STRUCT SND_COMPR_OPS(9)

🎀 struct snd_compr_ops(9) — compressed path DSP operations 🎀

okay bestie, welcome to the Kernel API Manual ✨ this page is literally all about struct snd_compr_ops, aka the compressed path DSP operations squad. it's giving “driver callback central,” and we are going through every single member with zero skips, fr fr 💅

💖 NAME 💖

struct snd_compr_ops — compressed path DSP operations. iconic. no notes. 🌸

✨ SYNOPSIS ✨

here's the whole struct, copied exactly so nobody comes for me:

       struct snd_compr_ops {
           int (*open)(struct snd_compr_stream *stream);
           int (*free)(struct snd_compr_stream *stream);
           int (*set_params)(struct snd_compr_stream *stream, struct
       snd_compr_params *params);
           int (*get_params)(struct snd_compr_stream *stream, struct snd_codec
       *params);
           int (*set_metadata)(struct snd_compr_stream *stream, struct
       snd_compr_metadata *metadata);
           int (*get_metadata)(struct snd_compr_stream *stream, struct
       snd_compr_metadata *metadata);
           int (*trigger)(struct snd_compr_stream *stream, int cmd);
           int (*pointer)(struct snd_compr_stream *stream, struct
       snd_compr_tstamp64 *tstamp);
           int (*copy)(struct snd_compr_stream *stream, char __user *buf,
       size_t count);
           int (*mmap)(struct snd_compr_stream *stream, struct vm_area_struct
       *vma);
           int (*ack)(struct snd_compr_stream *stream, size_t bytes);
           int (*get_caps) (struct snd_compr_stream *stream, struct
       snd_compr_caps *caps);
           int (*get_codec_caps) (struct snd_compr_stream *stream, struct
       snd_compr_codec_caps *codec);
         #if IS_ENABLED(CONFIG_SND_COMPRESS_ACCEL);
           int (*task_create) (struct snd_compr_stream *stream, struct
       snd_compr_task_runtime *task);
           int (*task_start) (struct snd_compr_stream *stream, struct
       snd_compr_task_runtime *task);
           int (*task_stop) (struct snd_compr_stream *stream, struct
       snd_compr_task_runtime *task);
           int (*task_free) (struct snd_compr_stream *stream, struct
       snd_compr_task_runtime *task);
         #endif;
        };

🌸 Members 🌸

member-by-member, no skips, let's go 🫶

• open — Open the compressed stream. This callback is mandatory and shall keep dsp ready to receive the stream parameter 💖
• free — Close the compressed stream. mandatory. yes bestie, it's required 🎀
• set_params — Sets the compressed stream parameters. mandatory. This can be called during stream creation only, to set codec params and the stream properties ✨
• get_params — retrieve the codec parameters. mandatory 🔥
• set_metadata — Set the metadata values for a stream 🦋
• get_metadata — retrieves the requested metadata values from stream. no cap 👑
• trigger — Trigger operations like start, pause, resume, drain, stop. This callback is mandatory ⭐
• pointer — Retrieve current h/w pointer information. Mandatory. periodt 💅
• copy — Copy the compressed data to/from userspace. Optional. Can't be implemented if DSP supports mmap 🫶
• mmap — DSP mmap method to mmap DSP memory 🌈
• ack — Ack for DSP when data is written to audio buffer. Optional. Not valid if copy is implemented 🙈
• get_caps — Retrieve DSP capabilities. mandatory 💜
• get_codec_caps — Retrieve capabilities for a specific codec. mandatory 🍓
• task_create — Create a set of input/output buffers for accel operations 🧚
• task_start — Start (queue) a task for accel operations 🦋
• task_stop — Stop (dequeue) a task for accel operations 💀
• task_free — Free a set of input/output buffers for accel operations 🎀

🔎 SEE ALSO 🔎

Kernel file ./include/sound/compress_driver.h plus the whole squad: struct snd_compr_task_runtime(9), struct snd_compr_runtime(9), struct snd_compr_stream(9), struct snd_compr(9), snd_compr_use_pause_in_draining(9), snd_compr_set_runtime_buffer(9). go read up, iykyk 💖

xoxo, your kernel bestie 💅 — source/version: ./include/sound, dated October 2026 🎀