- 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 2001-12-09 18:41:23 +00:00
parent b63e44aab0
commit b7b11c3558
4 changed files with 187 additions and 69 deletions

View File

@ -790,6 +790,11 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
const snd_pcm_channel_area_t **areas,
snd_pcm_uframes_t *offset,
snd_pcm_uframes_t *frames);
int snd_pcm_mmap_begin_avail(snd_pcm_t *pcm,
const snd_pcm_channel_area_t **areas,
snd_pcm_uframes_t *offset,
snd_pcm_uframes_t *frames,
snd_pcm_uframes_t avail);
int snd_pcm_mmap_commit(snd_pcm_t *pcm, snd_pcm_uframes_t offset,
snd_pcm_uframes_t frames);
snd_pcm_sframes_t snd_pcm_mmap_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_uframes_t size);

View File

@ -4845,7 +4845,7 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
snd_pcm_uframes_t *frames)
{
snd_pcm_uframes_t cont;
snd_pcm_uframes_t avail;
snd_pcm_sframes_t avail;
snd_pcm_uframes_t f;
assert(pcm && areas && offset && frames);
if (pcm->stopped_areas &&
@ -4855,7 +4855,43 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
*areas = pcm->running_areas;
*offset = *pcm->appl_ptr % pcm->buffer_size;
cont = pcm->buffer_size - *offset;
avail = snd_pcm_mmap_avail(pcm);
avail = snd_pcm_avail_update(pcm);
if (avail < 0)
return avail;
f = *frames;
if (f > (snd_pcm_uframes_t)avail)
f = avail;
if (f > cont)
f = cont;
*frames = f;
return 0;
}
/**
* \brief Application request to access a portion of direct (mmap) area
* \param pcm PCM handle
* \param areas Returned mmap channel areas
* \param offset Returned mmap area offset in area steps (== frames)
* \param size mmap area portion size in frames (wanted on entry, contiguous available on exit)
* \param avail available frames (result from snd_pcm_avail_update())
* \return 0 on success otherwise a negative error code
*/
int snd_pcm_mmap_begin_avail(snd_pcm_t *pcm,
const snd_pcm_channel_area_t **areas,
snd_pcm_uframes_t *offset,
snd_pcm_uframes_t *frames,
snd_pcm_uframes_t avail)
{
snd_pcm_uframes_t cont;
snd_pcm_uframes_t f;
assert(pcm && areas && offset && frames && avail <= pcm->buffer_size);
if (pcm->stopped_areas &&
snd_pcm_state(pcm) != SND_PCM_STATE_RUNNING)
*areas = pcm->stopped_areas;
else
*areas = pcm->running_areas;
*offset = *pcm->appl_ptr % pcm->buffer_size;
cont = pcm->buffer_size - *offset;
f = *frames;
if (f > avail)
f = avail;
@ -4879,7 +4915,7 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
* count that snd_pcm_mmap_begin() returned. Each call to snd_pcm_mmap_begin()
* must be followed by a call to snd_pcm_mmap_commit().
*
* Example:
* Example #1:
\code
double phase = 0;
const snd_pcm_area_t *areas;
@ -4894,6 +4930,27 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
err = snd_pcm_mmap_commit(pcm_handle, offset, frames);
if (err < 0)
error(err);
\endcode
*
* Example #2 (determine available frame count at beginning):
\code
double phase = 0;
const snd_pcm_area_t *areas;
snd_pcm_sframes_t avail;
snd_pcm_uframes_t offset, frames;
avail = snd_pcm_avail_update(pcm);
if (avail < 0)
error(avail);
frames = frame_buffer_size > avail ? avail : frame_buffer_size;
err = snd_pcm_mmap_begin_avail(pcm_handle, &areas, &offset, &frames, avail);
if (err < 0)
error(err);
// this function fills the areas from offset with count of frames
generate_sine(areas, offset, frames, &phase);
err = snd_pcm_mmap_commit(pcm_handle, offset, frames);
if (err < 0)
error(err);
\endcode
*
* Look to the \ref example_test_pcm "Sine-wave generator" example

