/**
* \brief Read interleaved frames from a PCM using direct buffer (mmap)
* \param pcm PCM handle
* \param buffer frames containing buffer
* \param size frames to be written
* \return a positive number of frames actually read otherwise a
* negative error code
* \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
* \retval -EPIPE an overrun occurred
* \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
*
* If the blocking behaviour was selected, then routine waits until
* all requested bytes are filled. The count of bytes can be less only
* if a signal or underrun occurred.
*
* If the non-blocking behaviour is selected, then routine doesn't wait at all.
*/
snd_pcm_sframes_t snd_pcm_mmap_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t size)
{
snd_pcm_channel_area_t areas[pcm->channels];
snd_pcm_areas_from_buf(pcm, areas, buffer);
return snd_pcm_read_areas(pcm, areas, 0, size,
snd_pcm_mmap_read_areas);
}
/**
* \brief Write interleaved frames to a PCM using direct buffer (mmap)
* \param pcm PCM handle
* \param buffer frames containing buffer
* \param size frames to be written
* \return a positive number of frames actually written otherwise a
* negative error code
* \retval -EBADFD PCM is not in the right state (#SND_PCM_STATE_PREPARED or #SND_PCM_STATE_RUNNING)
* \retval -EPIPE an underrun occurred
* \retval -ESTRPIPE a suspend event occurred (stream is suspended and waiting for an application recovery)
*
* If the blocking behaviour is selected, then routine waits until
* all requested bytes are played or put to the playback ring buffer.
* The count of bytes can be less only if a signal or underrun occurred.
*
* If the non-blocking behaviour is selected, then routine doesn't wait at all.
*/
snd_pcm_sframes_t snd_pcm_mmap_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_uframes_t size)
{
snd_pcm_channel_area_t areas[pcm->channels];
snd_pcm_areas_from_buf(pcm, areas, (void*)buffer);
return snd_pcm_write_areas(pcm, areas, 0, size,
snd_pcm_mmap_write_areas);
}
static snd_pcm_sframes_t snd_pcm_file_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_uframes_t size)
{
snd_pcm_file_t *file = pcm->private_data;
snd_pcm_channel_area_t areas[pcm->channels];
snd_pcm_sframes_t n = snd_pcm_writei(file->gen.slave, buffer, size);
if (n > 0) {
snd_pcm_areas_from_buf(pcm, areas, (void*) buffer);
snd_pcm_file_add_frames(pcm, areas, 0, n);
}
return n;
}
static snd_pcm_sframes_t snd_pcm_ioplug_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t size)
{
if (pcm->mmap_rw)
return snd_pcm_mmap_readi(pcm, buffer, size);
else {
snd_pcm_channel_area_t areas[pcm->channels];
snd_pcm_areas_from_buf(pcm, areas, buffer);
return snd_pcm_read_areas(pcm, areas, 0, size,
ioplug_priv_transfer_areas);
}
}
static snd_pcm_sframes_t snd_pcm_file_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t size)
{
snd_pcm_file_t *file = pcm->private_data;
snd_pcm_channel_area_t areas[pcm->channels];
snd_pcm_sframes_t n;
n = snd_pcm_readi(file->gen.slave, buffer, size);
if (n <= 0)
return n;
if (file->ifd >= 0) {
n = read(file->ifd, buffer, n * pcm->frame_bits / 8);
if (n < 0)
return n;
return n * 8 / pcm->frame_bits;
}
snd_pcm_areas_from_buf(pcm, areas, buffer);
snd_pcm_file_add_frames(pcm, areas, 0, n);
return n;
}
static snd_pcm_sframes_t snd_pcm_file_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t size)
{
snd_pcm_file_t *file = pcm->private_data;
snd_pcm_channel_area_t areas[pcm->channels];
snd_pcm_sframes_t n /* , bytesn */;
if (file->ifd >= 0) {
n = /* bytesn = */ read(file->ifd, buffer, size * pcm->frame_bits / 8);
if (n > 0)
n = n * 8 / pcm->frame_bits;
/* SNDERR("DEBUG: channels = %d, sample_bits = %d, frame_bits = %d, bytes = %d, frames = %d",
pcm->channels, pcm->sample_bits, pcm->frame_bits, bytesn, n); */
} else {
n = snd_pcm_readi(file->gen.slave, buffer, size);
if (n > 0) {
snd_pcm_areas_from_buf(pcm, areas, buffer);
snd_pcm_file_add_frames(pcm, areas, 0, n);
}
}
return n;
}
