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https://github.com/alsa-project/alsa-lib.git
synced 2025-11-03 09:01:52 -05:00
- added snd_pcm_mmap_begin_avail function; it is optimized for use after
snd_pcm_avail_update() call - fixed broken hw_ptr management inside snd_pcm_plugin code
This commit is contained in:
Jaroslav Kysela
parent
b63e44aab0
commit
b7b11c3558
4 changed files with 187 additions and 69 deletions
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@ -4845,7 +4845,7 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
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snd_pcm_uframes_t *frames)
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{
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snd_pcm_uframes_t cont;
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snd_pcm_uframes_t avail;
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snd_pcm_sframes_t avail;
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snd_pcm_uframes_t f;
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assert(pcm && areas && offset && frames);
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if (pcm->stopped_areas &&
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@ -4855,7 +4855,43 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
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*areas = pcm->running_areas;
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*offset = *pcm->appl_ptr % pcm->buffer_size;
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cont = pcm->buffer_size - *offset;
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avail = snd_pcm_mmap_avail(pcm);
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avail = snd_pcm_avail_update(pcm);
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if (avail < 0)
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return avail;
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f = *frames;
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if (f > (snd_pcm_uframes_t)avail)
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f = avail;
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if (f > cont)
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f = cont;
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*frames = f;
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return 0;
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}
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/**
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* \brief Application request to access a portion of direct (mmap) area
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* \param pcm PCM handle
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* \param areas Returned mmap channel areas
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* \param offset Returned mmap area offset in area steps (== frames)
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* \param size mmap area portion size in frames (wanted on entry, contiguous available on exit)
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* \param avail available frames (result from snd_pcm_avail_update())
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* \return 0 on success otherwise a negative error code
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*/
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int snd_pcm_mmap_begin_avail(snd_pcm_t *pcm,
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const snd_pcm_channel_area_t **areas,
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snd_pcm_uframes_t *offset,
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snd_pcm_uframes_t *frames,
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snd_pcm_uframes_t avail)
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{
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snd_pcm_uframes_t cont;
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snd_pcm_uframes_t f;
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assert(pcm && areas && offset && frames && avail <= pcm->buffer_size);
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if (pcm->stopped_areas &&
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snd_pcm_state(pcm) != SND_PCM_STATE_RUNNING)
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*areas = pcm->stopped_areas;
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else
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*areas = pcm->running_areas;
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*offset = *pcm->appl_ptr % pcm->buffer_size;
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cont = pcm->buffer_size - *offset;
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f = *frames;
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if (f > avail)
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f = avail;
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@ -4879,7 +4915,7 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
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* count that snd_pcm_mmap_begin() returned. Each call to snd_pcm_mmap_begin()
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* must be followed by a call to snd_pcm_mmap_commit().
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*
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* Example:
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* Example #1:
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\code
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double phase = 0;
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const snd_pcm_area_t *areas;
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@ -4894,6 +4930,27 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
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err = snd_pcm_mmap_commit(pcm_handle, offset, frames);
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if (err < 0)
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error(err);
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\endcode
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*
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* Example #2 (determine available frame count at beginning):
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\code
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double phase = 0;
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const snd_pcm_area_t *areas;
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snd_pcm_sframes_t avail;
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snd_pcm_uframes_t offset, frames;
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avail = snd_pcm_avail_update(pcm);
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if (avail < 0)
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error(avail);
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frames = frame_buffer_size > avail ? avail : frame_buffer_size;
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err = snd_pcm_mmap_begin_avail(pcm_handle, &areas, &offset, &frames, avail);
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if (err < 0)
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error(err);
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// this function fills the areas from offset with count of frames
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generate_sine(areas, offset, frames, &phase);
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err = snd_pcm_mmap_commit(pcm_handle, offset, frames);
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if (err < 0)
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error(err);
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\endcode
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*
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* Look to the \ref example_test_pcm "Sine-wave generator" example
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@ -218,7 +218,6 @@ static snd_pcm_sframes_t snd_pcm_plugin_write_areas(snd_pcm_t *pcm,
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assert(slave_frames <= snd_pcm_mmap_playback_avail(slave));
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snd_atomic_write_begin(&plugin->watom);
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snd_pcm_mmap_appl_forward(pcm, frames);
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snd_pcm_mmap_hw_forward(pcm, frames);
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err = snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
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snd_atomic_write_end(&plugin->watom);
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if (err < 0)
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@ -251,7 +250,6 @@ static snd_pcm_sframes_t snd_pcm_plugin_read_areas(snd_pcm_t *pcm,
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assert(slave_frames <= snd_pcm_mmap_capture_avail(slave));
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snd_atomic_write_begin(&plugin->watom);
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snd_pcm_mmap_appl_forward(pcm, frames);
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snd_pcm_mmap_hw_forward(pcm, frames);
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err = snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
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snd_atomic_write_end(&plugin->watom);
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if (err < 0)
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@ -303,8 +301,9 @@ int snd_pcm_plugin_mmap_commit(snd_pcm_t *pcm,
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snd_pcm_plugin_t *plugin = pcm->private_data;
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snd_pcm_t *slave = plugin->slave;
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const snd_pcm_channel_area_t *areas;
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snd_pcm_uframes_t xfer, hw_offset;
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snd_pcm_uframes_t appl_offset;
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snd_pcm_sframes_t slave_size;
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if (pcm->stream == SND_PCM_STREAM_CAPTURE) {
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snd_atomic_write_begin(&plugin->watom);
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snd_pcm_mmap_appl_forward(pcm, size);
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@ -314,32 +313,30 @@ int snd_pcm_plugin_mmap_commit(snd_pcm_t *pcm,
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slave_size = snd_pcm_avail_update(slave);
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if (slave_size < 0)