View File

@ -218,7 +218,6 @@ static snd_pcm_sframes_t snd_pcm_plugin_write_areas(snd_pcm_t *pcm,
assert(slave_frames <= snd_pcm_mmap_playback_avail(slave));
snd_atomic_write_begin(&plugin->watom);
snd_pcm_mmap_appl_forward(pcm, frames);
snd_pcm_mmap_hw_forward(pcm, frames);
err = snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
snd_atomic_write_end(&plugin->watom);
if (err < 0)
@ -251,7 +250,6 @@ static snd_pcm_sframes_t snd_pcm_plugin_read_areas(snd_pcm_t *pcm,
assert(slave_frames <= snd_pcm_mmap_capture_avail(slave));
snd_atomic_write_begin(&plugin->watom);
snd_pcm_mmap_appl_forward(pcm, frames);
snd_pcm_mmap_hw_forward(pcm, frames);
err = snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
snd_atomic_write_end(&plugin->watom);
if (err < 0)
@ -303,8 +301,9 @@ int snd_pcm_plugin_mmap_commit(snd_pcm_t *pcm,
snd_pcm_plugin_t *plugin = pcm->private_data;
snd_pcm_t *slave = plugin->slave;
const snd_pcm_channel_area_t *areas;
snd_pcm_uframes_t xfer, hw_offset;
snd_pcm_uframes_t appl_offset;
snd_pcm_sframes_t slave_size;
if (pcm->stream == SND_PCM_STREAM_CAPTURE) {
snd_atomic_write_begin(&plugin->watom);
snd_pcm_mmap_appl_forward(pcm, size);
@ -314,32 +313,30 @@ int snd_pcm_plugin_mmap_commit(snd_pcm_t *pcm,
slave_size = snd_pcm_avail_update(slave);
if (slave_size < 0)
return slave_size;
if (slave_size == 0)
if ((snd_pcm_uframes_t)slave_size < size)
return -EIO;
areas = snd_pcm_mmap_areas(pcm);
hw_offset = snd_pcm_mmap_hw_offset(pcm);
xfer = 0;
appl_offset = snd_pcm_mmap_offset(pcm);
while (size > 0 && slave_size > 0) {
snd_pcm_uframes_t frames = size;
snd_pcm_uframes_t cont = pcm->buffer_size - hw_offset;
snd_pcm_uframes_t cont = pcm->buffer_size - appl_offset;
const snd_pcm_channel_area_t *slave_areas;
snd_pcm_uframes_t slave_offset;
snd_pcm_uframes_t slave_frames = ULONG_MAX;
snd_pcm_mmap_begin(slave, &slave_areas, &slave_offset, &slave_frames);
if (frames > cont)
frames = cont;
frames = plugin->write(pcm, areas, hw_offset, frames,
frames = plugin->write(pcm, areas, appl_offset, frames,
slave_areas, slave_offset, &slave_frames);
snd_atomic_write_begin(&plugin->watom);
snd_pcm_mmap_appl_forward(pcm, frames);
snd_pcm_mmap_hw_forward(pcm, frames);
snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
snd_atomic_write_end(&plugin->watom);
xfer += frames;
if (frames == cont)
hw_offset = 0;
appl_offset = 0;
else
hw_offset += frames;
appl_offset += frames;
size -= frames;
slave_size -= slave_frames;
}
@ -351,46 +348,56 @@ snd_pcm_sframes_t snd_pcm_plugin_avail_update(snd_pcm_t *pcm)
{
snd_pcm_plugin_t *plugin = pcm->private_data;
snd_pcm_t *slave = plugin->slave;
const snd_pcm_channel_area_t *areas;
snd_pcm_uframes_t xfer, hw_offset, size;
snd_pcm_sframes_t slave_size;
slave_size = snd_pcm_avail_update(slave);
if (slave_size <= 0)
if (pcm->stream == SND_PCM_STREAM_CAPTURE &&
pcm->access != SND_PCM_ACCESS_RW_INTERLEAVED &&
pcm->access != SND_PCM_ACCESS_RW_NONINTERLEAVED)
goto _capture;
if (plugin->client_frames) {
plugin->hw_ptr = plugin->client_frames(slave, *slave->hw_ptr);
if (slave_size <= 0)
return slave_size;
return plugin->client_frames(pcm, slave_size);
} else {
plugin->hw_ptr = *slave->hw_ptr;
return slave_size;
if (pcm->stream == SND_PCM_STREAM_PLAYBACK ||
pcm->access == SND_PCM_ACCESS_RW_INTERLEAVED ||
pcm->access == SND_PCM_ACCESS_RW_NONINTERLEAVED)
return (plugin->client_frames ?
plugin->client_frames(pcm, slave_size) :
slave_size);
xfer = snd_pcm_mmap_capture_avail(pcm);
size = pcm->buffer_size - xfer;
areas = snd_pcm_mmap_areas(pcm);
hw_offset = snd_pcm_mmap_hw_offset(pcm);
while (size && slave_size) {
snd_pcm_uframes_t frames = size;
snd_pcm_uframes_t cont = pcm->buffer_size - hw_offset;
const snd_pcm_channel_area_t *slave_areas;
snd_pcm_uframes_t slave_offset;
snd_pcm_uframes_t slave_frames = ULONG_MAX;
snd_pcm_mmap_begin(slave, &slave_areas, &slave_offset, &slave_frames);
if (frames > cont)
frames = cont;
frames = plugin->read(pcm, areas, hw_offset, frames,
slave_areas, slave_offset, &slave_frames);
snd_atomic_write_begin(&plugin->watom);
snd_pcm_mmap_hw_forward(pcm, frames);
snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
snd_atomic_write_end(&plugin->watom);
xfer += frames;
if (frames == cont)
hw_offset = 0;
else
hw_offset += frames;
size -= frames;
slave_size -= slave_frames;
}
return xfer;
_capture:
{
const snd_pcm_channel_area_t *areas;
snd_pcm_uframes_t xfer, hw_offset, size;
xfer = snd_pcm_mmap_capture_avail(pcm);
size = pcm->buffer_size - xfer;
areas = snd_pcm_mmap_areas(pcm);
hw_offset = snd_pcm_mmap_hw_offset(pcm);
while (size > 0 && slave_size > 0) {
snd_pcm_uframes_t frames = size;
snd_pcm_uframes_t cont = pcm->buffer_size - hw_offset;
const snd_pcm_channel_area_t *slave_areas;
snd_pcm_uframes_t slave_offset;
snd_pcm_uframes_t slave_frames = ULONG_MAX;
snd_pcm_mmap_begin(slave, &slave_areas, &slave_offset, &slave_frames);
if (frames > cont)
frames = cont;
frames = plugin->read(pcm, areas, hw_offset, frames,
slave_areas, slave_offset, &slave_frames);
snd_atomic_write_begin(&plugin->watom);
snd_pcm_mmap_hw_forward(pcm, frames);
snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
snd_atomic_write_end(&plugin->watom);
xfer += frames;
if (frames == cont)
hw_offset = 0;
else
hw_offset += frames;
size -= frames;
slave_size -= slave_frames;
}
return xfer;
}
}
int snd_pcm_plugin_mmap(snd_pcm_t *pcm)

