Re: Picture wobbling
Angus Dorbie (dorbie++at++multipass)
Mon, 8 Dec 1997 17:46:54 -0800
On Dec 8, 3:48pm, Rémi Arnaud wrote:
> Subject: Re: Picture wobbling
> Angus Dorbie wrote:
> >
> > On Dec 8, 1:32pm, Gerard R. Tyra wrote:
> > > Subject: Re: Picture wobbling
> >
> > > Okay, correct me if I am wrong
> >
> > OK, here's the correction.
> >
> > You call swapbuffers and it simply isn't going to happen until
> > everything is drawn so blocking in SW is little difefrent from
> > blocking in HW provided the transport delay of a swap call is
> > small which it is. The key question is "can I do usefull
> > gfx work after my call to swap but before HW swap", the answer
> > is no, the pipe blocks almost immediately, hence swapready isn't
> > essential.
>
> Swap Ready becomes mandatory when all the video do not come from the
> same box. It is now working fine, included in the very-soon-to-be-released
> Performer2.2 and does not have the latency that a software lock has that
> can in extreme cases make your software missing frames. It has
> the cost of a cable connecting every pipe SwapReady to each other, but
> will work in any pfPhase modes.
> Note that SwapReady is useless if you do not genlock the videos.
>
Yes, ofcourse swapready is usefull with multi host based rendering,
this is a different class of problem. With multi host based rendering
the sync can actually be achieved using ethernet assuming you are
aiming for a steady frame rate, and have few overload conditions, but
that's an exercise left to the reader, it is not without it's flaws.
Cheers,Angus.
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on Mon Aug 10 1998 - 17:56:21 PDT