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pcm: introduce pcm_frame_diff and pcm_frame_diff2 helpers

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Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Jaroslav Kysela 2020-10-13 20:10:49 +02:00
parent a6c8ac0c85
commit 6d06fcc285
4 changed files with 30 additions and 40 deletions
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33
src/pcm/pcm_dmix.c
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@ -319,18 +319,13 @@ static void snd_pcm_dmix_sync_area(snd_pcm_t *pcm)
/* check the available size in the local buffer
* last_appl_ptr keeps the last updated position
*/
size = dmix->appl_ptr - dmix->last_appl_ptr;
size = pcm_frame_diff2(dmix->appl_ptr, dmix->last_appl_ptr, pcm->boundary);
if (! size)
return;
if (size >= pcm->boundary / 2)
size = pcm->boundary - size;
/* the slave_app_ptr can be far behind the slave_hw_ptr */
/* reduce mixing and errors here - just skip not catched writes */
if (dmix->slave_hw_ptr <= dmix->slave_appl_ptr)
slave_size = dmix->slave_appl_ptr - dmix->slave_hw_ptr;
else
slave_size = dmix->slave_appl_ptr + (dmix->slave_boundary - dmix->slave_hw_ptr);
slave_size = pcm_frame_diff(dmix->slave_appl_ptr, dmix->slave_hw_ptr, dmix->slave_boundary);
if (slave_size > dmix->slave_buffer_size) {
transfer = dmix->slave_buffer_size - slave_size;
if (transfer > size)
@ -339,11 +334,9 @@ static void snd_pcm_dmix_sync_area(snd_pcm_t *pcm)
dmix->last_appl_ptr %= pcm->boundary;
dmix->slave_appl_ptr += transfer;
dmix->slave_appl_ptr %= dmix->slave_boundary;
size = dmix->appl_ptr - dmix->last_appl_ptr;
size = pcm_frame_diff2(dmix->appl_ptr, dmix->last_appl_ptr, pcm->boundary);
if (! size)
return;
if (size >= pcm->boundary / 2)
size = pcm->boundary - size;
}
/* check the available size in the slave PCM buffer */
@ -355,10 +348,7 @@ static void snd_pcm_dmix_sync_area(snd_pcm_t *pcm)
slave_hw_ptr += dmix->slave_buffer_size;
if (slave_hw_ptr >= dmix->slave_boundary)
slave_hw_ptr -= dmix->slave_boundary;
if (slave_hw_ptr < dmix->slave_appl_ptr)
slave_size = slave_hw_ptr + (dmix->slave_boundary - dmix->slave_appl_ptr);
else
slave_size = slave_hw_ptr - dmix->slave_appl_ptr;
slave_size = pcm_frame_diff(slave_hw_ptr, dmix->slave_appl_ptr, dmix->slave_boundary);
if (slave_size < size)
size = slave_size;
if (! size)
@ -726,10 +716,7 @@ static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t f
* So they can be remixed.
*/
if (dmix->last_appl_ptr < dmix->appl_ptr)
size = dmix->appl_ptr - dmix->last_appl_ptr;
else
size = dmix->appl_ptr + (pcm->boundary - dmix->last_appl_ptr);
size = pcm_frames_diff(dmix->last_appl_ptr, dmix->appl_ptr, pcm->boundary);
if (frames < size)
size = frames;
snd_pcm_mmap_appl_backward(pcm, size);
@ -741,16 +728,10 @@ static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t f
/* Always at this point last_appl_ptr == appl_ptr
* So (appl_ptr - hw_ptr) indicates the frames which can be remixed
*/
if (dmix->hw_ptr < dmix->appl_ptr)
size = dmix->appl_ptr - dmix->hw_ptr;
else
size = dmix->appl_ptr + (pcm->boundary - dmix->hw_ptr);
size = pcm_frames_diff(dmix->appl_ptr, dmix->hw_ptr, pcm->boundary);
if (size > frames)
size = frames;
if (dmix->slave_hw_ptr < dmix->slave_appl_ptr)
slave_size = dmix->slave_appl_ptr - dmix->slave_hw_ptr;
else
slave_size = dmix->slave_appl_ptr + (pcm->boundary - dmix->slave_hw_ptr);
slave_size = pcm_frames_diff(dmix->slave_appl_ptr, dmix->slave_hw_ptr, pcm->boundary);
if (slave_size < size)
size = slave_size;