2010/12/13 Clemens Ladisch <clemens@xxxxxxxxxx> > louis@xxxxxxxxxxxxxxxx wrote: > > Hi everyone, I'm having some difficulty improving a full-duplex MMAP ALSA > > routine. ALSA sometimes reports more samples available for input than my > > buffer can take, or asks for more samples than I have available. Is this > > a buffer overrun/underrun? > > Yes. (And this should happen only when you've disabled stopping on > an xrun, so you've asked for it. :-) > > > If I restart the streams in the case that too > > much input is available (on the assumption that it's an xrun) it seems to > > happen at the drop of a hat and makes things worse. If I discard the > > excess input, that doesn't work well either. > > > > What is the appropriate way to deal with this situation? > > The best way would be to prevent this situation from happening, i.e., > read the captured data from the buffer before it overflows. > > (In the case of capturing, latency does _not_ depend on the buffer size, > so you should make the buffer as big as possible.) > > Refer to http://thread.gmane.org/gmane.linux.alsa.devel/66826/focus=66954 you mention that snd_pcm_forward can be used to recover from an underrun condition for playback In underrun/overrun of playback/capture , the hardware pointer is ahead of the application pointer Can snd_pcm_forward be used to recover from overrun in capture when automatic stop is disabled ? Why does Pulseaudio server request rewind at the end of underrun ? D: protocol-native.c: Requesting rewind due to *end of underrun* _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
