On Fri, Nov 4, 2016 at 12:55 PM, Gerd Hoffmann <kra...@redhat.com> wrote: >> > I think the QEMU ALSA sound driver should not be monitoring the >> > playback file descriptor if the emulated sound card decides it needs >> > to wait for the guest. > > I think it should never monitor the file descriptor. > >> > Should we add an AUD_plug_out()/AUD_unplug_out() interface to the QEMU >> > audio subsystem so soundcards can suspend file descriptor monitoring? > > spiceaudio has a rate control which calculates the number of audio > samples based on time. That works pretty well and I think it is the > best way to handle it. The other audio drivers do the same. > > Trying to keep the alsa audio buffers full (by watching the playback > file handle) does not only cause problems in case the guest hasn't > enough audio data to fill them, it also increases the latency in the > audio playback pipeline.
Okay, then the ALSA backend needs to be changed. Thanks for explaining. I probably won't have time to look into this issue. Stefan
