Update pcm doc strings

This is information I needed and is based on my understanding of information
from Takashi Iwai.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Mads Kiilerich 2009-11-14 13:48:25 +01:00 committed by Takashi Iwai
parent 4de76c9b06
commit f75f1da1b7

View file

@ -168,17 +168,17 @@ The PCM device is prepared for operation. Application can use
the operation.
\par SND_PCM_STATE_RUNNING
The PCM device is running. It processes the samples. The stream can
The PCM device has been started and is running. It processes the samples. The stream can
be stopped using the #snd_pcm_drop() or
#snd_pcm_drain calls.
#snd_pcm_drain() calls.
\par SND_PCM_STATE_XRUN
The PCM device reached overrun (capture) or underrun (playback).
You can use the -EPIPE return code from I/O functions
(#snd_pcm_writei(), #snd_pcm_writen(), #snd_pcm_readi(), #snd_pcm_readn())
to determine this state without checking
the actual state via #snd_pcm_state() call. You can recover from
this state with #snd_pcm_prepare(),
the actual state via #snd_pcm_state() call. It is recommended to use
the helper function #snd_pcm_recover() to recover from this state, but you can also use #snd_pcm_prepare(),
#snd_pcm_drop() or #snd_pcm_drain() calls.
\par SND_PCM_STATE_DRAINING
@ -1226,9 +1226,9 @@ use_default_symbol_version(__snd_pcm_forward, snd_pcm_forward, ALSA_0.9.0rc8);
* \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 blocking behaviour is selected and it is running, then routine waits until
* all requested frames are played or put to the playback ring buffer.
* The returned number of frames can be less only if a signal or underrun occurred.
*
* If the non-blocking behaviour is selected, then routine doesn't wait at all.
*/
@ -1258,9 +1258,9 @@ snd_pcm_sframes_t snd_pcm_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_ufr
* \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 blocking behaviour is selected and it is running, then routine waits until
* all requested frames are played or put to the playback ring buffer.
* The returned number of frames can be less only if a signal or underrun occurred.
*
* If the non-blocking behaviour is selected, then routine doesn't wait at all.
*/
@ -1290,8 +1290,8 @@ snd_pcm_sframes_t snd_pcm_writen(snd_pcm_t *pcm, void **bufs, snd_pcm_uframes_t
* \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 the blocking behaviour was selected and it is running, then routine waits until
* all requested frames are filled. The returned number of frames can be less only
* if a signal or underrun occurred.
*
* If the non-blocking behaviour is selected, then routine doesn't wait at all.
@ -1322,8 +1322,8 @@ snd_pcm_sframes_t snd_pcm_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t
* \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 the blocking behaviour was selected and it is running, then routine waits until
* all requested frames are filled. The returned number of frames can be less only
* if a signal or underrun occurred.
*
* If the non-blocking behaviour is selected, then routine doesn't wait at all.
@ -7211,6 +7211,8 @@ OBSOLETE1(snd_pcm_sw_params_get_silence_size, ALSA_0.9, ALSA_0.9.0rc4);
* \param silent do not print error reason
* \return 0 when error code was handled successfuly, otherwise a negative error code
*
* This a high-level helper function building on other functions.
*
* This functions handles -EINTR (interrupted system call),
* -EPIPE (overrun or underrun) and -ESTRPIPE (stream is suspended)
* error codes trying to prepare given stream for next I/O.