STRUCT DMX_BUFFER(9)

💅 struct dmx_buffer(9) — Kernel API Manual 💅

okay bestie, welcome to the Kernel API Manual corner where we make kernel structs make sense 💖 this one is literally all about the dmx buffer info and it's kinda iconic.

💖 NAME 💖

• struct dmx_buffer — dmx buffer info ✨ like, that's the whole vibe: it's the struct that carries dmx buffer info, no cap.

🌸 SYNOPSIS 🌸

here's the exact shape of it, bestie:

struct dmx_buffer {
    __u32 index;
    __u32 bytesused;
    __u32 offset;
    __u32 length;
    __u32 flags;
    __u32 count;
};

🎀 Members 🎀

• index — the id number of the buffer 👑 it's the little name tag.
• bytesused — number of bytes occupied by data in the buffer (payload); the actual payload amount, periodt.
• offset — for buffers with memory == DMX_MEMORY_MMAP; offset from the start of the device memory for this plane, (or a "cookie" that should be passed to mmap as offset) 🍪 yes, a cookie, we love a mysterious little offset.
• length — size in bytes of the buffer 📏 that's the size, full stop.
• flags — bit array of buffer flags as defined by enum dmx_buffer_flags. Filled only at DMX_DQBUF 🚩 so don't expect it to be filled before then.
• count — monotonic counter for filled buffers. Helps to identify data stream loses. Filled only at DMX_DQBUF 🔢 it's giving "monotonic counter realness" and it's only filled at DMX_DQBUF.

🦋 Description 🦋

Contains data exchanged by application and driver using one of the streaming I/O methods 💫 that's the whole point of this struct, bestie.

🚨 Please notice: for DMX_QBUF, only index should be filled. On DMX_DQBUF calls, all fields will be filled by the Kernel. so like, don't overfill it on DMX_QBUF, okay? the Kernel handles the rest on DMX_DQBUF 🫶

🌈 SEE ALSO 🌈

• Kernel file ./include/uapi/linux/dvb/dmx.h
• enum dmx_output(9)
• enum dmx_input(9)
• enum dmx_ts_pes(9)
• struct dmx_filter(9)
• struct dmx_sct_filter_params(9)
• struct dmx_pes_filter_params(9)
• struct dmx_stc(9)
• enum dmx_buffer_flags(9)
• struct dmx_requestbuffers(9)
• struct dmx_exportbuffer(9)

mwah 💋 this page came from ./include/uapi/linux/dvb, dated October 2026, and it's serving struct dmx_buffer(9) realness 🫶✨