mirrors/alsa-lib
1
0
Fork 0
mirror of https://github.com/alsa-project/alsa-lib.git synced 2025-11-05 13:30:00 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Better PCM mmap API. Fixed pcm_multi

Browse source
This commit is contained in:
Abramo Bagnara 2001-04-13 15:40:53 +00:00
parent c4f95f48c3
commit 6a3b962d06
16 changed files with 279 additions and 279 deletions
Download patch file Download diff file Expand all files Collapse all files

66
src/pcm/pcm_mmap.c
View file

@ -44,36 +44,6 @@ size_t page_align(size_t size)
return size;
}
snd_pcm_uframes_t snd_pcm_mmap_playback_xfer(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
snd_pcm_uframes_t cont;
snd_pcm_uframes_t avail = snd_pcm_mmap_playback_avail(pcm);
if (avail < frames)
frames = avail;
cont = pcm->buffer_size - *pcm->appl_ptr % pcm->buffer_size;
if (cont < frames)
frames = cont;
return frames;
}
snd_pcm_uframes_t snd_pcm_mmap_capture_xfer(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
snd_pcm_uframes_t cont;
snd_pcm_uframes_t avail = snd_pcm_mmap_capture_avail(pcm);
if (avail < frames)
frames = avail;
cont = pcm->buffer_size - *pcm->appl_ptr % pcm->buffer_size;
if (cont < frames)
frames = cont;
return frames;
}
snd_pcm_uframes_t snd_pcm_mmap_hw_offset(snd_pcm_t *pcm)
{
assert(pcm);
return *pcm->hw_ptr % pcm->buffer_size;
}
void snd_pcm_mmap_appl_backward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
snd_pcm_sframes_t appl_ptr = *pcm->appl_ptr;
@ -115,28 +85,18 @@ static snd_pcm_uframes_t snd_pcm_mmap_write_areas(snd_pcm_t *pcm,
snd_pcm_uframes_t offset,
snd_pcm_uframes_t size)
{
const snd_pcm_channel_area_t *pcm_areas;
snd_pcm_uframes_t pcm_offset;
snd_pcm_uframes_t xfer = size;
assert(snd_pcm_mmap_playback_avail(pcm) >= size);
pcm_areas = snd_pcm_mmap_areas(pcm);
pcm_offset = snd_pcm_mmap_offset(pcm);
while (size > 0) {
const snd_pcm_channel_area_t *pcm_areas;
snd_pcm_uframes_t pcm_offset;
snd_pcm_uframes_t frames = size;
snd_pcm_uframes_t cont = pcm->buffer_size - pcm_offset;
int err;
if (frames > cont)
frames = cont;
snd_pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames);
snd_pcm_areas_copy(pcm_areas, pcm_offset,
areas, offset,
pcm->channels,
frames, pcm->format);
err = snd_pcm_mmap_forward(pcm, frames);
assert(err == (snd_pcm_sframes_t)frames);
if (frames == cont)
pcm_offset = 0;
else
pcm_offset += frames;
snd_pcm_mmap_commit(pcm, pcm_offset, frames);
offset += frames;
size -= frames;
}
@ -148,28 +108,18 @@ static snd_pcm_uframes_t snd_pcm_mmap_read_areas(snd_pcm_t *pcm,
snd_pcm_uframes_t offset,
snd_pcm_uframes_t size)
{
const snd_pcm_channel_area_t *pcm_areas;
snd_pcm_uframes_t pcm_offset;
snd_pcm_uframes_t xfer = size;
assert(snd_pcm_mmap_capture_avail(pcm) >= size);
pcm_areas = snd_pcm_mmap_areas(pcm);
pcm_offset = snd_pcm_mmap_offset(pcm);
while (size > 0) {
const snd_pcm_channel_area_t *pcm_areas;
snd_pcm_uframes_t pcm_offset;
snd_pcm_uframes_t frames = size;
snd_pcm_uframes_t cont = pcm->buffer_size - pcm_offset;
int err;
if (frames > cont)
frames = cont;
snd_pcm_mmap_begin(pcm, &pcm_areas, &pcm_offset, &frames);
snd_pcm_areas_copy(areas, offset,
pcm_areas, pcm_offset,
pcm->channels,
frames, pcm->format);
err = snd_pcm_mmap_forward(pcm, frames);
assert(err == (snd_pcm_sframes_t)frames);
if (frames == cont)
pcm_offset = 0;
else
pcm_offset += frames;
snd_pcm_mmap_commit(pcm, pcm_offset, frames);
offset += frames;
size -= frames;
}