SPHINX_FE(1)

💖 SPHINX_FE 💖 (that's sphinx_fe, section 1 of the General Commands Manual, bestie)

✨ NAME ✨

sphinx_fe — convert audio files to acoustic feature files 🎧✨

🌸 SYNOPSIS 🌸

sphinx_fe [ options ]...

🦋 DESCRIPTION 🦋

Okay so picture this: you've got audio files. This little icon right here takes those audio files — and they can be in Microsoft WAV, NIST Sphere, or raw format, she's not picky 💅 — and turns them into acoustic feature files, which is what you feed into batch-mode speech recognition. Slay.

And lowkey? The resulting files are also useful for various other things. Versatile queen. 👑

A list of options follows, and bestie there are so many, but we're going through every single one, no skipping, periodt.

🎀 THE OPTIONS (all of them, fr fr) 🎀

• -alpha — Preemphasis parameter
• -argfile — file (e.g. feat.params from an acoustic model) to read parameters from. This will override anything set in other command line arguments. 👀 yeah, she overrides everything else, so watch it
• -blocksize — Number of samples to read at a time.
• -build_outdirs — Create missing subdirectories in output directory
• -c — file for batch processing
• -cep2spec — Input is cepstral files, output is log spectral files
• -di — directory, input file names are relative to this, if defined
• -dither — Add 1/2-bit noise
• -do — directory, output files are relative to this
• -doublebw — Use double bandwidth filters (same center freq)
• -ei — extension to be applied to all input files
• -eo — extension to be applied to all output files
• -example — Shows example of how to use the tool
• -frate — Frame rate
• -help — Shows the usage of the tool
• -i — audio input file
• -input_endian — Endianness of input data, big or little, ignored if NIST or MS Wav
• -lifter — Length of sin-curve for liftering, or 0 for no liftering.
• -logspec — Write out logspectral files instead of cepstra
• -lowerf — Lower edge of filters
• -mach_endian — Endianness of machine, big or little
• -mswav — Defines input format as Microsoft Wav (RIFF)
• -ncep — Number of cep coefficients
• -nchans — Number of channels of data (interlaced samples assumed)
• -nfft — Size of FFT
• -nfilt — Number of filter banks
• -nist — Defines input format as NIST sphere
• -npart — Number of parts to run in (supersedes -nskip and -runlen if non-zero)
• -nskip — If a control file was specified, the number of utterances to skip at the head of the file
• -o — cepstral output file
• -ofmt — Format of output files - one of sphinx, htk, text.
• -part — Index of the part to run (supersedes -nskip and -runlen if non-zero)
• -raw — Defines input format as raw binary data
• -remove_dc — Remove DC offset from each frame
• -remove_noise — Remove noise with spectral subtraction in mel-energies
• -remove_silence — Enables VAD, removes silence frames from processing
• -round_filters — Round mel filter frequencies to DFT points
• -runlen — If a control file was specified, the number of utterances to process, or -1 for all
• -samprate — Sampling rate
• -seed — Seed for random number generator; if less than zero, pick our own
• -smoothspec — Write out cepstral-smoothed logspectral files
• -spec2cep — Input is log spectral files, output is cepstral files
• -sph2pipe — Input is NIST sphere (possibly with Shorten), use sph2pipe to convert
• -transform — Which type of transform to use to calculate cepstra (legacy, dct, or htk)
• -unit_area — Normalize mel filters to unit area
• -upperf — Upper edge of filters
• -vad_postspeech — Num of silence frames to keep after from speech to silence.
• -vad_prespeech — Num of speech frames to keep before silence to speech.
• -vad_startspeech — Num of speech frames to trigger vad from silence to speech.
• -vad_threshold — Threshold for decision between noise and silence frames. Log-ratio between signal level and noise level.
• -verbose — Show input filenames
• -warp_params — defining the warping function
• -warp_type — Warping function type (or shape)
• -whichchan — Channel to process (numbered from 1), or 0 to mix all channels
• -wlen — Hamming window length

🚨 THE PART WHERE I NEED YOU TO LOCK IN 🚨

Currently the only kind of features supported are MFCCs (mel-frequency cepstral coefficients). There are numerous options which control the properties of the output features. 🧚

It is VERY important that you document the specific set of flags used to create any given set of feature files, since this information is NOT recorded in the files themselves, and any mismatch between the parameters used to extract features for recognition and those used to extract features for training will cause recognition to fail. 💀

Like bestie I am not joking, write down your flags. The files will not remember for you. Recognition will simply fail. Not me watching you lose a whole training run because you forgot which -nfilt you used 😭

👑 AUTHOR 👑

Written by numerous people at CMU from 1994 onwards. This manual page by David Huggins-Daines <dhuggins@cs.cmu.edu> 💌

📜 COPYRIGHT 📜

Copyright © 1994-2007 Carnegie Mellon University. See the file COPYING included with this package for more information.

Okay that's the whole page, you're all caught up 🫶 this little cutie is dated 2007-08-27 and she lives in the General Commands Manual, so go forth and extract those features, mwah 💅✨🌸