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Added snd_pcm_hwptr() and enhanced snd_pcm_mmap_begin() for no xrun mode.

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Jaroslav Kysela 2003-02-22 10:19:53 +00:00
parent a91efc0fe6
commit fbd99fdec0
17 changed files with 231 additions and 13 deletions
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43
src/pcm/pcm.c
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@ -868,6 +868,30 @@ int snd_pcm_hwsync(snd_pcm_t *pcm)
return pcm->fast_ops->hwsync(pcm->fast_op_arg);
}
/**
* \brief Return hardware pointer
* \param pcm PCM handle
* \return 0 on success otherwise a negative error code
*
* The hardware pointer is in range 0 ... (boundary - 1). It contains
* count_of_ring_buffer_crosses * buffer_size + offset in the ring buffer.
*
* Note this function does not return the real hardware pointer.
* The function \link ::snd_pcm_hwsync \endlink have to be called
* before to obtain the real hardware position.
*/
#ifndef DOXYGEN
int INTERNAL(snd_pcm_hwptr)(snd_pcm_t *pcm, snd_pcm_uframes_t *hwptr)
#else
int snd_pcm_hwptr(snd_pcm_t *pcm, snd_pcm_uframes_t *hwptr)
#endif
{
assert(pcm);
assert(pcm->setup);
return pcm->fast_ops->hwptr(pcm->fast_op_arg, hwptr);
}
default_symbol_version(__snd_pcm_hwptr, snd_pcm_hwptr, ALSA_0.9.0rc8);
/**
* \brief Obtain delay for a running PCM handle
* \param pcm PCM handle
@ -5792,7 +5816,7 @@ void snd_pcm_info_set_stream(snd_pcm_info_t *obj, snd_pcm_stream_t val)
* \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 offset mmap area offset in area steps (== frames) (wanted on entry (see note), returned on exit)
* \param frames mmap area portion size in frames (wanted on entry, contiguous available on exit)
* \return 0 on success otherwise a negative error code
*
@ -5805,6 +5829,9 @@ void snd_pcm_info_set_stream(snd_pcm_info_t *obj, snd_pcm_stream_t val)
*
* See the snd_pcm_mmap_commit() function to finish the frame processing in
* the direct areas.
*
* Note: The offset value is always overriden when stop_threshold < boundary.
* Otherwise, the application must specify it's own offset value.
*
*/
int snd_pcm_mmap_begin(snd_pcm_t *pcm,
@ -5817,12 +5844,18 @@ int snd_pcm_mmap_begin(snd_pcm_t *pcm,
snd_pcm_uframes_t avail;
assert(pcm && areas && offset && frames);
*areas = snd_pcm_mmap_areas(pcm);
*offset = *pcm->appl.ptr % pcm->buffer_size;
if (pcm->stop_threshold < pcm->boundary) {
*offset = *pcm->appl.ptr % pcm->buffer_size;
avail = snd_pcm_mmap_avail(pcm);
if (avail > pcm->buffer_size)
avail = pcm->buffer_size;
} else {
if (*offset >= pcm->buffer_size)
return -EINVAL;
avail = pcm->buffer_size;
}
cont = pcm->buffer_size - *offset;
f = *frames;
avail = snd_pcm_mmap_avail(pcm);
if (avail > pcm->buffer_size)
avail = pcm->buffer_size;
if (f > avail)
f = avail;
if (f > cont)