-15to32. Lower values mean more details but also more artifacts, while higher values make the image smoother but also blurrier. Default value is0โ PSNR optimal.use_bframe_qpโ enable the use of the QP from the B-Frames if set to1. Using this option may cause flicker since the B-Frames have often larger QP. Default is0(not enabled).
That flicker warning is real, bestie โ don't come for me if you turn it on and things get jumpy.
๐ fsync ๐
Synchronize video frames with an external mapping from a file. It's giving "match my frames to the map, exactly." ๐บ๏ธ
For each input PTS given in the map file it either drops or creates as many frames as necessary to recreate the sequence of output frames given in the map file.
This filter is useful to recreate the output frames of a framerate conversion by the fps filter, recorded into a map file using the ffmpeg option -stats_mux_pre, and do further processing to the corresponding frames e.g. quality comparison.
Each line of the map file must contain three items per input frame, the input PTS (decimal), the output PTS (decimal) and the output TIMEBASE (decimal/decimal), separated by a space. This file format corresponds to the output of -stats_mux_pre_fmt="{ptsi} {pts} {tb}".
The filter assumes the map file is sorted by increasing input PTS.
The filter accepts the following options:
file,fโ the filename of the map file to be used.
Example
# Convert a video to 25 fps and record a MAP_FILE file with the default format of this filter
ffmpeg -i INPUT -vf fps=fps=25 -stats_mux_pre MAP_FILE -stats_mux_pre_fmt "{ptsi} {pts} {tb}" OUTPUT
# Sort MAP_FILE by increasing input PTS
sort -n MAP_FILE
# Use INPUT, OUTPUT and the MAP_FILE from above to compare the corresponding frames in INPUT and OUTPUT via SSIM
ffmpeg -i INPUT -i OUTPUT -filter_complex '[0:v]fsync=file=MAP_FILE[ref];[1:v][ref]ssim' -f null -
โจ gblur โจ
Apply Gaussian blur filter. Soft focus, dreamy, iconic. ๐ธ
The filter accepts the following options:
sigmaโ set horizontal sigma, standard deviation of Gaussian blur. Default is0.5.stepsโ how many steps you want for the Gaussian approximation. Default is1.planesโ which planes get filtered. By default, all planes are filtered.sigmaVโ vertical sigma. If it's negative it just uses the same value as"sigma". Default is-1.
๐ Commands
This filter supports the same commands as options, bestie. The command takes the exact same syntax as the corresponding option.
If the expression you fed it isn't valid, it just stays at its current value. No drama. ๐
๐ geq
Apply a generic equation to each pixel. That's it, that's the filter. Math homework but make it โจaestheticโจ.
The filter accepts the following options:
lum_expr,lumโ set the luma expression.cb_expr,cbโ set the chrominance blue expression.cr_expr,crโ set the chrominance red expression.alpha_expr,aโ set the alpha expression.red_expr,rโ set the red expression.green_expr,gโ set the green expression.blue_expr,bโ set the blue expression.
The colorspace gets picked based on whatever options you specified, like it's reading the room. If you specify one of lum_expr, cb_expr, or cr_expr, the filter automatically selects a YCbCr colorspace. If you specify one of red_expr, green_expr, or blue_expr, it selects an RGB colorspace instead.
If one of the chrominance expressions isn't defined, it falls back on the other one. If no alpha expression is specified, it evaluates to opaque. And if none of the chrominance expressions are specified at all, they all just evaluate to the luma expression. Iconic teamwork honestly. ๐ซถ
The expressions can use the following variables and functions:
Nโ the sequential number of the filtered frame, starting from0.X,Yโ the coordinates of the current sample.W,Hโ the width and height of the image.SW,SHโ width and height scale depending on the currently filtered plane. It's the ratio between the corresponding luma plane's number of pixels and the current plane's ones. E.g. for YUV4:2:0 the values are"1,1"for the luma plane, and"0.5,0.5"for chroma planes.Tโ time of the current frame, expressed in seconds.p(x, y)โ return the value of the pixel at location (x,y) of the current plane.lum(x, y)โ return the value of the pixel at location (x,y) of the luma plane.cb(x, y)โ return the value of the pixel at location (x,y) of the blue-difference chroma plane. Returns0if there's no such plane.cr(x, y)โ return the value of the pixel at location (x,y) of the red-difference chroma plane. Returns0if there's no such plane.r(x, y),g(x, y),b(x, y)โ return the value of the pixel at location (x,y) of the red/green/blue component. Returns0if there's no such component.alpha(x, y)โ return the value of the pixel at location (x,y) of the alpha plane. Returns0if there's no such plane.psum(x,y),lumsum(x, y),cbsum(x,y),crsum(x,y),rsum(x,y),gsum(x,y),bsum(x,y),alphasum(x,y)โ sum of sample values in the rectangle from (0,0) to (x,y). This lets you get sums of samples within a rectangle. See the functions without thesumpostfix for the version you're prob used to.interpolationโ set one of the interpolation methods:nearest,nbilinear,b
Default is bilinear.
For functions, if x and y are outside the area, the value gets automatically clipped to the closer edge. No rage-quitting on out-of-bounds, it just snaps to the nearest edge like a good little function.
Please note that this filter can use multiple threads, in which case each slice has its own expression state. If you want only a single expression state because your expressions depend on previous state, then you should limit the number of filter threads to 1. fr fr, don't skip this one.
โจ Examples โจ
- Flip the image horizontally:
geq=p(W-X\,Y)
- Generate a bidimensional sine wave, with angle
"PI/3"and a wavelength of 100 pixels:
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
- Generate a fancy enigmatic moving light:
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
- Generate a quick emboss effect:
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
- Modify RGB components depending on pixel position:
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
- Create a radial gradient that is the same size as the input (also see the
vignettefilter):
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
๐ฆ gradfun
Fixes those banding artifacts that sometimes show up in nearly flat regions when everything gets truncated to 8-bit color depth. It interpolates the gradients that should go where the bands are, and dithers them. Basically it does damage control for bit-depth trauma ๐ญโจ.
It's designed for playback only. Do not use it prior to lossy compression, because compression tends to lose the dither and bring back the bands. That's the whole point, bestie, don't undo it.
It accepts the following parameters:
strengthโ the maximum amount by which the filter will change any one pixel. This is also the threshold for detecting nearly flat regions. Acceptable values range from.51to64; the default value is1.2. Out-of-range values get clipped to the valid range.radiusโ the neighborhood to fit the gradient to. A larger radius makes for smoother gradients, but also prevents the filter from modifying the pixels near detailed regions. Acceptable values are8-32; the default value is16. Out-of-range values get clipped to the valid range.
Alternatively, the options can be specified as a flat string: strength[:radius]
โจ Examples โจ
- Apply the filter with a
3.5strength and radius of8:
gradfun=3.5:8
- Specify radius, omitting the strength (which falls back to the default value):
gradfun=radius=8
๐ graphmonitor
Shows you various filtergraph stats. It's literally the main character of debugging.
With this filter you can debug a complete filtergraph. Especially issues with links filling up with queued frames. So when things are getting sus and backing up, this is your girl. ๐
The filter accepts the following options:
size,sโ set video output size. Default ishd720.opacity,oโ set video opacity. Default is0.9. Allowed range is from0to1.mode,mโ set output mode flags.
Available values for flags are:
fullโ no any filtering. Default.compactโ show only filters with queued frames.nozeroโ show only filters with non-zero stats.noeofโ show only filters with non-eof stat.nodisabledโ show only filters that are enabled in timeline.
flags,fโ set flags which enable which stats are shown in video.
Available values for flags are:
noneโ all flags turned off.allโ all flags turned on.queueโ display number of queued frames in each link.frame_count_inโ display number of frames taken from filter.frame_count_outโ display number of frames given out from filter.frame_count_deltaโ display delta number of frames between above two values.ptsโ display current filtered frame pts.pts_deltaโ display pts delta between current and previous frame.timeโ display current filtered frame time.time_deltaโ display time delta between current and previous frame.timebaseโ display time base for filter link.formatโ display used format for filter link.sizeโ display video size or number of audio channels in case of audio used by filter link.rateโ display video frame rate or sample rate in case of audio used by filter link.eofโ display link output status.sample_count_inโ display number of samples taken from filter.sample_count_outโ display number of samples given out from filter.sample_count_deltaโ display delta number of samples between above two values.disabledโ show the timeline filter status.
rate,rโ set upper limit for video rate of output stream. Default value is25. This guarantees that output video frame rate will not be higher than this value. No cap, it's capped. ๐
๐ธ grayworld
A color constancy filter that applies color correction based on the grayworld assumption. It's giving "the average of the world is gray" and honestly? It works.
The algorithm uses linear light, so input data should be linearized beforehand (and possibly correctly tagged). Don't skip this step, bestie, it matters.
ffmpeg -i INPUT -vf zscale=transfer=linear,grayworld,zscale=transfer=bt709,format=yuv420p OUTPUT
๐ง greyedge
A color constancy variation filter which estimates scene illumination via the grey edge algorithm and corrects the scene colors accordingly. Same energy as grayworld but it went to a different school.
See: https://staff.science.uva.nl/th.gevers/pub/GeversTIP07.pdf
The filter accepts the following options:
diffordโ the order of differentiation to be applied on the scene. Must be chosen in the range[0,2]and default value is1.minknormโ the Minkowski parameter to be used for calculating the Minkowski distance. Must be chosen in the range[0,20]and default value is1. Set to0for getting max value instead of calculating Minkowski distance.sigmaโ the standard deviation of Gaussian blur to be applied on the scene. Must be chosen in the range[0,1024.0]and default value =1.floor( sigma * break_off_sigma(3) )can't be equal to0ifdiffordis greater than0.
โจ Examples โจ
- Grey Edge:
greyedge=difford=1:minknorm=5:sigma=2
- Max Edge:
greyedge=difford=1:minknorm=0:sigma=2
๐ guided
Apply a guided filter for edge-preserving smoothing, dehazing and so on. A whole little multitool, honestly obsessed.
The filter accepts the following options:
radiusโ set the box radius in pixels. Allowed range is1to20. Default is3.epsโ set regularization parameter (with square). Allowed range is0to1. Default is0.01.modeโ set filter mode. Can be"basic"or"fast". Default is"basic".subโ set subsampling ratio for"fast"mode. Range is2to64. Default is4. No subsampling occurs in"basic"mode.guidanceโ set guidance mode. Can be"off"or"on". Default is"off". If"off", single input is required. If"on", two inputs of the same resolution and pixel format are required. The second input serves as the guidance. Like a little buddy holding your hand ๐ซถplanesโ set planes to filter. Default is first only.
๐ Commands
This filter supports the all above options as commands. Yup, all of them.
โจ Examples โจ
- Edge-preserving smoothing with guided filter:
ffmpeg -i in.png -vf guided out.png
- Dehazing, structure-transferring filtering, detail enhancement with guided filter. For the generation of guidance image, refer to paper "Guided Image Filtering". See:
http://kaiminghe.com/publications/pami12guidedfilter.pdf.
ffmpeg -i in.png -i guidance.png -filter_complex guided=guidance=on out.png
haldclut ๐
Apply a Hald CLUT to a video stream. <sparkle>โจ</sparkle>
First input is the video stream to process, and second one is the Hald CLUT. The Hald CLUT input can be a simple picture or a complete video stream.
The filter accepts the following options:
clutโ Set which CLUT video frames will be processed from second input stream, can befirstorall. Default isall.shortestโ Force termination when the shortest input terminates. Default is0.repeatlastโ Continue applying the last CLUT after the end of the stream. A value of0disable the filter after the last frame of the CLUT is reached. Default is1.
haldclut also has the same interpolation options as lut3d (both filters share the same internals).
This filter also supports the framesync options.
More information about the Hald CLUT can be found on Eskil Steenberg's website (Hald CLUT author) at http://www.quelsolaar.com/technology/clut.html.
Commands
This filter supports the interp option as commands. ๐ซถ
Workflow examples
Hald CLUT video stream
Generate an identity Hald CLUT stream altered with various effects:
ffmpeg -f lavfi -i B<haldclutsrc>=8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
Note: make sure you use a lossless codec. ๐
Then use it with haldclut to apply it on some random stream:
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
The Hald CLUT will be applied to the 10 first seconds (duration of clut.nut), then the latest picture of that CLUT stream will be applied to the remaining frames of the mandelbrot stream.
Hald CLUT with preview
A Hald CLUT is supposed to be a squared image of Level*Level*Level by Level*Level*Level pixels. For a given Hald CLUT, FFmpeg will select the biggest possible square starting at the top left of the picture. The remaining padding pixels (bottom or right) will be ignored. This area can be used to add a preview of the Hald CLUT.
Typically, the following generated Hald CLUT will be supported by the haldclut filter:
ffmpeg -f lavfi -i B<haldclutsrc>=8 -vf "
pad=iw+320 [padded_clut];
smptebars=s=320x256, split [a][b];
[padded_clut][a] overlay=W-320:h, curves=color_negative [main];
[main][b] overlay=W-320" -frames:v 1 clut.png
It contains the original and a preview of the effect of the CLUT: SMPTE color bars are displayed on the right-top, and below the same color bars processed by the color changes.
Then, the effect of this Hald CLUT can be visualized with:
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
hflip ๐ฆ
Flip the input video horizontally.
For example, to horizontally flip the input video with ffmpeg:
ffmpeg -i in.avi -vf "hflip" out.avi
histeq ๐
This filter applies a global color histogram equalization on a per-frame basis.
It can be used to correct video that has a compressed range of pixel intensities. The filter redistributes the pixel intensities to equalize their distribution across the intensity range. It may be viewed as an "automatically adjusting contrast filter". This filter is useful only for correcting degraded or poorly captured source video. fr fr
The filter accepts the following options:
strengthโ Determine the amount of equalization to be applied. As the strength is reduced, the distribution of pixel intensities more-and-more approaches that of the input frame. The value must be a float number in the range[0,1]and defaults to0.200.intensityโ Set the maximum intensity that can generated and scale the output values appropriately. The strength should be set as desired and then the intensity can be limited if needed to avoid washing-out. The value must be a float number in the range[0,1]and defaults to0.210.antibandingโ Set the antibanding level. If enabled the filter will randomly vary the luminance of output pixels by a small amount to avoid banding of the histogram. Possible values arenone,weakorstrong. It defaults tonone.
histogram โจ
Compute and draw a color distribution histogram for the input video.
The computed histogram is a representation of the color component distribution in an image.
Standard histogram displays the color components distribution in an image. Displays color graph for each color component. Shows distribution of the Y, U, V, A or R, G, B components, depending on input format, in the current frame. Below each graph a color component scale meter is shown.
The filter accepts the following options:
level_heightโ Set height of level. Default value is200. Allowed range is[50, 2048].scale_heightโ Set height of color scale. Default value is12. Allowed range is[0, 40].display_modeโ Set display mode. It accepts the following values:stackโ Per color component graphs are placed below each other.paradeโ Per color component graphs are placed side by side.overlayโ Presents information identical to that in theparade, except that the graphs representing color components are superimposed directly over one another.
Default is stack.
levels_modeโ Set mode. Can be eitherlinear, orlogarithmic. Default islinear.componentsโ Set what color components to display. Default is7.fgopacityโ Set foreground opacity. Default is0.7.bgopacityโ Set background opacity. Default is0.5.colors_modeโ Set colors mode. It accepts the following values:whiteonblackblackonwhitewhiteongrayblackongraycoloronblackcoloronwhitecolorongrayblackoncolorwhiteoncolorgrayoncolor
Default is whiteonblack.
Examples
- Calculate and draw histogram:
ffplay -i input -vf histogram
hqdn3d ๐
This is a high precision/quality 3d denoise filter. It aims to reduce image noise, producing smooth images and making still images really still. It should enhance compressibility. <sparkle>โจ</sparkle>
It accepts the following optional parameters:
luma_spatialโ A non-negative floating point number which specifies spatial luma strength. It defaults to4.0.chroma_spatialโ A non-negative floating point number which specifies spatial chroma strength. It defaults to3.0*luma_spatial/4.0.luma_tmpโ A floating point number which specifies luma temporal strength. It defaults to6.0*luma_spatial/4.0.chroma_tmpโ A floating point number which specifies chroma temporal strength. It defaults toluma_tmp*chroma_spatial/luma_spatial.
Commands
This filter supports same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value.
hwdownload ๐ซถ
Download hardware frames to system memory.
The input must be in hardware frames, and the output a non-hardware format. Not all formats will be supported on the output - it may be necessary to insert an additional format filter immediately following in the graph to get the output in a supported format.
hwmap ๐ง
Map hardware frames to system memory or to another device.
This filter has several different modes of operation; which one is used depends on the input and output formats:
- Hardware frame input, normal frame output โ Map the input frames to system memory and pass them to the output. If the original hardware frame is later required (for example, after overlaying something else on part of it), the
hwmapfilter can be used again in the next mode to retrieve it. - Normal frame input, hardware frame output โ If the input is actually a software-mapped hardware frame, then unmap it - that is, return the original hardware frame.
Otherwise, a device must be provided. Create new hardware surfaces on that device for the output, then map them back to the software format at the input and give those frames to the preceding filter. This will then act like the hwupload filter, but may be able to avoid an additional copy when the input is already in a compatible format.
- Hardware frame input and output โ A device must be supplied for the output, either directly or with the
derive_deviceoption. The input and output devices must be of different types and compatible - the exact meaning of this is system-dependent, but typically it means that they must refer to the same underlying hardware context (for example, refer to the same graphics card).
If the input frames were originally created on the output device, then unmap to retrieve the original frames.
Otherwise, map the frames to the output device - create new hardware frames on the output corresponding to the frames on the input.
The following additional parameters are accepted:
modeโ Set the frame mapping mode. Some combination of:readโ The mapped frame should be readable.writeโ The mapped frame should be writeable.overwriteโ The mapping will always overwrite the entire frame.
This may improve performance in some cases, as the original contents of the frame need not be loaded.
directโ The mapping must not involve any copying.
Indirect mappings to copies of frames are created in some cases where either direct mapping is not possible or it would have unexpected properties. Setting this flag ensures that the mapping is direct and will fail if that is not possible.
Defaults to read+write if not specified.
derive_devicetype โ Rather than using the device supplied at initialisation, instead derive a new device of type type from the device the input frames exist on.reverseโ In a hardware to hardware mapping, map in reverse - create frames in the sink and map them back to the source. This may be necessary in some cases where a mapping in one direction is required but only the opposite direction is supported by the devices being used.
โ ๏ธ Heads up bestie โ this option is dangerous. It may break the preceding filter in undefined ways if there are any additional constraints on that filter's output. Do not use it without fully understanding the implications of its use. Like, fr fr. ๐
hwupload ๐
Uploads system memory frames onto hardware surfaces. Glow-up but for your frames, no cap.
The device you're uploading to must be supplied when the filter is initialised. If you're using ffmpeg, pick the right device with the -filter_hw_device option or with the derive_device option. The input and output devices have to be of different types and compatible โ the exact meaning of that is system-dependent, but typically it means they must refer to the same underlying hardware context (for example, refer to the same graphics card). iykyk ๐ซถ
The following additional parameters are accepted:
derive_devicetype โ rather than using the device supplied at initialisation, instead derive a new device of type type from the device the input frames exist on. โจ
hwupload_cuda ๐ฆ
Uploads system memory frames to a CUDA device. Same energy, NVIDIA-flavoured.
It accepts the following optional parameters:
deviceโ the number of the CUDA device to use. ๐ฅ
hqx ๐
Applies a high-quality magnification filter designed for pixel art. This filter was originally created by Maxim Stepin โ absolute icon behavior, we stan. ๐
It accepts the following option:
nโ set the scaling dimension:2forhq2x,3forhq3xand4forhq4x. Default is3. ๐
hstack ๐
Stacks input videos horizontally. Side by side, bestie, like a group photo.
All streams must be of same pixel format and of same height. Non-negotiable.
Note that this filter is faster than using overlay and pad filter to create same output. Efficiency queen. โญ
The filter accepts the following option:
inputsโ set number of input streams. Default is2.shortestโ if set to1, force the output to terminate when the shortest input terminates. Default value is0.
hsvhold ๐
Turns a certain HSV range into gray values.
This filter measures color difference between set HSV color in options and ones measured in video stream. Depending on options, output colors can be changed to be gray or not. It's giving selective desaturation main character energy. ๐
The filter accepts the following options:
hueโ set the hue value which will be used in color difference calculation. Allowed range is from-360to360. Default value is0.satโ set the saturation value which will be used in color difference calculation. Allowed range is from-1to1. Default value is0.valโ set the value which will be used in color difference calculation. Allowed range is from-1to1. Default value is0.similarityโ set similarity percentage with the key color. Allowed range is from0to1. Default value is0.01.0.00001matches only the exact key color, while1.0matches everything. literally everything. ๐ญ
blendโ blend percentage. Allowed range is from0to1. Default value is0.0.0makes pixels either fully gray, or not gray at all.- Higher values result in more gray pixels, with a higher gray pixel the more similar the pixels color is to the key color.
hsvkey ๐ง
Turns a certain HSV range into transparency.
This filter measures color difference between set HSV color in options and ones measured in video stream. Depending on options, output colors can be changed to transparent by adding alpha channel. Yes she adds the alpha channel herself, we love a self-starter. โจ
The filter accepts the following options:
hueโ set the hue value which will be used in color difference calculation. Allowed range is from-360to360. Default value is0.satโ set the saturation value which will be used in color difference calculation. Allowed range is from-1to1. Default value is0.valโ set the value which will be used in color difference calculation. Allowed range is from-1to1. Default value is0.similarityโ set similarity percentage with the key color. Allowed range is from0to1. Default value is0.01.0.00001matches only the exact key color, while1.0matches everything.
blendโ blend percentage. Allowed range is from0to1. Default value is0.0.0makes pixels either fully transparent, or not transparent at all.- Higher values result in semi-transparent pixels, with a higher transparency the more similar the pixels color is to the key color.
hue ๐ธ
Modifies the hue and/or the saturation of the input. The classic. The moment. The blueprint.
It accepts the following parameters:
hโ specify the hue angle as a number of degrees. It accepts an expression, and defaults to"0".sโ specify the saturation in the[-10,10]range. It accepts an expression and defaults to"1".Hโ specify the hue angle as a number of radians. It accepts an expression, and defaults to"0".bโ specify the brightness in the[-10,10]range. It accepts an expression and defaults to"0".
Bestie,handHare mutually exclusive โ you can't specify both at the same time. Pick a lane ๐
The b, h, H and s option values are expressions containing the following constants:
nโ frame count of the input frame starting from0ptsโ presentation timestamp of the input frame expressed in time base unitsrโ frame rate of the input video,NANif the input frame rate is unknowntโ timestamp expressed in seconds,NANif the input timestamp is unknowntbโ time base of the input video
Examples ๐
- Set the hue to 90 degrees and the saturation to 1.0:
hue=h=90:s=1
- Same command but expressing the hue in radians:
hue=H=PI/2:s=1
- Rotate hue and make the saturation swing between 0 and 2 over a period of 1 second:
hue="H=2*PI*t: s=sin(2*PI*t)+1"
- Apply a 3 seconds saturation fade-in effect starting at 0:
hue="s=min(t/3\,1)"
The general fade-in expression can be written as:
hue="s=min(0\, max((t-START)/DURATION\, 1))"
- Apply a 3 seconds saturation fade-out effect starting at 5 seconds:
hue="s=max(0\, min(1\, (8-t)/3))"
The general fade-out expression can be written as:
hue="s=max(0\, min(1\, (START+DURATION-t)/DURATION))"
Commands ๐
This filter supports the following commands:
bshH
Modify the hue and/or the saturation and/or brightness of the input video. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. No crash, no drama, just vibes. ๐ซถ
huesaturation ๐ฆ
Applies hue-saturation-intensity adjustments to input video stream.
This filter operates in RGB colorspace. Just so you know where you are, bestie.
This filter accepts the following options:
hueโ set the hue shift in degrees to apply. Default is0. Allowed range is from-180to180.saturationโ set the saturation shift. Default is0. Allowed range is from-1to1.intensityโ set the intensity shift. Default is0. Allowed range is from-1to1.colorsโ set which primary and complementary colors are going to be adjusted. This options is set by providing one or multiple values. This can select multiple colors at once. By default all colors are selected.rโ adjust reds.yโ adjust yellows.gโ adjust greens.cโ adjust cyans.bโ adjust blues.mโ adjust magentas.aโ adjust all colors.
strengthโ set strength of filtering. Allowed range is from0to100. Default value is1.rw,gw,bwโ set weight for each RGB component. Allowed range is from0to1. By default is set to0.333,0.334,0.333. Those options are used in saturation and lightess processing.lightnessโ set preserving lightness, by default is disabled. Adjusting hues can change lightness from original RGB triplet, with this option enabled lightness is kept at same value. Protect the lightness at all costs ๐ฅ
hysteresis โญ
Grow first stream into second stream by connecting components. This makes it possible to build more robust edge masks. Lowkey the glow-up your edges have been waiting for.
This filter accepts the following options:
planesโ set which planes will be processed as bitmap, unprocessed planes will be copied from first stream. By default value0xf, all planes will be processed.thresholdโ set threshold which is used in filtering. If pixel component value is higher than this value filter algorithm for connecting components is activated. By default value is0.
The hysteresis filter also supports the framesync options. ๐
iccdetect ๐ง
Detect the colorspace from an embedded ICC profile (if present), and update the frame's tags accordingly. Detective mode: activated. ๐ต๏ธโโ๏ธ
This filter accepts the following options:
forceโ if true, the frame's existing colorspace tags will always be overridden by values detected from an ICC profile. Otherwise, they will only be assigned if they containunknown. Enabled by default.
iccgen ๐
Generate ICC profiles and attach them to frames. She's making them from scratch, we love an artisan. โจ
This filter accepts the following options:
color_primariescolor_trc
Configure the colorspace that the ICC profile will be generated for. The default value of "auto" infers the value from the input frame's metadata, defaulting to BT.709/sRGB as appropriate.
See the setparams filter for a list of possible values, but note that "unknown" are not valid values for this filter. ๐
โโ๏ธ
forceโ if true, an ICC profile will be generated even if it would overwrite an already existing ICC profile. Disabled by default.
identity ๐ญ
Obtains the identity score between two input videos. Basically a beauty contest, but for frames, and it's measuring how similar they are.
This filter takes two input videos.
Both input videos must have the same resolution and pixel format for this filter to work correctly. Also it assumes that both inputs have the same number of frames, which are compared one by one. No mixing and matching, bestie.
The obtained per component, average, min and max identity score is printed through the logging system.
The filter stores the calculated identity scores of each frame in frame metadata. Data girlie ๐
This filter also supports the framesync options.
In the below example the input file main.mpg being processed is compared with the reference file ref.mpg.
ffmpeg -i main.mpg -i ref.mpg -lavfi identity -f null -
idet ๐
Detects video interlacing type.
This filter tries to detect if the input frames are interlaced, progressive, top or bottom field first. It will also try to detect fields that are repeated between adjacent frames (a sign of telecine). She's nosy and we love that for her. ๐ธ
Single frame detection considers only immediately adjacent frames when classifying each frame. Multiple frame detection incorporates the classification history of previous frames. The way that it remembers the pastโฆ iconic.
The filter will log these metadata values:
single.current_frameโ detected type of current frame using single-frame detection. One of:`tff`(top field first),`bff`(bottom field first),`progressive`, or`undetermined`. The last one is the "idk she's giving mysterious" option. ๐single.tffโ cumulative count of frames the filter clocked as top field first using single-frame detection ๐multiple.tffโ same thing but via multiple-frame detection, so the count of top-field-first frames the multi-frame way โจsingle.bffโ cumulative count of frames detected as bottom field first, single-frame detection ๐ฆmultiple.current_frameโ the vibe check on the current frame, determined with multiple-frame detection. It's one of:tff(top field first),bff(bottom field first),progressive, orundetermined๐multiple.bffโ cumulative count of bottom-field-first frames found via multiple-frame detection ๐ธsingle.progressiveโ cumulative count of frames detected as progressive, single-frame detection ๐ซถmultiple.progressiveโ cumulative count of frames detected as progressive, multiple-frame detection ๐single.undeterminedโ cumulative count of frames that single-frame detection just could NOT classify (mystery frames, we stan) ๐ญmultiple.undeterminedโ same energy, but the frames multiple-frame detection couldn't classify ๐repeated.current_frameโ which field in the current frame got repeated from the last one. One ofneither,top, orbottom๐repeated.neitherโ cumulative count of frames with zero repeated fields โจrepeated.topโ cumulative count of frames where the top field is a repeat of the previous frame's top field ๐repeated.bottomโ cumulative count of frames where the bottom field is repeated from the previous frame's bottom field โญ
The filter accepts the following options:
intl_thresโ sets the interlacing threshold ๐๏ธprog_thresโ sets the progressive threshold ๐๏ธrep_thresโ the threshold for repeated field detection ๐half_lifeโ number of frames after which a given frame's contribution to the statistics gets halved (like, it only contributes0.5to its classification now). The default of0means all frames seen are given full weight of1.0forever, no decay, main character energy periodt ๐analyze_interlaced_flagโ when this isn't0,idetuses the specified number of frames to figure out if the interlaced flag is actually accurate. It will not count undetermined frames. If the flag turns out accurate, it's used with no further computations; if it turns out inaccurate, it gets cleared with no further computations. This is the whole point: it lets you dropidetin as a low-computation way to clean up the interlaced flag ๐ง
โจ Examples โจ
Wanna inspect the field order of the first 360 frames in a video, in verbose detail? Say less:
ffmpeg -i INPUT -filter:v idet,metadata=mode=print -frames:v 360 -an -f null -
The idet filter adds analysis metadata to each frame, which then gets discarded (rip metadata, you served your purpose ๐). At the end, the filter also prints a final report with all the statistics. Slay.
๐ il
Deinterleave or interleave fields. Iconic.
This filter lets you process interlaced image fields without deinterlacing them. Deinterleaving splits the input frame into 2 fields (the so-called half pictures). Odd lines get moved to the top half of the output image, even lines to the bottom half. Then you can process (filter) them independently and re-interleave them after ๐
The filter accepts the following options:
luma_mode,lchroma_mode,calpha_mode,a
Available values for luma_mode, chroma_mode and alpha_mode are:
noneโ do nothing. Literally nothing. A vibe.deinterleave,dโ deinterleave fields, placing one above the other.interleave,iโ interleave fields. Reverses the effect of deinterleaving.
Default value is none.
luma_swap,lschroma_swap,csalpha_swap,as
Swap the luma/chroma/alpha fields. Exchanges even & odd lines. Default value is 0 ๐ฆ
Commands
This filter supports the all above options as commands ๐
๐ซ inflate
Apply the inflate effect to the video.
This filter replaces the pixel with the local (3x3) average, but only counting values higher than the pixel. So it puffs up the bright bits, basically โจ
It accepts the following options:
threshold0threshold1threshold2threshold3
These limit the maximum change for each plane. Default is 65535. If 0, that plane remains unchanged, untouched, unbothered ๐ซถ
Commands
This filter supports the all above options as commands.
๐ interlace, interlace_vulkan
Simple interlacing filter from progressive contents. This interleaves upper (or lower) lines from odd frames with lower (or upper) lines from even frames โ halving the frame rate and preserving image height. The way that math works out is genuinely so satisfying ngl ๐ญ
Original Original New Frame
Frame 'j' Frame 'j+1' (tff)
========== =========== ==================
Line 0 --------------------> Frame 'j' Line 0
Line 1 Line 1 ----> Frame 'j+1' Line 1
Line 2 ---------------------> Frame 'j' Line 2
Line 3 Line 3 ----> Frame 'j+1' Line 3
... ... ...
New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
It accepts the following optional parameters:
scanโ determines whether the interlaced frame is taken from the even (tffโ default) or odd (bff) lines of the progressive frame ๐lowpassโ vertical lowpass filter to avoid twitter interlacing and reduce moire patterns ๐0,offโ disable vertical lowpass filter1,linearโ enable linear filter (default)2,complexโ enable complex filter. This reduces twitter and moire slightly less, but better retains detail and the subjective impression of sharpness. Trade-offs, bestie ๐
๐ฅ kerndeint
Deinterlace input video by applying Donald Graft's adaptive kernel deinterling (that's the spelling in the original, we don't gatekeep ๐ซถ). Works on the interlaced parts of a video to produce progressive frames.
The description of the accepted parameters follows.
threshโ set the threshold which affects the filter's tolerance when determining if a pixel line must be processed. It must be an integer in the range [0,255] and defaults to10. A value of0will result in applying the process on every pixel. Every single one. No cap ๐mapโ Paint pixels exceeding the threshold value to white if set to1. Default is0.orderโ set the fields order. Swap fields if set to1, leave fields alone if0. Default is0.sharpโ enable additional sharpening if set to1. Default is0.twowayโ enable twoway sharpening if set to1. Default is0.
Examples
- Apply default values:
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
- Enable additional sharpening:
kerndeint=sharp=1
- Paint processed pixels in white:
kerndeint=map=1
๐ kirsch
Apply the kirsch operator to the input video stream. Edge detection but make it fashion โจ
The filter accepts the following option:
planesโ set which planes will be processed; unprocessed planes get copied. By default the value is0xf, so all planes are processed ๐scaleโ set the value which gets multiplied with the filtered result ๐ขdeltaโ set the value which gets added to the filtered result โ
Commands
This filter supports the all above options as commands.
๐ lagfun
Slowly update darker pixels.
This filter makes short flashes of light appear longer. It's giving afterimage, it's giving light trails, we're obsessed ๐ฆ
This filter accepts the following options:
decayโ set the factor for decaying. Default is.95. Allowed range is from0to1๐planesโ set which planes to filter. Default is all. Allowed range is from0to15.
Commands
This filter supports the all above options as commands.
๐ง lenscorrection
Correct radial lens distortion. Glow-up for your wide angle footage, lowkey.
This filter can be used to correct radial distortion as can result from the use of wide angle lenses, and thereby re-rectify the image. To find the right parameters one can use tools available for example as part of opencv or simply trial-and-error. To use opencv use the calibration sample (under samples/cpp) from the opencv sources and extract the k1 and k2 coefficients from the resulting matrix ๐
Note that effectively the same filter is available in the open-source tools Krita and Digikam from the KDE project. Snaps for them ๐
In contrast to the vignette filter, which can also be used to compensate lens errors, this filter corrects the distortion of the image, whereas vignette corrects the brightness distribution. So you may want to use both filters together in certain cases, though you'll have to take care of ordering, i.e. whether vignetting should be applied before or after lens correction. Order matters, bestie, always ๐
Options
The filter accepts the following options:
cxโ relative x-coordinate of the focal point of the image, and thereby the center of the distortion. This value has a range [0,1] and is expressed as fractions of the image width. Default is0.5๐ฏcyโ relative y-coordinate of the focal point of the image, and thereby the center of the distortion. This value has a range [0,1] and is expressed as fractions of the image height. Default is0.5๐ฏk1โ coefficient of the quadratic correction term. This value has a range [-1,1].0means no correction. Default is0.k2โ coefficient of the double quadratic correction term. This value has a range [-1,1].0means no correction. Default is0.iโ set the interpolation type. Can benearestorbilinear. Default isnearest.fcโ specify the color of the unmapped pixels. For the syntax of this option, check theColorsection in theffmpeg-utilsmanual. Default color isblack@0๐ค
The formula that generates the correction is:
r_src = r_tgt * (1 + k1 * (r_tgt / r_0)^2 + k2 * (r_tgt / r_0)^4)
where r_0 is halve of the image diagonal and r_src and r_tgt are the distances from the focal point in the source and target images, respectively. Math ate, honestly ๐งฎ
Commands
This filter supports the all above options as commands.
๐ธ lensfun
Apply lens correction via the lensfun library (http://lensfun.sourceforge.net/).
The lensfun filter requires the camera make, camera model, and lens model to apply the lens correction. The filter will load the lensfun database and query it to find the corresponding camera and lens entries in the database. As long as these entries can be found with the given options, the filter can perform corrections on frames. Note that incomplete strings will result in the filter choosing the best match with the given options, and the filter will output the chosen camera and lens models (logged with level info). You must provide the make, camera model, and lens model as they are required โ non-negotiable, bestie ๐
Okay bestie, before we even get into the options: if you leave out one or both of make and model, the filter will just yeet the entire list of available makes and models into the log at level "INFO" โ first column is the make, second column is the model, no cap. Want the lens list instead? Set any values you like for make and model and leave out lens_model, and the full list of lenses gets dropped into the log at level "INFO". Literally iconic. One giant heads-up though: the ffmpeg tool will exit after the list is printed, so don't be surprised when it dips out on you ๐
The filter accepts the following options:
makeโ the make of the camera (for example,"Canon"). This option is required, no skipping it ๐ซถmodelโ the model of the camera (for example,"Canon EOS 100D"). Also required, periodt.lens_modelโ the model of the lens (for example,"Canon EF-S 18-55mm f/3.5-5.6 IS STM"). Required too, all three of them, the whole squad.db_pathโ the full path to the lens database folder. If you don't set it, the filter tries to load the database from the install path it was built with at library-compile time. Default is unset.modeโ the type of correction to apply. The valid values are:vignettingโ fixes lens vignetting โจgeometryโ fixes lens geometry. This is the default, iykyk.subpixelโ fixes chromatic aberrations.vig_geoโ fixes lens vignetting and lens geometry together.vig_subpixelโ fixes lens vignetting and chromatic aberrations.distortionโ fixes both lens geometry and chromatic aberrations.allโ enables all possible corrections. all of them. the whole buffet ๐ฅ
focal_lengthโ the focal length of the image/video (the zoom; expected to be constant for video). Like, an 18--55mm lens has a focal length range of[18--55], so pick a value inside that range when you're using that lens. Default18.apertureโ the aperture of the image/video (again, expected constant for video). Note that aperture is only used for vignetting correction. Default3.5.focus_distanceโ the focus distance of the image/video (expected constant for video). Note that focus distance is only used for vignetting, and it only slightly affects the vignetting correction process. If you don't know it, just leave it at the default value, which is1000.scaleโ the scale factor applied after the transformation. After correction the video isn't necessarily rectangular anymore, so this parameter controls how much of the resulting image is visible. A value of0means a value gets chosen automatically so there's little or no unmapped area in the output image.1.0means no additional scaling at all. Lower values may show more of the corrected image, higher values may avoid unmapped areas in the output. Balance, bestie ๐งtarget_geometryโ the target geometry of the output image/video. Valid values:rectilinear(default)fisheyepanoramicequirectangularfisheye_orthographicfisheye_stereographicfisheye_equisolidfisheye_thoby
reverseโ apply the reverse of image correction, meaning instead of correcting distortion, you apply it. Going backwards, we love a plot twist ๐interpolationโ the type of interpolation used when correcting distortion. Valid values:nearestlinear(default)lanczos
โจ Examples โจ
- Apply lens correction with make
"Canon", camera model"Canon EOS 100D", and lens model"Canon EF-S 18-55mm f/3.5-5.6 IS STM", with a focal length of"18"and aperture of"8.0":
ffmpeg -i input.mov -vf lensfun=make=Canon:model="Canon EOS 100D":lens_model="Canon EF-S 18-55mm f/3.5-5.6 IS STM":focal_length=18:aperture=8 -c:v h264 -b:v 8000k output.mov
- Same thing as before, but only for the first 5 seconds of video:
ffmpeg -i input.mov -vf lensfun=make=Canon:model="Canon EOS 100D":lens_model="Canon EF-S 18-55mm f/3.5-5.6 IS STM":focal_length=18:aperture=8:enable='lte(t\,5)' -c:v h264 -b:v 8000k output.mov
๐ lcevc
Low Complexity Enhancement Video Codec filter, built on liblcevc_dec (<https://github.com/v-novaltd/LCEVCdec>). That's the whole description, she's short and mysterious, main character energy fr.
๐ฆ libplacebo
Flexible GPU-accelerated processing filter, built on libplacebo (<https://code.videolan.org/videolan/libplacebo>). GPU go brrr.
โจ Options โจ
The options for this filter are split into the following sections:
๐ Output mode ๐
These options control the overall output mode. By default, libplacebo tries to preserve the source colorimetry and size as best as it can โ but it will apply any embedded film grain, dolby vision metadata, or anamorphic SAR present in the source frames. Like, it's doing its best, okay?
inputsโ set the number of inputs. Alongside theidxvariable, this lets you place/blend multiple inputs inside the output frame. Effectively, it gives you functionality similar tohstack,overlay, etc. Slay ๐w,hโ set the output video dimension expression. Default values areiwandih. Allows for the same expressions as thescalefilter, bestie.crop_x,crop_yโ set the input crop x/y expressions. Default values are(iw-cw)/2and(ih-ch)/2.crop_w,crop_hโ set the input crop width/height expressions. Default values areiwandih.pos_x,pos_yโ set the output placement x/y expressions. Default values are(ow-pw)/2and(oh-ph)/2.pos_w,pos_hโ set the output placement width/height expressions. Default values areowandoh.rotateโ rotate the input frame clockwise by the specified angle. The angles are:0,36090180270
fpsโ set the output frame rate. This can be rational, e.g.60000/1001. If you set it to the special string"none"(which is the default), input timestamps get passed through to the output unmodified instead. Otherwise, the input video frames are interpolated as necessary to rescale the video to the specified target framerate, in a manner determined by theframe_mixeroption.formatโ set the output format override. If unset (the default), frames are output in the same format as the respective input frames. Otherwise, format conversion is performed.force_original_aspect_ratio,force_divisible_byโ these work exactly the same as the identicalscalefilter options. Note thatforce_divisible_byalso works withfit_sense=constraint๐reset_sarโ if enabled, output frames always have a pixel aspect ratio of1:1. If disabled (the default), any aspect ratio mismatches โ including those coming from, like, anamorphic video sources โ get forwarded to the output pixel aspect ratio.normalize_sarโ likereset_sar, except instead of stretching the video content to fill the new output aspect ratio, the content is padded or cropped as necessary. Mutually exclusive withfit_mode. Disabled by default.pad_crop_ratioโ specifies a ratio (between0.0and1.0) between padding and cropping, for when the input aspect ratio doesn't match the output aspect ratio andnormalize_saris in effect. The default of0.0always pads the content with black borders, while1.0always crops off parts of the content. Intermediate values are possible and give you a mix of the two approaches. Yes queen, compromise ๐fit_modeโ specify the content fit strategy from a list of predefined modes. It determines how the input image is placed inside the destination crop rectangle (as defined bypos_x/yandpos_w/h). The names and their implementations are taken from the CSS'object-fit'property. Note that this option is mutually exclusive withnormalize_sar. Defaults to"fill". Valid values:fillโ stretch the input to the output rectangle, ignoring aspect ratio mismatches. Note that unlessreset_saris also enabled, the output will still have the correct pixel aspect ratio tagged.containโ scale the input to fit inside the output, preserving aspect ratio by padding. Equivalent tonormalize_sarwithpad_crop_ratioset to0.0.coverโ scale the input to fill the output, preserving aspect ratio by cropping. Equivalent tonormalize_sarwithpad_crop_ratioset to1.0.none,placeโ don't scale the input. It gets placed inside the output rectangle at its natural size, which may result in additional padding or cropping.scale_downโ scale the input down as much as needed to fit inside the output. Equivalent to either"contain"or"none", depending on whether the input is larger than the output or not.
fit_senseโ whenfit_modeis in use, this option controls how the fit strategy is applied against the specified output resolution. Mutually exclusive withforce_original_aspect_ratio. Valid values:targetโ the computed output resolution is taken as the exact size of the output frame. This is the default behavior.constraintโ the computed output resolution is a size reference against which the fit mode is applied, enlarging or decreasing the true frame size as needed to fit the content.
fillcolorโ set the color used to fill the output area not covered by the output image, for example as a result ofnormalize_sar. For the general syntax of this option, check the"Color"section in the ffmpeg-utils manual. Defaults to"black@0".corner_roundingโ render frames with rounded corners ๐ The value, given as a float ranging from0.0to1.0, indicates the relative degree of rounding, from fully square to fully circular. In other words, it gives the radius divided by half the smaller side length. Defaults to0.0.lutโ specifies a custom LUT (in Adobe.cubeformat) to apply to the colors as part of color conversion. The exact interpretation depends on the value oflut_type.lut_typeโ controls the interpretation of color values fed to and from the LUT specified aslut. Valid values:autoโ chooses the interpretation of the LUT automatically from tagged metadata, and otherwise falls back tonative. (Default)nativeโ applied to raw image contents in its native RGB colorspace (non-linear light), before conversion to the output color space.normalizedโ applied to the normalized RGB image contents, in linear light, before conversion to the output color space.
conversionโ this one fully replaces the conversion from the image color space to the output color space. Like, whole thing, swapped out. And if a LUT is present it has the highest priority โ it overrides any ICC profiles, and it also overrides the options related to tone mapping and output colorimetry (color_primaries,color_trc). It's giving main character energy, it wins every argument ๐extra_optsโ pass extra libplacebo internal configuration options through here. You write them as a list ofkey=valuepairs separated by:. The example below shows how to configure a custom filter kernel ("EWA LanczosSharp") and then use it to double the input image resolution:
-vf "libplacebo=w=iw*2:h=ih*2:extra_opts='upscaler=custom\:upscaler_preset=ewa_lanczos\:upscaler_blur=0.9812505644269356'"
shader_cacheโ file path of a cache directory that libplacebo will use to store and load cached shader objects. Important vibes: this cache is not cleaned up automatically, bestie. Nobody's coming to tidy it. Also, if the path does not end in a directory separator, the generated filenames will be effectively prefixed by the last path component. And all the directories must already exist โ it will not make them for you.
-vf "libplacebo=shader_cache=/tmp/pl-shader-"
colorspacecolor_primariescolor_trcrangechroma_locationโ configure the colorspace that output frames will be delivered in. The default value of"auto"outputs frames in the same format as the input frames, which literally means no change at all. For any other value, conversion will be performed.
See the setparams filter for a list of possible values ๐
alpha_modeโ choose the desired output alpha mode, for when the output format has an alpha channel. See thesetparamsfilter for a list of possible values.apply_filmgrainโ apply film grain (like AV1 or H.274) if it's present in the source frames, and strip it from the output. Enabled by default โจapply_dolbyvisionโ apply Dolby Vision RPU metadata if it's present in the source frames, and strip it from the output. Also enabled by default. Heads up though: Dolby Vision will always output BT.2020+PQ, overriding the usual input frame metadata. Those get picked as the values of"auto"for the respective frame output options too.
So, on top of the expression constants documented for the scale filter, the crop_w, crop_h, crop_x, crop_y, pos_w, pos_h, pos_x and pos_y options can also contain these constants:
in_idx,idxโ the (0-based) numeric index of the currently active input stream.crop_w,cwโ the computed values ofcrop_wandcrop_h.crop_h,chโ the computed values ofcrop_wandcrop_h.pos_w,pwโ the computed values ofpos_wandpos_h.pos_h,phโ the computed values ofpos_wandpos_h.in_t,tโ the input frame timestamp, in seconds.NANif the input timestamp is unknown.out_t,otโ the input frame timestamp, in seconds.NANif the input timestamp is unknown.nโ the input frame number, starting with 0.
๐ Scaling ๐
The options in this section control how libplacebo performs upscaling and (if necessary) downscaling. And okay, super important detail so listen up ๐ซถ โ libplacebo will always internally operate on 4:4:4 content, so any sub-sampled chroma formats like "yuv420p" will necessarily be upsampled and downsampled as part of the rendering process. Which means scaling might be in effect even if the source and destination resolution are the same ๐ญ that's just how it is.
upscalerdownscalerโ configure the filter kernel used for upscaling and downscaling. The respective defaults are"spline36"and"mitchell". For a full list of possible values, pass"help"to these options. The most important values are:noneโ forces the use of built-in GPU texture sampling (typically bilinear). Extremely fast but poor quality, especially when downscaling. Fast and ugly, we've all been there ๐bilinearโ bilinear interpolation. Can generally be done for free on GPUs, except when doing so would lead to aliasing. Fast and low quality.nearestโ nearest-neighbour interpolation. Sharp but highly aliasing.oversampleโ an algorithm that looks visually similar to nearest-neighbour interpolation but tries to preserve pixel aspect ratio. Good for pixel art, since it results in minimal distortion of the artistic appearance ๐จ iconic for the pixel artists fr frlanczosโ standard sinc-sinc interpolation kernel.spline36โ cubic spline approximation of lanczos. No difference in performance, but has very slightly less ringing.ewa_lanczosโ elliptically weighted average version of lanczos, based on a jinc-jinc kernel. This is also popularly referred to as just"Jinc scaling". Slow but very high quality. Queen behaviour ๐gaussianโ gaussian kernel. Has certain ideal mathematical properties, but subjectively very blurry. Math says yes, eyes say no.mitchellโ cubic BC spline with parameters recommended by Mitchell and Netravali. Very little ringing.
frame_mixerโ controls the kernel used for mixing frames temporally. The default value is"none", which disables frame mixing. For a full list of possible values, pass"help"to this option. The most important values are:noneโ disables frame mixing, giving a result equivalent to"nearest neighbour"semantics.oversampleโ oversamples the input video to create a"Smooth Motion"-type effect: if an output frame would exactly fall on the transition between two video frames, it is blended according to the relative overlap. This is the recommended option whenever preserving the original subjective appearance is desired.mitchell_clampโ a larger filter kernel that smoothly interpolates multiple frames in a manner designed to eliminate ringing and other artefacts as much as possible. This is the recommended option wherever maximum visual smoothness is desired.linearโ linear blend/fade between frames. Especially useful for constructing e.g. slideshows ๐ผ๏ธ
antiringingโ enables anti-ringing (for non-EWA filters) โ nay, slays ringing. The value (between0.0and1.0) configures the strength of the anti-ringing algorithm. May increase aliasing if set too high, so don't get greedy. Disabled by default.sigmoidโ enable sigmoidal compression during upscaling. Reduces ringing slightly. Enabled by default.
๐ฆ Deinterlacing ๐ฆ
Deinterlacing is automatically supported when frames are tagged as interlaced, however โ and this is the sneaky part โ frames are not deinterlaced unless a deinterlacing algorithm is chosen. So tagging alone gets you nothing, bestie.
deinterlaceโ the deinterlacing algorithm to use.weaveโ no deinterlacing, weave fields together into a single frame. This is the default.bobโ naive bob deinterlacing, simply repeat each field line twice.yadifโ yet another deinterlacing filter. See theyadiffilter for more details.bwdifโ bob weaver deinterlacing filter. See thebwdiffilter for more details.
skip_spatial_checkโ skip the spatial deinterlacing check when using"yadif"deinterlacing.send_fieldsโ output a frame for each field, rather than for each frame. Note that this will always double the tagged output frame rate, even if the input does not contain any interlaced frames. Disabled by default.
๐ Debanding ๐
Libplacebo comes with a built-in debanding filter that is genuinely good at counteracting many common sources of banding and blocking. Turning this on is highly recommended whenever quality is desired โ like, why wouldn't you ๐ฅ
debandโ enable the (fast) debanding algorithm. Disabled by default.deband_iterationsโ number of deband iterations of the debanding algorithm. Each iteration is performed with progressively increased radius (and diminished threshold). Recommended values are in the range1to4. Defaults to1.deband_thresholdโ debanding filter strength. Higher numbers lead to more aggressive debanding. Defaults to4.0.deband_radiusโ debanding filter radius. A higher radius is better for slow gradients, while a lower radius is better for steep gradients. Defaults to16.0.deband_grainโ amount of extra output grain to add. Helps hide imperfections โ a little texture never hurt anybody. Defaults to6.0.
๐ Color adjustment ๐
A collection of subjective color controls. Not very rigorous, so the exact effect will vary somewhat depending on the input primaries and colorspace. Basically it's vibes-based color grading, and that's fine.
brightnessโ brightness boost, between-1.0and1.0. Defaults to0.0.contrastโ contrast gain, between0.0and16.0. Defaults to1.0.saturationโ saturation gain, between0.0and16.0. Defaults to1.0.hueโ hue shift in radians, between-3.14and3.14. Defaults to0.0. This will rotate the UV subvector, defaulting to BT.709 coefficients for RGB inputs.gammaโ gamma adjustment, between0.0and16.0. Defaults to1.0.temperatureโ color temperature adjustment. Lower values make the output warmer/redder, down to1667, while higher values make the output cooler/bluer, up to25000. Defaults to6500(neutral white).conesโ cone model to use for color blindness simulation. Accepts any combination of"l","m"and"s". Here are some examples:mโ deuteranomaly / deuteranopia (affecting 3%-4% of the population)lโ protanomaly / protanopia (affecting 1%-2% of the population)l+mโ monochromacy (very rare)l+m+sโ achromatopsy (complete loss of daytime vision, extremely rare)
cone-strengthโ gain factor for the cones specified by"cones", between0.0and10.0. A value of1.0results in no change to color vision. A value of0.0(the default) simulates complete loss of those cones. Values above1.0result in exaggerating the differences between cones, which may help compensate for reduced color vision.
โญ Peak detection โญ
To help deal with sources that only have static HDR10 metadata (or no tagging whatsoever, we've all met those files ๐ญ), libplacebo uses its own internal frame analysis compute shader to analyze source frames and adapt the tone mapping function in realtime. If this is too slow, or if you need exactly reproducible frame-perfect results, it's recommended to turn this feature off. Trade-offs, babe.
peak_detectโ enable HDR peak detection. Ignores static MaxCLL/MaxFALL values in favor of dynamic detection from the input. Note that the detected values do not get written back to the output frames โ they merely guide the internal tone mapping process. Enabled by default.smoothing_periodโ the peak-detection smoothing period, and it lives between0.0and1000.0bestie. Higher values mean peak detection gets all chill and less responsive to changes in the input. Defaults to20.0. ๐scene_threshold_low,scene_threshold_highโ the lower and upper thresholds for scene change detection, expressed on a logarithmic scale between0.0and100.0. They default to1.0and3.0respectively. Set either one to a negative value and this whole feature just โจ turns off โจ โ no cap.percentileโ which percentile of the frame brightness histogram gets used as the source peak for tone-mapping. Defaults to99.995, which is a fairly conservative value (she's careful, she's sensible). Setting this to100.0disables frame histogram measurement entirely and instead uses the true peak brightness for tone-mapping. ๐
๐ Tone mapping ๐
The options in this section control how libplacebo does tone-mapping and gamut-mapping when it's dealing with mismatches between wide-gamut or HDR content. Lowkey, libplacebo relies on accurate source tagging and mastering display gamut information to produce the best results โ so like, tag your stuff properly, iykyk.
gamut_modeโ how to handle out-of-gamut colors that can occur as a result of colorimetric gamut mapping. The values are:clipโ do nothing, just clip out-of-range colors to the RGB volume. Low quality but extremely fast, it's giving "we have no time and we're fine with that".perceptualโ perceptually soft-clip colors to the gamut volume. This is the default. ๐relativeโ relative colorimetric hard-clip. Similar toperceptualbut without the soft knee.saturationโ saturation mapping, maps primaries directly to primaries in RGB space. Not recommended except for artificial computer graphics where a bright, saturated display is what you want.absoluteโ absolute colorimetric hard-clip. Performs no adjustment of the white point.desaturateโ hard-desaturates out-of-gamut colors towards white while preserving the luminance. Has a tendency to distort the visual appearance of bright objects ๐ซฃ.darkenโ linearly reduces content brightness to preserve saturated details, followed by clipping the remaining out-of-gamut colors.warnโ highlight out-of-gamut pixels (by inverting/marking them). It's the "hey bestie look here" mode ๐.linearโ linearly reduces chromaticity of the entire image to make it fit within the target color volume. Be careful when using this on BT.2020 sources without proper mastering metadata, because doing so will lead to excessive desaturation. That's a real warning, not a vibe.
tonemappingโ the tone-mapping algorithm to use. Available values:autoโ automatic selection based on internal heuristics. This is the default. ๐งclipโ performs no tone-mapping, just clips out-of-range colors. Retains perfect color accuracy for in-range colors but completely destroys out-of-range information. Does not perform any black point adaptation. Not configurable.st2094-40โ EETF from SMPTE ST 2094-40 Annex B, which applies the Bezier curves from HDR10+ dynamic metadata based on Bezier curves to perform tone-mapping. The OOTF used is adjusted based on the ratio between the targeted and actual display peak luminances.st2094-10โ EETF from SMPTE ST 2094-10 Annex B.2, which takes into account the input signal average luminance in addition to the maximum/minimum. The configurable contrast parameter influences the slope of the linear output segment, defaulting to1.0for no increase/decrease in contrast. Note that this does not currently include the subjective gain/offset/gamma controls defined in Annex B.3 โ so like, don't go looking for them, they're not here ๐.bt.2390โ EETF from the ITU-R Report BT.2390, a hermite spline roll-off with linear segment. The knee point offset is configurable. Note that this parameter defaults to1.0, rather than the value of0.5from the ITU-R spec.bt.2446aโ EETF from ITU-R Report BT.2446, method A. Designed for well-mastered HDR sources. Can be used for both forward and inverse tone mapping. Not configurable.splineโ simple spline consisting of two polynomials, joined by a single pivot point. The parameter gives the pivot point (in PQ space), defaulting to0.30. Can be used for both forward and inverse tone mapping.reinhardโ simple non-linear, global tone mapping algorithm. The parameter specifies the local contrast coefficient at the display peak. Essentially, a parameter of0.5implies that the reference white will be about half as bright as when clipping. Defaults to0.5, which results in the simplest formulation of this function.mobiusโ generalization of thereinhardtone mapping algorithm to support an additional linear slope near black. The tone mapping parameter indicates the trade-off between the linear section and the non-linear section. Essentially, for a given parameter x, every color value below x will be mapped linearly, while higher values get non-linearly tone-mapped. Values near1.0make this curve behave likeclip, while values near0.0make this curve behave likereinhard. The default value is0.3, which provides a good balance between colorimetric accuracy and preserving out-of-gamut details. She's balanced, she's iconic ๐.hableโ piece-wise, filmic tone-mapping algorithm developed by John Hable for use in Uncharted 2, inspired by a similar tone-mapping algorithm used by Kodak. Popularized by its use in video games with HDR rendering. Preserves both dark and bright details very well, but comes with the drawback of changing the average brightness quite significantly. This is sort of similar toreinhardwith parameter0.24.gammaโ fits a gamma (power) function to transfer between the source and target color spaces, effectively resulting in a perceptual hard-knee joining two roughly linear sections. This preserves details at all scales fairly accurately but can result in an image with a muted or dull appearance. The parameter is used as the cutoff point, defaulting to0.5.linearโ linearly stretches the input range to the output range, in PQ space. This will preserve all details accurately but results in a significantly different average brightness. Can be used for inverse tone-mapping in addition to regular tone-mapping. The parameter can be used as an additional linear gain coefficient (defaulting to1.0).
tonemapping_paramโ for tunable tone mapping functions, this parameter can be used to fine-tune the curve behavior. Refer to the documentation oftonemapping. The default value of0.0is replaced by the curve's preferred default setting.inverse_tonemappingโ if enabled, this filter will also attempt stretching SDR signals to fill HDR output color volumes. Disabled by default.tonemapping_lut_sizeโ size of the tone-mapping LUT, between2and1024. Defaults to256. Note that this figure is squared when combined withpeak_detectโ so like, do the math bestie, it grows fast ๐.contrast_recoveryโ contrast recovery strength. If set to a value above0.0, the source image will be divided into high-frequency and low-frequency components, and a portion of the high-frequency image is added back onto the tone-mapped output. May cause excessive ringing artifacts for some HDR sources, but can improve the subjective sharpness and detail left over in the image after tone-mapping. Defaults to0.30.contrast_smoothnessโ contrast recovery lowpass kernel size. Defaults to3.5. Increasing or decreasing this will affect the visual appearance substantially. Has no effect whencontrast_recoveryis disabled. Fr fr, zero effect.
๐ฆ Dithering ๐ฆ
By default, libplacebo will dither whenever necessary, which includes rendering to any integer format below 16-bit precision. It's recommended to always leave this on, since not doing so may result in visible banding in the output, even if the debanding filter is enabled. If maximum performance is needed, use ordered_fixed instead of disabling dithering. Leave it on, bestie, she's doing important work ๐
ditheringโ the dithering method to use. Accepts the following values:noneโ disables dithering completely. May result in visible banding ๐ญ.blueโ dither with pseudo-blue noise. This is the default. ๐orderedโ tunable ordered dither pattern.ordered_fixedโ faster ordered dither with a fixed size of6. Texture-less.whiteโ dither with white noise. Texture-less.
dither_lut_sizeโ dither LUT size, as log base2 between1and8. Defaults to6, corresponding to a LUT size of64x64.dither_temporalโ enables temporal dithering. Disabled by default.
โจ Custom shaders โจ
libplacebo supports a number of custom shaders based on the mpv .hook GLSL syntax. A collection of such shaders can be found here: <https://github.com/mpv-player/mpv/wiki/User-Scripts#user-shaders>
A full description of the mpv shader format is beyond the scope of this section, but a summary can be found here: <https://mpv.io/manual/master/#options-glsl-shader>
custom_shader_pathโ specifies a path to a custom shader file to load at runtime.custom_shader_binโ specifies a complete custom shader as a raw string.
