mirror of
https://github.com/alsa-project/alsa-lib.git
synced 2025-10-31 22:25:35 -04:00
Implemented snd_pcm_rewind() for the dmix plugin
This commit is contained in:
Jaroslav Kysela
parent
8f16428f9c
commit
70b11d614d
7 changed files with 459 additions and 28 deletions
|
|
@ -213,6 +213,70 @@ static void mix_areas(snd_pcm_direct_t *dmix,
|
|||
}
|
||||
}
|
||||
|
||||
static void remix_areas(snd_pcm_direct_t *dmix,
|
||||
const snd_pcm_channel_area_t *src_areas,
|
||||
const snd_pcm_channel_area_t *dst_areas,
|
||||
snd_pcm_uframes_t src_ofs,
|
||||
snd_pcm_uframes_t dst_ofs,
|
||||
snd_pcm_uframes_t size)
|
||||
{
|
||||
unsigned int src_step, dst_step;
|
||||
unsigned int chn, dchn, channels, sample_size;
|
||||
mix_areas_t *do_remix_areas;
|
||||
|
||||
channels = dmix->channels;
|
||||
switch (dmix->shmptr->s.format) {
|
||||
case SND_PCM_FORMAT_S16_LE:
|
||||
case SND_PCM_FORMAT_S16_BE:
|
||||
sample_size = 2;
|
||||
do_remix_areas = (mix_areas_t *)dmix->u.dmix.remix_areas_16;
|
||||
break;
|
||||
case SND_PCM_FORMAT_S32_LE:
|
||||
case SND_PCM_FORMAT_S32_BE:
|
||||
sample_size = 4;
|
||||
do_remix_areas = (mix_areas_t *)dmix->u.dmix.remix_areas_32;
|
||||
break;
|
||||
case SND_PCM_FORMAT_S24_3LE:
|
||||
sample_size = 3;
|
||||
do_remix_areas = (mix_areas_t *)dmix->u.dmix.remix_areas_24;
|
||||
break;
|
||||
case SND_PCM_FORMAT_U8:
|
||||
sample_size = 1;
|
||||
do_remix_areas = (mix_areas_t *)dmix->u.dmix.remix_areas_u8;
|
||||
break;
|
||||
default:
|
||||
return;
|
||||
}
|
||||
if (dmix->interleaved) {
|
||||
/*
|
||||
* process all areas in one loop
|
||||
* it optimizes the memory accesses for this case
|
||||
*/
|
||||
do_remix_areas(size * channels,
|
||||
(unsigned char *)dst_areas[0].addr + sample_size * dst_ofs * channels,
|
||||
(unsigned char *)src_areas[0].addr + sample_size * src_ofs * channels,
|
||||
dmix->u.dmix.sum_buffer + dst_ofs * channels,
|
||||
sample_size,
|
||||
sample_size,
|
||||
sizeof(signed int));
|
||||
return;
|
||||
}
|
||||
for (chn = 0; chn < channels; chn++) {
|
||||
dchn = dmix->bindings ? dmix->bindings[chn] : chn;
|
||||
if (dchn >= dmix->shmptr->s.channels)
|
||||
continue;
|
||||
src_step = src_areas[chn].step / 8;
|
||||
dst_step = dst_areas[dchn].step / 8;
|
||||
do_remix_areas(size,
|
||||
((unsigned char *)dst_areas[dchn].addr + dst_areas[dchn].first / 8) + dst_ofs * dst_step,
|
||||
((unsigned char *)src_areas[chn].addr + src_areas[chn].first / 8) + src_ofs * src_step,
|
||||
dmix->u.dmix.sum_buffer + channels * dst_ofs + chn,
|
||||
dst_step,
|
||||
src_step,
|
||||
channels * sizeof(signed int));
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* if no concurrent access is allowed in the mixing routines, we need to protect
|
||||
* the area via semaphore
|
||||
|
|
@ -234,7 +298,7 @@ static void snd_pcm_dmix_sync_area(snd_pcm_t *pcm)
|
|||
{
|
||||
snd_pcm_direct_t *dmix = pcm->private_data;
|
||||
snd_pcm_uframes_t slave_hw_ptr, slave_appl_ptr, slave_size;
|
||||
snd_pcm_uframes_t appl_ptr, size;
|
||||
snd_pcm_uframes_t appl_ptr, size, transfer;
|
||||
const snd_pcm_channel_area_t *src_areas, *dst_areas;
|
||||
|
||||
/* calculate the size to transfer */
|
||||
|
|
@ -247,6 +311,27 @@ static void snd_pcm_dmix_sync_area(snd_pcm_t *pcm)
|
|||
if (size >= pcm->boundary / 2)
|
||||
size = pcm->boundary - size;
|
||||
|
||||
/* the slave_app_ptr can be far behing 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);
|
||||
if (slave_size > dmix->slave_buffer_size) {
|
||||
transfer = dmix->slave_buffer_size - slave_size;
|
||||
if (transfer > size)
|
||||
transfer = size;
|
||||
dmix->last_appl_ptr += transfer;
|
