snd_pcm_capture_avail(9)

✨ snd_pcm_capture_avail(9) ✨

okay so this is a page from the Kernel API Manual, bestie, and it's about snd_pcm_capture_avail — literally the function that tells you how much readable space your capture stream has. let's get into it 🎀

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🌸 NAME 🌸

snd_pcm_capture_avail — get the available (readable) space for capture 💖

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🦋 SYNOPSIS 🦋

snd_pcm_uframes_t snd_pcm_capture_avail (struct snd_pcm_runtime *runtime
);

like yes that's the whole signature, it's giving "short and iconic" ✨

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🎀 ARGUMENTS 🎀

• runtime — the PCM runtime instance. that's your girl, she holds all the state 🫶

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💅 DESCRIPTION 💅

so the result lands somewhere between 0 ... (boundary - 1). no cap, that's the range, and it's inclusive-ish in the way the manpage says it so i'm saying it 💀

lowkey important: it's 0 ... (boundary - 1), not just "0 to boundary". don't come for me, i'm just the messenger 🙈

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🔥 RETURN 🔥

the available frame size ⭐

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👑 SEE ALSO 👑

kernel file ./include/sound/pcm.h — and honestly the whole friend group is here, so:

• snd_pcm_stream_linked(9)
• snd_pcm_stream_lock_irqsave(9)
• snd_pcm_stream_lock_irqsave_nested(9)
• snd_pcm_group_for_each_entry(9)
• snd_pcm_running(9)
• __snd_pcm_set_state(9)
• bytes_to_samples(9)
• bytes_to_frames(9)
• samples_to_bytes(9)
• frames_to_bytes(9)
• frame_aligned(9)
• snd_pcm_lib_buffer_bytes(9)
• snd_pcm_lib_period_bytes(9)
• snd_pcm_playback_avail(9)
• snd_pcm_playback_hw_avail(9)
• snd_pcm_capture_hw_avail(9)
• snd_pcm_playback_ready(9)
• snd_pcm_capture_ready(9)
• snd_pcm_playback_data(9)
• snd_pcm_playback_empty(9)
• snd_pcm_capture_empty(9)
• snd_pcm_trigger_done(9)
• params_channels(9)
• params_rate(9)
• params_period_size(9)
• params_periods(9)
• params_buffer_size(9)
• params_buffer_bytes(9)
• snd_pcm_hw_constraint_single(9)
• snd_pcm_format_cpu_endian(9)
• snd_pcm_set_sync(9)
• snd_pcm_set_runtime_buffer(9)
• snd_pcm_gettime(9)
• snd_pcm_set_fixed_buffer(9)
• snd_pcm_set_fixed_buffer_all(9)
• snd_pcm_sgbuf_get_addr(9)
• snd_pcm_sgbuf_get_chunk_size(9)
• snd_pcm_limit_isa_dma_size(9)
• snd_pcm_direction_name(9)
• snd_pcm_stream_str(9)
• snd_pcm_chmap_substream(9)
• pcm_format_to_bits(9)
• pcm_for_each_format(9)

like that's a whole roster, go read them, iykyk 💜

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and that's the page!! mwah 💋 this gem lives under ./include/sound, dated October 2026, and it's literally the snd_pcm_capture_avail(9) manual page — main character energy only 👑✨