View File

@ -411,29 +411,78 @@ static int direct_loop(snd_pcm_t *handle,
{
double phase = 0;
const snd_pcm_channel_area_t *my_areas;
snd_pcm_uframes_t offset, frames;
snd_pcm_uframes_t offset, frames, size;
snd_pcm_sframes_t avail;
snd_pcm_state_t state;
int err, first = 1;
while (1) {
frames = period_size;
err = snd_pcm_mmap_begin(handle, &my_areas, &offset, &frames);
if (err < 0) {
printf("MMAP begin error: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
generate_sine(my_areas, offset, frames, &phase);
err = snd_pcm_mmap_commit(handle, offset, frames);
if (err < 0) {
printf("MMAP commit error: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
if (frames == 0 && first) { /* trigger playback */
first = 0;
err = snd_pcm_start(handle);
state = snd_pcm_state(handle);
if (state == SND_PCM_STATE_XRUN) {
err = xrun_recovery(handle, -EPIPE);
if (err < 0) {
printf("Start error: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
printf("XRUN recovery failed: %s\n", snd_strerror(err));
return err;
}
first = 1;
} else if (state == SND_PCM_STATE_SUSPENDED) {
err = xrun_recovery(handle, -ESTRPIPE);
if (err < 0) {
printf("SUSPEND recovery failed: %s\n", snd_strerror(err));
return err;
}
}
avail = snd_pcm_avail_update(handle);
if (avail < 0) {
err = xrun_recovery(handle, avail);
if (err < 0) {
printf("avail update failed: %s\n", snd_strerror(err));
return err;
}
first = 1;
continue;
}
if (avail < period_size) {
if (first) {
first = 0;
err = snd_pcm_start(handle);
if (err < 0) {
printf("Start error: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
} else {
err = snd_pcm_wait(handle, -1);
if (err < 0) {
if ((err = xrun_recovery(handle, err)) < 0) {
printf("snd_pcm_wait error: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
first = 1;
}
}
continue;
}
size = period_size;
while (size > 0) {
frames = size;
err = snd_pcm_mmap_begin_avail(handle, &my_areas, &offset, &frames, avail);
if (err < 0) {
if ((err = xrun_recovery(handle, err)) < 0) {
printf("MMAP begin avail error: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
first = 1;
}
generate_sine(my_areas, offset, frames, &phase);
err = snd_pcm_mmap_commit(handle, offset, frames);
if (err < 0) {
if ((err = xrun_recovery(handle, err)) < 0) {
printf("MMAP commit error: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
first = 1;
}
size -= frames;
}
}
}