๐ Debugging / performance ๐
All of the options in this section default off. They may be of assistance when attempting to squeeze the maximum performance at the cost of quality โ it's giving "speed over beauty" and honestly, sometimes that's the move.
skip_aaโ disable anti-aliasing when downscaling.disable_linearโ disable linear light scaling.disable_builtinโ disable built-in GPU sampling (forces LUT).disable_fbosโ forcibly disable FBOs, resulting in loss of almost all functionality, but offering the maximum possible speed. Like yeah, it's fast, but at what cost ๐ญ
๐ Commands ๐
This filter supports almost all of the above options as commands. Slay.
๐ธ Examples ๐ธ
- Tone-map input to standard gamut BT.709 output:
libplacebo=colorspace=bt709:color_primaries=bt709:color_trc=bt709:range=tv
- Rescale input to fit into standard 1080p, with high quality scaling:
libplacebo=w=1920:h=1080:force_original_aspect_ratio=decrease:normalize_sar=true:upscaler=ewa_lanczos:downscaler=ewa_lanczos
- Interpolate low FPS / VFR input to smoothed constant 60 fps output:
libplacebo=fps=60:frame_mixer=mitchell_clamp
- Turn your input into a bog-standard sRGB JPEG โ like, give it the whole yuv420p / bt470bg / bt709 / iec61966-2-1 / pc treatment:
libplacebo=format=yuv420p:colorspace=bt470bg:color_primaries=bt709:color_trc=iec61966-2-1:range=pc
- Wanna deband like you actually mean it? crank those settings, bestie:
libplacebo=deband=true:deband_iterations=3:deband_radius=8:deband_threshold=6
- Run this filter on the CPU โ this is for systems with Mesa installed, and yeah you gotta turn off the most expensive options or it'll be tragic:
ffmpeg ... -init_hw_device vulkan:llvmpipe ... -vf libplacebo=upscaler=none:downscaler=none:peak_detect=false
- Suppress that CPU-based AV1/H.274 film grain application in the decoder and let this filter handle it instead. But real talk: this is only a gain if the frames are already chillin' on the GPU, or if you're using libplacebo for other stuff anyway โ otherwise the VRAM roundtrip will more than offset any speedup you were hoping for. ๐
ffmpeg -export_side_data +film_grain ... -vf libplacebo=apply_filmgrain=true
- Interop with VAAPI hwdec so you don't have to round-trip through RAM (literally the worst commute):
ffmpeg -init_hw_device vulkan -hwaccel vaapi -hwaccel_output_format vaapi ... -vf libplacebo
๐ libvmaf
Okay so this one calculates the VMAF (Video Multi-Method Assessment Fusion) score for a reference/distorted pair of input videos. Fancy quality math, we love to see it. โจ
Heads up on the order: the first input is the distorted video, and the second input is the reference video. Don't flip 'em, iykyk.
The VMAF score you get is printed through the logging system.
It needs Netflix's vmaf library (libvmaf) as a pre-requisite. Once you've installed the library you can enable it using: ./configure --enable-libvmaf.
The filter has the following options:
modelโ a|delimited list of vmaf models. Each model can be configured with a number of parameters. Default value:version=vmaf_v0.6.1featureโ a|delimited list of features. Each feature can be configured with a number of parameters.log_pathโ set the file path to be used to store log files.log_fmtโ set the format of the log file (xml,json,csv, orsub).poolโ set the pool method to be used for computing vmaf. Options aremin,harmonic_meanormean(default).n_threadsโ set number of threads to be used when initializing libvmaf. Default value:0, no threads.n_subsampleโ set frame subsampling interval to be used.
This filter also supports the framesync options.
Examples
- In the examples below, a distorted video
distorted.mpgis compared with a reference filereference.mpg. - Basic usage โ the lil starter pack:
ffmpeg -i distorted.mpg -i reference.mpg -lavfi libvmaf=log_path=output.xml -f null -
- Example with multiple models โ more models, more opinions:
ffmpeg -i distorted.mpg -i reference.mpg -lavfi libvmaf='model=version=vmaf_v0.6.1\\:name=vmaf|version=vmaf_v0.6.1neg\\:name=vmaf_neg' -f null -
- Example with multiple additional features โ collector era:
ffmpeg -i distorted.mpg -i reference.mpg -lavfi libvmaf='feature=name=psnr|name=ciede' -f null -
- Example with options and different containers โ yes the second file is
.mkv, that's the whole point, look at the filtergraph:
ffmpeg -i distorted.mpg -i reference.mkv -lavfi "[0:v]settb=AVTB,setpts=PTS-STARTPTS[main];[1:v]settb=AVTB,setpts=PTS-STARTPTS[ref];[main][ref]libvmaf=log_fmt=json:log_path=output.json" -f null -
๐ฆ libvmaf_cuda
This is the CUDA variant of the libvmaf filter. It only accepts CUDA frames โ no mixing, no matching, no exceptions. ๐
It requires Netflix's vmaf library (libvmaf) as a pre-requisite. After installing the library it can be enabled using: ./configure --enable-nonfree --enable-ffnvcodec --enable-libvmaf.
Examples
- Basic usage showing CUVID hardware decoding and CUDA scaling with
scale_cudaโ the whole glow-up pipeline:
ffmpeg \
-hwaccel cuda -hwaccel_output_format cuda -codec:v av1_cuvid -i dis.obu \
-hwaccel cuda -hwaccel_output_format cuda -codec:v av1_cuvid -i ref.obu \
-filter_complex "
[0:v]scale_cuda=format=yuv420p[dis]; \
[1:v]scale_cuda=format=yuv420p[ref]; \
[dis][ref]libvmaf_cuda=log_fmt=json:log_path=output.json
" \
-f null -
๐ limitdiff
Apply a limited difference filter using the second and optionally third video stream. It's giving "compare and choose", honestly.
The filter accepts the following options:
thresholdโ set the threshold to use when allowing certain differences between video streams. Any absolute difference value lower or exact than this threshold will pick pixel components from the first video stream.elasticityโ set the elasticity of soft thresholding when processing video streams. This value multiplied with the first one sets the second threshold. Any absolute difference value greater or exact than the second threshold will pick pixel components from the second video stream. For values between those two thresholds, linear interpolation between the first and second video stream will be used.referenceโ enable the reference (third) video stream processing. By default it's disabled. If set, this video stream will be used for calculating absolute difference with the first video stream.planesโ specify which planes will be processed. Defaults to all available.
Commands
This filter supports all of the above options as commands except the option reference. (Not everything gets to be a command, and that's okay.)
โจ limiter
Limits the pixel component values to the specified range [min, max]. Boundaries, but make it pixels. ๐
The filter accepts the following options:
minโ lower bound. Defaults to the lowest allowed value for the input.maxโ upper bound. Defaults to the highest allowed value for the input.planesโ specify which planes will be processed. Defaults to all available.
Commands
This filter supports all of the above options as commands.
๐ loop
Loop video frames. Round and round and round we go.
The filter accepts the following options:
loopโ set the number of loops. Setting this value to-1will result in infinite loops. Default is0.sizeโ set maximal size in number of frames. Default is0.startโ set first frame of loop. Default is0.timeโ set the time of loop start in seconds. Only used if the option namedstartis set to-1.
Examples
- Loop the single first frame infinitely โ the iconic eternal vibe:
loop=loop=-1:size=1:start=0
- Loop the single first frame 10 times โ a manageable amount of obsession:
loop=loop=10:size=1:start=0
- Loop the first 10 frames 5 times โ now we're getting somewhere:
loop=loop=5:size=10:start=0
๐ lut1d
Apply a 1D LUT to an input video. Slap a whole lookup table on it. ๐
The filter accepts the following options:
fileโ set the 1D LUT file name.
Currently supported formats:
cubeโ Iridascspโ cineSpace
interpโ select interpolation mode.
Available values are:
nearestโ use values from the nearest defined point.linearโ interpolate values using the linear interpolation.cosineโ interpolate values using the cosine interpolation.cubicโ interpolate values using the cubic interpolation.splineโ interpolate values using the spline interpolation.
Commands
This filter supports all of the above options as commands. ๐ซ
๐ง lut3d
Apply a 3D LUT to an input video. The 3D one. It's giving depth, literally.
The filter accepts the following options:
fileโ set the 3D LUT file name.
Currently supported formats:
3dlโ AfterEffectscubeโ Iridasdatโ DaVincim3dโ Pandoracspโ cineSpace
interpโ select interpolation mode.
Available values are:
nearestโ use values from the nearest defined point.trilinearโ interpolate values using the 8 points defining a cube.tetrahedralโ interpolate values using a tetrahedron.pyramidโ interpolate values using a pyramid.prismโ interpolate values using a prism.
Commands
This filter supports the interp option as commands. (Just the one, bestie โ know your limits.)
๐ธ lumakey
Turn certain luma values into transparency. Luma-based keying, hence the name, we're so clever. ๐
The filter accepts the following options:
thresholdโ set the luma which will be used as base for transparency. Default value is0.toleranceโ set the range of luma values to be keyed out. Default value is0.01.softnessโ set the range of softness. Default value is0. Use this to control the gradual transition from zero to full transparency.
Commands
This filter supports the same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. (No crash, no drama โ it just stays put.)
๐ lut, lutrgb, lutyuv
Compute a look-up table for binding each pixel component input value to an output value, and apply it to the input video. Very "each one, teach one" but for pixels.
lutyuv applies a lookup table to a YUV input video, lutrgb to an RGB input video.
These filters accept the following parameters:
c0โ set first pixel component expressionc1โ set second pixel component expressionc2โ set third pixel component expressionc3โ set fourth pixel component expression, corresponds to the alpha componentrโ set red component expressiongโ set green component expressionbโ set blue component expressionaโ alpha component expressionyโ set Y/luma component expressionuโ set U/Cb component expressionvโ set V/Cr component expression
Each of them specifies the expression to use for computing the lookup table for the corresponding pixel component values.
The exact component associated to each of the c* options depends on the format in input. Format-dependent, so read the room (the room being your pixel format).
The lut filter requires either YUV or RGB pixel formats in input, lutrgb requires RGB pixel formats in input, and lutyuv requires YUV. Do not come for lutrgb with YUV frames, it will not be cute.
The expressions can contain the following constants and functions:
w,hโ the input width and height.valโ the input value for the pixel component.clipvalโ the input value, clipped to theminval-maxvalrange.maxvalโ the maximum value for the pixel component.minvalโ the minimum value for the pixel component.negvalโ the negated value for the pixel component value, clipped to theminval-maxvalrange; it corresponds to the expressionmaxval-clipval+minval.clip(val)โ the computed value in val, clipped to theminval-maxvalrange.gammaval(gamma)โ the computed gamma correction value of the pixel component value, clipped to theminval-maxvalrange. It corresponds to the expressionpow((clipval-minval)/(maxval-minval)\,gamma)*(maxval-minval)+minval
All expressions default to clipval.
Commands
This filter supports the same commands as options.
Examples
- Negate input video:
lutrgb="r=maxval+minval-val:g=maxval+minval-val:b=maxval+minval-val"
lutyuv="y=maxval+minval-val:u=maxval+minval-val:v=maxval+minval-val"
Which is literally, one hundred percent, the exact same thing as:
lutrgb="r=negval:g=negval:b=negval"
lutyuv="y=negval:u=negval:v=negval"
- Negate luma โ just the luma, bestie:
lutyuv=y=negval
- Remove chroma components, turning the video into a graytone image โ bye bye color ๐:
lutyuv="u=128:v=128"
- Apply a luma burning effect โ ๐ฅ:
lutyuv="y=2*val"
- Remove green and blue components โ red era only:
lutrgb="g=0:b=0"
- Set a constant alpha channel value on input:
format=rgba,lutrgb=a="maxval-minval/2"
- Correct luma gamma by a factor of 0.5:
lutyuv=y=gammaval(0.5)
- Discard least significant bits of luma โ she's letting go of the little details:
lutyuv=y='bitand(val, 128+64+32)'
- Technicolor like effect โ vintage movie moment โจ:
lutyuv=u='(val-maxval/2)*2+maxval/2':v='(val-maxval/2)*2+maxval/2'
lut2, tlut2
Okay so lut2 takes two input streams and gives you one output stream. Two in, one out, that's the whole vibe ๐ซถ
And tlut2 โ the time lut2 โ takes two consecutive frames from a single stream instead. Same energy, different source.
This filter accepts the following parameters:
c0โ set first pixel component expressionc1โ set second pixel component expressionc2โ set third pixel component expressionc3โ set fourth pixel component expression, and yeah this one corresponds to the alpha componentdโ set output bit depth, and heads up, it's only available for thelut2filter. Default is0, which means the bit depth is automatically picked from the first input format. autopilot mode โจ
Also, lut2 supports the framesync options too, iykyk.
Each one of those specifies the expression to use for computing the lookup table for the corresponding pixel component values. Literally what it says on the tin.
The exact component associated with each of the c* options depends on the format in the inputs โ so check your format, bestie ๐
The expressions can contain the following constants:
w,hโ the input width and height.xโ the first input value for the pixel component.yโ the second input value for the pixel component.bdxโ the first input video bit depth.bdyโ the second input video bit depth.
All expressions default to x.
Commands
This filter supports all of the above options as commands โ except option d. Not d. Never d. ๐ซ
Examples
- Highlight differences between two RGB video streams:
lut2='ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,0,pow(2,bdx)-1)'
- Highlight differences between two YUV video streams:
lut2='ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,pow(2,bdx-1),pow(2,bdx)-1):ifnot(x-y,pow(2,bdx-1),pow(2,bdx)-1)'
- Show max difference between two video streams:
lut2='if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1))):if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1))):if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1)))'
maskedclamp
Clamp the first input stream with the second input and third input stream. So that's three streams in the mix, bestie ๐
It returns the value of the first stream, forced to be between second input stream minus undershoot and third input stream plus overshoot.
This filter accepts the following options:
undershootโ default value is0.overshootโ default value is0.planesโ set which planes will be processed as bitmap; unprocessed planes will be copied from the first stream. Default value is0xf, which means all planes get processed. the full set, no skips โจ
Commands
This filter supports all of the above options as commands.
maskedmax
Merge the second and third input stream into the output stream, using the absolute differences between the second input stream and the first input stream, and the absolute difference between the third input stream and the first input stream.
The picked value will come from the second input stream if the second absolute difference is greater than the first one โ otherwise it comes from the third input stream. winner takes it ๐
This filter accepts the following options:
planesโ set which planes will be processed as bitmap; unprocessed planes will be copied from the first stream. Default value is0xf, all planes processed.
Commands
This filter supports all of the above options as commands.
maskedmerge
Merge the first input stream with the second input stream, using per-pixel weights in the third input stream. Third stream's the bossy one here, lowkey ๐
A value of 0 in the third stream pixel component means the pixel component from the first stream comes back unchanged. Maximum value (eg. 255 for 8-bit videos) means the pixel component from the second stream comes back unchanged. Intermediate values define the amount of merging between both input stream's pixel components. It's a whole sliding scale, gorgeous.
This filter accepts the following options:
planesโ set which planes will be processed as bitmap; unprocessed planes will be copied from the first stream. Default value is0xf, all planes.
Commands
This filter supports all of the above options as commands.
maskedmin
Merge the second and third input stream into the output stream, using the absolute differences between the second input stream and the first input stream, and the absolute difference between the third input stream and the first input stream.
The picked value comes from the second input stream if the second absolute difference is less than the first one โ otherwise from the third input stream. Same as maskedmax but the other direction, twin flames fr fr ๐
This filter accepts the following options:
planesโ set which planes will be processed as bitmap; unprocessed planes will be copied from the first stream. Default value is0xf, all planes.
Commands
This filter supports all of the above options as commands.
maskedthreshold
Pick pixels by comparing the absolute difference of two video streams against a fixed threshold. Very demure, very threshold ๐
If the absolute difference between the pixel component of the first and second video stream is equal to or lower than the user-supplied threshold, then the pixel component from the first video stream is picked โ otherwise the pixel component from the second video stream is picked.
This filter accepts the following options:
thresholdโ set the threshold used when picking pixels from the absolute difference from two input video streams.planesโ set which planes will be processed as bitmap; unprocessed planes will be copied from the second stream (yes, second, not first โ careful bestie). Default value is0xf, all planes.modeโ set the mode of filter operation. Can beabsordiff. Default isabs.
Commands
This filter supports all of the above options as commands.
maskfun
Create a mask from the input video. Honestly iconic.
For example, it's useful for creating motion masks after the tblend filter. You're welcome ๐ซถ
This filter accepts the following options:
lowโ set low threshold. Any pixel component lower than or exactly equal to this value will be set to0.highโ set high threshold. Any pixel component higher than this value will be set to the max value allowed for the current pixel format.planesโ set planes to filter; by default all available planes are filtered.fillโ fill all frame pixels with this value.sumโ set max average pixel value for the frame. If the sum of all pixel components is higher than this average, the output frame will be completely filled with the value set by thefilloption. Typically useful for scene changes when used in combination with thetblendfilter. chef's kiss scenario detection ๐ฅ
Commands
This filter supports all of the above options as commands.
mcdeint
Apply motion-compensation deinterlacing. Fancy stuff ๐
It needs one field per frame as input, and must therefore be used together with yadif=1/3 or equivalent. Don't forget that part, it literally won't work right ๐ญ
This filter accepts the following options:
modeโ set the deinterlacing mode.
It accepts one of the following values:
fastmediumslowโ use iterative motion estimationextra_slowโ likeslow, but use multiple reference frames.
Default value is fast.
parityโ set the picture field parity assumed for the input video. It must be one of the following values:0,tffโ assume top field first1,bffโ assume bottom field first
Default value is bff.
qpโ set the per-block quantization parameter (QP) used by the internal encoder.
Higher values should result in a smoother motion vector field, but less optimal individual vectors. Default value is 1.
median
Pick the median pixel from a certain rectangle defined by radius. Very "middle child" of it ๐ธ
This filter accepts the following options:
radiusโ set horizontal radius size. Default value is1. Allowed range is an integer from1to127.planesโ set which planes to process. Default is15, which is all available planes.radiusVโ set vertical radius size. Default value is0. Allowed range is an integer from0to127. If it's0, the value will be picked from the horizontalradiusoption. inherit the vibe โจpercentileโ set median percentile. Default value is0.5. A default value of0.5will always pick median values, while0picks minimum values, and1picks maximum values. choose your fighter.
Commands
This filter supports the same commands as options. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it's kept at its current value. no crash, just vibes ๐คท
mergeplanes
Merge color channel components from several video streams. Mixing and matching, we love to see it ๐
The filter accepts up to 4 input streams, and merges the selected input planes to the output video.
This filter accepts the following options:
mappingโ set input to output plane mapping. Default is0.
The mapping is specified as a bitmap. It should be specified as a hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. Aa describes the mapping for the first plane of the output stream. A sets the number of the input stream to use (from 0 to 3), and a sets the plane number of the corresponding input to use (from 0 to 3). The rest of the mappings are similar: Bb describes the mapping for the output stream's second plane, Cc describes the mapping for the output stream's third plane, and Dd describes the mapping for the output stream's fourth plane. hex-coded destiny, honestly ๐
formatโ set output pixel format. Default isyuva444p.map0s,map1s,map2s,map3sโ set input to output stream mapping for output Nth plane. Default is0.map0p,map1p,map2p,map3pโ set input to output plane mapping for output Nth plane. Default is0.
Examples
- Merge three gray video streams of same width and height into a single video stream:
[a0][a1][a2]mergeplanes=0x001020:yuv444p
- Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
[a0][a1]mergeplanes=0x00010210:yuva444p
- Swap Y and A plane in yuva444p stream:
format=yuva444p,mergeplanes=0x03010200:yuva444pโ swap the U and V planes in ayuv420pstream:
format=yuv420p,mergeplanes=0x000201:yuv420p
format=rgb24,mergeplanes=0x000102:yuv444pโ cast anrgb24clip toyuv444p:
format=rgb24,mergeplanes=0x000102:yuv444p
mestimate ๐ฏ
Okay so this one estimates motion vectors using block matching algorithms and exports them. Where do they go? Into frame side data, bestie โ so other filters can pick them up and do their thing. It's giving "behind the scenes hero" energy ngl.
This filter accepts the following options:
methodโ pick your motion estimation method. Accepted values are:esaโ Exhaustive search algorithm.tssโ Three step search algorithm.tdlsโ Two dimensional logarithmic search algorithm.ntssโ New three step search algorithm.fssโ Four step search algorithm.dsโ Diamond search algorithm.hexbsโ Hexagon-based search algorithm.epzsโ Enhanced predictive zonal search algorithm.umhโ Uneven multi-hexagon search algorithm.- Default value is
esa. ๐
mb_sizeโ Macroblock size. Default16.search_paramโ Search parameter. Default7.
mestimate_d3d12 ๐
Bestie. This is the GPU version and it's iconic. It estimates and exports motion vectors using D3D12 hardware-accelerated motion estimation, tapping into the GPU hardware motion estimation capabilities available in DirectX 12 Video APIs โ so you get significant performance improvements over the software-based mestimate filter. Speed? Slayed.
Motion vectors are stored in frame side data to be used by other filters, just like its software sibling.
Heads up: this filter requires the input to be in d3d12 hardware pixel format. Also, it uses quarter-pixel precision for motion vector estimation. Don't forget or it will simply not work, no cap. ๐
This filter accepts the following options:
mb_sizeโ Macroblock size. Only8and16are supported. Default16.
Examples
Estimate motion vectors using D3D12 hardware acceleration with 16x16 blocks, and visualize them:
ffmpeg -hwaccel d3d12va -hwaccel_output_format d3d12 -i input.mp4 \
-vf mestimate_d3d12=mb_size=16,hwdownload,format=nv12,codecview=mv=pf \
-c:v libx264 -preset fast -b:v 5M output.mp4
midequalizer โ๏ธ
Apply the Midway Image Equalization effect using two video streams. What is that, you ask? It adjusts a pair of images to have the same histogram, while maintaining their dynamics as much as possible. Genuinely useful for stuff like matching exposures from a pair of stereo cameras โ the way that just works. โจ
This filter has two inputs and one output, which must be of same pixel format, but may be of different sizes. The output of filter is first input adjusted with midway histogram of both inputs.
This filter accepts the following option:
planesโ Set which planes to process. Default is15, which is all available planes.
minterpolate ๐
Convert the video to specified frame rate using motion interpolation. Smooth motion? We love to see it.
This filter accepts the following options:
fpsโ Specify the output frame rate. This can be rational e.g."60000/1001". Frames are dropped if fps is lower than source fps. Default60.mi_modeโ Motion interpolation mode. Following values are accepted:dupโ Duplicate previous or next frame for interpolating new ones.blendโ Blend source frames. Interpolated frame is mean of previous and next frames.mciโ Motion compensated interpolation. Following options are effective when this mode is selected:mc_modeโ Motion compensation mode. Following values are accepted:obmcโ Overlapped block motion compensation.aobmcโ Adaptive overlapped block motion compensation. Window weighting coefficients are controlled adaptively according to the reliabilities of the neighboring motion vectors to reduce oversmoothing.- Default mode is
obmc.
me_modeโ Motion estimation mode. Following values are accepted:bidirโ Bidirectional motion estimation. Motion vectors are estimated for each source frame in both forward and backward directions.bilatโ Bilateral motion estimation. Motion vectors are estimated directly for interpolated frame.- Default mode is
bilat.
meโ The algorithm to be used for motion estimation. Following values are accepted:esaโ Exhaustive search algorithm.tssโ Three step search algorithm.tdlsโ Two dimensional logarithmic search algorithm.ntssโ New three step search algorithm.fssโ Four step search algorithm.dsโ Diamond search algorithm.hexbsโ Hexagon-based search algorithm.epzsโ Enhanced predictive zonal search algorithm.umhโ Uneven multi-hexagon search algorithm.- Default algorithm is
epzs.
mb_sizeโ Macroblock size. Default16.search_paramโ Motion estimation search parameter. Default32.vsbmcโ Enable variable-size block motion compensation. Motion estimation is applied with smaller block sizes at object boundaries in order to make them less blurry. Default is0(disabled).
scdโ Scene change detection method. Scene change leads motion vectors to be in random direction. Scene change detection replace interpolated frames by duplicate ones. May not be needed for other modes. Following values are accepted:noneโ Disable scene change detection.fdiffโ Frame difference. Corresponding pixel values are compared and if it satisfiesscd_thresholdscene change is detected.- Default method is
fdiff.
scd_thresholdโ Scene change detection threshold. Default is10..
mix ๐ง
Mix several video input streams into one video stream. A whole little blend session, honestly.
A description of the accepted options follows.
inputsโ The number of inputs. If unspecified, it defaults to2.weightsโ Specify weight of each input video stream as sequence. Each weight is separated by space. If number of weights is smaller than number of frames last specified weight will be used for all remaining unset weights.scaleโ Specify scale, if it is set it will be multiplied with sum of each weight multiplied with pixel values to give final destination pixel value. By default scale is auto scaled to sum of weights.planesโ Set which planes to filter. Default is all. Allowed range is from0to15.durationโ Specify how end of stream is determined.longestโ The duration of the longest input. (default)shortestโ The duration of the shortest input.firstโ The duration of the first input.
Commands
This filter supports the following commands:
weightsscaleplanes
Syntax is same as option with same name. ๐ซถ
monochrome ๐ค
Convert video to gray using custom color filter. Moody. Artistic. Very main character.
A description of the accepted options follows.
cbโ Set the chroma blue spot. Allowed range is from-1to1. Default value is0.crโ Set the chroma red spot. Allowed range is from-1to1. Default value is0.sizeโ Set the color filter size. Allowed range is from.1to10. Default value is1.highโ Set the highlights strength. Allowed range is from0to1. Default value is0.
Commands
This filter supports the all above options as commands.
morpho ๐ฆ
This filter allows to apply main morphological grayscale transforms, erode and dilate with arbitrary structures set in second input stream.
Unlike naive implementation and much slower performance in erosion and dilation filters, when speed is critical morpho filter should be used instead. Like, if you care about speed, this is the one. Periodt.
A description of accepted options follows,
modeโ Set morphological transform to apply, can be:erodedilateopenclosegradienttophatblackhat
Default is erode.
planesโ Set planes to filter, by default all planes except alpha are filtered.structureโ Set which structure video frames will be processed from second input stream, can befirstorall. Default isall.
The morpho filter also supports the framesync options.
Commands
This filter supports same commands as options.
mpdecimate โ๏ธ
Drop frames that do not differ greatly from the previous frame in order to reduce frame rate. Basically "if this frame is a copy of the last one, why are we keeping it" energy.
The main use of this filter is for very-low-bitrate encoding (e.g. streaming over dialup modem), but it could in theory be used for fixing movies that were inverse-telecined incorrectly.
A description of the accepted options follows.
maxโ Set the maximum number of consecutive frames which can be dropped (if positive), or the minimum interval between dropped frames (if negative). If the value is0, the frame is dropped disregarding the number of previous sequentially dropped frames.
Default value is 0.
keepโ Set the maximum number of consecutive similar frames to ignore before to start dropping them. If the value is0, the frame is dropped disregarding the number of previous sequentially similar frames.
Default value is 0.
hi,lo,fracโ Set the dropping threshold values.
Values for hi and lo are for 8x8 pixel blocks and represent actual pixel value differences, so a threshold of 64 corresponds to 1 unit of difference for each pixel, or the same spread out differently over the block.
A frame is a candidate for dropping if no 8x8 blocks differ by more than a threshold of hi, and if no more than frac blocks (1 meaning the whole image) differ by more than a threshold of lo.
Default value for hi is 64*12, default value for lo is 64*5, and default value for frac is 0.33.
msad ๐
Obtain the MSAD (Mean Sum of Absolute Differences) between two input videos. A little comparison moment, we love a measurement.
This filter takes two input videos.
Both input videos must have the same resolution and pixel format for this filter to work correctly. Also it assumes that both inputs have the same number of frames, which are compared one by one. So yeah, match them up first or the math gets weird. ๐
The obtained per component, average, min and max MSAD is printed through the logging system.
The filter stores the calculated MSAD of each frame in frame metadata.
This filter also supports the framesync options.
okay so check it โ in this example, the input file main.mpg thatโs being processed gets compared with the reference file ref.mpg. ๐ซถ
ffmpeg -i main.mpg -i ref.mpg -lavfi msad -f null -
multiply ๐ฅ
Multiply the pixel values of the first video stream with the pixel values of the second video stream. Itโs giving math but make it video. โจ
The filter accepts the following options:
scaleโ set the scale applied to the second video stream. By default is1. Allowed range is from0to9. ๐๏ธoffsetโ set the offset applied to the second video stream. By default is0.5. Allowed range is from-1to1. ๐๏ธplanesโ specify planes from the input video stream that will be processed. By default all planes are processed. ๐๏ธ
Commands ๐ฌ
This filter supports same commands as options. ๐
negate ๐
Negate (invert) the input video. Literally flipping the vibes. ๐ญ
It accepts the following option:
componentsโ set components to negate.
Available values for components are:
yuvargb
negate_alphaโ with value1, it negates the alpha component, if present. Default value is0. ๐ซฅ
Commands ๐ฌ
This filter supports same commands as options. ๐
nlmeans ๐งผ
Denoise frames using the Non-Local Means algorithm. Your videoโs skin routine but for pixels. ๐
Each pixel is adjusted by looking for other pixels with similar contexts. This context similarity is defined by comparing their surrounding patches of size pxp. Patches are searched in an area of rxr around the pixel. ๐
Note that the research area defines centers for patches, which means some patches will be made of pixels outside that research area. ๐
The filter accepts the following options.
sโ set denoising strength. Default is1.0. Must be in range[1.0, 30.0]. ๐ชpโ set patch size. Default is7. Must be odd number in range[0, 99]. ๐งฉpcโ same aspbut for chroma planes. The default value is0and means automatic. ๐rโ set research size. Default is15. Must be odd number in range[0, 99]. ๐rcโ same asrbut for chroma planes. The default value is0and means automatic. ๐จ
nnedi ๐ง
Deinterlace video using neural network edge directed interpolation. Big brain energy. ๐ค
This filter accepts the following options:
weightsโ mandatory option, without the binary file the filter can not work. Currently the file can be found here:https://github.com/dubhater/vapoursynth-nnedi3/blob/master/src/nnedi3_weights.bin. โ ๏ธdeintโ set which frames to deinterlace, by default it is"all". Can be"all"or"interlaced". ๐ฌfieldโ set mode of operation.
Can be one of the following:
afโ use frame flags, both fields.aโ use frame flags, single field.tโ use top field only.bโ use bottom field only.tfโ use both fields, top first.bfโ use both fields, bottom first.
planesโ set which planes to process, by default filter process all frames. ๐ผ๏ธnsizeโ set size of local neighborhood around each pixel, used by the predictor neural network.
Can be one of the following:
s8x6s16x6s32x6s48x6s8x4s16x4s32x4
nnsโ set the number of neurons in predictor neural network. Can be one of the following:n16n32n64n128n256
qualโ controls the number of different neural network predictions that are blended together to compute the final output value. Can be"fast", default or"slow". โกetypeโ set which set of weights to use in the predictor. Can be one of the following:a,absโ weights trained to minimize absolute error.s,mseโ weights trained to minimize squared error.
pscrnโ controls whether or not the prescreener neural network is used to decide which pixels should be processed by the predictor neural network and which can be handled by simple cubic interpolation. The prescreener is trained to know whether cubic interpolation will be sufficient for a pixel or whether it should be predicted by the predictor nn. The computational complexity of the prescreener nn is much less than that of the predictor nn. Since most pixels can be handled by cubic interpolation, using the prescreener generally results in much faster processing. The prescreener is pretty accurate, so the difference between using it and not using it is almost always unnoticeable.
Can be one of the following:
noneoriginalnewnew2new3
Default is "new".
Commands ๐ฌ
This filter supports same commands as options, excluding the weights option. ๐ซ
noformat ๐ซ
Force libavfilter not to use any of the specified pixel formats for the input to the next filter. Itโs giving โnot those pixels, bestieโ. ๐
It accepts the following parameters:
pix_fmtsโ a'|'-separated list of pixel format names, such aspix_fmts=yuv420p|monow|rgb24". ๐
Examples โจ
- Force libavfilter to use a format different from
yuv420pfor the input to thevflipfilter:
noformat=pix_fmts=yuv420p,vflip
- Convert the input video to any of the formats not contained in the list:
noformat=yuv420p|yuv444p|yuv410p
noise ๐
Add noise on the video input frame. Chaos, but aesthetic. ๐ช๏ธ
The filter accepts the following options:
all_seed,c0_seed,c1_seed,c2_seed,c3_seedโ set noise seed for a specific pixel component, or all pixel components in case ofall_seed. Default value is123457. ๐ฒall_strength,alls,c0_strength,c0s,c1_strength,c1s,c2_strength,c2s,c3_strength,c3sโ set noise strength for a specific pixel component, or all pixel components in caseall_strength. Default value is0. Allowed range is[0, 100]. ๐ฅall_flags,allf,c0_flags,c0f,c1_flags,c1f,c2_flags,c2f,c3_flags,c3fโ set pixel component flags, or set flags for all components ifall_flags.
Available values for component flags are:
aโ averaged temporal noise (smoother).pโ mix random noise with a (semi)regular pattern.tโ temporal noise (noise pattern changes between frames).uโ uniform noise (gaussian otherwise).
Examples โจ
Add temporal and uniform noise to input video:
noise=alls=20:allf=t+u
normalize ๐
Normalize RGB video (aka histogram stretching, contrast stretching). See: https://en.wikipedia.org/wiki/Normalization_(image_processing). Itโs giving glow-up for your contrast. โจ
For each channel of each frame, the filter computes the input range and maps it linearly to the user-specified output range. The output range defaults to the full dynamic range from pure black to pure white. ๐ค๐ค
Temporal smoothing can be used on the input range to reduce flickering (rapid changes in brightness) caused when small dark or bright objects enter or leave the scene. This is similar to the auto-exposure (automatic gain control) on a video camera, and, like a video camera, it may cause a period of over- or under-exposure of the video. ๐น
The R,G,B channels can be normalized independently, which may cause some color shifting, or linked together as a single channel, which prevents color shifting. Linked normalization preserves hue. Independent normalization does not, so it can be used to remove some color casts. Independent and linked normalization can be combined in any ratio. ๐จ
The normalize filter accepts the following options:
blackpt,whiteptโ colors which define the output range. The minimum input value is mapped to theblackpt. The maximum input value is mapped to thewhitept. The defaults areblackandwhiterespectively. Specifyingwhiteforblackptandblackforwhiteptwill give color-inverted, normalized video. Shades of grey can be used to reduce the dynamic range (contrast). Specifying saturated colors here can create some interesting effects. ๐smoothingโ the number of previous frames to use for temporal smoothing. The input range of each channel is smoothed using a rolling average over the current frame and thesmoothingprevious frames. The default is0(no temporal smoothing). ๐ฐ๏ธindependenceโ controls the ratio of independent (color shifting) channel normalization to linked (color preserving) normalization.0.0is fully linked,1.0is fully independent. Defaults to1.0(fully independent). ๐strengthโ overall strength of the filter.1.0is full strength.0.0is a rather expensive no-op. Defaults to1.0(full strength). ๐ช
Commands ๐ฌ
This filter supports same commands as options, excluding the smoothing option. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. โ ๏ธ
Examples โจ
- Stretch video contrast to use the full dynamic range, with no temporal smoothing; may flicker depending on the source content:
normalize=blackpt=black:whitept=white:smoothing=0
- As above, but with 50 frames of temporal smoothing; flicker should be reduced, depending on the source content:
normalize=blackpt=black:whitept=white:smoothing=50
- As above, but with hue-preserving linked channel normalization:
normalize=blackpt=black:whitept=white:smoothing=50:independence=0
- As above, but with half strength:
normalize=blackpt=black:whitept=white:smoothing=50:independence=0:strength=0.5
- Map the darkest input color to red, the brightest input color to cyan:
normalize=blackpt=red:whitept=cyan
null ๐ซฅ
Pass the video source unchanged to the output. Literally no thoughts, head empty. ๐ญ
ocio ๐จ
OpenColorIO library filter.
This filter allows you to do color management using the OpenColorIO library. See https://opencolorio.org/ for more details. To enable compilation of this filter, you need to configure FFmpeg with --enable-libopencolorio. ๐จ
It accepts the following options:
configโ by default the filter will use the OCIO config defined by the OCIO environment variable, but this parameter allows you to explicitly specify its location. If you are getting started, you can useconfig=ocio://studio-config-v1.0.0_aces-v1.3_ocio-v2.1which specifies one of the built in defaults. โ๏ธinputโ set the input colorspace. ๐ฅoutputโ set the output colorspace. ๐คdisplayโ set the display colorspace, used in combination withview. ๐ฅ๏ธviewโ set the view colorspace, used in combination withdisplay. ๐inverseโ when used in combination withdisplayandview, this inverts the transform, so going from a display/view to the"input colorspace". ๐filetransformโ lets you point at an external file-transform instead of the OCIO config file. Super handy when you just need to apply one single transform and you do not feel like dragging a whole OCIO config file along for the ride ๐formatโ lets you set the outputpix_fmtof the OCIO filter. And bestie, this has to be an RGB colorspace, so you are genuinely limited torgb24,rgba,rgb48,rgba48,gbrp10,gbrp12,gbrpf32le,gbrapf32le. For most encoding we would recommendrgb48โจcontext_paramsโ lets you pass extra context parameters to the OCIO filter. It's a list ofkey=valuepairs, separated by colons ๐
โจ Examples โจ
Map from ACEScg to ACEScct โ this assumes the OCIO file is defined with the OCIO environment variable.
input=ACEScg:output=ACEScct:format=rgb48
Map from ACEScg to an sRGB display using the "ACES 1.0 - SDR Video" view transform โ this also assumes the OCIO file is defined with the OCIO environment variable. Heads up: you will need to wrap the argument in quotes so those spaces get interpreted correctly ๐
input=ACEScg:display=sRGB - Display:view=ACES 1.0 - SDR Video:format=rgb48
Same thing as above, but using the OCIO file studio-config-v1.0.0_aces-v1.3_ocio-v2.1_ns.ocio instead of the OCIO environment variable:
config=studio-config-v1.0.0_aces-v1.3_ocio-v2.1_ns.ocio:input=ACEScg:display=sRGB - Display:view=ACES 1.0 - SDR Video:format=rgb48
If you are converting to YCrCb you still want to set the color matrix for the conversion. This one is a genuinely good example of combining the two ๐ซถ
ffmpeg -y -i SOURCEFRAMES.%05d.exr -c:v libx265 -vf "ocio=input=ACEScg:output=ACEScct:format=rgb48,scale=in_color_matrix=bt709:out_color_matrix=bt709,format=yuv444p10" OUTPUTFILE.mov
ocr
Optical Character Recognition ๐
This filter uses Tesseract for optical character recognition. To enable compilation of this filter, you need to configure FFmpeg with --enable-libtesseract.
It accepts the following options:
datapathโ setdatapathto the tesseract data. Default behavior is to use whatever was set at installation.languageโ set the language, default is"eng".whitelistโ set the character whitelist.blacklistโ set the character blacklist.
The filter exports the recognized text as the frame metadata lavfi.ocr.text ๐ The filter exports the confidence of recognized words as the frame metadata lavfi.ocr.confidence.
ocv
Apply a video transform using libopencv.
To enable this filter, install the libopencv library and headers and configure FFmpeg with --enable-libopencv.
It accepts the following parameters:
filter_nameโ the name of the libopencv filter to apply.filter_paramsโ the parameters to pass to the libopencv filter. If not specified, the default values are assumed.
Refer to the official libopencv documentation for more precise info: http://docs.opencv.org/master/modules/imgproc/doc/filtering.html
Several libopencv filters are supported โ see the following subsections, bestie ๐
dilate
Dilate an image by using a specific structuring element. It corresponds to the libopencv function cvDilate.
It accepts the parameters: struct_el|nb_iterations.
struct_el represents a structuring element, and has the syntax: colsxrows+anchor_xxanchor_y/shape
cols and rows represent the number of columns and rows of the structuring element, anchor_x and anchor_y the anchor point, and shape the shape for the structuring element. shape must be "rect", "cross", "ellipse", or "custom".
If the value for shape is "custom", it must be followed by a string of the form "=filename". The file with name filename is assumed to represent a binary image, with each printable character corresponding to a bright pixel. When a custom shape is used, cols and rows are ignored, and the number of columns and rows of the read file are assumed instead.
The default value for struct_el is "3x3+0x0/rect".
nb_iterations specifies the number of times the transform is applied to the image, and defaults to 1.
Some examples:
# Use the default values
ocv=dilate
# Dilate using a structuring element with a 5x5 cross, iterating two times
ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
# Read the shape from the file diamond.shape, iterating two times.
# The file diamond.shape may contain a pattern of characters like this
# *
# ***
# *****
# ***
# *
# The specified columns and rows are ignored
# but the anchor point coordinates are not
ocv=dilate:0x0+2x2/custom=diamond.shape|2
erode
Erode an image by using a specific structuring element. It corresponds to the libopencv function cvErode.
It accepts the parameters: struct_el:nb_iterations, with the same syntax and semantics as the dilate filter.
smooth
Smooth the input video โจ
The filter takes the following parameters: type|param1|param2|param3|param4.
type is the type of smooth filter to apply, and must be one of these values: "blur", "blur_no_scale", "median", "gaussian", or "bilateral". The default value is "gaussian".
The meaning of param1, param2, param3, and param4 depends on the smooth type. param1 and param2 accept integer positive values or 0. param3 and param4 accept floating point values.
The default value for param1 is 3. The default value for the other parameters is 0.
These parameters correspond to the parameters assigned to the libopencv function cvSmooth.
oscilloscope
2D Video Oscilloscope ๐
Useful to measure spatial impulse, step responses, chroma delays, etc.
It accepts the following parameters:
xโ set scope center x position.yโ set scope center y position.sโ set scope size, relative to frame diagonal.tโ set scope tilt/rotation.oโ set trace opacity.txโ set trace center x position.tyโ set trace center y position.twโ set trace width, relative to width of frame.thโ set trace height, relative to height of frame.cโ set which components to trace. By default it traces the first three components.gโ draw trace grid. By default it is enabled.stโ draw some statistics. By default it is enabled.scโ draw scope. By default it is enabled.
Commands
This filter supports the same commands as options. The command accepts the same syntax as the corresponding option.
If the specified expression is not valid, it is kept at its current value.
Examples
- Inspect the full first row of a video frame.
oscilloscope=x=0.5:y=0:s=1
- Inspect the full last row of a video frame.
oscilloscope=x=0.5:y=1:s=1
- Inspect the full 5th line of a video frame of height 1080.
oscilloscope=x=0.5:y=5/1080:s=1
- Inspect the full last column of a video frame.
oscilloscope=x=1:y=0.5:s=1:t=1
overlay
Overlay one video on top of another ๐
It takes two inputs and has one output. The first input is the "main" video on which the second input is overlaid.
It accepts the following parameters:
A description of the accepted options follows.
xyโ set the expression for the x and y coordinates of the overlaid video on the main video. Default value is"0"for both expressions. In case the expression is invalid, it is set to a huge value (meaning the overlay will not be displayed within the output visible area).eof_actionโ see framesync.evalโ set when the expressions forxandyare evaluated. It accepts the following values:initโ only evaluate expressions once during filter initialization or when a command is processed.frameโ evaluate expressions for each incoming frame.
Default value is frame.
shortestโ see framesync.formatโ set the format for the output video. It accepts the following values:yuv420โ force YUV 4:2:0 8-bit planar outputyuv420p10โ force YUV 4:2:0 10-bit planar outputyuv422โ force YUV 4:2:2 8-bit planar outputyuv422p10โ force YUV 4:2:2 10-bit planar outputyuv444โ force YUV 4:4:4 8-bit planar outputyuv444p10โ force YUV 4:4:4 10-bit planar outputrgbโ force RGB 8-bit packed outputgbrpโ force RGB 8-bit planar outputautoโ automatically pick format
Default value is yuv420.
repeatlastโ see framesync.alphaโ set the format of the alpha of the overlaid video. It can bestraightorpremultiplied, orautoto choose the alpha mode automatically. Default isauto.
The x and y expressions can contain the following parameters.
main_w,Wmain_h,Hโ the main input width and height.overlay_w,woverlay_h,hโ the overlay input width and height.xyโ the computed values forxandy. They are evaluated for each new frame.hsubvsubโ horizontal and vertical chroma subsample values of the output format. For example, for the pixel format"yuv422p",hsubis2andvsubis1.nโ the number of input frame, starting from0.posโ the position in the file of the input frame,NANif unknown; deprecated, do not use ๐tโ the timestamp, expressed in seconds. It'sNANif the input timestamp is unknown.
This filter also supports the framesync options.
Note that thenandtvariables are available only when evaluation is done per frame, and will evaluate toNANwhenevalis set toinit.
Be aware that frames are taken from each input video in timestamp order, so if their initial timestamps differ, it is a good idea to pass the two inputs through a setpts=PTS-STARTPTS filter to have them begin at the same zero timestamp, just like the example for the movie filter does ๐ซถ
You can chain together more overlays, but you should test the efficiency of such an approach.
Commands
This filter supports the following commands:
xyโ modify thexandyof the overlay input. The command accepts the same syntax as the corresponding option.
If the specified expression is not valid, it is kept at its current value.
Examples
- Draw the overlay at 10 pixels from the bottom right corner of the main video:
overlay=main_w-overlay_w-10:main_h-overlay_h-10
Using named options, the example above becomes:
overlay=x=main_w-overlay_w-10:y=main_h-overlay_h-10
- Insert a transparent PNG logo in the bottom left corner of the input, using the
ffmpegtool with the-filter_complexoption: - Next one in the overlay glow-up tour โ drop a logo in using:
ffmpeg -i input -i logo -filter_complex 'overlay=10:main_h-overlay_h-10' output
- Insert 2 different transparent PNG logos (second logo on bottom right corner) using the ffmpeg tool:
ffmpeg -i input -i logo1 -i logo2 -filter_complex 'overlay=x=10:y=H-h-10,overlay=x=W-w-10:y=H-h-10' output
- Add a transparent color layer on top of the main video;
"WxH"must specify the size of the main input to the overlay filter:
color=color=red@.3:size=WxH [over]; [in][over] overlay [out]
- Play an original video and a filtered version (here with the
deshakefilter) side by side using the ffplay tool:
ffplay input.avi -vf 'split[a][b]; [a]pad=iw*2:ih[src]; [b]deshake[filt]; [src][filt]overlay=w'
The above command is the same as:
ffplay input.avi -vf 'split[b], pad=iw*2[src], [b]deshake, [src]overlay=w'
- Make a sliding overlay appearing from the left to the right top part of the screen starting since time 2:
overlay=x='if(gte(t,2), -w+(t-2)*20, NAN)':y=0
- Compose output by putting two input videos side to side:
ffmpeg -i left.avi -i right.avi -filter_complex "
nullsrc=size=200x100 [background];
[0:v] setpts=PTS-STARTPTS, scale=100x100 [left];
[1:v] setpts=PTS-STARTPTS, scale=100x100 [right];
[background][left] overlay=shortest=1 [background+left];
[background+left][right] overlay=shortest=1:x=100 [left+right]
"
- Mask 10-20 seconds of a video by applying the
delogofilter to a section:
ffmpeg -i test.avi -codec:v:0 wmv2 -ar 11025 -b:v 9000k
-vf '[in]split[split_main][split_delogo];[split_delogo]trim=start=360:end=371,delogo=0:0:640:480[delogoed];[split_main][delogoed]overlay=eof_action=pass[out]'
masked.avi
- Chain several overlays in cascade:
nullsrc=s=200x200 [bg];
testsrc=s=100x100, split=4 [in0][in1][in2][in3];
[in0] lutrgb=r=0, [bg] overlay=0:0 [mid0];
[in1] lutrgb=g=0, [mid0] overlay=100:0 [mid1];
[in2] lutrgb=b=0, [mid1] overlay=0:100 [mid2];
[in3] null, [mid2] overlay=100:100 [out0]
owdenoise
Apply Overcomplete Wavelet denoiser. fancy wavelet math, no thoughts head empty, just vibes and denoising โจ
The filter accepts the following options:
depthโ Set depth.
Larger depth values will denoise lower frequency components more, but slow down filtering. trade-off city, bestie
Must be an int in the range 8-16, default is 8.
luma_strength,lsโ Set luma strength.
Must be a double value in the range 0-1000, default is 1.0.
chroma_strength,csโ Set chroma strength.
Must be a double value in the range 0-1000, default is 1.0.
pad
Add paddings to the input image, and place the original input at the provided x, y coordinates. It's giving picture frame energy ๐ผ๏ธ
It accepts the following parameters:
width,wheight,h
Specify an expression for the size of the output image with the paddings added. If the value for width or height is 0, the corresponding input size is used for the output.
The width expression can reference the value set by the height expression, and vice versa. they talk to each other, it's cute
The default value of width and height is 0.
xy
Specify the offsets to place the input image at within the padded area, with respect to the top/left border of the output image.
The x expression can reference the value set by the y expression, and vice versa.
The default value of x and y is 0.
If x or y evaluate to a negative number, they'll be changed so the input image is centered on the padded area. aww, it self-centers, growth mindset fr
colorโ Specify the color of the padded area. For the syntax of this option, check the "Color" section in the ffmpeg-utils manual.
The default value of color is "black".
evalโ Specify when to evaluatewidth,height,xandyexpression.
It accepts the following values:
initโ Only evaluate expressions once during the filter initialization or when a command is processed.frameโ Evaluate expressions for each incoming frame.
Default value is init.
aspectโ Pad to aspect instead to a resolution.
The value for the width, height, x, and y options are expressions containing the following constants:
in_win_hโ The input video width and height.iwihโ These are the same asin_wandin_h.out_wout_hโ The output width and height (the size of the padded area), as specified by thewidthandheightexpressions.owohโ These are the same asout_wandout_h.xyโ Thexandyoffsets as specified by thexandyexpressions, orNANif not yet specified.aโ same asiw / ihsarโ input sample aspect ratiodarโ input display aspect ratio, it is the same as(iw / ih) * sarhsubvsubโ The horizontal and vertical chroma subsample values. For example for the pixel format"yuv422p"hsubis2andvsubis1.
Examples
- Add paddings with the color
"violet"to the input video. The output video size is640x480, and the top-left corner of the input video is placed at column0, row40:
pad=640:480:0:40:violet
The example above is equivalent to the following command:
pad=width=640:height=480:x=0:y=40:color=violet
- Pad the input to get an output with dimensions increased by 3/2, and put the input video at the center of the padded area:
pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"
- Pad the input to get a squared output with size equal to the maximum value between the input width and height, and put the input video at the center of the padded area:
pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"
- Pad the input to get a final w/h ratio of 16:9:
pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
- In case of anamorphic video, in order to set the output display aspect correctly, it is necessary to use
sarin the expression, according to the relation:
(ih * X / ih) * sar = output_dar
X = output_dar / sar
Thus the previous example needs to be modified to:
pad="ih*16/9/sar:ih:(ow-iw)/2:(oh-ih)/2"
- Double the output size and put the input video in the bottom-right corner of the output padded area:
pad="2*iw:2*ih:ow-iw:oh-ih"
palettegen
Generate one palette for a whole video stream. COLOR TIME ๐จโจ
It accepts the following options:
max_colorsโ Set the maximum number of colors to quantize in the palette. Note: the palette will still contain 256 colors; the unused palette entries will be black. so it's always a 256-slot fit, some slots just get the black fit, iykykreserve_transparentโ Create a palette of 255 colors maximum and reserve the last one for transparency. Reserving the transparency color is useful for GIF optimization. If not set, the maximum of colors in the palette will be 256. You probably want to disable this option for a standalone image. Set by default.transparency_colorโ Set the color that will be used as background for transparency.stats_modeโ Set statistics mode.
It accepts the following values:
fullโ Compute full frame histograms.diffโ Compute histograms only for the part that differs from previous frame. This might be relevant to give more importance to the moving part of your input if the background is static.singleโ Compute new histogram for each frame.
Default value is full.
The filter also exports the frame metadata "lavfi.color_quant_ratio" ("nb_color_in / nb_color_out") which you can use to evaluate the degree of color quantization of the palette. This information is also visible at info logging level. receipts, available on demand
Examples
- Generate a representative palette of a given video using ffmpeg:
ffmpeg -i input.mkv -vf palettegen palette.png
paletteuse
Use a palette to downsample an input video stream. palette goes in, cute lil limited-color video comes out ๐ฆ
The filter takes two inputs: one video stream and a palette. The palette must be a 256 pixels image.
It accepts the following options:
ditherโ Select dithering mode. Available algorithms are:bayerโ Ordered 8x8 bayer dithering (deterministic)heckbertโ Dithering as defined by Paul Heckbert in 1982 (simple error diffusion). Note: this dithering is sometimes considered "wrong" and is included as a reference. elderly algorithm, still on the payroll for reference purposes only, no capfloyd_steinbergโ Floyd and Steingberg dithering (error diffusion)sierra2โ Frankie Sierra dithering v2 (error diffusion)sierra2_4aโ Frankie Sierra dithering v2 "Lite" (error diffusion)sierra3โ Frankie Sierra dithering v3 (error diffusion)burkesโ Burkes dithering (error diffusion)atkinsonโ Atkinson dithering by Bill Atkinson at Apple Computer (error diffusion)noneโ Disable dithering.
Default is sierra2_4a.
bayer_scaleโ Whenbayerdithering is selected, this option defines the scale of the pattern (how much the crosshatch pattern is visible). A low value means more visible pattern for less banding, and higher value means less visible pattern at the cost of more banding.
The option must be an integer value in the range [0,5]. Default is 2.
diff_modeโ If set, define the zone to processrectangleโ Only the changing rectangle will be reprocessed. This is similar to GIF cropping/offsetting compression mechanism. This option can be useful for speed if only a part of the image is changing, and has use cases such as limiting the scope of the error diffusal dither to the rectangle that bounds the moving scene (it leads to more deterministic output if the scene doesn't change much, and as a result less moving noise and better GIF compression).
Default is none.
newโ Take new palette for each output frame.alpha_thresholdโ Sets the alpha threshold for transparency. Alpha values above this threshold will be treated as completely opaque, and values below this threshold will be treated as completely transparent. so dramatic, it's giving all-or-nothing
The option must be an integer value in the range [0,255]. Default is 128.
Examples
- Use a palette (generated for example with
palettegen) to encode a GIF using ffmpeg:
ffmpeg -i input.mkv -i palette.png -lavfi paletteuse output.gif
perspective
Correct perspective of video not recorded perpendicular to the screen. skewed footage? we fix. geometry slay. ๐
A description of the accepted parameters follows โ buckle up bestie, there's a lil list ๐
x0,y0,x1,y1,x2,y2,x3,y3โ these set the coordinates expression for the top left, top right, bottom left and bottom right corners. The default values are"0:0:W:0:0:H:W:H", and with those the perspective just stays exactly the same, no cap. If thesenseoption is set tosource, then the points you specified get sent to the corners of the destination. But ifsenseis set todestination, it flips โ the corners of the source get sent to the coordinates you gave. ๐
The expressions can use these variables, periodt:
W,Hโ the width and height of the video frame.inโ input frame count.onโ output frame count.
interpolationโ sets the interpolation used for perspective correction โจ
It accepts these values:
linearcubic
Default value is linear.
senseโ sets how the coordinate options get interpreted ๐ง
It accepts these values:
0,sourceโ send the point in the source specified by the given coordinates to the corners of the destination.1,destinationโ send the corners of the source to the point in the destination specified by the given coordinates.
Default value is source.
evalโ sets when the expressions for coordinatesx0,y0,...x3,y3actually get evaluated โฐ
It accepts these values:
initโ only evaluate the expressions once during filter initialization, or when a command is processed.frameโ evaluate the expressions for each incoming frame.
Default value is init.
๐ phase
Delays interlaced video by one field time so that the field order flips. The intended use is fixing PAL movies that got captured with the opposite field order to the film-to-video transfer ๐ซ
A description of the accepted parameters follows:
modeโ sets the phase mode.
It accepts these values:
tโ capture field order top-first, transfer bottom-first. The filter delays the bottom field.bโ capture field order bottom-first, transfer top-first. The filter delays the top field.pโ capture and transfer with the same field order. This mode literally only exists so the other options' docs have something to refer to โ but if you actually select it, the filter will faithfully do nothing ๐aโ capture field order determined automatically by field flags, transfer opposite. The filter picks betweentandbmodes frame by frame using field flags. If no field information is available, then it works just likeu.uโ capture unknown or varying, transfer opposite. The filter picks betweentandbframe by frame by analyzing the images and choosing whichever alternative produces the best match between the fields.Tโ capture top-first, transfer unknown or varying. The filter picks betweentandpusing image analysis.Bโ capture bottom-first, transfer unknown or varying. The filter picks betweenbandpusing image analysis.Aโ capture determined by field flags, transfer unknown or varying. The filter picks betweent,bandpusing field flags and image analysis. If no field information is available, then it works just likeU. This is the default mode ๐Uโ both capture and transfer unknown or varying. The filter picks betweent,bandpusing image analysis only.
Commands ๐ซถ
This filter supports all the above options as commands.
๐ฉบ photosensitivity
Reduces the various flashes in video, so it can help users with epilepsy. Genuinely such a kind filter ๐
It accepts these options:
frames,fโ set how many frames to use when filtering. Default is30.threshold,tโ set the detection threshold factor. Default is1. Lower is stricter.skipโ set how many pixels to skip when sampling frames. Default is1. Allowed range is from1to1024.bypassโ leave frames unchanged. Default is disabled.
๐ฌ pixdesctest
Pixel format descriptor test filter, mainly useful for internal testing. The output video should be equal to the input video.
For example:
format=monow, pixdesctest
can be used to test the monowhite pixel format descriptor definition.
๐๏ธ pixelize
Applies pixelization to the video stream. Big chunky vibes, honestly iconic.
The filter accepts these options:
width,w,height,hโ set the block dimensions used for pixelization. Default value is16.mode,mโ set the mode of pixelization used.
Possible values are:
avgminmax
Default value is "avg".
planes,pโ set what planes to filter. Default is to filter all planes.
Commands
This filter supports all options as commands.
๐ pixscope
Displays sample values of color channels. Mainly useful for checking color and levels. Minimum supported resolution is 640x480 ๐
The filters accept these options:
xโ set scope X position, relative offset on the X axis.yโ set scope Y position, relative offset on the Y axis.wโ set scope width.hโ set scope height.oโ set window opacity. This window also holds statistics about the pixel area.wxโ set window X position, relative offset on the X axis.wyโ set window Y position, relative offset on the Y axis.
Commands
This filter supports the same commands as options.
๐งผ pp7
Applies Postprocessing filter 7. It's a variant of the spp filter, similar to spp = 6 with 7 point DCT, where only the center sample is used after IDCT.
The filter accepts these options:
qpโ force a constant quantization parameter. It accepts an integer in range0to63. If it's not set, the filter will use the QP from the video stream (if available).modeโ set thresholding mode. Available modes are:hardโ set hard thresholding.softโ set soft thresholding (better de-ringing effect, but likely blurrier).mediumโ set medium thresholding (good results, default).
โจ premultiply
Applies the alpha premultiply effect to the input video stream, using the first plane of the second stream as alpha.
Both streams must have the same dimensions and the same pixel format, no exceptions bestie.
The filter accepts this option:
planesโ set which planes will be processed; unprocessed planes get copied. By default value is0xf, so all planes get processed.inplaceโ don't require a 2nd input for processing, instead use the alpha plane from the input stream.
๐ฆ premultiply_dynamic
Dynamically premultiplies or unpremultiplies the input video stream as needed, to match what the downstream filter graph requires. This is roughly equivalent to either "premultiply:inplace=yes" or "unpremultiply:inplace=yes", or otherwise a noop. It's giving adaptive queen ๐
The filter accepts this option:
planesโ set which planes will be processed; unprocessed planes get copied. By default value is0xf, all planes will be processed.
๐ธ prewitt
Applies the prewitt operator to the input video stream.
The filter accepts these options:
planesโ set which planes will be processed; unprocessed planes get copied. By default value is0xf, all planes will be processed.scaleโ set the value which will be multiplied with the filtered result.deltaโ set the value which will be added to the filtered result.
Commands
This filter supports all the above options as commands.
๐ pseudocolor
Alters frame colors in video with pseudocolors. Lowkey a whole aesthetic upgrade.
This filter accepts these options:
c0โ set pixel first component expression.c1โ set pixel second component expression.c2โ set pixel third component expression.c3โ set pixel fourth component expression, corresponds to the alpha component.index,iโ set the component to use as the base for altering colors.preset,pโ pick one of the built-in LUTs. By default it's set tonone.
Available LUTs:
magmainfernoplasmaviridisturbocividisrange1range2shadowshighlightssolarnominalpreferredtotalspectralcoolheatfierybluesgreenhelix
opacityโ set the opacity of output colors. Allowed range is from0to1. Default value is1.
Each of the expression options specifies which expression to use for computing the lookup table for the corresponding pixel component values.