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return slave_size;
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if (slave_size == 0)
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if ((snd_pcm_uframes_t)slave_size < size)
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return -EIO;
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areas = snd_pcm_mmap_areas(pcm);
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hw_offset = snd_pcm_mmap_hw_offset(pcm);
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xfer = 0;
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appl_offset = snd_pcm_mmap_offset(pcm);
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while (size > 0 && slave_size > 0) {
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snd_pcm_uframes_t frames = size;
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snd_pcm_uframes_t cont = pcm->buffer_size - hw_offset;
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snd_pcm_uframes_t cont = pcm->buffer_size - appl_offset;
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const snd_pcm_channel_area_t *slave_areas;
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snd_pcm_uframes_t slave_offset;
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snd_pcm_uframes_t slave_frames = ULONG_MAX;
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snd_pcm_mmap_begin(slave, &slave_areas, &slave_offset, &slave_frames);
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if (frames > cont)
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frames = cont;
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frames = plugin->write(pcm, areas, hw_offset, frames,
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frames = plugin->write(pcm, areas, appl_offset, frames,
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slave_areas, slave_offset, &slave_frames);
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snd_atomic_write_begin(&plugin->watom);
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snd_pcm_mmap_appl_forward(pcm, frames);
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snd_pcm_mmap_hw_forward(pcm, frames);
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snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
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snd_atomic_write_end(&plugin->watom);
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xfer += frames;
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if (frames == cont)
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hw_offset = 0;
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appl_offset = 0;
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else
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hw_offset += frames;
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appl_offset += frames;
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size -= frames;
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slave_size -= slave_frames;
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}
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@ -351,46 +348,56 @@ snd_pcm_sframes_t snd_pcm_plugin_avail_update(snd_pcm_t *pcm)
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{
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snd_pcm_plugin_t *plugin = pcm->private_data;
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snd_pcm_t *slave = plugin->slave;
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const snd_pcm_channel_area_t *areas;
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snd_pcm_uframes_t xfer, hw_offset, size;
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snd_pcm_sframes_t slave_size;
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slave_size = snd_pcm_avail_update(slave);
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if (slave_size <= 0)
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if (pcm->stream == SND_PCM_STREAM_CAPTURE &&
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pcm->access != SND_PCM_ACCESS_RW_INTERLEAVED &&
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pcm->access != SND_PCM_ACCESS_RW_NONINTERLEAVED)
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goto _capture;
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if (plugin->client_frames) {
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plugin->hw_ptr = plugin->client_frames(slave, *slave->hw_ptr);
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if (slave_size <= 0)
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return slave_size;
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return plugin->client_frames(pcm, slave_size);
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} else {
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plugin->hw_ptr = *slave->hw_ptr;
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return slave_size;
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if (pcm->stream == SND_PCM_STREAM_PLAYBACK ||
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pcm->access == SND_PCM_ACCESS_RW_INTERLEAVED ||
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pcm->access == SND_PCM_ACCESS_RW_NONINTERLEAVED)
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return (plugin->client_frames ?
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plugin->client_frames(pcm, slave_size) :
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slave_size);
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xfer = snd_pcm_mmap_capture_avail(pcm);
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size = pcm->buffer_size - xfer;
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areas = snd_pcm_mmap_areas(pcm);
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hw_offset = snd_pcm_mmap_hw_offset(pcm);
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while (size && slave_size) {
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snd_pcm_uframes_t frames = size;
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snd_pcm_uframes_t cont = pcm->buffer_size - hw_offset;
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const snd_pcm_channel_area_t *slave_areas;
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snd_pcm_uframes_t slave_offset;
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snd_pcm_uframes_t slave_frames = ULONG_MAX;
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snd_pcm_mmap_begin(slave, &slave_areas, &slave_offset, &slave_frames);
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if (frames > cont)
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frames = cont;
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frames = plugin->read(pcm, areas, hw_offset, frames,
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slave_areas, slave_offset, &slave_frames);
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snd_atomic_write_begin(&plugin->watom);
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snd_pcm_mmap_hw_forward(pcm, frames);
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snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
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snd_atomic_write_end(&plugin->watom);
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xfer += frames;
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if (frames == cont)
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hw_offset = 0;
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else
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hw_offset += frames;
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size -= frames;
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slave_size -= slave_frames;
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}
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return xfer;
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_capture:
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{
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const snd_pcm_channel_area_t *areas;
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snd_pcm_uframes_t xfer, hw_offset, size;
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xfer = snd_pcm_mmap_capture_avail(pcm);
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size = pcm->buffer_size - xfer;
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areas = snd_pcm_mmap_areas(pcm);
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hw_offset = snd_pcm_mmap_hw_offset(pcm);
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while (size > 0 && slave_size > 0) {
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snd_pcm_uframes_t frames = size;
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snd_pcm_uframes_t cont = pcm->buffer_size - hw_offset;
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const snd_pcm_channel_area_t *slave_areas;
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snd_pcm_uframes_t slave_offset;
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snd_pcm_uframes_t slave_frames = ULONG_MAX;
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snd_pcm_mmap_begin(slave, &slave_areas, &slave_offset, &slave_frames);
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if (frames > cont)
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frames = cont;
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frames = plugin->read(pcm, areas, hw_offset, frames,
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slave_areas, slave_offset, &slave_frames);
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snd_atomic_write_begin(&plugin->watom);
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snd_pcm_mmap_hw_forward(pcm, frames);
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snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
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snd_atomic_write_end(&plugin->watom);
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xfer += frames;
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if (frames == cont)
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hw_offset = 0;
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else
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hw_offset += frames;
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size -= frames;
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slave_size -= slave_frames;
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}
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return xfer;
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}
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}
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int snd_pcm_plugin_mmap(snd_pcm_t *pcm)
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