From 7fe18c95619ce8c425b3bcaf5448fded6fe1f788 Mon Sep 17 00:00:00 2001 From: Jaroslav Kysela Date: Wed, 4 Dec 2002 15:34:04 +0000 Subject: [PATCH] Added more comments by Robert Spier (robrt@users.sourceforge.net) --- src/pcm/pcm.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c index 6fb8a196..dbcf5ffc 100644 --- a/src/pcm/pcm.c +++ b/src/pcm/pcm.c @@ -104,8 +104,8 @@ implementation can be found in the \ref alsa_pcm_rw section. The poll or select functions (see 'man 2 poll' or 'man 2 select' for further details) allows to receive requests/events from the device while an application is waiting on events from other sources (like keyboard, screen, -network etc.), too. The select function is old and deprecated in modern -applications, so the ALSA library does not support it. The implemented +network etc.), too. \ref snd_pcm_poll_descriptors can be used to get a file +descriptor to poll or select on. The implemented transfer routines can be found in the \ref alsa_transfers section. \subsection pcm_transfer_async Asynchronous notification @@ -5157,6 +5157,15 @@ int snd_pcm_sw_params_get_sleep_min(const snd_pcm_sw_params_t *params, unsigned * \param params Software configuration container * \param val Minimum avail frames to consider PCM ready * \return 0 otherwise a negative error code + * + * Note: This is similar to setting an OSS wakeup point. The valid + * values for 'val' are determined by the specific hardware. Most PC + * sound cards can only accept power of 2 frame counts (i.e. 512, + * 1024, 2048). You cannot use this as a high resolution timer - it + * is limited to how often the sound card hardware raises an + * interrupt. Note that you can greatly improve the reponses using + * \ref snd_pcm_sw_params_set_sleep_min where another timing source + * is used. */ #ifndef DOXYGEN int snd_pcm_sw_params_set_avail_min(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_sw_params_t *params, snd_pcm_uframes_t val) -- 2.11.0