On 04/25/12 13:03, Jan Kiszka wrote: > Hi Gerd, > > I had problems with Windows LiveMeeting expecting a microphone as > input. But the HDA model only exposes a line-in port. The following hack > works for me, but I bet there is a cleaner solution. Any suggestions?
Good to know this works. /me has patches ready to go, was just waiting for testing feedback ... Pushed to git://git.kraxel.org/qemu audio.1 They do essentially the same, except that they leave the existing hda-duplex code as-is and add a new hda-micro codec instead which advertises the input as micro to the guest. > BTW, sound output quality of a Win7 guest on my Linux hosts sucks while > it's fine for a Linux guest. I vaguely recall that Windows requests a > too small DAC buffer, is that true? Is there anything one can do about > this? Yes. The buffer is ~ one page and can hold 20 ms of sound data, so considering buffer flipping intel-hda has to shuffle data every 10ms, and the windows guest needs to be scheduled too so it can re-fill the other half of the buffer. Which obviously makes sound playback *very* sensitive to latencies anywhere in the qemu. What you can do about it? Dunno whenever windows allows to tweak the buffer size somehow. When I looked deeper at that a while back the biggest latency issues in qemu used to be qxl, ide/qcow2 and vnc. qcow2 should be fixed now with the switch to coroutines and full async i/o. Likewise qxl, although this depends on recent guest drivers. For vnc enabling the threaded vnc server helps alot (without it moving around windows leads to sound dropouts). cheers, Gerd
