snd_pcm_playback_data(9) suse man page | unix.com

SND_PCM_PLAYBACK_DAT(9) 					   Sound Devices					   SND_PCM_PLAYBACK_DAT(9)

NAME
       snd_pcm_playback_data - check whether any data exists on the playback buffer

SYNOPSIS
       int snd_pcm_playback_data(struct snd_pcm_substream * substream);

ARGUMENTS
       substream
	   the pcm substream instance

DESCRIPTION
       Checks whether any data exists on the playback buffer. If stop_threshold is bigger or equal to boundary, then this function returns always
       non-zero.

       Returns non-zero if exists, or zero if not.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010						   SND_PCM_PLAYBACK_DAT(9)