Synchronization with CRT refresh

[Matthias Hopf]

On May 04, 05 11:40:24 -0400, Jim Gettys wrote:
> When I move the window to the projector on the second video output (in
> this case, it happens to be an nvidia running TwinView), I start getting
> video tearing, as the second RAMDAC does not run at exactly the same
> frequency as the primary (Andy Ritger says that the card I'm using only
> synchronizes the ramdac if you use the identical modelines, which is
> unfortunate, as I'm mixing a 1280x768 flatpanel with a 1024x768
> projector.
> 
> 
> There are several possible solutions here:
> 
> 1) say "it isn't our fault", and punt to the card to "do the right
> thing" with no additional information.

This won't be possible with combinations that need different refresh
rates (e.g. a CRT as display #1, and an LCD as display #2).

We still would want to have video players (and OpenGL apps! but that's a
different story) to be able to switch output tearlessly, on both
displays.

> I predict, though, that this kind of configuration is going to become
> common as projectors have become so cheap, and wobulated projectors/TV
> sets hit the markets this year (which take their resolution up to
> 1920x1024 class resolution at little additional cost over conventional

I guess you meant 1920x1080 ;)

Matthias

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