On Wed, Nov 10, 2010 at 12:37:04PM +0100, Gerd Hoffmann wrote: > On 11/10/10 11:36, Daniel P. Berrange wrote: > >On Wed, Nov 10, 2010 at 10:48:39AM +0100, Gerd Hoffmann wrote: > >>The qemu vnc server has support already, and I think Daniel (added to > >>Cc:) has some experimental patches for the gtk-vnc widget. > > > >Yes I do have patches, but I'm yet to get it to work reliably enough for > >anyone to use for real. eg any time there are large frambuffer updates > >due to, say, dragging a window around, audio will drop out. Until I can > >prove that it is even semi-reliable I'm not going to include the code in > >gtk-vnc, because I don't want to commit to supporting something that may > >well be fundamentally broken/unusable for live audio playback. > > Do you know where the dropouts come from?
Not entirely, it is still rather work in progress to debug it. Part of the issues is that even QEMU + one of the standard pulseaudio/alsa/sdl audio backends doesn't seem very reliable to me, so I've not got a reliable benchmark to compare VNC audio against. Just testing with mpg123 in the guest, audio will often simply stop after a few seconds of playback to the host. > I think one issue are latencies within qemu. The qemu vnc server is > busy for a while when doing bulky screen updates and blocks other stuff > while it runs. I've seen dropouts with vnc + bulky screen updates too. > The smaller the audio buffers used by the device/guest are the more > visible this effect is. When enabling the threaded vnc server this > becomes alot better, did you try that? It looks like the threaded server is disabled by default, so I've not been using it thus far. I'll give it a try though. Is there a particular audio device that is considered to work 'best' ? I've been using ac97 mostly, but if your new ICH6 device is thought to be significantly better I'll try that instead. Regards, Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|