The expressions can contain these constants and functions:
w,hโ the input width and height.valโ the input value for the pixel component.ymin,umin,vmin,aminโ the minimum allowed component value.ymax,umax,vmax,amaxโ the maximum allowed component value.
All expressions default to "val".
Commands
This filter supports all the above options as commands.
Examples
- Change too high luma values to gradient:
pseudocolor="'if(between(val,ymax,amax),lerp(ymin,ymax,(val-ymax)/(amax-ymax)),-1):if(between(val,ymax,amax),lerp(umax,umin,(val-ymax)/(amax-ymax)),-1):if(between(val,ymax,amax),lerp(vmin,vmax,(val-ymax)/(amax-ymax)),-1):-1'"
๐ psnr
Obtains the average, maximum and minimum PSNR (Peak Signal to Noise Ratio) between two input videos.
This filter takes two input videos โ the first input is considered the "main" source and gets passed unchanged to the output. The second input is used as a "reference" video for computing the PSNR. ๐ฏ
Both video inputs must have the same resolution and pixel format for this filter to work correctly. It also assumes both inputs have the same number of frames, and those get compared one by one.
The obtained average PSNR is printed through the logging system.
The filter stores the accumulated MSE (mean squared error) of each frame, and at the end of processing it's averaged across all frames equally, and this formula is applied to obtain the PSNR:
PSNR = 10*log10(MAX^2/MSE)
Where MAX is the average of the maximum values of each component of the image.
The description of the accepted parameters follows:
stats_file,fโ if specified, the filter will use the named file to save the PSNR of each individual frame. When the filename equals"-", the data is sent to standard output.stats_versionโ specifies which version of the stats file format to use. Details of each format are written below. Default value is1.output_maxโ controls whether the max value gets written to the stats log. Default is0. Needsstats_version >= 2. And if you set this whilestats_version < 2, the filter will โจthrow an errorโจ at you, so don't do that.
This filter also supports the framesync options, btw.
The file that gets printed when stats_file is selected contains a sequence of key/value pairs of the form key:value for each compared couple of frames. Cute, right?
If you specify a stats_version greater than 1, a header line comes before the list of per-frame-pair stats, with key value pairs following the frame format, with these parameters:
psnr_log_versionโ the version of the log file format. It'll matchstats_version. Slay, consistency.fieldsโ a comma separated list of the per-frame-pair parameters included in the log.
A description of each shown per-frame-pair parameter follows, bestie, don't scroll:
nโ sequential number of the input frame, starting from1.mse_avgโ Mean Square Error pixel-by-pixel average difference of the compared frames, averaged over all the image components.mse_y,mse_u,mse_v,mse_r,mse_g,mse_b,mse_aโ Mean Square Error pixel-by-pixel average difference of the compared frames for the component specified by the suffix.psnr_y,psnr_u,psnr_v,psnr_r,psnr_g,psnr_b,psnr_aโ Peak Signal to Noise ratio of the compared frames for the component specified by the suffix.max_avg,max_y,max_u,max_vโ Maximum allowed value for each channel, and average over all channels.
Examples
- okay so for example:
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
[main][ref] psnr="stats_file=stats.log" [out]
On this example the input file being processed is compared with the reference file ref_movie.mpg. The PSNR of each individual frame is stored in stats.log. Obsessed with the logs honestly.
- another example with different containers:
ffmpeg -i main.mpg -i ref.mkv -lavfi "[0:v]settb=AVTB,setpts=PTS-STARTPTS[main];[1:v]settb=AVTB,setpts=PTS-STARTPTS[ref];[main][ref]psnr" -f null -
pullup
Pulldown reversal (inverse telecine) filter, capable of handling mixed hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive content. It's giving "undo the telecine", fr fr ๐
The pullup filter is designed to take advantage of future context in making its decisions. This filter is stateless in the sense that it does not lock onto a pattern to follow โ instead it looks forward to the following fields in order to identify matches and rebuild progressive frames. Future context main character energy ๐
To produce content with an even framerate, insert the fps filter after pullup, use fps=24000/1001 if the input frame rate is 29.97fps, fps=24 for 30fps and the (rare) telecined 25fps input.
The filter accepts the following options:
jl,jr,jt,jbโ these options set the amount of "junk" to ignore at the left, right, top, and bottom of the image, respectively. Left and right are in units of8pixels, while top and bottom are in units of2lines. The default is8pixels on each side. bye junk โ๏ธsbโ set the strict breaks. Setting this option to1will reduce the chances of filter generating an occasional mismatched frame, but it may also cause an excessive number of frames to be dropped during high motion sequences. Conversely, setting it to-1will make filter match fields more easily. This may help processing of video where there is slight blurring between the fields, but may also cause there to be interlaced frames in the output. Default value is0. It's a tradeoff, bestie, pick your fighter.mpโ set the metric plane to use. It accepts the following values:lโ use luma plane.uโ use chroma blue plane.vโ use chroma red plane.
This option may be set to use chroma plane instead of the default luma plane for doing filter's computations. This may improve accuracy on very clean source material, but more likely will decrease accuracy, especially if there is chroma noise (rainbow effect) or any grayscale video. The main purpose of setting mp to a chroma plane is to reduce CPU load and make pullup usable in realtime on slow machines. Lowkey a whole personality trait of this filter.
For best results (without duplicated frames in the output file) it is necessary to change the output frame rate. Like, actually necessary. For example, to inverse telecine NTSC input:
ffmpeg -i input -vf pullup -r 24000/1001 ...
qp
Change video quantization parameters (QP). Little numbers, big mood.
The filter accepts the following option:
qpโ set expression for quantization parameter.
The expression is evaluated through the eval API and can contain, among others, the following constants:
knownโ1if index is not129,0otherwise. (yes, that's the whole rule, iconic)qpโ sequential index starting from-129to128.
Examples
- some equation like:
qp=2+2*sin(PI*qp)
qrencode
Generate a QR code using the libqrencode library (see <https://fukuchi.org/works/qrencode/>), and overlay it on top of the current frame. QR codes on video, we love to see it ๐ฆ
To enable the compilation of this filter, you need to configure FFmpeg with --enable-libqrencode. Don't forget or you'll be sad.
The QR code is generated from the provided text or text pattern. The corresponding QR code is scaled and overlaid into the video output according to the specified options.
In case no text is specified, no QR code is overlaied. (That's a typo in the og source and I'm keeping it, it's part of the vibe now ๐ โ the point: no text means no QR code at all.)
The filter accepts the following options:
qrcode_width,qandpadded_qrcode_width,Qโ specify an expression for the width of the rendered QR code, with and without padding. Theqrcode_widthexpression can reference the value set by thepadded_qrcode_widthexpression, and vice versa. By defaultpadded_qrcode_widthis set toqrcode_width, meaning that there is no padding.
These expressions are evaluated for each new frame.
See the qrencode Expressions section for details. ๐
x,yโ specify an expression for positioning the padded QR code top-left corner. Thexexpression can reference the value set by theyexpression, and vice.
By default x and y are set set to 0, meaning that the QR code is placed in the top left corner of the input. (yes, "set set", again, that's literally what the og says, love that for us ๐)
These expressions are evaluated for each new frame.
See the qrencode Expressions section for details.
case_sensitive,csโ instruct libqrencode to use case sensitive encoding. This is enabled by default. This can be disabled to reduce the QR encoding size. Smaller code, less case drama.level,lโ specify the QR encoding error correction level. With an higher correction level, the encoding size will increase but the code will be more robust to corruption. Lower level isL.
It accepts the following values:
LMQH
expansionโ select how the input text is expanded. Can be eithernone, ornormal(default). See theqrencodeText expansion section below for details.text,textfileโ define the text to be rendered. In case neither is specified, no QR is encoded (just an empty colored frame).
In case expansion is enabled, the text is treated as a text template, using the qrencode expansion mechanism. See the qrencode Text expansion section below for details.
background_color,bcandforeground_color,fcโ set the QR code and background color. The default value offoreground_colorisblack, the default value ofbackground_coloriswhite.
For the syntax of the color options, check the "Color" section in the ffmpeg-utils manual. Colors are a whole vibe, go wild ๐
qrencode Expressions
The expressions set by the options contain the following constants and functions.
darโ input display aspect ratio, it is the same as(w / h) * sardurationโ the current frame's duration, in secondshsub,vsubโ horizontal and vertical chroma subsample values. For example for the pixel formatyuv422phsubis2andvsubis1.main_h,Hโ the input heightmain_w,Wโ the input widthnโ the number of input frame, starting from0pict_typeโ a number representing the picture typeqr_w,wโ the width of the encoded QR coderendered_qr_w,qandrendered_padded_qr_w,Qโ the width of the rendered QR code, without and without padding. (Yep, that's how the source reads, "without and without" โ I'm not touching it, I just work here ๐ The next line is the part that actually matters:)
These parameters allow the q and Q expressions to refer to each other, so you can for example specify q=3/4*Q. Mutual reference, so cute.
rand(min, max)โ return a random number included between min and maxsarโ the input sample aspect ratiotโ timestamp expressed in seconds,NANif the input timestamp is unknownx,yโ the x and y offset coordinates where the text is drawn.
These parameters allow the x and y expressions to refer to each other, so you can for example specify y=x/dar.
qrencode Text expansion
If expansion is set to none, the text is printed verbatim. No thoughts, just text.
If expansion is set to normal (which is the default), the following expansion mechanism is used.
The backslash character \, followed by any character, always expands to the second character.
Sequences of the form %{...} are expanded. The text between the braces is a function name, possibly followed by arguments separated by ':'. If the arguments contain special characters or delimiters (':' or '}'), they should be escaped.
Note that they probably must also be escaped as the value for thetextoption in the filter argument string and as the filter argument in the filtergraph description, and possibly also for the shell โ that makes up to four levels of escaping ๐ญ using a text file with thetextfileoption avoids these problems. Bestie. Save yourself.
The following functions are available:
n,frame_numโ return the frame number.ptsโ Return the presentation timestamp of the current frame.
It can take up to two arguments.
The first argument is the format of the timestamp; it defaults to flt for seconds as a decimal number with microsecond accuracy; hms stands for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy. gmtime stands for the timestamp of the frame formatted as UTC time; localtime stands for the timestamp of the frame formatted as local time zone time. If the format is set to hms24hh, the time is formatted in 24h format (00-23).
The second argument is an offset added to the timestamp.
If the format is set to localtime or gmtime, a third argument may be supplied: a strftime C function format string. By default, YYYY-MM-DD HH:MM:SS format will be used. Timezones, we stan ๐ซถ
expr,eโ Evaluate the expression's value and output as a double.
It must take one argument specifying the expression to be evaluated, accepting the constants and functions defined in qrencode_expressions.
expr_formatted,efโ evaluates the expression's value and spits it back out as a formatted string โจ
First argument = the expression to evaluate, literally the same deal as the expr function. Second argument = the output format. Allowed values are x, X, d and u, and they're treated exactly as in the "printf" function. Third parameter is optional and sets the number of positions taken by the output โ perfect for zero-padding from the left ๐
gmtimeโ the time at which the filter is running, expressed in UTC โฐ
It can take an argument: a "strftime" C function format string. That format string is extended to support the variable %[1-6]N, which prints fractions of the second with an optionally specified number of digits. fancy.
localtimeโ the time at which the filter is running, expressed in the local time zone ๐
Same deal: it accepts an argument, a "strftime" C function format string, and that format string is extended to support %[1-6]N which prints fractions of the second with optionally specified number of digits.
metadataโ frame metadata. Takes one or two arguments ๐
The first argument is mandatory and specifies the metadata key.
The second argument is optional and specifies a default value, used when the metadata key is not found or empty.
You can figure out what metadata is available by inspecting entries starting with TAG included within each frame section printed by running ffprobe -show_frames. String metadata generated in filters leading to the qrencode filter is also available ๐
rand(min, max)โ returns a random number included between min and max ๐ฒ
โจ Examples โจ
- Generate a QR code encoding the specified text with the default size, overlaid in the top left corner of the input video, with the default size:
qrencode=text=www.ffmpeg.org
- Same as below, but select blue on pink colors ๐ฆ:
qrencode=text=www.ffmpeg.org:bc=pink@0.5:fc=blue
- Place the QR code in the bottom right corner of the input video:
qrencode=text=www.ffmpeg.org:x=W-Q:y=H-Q
- Generate a QR code with width of 200 pixels and padding, making the padded width 4/3 of the QR code width:
qrencode=text=www.ffmpeg.org:q=200:Q=4/3*q
- Generate a QR code with padded width of 200 pixels and padding, making the QR code width 3/4 of the padded width:
qrencode=text=www.ffmpeg.org:Q=200:q=3/4*Q
- Make the QR code a fraction of the input video width:
qrencode=text=www.ffmpeg.org:q=W/5
- Generate a QR code encoding the frame number:
qrencode=text=%{n}
- Generate a QR code encoding the GMT timestamp:
qrencode=text=%{gmtime}
- Generate a QR code encoding the timestamp expressed as a float:
qrencode=text=%{pts}
๐ต๏ธ quirc
Identify and decode a QR code using the libquirc library (see <https://github.com/dlbeer/quirc/>), and print the identified QR codes positions and payload as metadata. it's giving detective mode fr fr ๐
To enable the compilation of this filter, you need to configure FFmpeg with --enable-libquirc.
For each found QR code in the input video, some metadata entries are added with the prefix lavfi.quirc.N, where N is the index, starting from 0, associated to the QR code.
A description of each metadata value follows:
lavfi.quirc.countโ the number of found QR codes; it is not set in case none was found ๐lavfi.quirc.N.corner.M.xlavfi.quirc.N.coreer.M.yโ the x/y positions of the four corners of the square containing the QR code, where M is the index of the corner starting from 0lavfi.quirc.N.payloadโ the payload of the QR code
๐ฐ random
Flush video frames from internal cache of frames into a random order. No frame is discarded. Inspired by the frei0r nervous filter โจ
framesโ set size in number of frames of internal cache, in range from2to512. Default is30.seedโ set seed for random number generator, must be an integer included between0and"UINT32_MAX". If not specified, or if explicitly set to less than0, the filter will try to use a good random seed on a best effort basis ๐ฒ
๐บ readeia608
Read closed captioning (EIA-608) information from the top lines of a video frame.
This filter adds frame metadata for "lavfi.readeia608.X.cc" and "lavfi.readeia608.X.line", where "X" is the number of the identified line with EIA-608 data (starting from 0). A description of each metadata value follows:
lavfi.readeia608.X.ccโ the two bytes stored as EIA-608 data (printed in hexadecimal)lavfi.readeia608.X.lineโ the number of the line on which the EIA-608 data was identified and read
This filter accepts the following options:
scan_minโ set the line to start scanning for EIA-608 data. Default is0.scan_maxโ set the line to end scanning for EIA-608 data. Default is29.spwโ set the ratio of width reserved for sync code detection. Default is0.27. Allowed range is"[0.1 - 0.7]".chpโ enable checking the parity bit. In the event of a parity error, the filter will output0x00for that character. Default isfalse.lpโ lowpass lines prior to further processing. Default is enabled.
Commands
This filter supports the all above options as commands ๐
โจ Examples โจ
- Output a csv with presentation time and the first two lines of identified EIA-608 captioning data:
ffprobe -f lavfi -i movie=captioned_video.mov,readeia608 -show_entries frame=pts_time:frame_tags=lavfi.readeia608.0.cc,lavfi.readeia608.1.cc -of csv
โฑ๏ธ readvitc
Read vertical interval timecode (VITC) information from the top lines of a video frame.
The filter adds frame metadata key "lavfi.readvitc.tc_str" with the timecode value, if a valid timecode has been detected. Further metadata key "lavfi.readvitc.found" is set to 0/1 depending on whether timecode data has been found or not ๐
This filter accepts the following options:
scan_maxโ set the maximum number of lines to scan for VITC data. If the value is set to-1the full video frame is scanned. Default is45.thr_bโ set the luma threshold for black. Accepts float numbers in the range[0.0,1.0], default value is0.2. The value must be equal or less than"thr_w".thr_wโ set the luma threshold for white. Accepts float numbers in the range[0.0,1.0], default value is0.6. The value must be equal or greater than"thr_b".
โจ Examples โจ
- Detect and draw VITC data onto the video frame; if no valid VITC is detected, draw
--:--:--:--as a placeholder:
ffmpeg -i input.avi -filter:v 'readvitc,drawtext=fontfile=FreeMono.ttf:text=%{metadata\\:lavfi.readvitc.tc_str\\:--\\\\\\:--\\\\\\:--\\\\\\:--}:x=(w-tw)/2:y=400-ascent'
๐บ๏ธ remap
Remap pixels using 2nd: Xmap and 3rd: Ymap input video stream.
Destination pixel at position (X, Y) will be picked from source (x, y) position where x = Xmap(X, Y) and y = Ymap(X, Y). If mapping values are out of range, zero value for pixel will be used for destination pixel.
Xmap and Ymap input video streams must be of same dimensions. Output video stream will have Xmap/Ymap video stream dimensions. Xmap and Ymap input video streams are 16bit depth, single channel ๐
formatโ specify pixel format of output from this filter. Can be"color"or"gray". Default is"color".fillโ specify the color of the unmapped pixels. For the syntax of this option, check the"Color"section in the ffmpeg-utils manual. Default color is"black".
๐งผ removegrain
The removegrain filter is a spatial denoiser for progressive video. so clean, so fresh โจ
m0โ set mode for the first plane.m1โ set mode for the second plane.m2โ set mode for the third plane.m3โ set mode for the fourth plane.
Range of mode is from 0 to 24. Description of each mode follows:
0โ leave input plane unchanged. Default.1โ clips the pixel with the minimum and maximum of the 8 neighbour pixels.2โ clips the pixel with the second minimum and maximum of the 8 neighbour pixels.3โ clips the pixel with the third minimum and maximum of the 8 neighbour pixels.4โ clips the pixel with the fourth minimum and maximum of the 8 neighbour pixels. This is equivalent to a median filter.5โ line-sensitive clipping giving the minimal change.6โ line-sensitive clipping, intermediate.7โ line-sensitive clipping, intermediate.8โ line-sensitive clipping, intermediate.9โ line-sensitive clipping on a line where the neighbours pixels are the closest.10โ replaces the target pixel with the closest neighbour.11โ[1 2 1]horizontal and vertical kernel blur.12โ same as mode 11.13โ Bob mode, interpolates top field from the line where the neighbours pixels are the closest.14โ Bob mode, interpolates bottom field from the line where the neighbours pixels are the closest.15โ Bob mode, interpolates top field. Same as 13 but with a more complicated interpolation formula.16โ Bob mode, interpolates bottom field. Same as 14 but with a more complicated interpolation formula.17โ clips the pixel with the minimum and maximum of respectively the maximum and minimum of each pair of opposite neighbour pixels.18โ line-sensitive clipping using opposite neighbours whose greatest distance from the current pixel is minimal.19โ replaces the pixel with the average of its 8 neighbours.20โ averages the 9 pixels ([1 1 1]horizontal and vertical blur).21โ clips pixels using the averages of opposite neighbour.22โ same as mode 21 but simpler and faster.23โ small edge and halo removal, but reputed useless ๐24โ similar as 23.
๐ซ removelogo
Suppress a TV station logo, using an image file to determine which pixels comprise the logo. It works by filling in the pixels that comprise the logo with neighboring pixels. bye bye watermark ๐
The filter accepts the following options:
filename,fโ set the filter bitmap file, which can be any image format supported by libavformat. The width and height of the image file must match those of the video stream being processed.
Pixels in the provided bitmap image with a value of zero are not considered part of the logo, non-zero pixels are considered part of the logo. If you use white (255) for the logo and black (0) for the rest, you will be safe ๐ซถ For making the filter bitmap, it is recommended to take a screen capture of a black frame with the logo visible, and then using a threshold filter followed by the erode filter once or twice.
Okay so real talk: sometimes a few little splotches sneak through and you gotta fix them by hand ๐ . Remember that if logo pixels are not covered, the filter quality will be much reduced. Now โ marking too many pixels as part of the logo doesn't hurt as much, but it will increase the amount of blurring needed to cover over the image and will destroy more information than necessary, and extra pixels will slow things down on a large logo. So like, cover the logo, don't cover the whole vibe check โจ
๐ repeatfields
This filter uses the repeat_field flag from the Video ES headers and hard repeats fields based on its value. No cap, it just takes the flag's word for it ๐ซถ
๐ฆ reverse
Reverse a video clip. Iconic for that "wait what just happened" moment ๐ซ
Warning: this filter requires memory to buffer the entire clip, so trimming is suggested. Your RAM is gonna be working overtime ๐ญ trim first, bestie.
๐ธ Examples
- Take the first 5 seconds of a clip, and reverse it:
trim=end=5,reverse
๐ rgbashift
Shift R/G/B/A pixels horizontally and/or vertically. Little nudge, big energy ๐
The filter accepts the following options:
rhโ set amount to shift red horizontally.rvโ set amount to shift red vertically.ghโ set amount to shift green horizontally.gvโ set amount to shift green vertically.bhโ set amount to shift blue horizontally.bvโ set amount to shift blue vertically.ahโ set amount to shift alpha horizontally.avโ set amount to shift alpha vertically.edgeโ set edge mode, can besmear,default, orwarp.
โก Commands
This filter supports the all above options as commands. Yes, all of them ๐
โญ roberts
Apply roberts cross operator to input video stream. Edge-detection slay ๐ฅ
The filter accepts the following option:
planesโ set which planes will be processed, unprocessed planes will be copied. By default value0xf, all planes will be processed.scaleโ set value which will be multiplied with filtered result.deltaโ set value which will be added to filtered result.
โก Commands
This filter supports the all above options as commands. Same deal, bestie ๐
๐ rotate
Rotate video by an arbitrary angle expressed in radians. Main character energy: the video spins ๐ซ
The filter accepts the following options:
A description of the optional parameters follows.
angle,aโ set an expression for the angle by which to rotate the input video clockwise, expressed as a number of radians. A negative value will result in a counter-clockwise rotation. By default it is set to"0".
This expression is evaluated for each frame. Every. Single. One ๐ค
out_w,owโ set the output width expression, default value is"iw". This expression is evaluated just once during configuration.out_h,ohโ set the output height expression, default value is"ih". This expression is evaluated just once during configuration.bilinearโ enable bilinear interpolation if set to1, a value of0disables it. Default value is1.fillcolor,cโ set the color used to fill the output area not covered by the rotated image. For the general syntax of this option, check the "Color" section in theffmpeg-utilsmanual. If the special value"none"is selected then no background is printed (useful for example if the background is never shown).
Default value is "black".
The expressions for the angle and the output size can contain the following constants and functions:
nโ sequential number of the input frame, starting from 0. It is alwaysNANbefore the first frame is filtered.tโ time in seconds of the input frame, it is set to0when the filter is configured. It is alwaysNANbefore the first frame is filtered.hsub,vsubโ horizontal and vertical chroma subsample values. For example for the pixel format"yuv422p"hsubis 2 andvsubis 1.in_w,iw,in_h,ihโ the input video width and heightout_w,ow,out_h,ohโ the output width and height, that is the size of the padded area as specified by the width and height expressionsrotw(a),roth(a)โ the minimal width/height required for completely containing the input video rotated by a radians.
These are only available when computing the out_w and out_h expressions. Like, only there, nowhere else ๐ซ
๐ธ Examples
- Rotate the input by PI/6 radians clockwise:
rotate=PI/6
- Rotate the input by PI/6 radians counter-clockwise:
rotate=-PI/6
- Rotate the input by 45 degrees clockwise:
rotate=45*PI/180
- Apply a constant rotation with period T, starting from an angle of PI/3:
rotate=PI/3+2*PI*t/T
- Make the input video rotation oscillating with a period of T seconds and an amplitude of A radians:
rotate=A*sin(2*PI/T*t)
- Rotate the video, output size is chosen so that the whole rotating input video is always completely contained in the output:
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
- Rotate the video, reduce the output size so that no background is ever shown:
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
โก Commands
The filter supports the following commands:
a,angleโ set the angle expression. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. No crash, no drama, it just stays put ๐
๐ง sab
Apply Shape Adaptive Blur. Soft-focus filter, but make it smart โจ
The filter accepts the following options:
luma_radius,lrโ set luma blur filter strength, must be a value in range0.1-4.0, default value is1.0. A greater value will result in a more blurred image, and in slower processing.luma_pre_filter_radius,lpfrโ set luma pre-filter radius, must be a value in the0.1-2.0range, default value is1.0.luma_strength,lsโ set luma maximum difference between pixels to still be considered, must be a value in the0.1-100.0range, default value is1.0.chroma_radius,crโ set chroma blur filter strength, must be a value in range-0.9-4.0. A greater value will result in a more blurred image, and in slower processing.chroma_pre_filter_radius,cpfrโ set chroma pre-filter radius, must be a value in the-0.9-2.0range.chroma_strength,csโ set chroma maximum difference between pixels to still be considered, must be a value in the-0.9-100.0range.
Each chroma option value, if not explicitly specified, is set to the corresponding luma option value. So chroma just copies luma's notes, honestly kind of a mood ๐ซถ
๐ scale
Scale (resize) the input video, using the libswscale library. This is the filter, the icon, the legend ๐
The scale filter forces the output display aspect ratio to be the same of the input, by changing the output sample aspect ratio.
If the input image format is different from the format requested by the next filter, the scale filter will convert the input to the requested format. It's giving adaptable ๐
๐ Options
The filter accepts the following options, any of the options supported by the libswscale scaler, as well as any of the framesync options.
See the ffmpeg-scaler manual for the complete list of scaler options.
width,w/height,hโ set the output video dimension expression. Default value is the input dimension.
If the width or w value is 0, the input width is used for the output. If the height or h value is 0, the input height is used for the output.
If one and only one of the values is -n with n >= 1, the scale filter will use a value that maintains the aspect ratio of the input image, calculated from the other specified dimension. After that it will, however, make sure that the calculated dimension is divisible by n and adjust the value if necessary.
If both values are -n with n >= 1, the behavior will be identical to both values being set to 0 as previously detailed.
See below for the list of accepted constants for use in the dimension expression.
evalโ specify when to evaluatewidthandheightexpression. It accepts the following values:initโ only evaluate expressions once during the filter initialization or when a command is processed.frameโ evaluate expressions for each incoming frame.
Default value is init.
interlโ set the interlacing mode. It accepts the following values:1โ force interlaced aware scaling.0โ do not apply interlaced scaling.-1โ select interlaced aware scaling depending on whether the source frames are flagged as interlaced or not.
Default value is 0.
flagsโ setlibswscalescaling flags. See theffmpeg-scalermanual for the complete list of values. If not explicitly specified the filter applies the default flags.param0,param1โ setlibswscaleinput parameters for scaling algorithms that need them. See theffmpeg-scalermanual for the complete documentation. If not explicitly specified the filter applies empty parameters.intentโ set the ICC rendering intent to use when transforming between different color spaces. It accepts the following values:perceptualโ use a perceptually guided tone and gamut mapping curve. The exact details of the mapping used may change at any time and should not be relied on as stable. This intent is recommended for final viewing of image/video content in typical viewing settings.relative_colorimetricโ statically clip out-of-gamut colors using a colorimetric clipping curve which attempts to find the colorimetrically least dissimilar in-gamut color. This intent performs white point adaptation and black point adaptation. This is the default. This intent is recommended wherever faithful color reproduction is of the utmost importance, even at the cost of clipping.absolute_colorimetricโ hard clip out-of-gamut colors with no attempt at white or black point reproduction. This intent will reproduce in-gamut colors 1:1 on the output display as they would appear on the reference display, assuming the output display is appropriately calibrated.saturationโ performs saturation mapping - that is, stretches the input color volume directly onto the output color volume, in non-linear fashion that preserves the original signal appearance as much as possible. This intent is recommended for signal content evaluation, as it will not lead to any clipping. It is roughly analogous to not performing any color mapping, although it still takes into account the mastering display primaries and any differences in encoding TRC.
size,sโ set the video size. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual.in_color_matrix,out_color_matrixโ set in/output YCbCr color space type.
This option lets you override the autodetected value and force a specific one for the output and the encoder. If you donโt specify it, the color space type depends on the pixel format. Possible values are literally:
autoโ choose automatically.bt709โ format conforming to International Telecommunication Union (ITU) Recommendation BT.709.fccโ set color space conforming to the United States Federal Communications Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).bt601,bt470,smpte170mโ set color space conforming to:- ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
- ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
- Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
smpte240mโ set color space conforming to SMPTE ST 240:1999.bt2020โ set color space conforming to ITU-R BT.2020 non-constant luminance system.
in_range,out_rangeโ set in/output YCbCr sample range. This lets you override the autodetected value and force a specific one for the output and encoder. If not specified, the range depends on the pixel format. Possible values:auto/unknownโ choose automatically.jpeg/full/pcโ set full range (0-255in case of 8-bit luma).mpeg/limited/tvโ set"MPEG"range (16-235in case of 8-bit luma).
in_chroma_loc,out_chroma_locโ set in/output chroma sample location. If not specified, center-sited chroma is used by default. Possible values:auto,unknownleftcentertoplefttopbottomleftbottom
in_primaries,out_primariesโ set in/output RGB primaries. This lets you override the autodetected value and force a specific one for the output and encoder. Possible values:autoโ choose automatically. This is the default.- Other possible values are
bt709,bt470m,bt470bg,smpte170m,smpte240m,film,bt2020,smpte428,smpte431,smpte432,jedec-p22,ebu3213.
in_transfer,out_transferโ set in/output transfer response curve (TRC). This lets you override the autodetected value and force a specific one for the output and encoder. Possible values:autoโ choose automatically. This is the default.- Other possible values are
bt709,bt470m,gamma22,bt470bg,gamma28,smpte170m,smpte240m,linear,iec61966-2-1,srgb,iec61966-2-4,xvycc,bt1361e,bt2020-10,bt2020-12,smpte2084,smpte428,arib-std-b67.
force_original_aspect_ratioโ enable decreasing or increasing output video width or height if necessary to keep the original aspect ratio. Possible values:disableโ scale the video as specified and disable this feature.decreaseโ the output video dimensions will automatically be decreased if needed.increaseโ the output video dimensions will automatically be increased if needed.
One useful instance of this option is when you know a specific deviceโs maximum allowed resolution: you can use this to limit the output video to that while retaining the aspect ratio. For example, device A allows 1280x720 playback, and your video is 1920x800. Using this option (set it to decrease) and specifying 1280x720 to the command line makes the output 1280x533.
Please note that this is a different thing than specifying -1 for w or h โ you still need to specify the output resolution for this option to work.
force_divisible_byโ ensures that both the output dimensions, width and height, are divisible by the given integer when used together withforce_original_aspect_ratio. This works similar to using"-n"in thewandhoptions.
This option respects the value set for force_original_aspect_ratio, increasing or decreasing the resolution accordingly. The videoโs aspect ratio may be slightly modified.
This option can be handy if you need to have a video fit within or exceed a defined resolution using force_original_aspect_ratio but also have encoder restrictions on width or height divisibility.
reset_sarโ enabling this option leads to the output SAR being reset to1. Additionally, if the user requests proportional scaling either through the width or height expressions, e.g."w=-4:h=360"or"w=iw/2:h=-1"or by enabling"force_original_aspect_ratio", then the input DAR is taken into account and the output is scaled to produce square pixels. Default isfalse.
The values of the w and h options are expressions containing the following constants:
in_w,in_hโ the input width and height.iw,ihโ these are the same asin_wandin_h.out_w,out_hโ the output (scaled) width and height.ow,ohโ these are the same asout_wandout_h.aโ the same asiw / ih.sarโ input sample aspect ratio.darโ the input display aspect ratio. Calculated from(iw / ih) * sar.hsub,vsubโ horizontal and vertical input chroma subsample values. For example, for the pixel formatyuv422p,hsubis2andvsubis1.ohsub,ovsubโ horizontal and vertical output chroma subsample values. For example, for the pixel formatyuv422p,hsubis2andvsubis1.nโ the (sequential) number of the input frame, starting from0. Only available witheval=frame.tโ the presentation timestamp of the input frame, expressed as a number of seconds. Only available witheval=frame.posโ the position (byte offset) of the frame in the input stream, orNaNif this information is unavailable and/or meaningless (for example, in case of synthetic video). Only available witheval=frame. ๐จ Deprecated, do not use.ref_w,rw;ref_h,rh;ref_a;ref_dar,rdar;ref_n;ref_t;ref_posโ equivalent to the above, but for a second reference input. If any of these variables are present, this filter accepts two inputs.
Examples ๐ฌ
- Scale the input video to a size of
200x100:
scale=w=200:h=100
This is equivalent to:
scale=200:100
or:
scale=200x100
- Specify a size abbreviation for the output size:
scale=qcif
which can also be written as:
scale=size=qcif
- Scale the input to 2x:
scale=w=2*iw:h=2*ih
- The above is the same as:
scale=2*in_w:2*in_h
- Scale the input to 2x with forced interlaced scaling:
scale=2*iw:2*ih:interl=1
- Scale the input to half size:
scale=w=iw/2:h=ih/2
- Increase the width, and set the height to the same size:
scale=3/2*iw:ow
- Seek Greek harmony:
scale=iw:1/PHI*iw
scale=ih*PHI:ih
- Increase the height, and set the width to 3/2 of the height:
scale=w=3/2*oh:h=3/5*ih
- Increase the size, making the size a multiple of the chroma subsample values:
scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
- Increase the width to a maximum of 500 pixels, keeping the same aspect ratio as the input:
scale=w='min(500\, iw*3/2):h=-1'
- Make pixels square by combining
scaleandsetsar:
scale='trunc(ih*dar):ih',setsar=1/1
- Make pixels square using
reset_sar, making sure the resulting resolution is even (required by some codecs):
scale='-2:ih-mod(ih,2):reset_sar=1'
- Scale to target exactly, however reset SAR to
1:
scale='400:300:reset_sar=1'
- Scale to even dimensions that fit within
400x300, preserving input SAR:
scale='400:300:force_original_aspect_ratio=decrease:force_divisible_by=2'
- Scale to produce square pixels with even dimensions that fit within
400x300:
scale='400:300:force_original_aspect_ratio=decrease:force_divisible_by=2:reset_sar=1'
- Scale a subtitle stream (
sub) to match the main video (main) in size before overlaying. ("scale2ref")
'[main]split[a][b]; [ref][a]scale=rw:rh[c]; [b][c]overlay'
- Scale a logo to 1/10th the height of a video, while preserving its display aspect ratio.
[logo-in][video-in]scale=w=oh*dar:h=rh/10[logo-out]
Commands ๐ฌ โ this filter supports:
width,w;height,hโ set the output video dimension expression. The command accepts the same syntax of the corresponding option. If the specified expression is not valid, it is kept at its current value.
scharr ๐พ
Apply scharr operator to input video stream. The filter accepts the following options:
planesโ set which planes will be processed; unprocessed planes will be copied. By default value0xf, all planes will be processed.scaleโ set value which will be multiplied with filtered result.deltaโ set value which will be added to filtered result.
Commands ๐ฌ โ this filter supports all the above options as commands.
scroll ๐
Scroll input video horizontally and/or vertically by constant speed. The filter accepts the following options:
horizontal,hโ set the horizontal scrolling speed. Default is0. Allowed range is from-1to1. Negative values change scrolling direction.vertical,vโ set the vertical scrolling speed. Default is0. Allowed range is from-1to1. Negative values change scrolling direction.hposโ set the initial horizontal scrolling position. Default is0. Allowed range is from0to1.vposโ set the initial vertical scrolling position. Default is0. Allowed range is from0to1.
Commands ๐ฌ โ this filter supports the following commands:
horizontal,hโ set the horizontal scrolling speed.vertical,vโ set the vertical scrolling speed.
scdet ๐ฌ
Detect video scene change. This filter sets frame metadata with mafd between frame, the scene score, and forwards the frame to the next filter, so they can use these metadata to detect scene change or others.
Also, this filter is a little chatterbox: it logs a message and sets frame metadata whenever it catches a scene change past your threshold. ๐ฌ
The "lavfi.scd.mafd" metadata keys get set with mafd for every single frame.
The "lavfi.scd.score" metadata keys get set with the scene change score for every frame, so you can detect scene changes.
The "lavfi.scd.time" metadata keys get set with the current filtered frame time โ the one that detects a scene change with the threshold.
This filter accepts these options, bestie:
threshold,tโ sets the scene change detection threshold as a percentage of maximum change. The good-values zone is"[8.0, 14.0]", and the allowed range for threshold is"[0., 100.]". Default value is10.๐ฏsc_pass,sโ sets the flag to pass scene change frames to the next filter. Default value is0. You can turn it on if you want to get a snapshot of the scene change frames only. ๐ธ
๐ selectivecolor
This one adjusts cyan, magenta, yellow and black (CMYK) across certain ranges of colors (think "reds", "yellows", "greens", "cyans", ... and so on). The adjustment range is defined by the purity of the color โ like, how saturated it already is. ๐
It's basically the Adobe Photoshop Selective Color tool, but make it command line. โจ
The filter accepts the following options:
correction_methodโ select the color correction method. Available values are:absoluteโ the specified adjustments are applied "as-is" (added/subtracted to the original pixel component value).relativeโ the specified adjustments are relative to the original component value.
Default is "absolute".
redsโ adjustments for red pixels (pixels where the red component is the max) โค๏ธyellowsโ adjustments for yellow pixels (pixels where the blue component is the minimum) ๐greensโ adjustments for green pixels (pixels where the green component is the max) ๐cyansโ adjustments for cyan pixels (pixels where the red component is the minimum) ๐ฉตbluesโ adjustments for blue pixels (pixels where the blue component is the max) ๐magentasโ adjustments for magenta pixels (pixels where the green component is the minimum) ๐whitesโ adjustments for white pixels (pixels where all components are greater than128) ๐คneutralsโ adjustments for all pixels except pure black and pure white ๐ฉถblacksโ adjustments for black pixels (pixels where all components are lesser than128) ๐คpsfileโ specify a Photoshop selective color file (".asv") to import the settings from. ๐
All the adjustment settings (reds, yellows, ...) accept up to 4 space-separated floating point adjustment values in the [-1,1] range โ respectively to adjust how much cyan, magenta, yellow and black goes on the pixels of that range. no cap.
๐ธ Examples
- Increase cyan by 50% and reduce yellow by 33% in every green area, and increase magenta by 27% in blue areas:
selectivecolor=greens=.5 0 -.33 0:blues=0 .27
- Use a Photoshop selective color preset:
selectivecolor=psfile=MySelectiveColorPresets/Misty.asv
โ๏ธ separatefields
The "separatefields" filter takes a frame-based video input and splits each frame into its component fields, producing a new half-height clip with twice the frame rate and twice the frame count. It's giving mitosis, honestly. ๐ฆ
It uses field-dominance info in the frame to decide which of each pair of fields goes first in the output. If it gets it wrong, use the setfield filter before the "separatefields" filter. ๐ง
๐ setdar, setsar
The "setdar" filter sets the Display Aspect Ratio for the filter output video.
It does this by changing the specified Sample (aka Pixel) Aspect Ratio, according to this equation, periodt:
<DAR> = <HORIZONTAL_RESOLUTION> / <VERTICAL_RESOLUTION> * <SAR>
Keep in mind: "setdar" does not modify the pixel dimensions of the video frame. Also, the display aspect ratio set by this filter may get changed by later filters in the filterchain โ like if there's scaling involved, or if another "setdar" or a "setsar" filter gets applied. ๐
The "setsar" filter sets the Sample (aka Pixel) Aspect Ratio for the filter output video.
Note that, as a consequence of applying this filter, the output display aspect ratio will change according to the equation above. lowkey math.
And keep in mind that the sample aspect ratio set by the "setsar" filter may be changed by later filters in the filterchain too โ e.g. if another "setsar" or a "setdar" filter gets applied.
It accepts these parameters:
r,ratio,dar("setdar"only),sar("setsar"only)` โ set the aspect ratio used by the filter.
The parameter can be a floating point number string, or an expression. If the parameter isn't specified, the value "0" is assumed, which means the same input value is used. ๐ซถ
maxโ set the maximum integer value to use for expressing the numerator and denominator when reducing the expressed aspect ratio to a rational. Default value is100.
The sar parameter is an expression containing these constants:
w,hโ the input width and height.aโ same asw / h.sarโ the input sample aspect ratio.darโ the input display aspect ratio. Same as(w / h) * sar.hsub,vsubโ horizontal and vertical chroma subsample values. For example, for the pixel format"yuv422p",hsubis2andvsubis1.
๐ Examples
- To change the display aspect ratio to 16:9, specify one of the following:
setdar=dar=1.77777
setdar=dar=16/9
- To change the sample aspect ratio to 10:11, specify:
setsar=sar=10/11
- To set a display aspect ratio of 16:9 and specify a maximum integer value of
1000in the aspect ratio reduction, use the command:
setdar=ratio=16/9:max=1000
๐๏ธ setfield
Forces the field for the output video frame.
The "setfield" filter marks the interlace type field for the output frames. It doesn't change the input frame at all โ it only sets the corresponding property, which affects how the frame is treated by the following filters (e.g. "fieldorder" or "yadif"). โจ
The filter accepts the following options:
modeโ available values are:autoโ keep the same field property.bffโ mark the frame as bottom-field-first.tffโ mark the frame as top-field-first.progโ mark the frame as progressive.
๐จ setparams
Forces the frame parameter for the output video frame.
The "setparams" filter marks interlace and color range for the output frames. Again, it doesn't change the input frame โ it only sets the corresponding property, which affects how the frame is treated by filters/encoders. ๐ซ
field_modeโ available values are:autoโ keep the same field property (default).bffโ mark the frame as bottom-field-first.tffโ mark the frame as top-field-first.progโ mark the frame as progressive.
rangeโ available values are:autoโ keep the same color range property (default).unspecified,unknownโ mark the frame as unspecified color range.limited,tv,mpegโ mark the frame as limited range.full,pc,jpegโ mark the frame as full range.
color_primariesโ set the color primaries. Available values are:autoโ keep the same color primaries property (default).bt709unknownbt470mbt470bgsmpte170msmpte240mfilmbt2020smpte428smpte431smpte432jedec-p22
color_trcโ set the color transfer. Available values are:autoโ keep the same color trc property (default).bt709unknownbt470mbt470bgsmpte170msmpte240mlinearlog100log316iec61966-2-4bt1361eiec61966-2-1bt2020-10bt2020-12smpte2084smpte428arib-std-b67
colorspaceโ set the colorspace. Available values are:autoโ keep the same colorspace property (default).gbrbt709unknownfccbt470bgsmpte170msmpte240mycgcobt2020ncbt2020csmpte2085chroma-derived-ncchroma-derived-cictcp
chroma_locationโ set the chroma sample location. Available values are:autoโ keep the same chroma location (default).unspecified,unknownleftcentertoplefttopbottomleftbottom
alpha_modeโ set the alpha moda (yes, "moda" โ that's the manual's typo, it means mode ๐ญ). Available values are:autoโ keep the same alpha mode (default).unspecified,unknownpremultipliedstraight
๐ shear
Applies a shear transform to the input video. it's giving slanted.
This filter supports the following options:
shxโ shear factor in the X-direction. Default value is0. Allowed range is from-2to2.shyโ shear factor in the Y-direction. Default value is0. Allowed range is from-2to2.fillcolor,cโ set the color used to fill the output area not covered by the transformed video. For the general syntax of this option, check the"Color"section in theffmpeg-utilsmanual. If the special value"none"is selected, then no background is printed (useful, for example, if the background is never shown). Default value is"black". ๐คinterpโ set the interpolation type. Can be"bilinear"or"nearest". Default is"bilinear".
๐ Commands
This filter supports the all above options as commands. yup, all of them, live, mid-stream. slay.
๐ showinfo
Shows a line containing various information for each input video frame. The input video is not modified โ purely a vibe check, no touchy. ๐
This filter supports the following options:
checksumโ calculate checksums of each plane. Enabled by default.udu_sei_as_asciiโ try to print user data unregistered SEI as ascii characters when possible, in hex format otherwise.
The shown line contains a sequence of key/value pairs of the form key:value.
These values show up in the output:
nโ the (sequential) number of the input frame, starting from0.ptsโ the Presentation TimeStamp of the input frame, expressed as a number of time base units. The time base unit depends on the filter input pad.pts_timeโ the Presentation TimeStamp of the input frame, expressed as a number of seconds.fmtโ the pixel format name.sarโ the sample aspect ratio of the input frame, expressed in the formnum/den.sโ the size of the input frame, bestie. For the exact syntax of this one, go peek at the "Video size" section in theffmpeg-utilsmanual ๐iโ the type of interlaced mode. It's"P"for "progressive","T"for top field first,"B"for bottom field first ๐๏ธiskeyโ this is1if the frame is a key frame,0otherwise ๐typeโ the picture type of the input frame:"I"for an I-frame,"P"for a P-frame,"B"for a B-frame, or"?"for an unknown type. Also refer to the documentation of the"AVPictureType"enum and of the"av_get_picture_type_char"function defined inlibavutil/avutil.h๐checksumโ the Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame ๐งฎplane_checksumโ the Adler-32 checksum (printed in hexadecimal) of each plane of the input frame, expressed in the form"[c0 c1 c2 c3]"โจmeanโ the mean value of pixels in each plane of the input frame, expressed in the form"[mean0 mean1 mean2 mean3]"๐stdevโ the standard deviation of pixel values in each plane of the input frame, expressed in the form"[stdev0 stdev1 stdev2 stdev3]"๐
๐จ showpalette
Displays the 256 colors palette of each frame. Heads up though โ this filter is only relevant for pal8 pixel format frames, so if your frames aren't pal8 it's giving nothing, lowkey ๐
It accepts the following option:
sโ set the size of the box used to represent one palette color entry. Default is30(for a"30x30"pixel box) ๐ผ๏ธ
๐ shuffleframes
Reorder and/or duplicate and/or drop video frames. Chaos, but make it intentional ๐ซ
It accepts the following parameters:
mappingโ set the destination indexes of input frames. This is a space or'|'separated list of indexes that maps input frames to output frames. Number of indexes also sets maximal value that each index may have. The'-1'index has special meaning and that is to drop the frame ๐
The first frame has the index 0. The default is to keep the input unchanged.
Examples
- Swap second and third frame of every three frames of the input:
ffmpeg -i INPUT -vf "shuffleframes=0 2 1" OUTPUT
- Swap 10th and 1st frame of every ten frames of the input:
ffmpeg -i INPUT -vf "shuffleframes=9 1 2 3 4 5 6 7 8 0" OUTPUT
๐งฉ shufflepixels
Reorder pixels in video frames. Yes, actually. Pixel chaos, on purpose ๐ฆ
This filter accepts the following options:
direction,dโ set shuffle direction. Can beforwardorinversedirection. Default direction isforwardโฌ ๏ธโก๏ธmode,mโ set shuffle mode. Can behorizontal,verticalorblockmode ๐งฑwidth,wandheight,hโ set shuffleblock_size. In case of horizontal shuffle mode only thewidthpart of size is used, and in case of vertical shuffle mode only theheightpart of size is used ๐seed,sโ set random seed used with shuffling pixels. Mainly useful to set to be able to reverse the filtering process to get the original input back. For example, to reverse forward shuffle you need to use the same parameters and the exact same seed and to setdirectiontoinverse๐ฑ
๐ญ shuffleplanes
Reorder and/or duplicate video planes. Plane remix, no cap ๐
It accepts the following parameters:
map0โ the index of the input plane to be used as the first output plane.map1โ the index of the input plane to be used as the second output plane.map2โ the index of the input plane to be used as the third output plane.map3โ the index of the input plane to be used as the fourth output plane.
The first plane has the index 0. The default is to keep the input unchanged.
Examples
- Swap the second and third planes of the input:
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
๐ก signalstats
Evaluate various visual metrics that assist in determining issues associated with the digitization of analog video media. Basically a lil detective for your tape transfers ๐ต๏ธโโ๏ธ
By default the filter will log these metadata values:
YMINโ display the minimal Y value contained within the input frame. Expressed in range of[0-255].YLOWโ display the Y value at the 10% percentile within the input frame. Expressed in range of[0-255].YAVGโ display the average Y value within the input frame. Expressed in range of[0-255].YHIGHโ display the Y value at the 90% percentile within the input frame. Expressed in range of[0-255].YMAXโ display the maximum Y value contained within the input frame. Expressed in range of[0-255].UMINโ display the minimal U value contained within the input frame. Expressed in range of[0-255].ULOWโ display the U value at the 10% percentile within the input frame. Expressed in range of[0-255].UAVGโ display the average U value within the input frame. Expressed in range of[0-255].UHIGHโ display the U value at the 90% percentile within the input frame. Expressed in range of[0-255].UMAXโ display the maximum U value contained within the input frame. Expressed in range of[0-255].VMINโ display the minimal V value contained within the input frame. Expressed in range of[0-255].VLOWโ display the V value at the 10% percentile within the input frame. Expressed in range of[0-255].VAVGโ display the average V value within the input frame. Expressed in range of[0-255].VHIGHโ display the V value at the 90% percentile within the input frame. Expressed in range of[0-255].VMAXโ display the maximum V value contained within the input frame. Expressed in range of[0-255].SATMINโ display the minimal saturation value contained within the input frame. Expressed in range of[0-~181.02].SATLOWโ display the saturation value at the 10% percentile within the input frame. Expressed in range of[0-~181.02].SATAVGโ display the average saturation value within the input frame. Expressed in range of[0-~181.02].SATHIGHโ display the saturation value at the 90% percentile within the input frame. Expressed in range of[0-~181.02].SATMAXโ display the maximum saturation value contained within the input frame. Expressed in range of[0-~181.02].HUEMEDโ display the median value for hue within the input frame. Expressed in range of[0-360].HUEAVGโ display the average value for hue within the input frame. Expressed in range of[0-360].YDIFโ display the average of sample value difference between all values of the Y plane in the current frame and corresponding values of the previous input frame. Expressed in range of[0-255].UDIFโ display the average of sample value difference between all values of the U plane in the current frame and corresponding values of the previous input frame. Expressed in range of[0-255].VDIFโ display the average of sample value difference between all values of the V plane in the current frame and corresponding values of the previous input frame. Expressed in range of[0-255].YBITDEPTHโ display bit depth of Y plane in current frame. Expressed in range of[0-16].UBITDEPTHโ display bit depth of U plane in current frame. Expressed in range of[0-16].VBITDEPTHโ display bit depth of V plane in current frame. Expressed in range of[0-16].
The filter accepts the following options:
stat,outโ specify an additional form of image analysis.outoutputs video with the specified type of pixel highlighted โจ
Both options accept the following values:
toutโ identify temporal outliers pixels. A temporal outlier is a pixel unlike the neighboring pixels of the same field. Examples of temporal outliers include the results of video dropouts, head clogs, or tape tracking issues ๐vrepโ identify vertical line repetition. Vertical line repetition includes similar rows of pixels within a frame. In born-digital video vertical line repetition is common, but this pattern is uncommon in video digitized from an analog source. When it occurs in video that results from the digitization of an analog source it can indicate concealment from a dropout compensator ๐brngโ identify pixels that fall outside of legal broadcast range ๐จcolor,cโ set the highlight color for theoutoption. The default color isyellow๐
Examples
- Output data of various video metrics:
ffprobe -f lavfi movie=example.mov,signalstats="stat=tout+vrep+brng" -show_frames
- Output specific data about the minimum and maximum values of the Y plane per frame:
ffprobe -f lavfi movie=example.mov,signalstats -show_entries frame_tags=lavfi.signalstats.YMAX,lavfi.signalstats.YMIN
- Playback video while highlighting pixels that are outside of broadcast range in red:
ffplay example.mov -vf signalstats="out=brng:color=red"
- Playback video with signalstats metadata drawn over the frame:
ffplay example.mov -vf signalstats=stat=brng+vrep+tout,drawtext=fontfile=FreeSerif.ttf:textfile=signalstat_drawtext.txt
The contents of signalstat_drawtext.txt used in the command are:
time %{pts:hms}
Y (%{metadata:lavfi.signalstats.YMIN}-%{metadata:lavfi.signalstats.YMAX})
U (%{metadata:lavfi.signalstats.UMIN}-%{metadata:lavfi.signalstats.UMAX})
V (%{metadata:lavfi.signalstats.VMIN}-%{metadata:lavfi.signalstats.VMAX})
saturation maximum: %{metadata:lavfi.signalstats.SATMAX}
๐๏ธ signature
Calculates the MPEG-7 Video Signature. The filter can handle more than one input. In this case the matching between the inputs can be calculated additionally. The filter always passes through the first input. The signature of each stream can be written into a file. Very main character of it, honestly ๐
It accepts the following options:
detectmodeโ enable or disable the matching process ๐
Available values are:
offโ disable the calculation of a matching (default) ๐ซfullโ calculate the matching for the whole video and output whether the whole video matches or only parts ๐ฏfastโ calculate only until a matching is found or the video ends. Should be faster in some cases โกnb_inputsโ set the number of inputs. The option value must be a non negative integer. Default value is1๐ขfilenameโ sets the path where the output gets written. Okay so real talk: if you've got more than one input, this path has to be a prototype, meaning it must contain%dor%0nd(where n is a positive integer) โ that's the slot the input number gets swapped into. And if you don't specify a filename at all? Nothing gets written. That's the default, babes. ๐formatโ picks the output format. Your options are:binaryโ use the specified binary representation (this is the default, so it's giving lowkey reliable ๐).xmlโ use the specified xml representation.
th_dโ sets the threshold for detecting one word as similar. Value has to be an integer greater than zero. Default is9000. โจth_dcโ sets the threshold for detecting all words as similar. Integer greater than zero, bestie. Default is60000.th_xhโ sets the threshold for detecting frames as similar. Integer greater than zero. Default is116.th_diโ sets the minimum length of a sequence, in frames, for it to count as a matching sequence. Gotta be a non-negative integer value. Default is0. ๐ฆth_itโ sets the minimum relation that matching frames to all frames must have. The value must be a double between 0 and 1. Default is0.5. ๐ธ
Examples ๐
- Wanna calculate the signature of an input video and stash it in
signature.bin? Say less:
ffmpeg -i input.mkv -vf signature=filename=signature.bin -map 0:v -f null -
- Wanna detect whether two videos match and store the signatures in XML format in
signature0.xmlandsignature1.xml? Iconic, do this:
ffmpeg -i input1.mkv -i input2.mkv -filter_complex "[0:v][1:v] signature=nb_inputs=2:detectmode=full:format=xml:filename=signature%d.xml" -map :v -f null -
๐ง siti ๐ง
Calculates Spatial Information (SI) and Temporal Information (TI) scores for a video, as defined in ITU-T Rec. P.910 (11/21): Subjective video quality assessment methods for multimedia applications. The PDF lives at <https://www.itu.int/rec/T-REC-P.910-202111-S/en> if you wanna read the whole thing (respect if you do, ngl).
Heads up bestie โ this is a legacy implementation that corresponds to a superseded recommendation. If you want the latest and greatest, refer to ITU-T Rec. P.910 (07/22): <https://www.itu.int/rec/T-REC-P.910-202207-I/en> ๐
It accepts the following option:
print_summaryโ if set to1, summary statistics get printed to the console. Default is0.
Examples โจ
- To calculate SI/TI metrics and print summary:
ffmpeg -i input.mp4 -vf siti=print_summary=1 -f null -
๐ smartblur ๐
Blurs the input video without impacting the outlines. The way it keeps your edges crisp while smoothing everything else? Obsessed. ๐ญ
It accepts the following options:
luma_radius,lrโ sets the luma radius. Value must be a float in the range[0.1,5.0]that specifies the variance of the gaussian filter used to blur the image (slower if larger, obviously). Default is1.0.luma_strength,lsโ sets the luma strength. Float in the range[-1.0,1.0]that configures the blurring. A value in[0.0,1.0]will blur the image, whereas a value in[-1.0,0.0]will sharpen it. Default is1.0.luma_threshold,ltโ sets the luma threshold used as a coefficient to decide whether a pixel should be blurred or not. Integer in the range[-30,30]. A value of0filters all the image, a value in[0,30]filters flat areas, and a value in[-30,0]filters edges. Default is0.chroma_radius,crโ sets the chroma radius. Float in[0.1,5.0], same gaussian-variance situation (slower if larger). Default value isluma_radiusโ it literally inherits, cute ๐.chroma_strength,csโ sets the chroma strength. Float in[-1.0,1.0]. Blurs in[0.0,1.0], sharpens in[-1.0,0.0]. Default value isluma_strength.chroma_threshold,ctโ sets the chroma threshold coefficient for the blur-or-not decision. Integer in[-30,30]:0filters all the image,[0,30]filters flat areas,[-30,0]filters edges. Default value isluma_threshold.alpha_radius,arโ sets the alpha radius. Float in[0.1,5.0], gaussian variance again (slower if larger). Default value isluma_radius.alpha_strength,asโ sets the alpha strength. Float in[-1.0,1.0]. Blur in[0.0,1.0], sharpen in[-1.0,0.0]. Default value isluma_strength.alpha_threshold,atโ sets the alpha threshold coefficient for the blur-or-not decision. Integer in[-30,30]:0filters all the image,[0,30]filters flat areas,[-30,0]filters edges. Default value isluma_threshold.
If a chroma or alpha option is not explicitly set, the corresponding luma value gets used instead. So like, set nothing and everything just vibes off luma. ๐
โญ sobel โญ
Applies the sobel operator to the input video stream. Edge detection goes brrr.
The filter accepts the following option:
planesโ sets which planes get processed; unprocessed planes are copied over untouched. Default value0xfmeans all planes get processed.scaleโ sets the value that gets multiplied with the filtered result.deltaโ sets the value that gets added to the filtered result.
Commands ๐ซถ
This filter supports the all above options as commands. (Yes, all of them, periodt.)
๐ spp ๐
Applies a simple postprocessing filter that compresses and decompresses the image at several (or โ in the case of quality level 6 โ all) shifts, then averages the results. It's giving "brute force but make it fashion". ๐
The filter accepts the following options:
qualityโ sets quality. This option defines the number of levels for averaging. Accepts an integer in the range0-6. If set to0, the filter has no effect at all. A value of6means the higher quality. For each increment of that value, the speed drops by a factor of approximately2. Default value is3. ๐ญ the math is mathingqpโ force a constant quantization parameter. If not set, the filter will use the QP from the video stream (if available).modeโ sets the thresholding mode. Available modes are:hardโ set hard thresholding (default).softโ set soft thresholding (better de-ringing effect, but likely blurrier).
use_bframe_qpโ enables the use of the QP from the B-Frames if set to1. Careful bestie โ using this option may cause flicker, since the B-Frames often have larger QP. Default is0(not enabled). ๐
Commands ๐
This filter supports the following commands:
quality,levelโ sets the quality level. The value"max"can be used to set the maximum level, currently6.
๐ฆ sr ๐ฆ
Scales the input by applying one of the super-resolution methods based on convolutional neural networks. Supported models:
- Super-Resolution Convolutional Neural Network model (SRCNN). See <https://arxiv.org/abs/1501.00092>.
- Efficient Sub-Pixel Convolutional Neural Network model (ESPCN). See <https://arxiv.org/abs/1609.05158>.
Training scripts as well as scripts for model file (.pb) saving can be found at <https://github.com/XueweiMeng/sr/tree/sr_dnn_native>. Original repository is at <https://github.com/HighVoltageRocknRoll/sr.git>. Go give 'em a star, they earned it ๐
The filter accepts the following options:
dnn_backendโ specifies which DNN backend to use for model loading and execution. Accepts the following values:tensorflowโ TensorFlow backend. To enable this backend you need to install the TensorFlow for C library (see <https://www.tensorflow.org/install/lang_c>) and configure FFmpeg with--enable-libtensorflow. No cap, you actually have to do both. ๐ฅ
modelโ sets the path to the model file specifying the network architecture and its parameters. Note that different backends use different file formats. TensorFlow and OpenVINO backend can load files for only its format.scale_factorโ sets the scale factor for the SRCNN model. Allowed values are2,3and4. Default value is2. The scale factor is necessary for the SRCNN model because it accepts input upscaled using bicubic upscaling with the proper scale factor. โจ
Want full functionality (such as async execution)? Please use the dnn_processing filter instead. iykyk ๐
๐ sr_amf ๐
Upscales (size increasing) the input video using the AMD Advanced Media Framework library for hardware acceleration. Uses advanced algorithms for upscaling with higher output quality. Setting the output width and height works in the same way as for the scale filter โ so if you already know that one, you're chillin'. ๐ง
The filter accepts the following options:
w,hโ set the output video dimension expression. Default value is the input dimension. Allows for the same expressions as thescalefilter.algorithmโ sets the algorithm used for scaling:bilinearโ Bilinearbicubicโ Bicubicsr1-0โ Video SR1.0. This is a default value ๐pointโ Pointsr1-1โ Video SR1.1
sharpnessโ controls hq scaler sharpening. The value is a float in the range of[0.0, 2.0].formatโ controls the output pixel format. By default, or if none is specified, the input pixel format is used.keep-ratioโ forces the scaler to keep the aspect ratio of the input image when the output size has a different aspect ratio. Default value isfalse. Bestie do NOT let your video get squished ๐ญfillโ specifies whether the output image outside the region of interest, which doesn't fill the entire output surface, should be filled with a solid color.