||||
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;
|
||||
if (! size)
|
||||
return;
|
||||
if (size >= pcm->boundary / 2)
|
||||
size = pcm->boundary - size;
|
||||
}
|
||||
|
||||
/* check the available size in the slave PCM buffer */
|
||||
slave_hw_ptr = dmix->slave_hw_ptr;
|
||||
/* don't write on the last active period - this area may be cleared
|
||||
|
|
@ -276,7 +361,7 @@ static void snd_pcm_dmix_sync_area(snd_pcm_t *pcm)
|
|||
dmix->slave_appl_ptr %= dmix->slave_boundary;
|
||||
dmix_down_sem(dmix);
|
||||
for (;;) {
|
||||
snd_pcm_uframes_t transfer = size;
|
||||
transfer = size;
|
||||
if (appl_ptr + transfer > pcm->buffer_size)
|
||||
transfer = pcm->buffer_size - appl_ptr;
|
||||
if (slave_appl_ptr + transfer > dmix->slave_buffer_size)
|
||||
|
|
@ -564,15 +649,78 @@ static int snd_pcm_dmix_pause(snd_pcm_t *pcm ATTRIBUTE_UNUSED, int enable ATTRIB
|
|||
return -EIO;
|
||||
}
|
||||
|
||||
static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_uframes_t frames ATTRIBUTE_UNUSED)
|
||||
static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
|
||||
{
|
||||
#if 0
|
||||
/* FIXME: substract samples from the mix ring buffer, too? */
|
||||
snd_pcm_direct_t *dmix = pcm->private_data;
|
||||
snd_pcm_uframes_t slave_appl_ptr, slave_size;
|
||||
snd_pcm_uframes_t appl_ptr, size, transfer, result;
|
||||
const snd_pcm_channel_area_t *src_areas, *dst_areas;
|
||||
|
||||
if (dmix->state == SND_PCM_STATE_RUNNING ||
|
||||
dmix->state == SND_PCM_STATE_DRAINING)
|
||||
return snd_pcm_dmix_hwsync(pcm);
|
||||
|
||||
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);
|
||||
if (frames < size)
|
||||
size = frames;
|
||||
snd_pcm_mmap_appl_backward(pcm, size);
|
||||
frames -= size;
|
||||
if (!frames)
|
||||
return size;
|
||||
result = size;
|
||||
|
||||
if (dmix->hw_ptr < dmix->appl_ptr)
|
||||
size = dmix->appl_ptr - dmix->hw_ptr;
|
||||
else
|
||||
size = dmix->appl_ptr + (pcm->boundary - dmix->hw_ptr);
|
||||
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);
|
||||
if (slave_size < size)
|
||||
size = slave_size;
|
||||
frames -= size;
|
||||
result += size;
|
||||
|
||||
/* add sample areas here */
|
||||
src_areas = snd_pcm_mmap_areas(pcm);
|
||||
dst_areas = snd_pcm_mmap_areas(dmix->spcm);
|
||||
dmix->last_appl_ptr -= size;
|
||||
dmix->last_appl_ptr %= pcm->boundary;
|
||||
appl_ptr = dmix->last_appl_ptr % pcm->buffer_size;
|
||||
dmix->slave_appl_ptr -= size;
|
||||
dmix->slave_appl_ptr %= dmix->slave_boundary;
|
||||
slave_appl_ptr = dmix->slave_appl_ptr % dmix->slave_buffer_size;
|
||||
dmix_down_sem(dmix);
|
||||
for (;;) {
|
||||
transfer = size;
|
||||
if (appl_ptr + transfer > pcm->buffer_size)
|
||||
transfer = pcm->buffer_size - appl_ptr;
|
||||
if (slave_appl_ptr + transfer > dmix->slave_buffer_size)
|
||||
transfer = dmix->slave_buffer_size - slave_appl_ptr;
|
||||
remix_areas(dmix, src_areas, dst_areas, appl_ptr, slave_appl_ptr, transfer);
|
||||
size -= transfer;
|
||||
if (! size)
|
||||
break;
|
||||
slave_appl_ptr += transfer;
|
||||
slave_appl_ptr %= dmix->slave_buffer_size;
|
||||
appl_ptr += transfer;
|
||||
appl_ptr %= pcm->buffer_size;
|
||||
}
|
||||
dmix->last_appl_ptr -= frames;
|
||||
dmix->last_appl_ptr %= pcm->boundary;
|
||||
dmix->slave_appl_ptr -= frames;
|
||||
dmix->slave_appl_ptr %= dmix->slave_boundary;
|
||||
dmix_up_sem(dmix);
|
||||
|
||||
snd_pcm_mmap_appl_backward(pcm, frames);
|
||||
return frames;
|
||||
#else
|
||||
return -EIO;
|
||||
#endif
|
||||
|
||||
return result + frames;
|
||||
}
|
||||
|
||||
static snd_pcm_sframes_t snd_pcm_dmix_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue