[PD] Syncing an event with refresh rate in GEM

Thomas O Fredericks tof at danslchamp.org
Fri Oct 12 02:34:31 CEST 2007


I agree!
It would guarentee better results but would increase the chance of a cpu
lock up I think!

Tom

On 10/11/07, Roman Haefeli <reduzierer at yahoo.de> wrote:
>
> On Fri, 2007-10-12 at 01:49 +0200, Roman Haefeli wrote:
> > On Fri, 2007-10-12 at 00:48 +0200, cyrille henry wrote:
> > >
> > > Thomas O Fredericks a écrit :
> > > > "sync to vblank will sync swapping buffer with the screen frame
> rate, but
> > > > that's not the original question.
> > > > to my knowledge, there is no possibility to sync gem rendering with
> the
> > > > screen frame rate.
> > > > if you fix both at 60Hz, you can have jitter (not a lot, but some)."
> > > >
> > > > You are not technically syncing gem to the screen frame rate.
> > > yes
> > > > You are
> > > > syncing the open gl redraw to the framerate.
> > > yes
> > > >The GPU takes care of that.
> > > >
> > > i don't understand this.
> > >
> > > if you get gem to render a 60FPS, you will have 60fps based on the pd
> (cpu) clock.
> >
> > i don't know this by reading the code, but for me it would only make
> > sense to get the clock from the audio-card, nothing else. this is also
> > what i experienced, when pd was running on jackd, while jackd was
> > believing to be running at 44100Hz, while it was actually at 48000Hz.
> > all [metro]s were too fast and all pitches too high. the only objects,
> > that seems to work not with the audio-clock, that come to my mind, are
> > [cputime] and [realtime] (is that true?)
> >
> > > if you set your screen at 60fps, you will have 60fps based on the gpu.
> > > there is no way to make the cpu clock to be exactely the same speed as
> the gpu clock.
> > > so, sometime (specially with big patch), you can have desincronisation
> between this 2 clocks, even if they should be at the same speed.
> > > (there is a also a lot's of jitter in pd clock)
> >
> > what makes you think that? i 'd claim, that pd's clock is stable, unless
> > you get audio drop-outs.
>
> yo, it seems, that [gemhead] uses pd's logical time, which probably
> makes a lot of sense for many applications.
>
> but for many other applications it would be better (read: the result
> would look nicer), if [gemhead] would get it's tick from the gpu and not
> from pd/audiocard, i think.
>
> is that something that would be possible to do and might be worth a
> feature request on gem-dev?
>
> roman
>
>
>
>
>
> ___________________________________________________________
> Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de
>
>
> _______________________________________________
> PD-list at iem.at mailing list
> UNSUBSCRIBE and account-management ->
> http://lists.puredata.info/listinfo/pd-list
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20071011/829794ea/attachment.htm>


More information about the Pd-list mailing list