Examples ๐ธ
- Scale input to 720p, keeping aspect ratio and ensuring the output is
yuv420p:
sr_amf=-2:720:format=yuv420p
- Upscale to 4K with algorithm video SR1.1:
sr_amf=4096:2160:algorithm=sr1-1
๐ ssim ๐
Obtains the SSIM (Structural SImilarity Metric) between two input videos. Comparison girlie behavior fr fr.
This filter takes in input two input videos; the first input is considered the "main" source and is passed unchanged to the output. The second input is used as a "reference" video for computing the SSIM.
Okay bestie, so both video inputs have got to match on resolution AND pixel format or this filter simply will not do its thing ๐ . It also lowkey assumes both inputs have the same number of frames, and it compares them one by one.
The filter stores the calculated SSIM of each frame.
Here's what the accepted parameters look like:
stats_file,fโ if you set this, the filter uses the named file to save the SSIM of each individual frame. And when the filename equals-, the data gets sent to standard output. ๐ซถ
The file printed when stats_file is selected contains a sequence of key:value pairs, one of the form key:value for each compared couple of frames.
A description of each shown parameter follows:
nโ sequential number of the input frame, starting from1.Y,U,V,R,G,Bโ SSIM of the compared frames for the component specified by the suffix.Allโ SSIM of the compared frames for the whole frame.dBโ same as above but in dB representation.
This filter also supports the framesync options.
โจ Examples
- For example:
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
[main][ref] ssim="stats_file=stats.log" [out]
On this example the input file being processed is compared with the reference file ref_movie.mpg. The SSIM of each individual frame is stored in stats.log.
- Another example with both
psnrandssimat same time:
ffmpeg -i main.mpg -i ref.mpg -lavfi "ssim;[0:v][1:v]psnr" -f null -
- Another example with different containers:
ffmpeg -i main.mpg -i ref.mkv -lavfi "[0:v]settb=AVTB,setpts=PTS-STARTPTS[main];[1:v]settb=AVTB,setpts=PTS-STARTPTS[ref];[main][ref]ssim" -f null -
๐ถ๏ธ stereo3d
Convert between different stereoscopic image formats. Literally 3D glasses energy, we love to see it ๐.
The filters accept the following options:
inโ Set stereoscopic image format of input.
Available values for input image formats are:
sbslโ side by side parallel (left eye left, right eye right)sbsrโ side by side crosseye (right eye left, left eye right)sbs2lโ side by side parallel with half width resolution (left eye left, right eye right)sbs2rโ side by side crosseye with half width resolution (right eye left, left eye right)abl,tblโ above-below (left eye above, right eye below)abr,tbrโ above-below (right eye above, left eye below)ab2l,tb2lโ above-below with half height resolution (left eye above, right eye below)ab2r,tb2rโ above-below with half height resolution (right eye above, left eye below)alโ alternating frames (left eye first, right eye second)arโ alternating frames (right eye first, left eye second)irlโ interleaved rows (left eye has top row, right eye starts on next row)irrโ interleaved rows (right eye has top row, left eye starts on next row)iclโ interleaved columns, left eye firsticrโ interleaved columns, right eye first
Default value is sbsl.
outโ Set stereoscopic image format of output.sbslโ side by side parallel (left eye left, right eye right)sbsrโ side by side crosseye (right eye left, left eye right)sbs2lโ side by side parallel with half width resolution (left eye left, right eye right)sbs2rโ side by side crosseye with half width resolution (right eye left, left eye right)abl,tblโ above-below (left eye above, right eye below)abr,tbrโ above-below (right eye above, left eye below)ab2l,tb2lโ above-below with half height resolution (left eye above, right eye below)ab2r,tb2rโ above-below with half height resolution (right eye above, left eye below)alโ alternating frames (left eye first, right eye second)arโ alternating frames (right eye first, left eye second)irlโ interleaved rows (left eye has top row, right eye starts on next row)irrโ interleaved rows (right eye has top row, left eye starts on next row)arbgโ anaglyph red/blue gray (red filter on left eye, blue filter on right eye)arggโ anaglyph red/green gray (red filter on left eye, green filter on right eye)arcgโ anaglyph red/cyan gray (red filter on left eye, cyan filter on right eye)archโ anaglyph red/cyan half colored (red filter on left eye, cyan filter on right eye)arccโ anaglyph red/cyan color (red filter on left eye, cyan filter on right eye)arcdโ anaglyph red/cyan color optimized with the least squares projection of dubois (red filter on left eye, cyan filter on right eye)agmgโ anaglyph green/magenta gray (green filter on left eye, magenta filter on right eye)agmhโ anaglyph green/magenta half colored (green filter on left eye, magenta filter on right eye)agmcโ anaglyph green/magenta colored (green filter on left eye, magenta filter on right eye)agmdโ anaglyph green/magenta color optimized with the least squares projection of dubois (green filter on left eye, magenta filter on right eye)aybgโ anaglyph yellow/blue gray (yellow filter on left eye, blue filter on right eye)aybhโ anaglyph yellow/blue half colored (yellow filter on left eye, blue filter on right eye)aybcโ anaglyph yellow/blue colored (yellow filter on left eye, blue filter on right eye)aybdโ anaglyph yellow/blue color optimized with the least squares projection of dubois (yellow filter on left eye, blue filter on right eye)mlโ mono output (left eye only)mrโ mono output (right eye only)chlโ checkerboard, left eye firstchrโ checkerboard, right eye firsticlโ interleaved columns, left eye firsticrโ interleaved columns, right eye firsthdmiโ HDMI frame pack
Default value is arcd.
๐ Examples
- Convert input video from side by side parallel to anaglyph yellow/blue dubois:
stereo3d=sbsl:aybd
- Convert input video from above below (left eye above, right eye below) to side by side crosseye.
stereo3d=abl:sbsr
๐ streamselect, astreamselect
Select video or audio streams. Pick-your-fighter but for streams ๐
The filter accepts the following options:
inputsโ Set number of inputs. Default is2.mapโ Set input indexes to remap to outputs.
Commands
The streamselect and astreamselect filter supports the following commands:
mapโ Set input indexes to remap to outputs.
๐ธ Examples
- Select first
5seconds 1st stream and rest of time 2nd stream:
sendcmd='5.0 streamselect map 1',streamselect=inputs=2:map=0
- Same as above, but for audio:
asendcmd='5.0 astreamselect map 1',astreamselect=inputs=2:map=0
๐ฌ subtitles
Draw subtitles on top of input video using the libass library. The way this filter just pops your captions on screen, obsessed ๐.
To enable compilation of this filter you need to configure FFmpeg with --enable-libass. This filter also requires a build with libavcodec and libavformat to convert the passed subtitles file to ASS (Advanced Substation Alpha) subtitles format.
The filter accepts the following options:
filename,fโ Set the filename of the subtitle file to read. It must be specified.original_sizeโ Specify the size of the original video, the video for which the ASS file was composed. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. Due to a misdesign in ASS aspect ratio arithmetic, this is necessary to correctly scale the fonts if the aspect ratio has been changed.fontsdirโ Set a directory path containing fonts that can be used by the filter. These fonts will be used in addition to whatever the font provider uses.alphaโ Process alpha channel, by default alpha channel is untouched.charencโ Set subtitles input character encoding.subtitlesfilter only. Only useful if not UTF-8.stream_index,siโ Set subtitles stream index.subtitlesfilter only.force_styleโ Override default style or script info parameters of the subtitles. It accepts a string containing ASS style formatKEY=VALUEcouples separated by,.wrap_unicodeโ Break lines according to the Unicode Line Breaking Algorithm. Availability requires at least libass release0.17.0(orLIBASS_VERSION 0x01600010), and libass must have been built with libunibreak.
The option is enabled by default except for native ASS.
If the first key is not specified, it is assumed that the first value specifies the filename.
For example, to render the file sub.srt on top of the input video, use the command:
subtitles=sub.srt
which is equivalent to:
subtitles=filename=sub.srt
To render the default subtitles stream from file video.mkv, use:
subtitles=video.mkv
To render the second subtitles stream from that file, use:
subtitles=video.mkv:si=1
To make the subtitles stream from sub.srt appear in 80% transparent blue DejaVu Serif, use:
subtitles=sub.srt:force_style='Fontname=DejaVu Serif,PrimaryColour=&HCCFF0000'
๐ super2xsai
Scale the input by 2x and smooth using the Super2xSaI (Scale and Interpolate) pixel art scaling algorithm. Pixel art girlies stay winning ๐จโจ.
Useful for enlarging pixel art images without reducing sharpness.
๐ swaprect
Swap two rectangular objects in video. It's giving "trading places" but make it rectangles ๐ญ.
This filter accepts the following options:
wโ Set object width.hโ Set object height.x1โ Set 1st rect x coordinate.y1โ Set 1st rect y coordinate.x2โ Set 2nd rect x coordinate.y2โ Set 2nd rect y coordinate.
All expressions are evaluated once for each frame.
The all options are expressions containing the following constants:
w,hโ The input width and height.aโ same asw / hsarโ input sample aspect ratiodarโ input display aspect ratio, it is the same as(w / h) * sarnโ The number of the input frame, starting from0.tโ The timestamp expressed in seconds. It'sNANif the input timestamp is unknown.posโ the position in the file of the input frame,NANif unknown; deprecated, do not use
Commands
This filter supports the all above options as commands.
๐ swapuv
Swaps the U and V planes. That's it, that's the whole filter โ a little chroma flip, no cap. ๐
๐ tblend
Blends successive video frames together, one after another.
See blend for the full deets, bestie โ this one's just the simple cousin. โจ
๐ telecine
Applies the telecine process to your video. Iconic film-to-video pipeline behavior, lowkey.
It takes these options:
first_fieldโ picks which field comes first:top,tโ top field firstbottom,bโ bottom field first The default value istop.
patternโ a string of numbers representing the pulldown pattern you want to apply. The default value is23.
Some typical patterns, for the girlies who need a reference ๐:
NTSC output (30i):
- 27.5p:
32222 - 24p:
23(classic) - 24p:
2332(preferred) - 20p:
33 - 18p:
334 - 16p:
3444
PAL output (25i):
- 27.5p:
12222 - 24p:
222222222223("Euro pulldown") - 16.67p:
33 - 16p:
33333334
๐ thistogram
Computes AND draws a color distribution histogram for your input video โ across time. Obsessed with the temporal glow-up honestly ๐ฆ
Unlike the histogram video filter, which only shows the histogram of a single input frame at a certain time, this filter also shows past histograms for a number of frames defined by the width option. Basically it's the memories-having version of histogram, and we respect her for that.
The computed histogram is a representation of the color component distribution in an image.
It accepts these options:
width,wโ sets the width of a single color component output. Default value is0. A value of0means the width will be picked from the input video. This also sets the number of passed histograms to keep. Allowed range is[0, 8192].display_mode,dโ sets the display mode. Accepted values:stackโ per-color-component graphs are placed below each other.paradeโ per-color-component graphs are placed side by side.overlayโ presents information identical to that inparade, except that the graphs representing color components are superimposed directly over one another. Default isstack.
levels_mode,mโ sets the mode. Can be eitherlinearorlogarithmic. Default islinear.components,cโ sets what color components to display. Default is7.bgopacity,bโ sets the background opacity. Default is0.9.envelope,eโ show the envelope. Default is disabled.ecolor,ecโ sets the envelope color. Default isgold.slideโ sets the slide mode. Available values:frameโ draw a new frame when the right border is reached.replaceโ replace old columns with new ones.scrollโ scroll from right to left.rscrollโ scroll from left to right.pictureโ draw a single picture. Default isreplace.
๐ threshold
Applies a threshold effect to your video stream. Fr fr a whole little math moment ๐งฎ
This filter needs four video streams to do its thresholding:
- The first stream is the stream we're filtering.
- The second stream holds the threshold values.
- The third stream holds the min values.
- And the last, fourth stream holds the max values.
It accepts this option:
planesโ sets which planes will be processed; unprocessed planes get copied. By default the value is0xf, meaning all planes are processed.
So like, for example: if the first stream's pixel component value is less than the threshold value of the pixel component from the 2nd (threshold) stream, then the third stream value gets picked โ otherwise the fourth stream's pixel component value gets picked. Slay, conditional logic ๐
Using the color source filter, you can perform various types of thresholding:
๐ Commands
This filter supports all options as commands.
๐ Examples
- Binary threshold, using gray color as threshold:
ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=black -f lavfi -i color=white -lavfi threshold output.avi
- Inverted binary threshold, using gray color as threshold:
ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -f lavfi -i color=black -lavfi threshold output.avi
- Truncate binary threshold, using gray color as threshold:
ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=gray -lavfi threshold output.avi
- Threshold to zero, using gray color as threshold:
ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -i 320x240.avi -lavfi threshold output.avi
- Inverted threshold to zero, using gray color as threshold:
ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=white -lavfi threshold output.avi
๐ thumbnail
Selects the most representative frame out of a given sequence of consecutive frames. She's the group-photo editor of filters โ picks the one where everybody looks good ๐ธโจ
Options:
nโ sets the frames batch size to analyze. In a set ofnframes, the filter picks one of them, then handles the next batch ofnframes until the end. Default is100.logโ sets the log level to display picked frame stats. Default isinfo.
โ ๏ธ Heads up bestie: since the filter keeps track of the whole frames sequence, a biggernvalue means higher memory usage โ so a high value is not recommended. Don't be out here settingn=99999and then acting surprised, I'm begging ๐ญ
๐ Examples
- Extract one picture every 50 frames:
thumbnail=50
- Complete example of a thumbnail creation with
ffmpeg:
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
๐ tile
Tiles several successive frames together into one grid. Very collage, very mood board ๐
The untile filter can do the reverse โ iykyk.
Options:
layoutโ sets the grid size in the formCOLUMNSxROWS. Range is up toUINT_MAXcells. Default is6x5.nb_framesโ sets the maximum number of frames to render in the given area. It must be less than or equal towxh. Default value is0, meaning the whole area will be used.marginโ sets the outer border margin in pixels. Range is0to1024. Default is0.paddingโ sets the inner border thickness (i.e. the number of pixels between frames). For more advanced padding options (like different values for the edges), refer to thepadvideo filter. Range is0to1024. Default is0.colorโ specifies the color of the unused area. For the syntax of this option, check theColorsection in the ffmpeg-utils manual. The default value of color isblack.overlapโ sets the number of frames to overlap when tiling several successive frames together. The value must be between0andnb_frames - 1. Default is0.init_paddingโ sets the number of frames to initially be empty before displaying the first output frame. This controls how soon you get that first output frame. The value must be between0andnb_frames - 1. Default is0.
๐ Examples
- Produce 8x8 PNG tiles of all keyframes (
-skip_frame nokey) in a movie:
ffmpeg -skip_frame nokey -i file.avi -vf 'scale=128:72,tile=8x8' -an -vsync 0 keyframes%03d.png
The -vsync 0 is necessary to prevent ffmpeg from duplicating each output frame to accommodate the originally detected frame rate. Do not skip it, bestie, I'm serious ๐
- Display 5 pictures in an area of
3x2frames, with 7 pixels between them, and 2 pixels of initial margin, using mixed flat and named options:
tile=3x2:nb_frames=5:padding=7:margin=2
๐ tiltandshift
Applies a tilt-and-shift effect. Okay so this one is genuinely a philosophical moment, buckle up ๐
What happens when you invert time and space?
Normally a video is composed of several frames that represent a different instant of time and shows a scene that evolves in the space captured by the frame. This filter is the antipode of that concept โ it's taking inspiration from tilt and shift photography.
A filtered frame contains the whole timeline of events composing the sequence, and this is obtained by placing a slice of pixels from each frame into a single one. However โ since there are no infinite-width frames โ this is done up to the width of the input frame, and a video is recomposed by shifting away one column for each subsequent frame. In order to map space to time, the filter tilts each input frame as well, so that motion is preserved. This is accomplished by progressively selecting a different column from each input frame.
The end result is a sort of inverted parallax, so that far away objects move much faster than the ones in the front. The ideal conditions for this video effect are when there's either very little motion and the background is static, or when there's a lot of motion and a very wide depth of field (e.g. wide panorama, while moving on a train). ๐โจ
It accepts these parameters:
tiltโ tilt video while shifting (default). When unset, the video will be sliding a static image, composed of the first column of each frame.startโ what to do at the start of filtering (see below).endโ what to do at the end of filtering (see below).holdโ how many columns should pass through before start of filtering.padโ how many columns should be inserted before end of filtering.
Normally the filter shifts and tilts from the very first frame, and stops when the last one is received. However, before filtering starts, normal video may be preserved, so that the effect is slowly shifted into its place. Similarly, the last video frame may be reconstructed at the end. Alternatively, it's possible to just start and end with black.
noneโ filtering starts immediately and ends when the last frame is received.frameโ the first frames or the very last frame are kept intact during processing.blackโ black is padded at the beginning or at the end of filtering.
๐ tinterlace
Performs various types of temporal field interlacing. Retro TV energy, respectfully ๐ซถ
Frames are counted starting from 1, so the first input frame is considered odd.
Options:
modeโ specifies the mode of the interlacing. This option can also be specified as a value alone. See below for the list of values.
Available values:
merge,0โ move odd frames into the upper field, even into the lower field, generating a double height frame at half frame rate.
------> time
Input:
Frame 1 Frame 2 Frame 3 Frame 4
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
โฆaaaand the output for that one looks like:
11111 33333
22222 44444
11111 33333
22222 44444
11111 33333
22222 44444
11111 33333
22222 44444
drop_even, 1
Only outputs the odd frames, bestie โ even frames get yeeted, and you get a frame with unchanged height at half frame rate. ๐
------> time
Input:
Frame 1 Frame 2 Frame 3 Frame 4
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
Output:
11111 33333
11111 33333
11111 33333
11111 33333
drop_odd, 2
Opposite energy: only the even frames make it out, odd frames are dropped, frame height stays the same, half frame rate. ๐ฆ
------> time
Input:
Frame 1 Frame 2 Frame 3 Frame 4
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
Output:
22222 44444
22222 44444
22222 44444
22222 44444
pad, 3
Each frame gets expanded to full height, but alternating lines get padded with black โ so you get double height at the same input frame rate. ๐
------> time
Input:
Frame 1 Frame 2 Frame 3 Frame 4
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
Output:
11111 ..... 33333 .....
..... 22222 ..... 44444
11111 ..... 33333 .....
..... 22222 ..... 44444
11111 ..... 33333 .....
..... 22222 ..... 44444
11111 ..... 33333 .....
..... 22222 ..... 44444
interleave_top, 4
Takes the upper field from odd frames and interleaves it with the lower field from even frames โ unchanged height, half frame rate. ๐ง
------> time
Input:
Frame 1 Frame 2 Frame 3 Frame 4
11111<- 22222 33333<- 44444
11111 22222<- 33333 44444<-
11111<- 22222 33333<- 44444
11111 22222<- 33333 44444<-
Output:
11111 33333
22222 44444
11111 33333
22222 44444
interleave_bottom, 5
The flip side, literally: the lower field from odd frames gets interleaved with the upper field from even frames. Unchanged height, half frame rate. ๐ธ
------> time
Input:
Frame 1 Frame 2 Frame 3 Frame 4
11111 22222<- 33333 44444<-
11111<- 22222 33333<- 44444
11111 22222<- 33333 44444<-
11111<- 22222 33333<- 44444
Output:
22222 44444
11111 33333
22222 44444
11111 33333
interlacex2, 6
Double frame rate, unchanged height. New frames get inserted, each one holding the second temporal field from the previous input frame plus the first temporal field from the next input frame. This mode relies on the top_field_first flag, okay? It's for interlaced video displays with no field synchronisation. โญ
------> time
Input:
Frame 1 Frame 2 Frame 3 Frame 4
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
Output:
11111 22222 22222 33333 33333 44444 44444
11111 11111 22222 22222 33333 33333 44444
11111 22222 22222 33333 33333 44444 44444
11111 11111 22222 22222 33333 33333 44444
mergex2, 7
Odd frames get moved into the upper field, even ones into the lower field โ so you get a double height frame at the same frame rate. ๐
------> time
Input:
Frame 1 Frame 2 Frame 3 Frame 4
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
11111 22222 33333 44444
Output:
11111 33333 33333 55555
22222 22222 44444 44444
11111 33333 33333 55555
22222 22222 44444 44444
11111 33333 33333 55555
22222 22222 44444 44444
11111 33333 33333 55555
22222 22222 44444 44444
Heads up bestie: numeric values are deprecated but still accepted for backward compatibility reasons. ๐
Default mode is merge. ๐
flags
Set flags that influence the filter process. โจ
Available value for flags is:
low_pass_filter,vlpfโ enables linear vertical low-pass filtering in the filter. You need vertical low-pass filtering when you're making an interlaced destination from a progressive source that's got high-frequency vertical detail. The filtering reduces interlace 'twitter' and Moire patterning. ๐complex_filter,cvlpfโ enables complex vertical low-pass filtering. This slightly less reduces interlace 'twitter' and Moire patterning, but keeps detail and that subjective sharpness impression better. ๐ฅbypass_ilโ bypasses already interlaced frames, and only adjusts the frame rate.
Real talk: vertical low-pass filtering and bypassing already interlaced frames can only be enabled for modeinterleave_topandinterleave_bottom. ๐ญ
๐ tmedian
Picks median pixels out of several successive input video frames. Iconic little filter ngl.
The filter accepts the following options:
radiusโ sets the radius of the median filter. Default is1. Allowed range is from1to127.planesโ sets which planes to filter. Default value is15, and by that all planes are processed.percentileโ sets the median percentile. Default value is0.5. The default0.5will always pick median values, while0picks minimum values, and1picks maximum values.
Commands
This filter supports all the above options as commands, excluding the option radius. ๐
๐ tmidequalizer
Applies the Temporal Midway Video Equalization effect. ๐ฆ
Midway Video Equalization adjusts a sequence of video frames so they all have the same histograms, while keeping their dynamics as much as possible. It's useful for stuff like matching exposures from a video frames sequence.
This filter accepts the following option:
radiusโ sets the filtering radius. Default is5. Allowed range is from1to127.sigmaโ sets the filtering sigma. Default is0.5. This controls the strength of filtering. Setting this option to0effectively does nothing. ๐planesโ sets which planes to process. Default is15, which is all available planes.
๐ tmix
Mixes successive video frames. It's giving temporal blender energy fr fr.
A description of the accepted options follows.
framesโ the number of successive frames to mix. If unspecified, it defaults to3.weightsโ specifies the weight of each input video frame. Each weight is separated by space. If the number of weights is smaller than the number of frames, the last specified weight gets used for all the remaining unset weights.scaleโ specifies the scale. If it's set, it gets multiplied with the sum of each weight multiplied with pixel values to give the final destination pixel value. By default,scaleis auto scaled to the sum of the weights.planesโ sets which planes to filter. Default is all. Allowed range is from0to15.
Examples
- Average 7 successive frames:
tmix=frames=7:weights="1 1 1 1 1 1 1"
- Apply simple temporal convolution:
tmix=frames=3:weights="-1 3 -1"
- Similar as above but only showing temporal differences:
tmix=frames=3:weights="-1 2 -1":scale=1
Commands
This filter supports the following commands:
weightsscaleplanes
Syntax is the same as the option with the same name. ๐ซถ
๐ tonemap
okay so this one's a whole vibe remapper โ it tone maps colors from different dynamic ranges ๐
Real talk: this filter expects data in single precision floating point, because it literally needs to operate on (and can output) out-of-range values. So you can't just feed it whatever โ you need another filter, like zscale, to convert the resulting frame back into a usable format. It's giving "I do my job, you handle the cleanup" energy ๐ญ
Also โ the tonemapping algorithms implemented here only work on linear light, so your input data should be linearized beforehand (and possibly correctly tagged, bestie, don't skip that part).
ffmpeg -i INPUT -vf zscale=transfer=linear,tonemap=clip,zscale=transfer=bt709,format=yuv420p OUTPUT
Options
The filter accepts the following options. ๐
tonemapโ Set the tone map algorithm to use. Possible values are:noneโ Do not apply any tone map, only desaturate overbright pixels.clipโ Hard-clip any out-of-range values. Use it for perfect color accuracy for in-range values, while distorting out-of-range values.linearโ Stretch the entire reference gamut to a linear multiple of the display.gammaโ Fit a logarithmic transfer between the tone curves.reinhardโ Preserve overall image brightness with a simple curve, using nonlinear contrast, which results in flattening details and degrading color accuracy.hableโ Preserve both dark and bright details better thanreinhard, at the cost of slightly darkening everything. Use it when detail preservation is more important than color and brightness accuracy.mobiusโ Smoothly map out-of-range values, while retaining contrast and colors for in-range material as much as possible. Use it when color accuracy is more important than detail preservation.
Default is none. โจ
paramโ Tune the tone mapping algorithm.
This affects the following algorithms:
noneโ Ignored. (ngl it does nothing, bestie)linearโ Specifies the scale factor to use while stretching. Default to1.0.gammaโ Specifies the exponent of the function. Default to1.8.clipโ Specify an extra linear coefficient to multiply into the signal before clipping. Default to1.0.reinhardโ Specify the local contrast coefficient at the display peak. Default to0.5, which means that in-gamut values will be about half as bright as when clipping.hableโ Ignored.mobiusโ Specify the transition point from linear to mobius transform. Every value below this point is guaranteed to be mapped 1:1. The higher the value, the more accurate the result will be, at the cost of losing bright details. Default to0.3, which due to the steep initial slope still preserves in-range colors fairly accurately.
desatโ Apply desaturation for highlights that exceed this level of brightness. The higher the parameter, the more color information will be preserved. This setting helps prevent unnaturally blown-out colors for super-highlights, by (smoothly) turning into white instead. This makes images feel more natural, at the cost of reducing information about out-of-range colors.
The default of 2.0 is somewhat conservative and will mostly just apply to skies or directly sunlit surfaces. A setting of 0.0 disables this option.
Heads up ๐ซถ โ this option works only if the input frame has a supported color tag.
peakโ Override signal/nominal/reference peak with this value. Useful when the embedded peak information in display metadata is not reliable or when tone mapping from a lower range to a higher range.
๐ฆ tpad
Temporarily pad video frames. Like, literally add blank frames at the start or end. Iconic for syncing things up ๐
The filter accepts the following options:
startโ Specify number of delay frames before input video stream. Default is0.stopโ Specify number of padding frames after input video stream. Set to-1to pad indefinitely. Default is0.start_modeโ Set kind of frames added to beginning of stream. Can be eitheraddorclone. Withaddframes of solid-color are added. Withcloneframes are clones of first frame. Default isadd.stop_modeโ Set kind of frames added to end of stream. Can be eitheraddorclone. Withaddframes of solid-color are added. Withcloneframes are clones of last frame. Default isadd.start_duration,stop_durationโ Specify the duration of the start/stop delay. See the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. These options overridestartandstop. Default is0.colorโ Specify the color of the padded area. For the syntax of this option, check the"Color"section in theffmpeg-utilsmanual.
The default value of color is "black".
๐ transpose
Transpose rows with columns in the input video and optionally flip it. It's the "turn your video sideways" filter, and yes it does exactly what it says ๐ฅ
It accepts the following parameters:
dirโ Specify the transposition direction.
Can assume the following values:
0,4,cclock_flipโ Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
L.R L.l
. . -> . .
l.r R.r
1,5,clockโ Rotate by 90 degrees clockwise, that is:
L.R l.L
. . -> . .
l.r r.R
2,6,cclockโ Rotate by 90 degrees counterclockwise, that is:
L.R R.r
. . -> . .
l.r L.l
3,7,clock_flipโ Rotate by 90 degrees clockwise and vertically flip, that is:
L.R r.R
. . -> . .
l.r l.L
For values between 4-7, the transposition is only done if the input video geometry is portrait and not landscape. These values are deprecated, the "passthrough" option should be used instead. (fr fr, don't use them)
Numerical values are deprecated too, and should be dropped in favor of symbolic constants. ๐
passthroughโ Do not apply the transposition if the input geometry matches the one specified by the specified value. It accepts the following values:noneโ Always apply transposition.portraitโ Preserve portrait geometry (whenheight >= width).landscapeโ Preserve landscape geometry (whenwidth >= height).
Default value is "none".
For example to rotate by 90 degrees clockwise and preserve portrait layout:
transpose=dir=1:passthrough=portrait
The command above can also be specified as:
transpose=1:portrait
โจ trim
Trim the input so that the output contains one continuous subpart of the input. It's giving "cut to the good part" ๐
It accepts the following parameters:
startโ Specify the time of the start of the kept section, i.e. the frame with the timestamp start will be the first frame in the output.endโ Specify the time of the first frame that will be dropped, i.e. the frame immediately preceding the one with the timestamp end will be the last frame in the output.start_ptsโ This is the same asstart, except this option sets the start timestamp in timebase units instead of seconds.end_ptsโ This is the same asend, except this option sets the end timestamp in timebase units instead of seconds.durationโ The maximum duration of the output in seconds.start_frameโ The number of the first frame that should be passed to the output.end_frameโ The number of the first frame that should be dropped.
start, end, and duration are expressed as time duration specifications; see the Time duration section in the ffmpeg-utils(1) manual for the accepted syntax.
Bestie, listen ๐ โ note that the first two sets of the start/end options and thedurationoption look at the frame timestamp, while the_framevariants simply count the frames that pass through the filter. Also note that this filter does not modify the timestamps. If you wish for the output timestamps to start at zero, insert asetptsfilter after thetrimfilter. iykyk.
If multiple start or end options are set, this filter tries to be greedy and keep all the frames that match at least one of the specified constraints. To keep only the part that matches all the constraints at once, chain multiple trim filters.
The defaults are such that all the input is kept. So it is possible to set e.g. just the end values to keep everything before the specified time. ๐ซถ
Examples:
- Drop everything except the second minute of input:
ffmpeg -i INPUT -vf trim=60:120
- Keep only the first second:
ffmpeg -i INPUT -vf trim=duration=1
๐ unpremultiply
Apply alpha unpremultiply effect to input video stream using first plane of second stream as alpha.
Both streams must have same dimensions and same pixel format. No exceptions, sorry ๐ญ
The filter accepts the following option:
planesโ Set which planes will be processed, unprocessed planes will be copied. By default value0xf, all planes will be processed.
If the format has 1 or 2 components, then luma is bit 0. If the format has 3 or 4 components: for RGB formats bit 0 is green, bit 1 is blue and bit 2 is red; for YUV formats bit 0 is luma, bit 1 is chroma-U and bit 2 is chroma-V. If present, the alpha channel is always the last bit.
inplaceโ Do not require 2nd input for processing, instead use alpha plane from input stream.
๐ธ unsharp
Sharpen or blur the input video. Yes bestie, one filter, both directions โ it's versatile like that ๐
It accepts the following parameters:
luma_msize_x,lxโ Set the luma matrix horizontal size. It must be an odd integer between3and23. The default value is5.luma_msize_y,lyโ Set the luma matrix vertical size. It must be an odd integer between3and23. The default value is5.luma_amount,laโ Set the luma effect strength. It must be a floating point number, reasonable values lay between-1.5and1.5.
Negative values will blur the input video, while positive values will sharpen it, a value of zero will disable the effect.
Default value is 1.0.
chroma_msize_x,cxโ Set the chroma matrix horizontal size. It must be an odd integer between3and23. The default value is5.chroma_msize_y,cyโ Set the chroma matrix vertical size. It must be an odd integer between3and23. The default value is5.chroma_amount,caโ Set the chroma effect strength. It must be a floating point number, reasonable values lay between-1.5and1.5.alpha_msize_x,axโ sets the alpha matrix horizontal size ๐ it has to be an odd integer between 3 and 23, and the default is5.alpha_msize_y,ayโ same deal but vertical: odd integer between 3 and 23, default5.alpha_amount,aaโ the alpha effect strength, a floating point number, and the reasonable zone is between -1.5 and 1.5.
Negative values will blur the input video, while positive values will sharpen it โ a value of zero will disable the effect. โจ
Default value is 0.0.
All parameters are optional and default to the equivalent of the string '5:5:1.0:5:5:0.0'.
Examples ๐
- Apply strong luma sharpen effect:
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
- Apply a strong blur of both luma and chroma parameters:
unsharp=7:7:-2:7:7:-2
untile
Decomposes a video made of tiled images back into the individual images ๐ฆ it's literally the un-tiling of it all.
The frame rate of the output video is the frame rate of the input video multiplied by the number of tiles. math! iconic.
This filter does the reverse of tile.
The filter accepts the following options:
layoutโ sets the grid size (i.e. the number of lines and columns). For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. ๐
Examples ๐ธ
- Produce a 1-second video from a still image file made of 25 frames stacked vertically, like an analogic film reel:
ffmpeg -r 1 -i image.jpg -vf untile=1x25 movie.mkv
uspp
Applies the ultra slow/simple postprocessing filter that compresses and decompresses the image at several (or โ in the case of quality level 8 โ all) shifts and averages the results ๐
The way this differs from the behavior of spp is that uspp actually encodes & decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8 DCT similar to MJPEG. no cap, different machinery fr fr.
Heads up bestie ๐ This filter is not available in ffmpeg versions between 5.0 and 6.0. like it just dipped for a bit.
The filter accepts the following options:
qualityโ sets quality. This option defines the number of levels for averaging. It accepts an integer in the range 0-8. If set to 0, the filter will have no effect. A value of 8 means the higher quality ๐ฅ For each increment of that value the speed drops by a factor of approximately 2. Default value is3.qpโ force a constant quantization parameter. If not set, the filter will use the QP from the video stream (if available).codecโ use specified codec instead ofsnow.
v360
Converts 360 videos between various formats ๐ like a glow-up but for projections.
The filter accepts the following options:
input,outputโ set the format of the input/output video.
Available formats:
e,equirectโ equirectangular projection.c3x2,c6x1,c1x6โ cubemap with 3x2/6x1/1x6 layout.- Format specific options:
in_pad,out_padโ set padding proportion for the input/output cubemap. Values in decimals. Example values:0โ no padding.0.01โ 1% of face is padding. For example, with 1920x1280 resolution face size would be 640x640 and padding would be 3 pixels from each side. (640 * 0.01 = 6 pixels) Default value is0. Maximum value is0.1.
fin_pad,fout_padโ set fixed padding for the input/output cubemap. Values in pixels. Default value is0. If greater than zero it overrides other padding options.in_forder,out_forderโ set order of faces for the input/output cubemap. Choose one direction for each position. Designation of directions:rโ rightlโ leftuโ updโ downfโ forwardbโ back Default value isrludfb.
in_frot,out_frotโ set rotation of faces for the input/output cubemap. Choose one angle for each position. Designation of angles:0โ 0 degrees clockwise1โ 90 degrees clockwise2โ 180 degrees clockwise3โ 270 degrees clockwise Default value is000000.
eacโ Equi-Angular Cubemap.flat,gnomonic,rectilinearโ regular video.- Format specific options:
h_fov,v_fov,d_fovโ set output horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.ih_fov,iv_fov,id_fovโ set input horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.
dfisheyeโ dual fisheye.- Format specific options:
h_fov,v_fov,d_fovโ set output horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.ih_fov,iv_fov,id_fovโ set input horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.
barrel,fb,barrelsplitโ Facebook's 360 formats.sgโ stereographic format.- Format specific options:
h_fov,v_fov,d_fovโ set output horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.ih_fov,iv_fov,id_fovโ set input horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.
mercatorโ Mercator format.ballโ Ball format, gives significant distortion toward the back.hammerโ Hammer-Aitoff map projection format.sinusoidalโ Sinusoidal map projection format.fisheyeโ fisheye projection.- Format specific options:
h_fov,v_fov,d_fovโ set output horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.ih_fov,iv_fov,id_fovโ set input horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.
panniniโ Pannini projection.- Format specific options:
h_fovโ set output pannini parameter.ih_fovโ set input pannini parameter.
cylindricalโ cylindrical projection.- Format specific options:
h_fov,v_fov,d_fovโ set output horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.ih_fov,iv_fov,id_fovโ set input horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.
perspectiveโ perspective projection. (output only ๐)- Format specific options:
v_fovโ set perspective parameter.
tetrahedronโ Tetrahedron projection.tspโ Truncated square pyramid projection.he,hequirectโ half equirectangular projection.equisolidโ equisolid format.- Format specific options:
h_fov,v_fov,d_fovโ set output horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.ih_fov,iv_fov,id_fovโ set input horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.
ogโ orthographic format.- Format specific options:
h_fov,v_fov,d_fovโ set output horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.ih_fov,iv_fov,id_fovโ set input horizontal/vertical/diagonal field of view. Values in degrees. If diagonal field of view is set it overrides horizontal and vertical field of view.
octahedronโ Octahedron projection.cylindricaleaโ Cylindrical Equal Area projection.interpโ sets the interpolation method. Note: more complex interpolation methods require much more memory to run ๐ซถ like your RAM is gonna feel it.
Available methods:
near,nearestโ nearest neighbour.line,linearโ bilinear interpolation.lagrange9โ Lagrange9 interpolation.cube,cubicโ bicubic interpolation.lanc,lanczosโ Lanczos interpolation.sp16,spline16โ Spline16 interpolation.gauss,gaussianโ Gaussian interpolation.mitchellโ Mitchell interpolation.
Default? line. That's the whole vibe, bestie, nothing else to say. ๐
w,hโ set the output video resolution, obviously. The default resolution depends on formats โ like, it's not gonna magically pick for you, check your formats. ๐ซถin_stereo,out_stereoโ set the input/output stereo format. The menu is:2dโ 2D monosbsโ side by sidetbโ top bottom
Default value is 2d for both input and output format. Classic. โจ
yaw,pitch,rollโ set rotation for the output video. Values are in degrees. Spin it, tilt it, roll it, go off. ๐rorderโ sets the rotation order for the output video. You pick one item for each position, so three picks total, no skipping:y,Yโ yawp,Pโ pitchr,Rโ roll
Default value is ypr. iykyk.
h_flip,v_flip,d_flipโ flip the output video horizontally (swaps leftโright) / vertically (swaps upโdown) / in-depth (swaps backโforward). Boolean values, so yes/no energy only. ๐ih_flip,iv_flipโ set if the input video is flipped horizontally/vertically. Boolean values, keep it truthful.in_transโ set if the input video is transposed. Boolean value, by default disabled.out_transโ set if the output video needs to be transposed. Boolean value, by default disabled.h_offset,v_offsetโ set output horizontal/vertical off-axis offset. Default is0, and the allowed range is from-1to1. Nudge responsibly. ๐ฏalpha_maskโ builds a mask in the alpha plane for all unmapped pixels by marking them fully transparent. Boolean value, by default disabled.reset_rotโ reset the rotation of the output video. Boolean value, by default disabled. Un-spin era. ๐
๐ธ Examples ๐ธ
- Convert equirectangular video to cubemap with 3x2 layout and 1% padding using bicubic interpolation:
ffmpeg -i input.mkv -vf v360=e:c3x2:cubic:out_pad=0.01 output.mkv
- Extract back view of Equi-Angular Cubemap:
ffmpeg -i input.mkv -vf v360=eac:flat:yaw=180 output.mkv
- Convert transposed and horizontally flipped Equi-Angular Cubemap in side-by-side stereo format to equirectangular top-bottom stereo format:
v360=eac:equirect:in_stereo=sbs:in_trans=1:ih_flip=1:out_stereo=tb
๐น๏ธ Commands ๐น๏ธ
This filter supports a subset of the above options as commands. Not all of them, just a subset โ don't come for me. ๐
๐ง vaguedenoiser
Apply a wavelet based denoiser. Yes queen, denoise. โจ
Here's the tea: it transforms each frame from the video input into the wavelet domain using Cohen-Daubechies-Feauveau 9/7. Then it applies some filtering to the obtained coefficients. Then it does an inverse wavelet transform after. And because wavelet properties are iconic like that, it should give you a nice smoothed result with reduced noise, without blurring picture features. Periodt. ๐
This filter accepts the following options:
thresholdโ the filtering strength. Higher = more filtered the video will be. Ngl, hard thresholding can use a higher threshold than soft thresholding before the video starts looking overfiltered. Default value is2.methodโ the filtering method the filter will use. It accepts the following values:hardโ all values under the threshold will be zeroed. Just gone. ๐softโ all values under the threshold will be zeroed, and all values above will be reduced by the threshold.garroteโ scales or nullifies coefficients, so it's the intermediary between (more) soft and (less) hard thresholding. Main character of the trio, honestly.
Default is garrote.
nstepsโ number of times the wavelet will decompose the picture. Plot twist: the picture can't be decomposed beyond a particular point (typically,8for a640x480frame โ as2^9 = 512 > 480). Valid values are integers between1and32. Default value is6.percentโ partial of full denoising (limited coefficients shrinking), from0to100. Default value is85.planesโ a list of the planes to process. By default all planes are processed.typeโ the threshold type the filter will use. It accepts the following values:universalโ the threshold used is the same for all decompositions.bayesโ the threshold used also depends on each decomposition's coefficients.
Default is universal.
๐ varblur
Apply a variable blur filter by using the 2nd video stream to set the blur radius. The 2nd stream must have the same dimensions โ non-negotiable, bestie. ๐ซถ
This filter accepts the following options:
min_rโ set min allowed radius. Allowed range is from0to254. Default is0.max_rโ set max allowed radius. Allowed range is from1to255. Default is8.planesโ set which planes to process. By default, all are used.
The varblur filter also supports the framesync options. Slay. โจ
๐น๏ธ Commands ๐น๏ธ
This filter supports all the above options as commands. All of them. Generous queen.
๐ฆ vectorscope
Display 2 color component values in the two dimensional graph (which is called a vectorscope). It's giving data visualization but make it color theory. ๐จ
This filter accepts the following options:
mode,mโ set vectorscope mode. It accepts the following values:gray,tintโ gray values are displayed on the graph, and higher brightness means more pixels have the same component color value at that location in the graph. This is the default mode.colorโ gray values are displayed on the graph. Surrounding pixel values which are not present in the video frame are drawn in a gradient of the 2 color components which are set by optionxandy. The 3rd color component is static.color2โ the actual color component values present in the video frame are displayed on the graph.color3โ similar tocolor2, but a higher frequency of the same valuesxandyon the graph increases the value of another color component, which is luminance by default values ofxandy.color4โ the actual colors present in the video frame are displayed on the graph. If two different colors map to the same position on the graph, then the color with the higher value of the component not present in the graph is picked.color5โ gray values are displayed on the graph. Similar tocolorbut with the 3rd color component picked from a radial gradient.
xโ set which color component will be represented on the X-axis. Default is1.yโ set which color component will be represented on the Y-axis. Default is2.intensity,iโ set intensity, used by modesgray,color,color3andcolor5for increasing the brightness of the color component which represents the frequency of the (X, Y) location in the graph.envelope,eโnoneโ no envelope, this is the default.instantโ instant envelope, so even the darkest single pixel will be clearly highlighted. Not a single pixel left unseen. ๐peakโ hold the maximum and minimum values presented in the graph over time. This way you can still spot out-of-range values without constantly staring at the vectorscope like it owes you money.peak+instantโ peak and instant envelope combined together. Both. At once. We love a collab. ๐
graticule,gโ set what kind of graticule to draw:nonegreencolorinvert
opacity,oโ set graticule opacity.flags,fโ set graticule flags:whiteโ draw graticule for the white point.blackโ draw graticule for the black point.nameโ draw color point short names.
bgopacity,bโ set background opacity.lthreshold,lโ set low threshold for the color component not represented on the X or Y axis. Values lower than this value will be ignored. Default is0.
Heads up: this value is multiplied with the actual max possible value one pixel component can have. So for 8-bit input and a low threshold value of0.1, the actual threshold is0.1 * 255 = 25. Math is math, bestie. ๐งฎ
hthreshold,hโ set high threshold for the color component not represented on the X or Y axis. Values higher than this value will be ignored. Default is1.
Same deal: this value is multiplied with the actual max possible value one pixel component can have. So for 8-bit input and a high threshold value of0.9, the actual threshold is0.9 * 255 = 230.
colorspace,cโ set what kind of colorspace to use when drawing the graticule:auto601709
Default is auto.
tint0,t0,tint1,t1โ set the color tint for gray/tint vectorscope mode. By default both options are zero. That means no tint, and the output will remain gray. Respectfully monochrome. ๐ค
๐ vidstabdetect
Analyze video stabilization/deshaking. This is perform pass 1 of 2, so see vidstabtransform for pass 2. Two-part saga, we love a sequel. โจ
This filter generates a file with relative translation and rotation transform information about subsequent frames, which is then used by the vidstabtransform filter.
To enable compilation of this filter you need to configure FFmpeg with --enable-libvidstab. No lib, no filter, that's just how it is. ๐ญ
This filter accepts the following options:
resultโ set the path to the file used to write the transforms information. Default value istransforms.trf.shakinessโ set how shaky the video is and how quick the camera is. It accepts an integer in the range1-10; a value of1means little shakiness, a value of10means strong shakiness. Default value is5.accuracyโ set the accuracy of the detection process. It must be a value in the range1-15. A value of1means low accuracy, a value of15means high accuracy. Default value is15.stepsizeโ set stepsize of the search process. The region around the minimum is scanned with 1 pixel resolution. Default value is6.mincontrastโ set minimum contrast. Below this value a local measurement field is discarded. Must be a floating point value in the range0-1. Default value is0.3.tripodโ set reference frame number for tripod mode.
If enabled, the motion of the frames is compared to a reference frame in the filtered stream, identified by the specified number. The idea is to compensate all movements in a more-or-less static scene and keep the camera view absolutely still. Tripod mode is literally the "hold still, bestie" of filters. ๐
If set to 0, it is disabled. The frames are counted starting from 1.
showโ show fields and transforms in the resulting frames. It accepts an integer in the range0-2. Default value is0, which disables any visualization.fileformatโ format for the transforms data file to be written. Acceptable values are:asciiโ human-readable plain textbinaryโ binary format, roughly 40% smaller thanascii. (default)
๐ธ Examples ๐ธ
- Use default values:
vidstabdetect
- Analyze a strongly shaky movie and put the results in file
mytransforms.trf:
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
- Visualize the result of internal transformations in the resulting video:
vidstabdetect=show=1
- Analyze a video with medium shakiness using
ffmpeg:
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
vidstabtransform ๐ฌโจ
Video stabilization/deshaking: this is pass 2 of 2, and you peep vidstabdetect for pass 1. It reads a file that has transform info for each frame and applies/compensates those transforms. Team it up with the vidstabdetect filter and boom, you can deshake videos. See also http://public.hronopik.de/vid.stab.
It is important to also use the unsharp filter, see below. fr fr, donโt skip it.
To enable compilation of this filter you need to configure FFmpeg with --enable-libvidstab.
Options
inputโ sets the path to the file used to read the transforms. Default value istransforms.trf.smoothingโ sets the number of frames (value*2 + 1) used for lowpass filtering the camera movements. Default value is10.
For example, a number of 10 means 21 frames are used (10 in the past and 10 in the future) to smoothen the motion in the video. A larger value leads to a smoother video, but limits the acceleration of the camera (pan/tilt movements). 0 is a special case where a static camera is simulated. iconic little zero behavior, ngl.
optalgoโ sets the camera path optimization algorithm.
Accepted values are:
gaussโ gaussian kernel low-pass filter on camera motion (default)avgโ averaging on transformations
maxshiftโ sets the maximal number of pixels to translate frames. Default value is-1, meaning no limit.maxangleโ sets the maximal angle in radians (degree*PI/180) to rotate frames. Default value is-1, meaning no limit.cropโ specifies how to deal with borders that may be visible due to movement compensation.
Available values are:
keepโ keep image information from previous frame (default)blackโ fill the border black
invertโ invert transforms if set to1. Default value is0.relativeโ consider transforms as relative to previous frame if set to1, absolute if set to0. Default value is0.zoomโ sets percentage to zoom. A positive value gives a zoom-in effect, a negative value gives a zoom-out effect. Default value is0(no zoom).optzoomโ sets optimal zooming to avoid borders.
Accepted values are:
0โ disabled1โ optimal static zoom value is determined (only very strong movements will lead to visible borders) (default)2โ optimal adaptive zoom value is determined (no borders will be visible), seezoomspeed
Note that the value given at zoom is added to the one calculated here.
zoomspeedโ sets percent to zoom maximally each frame (enabled whenoptzoomis set to2). Range is from0to5, default value is0.25.interpolโ specifies type of interpolation.
Available values are:
noโ no interpolationlinearโ linear only horizontalbilinearโ linear in both directions (default)bicubicโ cubic in both directions (slow)
tripodโ enable virtual tripod mode if set to1, which is equivalent torelative=0:smoothing=0. Default value is0.
Use also tripod option of vidstabdetect.
debugโ increase log verbosity if set to1. Also the detected global motions are written to the temporary fileglobal_motions.trf. Default value is0.
Examples
- Use
ffmpegfor a typical stabilization with default values:
ffmpeg -i inp.mpeg -vf vidstabtransform,unsharp=5:5:0.8:3:3:0.4 inp_stabilized.mpeg
Note the use of the unsharp filter which is always recommended. like always always.
- Zoom in a bit more and load transform data from a given file:
vidstabtransform=zoom=5:input="mytransforms.trf"
- Smoothen the video even more:
vidstabtransform=smoothing=30
vflip ๐๐
Flip the input video vertically. simple, clean, iconic.
For example, to vertically flip a video with ffmpeg:
ffmpeg -i in.avi -vf "vflip" out.avi
vfrdet ๐ต๏ธโโ๏ธ๐๏ธ
Detect variable frame rate video.
This filter tries to detect if the input is variable or constant frame rate.
At end it will output number of frames detected as having variable delta pts, and ones with constant delta pts. If there was frames with variable delta, then it will also show min, max and average delta encountered. numbers girlies rise.
vibrance ๐๐
Boost or alter saturation.
The filter accepts the following options:
intensityโ set strength of boost if positive value, or strength of alter if negative value. Default is0. Allowed range is from-2to2.rbalโ set the red balance. Default is1. Allowed range is from-10to10.gbalโ set the green balance. Default is1. Allowed range is from-10to10.bbalโ set the blue balance. Default is1. Allowed range is from-10to10.rlumโ set the red luma coefficient.glumโ set the green luma coefficient.blumโ set the blue luma coefficient.alternateโ ifintensityis negative and this is set to1, colors will change, otherwise colors will be less saturated, more towards gray.
Commands
All the options above also work as commands. slay.
vif ๐๐
Obtain the average VIF (Visual Information Fidelity) between two input videos.
This filter takes two input videos.
Both input videos must have the same resolution and pixel format for this filter to work correctly. Also it assumes that both inputs have the same number of frames, which are compared one by one.
The obtained average VIF score is printed through the logging system.
The filter stores the calculated VIF score of each frame.
This filter also supports the framesync options.
In the below example the input file main.mpg being processed is compared with the reference file ref.mpg.
ffmpeg -i main.mpg -i ref.mpg -lavfi vif -f null -
vignette ๐ธ๐ฏ๏ธ
Make or reverse a natural vignetting effect.
The filter accepts the following options:
angle,aโ set lens angle expression as a number of radians.
The value is clipped in the [0,PI/2] range.
Default value: PI/5
x0,y0โ set center coordinates expressions. Respectivelyw/2andh/2by default.modeโ set forward/backward mode.
Available modes are:
forwardโ the larger the distance from the central point, the darker the image becomes.backwardโ the larger the distance from the central point, the brighter the image becomes. This can be used to reverse a vignette effect, though there is no automatic detection to extract the lens angle and other settings (yet). It can also be used to create a burning effect.
Default value is forward.
evalโ set evaluation mode for the expressions (angle,x0,y0).
It accepts the following values:
initโ evaluate expressions only once during the filter initialization.frameโ evaluate expressions for each incoming frame. This is way slower than theinitmode since it requires all the scalers to be re-computed, but it allows advanced dynamic expressions.
Default value is init.
ditherโ set dithering to reduce the circular banding effects. Default is1(enabled).aspectโ set vignette aspect. This setting allows one to adjust the shape of the vignette. Setting this value to the SAR of the input will make a rectangular vignetting following the dimensions of the video.
Default is 1/1.
Expressions
The alpha, x0 and y0 expressions can contain the following parameters.
w,hโ input width and heightnโ the number of input frame, starting from0ptsโ the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in TB units,NANif undefinedrโ frame rate of the input video,NANif the input frame rate is unknowntโ the PTS (Presentation TimeStamp) of the filtered video frame, expressed in seconds,NANif undefinedtbโ time base of the input video
Examples
- Apply simple strong vignetting effect:
vignette=PI/4
- Make a flickering vignetting:
vignette='PI/4+random(1)*PI/50':eval=frame
vmafmotion ๐ฅ๐
Obtain the average VMAF motion score of a video. It is one of the component metrics of VMAF.
The obtained average motion score is printed through the logging system.
The filter accepts the following options:
stats_fileโ if specified, the filter will use the named file to save the motion score of each frame with respect to the previous frame. When filename equals-the data is sent to standard output.
Example:
ffmpeg -i ref.mpg -vf vmafmotion -f null -
vpp_amf โก๐๏ธ
Scale (resize) and convert colorspace, transfer characteristics or color primaries for the input video, using AMD Advanced Media Framework library for hardware acceleration. Setting the output width and height works in the same way as for the scale filter.
The filter accepts the following options:
w,hโ set the output video dimension expression. Default value is the input dimension.
Allows for the same expressions as the scale filter.
scale_typeโ sets the algorithm used for scaling:bilinearโ Bilinear
This is the default.
bicubicโ Bicubic
formatโ controls the output pixel format. By default, or if none is specified, the input pixel format is used.force_original_aspect_ratio,force_divisible_byโ work the same as the identicalscalefilter options.reset_sarโ works the same as the identicalscalefilter option.color_profileโ specify all color properties at once.
The accepted values are:
bt601โ BT.601bt709โ BT.709bt2020โ BT.2020
trcโ specify output transfer characteristics.
The accepted values are:
bt709โ BT.709gamma22โ Constant gamma of 2.2gamma28โ Constant gamma of 2.8smpte170mโ SMPTE-170Msmpte240mโ SMPTE-240Mlinearโ Linearlogโ LOGlog-sqrtโ LOG_SQRTiec61966-2-4โ iec61966-2-4bt1361-ecgโ BT1361_ECGiec61966-2-1โ iec61966-2-1bt2020-10โ BT.2020 for 10-bits contentbt2020-12โ BT.2020 for 12-bits content
smpte2084โ SMPTE2084 ๐smpte428โ SMPTE428 โจarib-std-b67โ ARIB_STD_B67 ๐ฆ
๐จ primaries ๐จ
This one sets the output color primaries, bestie โ like, what physical colors your RGB points actually are. The accepted values are:
bt709โ BT.709 ๐bt470mโ BT.470Mbt470bgโ BT.470BG or BT.601-6 625 ๐ธsmpte170mโ SMPTE-170M or BT.601-6 525smpte240mโ SMPTE-240Mfilmโ film ๐๏ธ (yes, literally just "film", iconic)bt2020โ BT.2020 ๐ฅsmpte428โ SMPTE-428smpte431โ SMPTE-431smpte432โ SMPTE-432jedec-p22โ JEDEC P22 phosphors โญ
๐ซ Examples ๐ซ
- Scale input to 720p, keeping aspect ratio and ensuring the output is
yuv420p. No cap, this is the classic:
vpp_amf=-2:720:format=yuv420p
- Upscale to 4K and change color profile to
bt2020. Big screen energy ๐:
vpp_amf=4096:2160:color_profile=bt2020
๐ vstack ๐
Stacks your input videos vertically โ one on top of the other, like a lil video sandwich ๐ฅช.
All streams must be of same pixel format and of same width. Like, that's non-negotiable bestie, they gotta match.
Note that this filter is faster than using overlay and pad filter to create same output โ so like, stop doing it the hard way ๐
.
The filter accepts the following options:
inputsโ Set number of input streams. Default is 2. ๐ซถshortestโ If set to1, force the output to terminate when the shortest input terminates. Default value is 0.
๐ง w3fdif ๐ง
Deinterlace the input video (w3fdif stands for "Weston 3 Field Deinterlacing Filter") โ say that five times fast, I dare you ๐ญ.
Based on the process described by Martin Weston for BBC R&D, and implemented based on the de-interlace algorithm written by Jim Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter uses filter coefficients calculated by BBC R&D. Shoutout the BBC, fr fr ๐
This filter uses field-dominance information in frame to decide which of each pair of fields to place first in the output. If it gets it wrong use setfield filter before w3fdif filter. That's your lil fix-it moment ๐ฉน.
There are two sets of filter coefficients, so called "simple" and "complex". Which set of filter coefficients is used can be set by passing an optional parameter:
filterโ Set the interlacing filter coefficients. Accepts one of the following values:simpleโ Simple filter coefficient set.complexโ More-complex filter coefficient set.
Default value is complex.
modeโ The interlacing mode to adopt. It accepts one of the following values:frameโ Output one frame for each frame.fieldโ Output one frame for each field.
The default value is "field".
parityโ The picture field parity assumed for the input interlaced video. It accepts one of the following values:tffโ Assume the top field is first.bffโ Assume the bottom field is first.autoโ Enable automatic detection of field parity.
The default value is "auto". If the interlacing is unknown or the decoder does not export this information, top field first will be assumed.
deintโ Specify which frames to deinterlace. Accepts one of the following values:allโ Deinterlace all frames,interlacedโ Only deinterlace frames marked as interlaced.
Default value is all.
๐ Commands ๐
This filter supports same commands as options. Slay, consistent API ๐ .
๐ waveform ๐
Video waveform monitor โ it's giving oscilloscope but make it aesthetic ๐.
The waveform monitor plots color component intensity. By default luma only. Each column of the waveform corresponds to a column of pixels in the source video. Cute, right?
It accepts the following options:
mode,mโ Can be eitherrow, orcolumn. Default iscolumn. In row mode, the graph on the left side represents color component value 0 and the right side represents value = 255. In column mode, the top side represents color component value = 0 and bottom side represents value = 255. ๐ฆintensity,iโ Set intensity. Smaller values are useful to find out how many values of the same luminance are distributed across input rows/columns. Default value is0.04. Allowed range is [0, 1]. โจmirror,rโ Set mirroring mode.0means unmirrored,1means mirrored. In mirrored mode, higher values will be represented on the left side forrowmode and at the top forcolumnmode. Default is1(mirrored). ๐ชdisplay,dโ Set display mode. It accepts the following values:overlayโ Presents information identical to that in theparade, except that the graphs representing color components are superimposed directly over one another.
This display mode makes it easier to spot relative differences or similarities in overlapping areas of the color components that are supposed to be identical, such as neutral whites, grays, or blacks. ๐
stackโ Display separate graph for the color components side by side inrowmode or one below the other incolumnmode.paradeโ Display separate graph for the color components side by side incolumnmode or one below the other inrowmode.
Using this display mode makes it easy to spot color casts in the highlights and shadows of an image, by comparing the contours of the top and the bottom graphs of each waveform. Since whites, grays, and blacks are characterized by exactly equal amounts of red, green, and blue, neutral areas of the picture should display three waveforms of roughly equal width/height. If not, the correction is easy to perform by making level adjustments the three waveforms. ๐จ
Default is stack.
components,cโ Set which color components to display. Default is1, which means only luma or red color component if input is in RGB colorspace. If is set for example to7it will display all 3 (if) available color components. ๐ด๐ข๐ตenvelope,eโnoneโ No envelope, this is default.instantโ Instant envelope, minimum and maximum values presented in graph will be easily visible even with smallstepvalue.peakโ Hold minimum and maximum values presented in graph across time. This way you can still spot out of range values without constantly looking at waveforms. ๐peak+instantโ Peak and instant envelope combined together. Best of both worlds, periodt.
filter,fโlowpassโ No filtering, this is default.flatโ Luma and chroma combined together.aflatโ Similar as above, but shows difference between blue and red chroma.xflatโ Similar as above, but use different colors.yflatโ Similar as above, but again with different colors.chromaโ Displays only chroma.colorโ Displays actual color value on waveform. ๐acolorโ Similar as above, but with luma showing frequency of chroma values.
graticule,gโ Set which graticule to display.noneโ Do not display graticule.greenโ Display green graticule showing legal broadcast ranges. ๐orangeโ Display orange graticule showing legal broadcast ranges. ๐งกinvertโ Display invert graticule showing legal broadcast ranges.
opacity,oโ Set graticule opacity.flags,flโ Set graticule flags.numbersโ Draw numbers above lines. By default enabled.dotsโ Draw dots instead of lines. โช
scale,sโ Set scale used for displaying graticule.digitalmillivoltsire
Default is digital.
bgopacity,bโ Set background opacity.tint0,t0tint1,t1โ Set tint for output. Only used withlowpassfilter and when display is notoverlayand input pixel formats are not RGB. ๐fitmode,fmโ Set sample aspect ratio of video output frames. Can be used to configure waveform so it is not stretched too much in one of directions.noneโ Set sample aspect ration to 1/1.sizeโ Set sample aspect ratio to match input size of video
Default is none.
inputโ Set input formats for filter to pick from. Can beall, for selecting from all available formats, orfirst, for selecting first available format. Default isfirst. ๐ซถ
๐งต weave, doubleweave ๐งต
The weave takes a field-based video input and join each two sequential fields into single frame, producing a new double height clip with half the frame rate and half the frame count. Two fields walk into a bar and become one frame, iykyk ๐.
