Re: [Qemu-devel] Audio latency

[Alberich de megres <alberich2k5@gmail.com>]

On Thu, Feb 11, 2010 at 7:53 AM, malc <av1474@comtv.ru> wrote:
> On Thu, 11 Feb 2010, Alberich de megres wrote:
>
>> I'm using the alsa driver.
>> Even I tried to change some values using the export and some flags
>> that -audio-help shows, but nothing significant.
>
> Please do not top post.

Sorrry!!

>
>>
>>
>> On Thu, Feb 11, 2010 at 1:03 AM, malc <av1474@comtv.ru> wrote:
>> > On Thu, 11 Feb 2010, Alberich de megres wrote:
>> >
>> >> Hi!
>> >>
>> >> I'm running qemu on suse, and i got a very high audio latency. For
>> >> example, using windows latency is about 4s and audio gets distorted
>> >> with little cuts.
>
> How do you measure it?
With a program called dpc latency, it's for windows.

>
>> >> On the host side (suse), i changed the audio pci device latency to 99
>> >> but this only improves a little bit.
>
> As in: with setpci?
Yes. I also tired, on host, to low latency to VGA to 10.

>
>> >> Other thing i noticed is when lowering video resolution, the audio
>> >> latency gets better and better.
>
> Lowering video resolution of what? Guest, host?

Yes, it was on guest. Even for example if i change the desktop or
switch to a text terminal when things works better what suggested me
that could be something with painting the screen. But i'm not shure if
its just only a side effect of a bad launch command, or something
else.

>
>> >> I started played with source code, but i'm just a newbie on qemu.
>> >> Anyone can point some light to me please?
>> >>
>> >> thanks guys!!
>> >
>> > -audio-help is your friend, from there you can deduce (at the very least)
>> > which audio driver your qemu uses.
>> >
>
> It would also help to know which version of QEMU you run and exactly how
> you invoke it.

You're right..sorry:

qemu-kvm -cpu core2duo -smp 2 -m 1024 -hda /home/nine/imgs/hda1.img
-vga std  -usbdevice tablet
               -name t1  -net nic,macaddr=55:54:00:12:34:56 -net
tap,ifname=tap1,script=no
               -soundhw ac97

>
> --
> mailto:av1474@comtv.ru
>


Thanks!!