Performer Mailing List (perflist++at++vr.mme.wsu.edu)
Wed, 10 Dec 1997 22:41:25 -0800
I have tried several different methods of locking the frames but have
been unable to get rid of the wobble. When I genlock the two pipes
(using Pipe 0 as master with Internal Sync and Pipe 1 as slave with
external sync and both set to Horizontal sync only), the gfxinfo tells
me that pipe 0 is set to internal sync and is not genlocked while pipe 1
is genlocked. However, whenever I get pipe 1 genlocked, the video
format seems to cause problems for the VR4. I have tried setting the
VR4 to sync on green and also to separate sync sending the horizontal
sync from each pipe to the two screens of the VR4.
Any suggestions?
Is anyone out there with a VR4 HMD and a two pipe IR that has a
successful implementation????
Thanks in advance
Jay
Angus Dorbie wrote:
>
> 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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