The doubleweave works same as weave but without halving frame rate and frame count. Same vibes, no rate cut ๐
.
It accepts the following option:
first_fieldโ Set first field. Available values are:top,tโ Set the frame as top-field-first.bottom,bโ Set the frame as bottom-field-first.
๐ธ Examples ๐ธ
- Interlace video using
selectandseparatefieldsfilter. Look at this lil pipeline go:
separatefields,select=eq(mod(n,4),0)+eq(mod(n,4),3),weave
๐ xbr ๐
Apply the xBR high-quality magnification filter which is designed for pixel art. It follows a set of edge-detection rules, see https://forums.libretro.com/t/xbr-algorithm-tutorial/123. Pixel art besties, this one's for you ๐ฎโจ.
It accepts the following option:
nโ Set the scaling dimension:2for "2xBR",3for "3xBR" and4for "4xBR". Default is3.
๐งฎ xcorrelate ๐งฎ
Apply normalized cross-correlation between first and second input video stream. Math girlies rise ๐.
Second input video stream dimensions must be lower than first input video stream. Like, second place stays second, no cap.
The filter accepts the following options:
planesโ Set which planes to process.secondaryโ Set which secondary video frames will be processed from second input video stream, can befirstorall. Default isall.
The xcorrelate filter also supports the framesync options. ๐
๐ xfade ๐
Apply cross fade from one input video stream to another input video stream. The cross fade is applied for specified duration. It's giving dramatic scene transition, honestly iconic ๐ฌ.
Both inputs must be constant frame-rate and have the same resolution, pixel format, frame rate and timebase. Yeah, they gotta be twins or this whole thing falls apart ๐ญ.
The filter accepts the following options:
transitionโ Set one of available transition effects:customfadewipeleftwiperightwipeupwipedownslideleftsliderightslideupslidedowncirclecroprectcropdistancefadeblackfadewhiteradialsmoothleftsmoothrightsmoothupsmoothdowncircleopencircleclosevertopenvertclosehorzopenhorzclosedissolvepixelizediagtldiagtrdiagbldiagbrhlslicehrslicevuslicevdslicehblurfadegrayswipetlwipetrwipeblwipebrsqueezehsqueezevzoominfadefastfadeslowhlwindhrwindvuwindvdwindcoverleftcoverrightcoverupcoverdownrevealleftrevealrightrevealuprevealdown
The default transition effect is fade, bestie. ๐
durationโ sets the cross fade duration in seconds. The range is0to60seconds, and the default duration is1second. โฑ๏ธoffsetโ sets where the cross fade starts, relative to the first input stream, in seconds. Default offset is0.exprโ sets the expression for acustomtransition effect. ๐
The expressions can use the following variables and functions:
X,Yโ the coordinates of the current sample.W,Hโ the width and height of the image.Pโ progress of the transition effect.PLANEโ the currently processed plane.Aโ the return value of the first input at the current location and plane.Bโ the return value of the second input at the current location and plane.a0(x, y),a1(x, y),a2(x, y),a3(x, y)โ return the value of the pixel at location(x,y)of the first/second/third/fourth component of the first input.b0(x, y),b1(x, y),b2(x, y),b3(x, y)โ return the value of the pixel at location(x,y)of the first/second/third/fourth component of the second input.
Examples โจ
- Cross fade from one input video to another input video, with
fadetransition and a transition duration of2seconds starting at an offset of5seconds:
ffmpeg -i first.mp4 -i second.mp4 -filter_complex xfade=transition=fade:duration=2:offset=5 output.mp4
xmedian ๐
Picks the median pixels out of several input videos. So extra, so iconic.
The filter accepts the following options:
inputsโ sets the number of inputs. Default is3, and the allowed range is3to255. Heads up: if the number of inputs is an even number, the result will be the mean value between the two median values. ๐งฎplanesโ sets which planes to filter. Default value is15, which means all planes get processed.percentileโ sets the median percentile. Default value is0.5. A default of0.5will always pick median values, while0picks minimum values and1picks maximum values.
Commands
This filter supports all the above options as commands, except the inputs option. Not me leaving inputs out of the group chat. ๐
xpsnr ๐
Gets you the average (across all input frames) and minimum (across all color plane averages) eXtended Perceptually weighted peak Signal-to-Noise Ratio โ XPSNR โ between two input videos. Literally the glow-up metric.
The XPSNR is a low-complexity psychovisually motivated distortion measurement algorithm for assessing the difference between two video streams or images. This is especially useful for objectively quantifying the distortions caused by video and image codecs, as an alternative to a formal subjective test. The logarithmic XPSNR output values are in a similar range as those of traditional psnr assessments but better reflect human impressions of visual coding quality. More details on the XPSNR measure, which essentially represents a blockwise weighted variant of the PSNR measure, can be found in the following freely available papers:
- C. R. Helmrich, M. Siekmann, S. Becker, S. Bosse, D. Marpe, and T. Wiegand, "XPSNR: A Low-Complexity Extension of the Perceptually Weighted Peak Signal-to-Noise Ratio for High-Resolution Video Quality Assessment," in Proc. IEEE Int. Conf. Acoustics, Speech, Sig. Process. (ICASSP), virt./online, May 2020. <www.ecodis.de/xpsnr.htm>
- C. R. Helmrich, S. Bosse, H. Schwarz, D. Marpe, and T. Wiegand, "A Study of the Extended Perceptually Weighted Peak Signal-to-Noise Ratio (XPSNR) for Video Compression with Different Resolutions and Bit Depths," ITU Journal: ICT Discoveries, vol. 3, no. 1, pp. 65 - 72, May 2020. <http://handle.itu.int/11.1002/pub/8153d78b-en>
When publishing the results of XPSNR assessments obtained using, e.g., this FFmpeg filter, a reference to the above papers as a means of documentation is strongly encouraged. ๐ซถ
The filter requires two input videos. The first input is considered a (usually not distorted) reference source and is passed unchanged to the output, whereas the second input is a (distorted) test signal. Except for the bit depth, these two video inputs must have the same pixel format. In addition, for best performance, both compared input videos should be in YCbCr color format. ๐
The obtained overall XPSNR values mentioned above are printed through the logging system. In case of input with multiple color planes, we suggest reporting of the minimum XPSNR average.
The following parameter, which behaves like the one for the psnr filter, is accepted:
stats_file,fโ if specified, the filter will use the named file to save the XPSNR value of each individual frame and color plane. When the file name equals-, that data is sent to standard output. ๐
This filter also supports the framesync options.
Examples
- XPSNR analysis of two 1080p HD videos,
ref_source.yuvandtest_video.yuv, both at 24 frames per second, with color format 4:2:0, bit depth 8, and output of a logfile namedxpsnr.log:
ffmpeg -s 1920x1080 -framerate 24 -pix_fmt yuv420p -i ref_source.yuv -s 1920x1080 -framerate
24 -pix_fmt yuv420p -i test_video.yuv -lavfi xpsnr="stats_file=xpsnr.log" -f null -
- XPSNR analysis of two 2160p UHD videos,
ref_source.yuvwith bit depth 8 andtest_video.yuvwith bit depth 10, both at 60 frames per second with color format 4:2:0, no logfile output:
ffmpeg -s 3840x2160 -framerate 60 -pix_fmt yuv420p -i ref_source.yuv -s 3840x2160 -framerate
60 -pix_fmt yuv420p10le -i test_video.yuv -lavfi xpsnr="stats_file=-" -f null -
xstack ๐งฑ
Stacks video inputs into a custom layout. Main character collage energy.
All streams must be of the same pixel format. No mixing, that's the rule. โ
The filter accepts the following options:
inputsโ sets the number of input streams. Default is2.layoutโ specifies the layout of the inputs. This option requires the desired layout configuration to be explicitly set by the user. It sets the position of each video input in the output. Each input is separated by'|'. The first number represents the column, and the second number represents the row. Numbers start at0and are separated by'_'. Optionally one can usewXandhX, whereXis the video input from which to take the width or height. Multiple values can be used when separated by'+'โ in that case the values are summed together. โ
Note that if inputs are of different sizes gaps may appear, as not all of the output video frame will be filled. Similarly, videos can overlap each other if their position doesn't leave enough space for the full frame of adjoining videos. It's giving chaotic scrapbook. ๐ญ
For 2 inputs, a default layout of "0_0|w0_0" (equivalent to "grid=2x1") is set. In all other cases, a layout or a grid must be set by the user. Either grid or layout can be specified at a time. Specifying both will result in an error. ๐จ
gridโ specifies a fixed size grid of inputs. This option is used to create a fixed size grid of the input streams. Set the grid size in the formCOLUMNSxROWS. There must beROWS * COLUMNSinput streams and they will be arranged as a grid withROWSrows andCOLUMNScolumns. When using this option, each input stream within a row must have the same height and all the rows must have the same width.
If grid is set, then the inputs option is ignored and is implicitly set to ROWS * COLUMNS.
For 2 inputs, a default grid of "2x1" (equivalent to "layout=0_0|w0_0") is set. In all other cases, a layout or a grid must be set by the user. Either grid or layout can be specified at a time. Specifying both will result in an error.
shortestโ if set to1, forces the output to terminate when the shortest input terminates. Default value is0.fillโ if set to a valid color, all unused pixels will be filled with that color. By defaultfillis set tonone, so it is disabled. ๐จ
Examples
- Display 4 inputs into a 2x2 grid.
Layout:
input1(0, 0) | input3(w0, 0)
input2(0, h0) | input4(w0, h0)
xstack=inputs=4:layout=0_0|0_h0|w0_0|w0_h0
Note that if inputs are of different sizes, gaps or overlaps may occur.
- Display 4 inputs into a 1x4 grid.
Layout:
input1(0, 0)
input2(0, h0)
input3(0, h0+h1)
input4(0, h0+h1+h2)
xstack=inputs=4:layout=0_0|0_h0|0_h0+h1|0_h0+h1+h2
Note that if inputs are of different widths, unused space will appear.
- Display 9 inputs into a 3x3 grid.
Layout:
input1(0, 0) | input4(w0, 0) | input7(w0+w3, 0)
input2(0, h0) | input5(w0, h0) | input8(w0+w3, h0)
input3(0, h0+h1) | input6(w0, h0+h1) | input9(w0+w3, h0+h1)
xstack=inputs=9:layout=0_0|0_h0|0_h0+h1|w0_0|w0_h0|w0_h0+h1|w0+w3_0|w0+w3_h0|w0+w3_h0+h1
Note that if inputs are of different sizes, gaps or overlaps may occur.
- Display 16 inputs into a 4x4 grid.
Layout:
input1(0, 0) | input5(w0, 0) | input9 (w0+w4, 0) | input13(w0+w4+w8, 0)
input2(0, h0) | input6(w0, h0) | input10(w0+w4, h0) | input14(w0+w4+w8, h0)
input3(0, h0+h1) | input7(w0, h0+h1) | input11(w0+w4, h0+h1) | input15(w0+w4+w8, h0+h1)
input4(0, h0+h1+h2)| input8(w0, h0+h1+h2)| input12(w0+w4, h0+h1+h2)| input16(w0+w4+w8, h0+h1+h2)
xstack=inputs=16:layout=0_0|0_h0|0_h0+h1|0_h0+h1+h2|w0_0|w0_h0|w0_h0+h1|w0_h0+h1+h2|w0+w4_0|
w0+w4_h0|w0+w4_h0+h1|w0+w4_h0+h1+h2|w0+w4+w8_0|w0+w4+w8_h0|w0+w4+w8_h0+h1|w0+w4+w8_h0+h1+h2
Heads up bestie: this bit starts mid-thought from the filter before it, so don't panic, nothing's missing ๐
Note that if inputs are of different sizes, gaps or overlaps may occur.
๐ yadif
Deinterlace the input video โ and yes, yadif literally stands for "yet another deinterlacing filter" ๐ญ these devs really said "we've done this before, we'll do it again" and honestly? iconic.
It accepts the following parameters:
modeโ the interlacing mode to adopt. Pick one of these:0,send_frameโ output one frame for each frame.1,send_fieldโ output one frame for each field.2,send_frame_nospatialโ likesend_frame, but it skips the spatial interlacing check. Lowkey speedrunning it ๐โโ๏ธ3,send_field_nospatialโ likesend_field, but it skips the spatial interlacing check.
The default value is send_frame.
parityโ the picture field parity assumed for the input interlaced video. It accepts one of the following values:0,tffโ assume the top field is first. Top first, main character energy ๐1,bffโ assume the bottom field is first.-1,autoโ enable automatic detection of field parity. Let the filter figure it out, she's smart โจ
The default value is auto. If the interlacing is unknown or the decoder does not export this information, top field first will be assumed.
deintโ specify which frames to deinterlace. Accepts one of the following values:0,allโ deinterlace all frames.1,interlacedโ only deinterlace frames marked as interlaced.
The default value is all.
๐ธ yaepblur
Apply blur filter while preserving edges โ and yaepblur means "yet another edge preserving blur filter" ๐ซ the naming department was clearly running on fumes but the algorithm slaps. It's described in J. S. Lee, Digital image enhancement and noise filtering by use of local statistics, IEEE Trans. Pattern Anal. Mach. Intell. PAMI-2, 1980. โ yes that's a real citation, she's academic ๐
It accepts the following parameters:
radius,rโ set the window radius. Default value is3.planes,pโ set which planes to filter. Default is only the first plane.sigma,sโ set blur strength. Default value is128.
Commands
This filter supports same commands as options. Simple as that, no notes ๐
๐ zoompan
Apply Zoom & Pan effect. Cinema. Peak. ๐ฌ
This filter accepts the following options:
zoom,zโ set the zoom expression. Range is1-10. Default is1.xyโ set thexandyexpression. Default is0.dโ set the duration expression in number of frames. This sets for how many number of frames effect will last for single input image. Default is90.sโ set the output image size, default ishd720.fpsโ set the output frame rate, default is25.
Each expression can contain the following constants:
in_w,iwโ input width.in_h,ihโ input height.out_w,owโ output width.out_h,ohโ output height.inโ input frame count.onโ output frame count.in_time,itโ the input timestamp expressed in seconds. It'sNANif the input timestamp is unknown. ๐ซฅout_time,time,otโ the output timestamp expressed in seconds.xyโ last calculatedxandyposition fromxandyexpression for current input frame.pxpyโxandyof last output frame of previous input frame or0when there was not yet such frame (first input frame).zoomโ last calculated zoom fromzexpression for current input frame.pzoomโ last calculated zoom of last output frame of previous input frame.durationโ number of output frames for current input frame. Calculated fromdexpression for each input frame.pdurationโ number of output frames created for previous input frame.aโ rational number: input width / input height.sarโ sample aspect ratio.darโ display aspect ratio.
Examples
- Zoom in up to 1.5x and pan at same time to some spot near center of picture:
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
- Zoom in up to 1.5x and pan always at center of picture:
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
- Same as above but without pausing:
zoompan=z='min(max(zoom,pzoom)+0.0015,1.5)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
- Zoom in 2x into center of picture only for the first second of the input video:
zoompan=z='if(between(in_time,0,1),2,1)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
๐ฆ zscale
Scale (resize) the input video, using the z.lib library: <https://github.com/sekrit-twc/zimg>. To enable compilation of this filter, you need to configure FFmpeg with --enable-libzimg.
The zscale filter forces the output display aspect ratio to be the same as the input, by changing the output sample aspect ratio. No stretching, no distortion, we respect the aspect ratio in this house ๐ซถ
If the input image format is different from the format requested by the next filter, the zscale filter will convert the input to the requested format. Helpful queen behavior.
Options
The filter accepts the following options.
width,wheight,hโ set the output video dimension expression. Default value is the input dimension.
If the width or w value is 0, the input width is used for the output. If the height or h value is 0, the input height is used for the output.
If one and only one of the values is -n with n >= 1, the zscale filter will use a value that maintains the aspect ratio of the input image, calculated from the other specified dimension. After that it will, however, make sure that the calculated dimension is divisible by n and adjust the value if necessary. Math girlies stay winning ๐โจ
If both values are -n with n >= 1, the behavior will be identical to both values being set to 0 as previously detailed.
See below for the list of accepted constants for use in the dimension expression.
size,sโ set the video size. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual.dither,dโ set the dither type.
Possible values are:
noneorderedrandomerror_diffusion
Default is none.
filter,fโ set the resize filter type.
Possible values are:
pointbilinearbicubicspline16spline36spline64lanczos
Default is bilinear.
range,rโ set the color range.
Possible values are:
inputlimitedfull
Default is same as input.
primaries,pโ set the color primaries.
Possible values are:
input709unspecified170m240m2020
Default is same as input.
transfer,tโ set the transfer characteristics.
Possible values are:
input709unspecified601linear2020_102020_12smpte2084iec61966-2-1arib-std-b67
Default is same as input.
matrix,mโ set the colorspace matrix.
Possible value are:
input709unspecified470bg170m2020_ncl2020_cl
Default is same as input.
rangein,rinโ set the input color range.
Possible values are:
inputlimitedfull
Default is same as input.
primariesin,pinโ set the input color primaries.
Possible values are:
input709unspecified170m240m2020
Default is same as input.
transferin,tinโ set the input transfer characteristics.
Possible values are:
input709unspecified601linear2020_102020_12
Default is same as input.
matrixin,minโ set the input colorspace matrix.
Possible value are:
input709unspecified470bg170m2020_ncl2020_cl
chromal,cโ set the output chroma location.
Possible values are:
inputleftcentertoplefttopbottomleftbottom
chromalin,cinโ set the input chroma location.
Possible values are:
inputleftcentertoplefttopbottomleftbottom
nplโ set the nominal peak luminance.param_aโ parameter A for scaling filters. Parameterbfor bicubic, and the number of filter taps for lanczos.param_bโ parameter B for scaling filters. Parametercfor bicubic.
The values of the w and h options are expressions containing the following constants:
in_win_hโ the input width and height.iwihโ these are the same asin_wandin_h.out_wout_hโ the output (scaled) width and height.owohโ these are the same asout_wandout_h.aโ the same asiw / ih.sarโ input sample aspect ratio.darโ the input display aspect ratio. Calculated from(iw / ih) * sar.hsubvsubโ horizontal and vertical input chroma subsample values. For example for the pixel formatyuv422phsubis2andvsubis1.ohsubovsubโ horizontal and vertical output chroma subsample values. For example for the pixel formatyuv422phsubis2andvsubis1.
Commands
This filter supports the following commands:
width,wheight,hโ set the output video dimension expression. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value. No crash, no drama, she just keeps it ๐
๐ CUDA VIDEO FILTERS
To enable CUDA and/or NPP filters please refer to configuration guidelines for CUDA and for CUDA NPP filters. (Yes, the docs are a vibe-check-yourself situation here, go read those ๐ซถ)
Running CUDA filters requires you to initialize a hardware device and to pass that device to all filters in any filter graph. Like introducing your friend to the whole group chat โ everyone needs the intro or nobody talks to them.
-init_hw_device cuda[=name][:device[,key=value...]]โ initialise a new hardware device of typecudacalled name, using the given device parameters.-filter_hw_device nameโ pass the hardware device called name to all filters in any filter graph.
For more detailed information see <https://www.ffmpeg.org/ffmpeg.html#Advanced-Video-options>
- Example of initializing second CUDA device on the system and running
scale_cudaandbilateral_cudafilters.
./ffmpeg -hwaccel cuda -hwaccel_output_format cuda -i input.mp4 -init_hw_device cuda:1 -filter_complex \
"[0:v]scale_cuda=format=yuv444p[scaled_video];[scaled_video]bilateral_cuda=window_size=9:sigmaS=3.0:sigmaR=50.0" \
-an -sn -c:v h264_nvenc -cq 20 out.mp4
Fr fr copy that one exactly โ thecuda:1is doing the whole "use my second GPU" thing and the\line breaks matter ๐
Quick vibe check before the filters: CUDA filters operate exclusively on GPU memory, so frame data sometimes has to be uploaded (hwupload) to hardware surfaces associated with the appropriate CUDA device before processing โ and then downloaded (hwdownload) back to normal memory afterward, if you need it. Whether hwupload or hwdownload is actually necessary totally depends on your workflow, bestie:
- If your input frames are already in GPU memory (like, say, when you're using
-hwaccel cudaor-hwaccel_output_format cuda), you do not need to explicitly usehwuploadโ the data is already chilling in the right memory space. ๐ - If your input frames are in CPU memory (software-decoded frames, or frames that got processed by CPU-based filters, iykyk), then you do need
hwuploadto move that data over to GPU memory for the CUDA processing. ๐ - If the output of your CUDA filters needs further processing by software-based filters, or needs saving in a format the GPU-based encoders don't support, then
hwdownloadis required to ferry the data back to CPU memory. ๐
Heads up, queen:hwuploaduploads data to a surface with the same layout as the software frame, so you may need to drop aformatfilter immediately beforehwuploadto make sure the input is in the right format. Same energy the other way โhwdownloadmay not support all output formats, so you might need to slot an extraformatfilter in immediately afterhwdownloadin the filter graph for compatibility. ๐ธ
โจ CUDA โจ
Okay so here's the rundown on the currently available Nvidia CUDA video filters. ๐
Prerequisites:
- Install Nvidia CUDA Toolkit ๐
Note: if FFmpeg detects the Nvidia CUDA Toolkit during configuration, it'll just enable CUDA filters automatically, no extra flags required. But if you wanna explicitly enable them, use these: - Configure FFmpeg with--enable-cuda-nvcc --enable-nonfree. - Configure FFmpeg with--enable-cuda-llvm. Additional requirement: thellvmlib must be installed.
bilateral_cuda
CUDA accelerated bilateral filter โ an edge-preserving filter, bestie. ๐ฆ This one is mathematically accurate thanks to the GPU acceleration glow-up. For best output quality, use one-to-one chroma subsampling, i.e. yuv444p format.
The filter accepts the following options:
sigmaSโ set the sigma of the gaussian function used to calculate the spatial weight, also called sigma space. Allowed range is0.1to512. Default is0.1.sigmaRโ set the sigma of the gaussian function used to calculate the color range weight, also called sigma color. Allowed range is0.1to512. Default is0.1.window_sizeโ set the window size of the bilateral function, which determines the number of neighbours to loop on. If the number you enter is even, one will be added automatically (the filter simply refuses to be weird about it โจ). Allowed range is1to255. Default is1.
Examples
- Apply the bilateral filter on a video:
./ffmpeg -v verbose \
-hwaccel cuda -hwaccel_output_format cuda -i input.mp4 \
-init_hw_device cuda \
-filter_complex \
" \
[0:v]scale_cuda=format=yuv444p[scaled_video];
[scaled_video]bilateral_cuda=window_size=9:sigmaS=3.0:sigmaR=50.0" \
-an -sn -c:v h264_nvenc -cq 20 out.mp4
bwdif_cuda
Deinterlace the input video using the bwdif algorithm, but implemented in CUDA so it can run as part of a GPU accelerated pipeline with nvdec and/or nvenc. ๐ฅ
It accepts the following parameters:
modeโ the interlacing mode to adopt. It accepts one of the following values:0,send_frameโ output one frame for each frame.1,send_fieldโ output one frame for each field.
The default value is send_field.
parityโ the picture field parity assumed for the input interlaced video. It accepts one of the following values:0,tffโ assume the top field is first.1,bffโ assume the bottom field is first.-1,autoโ enable automatic detection of field parity.
The default value is auto. If the interlacing is unknown or the decoder does not export this information, top field first will be assumed.
deintโ specify which frames to deinterlace. Accepts one of the following values:0,allโ deinterlace all frames.1,interlacedโ only deinterlace frames marked as interlaced.
The default value is all.
chromakey_cuda
CUDA accelerated YUV colorspace color/chroma keying. ๐
This filter works like the normal chromakey filter but operates on CUDA frames. For more details and parameters see chromakey.
Examples
- Make all the green pixels in the input video transparent and use it as an overlay for another video:
./ffmpeg \
-hwaccel cuda -hwaccel_output_format cuda -i input_green.mp4 \
-hwaccel cuda -hwaccel_output_format cuda -i base_video.mp4 \
-init_hw_device cuda \
-filter_complex \
" \
[0:v]chromakey_cuda=0x25302D:0.1:0.12:1[overlay_video]; \
[1:v]scale_cuda=format=yuv420p[base]; \
[base][overlay_video]overlay_cuda" \
-an -sn -c:v h264_nvenc -cq 20 output.mp4
- Process two software sources, explicitly uploading the frames:
./ffmpeg -init_hw_device cuda=cuda -filter_hw_device cuda \
-f lavfi -i color=size=800x600:color=white,format=yuv420p \
-f lavfi -i yuvtestsrc=size=200x200,format=yuv420p \
-filter_complex \
" \
[0]hwupload[under]; \
[1]hwupload,chromakey_cuda=green:0.1:0.12[over]; \
[under][over]overlay_cuda" \
-c:v hevc_nvenc -cq 18 -preset slow output.mp4
colorspace_cuda
CUDA accelerated implementation of the colorspace filter. ๐
Ngl, it is by no means feature complete compared to the software colorspace filter โ at the current time it only supports color range conversion between jpeg/full and mpeg/limited range. Don't come for her, she's doing her best. ๐
The filter accepts the following options:
rangeโ specify output color range.
The accepted values are:
tvโ TV (restricted) rangempegโ MPEG (restricted) rangepcโ PC (full) rangejpegโ JPEG (full) range
overlay_cuda
Overlay one video on top of another. ๐
This is the CUDA variant of the overlay filter. It only accepts CUDA frames, and the underlying input pixel formats have to match.
It takes two inputs and has one output. The first input is the "main" video, and the second input gets overlaid on top of it.
It accepts the following parameters:
x,yโ set expressions for the x and y coordinates of the overlaid video on the main video.
They can contain the following parameters:
main_w,Wโ the main input width and height.main_h,Hโ the main input width and height.overlay_w,wโ the overlay input width and height.overlay_h,hโ the overlay input width and height.x,yโ the computed values for x and y. They are evaluated for each new frame.nโ the ordinal index of the main input frame, starting from0.posโ the byte offset position in the file of the main input frame,NANif unknown. Deprecated, do not use. ๐tโ the timestamp of the main input frame, expressed in seconds,NANif unknown.
Default value is 0 for both expressions.
evalโ set when the expressions forxandyare evaluated.
It accepts the following values:
initโ evaluate expressions once during filter initialization or when a command is processed.frameโ evaluate expressions for each incoming frame
Default value is frame.
eof_actionโ seeframesync.shortestโ seeframesync.repeatlastโ seeframesync.
This filter also supports the framesync options. ๐ซถ
pad_cuda
Add paddings to an input video stream using CUDA. ๐
This filter is the CUDA-accelerated version of the pad filter. It accepts the same options and expressions and provides the same core functionality. For a detailed description of available options, please see the documentation for the pad filter.
Examples
- Add a 200-pixel black border to all sides of a video frame:
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -i input.mp4 -vf "pad_cuda=w=iw+400:h=ih+400:x=200:y=200" -c:v h264_nvenc out.mp4
- Pad the input video to a 16:9 aspect ratio, filling with the color "blue":
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -i input.mp4 -vf "pad_cuda=w=ih*16/9/sar:h=ih:x=(ow-iw)/2:y=(oh-ih)/2:color=blue" -c:v h264_nvenc out.mp4
scale_cuda
Scale (resize) and convert (pixel format) the input video, using accelerated CUDA kernels. โจ Setting the output width and height works in the same way as for the scale filter.
The filter accepts the following options:
w,hโ set the output video dimension expression. Default value is the input dimension.
Allows for the same expressions as the scale filter.
interp_algoโ sets the algorithm used for scaling:nearestโ nearest neighbour. Used by default if input parameters match the desired output.bilinearโ bilinear.bicubicโ bicubic. This is the default.lanczosโ lanczos.
formatโ controls the output pixel format. By default, or if none is specified, the input pixel format is used.
The filter does not support converting between YUV and RGB pixel formats. ๐ญ
passthroughโ if set to0, every frame is processed, even if no conversion is necessary. This mode can be useful to use the filter as a buffer for a downstream frame-consumer that exhausts the limited decoder frame pool.
If set to 1, frames are passed through as-is if they match the desired output parameters. This is the default behaviour.
use_filtersโ if set to1, filter with a generic weight LUT instead of using fixed-function shader kernels. May be faster or slower depending on the hardware. A value ofauto(the default) enables this automatically when required for correct anti-aliasing when downscaling.paramโ algorithm-specific parameter.
Affects the curves of the bicubic algorithm.
force_original_aspect_ratio,force_divisible_byโ work the same as the identicalscalefilter options.reset_sarโ works the same as the identicalscalefilter option.
Examples
- Scale it to 720p while keeping the aspect ratio and making sure the output is
yuv420p๐
scale_cuda=-2:720:format=yuv420p
- Upscale to 4K with the nearest neighbour algorithm โ crunchy pixels, on purpose, no cap
scale_cuda=4096:2160:interp_algo=nearest
- Do literally zero conversion or scaling, just copy every input frame into freshly allocated ones โจ This one is a lifesaver when your filter-and-encode chain would otherwise drain the decoder's frame pool dry ๐
scale_cuda=passthrough=0
thumbnail_cuda ๐ผ๏ธ
Picks the most representative frame out of a run of consecutive frames, using CUDA. It's giving "choose the main character of this batch" energy ๐
Options it takes:
nโ sets the batch size of frames to analyze. Out of a set ofnframes it picks one, then moves on to the next batch ofnframes, all the way to the end. Default is100.
Heads up bestie ๐ โ since this filter keeps track of the whole frame sequence, a bigger n means higher memory usage, so a high value is not recommended. Be reasonable, ok?
Example ๐ธ
- Thumbnails get pulled from every
n=150-frame batch, one pick per batch. The chosen frames are then scaled withscale_cuda.
./ffmpeg -hwaccel cuda -hwaccel_output_format cuda -i ./input.mp4 -vf "thumbnail_cuda=150,scale_cuda=1920:1080,hwdownload,format=nv12" ./output/out%03d.png
yadif_cuda ๐ซ
Deinterlaces your input video with the yadif algorithm, except it's implemented in CUDA so it can slot right into a GPU-accelerated pipeline alongside nvdec and/or nvenc. Slay ๐ฅ
Parameters:
modeโ the interlacing mode to adopt. Accepts one of these:0,send_frameโ output one frame for each frame.1,send_fieldโ output one frame for each field.2,send_frame_nospatialโ likesend_frame, but it skips the spatial interlacing check.3,send_field_nospatialโ likesend_field, but it skips the spatial interlacing check.
Default value is send_frame.
parityโ the picture field parity assumed for the input interlaced video. Accepts one of these:0,tffโ assume the top field is first.1,bffโ assume the bottom field is first.-1,autoโ enable automatic detection of field parity.
Default value is auto. If the interlacing is unknown, or the decoder doesn't export that info, top field first gets assumed. ๐
deintโ which frames to deinterlace. Accepts one of these:0,allโ deinterlace all frames.1,interlacedโ only deinterlace frames marked as interlaced.
Default value is all.
โจ CUDA NPP โจ
Here's the rundown on the NVIDIA Performance Primitives (libnpp) video filters that are currently available ๐
Prerequisites, bestie, don't skip these:
- Install Nvidia CUDA Toolkit
- Install libnpp
To enable CUDA NPP filters:
- Configure FFmpeg with
--enable-nonfree --enable-libnpp.
scale_npp ๐
Uses the NVIDIA Performance Primitives (libnpp) to do scaling and/or pixel format conversion on CUDA video frames. Setting the output width and height works exactly the same way as it does for the scale filter.
Extra options it accepts:
formatโ the pixel format of the output CUDA frames. If you set it to the stringsame(which is the default), the input format is kept. Note that automatic format negotiation and conversion is not yet supported for hardware frames ๐ซinterp_algoโ the interpolation algorithm used for resizing. One of these:nnโ nearest neighbour.linearcubiccubic2p_bsplineโ 2-parameter cubic (B=1, C=0)cubic2p_catmullromโ 2-parameter cubic (B=0, C=1/2)cubic2p_b05c03โ 2-parameter cubic (B=1/2, C=3/10)superโ supersamplinglanczos
force_original_aspect_ratioโ lets the output video width or height decrease or increase when necessary, so the original aspect ratio stays intact. Possible values:disableโ scale the video as specified and turn this feature off.decreaseโ the output video dimensions get automatically decreased if needed.increaseโ the output video dimensions get automatically increased if needed.
A genuinely useful case for this: when you know a specific device's maximum allowed resolution, you can use this to cap the output video to it while retaining the aspect ratio. Example โ device A allows 1280x720 playback and your video is 1920x800. Using this option (set to decrease) and specifying 1280x720 on the command line makes the output 1280x533. Iconic ๐
Please note this is a different thing than specifying-1forworhโ you still need to specify the output resolution for this option to actually work. Don't come for me, that's just how it is ๐ญ
force_divisible_byโ makes sure both output dimensions, width and height, are divisible by the given integer when used together withforce_original_aspect_ratio. Works similarly to using-nin thewandhoptions.
This option respects whatever value you set for force_original_aspect_ratio, increasing or decreasing the resolution accordingly. Warning: the video's aspect ratio may get slightly modified. ๐ซถ
This one's handy if you need a video to fit within or exceed a defined resolution using force_original_aspect_ratio but you also have encoder restrictions on width or height divisibility.
reset_sarโ works the same as the identicalscalefilter option.evalโ specify when to evaluate the width and height expression. Accepts:initโ only evaluate expressions once during filter initialization, or when a command is processed.frameโ evaluate expressions for every incoming frame.
The values of the w and h options are expressions containing these constants:
in_w,in_hโ the input width and heightiw,ihโ same asin_wandin_h.out_w,out_hโ the output (scaled) width and heightow,ohโ same asout_wandout_haโ same asiw / ihsarโ input sample aspect ratiodarโ the input display aspect ratio. Calculated from(iw / ih) * sar.nโ the (sequential) number of the input frame, starting from 0. Only available witheval=frame.tโ the presentation timestamp of the input frame, expressed as a number of seconds. Only available witheval=frame.posโ the position (byte offset) of the frame in the input stream, or NaN if that info is unavailable and/or meaningless (for example, in the case of synthetic video). Only available witheval=frame. Deprecated, do not use. ๐
scale2ref_npp ๐
Uses the NVIDIA Performance Primitives (libnpp) to scale (resize) the input video based on a reference video.
Check out the scale_npp filter for the available options โ scale2ref_npp supports the same ones, but uses the reference video instead of the main input as its basis. It also supports these extra constants for the w and h options:
main_w,main_hโ the main input video's width and heightmain_aโ same asmain_w / main_hmain_sarโ the main input video's sample aspect ratiomain_dar,mdarโ the main input video's display aspect ratio. Calculated from(main_w / main_h) * main_sar.main_nโ the (sequential) number of the main input frame, starting from 0. Only available witheval=frame.main_tโ the presentation timestamp of the main input frame, expressed as a number of seconds. Only available witheval=frame.main_posโ the position (byte offset) of the frame in the main input stream, or NaN if that info is unavailable and/or meaningless (for example, in the case of synthetic video). Only available witheval=frame.
Examples ๐
- Scale a subtitle stream (
b) so it matches the main video (a) in size before overlaying:
'scale2ref_npp[b][a];[a][b]overlay_cuda'
- Scale a logo to 1/10th the height of a video while preserving its display aspect ratio:
[logo-in][video-in]scale2ref_npp=w=oh*mdar:h=ih/10[logo-out][video-out]
sharpen_npp ๐ชโจ
Uses the NVIDIA Performance Primitives (libnpp) to do image sharpening with border control.
Extra options it accepts:
border_typeโ the type of sampling used at frame borders. One of these:replicateโ replicate pixel values.
transpose_npp ๐ฆ
Transposes rows with columns in the input video and optionally flips it. For more in-depth examples, peep the transpose video filter โ it shares mostly the same options.
Parameters:
dirโ specify the transposition direction.
Can be one of these:
cclock_flipโ rotate 90 degrees counterclockwise and vertically flip. (default)clockโ rotate 90 degrees clockwise.cclockโ rotate 90 degrees counterclockwise.clock_flipโ rotate 90 degrees clockwise and vertically flip.
passthroughโ don't apply the transposition if the input geometry already matches the one specified by this value. Accepts:noneโ always apply transposition. (default)portraitโ preserve portrait geometry (whenheight >= width).landscapeโ preserve landscape geometry (whenwidth >= height).
๐ OPENCL VIDEO FILTERS ๐
And here's the breakdown of the OpenCL video filters that are currently available ๐
To enable compilation of these filters you need to configure FFmpeg with --enable-opencl.
Running OpenCL filters means you gotta initialize a hardware device and pass that device to every filter in any filter graph. Periodt.
-init_hw_device opencl[=name][:device[,key=value...]]โ initialise a new hardware device of typeopenclcalled name, using the given device parameters.-filter_hw_device nameโ pass the hardware device called name to all filters in any filter graph.
For more detailed info, see <https://www.ffmpeg.org/ffmpeg.html#Advanced-Video-options>
- Example of choosing the first device on the second platform and running the
avgblur_openclfilter with default parameters on it ๐
-init_hw_device opencl=gpu:1.0 -filter_hw_device gpu -i INPUT -vf "hwupload, avgblur_opencl, hwdownload" OUTPUT
okay so real talk, bestie: OpenCL filters can't just reach into normal memory and grab frame data. All frame data needs to be uploaded first โ that's hwupload โ to hardware surfaces connected to the appropriate device before being used, and then downloaded back to normal memory with hwdownload. ๐
Also note that hwupload will upload to a surface with the same layout as the software frame, so it may be necessary to add a format filter immediately before to get the input into the right format. And hwdownload does not support all formats on the output โ it may be necessary to insert an additional format filter immediately following in the graph to get the output in a supported format. No cap.
avgblur_opencl ๐
Apply average blur filter. It's giving soft-focus main character energy.
The filter accepts the following options:
sizeXโ Set horizontal radius size. Range is[1, 1024]and default value is1.planesโ Set which planes to filter. Default value is0xf, by which all planes are processed.sizeYโ Set vertical radius size. Range is[1, 1024]and default value is0. If zero, thesizeXvalue will be used.
Example โจ
- Apply average blur filter with horizontal and vertical size of
3, setting each pixel of the output to the average value of the7x7region centered on it in the input. For pixels on the edges of the image, the region does not extend beyond the image boundaries, and so out-of-range coordinates are not used in the calculations.
-i INPUT -vf "hwupload, avgblur_opencl=3, hwdownload" OUTPUT
boxblur_opencl ๐
Apply a boxblur algorithm to the input video.
It accepts the following parameters:
luma_radius,lrluma_power,lpchroma_radius,crchroma_power,cpalpha_radius,aralpha_power,ap
A description of the accepted options follows.
luma_radius,lr,chroma_radius,cr,alpha_radius,arโ Set an expression for the box radius in pixels used for blurring the corresponding input plane.
The radius value must be a non-negative number, and must not be greater than the value of the expression min(w,h)/2 for the luma and alpha planes, and of min(cw,ch)/2 for the chroma planes.
Default value for luma_radius is 2. If not specified, chroma_radius and alpha_radius default to the corresponding value set for luma_radius.
The expressions can contain the following constants:
w,hโ The input width and height in pixels.cw,chโ The input chroma image width and height in pixels.hsub,vsubโ The horizontal and vertical chroma subsample values. For example, for the pixel formatyuv422p,hsubis2andvsubis1.
luma_power,lp,chroma_power,cp,alpha_power,apโ Specify how many times the boxblur filter is applied to the corresponding plane.
Default value for luma_power is 2. If not specified, chroma_power and alpha_power default to the corresponding value set for luma_power.
A value of 0 will disable the effect. ๐
Examples ๐ฆ
Apply boxblur filter, setting each pixel of the output to the average value of box-radiuses luma_radius, chroma_radius, alpha_radius for each plane respectively. The filter will apply luma_power, chroma_power, alpha_power times onto the corresponding plane. For pixels on the edges of the image, the radius does not extend beyond the image boundaries, and so out-of-range coordinates are not used in the calculations.
- Apply a boxblur filter with the luma, chroma, and alpha radius set to
2and luma, chroma, and alpha power set to3. The filter will run3times with box-radius set to2for every plane of the image.
-i INPUT -vf "hwupload, boxblur_opencl=luma_radius=2:luma_power=3, hwdownload" OUTPUT
-i INPUT -vf "hwupload, boxblur_opencl=2:3, hwdownload" OUTPUT
- Apply a boxblur filter with luma radius set to
2,luma_powerto1,chroma_radiusto4,chroma_powerto5,alpha_radiusto3andalpha_powerto7.
For the luma plane, a 2x2 box radius will be run once.
For the chroma plane, a 4x4 box radius will be run 5 times.
For the alpha plane, a 3x3 box radius will be run 7 times.
-i INPUT -vf "hwupload, boxblur_opencl=2:1:4:5:3:7, hwdownload" OUTPUT
colorkey_opencl ๐
RGB colorspace color keying.
The filter accepts the following options:
colorโ The color which will be replaced with transparency.similarityโ Similarity percentage with the key color.
0.01 matches only the exact key color, while 1.0 matches everything.
blendโ Blend percentage.
0.0 makes pixels either fully transparent, or not transparent at all.
Higher values result in semi-transparent pixels, with a higher transparency the more similar the pixels color is to the key color.
Examples ๐ธ
- Make every semi-green pixel in the input transparent with some slight blending:
-i INPUT -vf "hwupload, colorkey_opencl=green:0.3:0.1, hwdownload" OUTPUT
convolution_opencl ๐ฅ
Apply convolution of 3x3, 5x5, 7x7 matrix.
The filter accepts the following options:
0m,1m,2m,3mโ Set matrix for each plane. Matrix is sequence of9,25or49signed numbers. Default value for each plane is0 0 0 0 1 0 0 0 0.0rdiv,1rdiv,2rdiv,3rdivโ Set multiplier for calculated value for each plane. If unset or0, it will be sum of all matrix elements. The option value must be a float number greater or equal to0.0. Default value is1.0.0bias,1bias,2bias,3biasโ Set bias for each plane. This value is added to the result of the multiplication. Useful for making the overall image brighter or darker. The option value must be a float number greater or equal to0.0. Default value is0.0.
Examples ๐
- Apply sharpen:
-i INPUT -vf "hwupload, convolution_opencl=0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0, hwdownload" OUTPUT
- Apply blur:
-i INPUT -vf "hwupload, convolution_opencl=1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1/9:1/9:1/9:1/9, hwdownload" OUTPUT
- Apply edge enhance:
-i INPUT -vf "hwupload, convolution_opencl=0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:5:1:1:1:0:128:128:128, hwdownload" OUTPUT
- Apply edge detect:
-i INPUT -vf "hwupload, convolution_opencl=0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:5:5:5:1:0:128:128:128, hwdownload" OUTPUT
- Apply laplacian edge detector which includes diagonals:
-i INPUT -vf "hwupload, convolution_opencl=1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:5:5:5:1:0:128:128:0, hwdownload" OUTPUT
- Apply emboss:
-i INPUT -vf "hwupload, convolution_opencl=-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2, hwdownload" OUTPUT
erosion_opencl ๐
Apply erosion effect to the video.
This filter replaces the pixel by the local(3x3) minimum.
It accepts the following options:
threshold0,threshold1,threshold2,threshold3โ Limit the maximum change for each plane. Range is[0, 65535]and default value is65535. If0, plane will remain unchanged.coordinatesโ Flag which specifies the pixel to refer to. Range is[0, 255]and default value is255, i.e. all eight pixels are used.
Flags to local 3x3 coordinates region centered on x:
1 2 3
4 x 5
6 7 8
Example ๐ซถ
- Apply erosion filter with
threshold0set to30,threshold1set40,threshold2set to50andcoordinatesset to231, setting each pixel of the output to the local minimum between pixels:1,2,3,6,7,8of the3x3region centered on it in the input. If the difference between input pixel and local minimum is more then threshold of the corresponding plane, output pixel will be set to input pixel - threshold of corresponding plane.
-i INPUT -vf "hwupload, erosion_opencl=30:40:50:coordinates=231, hwdownload" OUTPUT
deshake_opencl ๐ฆ
Feature-point based video stabilization filter.
The filter accepts the following options:
tripodโ Simulates a tripod by preventing any camera movement whatsoever from the original frame. Defaults to0.debugโ Whether or not additional debug info should be displayed, both in the processed output and in the console.
Note that in order to see console debug output you will also need to pass -v verbose to ffmpeg.
Viewing point matches in the output video is only supported for RGB input.
Defaults to 0.
adaptive_cropโ Whether or not to do a tiny bit of cropping at the borders to cut down on the amount of mirrored pixels.
Defaults to 1.
refine_featuresโ Whether or not feature points should be refined at a sub-pixel level.
This can be turned off for a slight performance gain at the cost of precision.
Defaults to 1.
smooth_strengthโ The strength of the smoothing applied to the camera path from0.0to1.0.
1.0 is the maximum smoothing strength while values less than that result in less smoothing.
0.0 causes the filter to adaptively choose a smoothing strength on a per-frame basis.
Defaults to 0.0.
smooth_window_multiplierโ Controls the size of the smoothing window (the number of frames buffered to determine motion information from).
The size of the smoothing window is determined by multiplying the framerate of the video by this number.
Acceptable values range from 0.1 to 10.0.
Larger values increase the amount of motion data available for determining how to smooth the camera path, potentially improving smoothness, but also increase latency and memory usage.
Defaults to 2.0.
Examples โญ
- Stabilize a video with a fixed, medium smoothing strength:
-i INPUT -vf "hwupload, deshake_opencl=smooth_strength=0.5, hwdownload" OUTPUT
- Stabilize a video with debugging (both in console and in rendered video):
-i INPUT -filter_complex "[0:v]format=rgba, hwupload, deshake_opencl=debug=1, hwdownload, format=rgba, format=yuv420p" -v verbose OUTPUT
dilation_opencl ๐
Apply dilation effect to the video.
This filter replaces the pixel by the local(3x3) maximum.
It accepts the following options:
okay so the last dilation_opencl dials are these:
threshold0โ caps the max change for plane 0. Range is[0, 65535], default is65535. If it's0, that plane stays unchanged, periodt.threshold1โ same thing but for plane 1. Range is[0, 65535], default is65535. If it's0, plane 1 remains untouched.threshold2โ plane 2's max-change cap. Range is[0, 65535], default is65535. Set it to0and plane 2 will remain unchanged.threshold3โ plane 3's max-change cap. Range is[0, 65535], default is65535.0means plane 3 remains unchanged.coordinatesโ tells it which pixel to refer to. Range is[0, 255], default is255, which means all eight pixels are used. Flags to local 3x3 coordinates region centered onx:
1 2 3
4 x 5
6 7 8
Example
Apply dilation filter with threshold0 set to 30, threshold1 set 40, threshold2 set to 50 and coordinates set to 231, setting each pixel of the output to the local maximum between pixels: 1, 2, 3, 6, 7, 8 of the 3x3 region centered on it in the input. If the difference between input pixel and local maximum is more than threshold of the corresponding plane, output pixel will be set to input pixel + threshold of corresponding plane.
-i INPUT -vf "hwupload, dilation_opencl=30:40:50:coordinates=231, hwdownload" OUTPUT
nlmeans_opencl
Non-local Means denoise filter through OpenCL, this filter accepts same options as nlmeans. easy win โจ
overlay_opencl
Overlay one video on top of another.
It takes two inputs and has one output. The first input is the "main" video on which the second input is overlaid. This filter requires same memory layout for all the inputs. So, format conversion may be needed.
The filter accepts the following options:
xโ Set the x coordinate of the overlaid video on the main video. Default value is0.yโ Set the y coordinate of the overlaid video on the main video. Default value is0.
Examples
- Overlay an image
LOGOat the top-left corner of theINPUTvideo. Both inputs areyuv420pformat.
-i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuv420p, hwupload[b], [a][b]overlay_opencl, hwdownload" OUTPUT
- The inputs have same memory layout for color channels, the overlay has additional alpha plane, like
INPUTisyuv420p, and theLOGOisyuva420p.
-i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuva420p, hwupload[b], [a][b]overlay_opencl, hwdownload" OUTPUT
pad_opencl
Add paddings to the input image, and place the original input at the provided x, y coordinates.
It accepts the following options:
width,w,height,hโ Specify an expression for the size of the output image with the paddings added. If the value forwidthorheightis0, the corresponding input size is used for the output. Thewidthexpression can reference the value set by theheightexpression, and vice versa. The default value ofwidthandheightis0.x,yโ Specify the offsets to place the input image at within the padded area, with respect to the top/left border of the output image. Thexexpression can reference the value set by theyexpression, and vice versa. The default value ofxandyis0. Ifxoryevaluate to a negative number, they'll be changed so the input image is centered on the padded area.colorโ Specify the color of the padded area. For the syntax of this option, check theColorsection in theffmpeg-utilsmanual.aspectโ Pad to an aspect instead to a resolution.
The value for the width, height, x, and y options are expressions containing the following constants:
in_w,in_hโ The input video width and height.iw,ihโ These are the same asin_wandin_h.out_w,out_hโ The output width and height (the size of the padded area), as specified by thewidthandheightexpressions.ow,ohโ These are the same asout_wandout_h.x,yโ The x and y offsets as specified by thexandyexpressions, orNANif not yet specified.aโ same asiw / ihsarโ input sample aspect ratiodarโ input display aspect ratio, it is the same as(iw / ih) * sar
prewitt_opencl
Apply the Prewitt operator (https://en.wikipedia.org/wiki/Prewitt_operator) to input video stream.
The filter accepts the following option:
planesโ Set which planes to filter. Default value is0xf, by which all planes are processed.scaleโ Set value which will be multiplied with filtered result. Range is[0.0, 65535]and default value is1.0.deltaโ Set value which will be added to filtered result. Range is[-65535, 65535]and default value is0.0.
Example
- Apply the Prewitt operator with
scaleset to2anddeltaset to10.
-i INPUT -vf "hwupload, prewitt_opencl=scale=2:delta=10, hwdownload" OUTPUT
program_opencl
Filter video using an OpenCL program.
sourceโ OpenCL program source file.kernelโ Kernel name in program.inputsโ Number of inputs to the filter. Defaults to1.size,sโ Size of output frames. Defaults to the same as the first input.
The program_opencl filter also supports the framesync options.
The program source file must contain a kernel function with the given name, which will be run once for each plane of the output. Each run on a plane gets enqueued as a separate 2D global NDRange with one work-item for each pixel to be generated. The global ID offset for each work-item is therefore the coordinates of a pixel in the destination image.
The kernel function needs to take the following arguments:
- Destination image,
__write_only image2d_t.
This image will become the output; the kernel should write all of it.
- Frame index,
unsigned int.
This is a counter starting from zero and increasing by one for each frame.
- Source images,
__read_only image2d_t.
These are the most recent images on each input. The kernel may read from them to generate the output, but they can't be written to.
Example programs:
- Copy the input to the output (output must be the same size as the input).
__kernel void copy(__write_only image2d_t destination,
unsigned int index,
__read_only image2d_t source)
{
const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE;
int2 location = (int2)(get_global_id(0), get_global_id(1));
float4 value = read_imagef(source, sampler, location);
write_imagef(destination, location, value);
}
- Apply a simple transformation, rotating the input by an amount increasing with the index counter. Pixel values are linearly interpolated by the sampler, and the output need not have the same dimensions as the input.
__kernel void rotate_image(__write_only image2d_t dst,
unsigned int index,
__read_only image2d_t src)
{
const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
CLK_FILTER_LINEAR);
float angle = (float)index / 100.0f;
float2 dst_dim = convert_float2(get_image_dim(dst));
float2 src_dim = convert_float2(get_image_dim(src));
float2 dst_cen = dst_dim / 2.0f;
float2 src_cen = src_dim / 2.0f;
int2 dst_loc = (int2)(get_global_id(0), get_global_id(1));
float2 dst_pos = convert_float2(dst_loc) - dst_cen;
float2 src_pos = {
cos(angle) * dst_pos.x - sin(angle) * dst_pos.y,
sin(angle) * dst_pos.x + cos(angle) * dst_pos.y
};
src_pos = src_pos * src_dim / dst_dim;
float2 src_loc = src_pos + src_cen;
if (src_loc.x < 0.0f || src_loc.y < 0.0f ||
src_loc.x > src_dim.x || src_loc.y > src_dim.y)
write_imagef(dst, dst_loc, 0.5f);
else
write_imagef(dst, dst_loc, read_imagef(src, sampler, src_loc));
}
- Blend two inputs together, with the amount of each input used varying with the index counter.
__kernel void blend_images(__write_only image2d_t dst,
unsigned int index,
__read_only image2d_t src1,
__read_only image2d_t src2)
{
const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
CLK_FILTER_LINEAR);
float blend = (cos((float)index / 50.0f) + 1.0f) / 2.0f;
int2 dst_loc = (int2)(get_global_id(0), get_global_id(1));
int2 src1_loc = dst_loc * get_image_dim(src1) / get_image_dim(dst);
int2 src2_loc = dst_loc * get_image_dim(src2) / get_image_dim(dst);
float4 val1 = read_imagef(src1, sampler, src1_loc);
float4 val2 = read_imagef(src2, sampler, src2_loc);
write_imagef(dst, dst_loc, val1 * blend + val2 * (1.0f - blend));
}
remap_opencl
Remap pixels using 2nd: Xmap and 3rd: Ymap input video stream.
Destination pixel at position (X, Y) will be picked from source (x, y) position where x = Xmap(X, Y) and y = Ymap(X, Y). If mapping values are out of range, zero value for pixel will be used for destination pixel.
Xmap and Ymap input video streams must be of same dimensions. Output video stream will have Xmap/Ymap video stream dimensions. Xmap and Ymap input video streams are 32bit float pixel format, single channel.
interpโ Specify interpolation used for remapping of pixels. Allowed values arenearandlinear. Default value islinear.fillโ Specify the color of the unmapped pixels. For the syntax of this option, check theColorsection in theffmpeg-utilsmanual. Default color isblack.
roberts_opencl
Apply the Roberts cross operator (https://en.wikipedia.org/wiki/Roberts_cross) to input video stream.
The filter accepts the following option:
planesโ Set which planes to filter. Default value is0xf, by which all planes are processed.scaleโ Set value which will be multiplied with filtered result. Range is[0.0, 65535]and default value is1.0.deltaโ Set value which will be added to filtered result. Range is[-65535, 65535]and default value is0.0.
Example
- Apply the Roberts cross operator with
scaleset to2anddeltaset to10
-i INPUT -vf "hwupload, roberts_opencl=scale=2:delta=10, hwdownload" OUTPUT
๐ sobel_opencl
This one runs the Sobel operator over your input video stream โ edge-detection classic, iykyk. (The Wikipedia link, if you wanna read up: https://en.wikipedia.org/wiki/Sobel_operator.)
It takes these options:
planesโ picks which planes get filtered. Default is0xf, which means every plane gets the treatment ๐scaleโ the value that gets multiplied with the filtered result. Range is[0.0, 65535], default is1.0.deltaโ the value added onto the filtered result. Range is[-65535, 65535], default is0.0.
โจ Example
- So here's the vibe: sobel operator with
scaleset to2anddeltaset to10, slay:
-i INPUT -vf "hwupload, sobel_opencl=scale=2:delta=10, hwdownload" OUTPUT
๐ tonemap_opencl
HDR (PQ/HLG) โ SDR conversion with tone-mapping. Basically your overly-bright video gets a little reality check โจ
It accepts these params:
tonemapโ picks the tone-mapping operator. Same as thetonemapoption intonemap.paramโ tunes the tone-mapping algorithm. Same as theparamoption intonemap.desatโ desaturates highlights that go past this brightness level. The higher you set it, the more color info gets preserved. It's the thing that stops super-highlights from looking like a blown-out crime scene, by (smoothly) fading them into white instead. Makes images feel way more natural, at the cost of losing info about out-of-range colors.
Default is 0.5, and ngl the algorithm here is a lil different from the CPU version of tonemap at the moment. Setting it to 0.0 disables the option entirely.
thresholdโ the tonemapping algorithm gets fine-tuned per scene, and this threshold is how it detects whether the scene changed. If the distance between the current frame's average brightness and the current running average exceeds the threshold, it re-calculates the scene average and peak brightness. Default is0.2.formatโ sets the output pixel format.
Formats supported rn are:
p010nv12
range,rโ sets the output color range.
Possible values:
tv/mpegpc/jpeg
Default is same as input.
primaries,pโ sets the output color primaries.
Possible values:
bt709bt2020
Default is same as input.
transfer,tโ sets the output transfer characteristics.
Possible values:
bt709bt2020
Default is bt709.
matrix,mโ sets the output colorspace matrix.
Possible values:
bt709bt2020
Default is same as input.
โจ Example
- Convert an HDR (PQ/HLG) video to bt2020-transfer-characteristic
p010format using thelinearoperator. Obsessed with this one:
-i INPUT -vf "format=p010,hwupload,tonemap_opencl=t=bt2020:tonemap=linear:format=p010,hwdownload,format=p010" OUTPUT
๐ฆ unsharp_opencl
Sharpen or blur your input video. Pick your fighter ๐
It accepts these parameters:
luma_msize_x,lxโ luma matrix horizontal size. Range[1, 23], default5.luma_msize_y,lyโ luma matrix vertical size. Range[1, 23], default5.luma_amount,laโ luma effect strength. Range[-10, 10], default1.0.
Negative values blur the input, positive values sharpen it, and zero disables the effect completely.
chroma_msize_x,cxโ chroma matrix horizontal size. Range[1, 23], default5.chroma_msize_y,cyโ chroma matrix vertical size. Range[1, 23], default5.chroma_amount,caโ chroma effect strength. Range[-10, 10], default0.0.
Same deal: negative blurs, positive sharpens, zero = effect off.
Every single parameter is optional and defaults to the equivalent of the string '5:5:1.0:5:5:0.0'. Cute, right?
โจ Examples
- Strong luma sharpen, go off:
-i INPUT -vf "hwupload, unsharp_opencl=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5, hwdownload" OUTPUT
- Strong blur on both luma and chroma:
-i INPUT -vf "hwupload, unsharp_opencl=7:7:-2:7:7:-2, hwdownload" OUTPUT
๐ง xfade_opencl
Cross-fades two videos with a custom transition effect, using OpenCL. Main character energy for your cuts ๐ฅ
It accepts these options:
transitionโ sets one of the possible transition effects:customโ selects the custom transition effect; the actual transition description gets picked from thesourceandkerneloptions.fadewipeleftwiperightwipeupwipedownslideleftsliderightslideupslidedown
Default transition is fade.
sourceโ the OpenCL program source file for a custom transition.kernelโ sets the name of the kernel to use for the custom transition from the program source file.durationโ sets the duration of the video transition.offsetโ sets the time the transition starts, relative to the first video.
Heads up bestie: the program source file must contain a kernel function with the given name, and that function gets run once for each plane of the output. Each run on a plane is enqueued as a separate 2D global NDRange with one work-item for each pixel to be generated. So the global ID offset for each work-item is literally the coordinates of a pixel in the destination image. No cap.
The kernel function needs to take these arguments:
- Destination image,
__write_only image2d_t.
This image becomes the output โ the kernel should write all of it.
- First Source image,
__read_only image2d_t. Second Source image,__read_only image2d_t.
These are the most recent images on each input. The kernel can read from them to generate the output, but writing to them? Not happening, sorry.
- Transition progress,
float. This value is always between0and1inclusive.
โจ Example programs
- Apply a dots curtain transition effect โ this is the iconic one ๐
__kernel void blend_images(__write_only image2d_t dst,
__read_only image2d_t src1,
__read_only image2d_t src2,
float progress)
{
const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
CLK_FILTER_LINEAR);
int2 p = (int2)(get_global_id(0), get_global_id(1));
float2 rp = (float2)(get_global_id(0), get_global_id(1));
float2 dim = (float2)(get_image_dim(src1).x, get_image_dim(src1).y);
rp = rp / dim;
float2 dots = (float2)(20.0, 20.0);
float2 center = (float2)(0,0);
float2 unused;
float4 val1 = read_imagef(src1, sampler, p);
float4 val2 = read_imagef(src2, sampler, p);
bool next = distance(fract(rp * dots, &unused), (float2)(0.5, 0.5)) < (progress / distance(rp, center));
write_imagef(dst, p, next ? val1 : val2);
}
โจ VAAPI VIDEO FILTERS โจ
Okay bestie, so VAAPI video filters are these iconic little guys that usually team up with a VAAPI decoder and a VAAPI encoder. Like, they're a whole squad that shows up together. ๐ Below is the full rundown of every VAAPI video filter, no gatekeeping.
To get these filters to even compile, you gotta configure FFmpeg with --enable-vaapi. That's the vibe check for the build step, fr.
And to actually use vaapi filters, you need to set up the vaapi device correctly first. No device, no slay. For more info, please read https://trac.ffmpeg.org/wiki/Hardware/VAAPI โ go read it, iykyk. ๐ฆ
๐ overlay_vaapi
Overlay one video right on top of another. Main character on top of main character, literally.
