It seem that the difference between the application pointer and the hardware pointer is just the theoretical value which none of the sound card can achieve static snd_pcm_sframes_t snd_pcm_hw_rewindable(snd_pcm_t *pcm) { return snd_pcm_mmap_hw_avail(pcm); } To allow the application rewind the application pointer to hardware pointer and rewrite the next sample immediately at any time The audio controller have to fetch the audio data as the same rate as the sampling rate. The practical value may be the difference between the application pointer and the nearest period boundary 2009/9/24 Takashi Iwai <tiwai@xxxxxxx> > At Thu, 24 Sep 2009 13:04:24 +0530, > Anuj Aggarwal wrote: > > > > Hi, > > > > I want to try the forward/rewind APIs supported by the ALSA library. > > Can someone point to an ALSA application which exercises these APIs? > > Pulseaudio is using snd_pcm_rewind(). > About snd_pcm_forward(), I don't know of... > > > Takashi > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel