Re: [Qemu-devel] Audio latency

[malc]

On Thu, 11 Feb 2010, Alberich de megres wrote:

> On Thu, Feb 11, 2010 at 10:45 PM, malc <address@hidden> wrote:
> > On Thu, 11 Feb 2010, Alberich de megres wrote:
> >
> >> Another interesting thing:
> >>
> >> on guest side,
> >> when i leave the screen quiet, for example just showing desktop with
> >> no animations at all (so there's no change in what should be drawed)
> >> things improve a lot of, and then i coudl hear a song perfectly.
> >> The screen is 1680x1050. the same thing happens when i low screen
> >> resolution to 800x600
> >>
> >> Could be the emulated VGA graphic adapter latency? I suppose that i
> >> haven't 2D acceleration so CPU has to paint the screen everytime a
> >> change is done.
> >>
> >>
> >> On Thu, Feb 11, 2010 at 7:07 PM, Alberich de megres
> >> <address@hidden> wrote:
> >> > On Thu, Feb 11, 2010 at 8:42 AM, malc <address@hidden> wrote:
> >> >> On Thu, 11 Feb 2010, Alberich de megres wrote:
> >> >>
> >> >>> On Thu, Feb 11, 2010 at 7:53 AM, malc <address@hidden> 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!!
> >
> > And there you go again :)
> >
> :( sorry once again
> 
> > [..snip..]
> >
> > QEMU is synchronous, if it takes too much time doing the video stuff
> > audio will be starved, i don't think i can help with that, what you
> > can do to test this theory of yours is to use VNC, set things up start
> > the song and then disconnect, if the audio is playing normally then
> > you are right.
> >
> You mean VNC conecting to guest OS? (windows in this case?)

No i mean QEMU's builtin vnc server:

I.e. n one terminal:

$ qemu [..args..] -vnc :0

And elsehwere:

$ vncclient localhost:0

> 
> Qemu, uses some kind of 2D hardware acceleration to draw? or simply it
> does with CPU?

Almost none with std-vga, btw you can also try -vga vmware

> 
> It would be hard for me to implement a patch to make qemu
> asynchronous? (i mean, if the qemu soft architecture allows it on a
> easy way or not).

Yes, it would be hard for you, for anyone even.

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