It takes two inputs and has exactly one output. The first input is the "main" video โ the one getting overlaid โ and the second input is the one doing the overlaying. ๐
The filter accepts the following options:
x,yโ Set expressions for the x and y coordinates of the overlaid video on the main video. Default value is0for both expressions.w,hโ Set expressions for the width and height of the overlaid video on the main video. Default values areoverlay_iwforwandoverlay_ih*w/overlay_iwforh.
The expressions can contain the following parameters:
main_w,W/main_h,Hโ The main input width and height.overlay_iw/overlay_ihโ The overlay input width and height.overlay_w,w/overlay_h,hโ The overlay output width and height.overlay_x,x/overlay_y,yโ Position of the overlay layer inside of main.
More options, because of course there are:
alphaโ Set transparency of overlaid video. Allowed range is0.0to1.0. Higher value means lower transparency. Default value is1.0. (Yes, that's backwards from what your brain wants it to be โ higher alpha = less see-through. Note it and move on. ๐)eof_actionโ See framesync.shortestโ See framesync.repeatlastโ See framesync.
This filter also supports the framesync options. ๐ซถ
๐ธ Examples
- Overlay an image
LOGOat the top-left corner of theINPUTvideo. Both inputs for this filter areyuv420pformat.
-i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuv420p, hwupload[b], [a][b]overlay_vaapi" OUTPUT
- Overlay an image
LOGOat the offset(200, 100)from the top-left corner of theINPUTvideo. The inputs have same memory layout for color channels, the overlay has additional alpha plane, likeINPUTisyuv420p, and theLOGOisyuva420p.
-i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuva420p, hwupload[b], [a][b]overlay_vaapi=x=200:y=100:w=400:h=300:alpha=1.0, hwdownload, format=nv12" OUTPUT
๐ฆ tonemap_vaapi
Perform HDR-to-SDR or HDR-to-HDR tone-mapping. It currently only accepts HDR10 as input โ so if you roll up with something else, it's not gonna work, bestie. ๐ญ
It accepts the following parameters:
formatโ Specify the output pixel format. Default isnv12for HDR-to-SDR tone-mapping andp010for HDR-to-HDR tone-mapping.primaries,pโ Set the output color primaries. Default isbt709for HDR-to-SDR tone-mapping and same as input for HDR-to-HDR tone-mapping.transfer,tโ Set the output transfer characteristics. Default isbt709for HDR-to-SDR tone-mapping and same as input for HDR-to-HDR tone-mapping.matrix,mโ Set the output colorspace matrix. Default isbt709for HDR-to-SDR tone-mapping and same as input for HDR-to-HDR tone-mapping.displayโ Set the output mastering display colour volume. It is given by a|-separated list of two values, two values are space separated. It set display primaries x & y in G, B, R order, then white point x & y, the nominal minimum & maximum display luminances. HDR-to-HDR tone-mapping will be performed when this option is set. โจlightโ Set the output content light level information. It accepts 2 space-separated values, the first input is the maximum light level and the second input is the maximum average light level. It is ignored for HDR-to-SDR tone-mapping, and optional for HDR-to-HDR tone-mapping.
๐ Example
- Convert HDR(HDR10) video to bt2020-transfer-characteristic p010 format
tonemap_vaapi=format=p010:t=bt2020-10
- Convert HDR video to HDR video
tonemap_vaapi=display=7500\ 3000|34000\ 16000|13250\ 34500|15635\ 16450|500\ 10000000
๐ง hstack_vaapi
Stack input videos horizontally. Side by side, bestie. ๐
This is the VA-API variant of the hstack filter, and here's the cute part โ each input stream may have different height, and this filter will scale down/up each input stream while keeping the original aspect. Flexible and polite. ๐
It accepts the following options:
inputsโ Seehstack.shortestโ Seehstack.heightโ Set height of output. If set to0, this filter will set height of output to height of the first input stream. Default value is0.
๐ vstack_vaapi
Stack input videos vertically. Same energy as above but stacked up-and-down instead. ๐ซถ
This is the VA-API variant of the vstack filter, each input stream may have different width, this filter will scale down/up each input stream while keeping the original aspect.
It accepts the following options:
inputsโ Seevstack.shortestโ Seevstack.widthโ Set width of output. If set to0, this filter will set width of output to width of the first input stream. Default value is0.
โญ xstack_vaapi
Stack video inputs into a custom layout. This one is the artsy one โ you decide where everything goes. ๐
This is the VA-API variant of the xstack filter, each input stream may have different size, this filter will scale down/up each input stream to the given output size, or the size of the first input stream.
It accepts the following options:
inputsโ Seexstack.shortestโ Seexstack.layoutโ Seexstack. Moreover, this permits the user to supply output size for each input stream.
xstack_vaapi=inputs=4:layout=0_0_1920x1080|0_h0_1920x1080|w0_0_1920x1080|w0_h0_1920x1080
gridโ Seexstack.grid_tile_sizeโ Set output size for each input stream whengridis set. If this option is not set, this filter will set output size by default to the size of the first input stream. For the syntax of this option, check the"Video size"section in the ffmpeg-utils manual.fillโ Seexstack.
๐ pad_vaapi
Add paddings to the input image, and place the original input at the provided x, y coordinates. It's giving scrapbook page with a cute border. ๐
It accepts the following options:
width,w/height,hโ Specify an expression for the size of the output image with the paddings added. If the value forwidthorheightis0, the corresponding input size is used for the output.
The width expression can reference the value set by the height expression, and vice versa.
The default value of width and height is 0.
x,yโ Specify the offsets to place the input image at within the padded area, with respect to the top/left border of the output image.
The x expression can reference the value set by the y expression, and vice versa.
The default value of x and y is 0.
If x or y evaluate to a negative number, they'll be changed so the input image is centered on the padded area. ๐ฏ
colorโ Specify the color of the padded area. For the syntax of this option, check the"Color"section in the ffmpeg-utils manual.aspectโ Pad to an aspect instead to a resolution.
The value for the width, height, x, and y options are expressions containing the following constants:
in_w/in_hโ The input video width and height.iw/ihโ These are the same asin_wandin_h.out_w/out_hโ The output width and height (the size of the padded area), as specified by thewidthandheightexpressions.ow/ohโ These are the same asout_wandout_h.x/yโ Thexandyoffsets as specified by thexandyexpressions, orNANif not yet specified.aโ same asiw / ihsarโ input sample aspect ratiodarโ input display aspect ratio, it is the same as(iw / ih) * sar
๐ drawbox_vaapi
Draw a colored box on the input image. Arts and crafts era, fr fr. ๐จ
It accepts the following parameters:
x,yโ The expressions which specify the top left corner coordinates of the box. It defaults to0.width,w/height,hโ The expressions which specify the width and height of the box; if0they are interpreted as the input width and height. It defaults to0.color,cโ Specify the color of the box to write. For the general syntax of this option, check the"Color"section in the ffmpeg-utils manual.thickness,tโ The expression which sets the thickness of the box edge. A value offillwill create a filled box. Default value is3. See below for the list of accepted constants.replaceโ With value1, the pixels of the painted box will overwrite the video's color and alpha pixels. Default is0, which composites the box onto the input video.
The parameters for x, y, w and h and t are expressions containing the following constants:
in_h,ih/in_w,iwโ The input width and height.x/yโ The x and y offset coordinates where the box is drawn.w/hโ The width and height of the drawn box.tโ The thickness of the drawn box.
๐ Examples
- Draw a black box around the edge of the input image:
drawbox
- Draw a box with color red and an opacity of 50%:
drawbox=10:20:200:60:red@0.5
The previous example can be specified as:
drawbox=x=10:y=20:w=200:h=60:color=red@0.5
- Fill the box with pink color:
drawbox=x=10:y=10:w=100:h=100:color=pink@0.5:t=fill
- Draw a 2-pixel red 2.40:1 mask:
drawbox=x=-t:y=0.5*(ih-iw/2.4)-t:w=iw+t*2:h=iw/2.4+t*2:t=2:c=red
VIDEOTOOLBOX VIDEO FILTERS ๐โจ
Okay bestie, here's the tea on the VideoToolbox video filters that are currently available. ๐
VideoToolbox filter depends on VideoToolbox framework, and it's auto detected when you build ffmpeg for an Apple platform such as macOS. If autodetect is off for some reason, just add --enable-videotoolbox to configure and you're so back. ๐ซถ
scale_vt ๐
It scales and converts the color parameters using VTPixelTransferSession. Two jobs, one filter, main character energy fr.
The filter accepts the following options:
whโ Set the output video dimension expression. Default value is the input dimension. (so if you don't say anything, it just matches what came in ๐ )color_matrixโ Set the output colorspace matrix.color_primariesโ Set the output color primaries.color_transferโ Set the output transfer characteristics.
Examples ๐ธ
- Perform HDR to SDR conversion, and scale to half size of input ๐ฅ
ffmpeg -hwaccel videotoolbox \
-hwaccel_output_format videotoolbox_vld \
-i hdr.mov \
-c:v hevc_videotoolbox \
-profile:v main \
-b:v 3M \
-vf scale_vt=w=iw/2:h=ih/2:color_matrix=bt709:color_primaries=bt709:color_transfer=bt709 \
-c:a copy \
-tag:v hvc1 \
sdr.mp4
transpose_vt ๐ฆ
This one transposes rows with columns in the input video and optionally flips it. For more in depth examples, go peek at the transpose video filter โ it shares mostly the same options, iykyk. ๐
It accepts the following parameters:
dirโ Specify the transposition direction.
Can assume the following values:
cclock_flipโ Rotate by 90 degrees counterclockwise and vertically flip. (default) โญclockโ Rotate by 90 degrees clockwise.cclockโ Rotate by 90 degrees counterclockwise.clock_flipโ Rotate by 90 degrees clockwise and vertically flip.hflipโ Flip the input video horizontally.vflipโ Flip the input video vertically.
passthroughโ Do not apply the transposition if the input geometry matches the one specified by the specified value. It accepts the following values:noneโ Always apply transposition. (default)portraitโ Preserve portrait geometry (whenheight >= width).landscapeโ Preserve landscape geometry (whenwidth >= height).
ngl, passthrough is lowkey the icon here โ it's literally the "read the room before you rotate" option ๐๐ซถ
๐ VULKAN VIDEO FILTERS ๐
okay so this is the Vulkan filter fam โ here's the whole rundown of what's currently available ๐
real talk first: to even compile these filters you gotta configure FFmpeg with --enable-vulkan and either --enable-libglslang or --enable-libshaderc. no shortcuts, bestie ๐ซถ
and running Vulkan filters isn't a plug-and-play vibe โ you need to initialize a hardware device and then hand that device to every filter in the filter graph โจ
-init_hw_device vulkan[=name][:device[,key=value...]]โ inits a brand-new hardware device of typevulkancalled name, using the device params and options you pass inkey=value. The supported options are:debugโ flips validation layers ON if you set it to1.linear_imagesโ allocates linear images. Does NOT apply to decoding, jsyk.disable_multiplaneโ disables multiplane images. Also does NOT apply to decoding.avoid_host_importโ skips the dynamic host memory imports and instead goes for a regularmemcpy()into a buffer that was mapped earlier.
-filter_hw_device nameโ passes the hardware device called name to all the filters in any filter graph. literally all of them ๐
for the deep lore, see https://www.ffmpeg.org/ffmpeg.html#Advanced-Video-options
- ๐ example of grabbing the first device and running the
nlmeans_vulkanfilter on it with default params:
-init_hw_device vulkan=vk:0 -filter_hw_device vk -i INPUT -vf "hwupload,nlmeans_vulkan,hwdownload" OUTPUT
โ ๏ธ important vibe check: Vulkan filters can't touch frame data sitting in normal memory ๐ญ so all frame data has to be uploaded (hwupload) to hardware surfaces attached to the right device before use, and then downloaded (hwdownload) back into normal memory afterwards. Also note thathwuploaduploads to a frame with the same layout as the software frame โ so you might need to slap aformatfilter immediately before it to get the input into the right format. Andhwdownloaddoesn't support all formats on the output โ usually you gotta insert anotherformatfilter right after it in the graph so the output lands in a supported format. plan accordingly bestie ๐ฆ
๐ซ avgblur_vulkan
applies an average blur filter, implemented on the GPU using Vulkan โจ
it accepts these options:
sizeXโ horizontal radius size. Range is[1, 32], default value is3.sizeYโ vertical radius size. Range is[1, 32], default value is3.planesโ which planes get filtered. Default value is0xf, which means all planes get processed ๐
๐ธ blend_vulkan
blends two Vulkan frames into each other, iconic behavior honestly.
The blend filter takes two input streams and spits out one stream โ the first input is the "top" layer, the second input is the "bottom" layer. By default, the output terminates when the longest input terminates.
here's the option rundown:
c0_modec1_modec2_modec3_modeall_mode
โ these set the blend mode for a specific pixel component, or for all pixel components in the case of all_mode. Default value is "normal".
the available values for component modes are:
normalmultiply
๐ฆ bwdif_vulkan
a deinterlacer using bwdif โ that's the "Bob Weaver Deinterlacing Filter" algorithm โ implemented on the GPU using Vulkan ๐ฅ
it accepts these parameters:
modeโ the interlacing mode to adopt. takes one of:0,send_frameโ output one frame for each frame.1,send_fieldโ output one frame for each field.
default value is "send_field".
parityโ the picture field parity assumed for the input interlaced video. takes one of:0,tffโ assume the top field is first.1,bffโ assume the bottom field is first.-1,autoโ enable automatic detection of field parity.
default value is "auto". If the interlacing is unknown or the decoder doesn't export that info, top field first gets assumed. no cap ๐
deintโ which frames to deinterlace. accepts one of:0,allโ deinterlace all frames.1,interlacedโ only deinterlace frames marked as interlaced.
default value is "all".
๐ chromaber_vulkan
applies an effect that emulates chromatic aberration โจ works best with RGB inputs, but still gives you a similar effect with YCbCr inputs too, so no worries.
dist_xโ horizontal displacement multiplier. Each chroma pixel's position gets multiplied by this amount, starting from the center of the image. Default is0.dist_yโ same deal but vertical: sets the vertical displacement multiplier. Default is0.
๐ color_vulkan
a video source that creates a Vulkan frame of a solid color. super useful for benchmarking, or for overlaying. main character energy for a solid rectangle honestly ๐ซถ
it accepts these parameters:
colorโ the color to use. either a name, or a hexadecimal value. default value is"black".sizeโ the size of the output frame. default value is"1920x1080".rateโ the framerate to output at. default value is60frames per second.durationโ the video duration. default value is-0.000001.sarโ the video signal aspect ratio. default value is"1/1".formatโ the pixel format of the output Vulkan frames. default value is"yuv444p".out_rangeโ set the output YCbCr sample range.
this lets you override the autodetected value and force a specific value used for the output and encoder. If you don't specify it, the range depends on the pixel format. possible values:
auto/unknownโ choose automatically.jpeg/full/pcโ set full range (0-255in case of 8-bit luma).mpeg/limited/tvโ set "MPEG" range (16-235in case of 8-bit luma).
โญ vflip_vulkan
flips an image vertically. that's it, that's the whole filter ๐
โญ hflip_vulkan
flips an image horizontally. equally unbothered, equally iconic.
โญ flip_vulkan
flips an image along both the vertical and horizontal axis. double flip, double slay ๐
โจ gblur_vulkan
applies a Gaussian blur filter on Vulkan frames ๐ฆ
the filter accepts these options:
sigmaโ horizontal sigma, the standard deviation of the Gaussian blur. Default is0.5.sigmaVโ vertical sigma. if it's negative it'll be the same assigma. Default is-1.planesโ which planes to filter. by default all planes get filtered.sizeโ the kernel size along the horizontal axis. Default is19.sizeVโ the kernel size along the vertical axis. Default is0, which means "just use the same value assize".
๐ nlmeans_vulkan
denoises frames using the Non-Local Means algorithm, implemented on the GPU using Vulkan โจ it supports more pixel formats than nlmeans or nlmeans_opencl, including alpha channel support. we love an upgrade ๐
the filter accepts these options:
sโ denoising strength for all components. Default is1.0. Must be in range[0.0, 100.0].pโ patch size for all planes. Default is7. Must be an odd number in range[0, 99].rโ research size. Default is15. Must be an odd number in range[0, 99].tโ parallelism. Default is8. Must be a number in range[1, 64]. Larger values use more VRAM but might not actually be faster โ the optimal value depends on your hardware and your input, ngl.s0s1s2s3
โ denoising strength for a specific component. Default is 1.0, equal to s. Must be in range [0.0, 100.0]. Setting 0.0 disables denoising in that component entirely.
p0p1p2p3
โ patch size for a specific component. Default is 7, equal to p. Must be an odd number in range [0, 99].
๐ overlay_vulkan
overlays one video on top of another, classic.
it takes two inputs and has one output. the first input is the "main" video, and the second input gets overlaid on top of it. heads up: this filter requires all inputs to use the same pixel format, so you might need some format conversion first ๐
the filter accepts these options:
xโ the x coordinate of the overlaid video on the main video. Default value is0.yโ the y coordinate of the overlaid video on the main video. Default value is0.
๐ง transpose_vulkan
transposes rows with columns in the input video and optionally flips it. for more in-depth examples go check the transpose video filter, which shares mostly the same options ๐
it accepts these parameters:
dirโ specify the transposition direction.
can assume these values:
cclock_flipโ rotate by 90 degrees counterclockwise and vertically flip. (default)clockโ rotate by 90 degrees clockwise.cclockโ rotate by 90 degrees counterclockwise.clock_flipโ rotate by 90 degrees clockwise and vertically flip.
passthroughโ do NOT apply the transposition if the input geometry matches the one specified by the given value. accepts these values:noneโ always apply transposition. (default)portraitโ preserve portrait geometry (whenheight >= width).landscapeโ preserve landscape geometry (whenwidth >= height).
๐ QSV VIDEO FILTERS ๐
Okay bestie, here's the rundown on the QSV filters that are available rn. โจ
To even get these filters to compile, you gotta configure FFmpeg with --enable-libmfx or --enable-libvpl. No cap, that's the price of admission. ๐๏ธ
And to actually use QSV filters, you need to set up the QSV device correctly first โ like, properly properly. For the full tea, go read <https://trac.ffmpeg.org/wiki/Hardware/QuickSync> ๐ซถ
hstack_qsv
Stack your input videos horizontally, horizontally, horizontally. ๐
This is the QSV glow-up of the hstack filter, and the cute thing about it is each input stream can have a different height โ the filter will scale each input stream down/up while keeping the original aspect. Iconic behavior honestly. ๐ฆ
It accepts the following options:
inputsโ seehstack.shortestโ seehstack.heightโ sets the height of the output. If you set it to0, this filter will set the height of the output to the height of the first input stream. Default value is0.
vstack_qsv
Stack your input videos vertically. โฌ๏ธโฌ๏ธ
This is the QSV variant of the vstack filter, each input stream may have different width, and this filter will scale down/up each input stream while keeping the original aspect. Same energy, different axis. ๐
It accepts the following options:
inputsโ seevstack.shortestโ seevstack.widthโ set the width of the output. If set to0, this filter will set the width of the output to the width of the first input stream. Default value is0.
xstack_qsv
Stack video inputs into a custom layout. Like interior design but for pixels. ๐๏ธโจ
This is the QSV variant of the xstack filter.
It accepts the following options:
inputsโ seexstack.shortestโ seexstack.layoutโ seexstack. Moreover, this one lets you supply the output size for each input stream. Yes bestie, per-input sizing, we love to see it:
xstack_qsv=inputs=4:layout=0_0_1920x1080|0_h0_1920x1080|w0_0_1920x1080|w0_h0_1920x1080
gridโ seexstack.grid_tile_sizeโ sets the output size for each input stream whengridis set. If this option is not set, this filter will set the output size by default to the size of the first input stream. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. ๐fillโ seexstack.
๐ VIDEO SOURCES ๐
Below is a description of the currently available video sources. Yes, we're going to the source of things. ๐
buffer
Buffer video frames, and make them available to the filter chain. It's literally a little holding pen for frames. ๐งบ
This source is mainly intended for a programmatic use, in particular through the interface defined in libavfilter/buffersrc.h.
It accepts the following parameters:
video_sizeโ specify the size (width and height) of the buffered video frames. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual.widthโ the input video width.heightโ the input video height.pix_fmtโ a string representing the pixel format of the buffered video frames. It may be a number corresponding to a pixel format, or a pixel format name. Either hits. ๐time_baseโ specify the timebase assumed by the timestamps of the buffered frames.frame_rateโ specify the frame rate expected for the video stream.colorspaceโ a string representing the color space of the buffered video frames. It may be a number corresponding to a color space, or a color space name.rangeโ a string representing the color range of the buffered video frames. It may be a number corresponding to a color range, or a color range name.alpha_modeโ a string representing the alpha mode of the buffered video frames. It may be a number corresponding to an alpha mode, or an alpha mode name.pixel_aspect,sarโ the sample (pixel) aspect ratio of the input video.hw_frames_ctxโ when using a hardware pixel format, this should be a reference to anAVHWFramesContextdescribing input frames.
For example:
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
will instruct the source to accept video frames with size 320x240 and with format yuv410p, assuming 1/24 as the timestamps timebase and square pixels (1:1 sample aspect ratio). And since the pixel format with name yuv410p corresponds to the number 6 (check the enum AVPixelFormat definition in libavutil/pixfmt.h), this example corresponds to:
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
Alternatively, the options can be specified as a flat string, but heads up bestie:
This syntax is deprecated. โ ๏ธ Like, it still works, but it's giving legacy.
width:height:pix_fmt:time_base.num:time_base.den:pixel_aspect.num:pixel_aspect.den
cellauto
Create a pattern generated by an elementary cellular automaton. Yes, math girlies rise up, this one's for you. ๐งโโ๏ธโจ
The initial state of the cellular automaton can be defined through the filename and pattern options. If such options are not specified, an initial state is created randomly. Chaos mode: enabled. ๐ฒ
At each new frame a new row in the video is filled with the result of the cellular automaton next generation. The behavior when the whole frame is filled is defined by the scroll option.
This source accepts the following options:
filename,fโ read the initial cellular automaton state, i.e. the starting row, from the specified file. In the file, each non-whitespace character is considered an alive cell, a newline will terminate the row, and further characters in the file will be ignored.pattern,pโ read the initial cellular automaton state, i.e. the starting row, from the specified string. Each non-whitespace character in the string is considered an alive cell, a newline will terminate the row, and further characters in the string will be ignored.rate,rโ set the video rate, that is the number of frames generated per second. Default is25.random_fill_ratio,ratioโ set the random fill ratio for the initial cellular automaton row. It is a floating point number value ranging from0to1, defaults to1/PHI. This option is ignored when a file or a pattern is specified.random_seed,seedโ set the seed for filling randomly the initial row, must be an integer included between0andUINT32_MAX. If not specified, or if explicitly set to-1, the filter will try to use a good random seed on a best effort basis. She'll try her best. ๐ซกruleโ set the cellular automaton rule, it is a number ranging from0to255. Default value is110.size,sโ set the size of the output video. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. Iffilenameorpatternis specified, the size is set by default to the width of the specified initial state row, and the height is set to width*PHI. Ifsizeis set, it must contain the width of the specified pattern string, and the specified pattern will be centered in the larger row. If afilenameor apatternstring is not specified, thesizevalue defaults to320x518(used for a randomly generated initial state).scrollโ if set to1, scroll the output upward when all the rows in the output have been already filled. If set to0, the new generated row will be written over the top row just after the bottom row is filled. Defaults to1.start_full,fullโ if set to1, completely fill the output with generated rows before outputting the first frame. This is the default behavior, for disabling set the value to0.stitchโ if set to1, stitch the left and right row edges together. This is the default behavior, for disabling set the value to0.
Examples
- Read the initial state from
pattern, and specify an output of size200x400.
cellauto=f=pattern:s=200x400
- Generate a random initial row with a width of 200 cells, with a fill ratio of
2/3:
cellauto=ratio=2/3:s=200x200
- Create a pattern generated by rule 18 starting by a single alive cell centered on an initial row with width 100:
cellauto=p=@s=100x400:full=0:rule=18
- Specify a more elaborated initial pattern:
cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
coreimagesrc
Video source generated on GPU using Apple's CoreImage API on OSX. ๐โจ
This video source is a specialized version of the coreimage video filter. Use a core image generator at the beginning of the applied filterchain to generate the content.
The coreimagesrc video source accepts the following options:
list_generatorsโ list all available generators along with all their respective options as well as possible minimum and maximum values along with the default values.
list_generators=true
size,sโ specify the size of the sourced video. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. The default value is320x240.rate,rโ specify the frame rate of the sourced video, as the number of frames generated per second. It has to be a string in the format frame_rate_num/frame_rate_den, an integer number, a floating point number or a valid video frame rate abbreviation. The default value is25.sarโ set the sample aspect ratio of the sourced video.duration,dโ set the duration of the sourced video. See the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. If not specified, or the expressed duration is negative, the video is supposed to be generated forever. โพ๏ธ
Additionally, all options of the coreimage video filter are accepted. A complete filterchain can be used for further processing of the generated input without CPU-HOST transfer. See coreimage documentation and examples for details.
Examples
- Use
CIQRCodeGeneratorto create a QR code for the FFmpeg homepage, given as complete and escaped command-line for Apple's standard bash shell:
ffmpeg -f lavfi -i coreimagesrc=s=100x100:filter=CIQRCodeGenerator@inputMessage=https\\\\\://FFmpeg.org/@inputCorrectionLevel=H -frames:v 1 QRCode.png
This example is equivalent to the QRCode example of coreimage without the need for a nullsrc video source. Slay, no extra source needed. ๐
ddagrab
Captures the Windows Desktop via Desktop Duplication API. Screen-record girlie hours. ๐ช๐
The filter exclusively returns D3D11 Hardware Frames, for on-gpu encoding or processing. So an explicit hwdownload is needed for any kind of software processing. Don't forget it or you'll be confused and sad. ๐ญ
It accepts the following options:
output_idxโ DXGI Output Index to capture. Usually corresponds to the index Windows has given the screen minus one, so it's starting at0. Defaults to output0.draw_mouseโ whether to draw the mouse cursor. Defaults totrue. Only affects hardware cursors. If a game or application renders its own cursor, it'll always be captured. ๐ฑ๏ธ (can't hide that one, sorry bestie)framerateโ the max framerate your desktop gets captured at, bestie โจ the gap between frames is never smaller than 1/framerate. Whendup_framesis true (and it is, by default) and your desktop just isn't updating fast enough, the filter goes ahead and duplicates a previous frame to keep the vibe going. Heads up though ๐ there's no background buffering happening, so if the filter isn't polled often enough, the actual inter-frame interval can end up way bigger than you'd think.
Defaults to 30 FPS.
video_sizeโ sets the size of the captured video ๐
Defaults to the full size of the screen.
Cropped from the bottom/right if it's smaller than the screen size.
offset_xโ horizontal offset of the captured video.offset_yโ vertical offset of the captured video.output_fmtโ the output format you want, queen ๐ defaults to 8 Bit BGRA.
It accepts these values:
autoโ passes all supported output formats to DDA and just returns whatever DDA decides to use. letting DDA cook ๐ฅ8bit,bgraโ 8 Bit formats always work, and DDA converts to them if necessary. no notes, iconic.10bit,x2bgr10โ filter initialization will fail if a 10 bit format is requested but unavailable ๐ญ no cap, that's a hard fail.
dup_framesโ when set totrue(the default), the filter duplicates frames whenever the desktop hasn't been updated, so it can keep an approximately constant target framerate ๐ฏ When set tofalse, the filter just waits for the desktop to update โ and in that case the inter-frame intervals may vary significantly.
Examples
Capture the primary screen and encode using nvenc:
ffmpeg -f lavfi -i ddagrab -c:v h264_nvenc -cq 18 output.mp4
You can also skip the lavfi device and directly use the filter โจ This one also demonstrates downloading the frame and encoding with libx264. Explicit output format specification is required in this case:
ffmpeg -filter_complex ddagrab=output_idx=1:framerate=60,hwdownload,format=bgra -c:v libx264 -crf 18 output.mp4
If you want to capture only a subsection of the desktop, you can do that by specifying a smaller size plus its offsets into the screen ๐ซถ
ddagrab=video_size=800x600:offset_x=100:offset_y=100
gfxcapture
Capture windows or monitors using the Windows.Graphics.Capture API ๐ชโจ
This source gives you low overhead capture of application windows or entire monitors. The filter outputs hardware frames in d3d11 format โ so use hwdownload,format= if you need system memory frames, mkay?
Which window gets captured? You can pick it via regular expressions on its title, class name or backing executable name, by explicit native handles, or by monitor index or explicit native handle. A window has to match all the expressions you provide to be selected ๐ The first matching window gets picked, in whatever order Windows happens to return them (chaotic, I know ๐).
Explicit handles (hwnd, hmonitor) override pattern or index based selection. If neither handles nor a monitor index are given, the first window matching the provided regular expressions is captured.
This source does NOT hold a stable FPS, bestie ๐ญ It returns frames at whatever rate the compositor provides them, only capped bymax_framerate. If you need a stable rate, you need to add anfpsfilter to drop/duplicate frames as needed.
If the capture source disappears mid-capture (window closed, monitor disconnected), the filter will return EOF.
This source accepts the following options:
window_titleโ ECMAScript regular expression matched against the window title. Supports a PCRE style(?i)prefix for case-insensitive matching ๐ธwindow_classโ same aswindow_title, but matched against the window class name.window_exeโ same aswindow_title, but matched against the executable file name of the window's process.monitor_idxโ zero-based index of the monitor to capture.
Can also be set to window to capture the monitor the selected window is displayed on at filter initialization time ๐ฅ๏ธ
hwndโ explicit native window handle (HWND).hmonitorโ explicit native monitor handle (HMONITOR).capture_cursorโ capture the mouse cursor. Enabled by default.capture_borderโ capture the full area of the window, including its window decorarions/border. Disabled by default.display_borderโ draw a yellow highlight border around the captured window ๐ Disabled by default.max_framerateโ maximum capture frame rate. Accepts a video rate (e.g.30,"60/1","24000/1001"). The default is60FPS. The actual rate is the rate at which the compositor renders the window/monitor, capped by this option.widthโ force the output canvas width. If zero (default) the initial captured source width is used. If a negative number is provided, the width will be rounded down to the next multiple of that number.
See resize_mode.
heightโ force the output canvas height. If zero (default) the initial captured source height is used. If a negative number is provided, the height will be rounded down to the next multiple of that number.
See resize_mode.
crop_leftโ crop this many pixels from the left side of the captured frames.crop_topโ crop this many pixels from the left side of the captured frames.crop_rightโ crop this many pixels from the left side of the captured frames.crop_bottomโ crop this many pixels from the left side of the captured frames.
okay so yes, the docs literally say "left side" for all four of these ๐ that's exactly what the page says, I'm just the messenger bestie ๐
premultipliedโ if set to1, return frames with premultiplied alpha. Default is0(straight alpha).resize_modeโ defines how the captured content is fitted into the output canvas size. Possible values:cropโ crop (or pad with black) to the canvas size. (default)scaleโ scale the source to fill the canvas, potentially altering aspect ratio ๐scale_aspectโ scale the source to fit inside the canvas while preserving aspect ratio. Remaining area is filled with black.
scale_modeโ scaling algorithm used when resizing is required. Possible values:pointโ nearest neighbour (pixelated) scaling.bilinearโ bilinear filtering. (default)bicubicโ bicubic filtering. Potentially more blurry, but fewer scaling artifacts depending on contents.
output_fmtโ desired output pixel format inside the D3D11 hardware frames. Possible values:bgra,8bitโ 8 bit BGRA output (default)x2bgr10,10bitโ 10 bit BGR outputrgbaf16,16bitโ 16bit float RGBA output
Examples
Capture a window by title (case-insensitive) at a maximum of 60 fps:
ffmpeg -filter_complex gfxcapture=window_title='(?i)My Application':max_framerate=60,hwdownload,format=bgra,format=yuv420p -c:v libx264 -crf 15 capture.mp4
Capture monitor 1 at native refresh, 10bit color depth, scale to 1920x1080 preserving aspect:
ffmpeg -filter_complex gfxcapture=monitor_idx=1:width=1920:height=1080:resize_mode=scale_aspect:output_fmt=10bit -c:v hevc_nvenc -cq 15 capture.mp4
Capture a window by executable name, draw border, force point scaling, fixed 60 fps:
ffmpeg -filter_complex gfxcapture=window_exe='^firefox.exe$':display_border=1:scale_mode=point,fps=60 -rc qvbr -qvbr_quality_level 15 -c:v h264_amf capture.mp4
gradients
Generate several gradients ๐โจ aesthetic af, honestly.
size,sโ set frame size. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. Default value is640x480.rate,rโ set frame rate, expressed as number of frames per second. Default value is25.c0,c1,c2,c3,c4,c5,c6,c7โ set 8 colors. The default behavior for colors is to pick a random one ๐ฒx0,y0,y0,y1โ set gradient line source and destination points. If negative or out of range, random ones are picked.nb_colors,nโ set number of colors to use at once. Allowed range is from2to8. Default value is2.seedโ set seed for picking gradient line points.duration,dโ set the duration of the sourced video. See the Time duration section in theffmpeg-utils(1)manual for the accepted syntax.
If not specified, or the expressed duration is negative, the video is supposed to be generated forever โพ๏ธ
speedโ set speed of gradients rotation.type,tโ set type of gradients. Available values are:linearradialcircularspiralsquare
Default type is linear.
Commands
This source supports the some above options as commands ๐
mandelbrot
Generate a Mandelbrot set fractal, and progressively zoom towards the point specified with start_x and start_y ๐ lowkey mesmerizing, ngl.
This source accepts the following options:
end_ptsโ set the terminal pts value. Default value is400.end_scaleโ set the terminal scale value. Must be a floating point value. Default value is0.3.innerโ set the inner coloring mode, that is the algorithm used to draw the Mandelbrot fractal internal region.
It shall assume one of the following values:
blackโ set black mode.convergenceโ show time until convergence.mincolโ set color based on point closest to the origin of the iterations.periodโ set period mode.
Default value is mincol.
bailoutโ set the bailout value. Default value is10.0.maxiterโ set the maximum of iterations performed by the rendering algorithm. Default value is7189.outerโ set outer coloring mode. It shall assume one of following values:iteration_countโ set iteration count mode.normalized_iteration_countโ set normalized iteration count mode.
Default value is normalized_iteration_count.
rate,rโ set frame rate, expressed as number of frames per second. Default value is25.size,sโ set frame size. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. Default value is640x480.start_scaleโ set the initial scale value. Default value is3.0.start_xโ set the initial x position. Must be a floating point value between-100and100. Default value is-0.743643887037158704752191506114774.start_yโ set the initial y position. Must be a floating point value between-100and100. Default value is-0.131825904205311970493132056385139.
mptestsrc
Okay bestie, this one serves up a whole buffet of test patterns โ the same ones the MPlayer test filter makes. The size is fixed and non-negotiable: 512x512. It's highkey the go-to source for testing encoding features, so if you're doing a vibe check on your encoder, this is your girl. โจ
It takes these options:
rate,rโ the frame rate of the sourced video, i.e. how many frames get generated per second. Gotta be a string shaped likeframe_rate_num/frame_rate_den, or a plain integer, or a floating point number, or a legit video frame rate abbreviation. Default is"25".duration,dโ how long the sourced video runs. Peep the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. If you don't set it, or the duration you express is negative, the video is assumed to be generated forever (main character energy, no end in sight ๐ญ).test,tโ the number or name of the test to run. Supported tests are:dc_lumadc_chromafreq_lumafreq_chromaamp_lumaamp_chromacbpmvring1ring2allmax_frames,mโ the max number of frames generated for each test, default value is30.
Default value is "all", which cycles through the whole list of tests. ๐
Some examples, because we love a demo:
mptestsrc=t=dc_luma
That one generates a "dc_luma" test pattern. Slay. ๐
frei0r_src
Provides a frei0r source. ๐ง
Heads up: to enable compilation of this filter you need to install the frei0r header and configure FFmpeg with --enable-frei0r. No header, no filter, that's the deal.
It takes these parameters:
sizeโ the size of the video to generate. For the syntax, check the"Video size"section in theffmpeg-utilsmanual.framerateโ the framerate of the generated video. Can be a string of the formnum/denor a frame rate abbreviation.filter_nameโ the name of the frei0r source to load. Want more info on frei0r and how to set the parameters? Read the frei0r section in the video filters documentation.filter_paramsโ a'|'-separated list of parameters to pass to the frei0r source.
For example, to generate a frei0r partik0l source with size 200x200 and frame rate 10, overlaid on the overlay filter's main input:
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
life
Generates a life pattern, bestie. ๐ฆ
This source is based on a generalization of John Conway's life game.
The sourced input represents a life grid โ every pixel is a cell that can be in one of two states: alive or dead. Every cell interacts with its eight neighbours, meaning the cells that are horizontally, vertically, or diagonally adjacent.
At each interaction the grid evolves according to whichever rule is adopted, and the rule specifies how many alive neighbor cells will make a cell stay alive or be born. The rule option is literally how you pick that rule. ๐
This source accepts these options:
filename,fโ the file to read the initial grid state from. In that file, every non-whitespace character counts as an alive cell, and a newline delimits the end of each row. If you don't set this option, the initial grid is generated randomly. ๐ฒrate,rโ the video rate, i.e. the number of frames generated per second. Default is25.random_fill_ratio,ratioโ the random fill ratio for the initial random grid. It's a floating point number from 0 to 1, defaults to1/PHI. It is ignored when a file is specified (so don't @ me when it does nothing).random_seed,seedโ the seed for filling the initial random grid, must be an integer between 0 andUINT32_MAX. If not specified, or explicitly set to-1, the filter will try to use a good random seed on a best effort basis.ruleโ the life rule. You can set a rule with a code of the kind"SNS/BNB", where NS and NB are sequences of numbers in the range 0-8. NS specifies the number of alive neighbor cells which make a live cell stay alive, and NB the number of alive neighbor cells which make a dead cell become alive (i.e. to be "born")."s"and"b"can be used in place of"S"and"B"respectively.
Alternatively, a rule can be specified by an 18-bits integer. The 9 high order bits encode the next cell state if it's alive, for each number of neighbor alive cells; the low order bits specify the rule for "borning" new cells. Higher order bits encode for a higher number of neighbor cells. For example the number 6153 = (12<<9)+9 specifies a stay alive rule of 12 and a born rule of 9, which corresponds to "S23/B03".
Default value is "S23/B3", which is the original Conway's game of life rule โ keeps a cell alive if it has 2 or 3 neighbor alive cells, and borns a new cell if there are three alive cells around a dead cell. iconic. ๐
size,sโ the size of the output video. For the syntax, check the"Video size"section in theffmpeg-utilsmanual.
If filename is specified, the size defaults to the same size as the input file. If size is set, it must contain the size specified in the input file, and the initial grid defined in that file gets centered in the larger resulting area.
If a filename is not specified, the size value defaults to "320x240" (used for a randomly generated initial grid).
stitchโ if set to 1, stitch the left and right grid edges together, and the top and bottom edges too. Defaults to1.moldโ cell mold speed. If set, a dead cell goes fromdeath_colortomold_colorwith a step ofmold.moldcan have a value from 0 to 255. ๐life_colorโ the color of living (or new born) cells.death_colorโ the color of dead cells. Ifmoldis set, this is the first color used to represent a dead cell.mold_colorโ the mold color, for definitely dead and moldy cells.
For the syntax of these 3 color options, check the "Color" section in the ffmpeg-utils manual.
Examples
- Read a grid from
pattern, and center it on a grid of size300x300pixels:
life=f=pattern:s=300x300
- Generate a random grid of size
200x200, with a fill ratio of2/3:
life=ratio=2/3:s=200x200
- Specify a custom rule for evolving a randomly generated grid:
life=rule=S14/B34
- Full example with slow death effect (mold) using
ffplay:
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
perlin
Generates Perlin noise. ๐ซ๏ธ
Perlin noise is a kind of noise with local continuity in space. It's useful for generating patterns with continuity in space and time โ think simulating smoke, fluids, or terrain. Obsessed honestly.
If more than one octave is specified through the octaves option, Perlin noise gets generated as a sum of components, each one with doubled frequency. In that case the persistence option specifies the ratio of the amplitude with respect to the previous component. More octave components let you specify more high frequency details in the generated noise (like small size variations due to boulders in a generated terrain ๐ชจ).
Options
size,sโ the size (width and height) of the buffered video frames. For the syntax, check the"Video size"section in theffmpeg-utilsmanual. Default value is"320x240".rate,rโ the frame rate expected for the video stream, expressed as a number of frames per second. Default value is25.octavesโ the total number of components making up the noise, each one with doubled frequency. Default value is1.persistenceโ the ratio used to compute the amplitude of the next octave component with respect to the previous component amplitude. Default value is1.xscale,yscaleโ define a scale factor used to multiple the x, y coordinates. Useful for an effect with a pattern stretched along the x or y axis. Default value is1.tscaleโ define a scale factor used to multiple the time coordinate. Useful to change the time variation speed. Default value is1.random_modeโ the random mode used to compute the initial pattern. Supported values are:randomโ compute and use random seed.kenโ use the predefined initial pattern defined by Ken Perlin in the original article, can be useful to compare the output with other sources.seedโ use the value specified by therandom_seedoption.
Default value is "random".
random_seed,seedโ whenrandom_modeis set torandom_seed, use this value to compute the initial pattern. Default value is0.
Examples
- Generate single component:
perlin
- Use Perlin noise with 7 components, each one with a halved contribution to total amplitude:
perlin=octaves=7:persistence=0.5
- Chain Perlin noise with the
lutyuvto generate a black&white effect:
perlin=octaves=3:tscale=0.3,lutyuv=y='if(lt(val\,128)\,255\,0)'
- Stretch noise along the y axis, and convert gray level to red-only signal:
perlin=octaves=7:tscale=0.4:yscale=0.3,lutrgb=r=val:b=0:g=0
qrencodesrc
Generates a QR code using the libqrencode library (see <https://fukuchi.org/works/qrencode/>). ๐
To enable the compilation of this source, you need to configure FFmpeg with --enable-libqrencode. No configure flag, no QR codes, sorry bestie.
The QR code gets generated from the provided text or text pattern. The corresponding QR code is scaled and put in the video output according to the specified output size options.
In case no text is specified, the QR code is not generated โ instead you get an empty colored output back. ๐
This source accepts these options:
qrcode_width,qโ specify an expression for the width of the rendered QR code, with padding.padded_qrcode_width,Qโ specify an expression for the width of the rendered QR code, without padding.
The qrcode_width expression can reference the value set by the padded_qrcode_width expression, and vice versa. By default padded_qrcode_width is set to qrcode_width, meaning there is no padding.
These expressions are evaluated only once, when initializing the source. See the qrencode Expressions section for details. โจ
okay so real talk bestie: some of the constants are missing for the source (for example x or t or ยธn), because they only make sense when you evaluate the expression for each frame rather than at initialization time. no cap. ๐
rate,rโ set the frame rate of the sourced video, as the number of frames generated per second. It has to be a string in the formatframe_rate_num/frame_rate_den, an integer number, a floating point number or a valid video frame rate abbreviation. Default is"25". โจcase_sensitive,csโ tell libqrencode to use case sensitive encoding. Itโs enabled by default. You can disable it to reduce the QR encoding size.level,lโ set the QR encoding error correction level. Higher correction level means bigger encoding size, but the code is more robust to corruption. The lower level isL. It acceptsL,M,Q,H. ๐expansionโ choose how the input text is expanded. Can benoneornormal(default). See the qrencode Text expansion section for details.text,textfileโ define the text to render. If neither is specified, no QR is encoded (just an empty colored frame). If expansion is enabled, the text is treated as a text template using the qrencode expansion mechanism. See the qrencode Text expansion section for details. ๐ซถbackground_color,bcandforeground_color,fcโ set the QR code and background color. The default forforeground_colorisblack, and the default forbackground_coloriswhite. For the syntax of the color options, check theColorsection in the ffmpeg-utils manual. ๐
โจ Examples โจ
- Generate a QR code encoding the specified text with the default size:
qrencodesrc=text=www.ffmpeg.org
- Same as below, but select blue on pink colors:
qrencodesrc=text=www.ffmpeg.org:bc=pink:fc=blue
- Generate a QR code with width of 200 pixels and padding, making the padded width
4/3of the QR code width:
qrencodesrc=text=www.ffmpeg.org:q=200:Q=4/3*q
- Generate a QR code with padded width of 200 pixels and padding, making the QR code width
3/4of the padded width:
qrencodesrc=text=www.ffmpeg.org:Q=200:q=3/4*Q
- Generate a QR code encoding the frame number:
qrencodesrc=text=%{n}
- Generate a QR code encoding the GMT timestamp:
qrencodesrc=text=%{gmtime}
- Generate a QR code encoding the timestamp expressed as a float:
qrencodesrc=text=%{pts}
โจ allrgb, allyuv, color, colorchart, colorspectrum, haldclutsrc, nullsrc, pal75bars, pal100bars, rgbtestsrc, smptebars, smptehdbars, testsrc, testsrc2, yuvtestsrc โจ
allrgbโ returns frames of size4096x4096of all rgb colors. ๐allyuvโ returns frames of size4096x4096of all yuv colors.colorโ provides a uniformly colored input.colorchartโ provides a colors checker chart. ๐จcolorspectrumโ provides a color spectrum input.haldclutsrcโ provides an identity Hald CLUT. See also thehaldclutfilter.nullsrcโ returns unprocessed video frames. Itโs mainly useful in analysis / debugging tools, or as the source for filters which ignore the input data. ๐pal75barsโ generates a color bars pattern based on EBU PAL recommendations with 75% color levels.pal100barsโ generates a color bars pattern based on EBU PAL recommendations with 100% color levels.rgbtestsrcโ generates an RGB test pattern useful for detecting RGB vs BGR issues. You should see a red, green and blue stripe from top to bottom. ๐smptebarsโ generates a color bars pattern based on the SMPTE Engineering Guideline EG 1-1990.smptehdbarsโ generates a color bars pattern based on the SMPTE RP 219-2002.testsrcโ generates a test video pattern showing a color pattern, a scrolling gradient and a timestamp. This is mainly intended for testing purposes. โจtestsrc2โ similar totestsrc, but supports more pixel formats instead of justrgb24. This lets you use it as an input for other tests without requiring a format conversion.yuvtestsrcโ generates a YUV test pattern. You should see a y, cb and cr stripe from top to bottom.
The sources accept the following parameters:
levelโ set the level of the Hald CLUT, only available in thehaldclutsrcsource. A level ofNgenerates a picture ofN*N*NbyN*N*Npixels to be used as identity matrix for 3D lookup tables. Each component is coded on a1/(N*N)scale.color,cโ set the color of the source, only available in thecolorsource. For the syntax of this option, check theColorsection in the ffmpeg-utils manual. ๐size,sโ set the size of the sourced video. For the syntax of this option, check theVideo sizesection in the ffmpeg-utils manual. Default is320x240. This option is not available with theallrgb,allyuv, andhaldclutsrcfilters.rate,rโ set the frame rate of the sourced video, as the number of frames generated per second. It has to be a string in the formatframe_rate_num/frame_rate_den, an integer number, a floating point number or a valid video frame rate abbreviation. Default is"25". ๐ธduration,dโ set the duration of the sourced video. See the Time duration section in theffmpeg-utils(1)manual for the accepted syntax. If not specified, or if the expressed duration is negative, the video is supposed to be generated forever. Since the frame rate is used as time base, all frames including the last one will have their full duration. If the specified duration is not a multiple of the frame duration, it will be rounded up. ๐ฐ๏ธsarโ set the sample aspect ratio of the sourced video.alphaโ set the alpha (opacity) of the background, only available in thetestsrc2source. The value must be between0(fully transparent) and255(fully opaque, the default).decimals,nโ set the number of decimals to show in the timestamp, only available in thetestsrcsource. The displayed timestamp value corresponds to the original timestamp value multiplied by the power of 10 of the specified value. Default is0.typeโ set the type of the color spectrum, only available in thecolorspectrumsource. Can be one ofblack,white,all.patch_sizeโ set the patch size of a single color patch, only available in thecolorchartsource. Default is64x64.presetโ set the colorchecker colors preset, only available in thecolorchartsource. Available values arereference,skintones. Default isreference. ๐
โจ Examples โจ
- Generate a video with a duration of
5.3seconds, with size176x144and a frame rate of 10 frames per second:
testsrc=duration=5.3:size=qcif:rate=10
- The following graph description will generate a red source with an opacity of
0.2, with sizeqcifand a frame rate of 10 frames per second:
color=c=red@0.2:s=qcif:r=10
- If the input content is to be ignored,
nullsrccan be used. The following command generates noise in the luma plane by employing thegeqfilter:
nullsrc=s=256x256, geq=random(1)*255:128:128
โจ Commands โจ
The color source supports the following commands:
c,colorโ set the color of the created image. Accepts the same syntax as the corresponding color option.
โจ openclsrc โจ
Generate video using an OpenCL program. ๐ง
sourceโ OpenCL program source file.kernelโ kernel name in program.size,sโ size of frames to generate. This must be set.formatโ pixel format to use for the generated frames. This must be set.rate,rโ number of frames generated every second. Default is'25'.
For details of how the program loading works, see the program_opencl filter.
Example programs:
- Generate a colour ramp by setting pixel values from the position of the pixel in the output image. (Note that this will work with all pixel formats, but the generated output will not be the same.)
__kernel void ramp(__write_only image2d_t dst,
unsigned int index)
{
int2 loc = (int2)(get_global_id(0), get_global_id(1));
float4 val;
val.xy = val.zw = convert_float2(loc) / convert_float2(get_image_dim(dst));
write_imagef(dst, loc, val);
}
- Generate a Sierpinski carpet pattern, panning by a single pixel each frame.
__kernel void sierpinski_carpet(__write_only image2d_t dst,
unsigned int index)
{
int2 loc = (int2)(get_global_id(0), get_global_id(1));
float4 value = 0.0f;
int x = loc.x + index;
int y = loc.y + index;
while (x > 0 || y > 0) {
if (x % 3 == 1 && y % 3 == 1) {
value = 1.0f;
break;
}
x /= 3;
y /= 3;
}
write_imagef(dst, loc, value);
}
โจ sierpinski โจ
Generate a Sierpinski carpet/triangle fractal, and randomly pan around. ๐
This source accepts the following options:
size,sโ set frame size. For the syntax of this option, check theVideo sizesection in the ffmpeg-utils manual. Default is640x480.rate,rโ set frame rate, expressed as number of frames per second. Default is"25".seedโ set seed which is used for random panning.jumpโ set max jump for single pan destination. Allowed range is from1to10000.typeโ set fractal type, can be defaultcarpetortriangle. ๐ฅ
โจ zoneplate โจ
Generate a zoneplate test video pattern. โญ
This source accepts the following options:
size,sโ set frame size. For the syntax of this option, check theVideo sizesection in the ffmpeg-utils manual. Default is320x240.rate,rโ sets the frame rate, as a number of frames per second. default is25๐ซduration,dโ sets how long the sourced video lasts. the syntax is the Time duration section in theffmpeg-utils(1)manual, go check it ๐ซถ
if you don't specify it, or the duration you give is negative, the video is just gonna generate forever. infinite content era ๐
sarโ sets the sample aspect ratio of the sourced video โจprecisionโ sets precision in bits for the look-up table used for the sine calculations. default is10, and the allowed range is4to16๐xoโ sets the horizontal axis offset for the output signal. default is0yoโ sets the vertical axis offset for the output signal. default is0toโ sets the time axis offset for the output signal. default is0k0โ sets the 0-order constant added to the signal phase. default is0kxโ sets the 1-order phase factor multiplier for the horizontal axis. default is0kyโ sets the 1-order phase factor multiplier for the vertical axis. default is0ktโ sets the 1-order phase factor multiplier for the time axis. default is0kxt,kyt,kxyโ set the phase factor multipliers for combinations of spatial and temporal axes. default is0๐ธkx2โ sets the 2-order phase factor multiplier for the horizontal axis. default is0ky2โ sets the 2-order phase factor multiplier for the vertical axis. default is0kt2โ sets the 2-order phase factor multiplier for the time axis. default is0kuโ sets the constant added to the final phase to produce the chroma-blue component of the signal. default is0๐kvโ sets the constant added to the final phase to produce the chroma-red component of the signal. default is0
๐ฎ Commands
this source supports some of the options above as commands, iykyk ๐
๐ Examples
- generate a horizontal color sine sweep:
zoneplate=ku=512:kv=0:kt2=0:kx2=256:s=wvga:xo=-426:kt=11
- generate a vertical color sine sweep:
zoneplate=ku=512:kv=0:kt2=0:ky2=156:s=wvga:yo=-240:kt=11
- generate a circular zone-plate:
zoneplate=ku=512:kv=100:kt2=0:ky2=256:kx2=556:s=wvga:yo=0:kt=11
๐ฌ VIDEO SINKS ๐ฌ
okay bestie here's the rundown of the video sinks that are currently available. these are the endpoints โ where the pixels go to rest ๐ฆ
buffersink
buffers video frames and makes them available to the end of the filter graph. literally the finish line ๐
this sink is mainly intended for programmatic use โ especially through the interface defined in libavfilter/buffersink.h or the options system.
it accepts a pointer to an AVBufferSinkContext structure, which defines the incoming buffers' formats, and that pointer gets passed as the opaque parameter to avfilter_init_filter for initialization. yes that's very specific, yes you need all of it ๐
nullsink
a null video sink: it does absolutely nothing with the input video. zero notes. it just sits there ๐
it's mainly useful as a template, and for use in analysis / debugging tools. king of doing nothing but doing it flawlessly ๐
๐ MULTIMEDIA FILTERS ๐
and now the multimedia filters that are currently available โ these ones ate and left no crumbs โจ
a3dscope
converts the input audio into 3d scope video output. it's giving main character visualization ๐
the filter accepts the following options:
rate,rโ sets the frame rate, as a number of frames per second. default is25size,sโ specify the video size for the output. for the syntax of this option, check the Video size section in theffmpeg-utilsmanual. default ishd720๐ผ๏ธfovโ sets the camera field of view. default is 90 degrees, and the allowed range is from40to150๐rollโ sets the camera rollpitchโ sets the camera pitchyawโ sets the camera yawxzoomโ sets the camera zoom on the X-axisyzoomโ sets the camera zoom on the Y-axiszzoomโ sets the camera zoom on the Z-axisxposโ sets the camera position on the X-axisyposโ sets the camera position on the Y-axiszposโ sets the camera position on the Z-axislengthโ sets the length of the displayed audio waves, in number of frames ๐ซ
๐ฎ Commands
the filter supports some of the options above as commands ๐
abitscope
converts the input audio into a video output, displaying the audio bit scope. it's literally the audio version of a glow-up reveal ๐ญ
the filter accepts the following options:
rate,rโ sets the frame rate, as a number of frames per second. default is25size,sโ specify the video size for the output. for the syntax of this option, check the Video size section in theffmpeg-utilsmanual. default is1024x256๐colorsโ specify a list of colors, separated by a space or by|, that'll be used to draw the channels. any unrecognized or missing colors get replaced by white. no cap ๐mode,mโ sets the output mode. can bebarsortrace. default isbars
adrawgraph
draws a graph using the input audio metadata. the audio is the moment, the graph is the aesthetic ๐
see drawgraph for the details ๐ซถ
agraphmonitor
see graphmonitor โ that's the whole vibe check, go read that one ๐
ahistogram
converts the input audio into a video output, displaying the volume histogram. it's giving data visualization slay ๐
the filter accepts the following options:
dmodeโ specify how the histogram is calculated. it accepts the following values:singleโ use a single histogram for all channelsseparateโ use a separate histogram for each channel
default is single โจ
rate,rโ sets the frame rate, as a number of frames per second. default is25size,sโ specify the video size for the output. for the syntax of this option, check the Video size section in theffmpeg-utilsmanual. default ishd720scaleโ sets the display scale. it accepts the following values:logโ logarithmicsqrtโ square rootcbrtโ cubic rootlinโ linearrlogโ reverse logarithmic
default is log ๐ธ
ascaleโ sets the amplitude scale. it accepts the following values:logโ logarithmiclinโ linear
default is log
acountโ sets how many frames to accumulate in the histogram. default is1. set it to-1and it accumulates all the frames. hoarder behavior, we respect it ๐rheightโ sets the histogram ratio of window heightslideโ sets the sonogram sliding. it accepts the following values:replaceโ replace old rows with new onesscrollโ scroll from top to bottom
default is replace ๐ฆ
hmodeโ sets the histogram mode. it accepts the following values:absโ use absolute values of samplessignโ use untouched values of samples
default is abs
aphasemeter
measures the phase of the input audio, which gets exported as metadata lavfi.aphasemeter.phase, representing the mean phase of the current audio frame. a video output can also be produced, and it's enabled by default. the audio is passed through as the first output ๐
the audio will be rematrixed to stereo if it has a different channel layout. the phase value is in range [-1, 1], where -1 means the left and right channels are completely out of phase, and 1 means the channels are in phase. it's giving relationship status ngl ๐๐
the filter accepts the following options, all related to its video output:
rate,rโ sets the output frame rate. default value is25size,sโ sets the video size for the output. for the syntax of this option, check the Video size section in theffmpeg-utilsmanual. default value is800x400๐rc,gc,bcโ specify the red, green and blue contrast. default values are2,7and1. the allowed range is[0, 255]mpcโ sets the color that'll be used for drawing the median phase. if the color isnone, which is the default, no median phase value gets drawn ๐videoโ enables the video output. default is enabled
๐ phasing detection ๐
the filter also detects out of phase and mono sequences in stereo streams. it logs the sequence start, end and duration when it lasts longer than โ or as long as โ the minimum you set. it's literally a detective, obsessed ๐ต๏ธโโ๏ธ
the filter accepts the following options for this detection:
phasingโ enables mono and out of phase detection. default is disabledtolerance,tโ sets the phase tolerance for mono detection, in amplitude ratio. default is0. the allowed range is[0, 1]angle,aโ sets the angle threshold for out of phase detection, in degrees. default is170. the allowed range is[90, 180]๐duration,dโ sets the mono or out of phase duration until notification, expressed in seconds. default is2
โจ Examples โจ
- a complete example with
ffmpegto detect 1 second of mono with0.001phase tolerance:
ffmpeg -i stereo.wav -af aphasemeter=video=0:phasing=1:duration=1:tolerance=0.001 -f null -
avectorscope
converts the input audio into a video output, representing the audio vector scope. this one's a whole aesthetic ๐
the filter is used to measure the difference between the channels of a stereo audio stream. a monaural signal โ meaning identical left and right signals โ results in a straight vertical line. any stereo separation shows up as a deviation from that line, creating a Lissajous figure. and if the straight line (or a deviation from it) shows up horizontal, that means the left and right channels are out of phase. literal visual proof, no cap ๐ญ
the filter accepts the following options:
mode,mโ sets the vectorscope mode. available values are:lissajousโ Lissajous rotated by 45 degreeslissajous_xyโ same as above but not rotatedpolarโ a shape resembling half of a circle
default value is lissajous ๐ซ
size,sโ sets the video size for the output. for the syntax of this option, check the Video size section in theffmpeg-utilsmanual. default value is400x400๐rate,rโ sets the output frame rate. default value is25rc,gc,bc,acโ specify the red, green, blue and alpha contrast. default values are40,160,80and255. the allowed range is[0, 255]rf,gf,bf,afโ specify the red, green, blue and alpha fade. default values are15,10,5and5. the allowed range is[0, 255]๐ธzoomโ sets the zoom factor. default value is1, and the allowed range is[0, 10]. values lower than1will auto adjust the zoom factor to the maximal possible value. it fixes itself, self-care icon ๐drawโ sets the vectorscope drawing mode. available values are:dotโ draw a dot for each samplelineโ draw a line between the previous and current sampleaalineโ draw an anti-aliased line between the previous and current sample
default value is dot โจ
scaleโ specify the amplitude scale of the audio samples. available values are:linโ linearsqrtโ square rootcbrtโ cubic rootlogโ logarithmic
swapโ swaps the left channel axis with the right channel axis ๐mirrorโ mirrors the axis. available values are:noneโ no mirror
okay so the mirror options are short and iconic:
xโ mirror only the x axis.yโ mirror only the y axis.xyโ mirror both axis.
๐ฌ Examples
Hereโs the complete example using ffplay โ copy it exactly, bestie:
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
[a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
๐น๏ธ Commands
This filter supports the all above options as commands except options size and rate.
๐ง bench, abench
Benchmark part of a filtergraph. Itโs literally giving stopwatch energy for your filtergraphโs little runway walk. ๐
The filter accepts the following options:
actionโ start or stop a timer.
Available values are:
startโ get the current time, set it as frame metadata (using the keylavfi.bench.start_time), and forward the frame to the next filter.stopโ get the current time and fetch thelavfi.bench.start_timemetadata from the input frame metadata to get the time difference. Time difference, average, maximum and minimum time (respectivelyt,avg,maxandmin) are then printed. The timestamps are expressed in seconds.
๐ธ Examples
- Benchmark
selectivecolorfilter:
bench=start,selectivecolor=reds=-.2 .12 -.49,bench=stop
๐งต concat
Concatenate audio and video streams, joining them together one after the other. Itโs the โstitch these clips togetherโ filter, and yes, it ate. โจ
The filter works on segments of synchronized video and audio streams. All segments must have the same number of streams of each type, and that will also be the number of streams at output.
The filter accepts the following options:
nโ set the number of segments. Default is2.vโ set the number of output video streams, that is also the number of video streams in each segment. Default is1.aโ set the number of output audio streams, that is also the number of audio streams in each segment. Default is0.unsafeโ activate unsafe mode: do not fail if segments have a different format.
The filter has v+a outputs: first v video outputs, then a audio outputs.
There are n ร (v+a) inputs: first the inputs for the first segment, in the same order as the outputs, then the inputs for the second segment, etc.
Related streams do not always have exactly the same duration, for various reasons including codec frame size or sloppy authoring. For that reason, related synchronized streams (e.g. a video and its audio track) should be concatenated at once. The concat filter will use the duration of the longest stream in each segment (except the last one), and if necessary pad shorter audio streams with silence.
๐จ For this filter to work correctly, all segments must start at timestamp 0.
All corresponding streams must have the same parameters in all segments; the filtering system will automatically select a common pixel format for video streams, and a common sample format, sample rate and channel layout for audio streams, but other settings, such as resolution, must be converted explicitly by the user.
Different frame rates are acceptable but will result in variable frame rate at output; be sure to configure the output file to handle it.
๐ฌ Examples
- Concatenate an opening, an episode and an ending, all in bilingual version (video in stream 0, audio in streams 1 and 2):
ffmpeg -i opening.mkv -i episode.mkv -i ending.mkv -filter_complex \
'[0:0] [0:1] [0:2] [1:0] [1:1] [1:2] [2:0] [2:1] [2:2]
concat=n=3:v=1:a=2 [v] [a1] [a2]' \
-map '[v]' -map '[a1]' -map '[a2]' output.mkv
- Concatenate two parts, handling audio and video separately, using the
(a)moviesources, and adjusting the resolution:
movie=part1.mp4, scale=512:288 [v1] ; amovie=part1.mp4 [a1] ;
movie=part2.mp4, scale=512:288 [v2] ; amovie=part2.mp4 [a2] ;
[v1] [v2] concat [outv] ; [a1] [a2] concat=v=0:a=1 [outa]
๐จ Note that a desync will happen at the stitch if the audio and video streams do not have exactly the same duration in the first file.
๐น๏ธ Commands
This filter supports the following commands:
nextโ close the current segment and step to the next one.
๐ง ebur128
EBU R128 scanner filter. This filter takes an audio stream and analyzes its loudness level. By default, it logs a message at a frequency of 10Hz with the Momentary loudness (identified by M), Short-term loudness (S), Integrated loudness (I) and Loudness Range (LRA). Loudness girlie is doing a full vibe check on your audio. ๐โจ
The filter can only analyze streams which have sample format is double-precision floating point. The input stream will be converted to this specification, if needed. Users may need to insert aformat and/or aresample filters after this filter to obtain the original parameters.
The filter also has a video output (see the video option) with a real time graph to observe the loudness evolution. The graphic contains the logged message mentioned above, so it is not printed anymore when this option is set, unless the verbose logging is set. The main graphing area contains the short-term loudness (3 seconds of analysis), and the gauge on the right is for the momentary loudness (400 milliseconds), but can optionally be configured to instead display short-term loudness (see gauge).
The green area marks a +/- 1LU target range around the target loudness (-23LUFS by default, unless modified through target).
More info about the Loudness Recommendation EBU R128 is at http://tech.ebu.ch/loudness.
The filter accepts the following options:
videoโ activate the video output. The audio stream is passed unchanged whether this option is set or no. The video stream will be the first output stream if activated. Default is0.sizeโ set the video size. This option is for video only. For the syntax of this option, check the โVideo sizeโ section in theffmpeg-utilsmanual. Default and minimum resolution is640x480.meterโ set the EBU scale meter. Default is9. Common values are9and18, respectively for EBU scale meter +9 and EBU scale meter +18. Any other integer value between this range is allowed.metadataโ set metadata injection. If set to1, the audio input will be segmented into100msoutput frames, each of them containing various loudness information in metadata. All the metadata keys are prefixed withlavfi.r128..
Default is 0.
framelogโ force the frame logging level.
Available values are:
quietโ logging disabled.infoโ information logging level.verboseโ verbose logging level.
By default, the logging level is set to info. If the video or the metadata options are set, it switches to verbose.
peakโ set peak mode(s).
Available modes can be cumulated (the option is a flag type). Possible values are:
noneโ disable any peak mode (default).sampleโ enable sample-peak mode. Simple peak mode looking for the higher sample value. It logs a message for sample-peak (identified bySPK).trueโ enable true-peak mode. If enabled, the peak lookup is done on an over-sampled version of the input stream for better peak accuracy. It logs a message for true-peak (identified byTPK) and true-peak per frame (identified byFTPK). This mode requires a build withlibswresample.
dualmonoโ treat mono input files as โdual monoโ. If a mono file is intended for playback on a stereo system, its EBU R128 measurement will be perceptually incorrect. If set totrue, this option will compensate for this effect. Multi-channel input files are not affected by this option.panlawโ set a specific pan law to be used for the measurement of dual mono files. This parameter is optional, and has a default value of-3.01dB.targetโ set a specific target level (in LUFS) used as relative zero in the visualization. This parameter is optional and has a default value of-23LUFSas specified by EBU R128. However, material published online may prefer a level of-16LUFS(e.g. for use with podcasts or video platforms).gaugeโ set the value displayed by the gauge. Valid values aremomentaryandshortterm. By default the momentary value will be used, but in certain scenarios it may be more useful to observe the short term value instead (e.g. live mixing).scaleโ sets the display scale for the loudness. Valid parameters areabsolute(in LUFS) orrelative(LU) relative to the target. This only affects the video output, not the summary or continuous log output.integratedโ read-only exported value for measured integrated loudness, in LUFS.rangeโ read-only exported value for measured loudness range, in LU.lra_lowโ read-only exported value for measured LRA low, in LUFS.lra_highโ read-only exported value for measured LRA high, in LUFS.sample_peakโ read-only exported value for measured sample peak, in dBFS.true_peakโ read-only exported value for measured true peak, in dBFS.
๐ฌ Examples
- Real-time graph using
ffplay, with a EBU scale meter +18:
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
- Run an analysis with
ffmpeg:
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
๐ฆ interleave, ainterleave
Temporally interleave frames from several inputs. Itโs giving โeveryone gets a turnโ energy, and honestly? Obsessed. ๐
interleave works with video inputs, ainterleave with audio.
These filters read frames from several inputs and send the oldest queued frame to the output.
Input streams must have well defined, monotonically increasing frame timestamp values.
In order to submit one frame to output, these filters need to enqueue at least one frame for each input, so they cannot work in case one input is not yet terminated and will not receive incoming frames.
For example consider the case when one input is a select filter which always drops input frames. The interleave filter will keep reading from that input, but it will never be able to send new frames to output until the input sends an end-of-stream signal.
Also, depending on inputs synchronization, the filters will drop frames in case one input receives more frames than the other ones, and the queue is already filled.
These filters accept the following options:
nb_inputs,nโ set the number of different inputs, it is2by default.durationโ how to determine the end-of-stream.longestโ the duration of the longest input. (default)shortestโ the duration of the shortest input.
firstโ how long the first input runs for.
โจ Examples โจ
- Interleave frames from different streams using
ffmpegโ bestie, this is the whole vibe:
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
- Add a flickering blur effect (yes it's chaotic, yes it eats):
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
๐
latency, alatency
Measure how long filtering is taking. Basically a stopwatch for your filtergraph ๐ซถ
It reports the previous filter's filtering latency โ that's a delay measured in number of audio samples for audio filters, or number of video frames for video filters.
When the input stream ends, the filter reports the min and max measured latency for the previous running filter in the filtergraph. Receipts, periodt.
๐ metadata, ametadata
Manipulate frame metadata. Little key-value gremlins living inside your frames ๐
This filter accepts the following options:
modeโ sets the mode of operation of the filter.
It can be one of the following:
selectโ if bothvalueandkeyare set, it selects frames that have such metadata. If onlykeyis set, it selects every frame that has such key in metadata.addโ add new metadatakeyandvalue. If the key is already available, do nothing.modifyโ modify the value of an already present key.deleteโ ifvalueis set, delete only keys that have such value. Otherwise, delete the key. Ifkeyis not set, delete all metadata values in the frame. Gone, deleted, blocked ๐printโ print the key and its value if metadata was found. Ifkeyis not set, print all metadata values available in the frame.
keyโ set the key used with all modes. Mandatory for all modes exceptprintanddelete.valueโ set the metadata value that will be used. This option is mandatory formodifyandaddmode.functionโ which function to use when comparing metadata value andvalue.
Can be one of the following:
same_strโ values are interpreted as strings, returns true if the metadata value is the same asvalue.starts_withโ values are interpreted as strings, returns true if the metadata value starts with thevalueoption string.lessโ values are interpreted as floats, returns true if the metadata value is less thanvalue.equalโ values are interpreted as floats, returns true ifvalueis equal to the metadata value.greaterโ values are interpreted as floats, returns true if the metadata value is greater thanvalue.exprโ values are interpreted as floats, returns true if the expression from optionexprevaluates to true.ends_withโ values are interpreted as strings, returns true if the metadata value ends with thevalueoption string.
exprโ set the expression used whenfunctionis set toexpr. The expression is evaluated through the eval API and can contain the following constants:VALUE1,FRAMEVALโ float representation ofvaluefrom the metadata key.VALUE2,USERVALโ float representation ofvalueas supplied by the user in thevalueoption.
fileโ if specified inprintmode, output is written to the named file. Instead of a plain filename, any writable url can be specified. The filename-is a shorthand for standard output. If thefileoption is not set, output is written to the log with theAV_LOG_INFOloglevel.directโ reduces buffering in print mode when output is written to a URL set usingfile.
โจ Examples โจ
- Print all metadata values for frames with key
lavfi.signalstats.YDIFwith values between 0 and 1:
signalstats,metadata=print:key=lavfi.signalstats.YDIF:value=0:function=expr:expr='between(VALUE1,0,1)'
- Print
silencedetectoutput to the filemetadata.txt:
silencedetect,ametadata=mode=print:file=metadata.txt
- Direct all metadata to a pipe with file descriptor 4:
metadata=mode=print:file='pipe\:4'
๐ธ perms, aperms
Set read/write permissions for the output frames. Lowkey playing god with your buffers ๐ญ
These filters are mainly aimed at developers to test the direct path in the following filter in the filtergraph.
The filters accept the following options:
modeโ select the permissions mode.
It accepts the following values:
noneโ do nothing. This is the default.roโ set all the output frames read-only.rwโ set all the output frames directly writable.toggleโ make the frame read-only if writable, and writable if read-only.randomโ set each output frame read-only or writable randomly.
seedโ set the seed for therandommode; must be an integer included between0andUINT32_MAX. If not specified, or if explicitly set to-1, the filter will try to use a good random seed on a best effort basis.
Note: in case of an auto-inserted filter between the permission filter and the following one, the permission might not be received as expected in that following filter. Inserting aformatoraformatfilter before theperms/apermsfilter can avoid this problem. Fix it bestie ๐ซถ
๐ฆ realtime, arealtime
Slow down filtering to match real time approximately. It's giving "chill, we have time" energy โจ
These filters will pause the filtering for a variable amount of time to match the output rate with the input timestamps. They are similar to the re option to ffmpeg.
They accept the following options:
limitโ time limit for the pauses. Any pause longer than that will be considered a timestamp discontinuity and reset the timer. Default is2seconds.speedโ speed factor for processing. The value must be a float larger than zero. Values larger than1.0will result in faster than realtime processing, smaller will slow processing down. The limit is automatically adapted accordingly. Default is1.0.
A processing speed faster than what is possible without these filters cannot be achieved. No cap, but also, cap.
โจ Commands โจ
Both filters support all the above options as commands.
๐ segment, asegment
Split a single input stream into multiple streams. The opposite of the concat filters, fr fr.
segment works on video frames, asegment on audio samples.
This filter accepts the following options:
timestampsโ timestamps of output segments separated by|. The first segment will run from the beginning of the input stream. The last segment will run until the end of the input stream.frames,samplesโ exact frame/sample count to split the segments.
In all cases, prefixing each segment with + will make it relative to the previous segment.
โจ Examples โจ
- Split the input audio stream into three output audio streams โ starting at the start of the input audio stream and storing that in the 1st output audio stream, then following at the 60th second and storing that in the 2nd output audio stream, and last after the 150th second of the input audio stream stored in the 3rd output audio stream:
asegment=timestamps="60|150"
๐ select, aselect
Select frames to pass in the output. The bouncer of your filtergraph ๐
This filter accepts the following options:
expr,eโ set the expression, which is evaluated for each input frame.
If the expression is evaluated to zero, the frame is discarded.
If the evaluation result is negative or NaN, the frame is sent to the first output; otherwise it is sent to the output with index ceil(val)-1, assuming that the input index starts from 0.
For example a value of 1.2 corresponds to the output with index ceil(1.2)-1 = 2-1 = 1, that is the second output.
outputs,nโ set the number of outputs. The output to which to send the selected frame is based on the result of the evaluation. Default value is1.
The expression can contain the following constants:
nโ the (sequential) number of the filtered frame, starting from0.selected_nโ the (sequential) number of the selected frame, starting from0.prev_selected_nโ the sequential number of the last selected frame. It'sNANif undefined.TBโ the timebase of the input timestamps.ptsโ the PTS (Presentation TimeStamp) of the filtered frame, expressed inTBunits. It'sNANif undefined.tโ the PTS of the filtered frame, expressed in seconds. It'sNANif undefined.prev_ptsโ the PTS of the previously filtered frame. It'sNANif undefined.prev_selected_ptsโ the PTS of the last previously filtered frame. It'sNANif undefined.prev_selected_tโ the PTS of the last previously selected frame, expressed in seconds. It'sNANif undefined.start_ptsโ the first PTS in the stream which is notNAN. It remainsNANif not found.start_tโ the first PTS, in seconds, in the stream which is notNAN. It remainsNANif not found.pict_type(video only) โ the type of the filtered frame. It can assume one of the following values:IPBSSISPBI
interlace_type(video only) โ the frame interlace type. It can assume one of the following values:PROGRESSIVEโ the frame is progressive (not interlaced).TOPFIRSTโ the frame is top-field-first.BOTTOMFIRSTโ the frame is bottom-field-first.
consumed_sample_n(audio only) โ the number of selected samples before the current frame.samples_n(audio only) โ the number of samples in the current frame.sample_rate(audio only) โ the input sample rate.keyโ this is1if the filtered frame is a key-frame,0otherwise.posโ the position in the file of the filtered frame,-1if the information is not available (e.g. for synthetic video); deprecated, do not use ๐ฉscene(video only) โ value between0and1to indicate a new scene; a low value reflects a low probability for the current frame to introduce a new scene, while a higher value means the current frame is more likely to be one (see the example below).concatdec_selectโ the concat demuxer can select only part of a concat input file by setting an inpoint and an outpoint, but the output packets may not be entirely contained in the selected interval. By using this variable, it is possible to skip frames generated by the concat demuxer which are not exactly contained in the selected interval.
This works by comparing the frame pts against the lavf.concat.start_time and the lavf.concat.duration packet metadata values which are also present in the decoded frames.
concatdec_select is -1 when the frame pts is at least start_time AND either the duration metadata is missing or the frame pts is less than start_time + duration. It's 0 otherwise, and NaN if the start_time metadata is missing. ๐ซถ
Which honestly just means: a frame gets selected if its pts lands inside the interval the concat demuxer set up. That's it, that's the whole vibe check.
iw(video only) โ the width of the input video frame, bestie. ๐ih(video only) โ the height of the input video frame. ๐view(video only) โ the View ID, for multi-view video. ๐
The default value of the select expression is literally "1" โ so with no expression at all you're grabbing everything. ๐
Examples
- Select all the frames in the input:
select
The example above is exactly the same as:
select=1
- Skip all frames (bold move, but okay):
select=0
- Select only I-frames:
select='eq(pict_type\,I)'
- Select one frame every 100:
select='not(mod(n\,100))'
- Select only the frames inside the 10-20 time interval:
select=between(t\,10\,20)
- Select only the I-frames inside the 10-20 time interval:
select=between(t\,10\,20)*eq(pict_type\,I)
- Select frames with a minimum distance of 10 seconds between them:
select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
- Use
aselectto grab only audio frames with asamples_ngreater than 100:
aselect='gt(samples_n\,100)'
- Create a mosaic of the first scenes, iconic behaviour honestly:
ffmpeg -i video.avi -vf select='gt(scene\,0.4)',scale=160:120,tile -frames:v 1 preview.png
Comparing scene against a value somewhere between 0.3 and 0.5 is generally a sane choice. โจ
- Send the even and odd frames to separate outputs, then compose them back together:
select=n=2:e='mod(n, 2)+1' [odd][even]; [odd] pad=h=2*ih [tmp]; [tmp][even] overlay=y=h
- Select the useful frames out of an
ffconcatfile that's using inpoints and outpoints, but where the source files are not intra-frame only:
ffmpeg -copyts -vsync 0 -segment_time_metadata 1 -i input.ffconcat -vf select=concatdec_select -af aselect=concatdec_select output.avi
sendcmd, asendcmd
Okay so these two literally just send commands to the other filters chilling in the filtergraph. ๐จ
They read commands and pass them along to other filters in the filtergraph. sendcmd has to be wedged between two video filters, and asendcmd has to be wedged between two audio filters โ but other than that, they act exactly the same. Twins. ๐
You can hand over the commands in the filter arguments via the commands option, or in a file named by the filename option.
These filters accept the following options:
commands,cโ sets the commands that get read and sent to the other filters.filename,fโ sets the filename of the commands that get read and sent to the other filters.
Commands syntax
A commands description is basically a sequence of interval specs, each one holding a list of commands to fire when a particular event related to that interval goes down. The event is typically the current frame time entering or leaving a given time interval. ๐ฐ๏ธ
An interval is specified with this syntax:
<START>[-<END>] <COMMANDS>;
The time interval is defined by the START and END times. END is optional and defaults to the maximum time.
The current frame time counts as inside the specified interval if it's included in the interval [START, END) โ meaning the time is greater or equal to START and less than END.
COMMANDS is a sequence of one or more command specs separated by ",", all relating to that interval. The syntax of a single command spec is:
[<FLAGS>] <TARGET> <COMMAND> <ARG>
FLAGS is optional and specifies which type of events relating to the time interval actually enable sending that command. It has to be a non-null sequence of identifier flags separated by "+" or "|" and wrapped in "[" and "]".
The following flags are recognized: ๐ฉ
enterโ the command is sent when the current frame timestamp enters the specified interval. In other words: the previous frame timestamp was not in the interval and the current one is.leaveโ the command is sent when the current frame timestamp leaves the specified interval. In other words: the previous frame timestamp was in the interval and the current one is not.exprโ the commandARGis interpreted as an expression, and the result of that expression gets passed asARG.
The expression is evaluated through the eval API and can contain these constants: ๐งฎ
POSโ original position in the file of the frame, or undefined if it's undefined for the current frame. Deprecated, do not use. ๐ซPTSโ the presentation timestamp in input.Nโ the count of the input frame for video or audio, starting from0.Tโ the time in seconds of the current frame.TSโ the start time in seconds of the current command interval.TEโ the end time in seconds of the current command interval.TIโ the interpolated time of the current command interval,TI = (T - TS) / (TE - TS).Wโ the video frame width.Hโ the video frame height.
If FLAGS isn't specified, a default value of "[enter]" is assumed.
TARGET specifies the target of the command โ usually the name of the filter class or a specific filter instance name.
COMMAND specifies the name of the command for the target filter.
ARG is optional and specifies the optional list of arguments for the given COMMAND.
Between one interval spec and the next, whitespace โ or sequences of characters starting with "#" all the way to the end of the line โ is ignored, and you can absolutely use it to annotate comments. ๐
A simplified BNF description of the commands specification syntax, for the girlies who love grammar:
<COMMAND_FLAG> ::= "enter" | "leave"
<COMMAND_FLAGS> ::= <COMMAND_FLAG> [(+|"|")<COMMAND_FLAG>]
<COMMAND> ::= ["[" <COMMAND_FLAGS> "]"] <TARGET> <COMMAND> [<ARG>]
<COMMANDS> ::= <COMMAND> [,<COMMANDS>]
<INTERVAL> ::= <START>[-<END>] <COMMANDS>
<INTERVALS> ::= <INTERVAL>[;<INTERVALS>]
Examples
- Specify an audio tempo change at second 4:
asendcmd=c='4.0 atempo tempo 1.5',atempo
- Target a specific filter instance:
asendcmd=c='4.0 atempo@my tempo 1.5',atempo@my
- Specify a list of
drawtextandhuecommands in a file.
# show text in the interval 5-10
5.0-10.0 [enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=hello world',
[leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=';
# desaturate the image in the interval 15-20
15.0-20.0 [enter] hue s 0,
[enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=nocolor',
[leave] hue s 1,
[leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=color';
# apply an exponential saturation fade-out effect, starting from time 25
25 [enter] hue s exp(25-t)
A filtergraph that lets you read and process the above command list stored in a file test.cmd can be specified like this:
sendcmd=f=test.cmd,drawtext=fontfile=FreeSerif.ttf:text='',hue
setpts, asetpts
Change the PTS (presentation timestamp) of the input frames. โฑ๏ธ
setpts does its thing on video frames, asetpts does it on audio frames.
This filter accepts the following options:
exprโ the expression that gets evaluated for each frame to construct its timestamp.strip_fps(video only) โ boolean option that decides whether the original framerate and frame duration metadata gets unset. If you set it to true, be advised that you really should explicitly specify a sane frame rate if the output is being sent to a constant frame rate muxer. Default is"false". โ ๏ธ
The expression is evaluated through the eval API and can contain these constants:
FRAME_RATE,FRโ frame rate, only defined for constant frame-rate video.PTSโ the presentation timestamp in input.Nโ the count of the input frame for video, or the number of consumed samples not including the current frame for audio, starting from0.NB_CONSUMED_SAMPLESโ the number of consumed samples, not including the current frame (only audio).NB_SAMPLES,Sโ the number of samples in the current frame (only audio).SAMPLE_RATE,SRโ the audio sample rate.STARTPTSโ the PTS of the first frame.STARTTโ the time in seconds of the first frame.INTERLACEDโ state whether the current frame is interlaced.Tโ the time in seconds of the current frame.POSโ original position in the file of the frame, or undefined if it's undefined for the current frame; deprecated, do not use. ๐ซPREV_INPTSโ the previous input PTS.PREV_INTโ previous input time in seconds.PREV_OUTPTSโ the previous output PTS.PREV_OUTTโ previous output time in seconds.RTCTIMEโ the wallclock (RTC) time in microseconds. This is deprecated, usetime(0)instead.RTCSTARTโ the wallclock (RTC) time at the start of the movie, in microseconds.TBโ the timebase of the input timestamps.T_CHANGEโ time of the first frame after the command was applied, or the time of the first frame if there were no commands.
Examples
- Start counting PTS from zero:
setpts=PTS-STARTPTS
- Apply a fast motion effect:
setpts=0.5*PTS
- Apply a slow motion effect:
setpts=2.0*PTS
- Set a fixed rate of 25 frames per second:
setpts=N/(25*TB)
- Apply a random jitter effect of +/-100 TB units:
setpts=PTS+randomi(0, -100\,100)
- Set a fixed rate of 25 fps with some jitter:
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
- Apply an offset of 10 seconds to the input PTS:
setpts=PTS+10/TB
- Generate timestamps from a "live source" and rebase them onto the current timebase:
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
- Generate timestamps by counting samples:
asetpts=N/SR/TB
Commands
Both filters support all of the options above as commands. ๐
setrange
Force the color range of the output video frame. ๐
The setrange filter just marks the color range property on the output frames. It does not change the input frame at all โ it only sets the corresponding property, which then affects how the frame gets treated by the filters that come after it.
The filter accepts the following options:
rangeโ sets the color range property, and the available values are:autoโ keep the same color range property.unspecified,unknownโ set the color range as unspecified.limited,tv,mpegโ set the color range as limited.full,pc,jpegโ set the color range as full.
settb, asettb
Timebase queen behavior โ this sets the timebase used for output frame timestamps. Itโs mainly useful for testing timebase configuration, iykyk.
It accepts these parameters:
expr,tbโ the expression that gets evaluated into the output timebase.
The value for tb is an arithmetic expression representing a rational. The expression can contain the constants AVTB (the default timebase), intb (the input timebase), and sr (the sample rate, audio only). Default value is "intb".
Examples
- Set the timebase to 1/25:
settb=expr=1/25
- Set the timebase to 1/10:
settb=expr=0.1
- Set the timebase to 1001/1000:
settb=1+0.001
- Set the timebase to 2*intb:
settb=2*intb
- Set the default timebase value:
settb=AVTB
showcqt
Bestie, itโs giving spectrum visualizer โ this converts input audio into a video output that represents the frequency spectrum logarithmically using the Brown-Puckette constant Q transform algorithm with direct frequency domain coefficient calculation (but the transform itself is not really constant Q, instead the Q factor is actually variable/clamped), with musical tone scale, from E0 to D#10. ๐
The filter accepts the following options:
size,sโ specify the video size for the output. It must be even. For the syntax of this option, check the"Video size"section in theffmpeg-utilsmanual. Default value is"1920x1080".fps,rate,rโ set the output frame rate. Default value is25.bar_hโ set the bargraph height. It must be even. Default value is-1, which computes the bargraph height automatically.axis_hโ set the axis height. It must be even. Default value is-1, which computes the axis height automatically.sono_hโ set the sonogram height. It must be even. Default value is-1, which computes the sonogram height automatically.fullhdโ set the fullhd resolution. This option is deprecated, usesize,sinstead. Default value is1.sono_v,volumeโ specify the sonogram volume expression. It can contain variables:bar_vโ thebar_vevaluated expression.frequency,freq,fโ the frequency where it is evaluated.timeclamp,tcโ the value of thetimeclampoption.
And functions:
a_weighting(f)โ A-weighting of equal loudness.b_weighting(f)โ B-weighting of equal loudness.c_weighting(f)โ C-weighting of equal loudness.
Default value is 16.
bar_v,volume2โ specify the bargraph volume expression. It can contain variables:sono_vโ thesono_vevaluated expression.frequency,freq,fโ the frequency where it is evaluated.timeclamp,tcโ the value of thetimeclampoption.
And functions:
a_weighting(f)โ A-weighting of equal loudness.b_weighting(f)โ B-weighting of equal loudness.c_weighting(f)โ C-weighting of equal loudness.
Default value is "sono_v".
sono_g,gammaโ specify the sonogram gamma. Lower gamma makes the spectrum more contrast, higher gamma makes the spectrum have more range. Default value is3. Acceptable range is[1, 7].bar_g,gamma2โ specify the bargraph gamma. Default value is1. Acceptable range is[1, 7].bar_tโ specify the bargraph transparency level. Lower value makes the bargraph sharper. Default value is1. Acceptable range is[0, 1].timeclamp,tcโ specify the transform timeclamp. At low frequency, there is a trade-off between accuracy in time domain and frequency domain. Iftimeclampis lower, an event in time domain is represented more accurately (such as fast bass drum), otherwise an event in frequency domain is represented more accurately (such as bass guitar). Acceptable range is[0.002, 1]. Default value is0.17.attackโ set attack time in seconds. The default is0(disabled). Otherwise, it limits future samples by applying asymmetric windowing in time domain, useful when low latency is required. Accepted range is[0, 1].basefreqโ specify the transform base frequency. Default value is20.01523126408007475, which is frequency 50 cents below E0. Acceptable range is[10, 100000].endfreqโ specify the transform end frequency. Default value is20495.59681441799654, which is frequency 50 cents above D#10. Acceptable range is[10, 100000].coeffclampโ this option is deprecated and ignored.tlengthโ specify the transform length in time domain. Use this option to control the accuracy trade-off between time domain and frequency domain at every frequency sample. It can contain variables:frequency,freq,fโ the frequency where it is evaluated.timeclamp,tcโ the value of thetimeclampoption.
Default value is "384*tc/(384+tc*f)".
countโ specify the transform count for every video frame. Default value is6. Acceptable range is[1, 30].fcountโ specify the transform count for every single pixel. Default value is0, which makes it computed automatically. Acceptable range is[0, 10].fontfileโ specify the font file for use with freetype to draw the axis. If not specified, use embedded font. Note that drawing with font file or embedded font is not implemented with custombasefreqandendfreq, useaxisfileoption instead.fontโ specify fontconfig pattern. This has lower priority thanfontfile. The":"in the pattern may be replaced by"|"to avoid unnecessary escaping.fontcolorโ specify font color expression. This is an arithmetic expression that should return integer value0xRRGGBB. It can contain variables:frequency,freq,fโ the frequency where it is evaluated.timeclamp,tcโ the value of thetimeclampoption.
And functions:
midi(f)โ midi number of frequencyf, some midi numbers: E0(16), C1(24), C2(36), A4(69).r(x),g(x),b(x)โ red, green, and blue value of intensityx.
Default value is "st(0, (midi(f)-59.5)/12); st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0)); r(1-ld(1)) + b(ld(1))".
axisfileโ specify image file to draw the axis. This option overrides thefontfileandfontcoloroption.axis,textโ enable/disable drawing text to the axis. If it is set to0, drawing to the axis is disabled, ignoring thefontfileandaxisfileoption. Default value is1.cspโ set colorspace. The accepted values are:unspecifiedโ Unspecified (default).bt709โ BT.709.fccโ FCC.bt470bgโ BT.470BG or BT.601-6 625.smpte170mโ SMPTE-170M or BT.601-6 525.smpte240mโ SMPTE-240M.bt2020nclโ BT.2020 with non-constant luminance.
cschemeโ set spectrogram color scheme. This is a list of floating point values with format"left_r|left_g|left_b|right_r|right_g|right_b". The default is"1|0.5|0|0|0.5|1".
Examples
- Playing audio while showing the spectrum:
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
- Same as above, but with frame rate 30 fps:
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
- Playing at 1280x720:
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=s=1280x720:count=4 [out0]'
- Disable sonogram display:
sono_h=0
- A1 and its harmonics: A1, A2, (near)E3, A3:
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
asplit[a][out1]; [a] showcqt [out0]'
- Same as above, but with more accuracy in frequency domain:
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
- Custom volume:
bar_v=10:sono_v=bar_v*a_weighting(f)
- Custom gamma, now spectrum is linear to the amplitude:
bar_g=2:sono_g=2
- Custom tlength equation:
tc=0.33:tlength='st(0,0.17); 384*tc / (384 / ld(0) + tc*f /(1-ld(0))) + 384*tc / (tc*f / ld(0) + 384 /(1-ld(0)))'
- Custom fontcolor and fontfile, C-note is colored green, others are colored blue:
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))':fontfile=myfont.ttf
- Custom font using fontconfig:
font='Courier New,Monospace,mono|bold'
- Custom frequency range with custom axis using image file:
axisfile=myaxis.png:basefreq=40:endfreq=10000
showcwt
Wavelet era โ this converts input audio to video output representing the frequency spectrum using Continuous Wavelet Transform and Morlet wavelet. ๐ฆ
The filter accepts the following options:
size,sโ specify the video size for the output. For the syntax of this option, check the"Video size"section in theffmpeg-utilsmanual. Default value is"640x512".rate,rโ set the output frame rate. Default value is25.scaleโ set the frequency scale used. Allowed values are:linearlogbarkmelerbssqrtcbrtqdrtfm
Default value is "linear".
iscaleโ set the intensity scale used. Allowed values are:linearlogsqrtcbrtqdrt
Default value is "log".
minโ set the minimum frequency that will be used in output. Default is20 Hz.maxโ set the maximum frequency that will be used in output. Default is20000 Hz. The real frequency upper limit depends on input audioโs sample rate, and such will be enforced on this value when it is set to a value greater than Nyquist frequency.iminโ set the minimum intensity that will be used in output.imaxโ set the maximum intensity that will be used in output.logbโ sets the logarithmic basis for brightness strength when those calculated magnitude values get mapped to pixel values โจ allowed range is0to1, and the default is0.0001(yes, tiny, that's the point).deviationโ sets the frequency deviation ๐ lower values than1are more frequency oriented, while higher values than1are more time oriented. Allowed range is0to10, default1.ppsโ sets the number of pixel output per each second in one row ๐ allowed range is1to1024, default64.modeโ sets the output visual mode, bestie. allowed values are:magnitudeโ show magnitude.phaseโ show only phase.magphaseโ show combination of magnitude and phase. Magnitude is mapped to brightness and phase to color. (iconic combo tbh ๐ )channelโ show unique color per channel magnitude.stereoโ show unique color per stereo difference.
Default value is "magnitude".
slideโ sets the output slide method. allowed values are:replacescrollframe
directionโ sets the direction method for the output slide method. allowed values are:lrโ direction from left to right.rlโ direction from right to left.udโ direction from up to down.duโ direction from down to up.
barโ sets the ratio of bargraph display to display size. Default is0.rotationโ sets color rotation, must be in[-1.0, 1.0]range. Default value is0.
showfreqs</p> ๐
Converts input audio into a video output representing the audio power spectrum. Audio amplitude is on the Y-axis while frequency is on the X-axis โ like a little graph of your sound's whole personality ๐โจ
The filter accepts the following options:
size,sโ specify size of video. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. Default is"1024x512".rate,rโ set video rate. Default is25.modeโ set display mode. This sets how each frequency bin will be represented. It accepts the following values:linebardot
Default is "bar".
ascaleโ set amplitude scale. It accepts the following values:linโ linear scale.sqrtโ square root scale.cbrtโ cubic root scale.logโ logarithmic scale.
Default is "log".
fscaleโ set frequency scale. It accepts the following values:linโ linear scale.logโ logarithmic scale.rlogโ reverse logarithmic scale.
Default is "lin".
win_sizeโ set window size. Allowed range is from16to65536. Default is2048.win_funcโ set windowing function. It accepts the following values:
rect, bartlett, hanning, hamming, blackman, welch, flattop, bharris, bnuttall, bhann, sine, nuttall, lanczos, gauss, tukey, dolph, cauchy, parzen, poisson, bohman, kaiser
Default is "hanning".
overlapโ set window overlap. In range[0, 1]. Default is1, which means optimal overlap for the selected window function will be picked ๐ฏaveragingโ set time averaging. Setting this to0will display current maximal peaks. Default is1, which means time averaging is disabled.colorsโ specify list of colors separated by space or by'|'which will be used to draw channel frequencies. Unrecognized or missing colors will be replaced by white color. (rude but ok ๐)cmodeโ set channel display mode. It accepts the following values:combinedseparate
Default is "combined".
minampโ set minimum amplitude used in"log"amplitude scaler.dataโ set data display mode. It accepts the following values:magnitudephasedelay
Default is "magnitude".
channelsโ set channels to use when processing audio. By default all are processed.
showspatial ๐ฆ
Converts stereo input audio into a video output representing the spatial relationship between two channels ๐โจ it's giving "I can literally see the stereo field" energy.
The filter accepts the following options:
size,sโ specify the video size for the output. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. Default value is"512x512".win_sizeโ set window size. Allowed range is from1024to65536. Default size is4096.win_funcโ set window function. It accepts the following values:
rect, bartlett, hann, hanning, hamming, blackman, welch, flattop, bharris, bnuttall, bhann, sine, nuttall, lanczos, gauss, tukey, dolph, cauchy, parzen, poisson, bohman, kaiser
Default value is "hann".
rate,rโ set output framerate.
showspectrum ๐ธ
Converts input audio into a video output representing the audio frequency spectrum. This is the one everybody screenshots for thumbnails, ngl ๐ โจ
The filter accepts the following options:
size,sโ specify the video size for the output. For the syntax of this option, check the "Video size" section in theffmpeg-utilsmanual. Default value is"640x512".slideโ specify how the spectrum should slide along the window. It accepts the following values:replaceโ the samples start again on the left when they reach the right.scrollโ the samples scroll from right to left.fullframeโ frames are only produced when the samples reach the right.rscrollโ the samples scroll from left to right.lreplaceโ the samples start again on the right when they reach the left.
Default value is "replace".
modeโ specify display mode. It accepts the following values:combinedโ all channels are displayed in the same row.separateโ all channels are displayed in separate rows.
Default value is combined.
colorโ specify display color mode. It accepts the following values:channelโ each channel is displayed in a separate color.intensityโ each channel is displayed using the same color scheme.rainbowโ each channel is displayed using the rainbow color scheme.morelandโ each channel is displayed using the moreland color scheme.nebulaeโ each channel is displayed using the nebulae color scheme.fireโ each channel is displayed using the fire color scheme.fieryโ each channel is displayed using the fiery color scheme.fruitโ each channel is displayed using the fruit color scheme.coolโ each channel is displayed using the cool color scheme.magmaโ each channel is displayed using the magma color scheme.greenโ each channel is displayed using the green color scheme.viridisโ each channel is displayed using the viridis color scheme.plasmaโ each channel is displayed using the plasma color scheme.cividisโ each channel is displayed using the cividis color scheme.terrainโ each channel is displayed using the terrain color scheme.
Default value is channel.
scaleโ specify scale used for calculating intensity color values. It accepts the following values:linโ linearsqrtโ square root, defaultcbrtโ cubic rootlogโ logarithmic4thrtโ 4th root5thrtโ 5th root
Default value is sqrt.
fscaleโ specify frequency scale. It accepts the following values:linโ linearlogโ logarithmic
Default value is lin.
saturationโ set saturation modifier for displayed colors. Negative values provide alternative color scheme.0is no saturation at all. Saturation must be in[-10.0, 10.0]range. Default value is1.win_funcโ set window function. It accepts the following values:
rect, bartlett, hann, hanning, hamming, blackman, welch, flattop, bharris, bnuttall, bhann, sine, nuttall, lanczos, gauss, tukey, dolph, cauchy, parzen, poisson, bohman, kaiser
Default value is "hann".
orientationโ set orientation of time vs frequency axis. Can be"vertical"or"horizontal". Default is"vertical".overlapโ set ratio of overlap window. Default value is0. When value is1overlap is set to recommended size for specific window function currently used.gainโ set scale gain for calculating intensity color values. Default value is1.dataโ set which data to display. Can be"magnitude", default, or"phase", or unwrapped phase:"uphase".rotationโ set color rotation, must be in[-1.0, 1.0]range. Default value is0.startโ set start frequency from which to display spectrogram. Default is0.stopโ set stop frequency to which to display spectrogram. Default is0.fpsโ set upper frame rate limit. Default is"auto", unlimited ๐โโ๏ธ๐จlegendโ draw time and frequency axes and legends. Default is disabled.drangeโ set dynamic range used to calculate intensity color values. Default is120dBFS. Allowed range is from10to200.limitโ set upper limit of input audio samples volume in dBFS. Default is0dBFS. Allowed range is from-100to100.opacityโ set opacity strength when using pixel format output with alpha component.
The usage is very similar to the showwaves filter; see the examples in that section ๐
Examples โจ
- Large window with logarithmic color scaling:
showspectrum=s=1280x480:scale=log
- Complete example for a colored and sliding spectrum per channel using
ffplay:
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
[a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
showspectrumpic ๐
Converts input audio into a single video frame, representing the audio frequency spectrum โ one still image of the whole vibe check, no scrolling ๐ผ๏ธโจ
The filter accepts the following options:
size,sโ the output video size, obvi ๐ For the syntax, go peek at the "Video size" section in theffmpeg-utilsmanual. Default value is4096x2048โ she's large, she's in charge.modeโ sets the display mode. It accepts these values:combinedโ all the channels are displayed in the same rowseparateโ all the channels are displayed in separate rows Default value iscombined.
colorโ sets the display color mode. It accepts:channelโ each channel is displayed in a separate colorintensityโ each channel is displayed using the same color schemerainbowโ each channel is displayed using the rainbow color schememorelandโ each channel is displayed using the moreland color schemenebulaeโ each channel is displayed using the nebulae color schemefireโ each channel is displayed using the fire color scheme ๐ฅfieryโ each channel is displayed using the fiery color schemefruitโ each channel is displayed using the fruit color scheme ๐coolโ each channel is displayed using the cool color schememagmaโ each channel is displayed using the magma color schemegreenโ each channel is displayed using the green color schemeviridisโ each channel is displayed using the viridis color schemeplasmaโ each channel is displayed using the plasma color schemecividisโ each channel is displayed using the cividis color schemeterrainโ each channel is displayed using the terrain color scheme Default value isintensity.
scaleโ sets the scale used for calculating intensity color values. It accepts:linโ linearsqrtโ square root, defaultcbrtโ cubic rootlogโ logarithmic4thrtโ 4th root5thrtโ 5th root Default value islog. (yes bestie, the page says both things. I don't make the rules, I just deliver them ๐ )
fscaleโ sets the frequency scale. It accepts:linโ linearlogโ logarithmic Default value islin.
saturationโ sets the saturation modifier for the displayed colors. Negative values give you an alternative color scheme, and0is no saturation at all. Gotta stay in the[-10.0, 10.0]range, no cap. Default value is1.win_funcโ sets the window function. It accepts:
rect
bartlett
hann
hanning
hamming
blackman
welch
flattop
bharris
bnuttall
bhann
sine
nuttall
lanczos
gauss
tukey
dolph
cauchy
parzen
poisson
bohman
kaiser
Default value is hann.
orientationโ sets the orientation of the time vs frequency axis. Can beverticalorhorizontal. Default isvertical.gainโ sets the scale gain for calculating intensity color values. Default value is1.legendโ draws time and frequency axes and legends. Default is enabled. โจrotationโ sets color rotation, must be in the[-1.0, 1.0]range. Default value is0.startโ sets the start frequency from which to display the spectrogram. Default is0.stopโ sets the stop frequency to which to display the spectrogram. Default is0.drangeโ sets the dynamic range used to calculate intensity color values. Default is120 dBFS. Allowed range is from10to200.limitโ sets the upper limit of input audio samples volume in dBFS. Default is0 dBFS. Allowed range is from-100to100.opacityโ sets the opacity strength when you're using a pixel format output with an alpha component.
Examples
- Extract an audio spectrogram of a whole audio track into a
1024x1024picture usingffmpeg:
ffmpeg -i audio.flac -lavfi showspectrumpic=s=1024x1024 spectrogram.png
๐ showvolume
Converts input audio volume into a video output. Literally turning vibes into visuals.
The filter accepts the following options:
rate,rโ sets the video rate.bโ sets the border width, allowed range is[0, 5]. Default is1.wโ sets the channel width, allowed range is[80, 8192]. Default is400.hโ sets the channel height, allowed range is[1, 900]. Default is20.fโ sets the fade, allowed range is[0, 1]. Default is0.95.cโ sets the volume color expression. The expression can use these variables:VOLUMEโ current max volume of the channel in dBPEAKโ current peakCHANNELโ current channel number, starting from0
tโ if set, displays channel names. Default is enabled.vโ if set, displays volume values. Default is enabled.oโ sets the orientation, can be horizontal:hor vertical:v, default ish.sโ sets the step size, allowed range is[0, 5]. Default is0, which means the step is disabled.pโ sets the background opacity, allowed range is[0, 1]. Default is0.mโ sets the metering mode, can be peak:por rms:r, default isp.dsโ sets the display scale, can be linear:linor log:log, default islin.dmโ in second. If set to> 0., displays a line for the max level in the previous seconds. default is disabled:0.dmcโ the color of the max line. Use this when thedmoption is set to> 0. default is:orange๐
๐ showwaves
Converts input audio to a video output, representing the sample waves. It's giving "sound, but make it visible" ๐ฆ
The filter accepts the following options:
size,sโ the video size for the output. For the syntax, check the "Video size" section in theffmpeg-utilsmanual. Default value is600x240.modeโ sets the display mode. Available values:pointโ draws a point for each samplelineโ draws a vertical line for each samplep2pโ draws a point for each sample and a line between themclineโ draws a centered vertical line for each sample Default value ispoint.
nโ sets the number of samples which are printed on the same column. A larger value will decrease the frame rate. Must be a positive integer. Heads up bestie: this option can be set only if the value forrateis not explicitly specified.rate,rโ sets the (approximate) output frame rate. This is done by setting thenoption. Default value is25.split_channelsโ sets whether channels should be drawn separately or overlap. Default value is0.colorsโ sets colors separated by'|'which are going to be used for drawing each channel. ๐scaleโ sets the amplitude scale. Available values:linโ linearlogโ logarithmicsqrtโ square rootcbrtโ cubic root Default is linear.
drawโ sets the draw mode. This is mostly useful to set for highn. Available values:scaleโ scales pixel values for each drawn samplefullโ draws every sample directly Default value isscale.
Examples
- Output the input file audio and the corresponding video representation at the same time:
amovie=a.mp3,asplit[out0],showwaves[out1]
- Create a synthetic signal and show it with
showwaves, forcing a frame rate of 30 frames per second:
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
๐ผ showwavespic
Converts input audio into a single video frame, representing the sample waves. One frame, one iconic lil snapshot ๐
The filter accepts the following options:
size,sโ the video size for the output. For the syntax, check the "Video size" section in theffmpeg-utilsmanual. Default value is600x240.split_channelsโ sets whether channels should be drawn separately or overlap. Default value is0.colorsโ sets colors separated by'|'which are going to be used for drawing each channel.scaleโ sets the amplitude scale. Available values:linโ linearlogโ logarithmicsqrtโ square rootcbrtโ cubic root Default is linear.
drawโ sets the draw mode. Available values:scaleโ scales pixel values for each drawn samplefullโ draws every sample directly Default value isscale.
filterโ sets the filter mode. Available values:averageโ uses average sample values for each drawn samplepeakโ uses peak sample values for each drawn sample Default value isaverage.
Examples
- Extract a channel split representation of the waveform of a whole audio track into a
1024x800picture usingffmpeg:
ffmpeg -i audio.flac -lavfi showwavespic=split_channels=1:s=1024x800 waveform.png
๐ sidedata, asidedata
Deletes frame side data, or selects frames based on it. It's the "block and/or pick" filter of the friend group.
This filter accepts the following options:
modeโ sets the mode of operation of the filter. Can be one of the following:selectโ selects every frame with side data oftypedeleteโ deletes side data oftype. Iftypeis not set, deletes all side data in the frame
typeโ sets the side data type used with all modes. Must be set forselectmode. Possible values are:
PANSCAN
A53_CC
STEREO3D
MATRIXENCODING
DOWNMIX_INFO
REPLAYGAIN
DISPLAYMATRIX
AFD
MOTION_VECTORS
SKIP_SAMPLES
AUDIO_SERVICE_TYPE
MASTERING_DISPLAY_METADATA
GOP_TIMECODE
SPHERICAL
CONTENT_LIGHT_LEVEL
ICC_PROFILE
S12M_TIMECODE
DYNAMIC_HDR_PLUS
REGIONS_OF_INTEREST
VIDEO_ENC_PARAMS
SEI_UNREGISTERED
FILM_GRAIN_PARAMS
DETECTION_BOUNDING_BOXES
DETECTION_BBOXES
DOVI_RPU_BUFFER
DOVI_METADATA
DYNAMIC_HDR_VIVID
AMBIENT_VIEWING_ENVIRONMENT
VIDEO_HINT
๐งช spectrumsynth
Synthesizes audio from 2 input video spectrums โ the first input stream represents magnitude across time and the second represents phase across time. The filter will transform from the frequency domain as displayed in the videos back to the time domain as presented in the audio output. It's literally a glow-up in reverse, and it ate ๐ฅ๐
This filter is basically the reverse-engineering queen โ she's built first and foremost to undo processed showspectrum filter output, but she can also synthesize sound from other spectrograms too ๐. Ngl though, in that case the results are going to be poor if the phase data isn't available, because then the phase data has to be recreated, and usually it's just recreated from random noise ๐ญ. For best results use gray only output (that's "channel" color mode in the showspectrum filter) and "log" scale for magnitude video and "lin" scale for phase video, bestie. To produce phase, for the 2nd video, use the "data" option. Input videos should generally use "fullframe" slide mode because that saves resources needed for decoding video โ lowkey efficient ๐
.
The filter accepts the following options:
sample_rateโ specify sample rate of output audio, since the sample rate of the audio the spectrum was generated from may differ โจchannelsโ set the number of channels represented in the input video spectrumsscaleโ set the scale that was used when generating the magnitude input spectrum. Can be"lin"or"log". Default is"log"๐ฆslideโ set the slide that was used when generating the input spectrums. Can be"replace","scroll","fullframe"or"rscroll". Default is"fullframe"win_funcโ set the window function used for resynthesisoverlapโ set the window overlap, in range"[0, 1]". Default is1, which means the optimal overlap for the selected window function will be picked ๐orientationโ set the orientation of the input videos. Can be"vertical"or"horizontal". Default is"vertical"
โจ Examples โจ
- First create magnitude and phase videos from audio โ assuming the audio is stereo with
44100sample rate โ then resynthesize those videos back to audio withspectrumsynth๐:
ffmpeg -i input.flac -lavfi showspectrum=mode=separate:scale=log:overlap=0.875:color=channel:slide=fullframe:data=magnitude -an -c:v rawvideo magnitude.nut
ffmpeg -i input.flac -lavfi showspectrum=mode=separate:scale=lin:overlap=0.875:color=channel:slide=fullframe:data=phase -an -c:v rawvideo phase.nut
ffmpeg -i magnitude.nut -i phase.nut -lavfi spectrumsynth=channels=2:sample_rate=44100:win_func=hann:overlap=0.875:slide=fullframe output.flac
๐ฆ split, asplit ๐ฆ
Split the input into several identical outputs โ she's giving "cloning machine, but make it cute" โจ.
"asplit" works with audio input, and "split" with video.
The filter accepts a single parameter which specifies the number of outputs. If unspecified, it defaults to 2 ๐
.
โจ Examples โจ
- Create two separate outputs from the same input:
[in] split [out0][out1]
- To create
3or more outputs, you need to specify the number of outputs, like in:
[in] asplit=3 [out0][out1][out2]
- Create two separate outputs from the same input, one cropped and one padded ๐:
[in] split [splitout1][splitout2];
[splitout1] crop=100:100:0:0 [cropout];
[splitout2] pad=200:200:100:100 [padout];
- Create
5copies of the input audio withffmpeg:
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
๐ zmq, azmq ๐
Receive commands sent through a libzmq client, and forward them to filters in the filtergraph ๐ฅ.
"zmq" and "azmq" work as pass-through filters. "zmq" must be inserted between two video filters, and "azmq" between two audio filters. Both are capable of sending messages to any filter type โ versatile icons, honestly ๐.
To enable these filters you need to install the libzmq library and headers and configure FFmpeg with --enable-libzmq.
For more information about libzmq see: http://www.zeromq.org/
The "zmq" and "azmq" filters work as a libzmq server, which receives messages sent through a network interface defined by the bind_address (or the abbreviation "b") option. Default value of this option is tcp://localhost:5555. You may want to alter this value to your needs, but do not forget to escape any ':' signs (see filtergraph escaping) ๐.
The received message must be in the form:
<TARGET> <COMMAND> [<ARG>]
TARGET specifies the target of the command, usually the name of the filter class or a specific filter instance name. The default filter instance name uses the pattern Parsed_<filter_name>_<index>, but you can override this by using the filter_name@id syntax (see Filtergraph syntax) โจ.
COMMAND specifies the name of the command for the target filter.
ARG is optional and specifies the optional argument list for the given COMMAND.
Upon reception, the message is processed and the corresponding command is injected into the filtergraph. Depending on the result, the filter will send a reply to the client, adopting the format:
<ERROR_CODE> <ERROR_REASON>
<MESSAGE>
MESSAGE is optional.
โจ Examples โจ
Look at tools/zmqsend for an example of a zmq client which can be used to send commands processed by these filters ๐ซถ.
Consider the following filtergraph generated by ffplay. In this example the last overlay filter has an instance name. All other filters will have default instance names.
ffplay -dumpgraph 1 -f lavfi "
color=s=100x100:c=red [l];
color=s=100x100:c=blue [r];
nullsrc=s=200x100, zmq [bg];
[bg][l] overlay [bg+l];
[bg+l][r] overlay@my=x=100 "
To change the color of the left side of the video, the following command can be used:
echo Parsed_color_0 c yellow | tools/zmqsend
To change the right side:
echo Parsed_color_1 c pink | tools/zmqsend
To change the position of the right side:
echo overlay@my x 150 | tools/zmqsend
๐ MULTIMEDIA SOURCES ๐
okay so below is the rundown of the multimedia sources we have rn, bestie ๐
๐ amovie
literally the same as the movie source, except it picks an audio stream by default instead of video. that's it, that's the whole thing. she's movie's audio-first sister ๐
๐ฆ avsynctest
generates an Audio/Video Sync Test. yes bestie, a whole test stream, built right in โจ
the generated stream periodically shows a flash video frame and emits a beep in the audio. super useful for inspecting A/V sync issues โ like, if the beep and the flash don't line up, you know something's off ๐ญ
it accepts the following options:
size,sโ sets the output video size. default value is"hd720"๐framerate,frโ sets the output video frame rate. default is30.samplerate,srโ sets the output audio sample rate. default value is44100โจamplitude,aโ sets the output audio beep amplitude. default value is0.7.period,pโ sets the output audio beep period in seconds. default value is3.delay,dlโ sets the output video flash delay in number of frames. default value is0.cycle,cโ enables cycling of video delays, by default is disabled.duration,dโ sets the stream output duration. by default duration is unlimited ๐fg,bg,agโ set foreground/background/additional color ๐จ
Commands
this source supports the some above options as commands. (yes, that's the actual wording โ some of the options up there double as commands, iykyk ๐ )
๐ง movie
reads audio and/or video stream(s) out of a movie container. main character energy fr fr.
it accepts the following parameters:
filenameโ the name of the resource to read (not necessarily a file; it can also be a device or a stream accessed through some protocol). so like, it's flexible, she's versatile ๐ธformat_name,fโ specifies the format assumed for the movie to read, and can be either the name of a container or an input device. if not specified, the format is guessed frommovie_nameor by probing ๐seek_point,spโ specifies the seek point in seconds. the frames will be output starting from this seek point. the parameter is evaluated withav_strtod, so the numerical value may be suffixed by an IS postfix. the default value is"0"โจstreams,sโ specifies the streams to read. several streams can be specified, separated by"+". the source will then have as many outputs, in the same order. the syntax is explained in the"Stream specifiers"section in the ffmpeg manual. two special names,"dv"and"da"specify respectively the default (best suited) video and audio stream. default is"dv", or"da"if the filter is called as"amovie"๐stream_index,siโ specifies the index of the video stream to read. if the value is-1, the most suitable video stream will be automatically selected. the default value is"-1". deprecated (so like, don't be doing this anymore bestie ๐). if the filter is called"amovie", it will select audio instead of video.loopโ specifies how many times to read the stream in sequence. if the value is0, the stream will be looped infinitely. default value is"1"๐
heads up bestie: when the movie is looped the source timestamps are not changed, so it will generate non monotonically increasing timestamps. that's a real caveat, not a vibe, ok? ๐
discontinuityโ specifies the time difference between frames above which the point is considered a timestamp discontinuity which is removed by adjusting the later timestamps.dec_threadsโ specifies the number of threads for decoding ๐โโ๏ธformat_optsโ specify format options for the opened file. format options can be specified as a list ofkey=valuepairs separated by':'. the following example shows how to addprotocol_whitelistandprotocol_blacklistoptions:
ffplay -f lavfi
"movie=filename='1.sdp':format_opts='protocol_whitelist=file,rtp,udp\:protocol_blacklist=http'"
it allows overlaying a second video on top of the main input of a filtergraph, as shown in this graph:
input -----------> deltapts0 --> overlay --> output
^
|
movie --> scale--> deltapts1 -------+
Examples
- skip
3.2seconds from the start of the AVI filein.avi, and overlay it on top of the input labelled"in":
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
[in] setpts=PTS-STARTPTS [main];
[main][over] overlay=16:16 [out]
- read from a
video4linux2device, and overlay it on top of the input labelled"in":
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
[in] setpts=PTS-STARTPTS [main];
[main][over] overlay=16:16 [out]
- read the first video stream and the audio stream with id
0x81fromdvd.vob; the video is connected to the pad named"video"and the audio is connected to the pad named"audio":
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
Commands
both movie and amovie support the following commands ๐
seekโ perform seek usingav_seek_frame. the syntax is:seek stream_index|timestamp|flagsstream_index: ifstream_indexis-1, a default stream is selected, andtimestampis automatically converted fromAV_TIME_BASEunits to the stream specifictime_base.timestamp: timestamp inAVStream.time_baseunits or, if no stream is specified, inAV_TIME_BASEunits.flags: flags which select direction and seeking mode.
get_durationโ get movie duration inAV_TIME_BASEunits โฑ๏ธ
๐ EXTERNAL LIBRARIES ๐
FFmpeg can be hooked up with a number of external libraries to add support for more formats. none of them are used by default โ their use has to be explicitly requested by passing the appropriate flags to ./configure. so like, opt-in only, she's not gonna assume ๐ซถ
๐ Alliance for Open Media (AOM)
FFmpeg can make use of the AOM library for AV1 decoding and encoding.
go to <http://aomedia.org/> and follow the instructions for installing the library. then pass --enable-libaom to configure to enable it โจ
๐ฅ AMD AMF/VCE
FFmpeg can use the AMD Advanced Media Framework library for accelerated H.264 and HEVC (only windows) encoding on hardware with Video Coding Engine (VCE).
to enable support you must obtain the AMF framework header files (version 1.4.9+) from <https://github.com/GPUOpen-LibrariesAndSDKs/AMF.git>.
create an AMF/ directory in the system include path. copy the contents of AMF/amf/public/include/ into that directory. then configure FFmpeg with --enable-amf.
initialization of amf encoder occurs in this order: 1) trying to initialize through dx11 (only windows) 2) trying to initialize through dx9 (only windows) 3) trying to initialize through vulkan ๐
to use h.264 (AMD VCE) encoder on linux amdgru-pro version 19.20+ and amf-amdgpu-pro package (amdgru-pro contains, but does not install automatically) are required.
this driver can be installed using amdgpu-pro-install script in official amd driver archive.
๐ฆ AviSynth
FFmpeg can read AviSynth scripts as input. to enable support, pass --enable-avisynth to configure after installing the headers provided by <https://github.com/AviSynth/AviSynthPlus>. AviSynth+ can be configured to install only the headers by either passing -DHEADERS_ONLY:bool=on to the normal CMake-based build system, or by using the supplied GNUmakefile ๐
for Windows, supported AviSynth variants are <http://avisynth.nl> for 32-bit builds and <http://avisynth.nl/index.php/AviSynth+> for 32-bit and 64-bit builds.
for Linux, macOS, and BSD, the only supported AviSynth variant is <https://github.com/AviSynth/AviSynthPlus>, starting with version 3.5. ๐ง
In 2016, AviSynth+ added support for building with GCC. However, due to the eccentricities of Windows' calling conventions, 32-bit GCC builds of AviSynth+ are not compatible with typical 32-bit builds of FFmpeg. ๐ญ By default, FFmpeg assumes compatibility with 32-bit MSVC builds of AviSynth+ since that is the most widely-used and entrenched build configuration. Users can override this and enable support for 32-bit GCC builds of AviSynth+ by passing-DAVSC_WIN32_GCC32to--extra-cflagswhen configuring FFmpeg. 64-bit builds of FFmpeg are not affected, and can use either MSVC or GCC builds of AviSynth+ without any special flags. ๐ AviSynth(+) is loaded dynamically. Distributors can build FFmpeg with--enable-avisynth, and the binaries will work regardless of the end user having AviSynth installed. If/when an end user would like to use AviSynth scripts, then they can install AviSynth(+) and FFmpeg will be able to find and use it to open scripts. slay ๐
๐ Chromaprint
FFmpeg can make use of the Chromaprint library for generating audio fingerprints. pass --enable-chromaprint to configure to enable it. see <https://acoustid.org/chromaprint>.
๐ธ codec2
FFmpeg can make use of the codec2 library for codec2 decoding and encoding. there is currently no native decoder, so libcodec2 must be used for decoding. important detail, don't forget it ๐ซถ
go to <http://freedv.org/>, download Codec 2 source archive. build and install using CMake. Debian users can install the libcodec2-dev package instead. once libcodec2 is installed you can pass --enable-libcodec2 to configure to enable it.
the easiest way to use codec2 is with .c2 files, since they contain the mode information required for decoding. to encode such a file, use a .c2 file extension and give the libcodec2 encoder the -mode option: ffmpeg -i input.wav -mode 700C output.c2. playback is as simple as ffplay output.c2. for a list of supported modes, run ffmpeg -h encoder=libcodec2. raw codec2 files are also supported. to make sense of them the mode in use needs to be specified as a format option: ffmpeg -f codec2raw -mode 1300 -i input.raw output.wav. โจ
๐ dav1d
FFmpeg can make use of the dav1d library for AV1 video decoding.
go to <https://code.videolan.org/videolan/dav1d> and follow the instructions for installing the library. then pass --enable-libdav1d to configure to enable it.
๐ davs2
FFmpeg can make use of the davs2 library for AVS2-P2/IEEE1857.4 video decoding.
go to <https://github.com/pkuvcl/davs2> and follow the instructions for installing the library. then pass --enable-libdavs2 to configure to enable it.
libdavs2 is under the GNU Public License Version 2 or later (see <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html> for details), you must upgrade FFmpeg's license to GPL in order to use it. licensing tea, bestie โ read it before you commit โ๐
โญ uavs3d
FFmpeg can make use of the uavs3d library for AVS3-P2/IEEE1857.10 video decoding.
go to <https://github.com/uavs3/uavs3d> and follow the instructions for installing the library. then pass --enable-libuavs3d to configure to enable it. ๐
Game Music Emu ๐ฎ๐ต
okay so FFmpeg can make use of the Game Music Emu library to read audio from supported video game music file formats โ yes, the chiptune thing, we stan. Pass --enable-libgme to configure to enable it. All the deets live here: <https://bitbucket.org/mpyne/game-music-emu/overview>.
Intel QuickSync Video โก
FFmpeg can use Intel QuickSync Video (QSV) for accelerated decoding and encoding of multiple codecs. To use QSV, FFmpeg must be linked against the libmfx dispatcher, which loads the actual decoding libraries (she's the middle manager of this whole operation, truly).
The dispatcher is open source and can be downloaded from <https://github.com/lu-zero/mfx_dispatch.git>. FFmpeg needs to be configured with the --enable-libmfx option, and pkg-config needs to be able to locate the dispatcher's .pc files. (pkg-config is so picky but we love her.)
Kvazaar ๐
FFmpeg can make use of the Kvazaar library for HEVC encoding.
Go to <https://github.com/ultravideo/kvazaar> and follow the instructions for installing the library. Then pass --enable-libkvazaar to configure to enable it.
LAME ๐ง
FFmpeg can make use of the LAME library for MP3 encoding.
Go to <http://lame.sourceforge.net/> and follow the instructions for installing the library. Then pass --enable-libmp3lame to configure to enable it.
LCEVCdec โจ
FFmpeg can make use of the liblcevc_dec library for LCEVC enhancement layer decoding on supported bitstreams.
Go to <https://github.com/v-novaltd/LCEVCdec> and follow the instructions for installing the library. Then pass --enable-liblcevc-dec to configure to enable it.
fyi bestie, LCEVCdec is under the BSD-3-Clause-Clear License.
libilbc ๐๏ธ
iLBC is a narrowband speech codec that has been made freely available by Google as part of the WebRTC project. libilbc is a packaging friendly copy of the iLBC codec. FFmpeg can make use of the libilbc library for iLBC decoding and encoding.
Go to <https://github.com/TimothyGu/libilbc> and follow the instructions for installing the library. Then pass --enable-libilbc to configure to enable it.
libjxl ๐ผ๏ธ
JPEG XL is an image format intended to fully replace legacy JPEG for an extended period of life. See <https://jpegxl.info/> for more information, and see <https://github.com/libjxl/libjxl> for the library source. You can pass --enable-libjxl to configure in order enable the libjxl wrapper. (yes, "in order enable" โ that's how it's written, we're not fixing it, we're just quoting her ๐)
libvpx ๐ฌ
FFmpeg can make use of the libvpx library for VP8/VP9 decoding and encoding.
Go to <http://www.webmproject.org/> and follow the instructions for installing the library. Then pass --enable-libvpx to configure to enable it.
ModPlug ๐ผ
FFmpeg can make use of this library, originating in Modplug-XMMS, to read from MOD-like music files. See <https://github.com/Konstanty/libmodplug>. Pass --enable-libmodplug to configure to enable it. Tracker kids, this one's for you ๐ซถ
OpenCORE, VisualOn, and Fraunhofer libraries ๐ญ
Spun off Google Android sources, OpenCore, VisualOn and Fraunhofer libraries provide encoders for a number of audio codecs.
โ ๏ธ license check time, bestie, read carefully: OpenCORE and VisualOn libraries are under the Apache License 2.0 (see<http://www.apache.org/licenses/LICENSE-2.0>for details), which is incompatible to the LGPL version 2.1 and GPL version 2. You have to upgrade FFmpeg's license to LGPL version 3 (or if you have enabled GPL components, GPL version 3) by passing--enable-version3to configure in order to use it.
โ ๏ธ and also: the license of the Fraunhofer AAC library is incompatible with the GPL. Therefore, for GPL builds, you have to pass --enable-nonfree to configure in order to use it. To the best of our knowledge, it is compatible with the LGPL.
OpenCORE AMR
FFmpeg can make use of the OpenCORE libraries for AMR-NB decoding/encoding and AMR-WB decoding.
Go to <http://sourceforge.net/projects/opencore-amr/> and follow the instructions for installing the libraries. Then pass --enable-libopencore-amrnb and/or --enable-libopencore-amrwb to configure to enable them.
VisualOn AMR-WB encoder library
FFmpeg can make use of the VisualOn AMR-WBenc library for AMR-WB encoding.
Go to <http://sourceforge.net/projects/opencore-amr/> and follow the instructions for installing the library. Then pass --enable-libvo-amrwbenc to configure to enable it.
Fraunhofer AAC library
FFmpeg can make use of the Fraunhofer AAC library for AAC decoding & encoding.
Go to <http://sourceforge.net/projects/opencore-amr/> and follow the instructions for installing the library. Then pass --enable-libfdk-aac to configure to enable it.
Fraunhofer MPEG-H 3D Audio decoder library
FFmpeg can make use of the Fraunhofer MPEG-H decoder library for MPEG-H 3DA decoding.
Go to <https://github.com/Fraunhofer-IIS/mpeghdec> and follow the instructions for installing the library. Then pass --enable-libmpeghdec --enable-nonfree to configure to enable it.
LC3 library
FFmpeg can make use of the Google LC3 library for LC3 decoding & encoding.
Go to <https://github.com/google/liblc3/> and follow the instructions for installing the library. Then pass --enable-liblc3 to configure to enable it.
OpenH264 ๐
FFmpeg can make use of the OpenH264 library for H.264 decoding and encoding.
Go to <http://www.openh264.org/> and follow the instructions for installing the library. Then pass --enable-libopenh264 to configure to enable it.
ngl for decoding this library is much more limited than the built-in decoder in libavcodec; currently, this library lacks support for decoding B-frames and some other main/high profile features. (It currently only supports constrained baseline profile and CABAC.) Using it is mostly useful for testing and for taking advantage of Cisco's patent portfolio license (<http://www.openh264.org/BINARY_LICENSE.txt>).
OpenJPEG ๐๏ธ
FFmpeg can use the OpenJPEG libraries for decoding/encoding J2K videos. Go to <http://www.openjpeg.org/> to get the libraries and follow the installation instructions. To enable using OpenJPEG in FFmpeg, pass --enable-libopenjpeg to ./configure.
rav1e ๐ฆ
FFmpeg can make use of rav1e (Rust AV1 Encoder) via its C bindings to encode videos. Go to <https://github.com/xiph/rav1e/> and follow the instructions to build the C library. To enable using rav1e in FFmpeg, pass --enable-librav1e to ./configure. Rust girlies rise ๐ซถ
SVT-AV1 ๐
FFmpeg can make use of the Scalable Video Technology for AV1 library for AV1 encoding.
Go to <https://gitlab.com/AOMediaCodec/SVT-AV1/> and follow the instructions for installing the library. Then pass --enable-libsvtav1 to configure to enable it.
SVT-JPEG-XS ๐ธ
FFmpeg can make use of the Scalable Video Technology for JPEG-XS library for JPEG-XS decoding and encoding.
Go to <https://github.com/OpenVisualCloud/SVT-JPEG-XS> and follow the instructions for installing the library. Then pass --enable-libsvtjpegxs to configure to enable it.
TwoLAME ๐ฟ
FFmpeg can make use of the TwoLAME library for MP2 encoding.
Go to <http://www.twolame.org/> and follow the instructions for installing the library. Then pass --enable-libtwolame to configure to enable it.
VapourSynth ๐ซ๏ธ
FFmpeg can read VapourSynth scripts as input. To enable support, pass --enable-vapoursynth to configure. Vapoursynth is detected via pkg-config. Versions 42 or greater supported. See <http://www.vapoursynth.com/>.
๐ okay security moment, listen up: due to security concerns, Vapoursynth scripts will not be autodetected so the input format has to be forced. For ff* CLI tools, add-f vapoursynthbefore the input-i yourscript.vpy.
-f vapoursynth -i yourscript.vpy
x264 ๐ฅ
FFmpeg can make use of the x264 library for H.264 encoding.
Go to <http://www.videolan.org/developers/x264.html> and follow the instructions for installing the library. Then pass --enable-libx264 to configure to enable it.
โ ๏ธ licensing tea: x264 is under the GNU Public License Version 2 or later (see <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html> for details), you must upgrade FFmpeg's license to GPL in order to use it.
x265 ๐๏ธ
FFmpeg can make use of the x265 library for HEVC encoding.
Go to <http://x265.org/developers.html> and follow the instructions for installing the library. Then pass --enable-libx265 to configure to enable it.
โ ๏ธ same energy: x265 is under the GNU Public License Version 2 or later (see <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html> for details), you must upgrade FFmpeg's license to GPL in order to use it.
xavs ๐จ๐ณ
FFmpeg can make use of the xavs library for AVS encoding.
Go to <http://xavs.sf.net/> and follow the instructions for installing the library. Then pass --enable-libxavs to configure to enable it.
xavs2 ๐
FFmpeg can make use of the xavs2 library for AVS2-P2/IEEE1857.4 video encoding.
Go to <https://github.com/pkuvcl/xavs2> and follow the instructions for installing the library. Then pass --enable-libxavs2 to configure to enable it.
โ ๏ธ heads up: libxavs2 is under the GNU Public License Version 2 or later (see <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html> for details), you must upgrade FFmpeg's license to GPL in order to use it.
eXtra-fast Essential Video Encoder (XEVE) ๐๏ธ
FFmpeg can make use of the XEVE library for EVC video encoding.
Go to <https://github.com/mpeg5/xeve> and follow the instructions for installing the XEVE library. Then pass --enable-libxeve to configure to enable it.
eXtra-fast Essential Video Decoder (XEVD) ๐
FFmpeg can make use of the XEVD library for EVC video decoding.
Go to <https://github.com/mpeg5/xevd> and follow the instructions for installing the XEVD library. Then pass --enable-libxevd to configure to enable it.
ZVBI ๐บ
ZVBI is a VBI decoding library which can be used by FFmpeg to decode DVB teletext pages and DVB teletext subtitles.
Go to <http://sourceforge.net/projects/zapping/> and follow the instructions for installing the library. Then pass --enable-libzvbi to configure to enable it.
๐ SUPPORTED FILE FORMATS ๐
You can use the -formats and -codecs options to have an exhaustive list. Like, an actually exhaustive list โ use those, bestie, don't come for me if your fave isn't in the highlights below ๐
๐ File Formats
FFmpeg supports the following file formats through the libavformat library. The columns in the OG table are Name, Encoding, Decoding, Comments โ I'm giving you the same tea, just in list form:
3dostrโ decoding only4xmโ decoding only โ 4X Technologies format, used in some games.8088flex TMVโ decoding onlyAAXโ decoding only โ Audible Enhanced Audio format, used in audiobooks.AAโ decoding only โ Audible Format 2, 3, and 4, used in audiobooks.ACT Voiceโ decoding only โ contains G.729 audioAdobe Filmstripโ encoding โ and decoding โAudio IFF (AIFF)โ encoding โ and decoding โAmerican Laser Games MMโ decoding only โ Multimedia format used in games like Mad Dog McCree.
okay so the actual format list starts here, alphabetical-ish, numbers first ๐ quick legend before we go: demux = ffmpeg can read it, mux = ffmpeg can write it. no cap, that's the whole table.
3GPP AMRโ demux โ ยท mux โAmazing Studio Packed Animation Fileโ mux โ only- the multimedia format used in the game Heart Of Darkness
Apple HTTP Live Streamingโ mux โ onlyArtworx Data Formatโ mux โ onlyInterplay ACMโ mux โ only- audio-only format, used in some Interplay games
ADPโ mux โ only- audio format used on the Nintendo Gamecube
AFCโ mux โ only- also an audio format used on the Nintendo Gamecube
ADS/SS2โ mux โ only- audio format used on the PS2
APNGโ demux โ ยท mux โASFโ demux โ ยท mux โ- that's Advanced / Active Streaming Format
ASTโ demux โ ยท mux โ- audio format used on the Nintendo Wii
AVIโ demux โ ยท mux โAviSynthโ mux โ onlyAVRโ mux โ only- audio format used on Mac
AVSโ mux โ only- multimedia format used by the Creature Shock game
Beam Software SIFFโ mux โ only- audio + video format used in some games by Beam Software
Bethesda Softworks VIDโ mux โ only- used in some games from Bethesda Softworks
Binary textโ mux โ onlyBinkโ mux โ only- multimedia format used by many games
Bink Audioโ mux โ only- audio-only multimedia format used by some games
Bitmap Brothers JVโ mux โ only- used in the Z and Z95 games
BRPโ mux โ only- Argonaut Games format
Brute Force & Ignoranceโ mux โ only- used in the game Flash Traffic: City of Angels
BFSTMโ mux โ only- audio format used on the Nintendo WiiU (based on BRSTM)
BRSTMโ mux โ only- audio format used on the Nintendo Wii
BW64โ mux โ only- Broadcast Wave 64bit
BWFโ demux โ ยท mux โcodec2 (raw)โ demux โ ยท mux โ- you must pass the
-modeformat option or it won't decode correctly ๐ซถ
- you must pass the
codec2 (.c2 files)โ demux โ ยท mux โ- these carry a header with version + mode info, so playback is way simpler
CRI ADXโ demux โ ยท mux โ- audio-only format used in console video games
CRI AIXโ mux โ onlyCRI HCAโ mux โ only- audio-only format used in console video games
Discworld II BMVโ mux โ onlyInterplay C93โ mux โ only- used in the game Cyberia from Interplay
Delphine Software International CINโ mux โ only- multimedia format used by Delphine Software games
Digital Speech Standard (DSS)โ mux โ onlyCD+Gโ mux โ only- video format used by CD+G karaoke disks ๐ค
Phantom Cineโ mux โ onlyCommodore CDXLโ mux โ only- Amiga CD video format
Core Audio Formatโ demux โ ยท mux โ- Apple Core Audio Format
CRC testing formatโ demux โ onlyCreative Voiceโ demux โ ยท mux โ- created for the Sound Blaster Pro
CRYO APCโ mux โ only- audio format used in some games by CRYO Interactive Entertainment
D-Cinema audioโ demux โ ยท mux โDeluxe Paint Animationโ mux โ onlyDCSTRโ mux โ onlyDFAโ mux โ only- this format is used in the Chronomaster game
DirectDraw Surfaceโ mux โ onlyDSD Stream File (DSF)โ mux โ onlyDV videoโ demux โ ยท mux โDXAโ mux โ only- used in the non-Windows version of the Feeble Files game, and in different game cutscenes repacked for use with ScummVM
Electronic Arts cdataโ mux โ onlyElectronic Arts Multimediaโ mux โ only- used in various EA games; files have extensions like WVE and UV2
Ensoniq Paris Audio Fileโ mux โ onlyFFM (FFserver live feed)โ demux โ ยท mux โFlash (SWF)โ demux โ ยท mux โFlash 9 (AVM2)โ demux โ ยท mux โ- only the embedded audio gets decoded, js
FLI/FLC/FLX animationโ mux โ only.fli/.flcfiles
Flash Video (FLV)โ demux โ ยท mux โ- Macromedia Flash video files
framecrc testing formatโ demux โ onlyFunCom ISSโ mux โ only- audio format used in various games from FunCom like The Longest Journey
G.723.1โ demux โ ยท mux โG.726โ mux โ only- both left- and right-justified
G.729 BITโ demux โ ยท mux โG.729 rawโ demux โ onlyGENHโ mux โ only- audio format for various games
GIF Animationโ demux โ ยท mux โGXFโ demux โ ยท mux โ- General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers
HNMโ mux โ only- only version 4 is supported, used in some games from Cryo Interactive
iCEDraw Fileโ mux โ onlyICOโ demux โ ยท mux โ- Microsoft Windows ICO
id Quake II CIN videoโ mux โ onlyid RoQโ demux โ ยท mux โ- used in Quake III, Jedi Knight 2 and other computer games
IEC61937 encapsulationโ demux โ ยท mux โIFFโ mux โ only- Interchange File Format
IFVโ mux โ only- a format used by some old CCTV DVRs
iLBCโ demux โ ยท mux โInterplay MVEโ mux โ only- format used in various Interplay computer games
Iterated Systems ClearVideoโ mux โ only- I-frames only
IV8โ mux โ only- a format generated by the IndigoVision 8000 video server
IVF (On2)โ demux โ ยท mux โ- a format used by
libvpx
- a format used by
Internet Video Recordingโ mux โ onlyIRCAMโ demux โ ยท mux โLAFโ mux โ only- Limitless Audio Format
LATMโ demux โ ยท mux โLMLM4โ mux โ only- used by Linux Media Labs MPEG-4 PCI boards
LOASโ mux โ only- contains LATM multiplexed AAC audio
LRCโ demux โ ยท mux โLVFโ mux โ onlyLXFโ mux โ only- VR native stream format, used by Leitch/Harris' video servers
Magic Lantern Video (MLV)โ mux โ onlyMatroskaโ demux โ ยท mux โMatroska audioโ demux โ onlyFFmpeg metadataโ demux โ ยท mux โ- metadata in text format
MAXIS XAโ mux โ only- used in Sim City 3000; file extension
.xa
- used in Sim City 3000; file extension
MCAโ mux โ only- used in some games from Capcom; file extension
.mca
- used in some games from Capcom; file extension
MD Studioโ mux โ onlyMetal Gear Solid: The Twin Snakesโ demux โ onlyMegalux Frameโ mux โ only- used by Megalux Ultimate Paint
MobiClip MODSโ mux โ onlyMobiClip MOFLEXโ mux โ onlyMobotix .mxgโ mux โ onlyMonkey's Audioโ mux โ onlyMotion Pixels MVIโ mux โ onlyMOV/QuickTime/MP4โ demux โ ยท mux โ- 3GP, 3GP2, PSP and iPod variants supported ๐
MP2โ demux โ ยท mux โMP3โ demux โ ยท mux โMPEG-1 Systemโ demux โ ยท mux โ- muxed audio and video, VCD format supported
MPEG-PS (program stream)โ demux โ ยท mux โ- also known as a
VOBfile; SVCD and DVD format supported
- also known as a
MPEG-TS (transport stream)โ demux โ ยท mux โ- also known as DVB Transport Stream
MPEG-4โ demux โ ยท mux โ- MPEG-4 is a variant of QuickTime
MSFโ mux โ only- audio format used on the PS3
Mirillis FIC videoโ mux โ only- no cursor rendering
MIDI Sample Dump Standardโ mux โ onlyMIME multipart JPEGโ demux โ onlyMSN TCP webcamโ mux โ only- used by MSN Messenger webcam streams
MTVโ mux โ onlyMusepackโ mux โ onlyMusepack SV8โ mux โ onlyMaterial eXchange Format (MXF)โ demux โ ยท mux โ- SMPTE 377M, used by D-Cinema and the broadcast industry
Material eXchange Format (MXF), D-10 Mappingโ demux โ ยท mux โ- SMPTE 386M, D-10/IMX Mapping
NC camera feedโ mux โ only- NC (AVIP NC4600) camera streams
NIST SPeech HEader REsourcesโ mux โ onlyComputerized Speech Lab NSPโ mux โ onlyNTT TwinVQ (VQF)โ mux โ only- Nippon Telegraph and Telephone Corporation TwinVQ
Nullsoft Streaming Videoโ mux โ onlyNuppelVideoโ mux โ onlyNUTโ demux โ ยท mux โ- NUT Open Container Format
Oggโ demux โ ยท mux โPlaystation Portable PMPโ mux โ onlyPortable Voice Formatโ mux โ onlyRK Audio (RKA)โ mux โ onlyTechnoTrend PVAโ mux โ only- used by TechnoTrend DVB PCI boards
and that's not even the end of the list bestie, we're still going ๐โจ
Quick key refresher before we keep going, bestie: in these rows a X under a column means that feature is supported for that format. Enc X = encoding works, Dec X = decoding works, and a โ is the blank cell (so, not supported). Now, onward ๐
QCPโ Enc โ ยท DecXraw ADTS (AAC)โ EncXยท DecXraw AC-3โ EncXยท DecXraw AMR-NBโ Enc โ ยท DecXraw AMR-WBโ Enc โ ยท DecXraw APACโ Enc โ ยท DecXraw APVโ EncXยท DecXraw aptXโ EncXยท DecXraw aptX HDโ EncXยท DecXraw Bonkโ Enc โ ยท DecXraw Chinese AVS videoโ EncXยท DecXraw DFPWMโ EncXยท DecXraw Diracโ EncXยท DecXraw DNxHDโ EncXยท DecXraw DTSโ EncXยท DecXraw DTS-HDโ Enc โ ยท DecXraw E-AC-3โ EncXยท DecXraw EVCโ EncXยท DecXraw FLACโ EncXยท DecXraw G.728โ Enc โ ยท DecXraw GSMโ Enc โ ยท DecXraw H.261โ EncXยท DecXraw H.263โ EncXยท DecXraw H.264โ EncXยท DecXraw HEVCโ EncXยท DecXraw Ingenient MJPEGโ Enc โ ยท DecXraw MJPEGโ EncXยท DecXraw MLPโ Enc โ ยท DecXraw MPEGโ Enc โ ยท DecXraw MPEG-1โ Enc โ ยท DecXraw MPEG-2โ Enc โ ยท DecXraw MPEG-4โ EncXยท DecXraw NULLโ EncXยท Dec โraw videoโ EncXยท DecXraw id RoQโ EncXยท Dec โraw OBUโ EncXยท DecXraw OSQโ Enc โ ยท DecXraw SBCโ EncXยท DecXraw Shortenโ Enc โ ยท DecXraw TAKโ Enc โ ยท DecXraw TrueHDโ EncXยท DecXraw VC-1โ EncXยท DecXraw PCM A-lawโ EncXยท DecXraw PCM mu-lawโ EncXยท DecXraw PCM Archimedes VIDCโ EncXยท DecXraw PCM signed 8 bitโ EncXยท DecXraw PCM signed 16 bit big-endianโ EncXยท DecXraw PCM signed 16 bit little-endianโ EncXยท DecXraw PCM signed 24 bit big-endianโ EncXยท DecXraw PCM signed 24 bit little-endianโ EncXยท DecXraw PCM signed 32 bit big-endianโ EncXยท DecXraw PCM signed 32 bit little-endianโ EncXยท DecXraw PCM signed 64 bit big-endianโ EncXยท DecXraw PCM signed 64 bit little-endianโ EncXยท DecXraw PCM unsigned 8 bitโ EncXยท DecXraw PCM unsigned 16 bit big-endianโ EncXยท DecXraw PCM unsigned 16 bit little-endianโ EncXยท DecXraw PCM unsigned 24 bit big-endianโ EncXยท DecXraw PCM unsigned 24 bit little-endianโ EncXยท DecXraw PCM unsigned 32 bit big-endianโ EncXยท DecXraw PCM unsigned 32 bit little-endianโ EncXยท DecXraw PCM 16.8 floating point little-endianโ Enc โ ยท DecXraw PCM 24.0 floating point little-endianโ Enc โ ยท DecXraw PCM floating-point 32 bit big-endianโ EncXยท DecXraw PCM floating-point 32 bit little-endianโ EncXยท DecXraw PCM floating-point 64 bit big-endianโ EncXยท DecXraw PCM floating-point 64 bit little-endianโ EncXยท DecXRDTโ Enc โ ยท DecXREDCODE R3Dโ Enc โ ยท DecX- File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio. ๐ฅ
RealMediaโ EncXยท DecXRedirectorโ Enc โ ยท DecXRedSparkโ Enc โ ยท DecXRenderware TeXture Dictionaryโ Enc โ ยท DecXResolume DXVโ EncXยท DecX- Encoding is only supported for the DXT1 (Normal Quality, No Alpha) texture format. โ ๏ธ
RF64โ Enc โ ยท DecXRL2โ Enc โ ยท DecX- Audio and video format used in some games by Entertainment Software Partners.
RPL/ARMovieโ Enc โ ยท DecXLego Mindstorms RSOโ EncXยท DecXRSDโ Enc โ ยท DecXRTMPโ EncXยท DecX- Output is performed by publishing stream to RTMP server
RTPโ EncXยท DecXRTSPโ EncXยท DecXSample Dump eXchangeโ Enc โ ยท DecXSAPโ EncXยท DecXSBGโ Enc โ ยท DecXSDNSโ Enc โ ยท DecXSDPโ Enc โ ยท DecXSERโ Enc โ ยท DecXDigital Pictures SGAโ Enc โ ยท DecXSega FILM/CPKโ EncXยท DecX- Used in many Sega Saturn console games. ๐ฎ
Silicon Graphics Movieโ Enc โ ยท DecXSierra SOLโ Enc โ ยท DecX- .sol files used in Sierra Online games.
Sierra VMDโ Enc โ ยท DecX- Used in Sierra CD-ROM games.
Smackerโ Enc โ ยท DecX- Multimedia format used by many games.
SMJPEGโ EncXยท DecX- Used in certain Loki game ports.
SMPTE 337M encapsulationโ Enc โ ยท DecXSmushโ Enc โ ยท DecX- Multimedia format used in some LucasArts games.
Sony OpenMG (OMA)โ EncXยท DecX- Audio format used in Sony Sonic Stage and Sony Vegas.
Sony PlayStation STRโ Enc โ ยท DecXSony Wave64 (W64)โ EncXยท DecXSoX native formatโ EncXยท DecXSUN AU formatโ EncXยท DecXSUP raw PGS subtitlesโ EncXยท DecXSVAGโ Enc โ ยท DecX- Audio format used in Konami PS2 games.
TDSCโ Enc โ ยท DecXText filesโ Enc โ ยท DecXTHPโ Enc โ ยท DecX- Used on the Nintendo GameCube.
Tiertex Limited SEQโ Enc โ ยท DecX- Tiertex .seq files used in the DOS CD-ROM version of the game Flashback.
True Audioโ EncXยท DecXVAGโ Enc โ ยท DecX- Audio format used in many Sony PS2 games.
VC-1 test bitstreamโ EncXยท DecXVidvox Hapโ EncXยท DecXVivoโ Enc โ ยท DecXVPKโ Enc โ ยท DecX- Audio format used in Sony PS games.
Marble WADYโ Enc โ ยท DecXWAVโ EncXยท DecXWaveform Archiverโ Enc โ ยท DecXWavPackโ EncXยท DecXWebMโ EncXยท DecXWindows Televison (WTV)โ EncXยท DecXWing Commander III movieโ Enc โ ยท DecX- Multimedia format used in Origin's Wing Commander III computer game.
Westwood Studios audioโ EncXยท DecX- Multimedia format used in Westwood Studios games.
Westwood Studios VQAโ Enc โ ยท DecX- Multimedia format used in Westwood Studios games.
Wideband Single-bit Data (WSD)โ Enc โ ยท DecXWVEโ Enc โ ยท DecXKonami XMDโ Enc โ ยท DecXXMVโ Enc โ ยท DecX- Microsoft video container used in Xbox games.
XVAGโ Enc โ ยท DecX- Audio format used on the PS3.
xWMAโ Enc โ ยท DecX- Microsoft audio container used by XAudio 2.
eXtended BINary text (XBIN)โ EncXยท DecXYUV4MPEG pipeโ EncXยท DecXPsygnosis YOPโ Enc โ ยท DecX
And that's the whole container/format list, babes ๐ โ X means that the feature in that column (encoding / decoding) is supported. Periodt.
๐ Image Formats ๐
FFmpeg can read and write images for each frame of a video sequence โ yes, every single frame, she's versatile ๐ . The following image formats are supported:
This table's got three columns, so read it like: Encoding ยท Decoding ยท the lil comment. AXmeans supported in that column,Emeans support comes through an external library.
.Y.U.Vโ EncXยท DecX- one raw file per component
Alias PIXโ EncXยท DecX- Alias/Wavefront PIX image format
animated GIFโ EncXยท DecXAPNGโ EncXยท DecX- Animated Portable Network Graphics
BMPโ EncXยท DecX- Microsoft BMP image
BRender PIXโ Enc โ ยท DecX- Argonaut BRender 3D engine image format.
CRIโ Enc โ ยท DecX- Cintel RAW
DPXโ EncXยท DecX- Digital Picture Exchange
EXRโ Enc โ ยท DecX- OpenEXR
FITSโ EncXยท DecX- Flexible Image Transport System
HDRโ EncXยท DecX- Radiance HDR RGBE Image format
IMGโ Enc โ ยท DecX- GEM Raster image
JPEGโ EncXยท DecX- Progressive JPEG is not supported. โ ๏ธ note that, bestie
JPEG 2000โ EncXยท DecXJPEG-LSโ EncXยท DecXJPEG-XSโ EncEยท DecE- Supported through external library
libsvtjpegxs
- Supported through external library
LJPEGโ EncXยท Dec โ- Lossless JPEG
Media 100โ Enc โ ยท DecXMSPโ Enc โ ยท DecX- Microsoft Paint image
PAMโ EncXยท DecX- PAM is a PNM extension with alpha support.
PBMโ EncXยท DecX- Portable BitMap image
PCDโ Enc โ ยท DecX- PhotoCD
PCXโ EncXยท DecX- PC Paintbrush
PFMโ EncXยท DecX- Portable FloatMap image
PGMโ EncXยท DecX- Portable GrayMap image
PGMYUVโ EncXยท DecX- PGM with U and V components in YUV 4:2:0
PGXโ Enc โ ยท DecX- PGX file decoder
PHMโ EncXยท DecX- Portable HalfFloatMap image
PICโ Enc โ ยท DecX- Pictor/PC Paint
PNGโ EncXยท DecX- Portable Network Graphics image
PPMโ EncXยท DecX- Portable PixelMap image
PSDโ Enc โ ยท DecX- Photoshop
PTXโ Enc โ ยท DecX- V.Flash PTX format
QOIโ EncXยท DecX- Quite OK Image format
SGIโ EncXยท DecX- SGI RGB image format
Sun Rasterfileโ EncXยท DecX- Sun RAS image format
TIFFโ EncXยท DecX- YUV, JPEG and some extension is not supported yet.
Truevision Targaโ EncXยท DecX- Targa (.TGA) image format
VBNโ EncXยท DecX- Vizrt Binary Image format
WBMPโ EncXยท DecX- Wireless Application Protocol Bitmap image format
WebPโ EncEยท DecX- WebP image format, encoding supported through external library
libwebp
- WebP image format, encoding supported through external library
XBMโ EncXยท DecX- X BitMap image format
XFaceโ EncXยท DecX- X-Face image format
XPMโ Enc โ ยท DecX- X PixMap image format
XWDโ EncXยท DecX- X Window Dump image format
Two legend girlies for this one ๐ซถ: X means that the feature in that column (encoding / decoding) is supported, and E means that support is provided through an external library.
๐ Video Codecs ๐
Same deal, three-column energy: Name ยท Encoding ยท Decoding ยท Comments.
4X Movieโ Enc โ ยท DecX- Used in certain computer games.
- 8088flex TMV โ decode
Xonly, play it but don't make it ๐ฌ - A64 multicolor โ encode
X; creates video suitable to be played on a commodore 64 (multicolor mode). literally a C64 maker bestie, iconic ๐ - Amazing Studio PAF Video โ decode
X - American Laser Games MM โ decode
X; used in games like Mad Dog McCree ๐ฏ - Amuse Graphics Movie โ decode
X - AMV Video โ encode
X, decodeX; used in Chinese MP3 players ๐ง - ANSI/ASCII art โ decode
X - Apple Intermediate Codec โ decode
X - Apple MJPEG-B โ decode
X - Apple Pixlet โ decode
X - Apple ProRes โ encode
X, decodeX; fourcc:apch,apcn,apcs,apco,ap4h,ap4x๐ - Apple QuickDraw โ decode
X; fourcc:qdrw - APV โ decode
X - Argonaut Video โ decode
X; used in some Argonaut games - Asus v1 โ encode
X, decodeX; fourcc:ASV1 - Asus v2 โ encode
X, decodeX; fourcc:ASV2 - ATI VCR1 โ decode
X; fourcc:VCR1 - ATI VCR2 โ decode
X; fourcc:VCR2 - Auravision Aura โ decode
X - Auravision Aura 2 โ decode
X - Autodesk Animator Flic video โ decode
X - Autodesk RLE โ decode
X; fourcc:AASC - AV1 โ encode
E, decodeE; supported through external librarieslibaom,libdav1d,librav1eandlibsvtav1โจ - Avid 1:1 10-bit RGB Packer โ encode
X, decodeX; fourcc:AVrp - AVS (Audio Video Standard) video โ decode
X; video encoding used by the Creature Shock game - AVS2-P2/IEEE1857.4 โ encode
E, decodeE; supported through external librarieslibxavs2andlibdavs2 - AVS3-P2/IEEE1857.10 โ decode
E; supported through external librarylibuavs3d - AYUV โ encode
X, decodeX; Microsoft uncompressed packed 4:4:4:4 ๐ - Beam Software VB โ decode
X - Bethesda VID video โ decode
X; used in some games from Bethesda Softworks - Bink Video โ decode
X - BitJazz SheerVideo โ decode
X - Bitmap Brothers JV video โ decode
X - y41p Brooktree uncompressed 4:1:1 12-bit โ encode
X, decodeX - Brooktree ProSumer Video โ decode
X; fourcc:BT20 - Brute Force & Ignorance โ decode
X; used in the game Flash Traffic: City of Angels - C93 video โ decode
X; codec used in Cyberia game - CamStudio โ decode
X; fourcc:CSCD - CD+G โ decode
X; video codec for CD+G karaoke disks ๐ค - CDXL โ decode
X; Amiga CD video codec - Chinese AVS video โ encode
E, decodeX; AVS1-P2, JiZhun profile, encoding through external librarylibxavs - Delphine Software International CIN video โ decode
X; codec used in Delphine Software International games - Discworld II BMV Video โ decode
X - CineForm HD โ encode
X, decodeX - Canopus HQ โ decode
X - Canopus HQA โ decode
X - Canopus HQX โ decode
X - Canopus Lossless Codec โ decode
X - CDToons โ decode
X; codec used in various Broderbund games - Cinepak โ decode
X - Cirrus Logic AccuPak โ encode
X, decodeX; fourcc:CLJR - CPiA Video Format โ decode
X - Creative YUV (CYUV) โ decode
X - DFA โ decode
X; codec used in Chronomaster game - Dirac โ encode
E, decodeX; supported through the nativevc2(Dirac Pro) encoder - Deluxe Paint Animation โ decode
X - DNxHD โ encode
X, decodeX; aka SMPTE VC3 - Duck TrueMotion 1.0 โ decode
X; fourcc:DUCK๐ฆ - Duck TrueMotion 2.0 โ decode
X; fourcc:TM20 - Duck TrueMotion 2.0 RT โ decode
X; fourcc:TR20 - DV (Digital Video) โ encode
X, decodeX - Dxtory capture format โ decode
X - Feeble Files/ScummVM DXA โ decode
X; codec originally used in Feeble Files game - Electronic Arts CMV video โ decode
X; used in NHL 95 game ๐ - Electronic Arts Madcow video โ decode
X - Electronic Arts TGV video โ decode
X - Electronic Arts TGQ video โ decode
X - Electronic Arts TQI video โ decode
X - Escape 124 โ decode
X - Escape 130 โ decode
X - EVC / MPEG-5 Part 1 โ encode
E, decodeE; encoding and decoding supported through external librarieslibxeveandlibxevd๐ฅ - FFmpeg video codec #1 โ encode
X, decodeX; lossless codec (fourcc:FFV1) โ the homegrown icon, we stan ๐ - Flash Screen Video v1 โ encode
X, decodeX; fourcc:FSV1 - Flash Screen Video v2 โ encode
X, decodeX - Flash Video (FLV) โ encode
X, decodeX; Sorenson H.263 used in Flash - FM Screen Capture Codec โ decode
X - Forward Uncompressed โ decode
X - Fraps โ decode
X - Go2Meeting โ decode
X; fourcc:G2M2, G2M3 - Go2Webinar โ decode
X; fourcc:G2M4 - Gremlin Digital Video โ decode
X - H.261 โ encode
X, decodeX - H.263 / H.263-1996 โ encode
X, decodeX - H.263+ / H.263-1998 / H.263 version 2 โ encode
X, decodeX - H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 โ encode
E, decodeX; encoding supported through external librarylibx264andOpenH264๐ - HEVC โ encode
X, decodeX; encoding supported through external librarylibx265andlibkvazaar - HNM version 4 โ decode
X - HuffYUV โ encode
X, decodeX - HuffYUV FFmpeg variant โ encode
X, decodeX - IBM Ultimotion โ decode
X; fourcc:ULTI - id Cinematic video โ decode
X; used in Quake II - id RoQ video โ encode
X, decodeX; used in Quake III, Jedi Knight 2, other computer games ๐ฎ - IFF ILBM โ decode
X; IFF interleaved bitmap - IFF ByteRun1 โ decode
X; IFF run length encoded bitmap - Infinity IMM4 โ decode
X - Intel H.263 โ decode
X - Intel Indeo 2 โ decode
X - Intel Indeo 3 โ decode
X - Intel Indeo 4 โ decode
X - Intel Indeo 5 โ decode
X - Interplay C93 โ decode
X; used in the game Cyberia from Interplay - Interplay MVE video โ decode
X; used in Interplay.MVEfiles - J2K โ encode
X, decodeX - Karl Morton's video codec โ decode
X; codec used in Worms games ๐ชฑ - Kega Game Video (KGV1) โ decode
X; Kega emulator screen capture codec - Lagarith โ decode
X - LCEVC / MPEG-5 LCEVC / MPEG-5 Part 2 โ decode
E; decoding supported through external libraryliblcevc-dec - LCL (LossLess Codec Library) MSZH โ decode
X - LCL (LossLess Codec Library) ZLIB โ encode
E, decodeE - LEAD MCMP โ decode
X - LOCO โ decode
X - LucasArts SANM/Smush โ decode
X; used in LucasArts games / SMUSH animations - lossless MJPEG โ encode
X, decodeX - MagicYUV Video โ encode
X, decodeX - Mandsoft Screen Capture Codec โ decode
X - Microsoft ATC Screen โ decode
X; also known as Microsoft Screen 3 - Microsoft Expression Encoder Screen โ decode
X; also known as Microsoft Titanium Screen 2 - Microsoft RLE โ encode
X, decodeX - Microsoft Screen 1 โ decode
X; also known as Windows Media Video V7 Screen - Microsoft Screen 2 โ decode
X; also known as Windows Media Video V9 Screen - Microsoft Video 1 โ decode
X - Mimic โ decode
X; used in MSN Messenger Webcam streams ๐น - Miro VideoXL โ decode
X; fourcc:VIXL - MJPEG (Motion JPEG) โ encode
X, decodeX - Mobotix MxPEG video โ decode
X - Motion Pixels video โ decode
X - MPEG-1 video โ encode
X, decodeX - MPEG-2 video โ encode
X, decodeX - MPEG-4 part 2 โ encode
X, decodeX;libxvidcorecan be used alternatively for encoding - MPEG-4 part 2 Microsoft variant version 1 โ decode
X - MPEG-4 part 2 Microsoft variant version 2 โ encode
X, decodeX - MPEG-4 part 2 Microsoft variant version 3 โ encode
X, decodeX - Newtek SpeedHQ โ encode
X, decodeX - Nintendo Gamecube THP video โ decode
X๐ฎ - NotchLC โ decode
X - NuppelVideo/RTjpeg โ decode
X; video encoding used in NuppelVideo files - On2 VP3 โ decode
X; still experimental โ ๏ธ - On2 VP4 โ decode
X; fourcc:VP40 - On2 VP5 โ decode
X; fourcc:VP50 - On2 VP6 โ decode
X; fourcc:VP60,VP61,VP62 - On2 VP7 โ decode
X; fourcc:VP70,VP71 - VP8 โ encode
E, decodeX; fourcc:VP80, encoding supported through external librarylibvpx - VP9 โ encode
E, decodeX; encoding supported through external librarylibvpx - Pinnacle TARGA CineWave YUV16 โ decode
X; fourcc:Y216 - Q-team QPEG โ decode
X; fourccs:QPEG,Q1.0,Q1.1 - QuickTime 8BPS video โ decode
X - QuickTime Animation (RLE) video โ encode
X, decodeX; fourcc:'rle ' - QuickTime Graphics (SMC) โ encode
X, decodeX; fourcc:'smc ' - QuickTime video (RPZA) โ encode
X, decodeX; fourcc:rpza - R10K AJA Kona 10-bit RGB Codec โ encode
X, decodeX - R210 Quicktime Uncompressed RGB 10-bit โ encode
X, decodeX - Raw Video โ encode
X, decodeX๐ง - RealVideo 1.0 โ encode
X, decodeX - RealVideo 2.0 โ encode
X, decodeX - RealVideo 3.0 โ decode
X; still far from ideal ๐ญ - RealVideo 4.0 โ decode
X - RealVideo 6.0 โ decode
X - Renderware TXD (TeXture Dictionary) โ decode
X; texture dictionaries used by the Renderware Engine - RivaTuner Video โ decode
X; fourcc:'RTV1' - RL2 video โ decode
X; used in some games by Entertainment Software Partners
...and we're still rolling through the video codec table, bestie โ hydrate, stretch, we're nearly at the bottom of this alphabet ๐
- ScreenPressor โ decode only.
- Screenpresso โ decode only.
- Screen Recorder Gold Codec โ decode only.
- Sierra VMD video โ decode only. Used in Sierra VMD files.
- Silicon Graphics Motion Video Compressor 1 (MVC1) โ decode only.
- Silicon Graphics Motion Video Compressor 2 (MVC2) โ decode only.
- Silicon Graphics RLE 8-bit video โ decode only.
- Smacker video โ decode only. Video encoding used in Smacker.
- SMPTE VC-1 โ decode only.
- Snow โ encode + decode. experimental wavelet codec (
fourcc: SNOW) - Sony PlayStation MDEC (Motion DECoder) โ decode only.
- Sorenson Vector Quantizer 1 โ encode + decode.
fourcc: SVQ1 - Sorenson Vector Quantizer 3 โ decode only.
fourcc: SVQ3 - Sunplus JPEG (SP5X) โ decode only.
fourcc: SP5X - TechSmith Screen Capture Codec โ decode only.
fourcc: TSCC - TechSmith Screen Capture Codec 2 โ decode only.
fourcc: TSC2 - Theora โ encode
E, decodeX. encoding supported through external librarylibtheora - Tiertex Limited SEQ video โ decode only. Codec used in DOS CD-ROM FlashBack game.
- Ut Video โ encode + decode.
- v210 QuickTime uncompressed 4:2:2 10-bit โ encode + decode.
- v308 QuickTime uncompressed 4:4:4 โ encode + decode.
- v408 QuickTime uncompressed 4:4:4:4 โ encode + decode.
- v410 QuickTime uncompressed 4:4:4 10-bit โ encode + decode.
- VBLE Lossless Codec โ decode only.
- vMix Video โ decode only.
fourcc: 'VMX1' - VMware Screen Codec / VMware Video โ decode only. Codec used in videos captured by VMware.
- Westwood Studios VQA (Vector Quantized Animation) video โ decode only.
- Windows Media Image โ decode only.
- Windows Media Video 7 โ encode + decode.
- Windows Media Video 8 โ encode + decode.
- Windows Media Video 9 โ decode only. not completely working ๐ญ
- Wing Commander III / Xan โ decode only. Used in Wing Commander III
.MVEfiles. - Wing Commander IV / Xan โ decode only. Used in Wing Commander IV.
- Winnov WNV1 โ decode only.
- WMV7 โ encode + decode.
- YAMAHA SMAF โ encode + decode.
- Psygnosis YOP Video โ decode only.
- yuv4 โ encode + decode.
libquicktimeuncompressed packed 4:2:0 - ZeroCodec Lossless Video โ decode only.
- ZLIB โ encode + decode. part of LCL, encoder experimental โ ๏ธ
- Zip Motion Blocks Video โ encode + decode. Encoder works only in PAL8.
Legend time, because the letters matter:
"X"means that the feature in that column (encoding / decoding) is supported."E"means that support is provided through an external library.
๐ง Audio Codecs
Same deal as above, but for your ears. The columns are Name : Encoding @tab Decoding @tab Comments โ slay.
- 8SVX exponential โ decode only.
- 8SVX fibonacci โ decode only.
- AAC โ encode
EX, decodeX. encoding supported through internal encoder and external librarylibfdk-aac - AAC+ โ encode
E, decodeIX. encoding supported through external librarylibfdk-aac - AC-3 โ encode
IX, decodeIX. - ACELP.KELVIN โ decode only.
- ADPCM 4X Movie โ decode only.
- ADPCM Yamaha AICA โ decode only.
- ADPCM AmuseGraphics Movie โ decode only.
- ADPCM Argonaut Games โ encode + decode.
- ADPCM CDROM XA โ decode only.
- ADPCM Creative Technology โ decode only.
16 -> 4,8 -> 4,8 -> 3,8 -> 2 - ADPCM Electronic Arts โ decode only. Used in various EA titles.
- ADPCM Electronic Arts Maxis CDROM XS โ decode only. Used in Sim City 3000.
- ADPCM Electronic Arts R1 โ decode only.
- ADPCM Electronic Arts R2 โ decode only.
- ADPCM Electronic Arts R3 โ decode only.
- ADPCM Electronic Arts XAS โ decode only.
- ADPCM G.722 โ encode + decode.
- ADPCM G.726 โ encode + decode.
- ADPCM IMA Acorn Replay โ decode only.
- ADPCM IMA AMV โ encode + decode. Used in AMV files
- ADPCM IMA Cunning Developments โ decode only.
- ADPCM IMA Electronic Arts EACS โ decode only.
- ADPCM IMA Electronic Arts SEAD โ decode only.
- ADPCM IMA Funcom โ decode only.
- ADPCM IMA High Voltage Software ALP โ encode + decode.
- ADPCM IMA Mobiclip MOFLEX โ decode only.
- ADPCM IMA QuickTime โ encode + decode.
- ADPCM IMA Simon & Schuster Interactive โ encode + decode.
- ADPCM IMA Ubisoft APM โ encode + decode.
- ADPCM IMA Loki SDL MJPEG โ decode only.
- ADPCM IMA WAV โ encode + decode.
- ADPCM IMA Westwood โ decode only.
- ADPCM ISS IMA โ decode only. Used in FunCom games.
- ADPCM IMA Dialogic โ decode only.
- ADPCM IMA Duck DK3 โ decode only. Used in some Sega Saturn console games.
- ADPCM IMA Duck DK4 โ decode only. Used in some Sega Saturn console games.
- ADPCM IMA Radical โ decode only.
- ADPCM IMA Xbox โ decode only.
- ADPCM Microsoft โ encode + decode.
- ADPCM MS IMA โ encode + decode.
- ADPCM Nintendo Gamecube AFC โ decode only.
- ADPCM Nintendo Gamecube DTK โ decode only.
- ADPCM Nintendo THP โ decode only.
- ADPCM Playstation โ decode only.
- ADPCM QT IMA โ encode + decode.
- ADPCM Sanyo โ decode only.
- ADPCM SEGA CRI ADX โ encode + decode. Used in Sega Dreamcast games.
- ADPCM Shockwave Flash โ encode + decode.
- ADPCM Sound Blaster Pro 2-bit โ decode only.
- ADPCM Sound Blaster Pro 2.6-bit โ decode only.
- ADPCM Sound Blaster Pro 4-bit โ decode only.
- ADPCM VIMA โ decode only. Used in LucasArts SMUSH animations.
- ADPCM Konami XMD โ decode only.
- ADPCM Westwood Studios IMA โ encode + decode. Used in Westwood Studios games like Command and Conquer.
- ADPCM Yamaha โ encode + decode.
- ADPCM Zork โ decode only.
- AMR-NB โ encode
E, decodeX. encoding supported through external librarylibopencore-amrnb - AMR-WB โ encode
E, decodeX. encoding supported through external librarylibvo-amrwbenc - Amazing Studio PAF Audio โ decode only.
- Apple lossless audio โ encode + decode. QuickTime fourcc
'alac' - aptX โ encode + decode. Used in Bluetooth A2DP
- aptX HD โ encode + decode. Used in Bluetooth A2DP
- ATRAC1 โ decode only.
- ATRAC3 โ decode only.
- ATRAC3+ โ decode only.
- ATRAC9 โ decode only.
- Bink Audio โ decode only. Used in Bink and Smacker files in many games.
- Bonk audio โ decode only.
- CELT โ decode
E. decoding supported through external librarylibcelt - codec2 โ encode
E, decodeE. en/decoding supported through external librarylibcodec2 - CRI HCA โ decode only.
- Delphine Software International CIN audio โ decode only. Codec used in Delphine Software International games.
- DFPWM โ encode + decode.
- Digital Speech Standard - Standard Play mode (DSS SP) โ decode only.
- Discworld II BMV Audio โ decode only.
- COOK โ decode only. All versions except 5.1 are supported. ๐
- DCA (DTS Coherent Acoustics) โ encode + decode. supported extensions:
XCh,XXCH,X96,XBR,XLL,LBR(partially) - Dolby E โ decode only.
- DPCM Cuberoot-Delta-Exact โ decode only. Used in few games.
- DPCM Gremlin โ decode only.
- DPCM id RoQ โ encode + decode. Used in Quake III, Jedi Knight 2 and other computer games.
- DPCM Marble WADY โ decode only.
- DPCM Interplay โ decode only. Used in various Interplay computer games.
- DPCM Squareroot-Delta-Exact โ decode only. Used in various games.
- DPCM Sierra Online โ decode only. Used in Sierra Online game audio files.
- DPCM Sol โ decode only.
- DPCM Xan โ decode only. Used in Origin's Wing Commander IV AVI files.
- DPCM Xilam DERF โ decode only.
- DSD (Direct Stream Digital), least significant bit first โ decode only.
- DSD (Direct Stream Digital), most significant bit first โ decode only.
- DSD (Direct Stream Digital), least significant bit first, planar โ decode only.
- DSD (Direct Stream Digital), most significant bit first, planar โ decode only.
- DSP Group TrueSpeech โ decode only.
- DST (Direct Stream Transfer) โ decode only.
- DV audio โ decode only.
- Enhanced AC-3 โ encode + decode.
- EVRC (Enhanced Variable Rate Codec) โ decode only.
- FLAC (Free Lossless Audio Codec) โ encode
X, decodeIX. - FTR Voice โ decode only.
- G.723.1 โ encode + decode.
- G.728 โ decode only.
- G.729 โ decode only.
- GSM โ encode
E, decodeX. encoding supported through external librarylibgsm - GSM Microsoft variant โ encode
E, decodeX. encoding supported through external librarylibgsm - IAC (Indeo Audio Coder) โ decode only.
- iLBC (Internet Low Bitrate Codec) โ encode
E, decodeEX. encoding and decoding supported through external librarylibilbc - IMC (Intel Music Coder) โ decode only.
- Interplay ACM โ decode only.
- LC3 โ encode
E, decodeE. supported through external libraryliblc3 - MACE (Macintosh Audio Compression/Expansion) 6:1 โ decode only.
- Marian's A-pac audio โ decode only.
- MI-SC4 (Micronas SC-4 Audio) โ decode only.
- MLP (Meridian Lossless Packing) โ encode + decode. Used in DVD-Audio discs.
- Monkey's Audio โ decode only.
- MP1 (MPEG audio layer 1) โ decode
IX. - MP2 (MPEG audio layer 2) โ encode
IX, decodeIX. encoding supported also through external library TwoLAME - MP3 (MPEG audio layer 3) โ encode
E, decodeIX. encoding supported through external library LAME, ADU MP3 and MP3onMP4 also supported - MPEG-4 Audio Lossless Coding (ALS) โ decode only.
- MPEG-H 3D Audio โ decode
E. decoding supported through external librarylibmpeghdec
...and we're picking right back up mid-codec-list, no biggie ๐ the audio codec tea continues:
MobiClip FastAudioโ decode onlyMusepack SV7โ decode onlyMusepack SV8โ decode onlyNellymoser Asaoโ encode โ + decode โOn2 AVC (Audio for Video Codec)โ decode onlyOpusโ encode isE, decode is โ (and bestie, thatEmeans encoding is supported through the external librarylibopus๐ซถ)OSQ (Original Sound Quality)โ decode onlyPCM A-lawโ encode โ + decode โPCM mu-lawโ encode โ + decode โPCM Archimedes VIDCโ encode โ + decode โPCM signed 8-bit planarโ encode โ + decode โPCM signed 16-bit big-endian planarโ encode โ + decode โPCM signed 16-bit little-endian planarโ encode โ + decode โPCM signed 24-bit little-endian planarโ encode โ + decode โPCM signed 32-bit little-endian planarโ encode โ + decode โPCM 32-bit floating point big-endianโ encode โ + decode โPCM 32-bit floating point little-endianโ encode โ + decode โPCM 64-bit floating point big-endianโ encode โ + decode โPCM 64-bit floating point little-endianโ encode โ + decode โPCM D-Cinema audio signed 24-bitโ encode โ + decode โPCM signed 8-bitโ encode โ + decode โPCM signed 16-bit big-endianโ encode โ + decode โPCM signed 16-bit little-endianโ encode โ + decode โPCM signed 24-bit big-endianโ encode โ + decode โPCM signed 24-bit little-endianโ encode โ + decode โPCM signed 32-bit big-endianโ encode โ + decode โPCM signed 32-bit little-endianโ encode โ + decode โPCM signed 16/20/24-bit big-endian in MPEG-TSโ decode onlyPCM unsigned 8-bitโ encode โ + decode โPCM unsigned 16-bit big-endianโ encode โ + decode โPCM unsigned 16-bit little-endianโ encode โ + decode โPCM unsigned 24-bit big-endianโ encode โ + decode โPCM unsigned 24-bit little-endianโ encode โ + decode โPCM unsigned 32-bit big-endianโ encode โ + decode โPCM unsigned 32-bit little-endianโ encode โ + decode โPCM SGAโ decode onlyQCELP / PureVoiceโ decode onlyQDesign Music Codec 1โ decode onlyQDesign Music Codec 2โ decode only ๐ญ and fr fr, there are still some distortions.RealAudio 1.0 (14.4K)โ encode โ + decode โ (the Real 14400 bit/s codec, iconic)RealAudio 2.0 (28.8K)โ decode only (Real 28800 bit/s codec)RealAudio 3.0 (dnet)โ encodeIX+ decode โ โ the Real low bitrate AC-3 codec โจRealAudio Losslessโ decode onlyRealAudio SIPR / ACELP.NETโ decode onlyRK Audio (RKA)โ decode onlySBC (low-complexity subband codec)โ encode โ + decode โ โ used in Bluetooth A2DP ๐งShortenโ decode onlySierra VMD audioโ decode only โ used in Sierra VMD files ๐ซถSmacker audioโ decode onlySMPTE 302M AES3 audioโ encode โ + decode โSonicโ encode โ + decode โ โ experimental codec bestie, noted ๐Sonic losslessโ encode โ + decode โ โ also experimental codecSpeexโ encodeE+ decodeEXโ supported through the external librarylibspeex๐TAK (Tom's lossless Audio Kompressor)โ decode onlyTrue Audio (TTA)โ encode โ + decode โTrueHDโ encode โ + decode โ โ used in HD-DVD and Blu-Ray discs ๐TwinVQ (VQF flavor)โ decode onlyVIMAโ decode only โ used in LucasArts SMUSH animations ๐ฎViewQuest VQCโ decode onlyVorbisโ encodeE+ decode โ โ ngl a native but very primitive encoder exists ๐ฌVoxware MetaSoundโ decode onlyWaveform Archiverโ decode onlyWavPackโ encode โ + decode โWestwood Audio (SND1)โ decode onlyWindows Media Audio 1โ encode โ + decode โWindows Media Audio 2โ encode โ + decode โWindows Media Audio Losslessโ decode onlyWindows Media Audio Proโ decode onlyWindows Media Audio Voiceโ decode onlyXbox Media Audio 1โ decode onlyXbox Media Audio 2โ decode only
Quick legend check so nobody's confused ๐
Xmeans that the feature in that column (encoding / decoding) is supported.Emeans that support is provided through an external library.Imeans that an integer-only version is available, too (which ensures high performance on systems without hardware floating point support โ lowkey important on tiny boxes ๐ง).
๐ Subtitle Formats ๐
Columns are muxing, demuxing, encoding, decoding, in that order bestie:
3GPP Timed Textโ encoding โ + decoding โAQTitleโ demuxing โ + decoding โDVBโ muxing โ + demuxing โ + encoding โ + decoding โ (full sweep, ate)DVB teletextโ demuxing โ + decodingEDVDโ muxing โ + demuxing โ + encoding โ + decoding โJACOsubโ muxing โ + demuxing โ + decoding โMicroDVDโ muxing โ + demuxing โ + decoding โMPL2โ demuxing โ + decoding โMPsub (MPlayer)โ demuxing โ + decoding โPGSโ decoding onlyPJS (Phoenix)โ demuxing โ + decoding โRealTextโ demuxing โ + decoding โSAMIโ demuxing โ + decoding โSpruce format (STL)โ demuxing โ + decoding โSSA/ASSโ muxing โ + demuxing โ + encoding โ + decoding โSubRip (SRT)โ muxing โ + demuxing โ + encoding โ + decoding โSubViewer v1โ demuxing โ + decoding โSubViewerโ demuxing โ + decoding โTED Talks captionsโ demuxing โ + decoding โTTMLโ muxing โ + encoding โ (demuxing and decoding left blank, that's just how it is ๐ )VobSub (IDX+SUB)โ demuxing โ + decoding โVPlayerโ demuxing โ + decoding โWebVTTโ muxing โ + demuxing โ + encoding โ + decoding โXSUBโ encoding โ + decoding โ
Legend time ๐ธ
Xmeans that the feature is supported.Emeans that support is provided through an external library.
๐ Network Protocols ๐
AMQPโE(external library, iykyk)fileโ โFTPโ โGopherโ โGophersโ โHLSโ โHTTPโ โHTTPSโ โIcecastโ โMMSHโ โMMSTโ โpipeโ โPro-MPEG FECโ โRTMPโ โRTMPEโ โRTMPSโ โRTMPTโ โRTMPTEโ โRTMPTSโ โRTPโ โSAMBAโESCTPโ โSFTPโETCPโ โTLSโ โUDPโ โZMQโE
Legend ๐ฆ
Xmeans that the protocol is supported.Emeans that support is provided through an external library.
โจ Input/Output Devices โจ
ALSAโ input โ + output โBKTRโ input โ (no output, she's input-only)cacaโ output โDV1394โ input โLavfi virtual deviceโ input โLinux framebufferโ input โ + output โJACKโ input โLIBCDIOโ input โLIBDC1394โ input โOpenALโ input โOpenGLโ output โOSSโ input โ + output โPulseAudioโ input โ + output โSDLโ output โVideo4Linux2โ input โ + output โVfW captureโ input โX11 grabbingโ input โWin32 grabbingโ input โ
Legend ๐
Xmeans that input/output is supported.
โญ Timecode โญ
Read then write, both slaying:
AVIโ read โ + write โDVโ read โ + write โGXFโ read โ + write โMOVโ read โ + write โMPEG1/2โ read โ + write โMXFโ read โ + write โ
๐ SEE ALSO ๐
Go read these next bestie, they're all canon:
ffmpeg(1), ffplay(1), ffprobe(1), ffmpeg-utils(1), ffmpeg-scaler(1), ffmpeg-resampler(1), ffmpeg-codecs(1), ffmpeg-bitstream-filters(1), ffmpeg-formats(1), ffmpeg-devices(1), ffmpeg-protocols(1), ffmpeg-filters(1)
๐ AUTHORS ๐
The FFmpeg developers. That's the whole credit line, and honestly? Respect ๐ซถ
For details about the authorship, see the Git history of the project (<https://git.ffmpeg.org/ffmpeg>), e.g. by typing the command git log in the FFmpeg source directory, or browsing the online repository at <https://git.ffmpeg.org/ffmpeg>. Go look, it's giving archaeology but make it code ๐ง
Maintainers for the specific components are listed in the file MAINTAINERS in the source code tree โ check there if you wanna know who to thank for your fave filter โจ
And that's a wrap on FFMPEG-ALL(1) ๐ฌโจ the whole manual, every last codec, subtitle format, protocol and device, all accounted for. Signing off with the page's own little footer energy โ source/version and date, exactly as the page stamps it, no cap ๐
periodt.
๐ฆ where this page comes from
- alpine 3.24: ffmpeg-doc 8.1.3-r0 ยท GPL-2.0-or-later AND LGPL-2.1-or-later
- nixos 26.05: ffmpeg 8.1.3
- nixos 26.05: ffmpeg-headless 8.1.3
- ๐ girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms