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Old 05-07-09, 12:39 PM   #1
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Join Date: May 2008
Posts: 113
Default SDLMAME OpenGL vsync problem

These are my current specs:
7600GS card
177.xx nvidia driver
Ubuntu Intrepid
LCD flat panel on DVI output
Analog television on S-Video output
Twinview, one giant spanning screen mode
Composite disabled in xorg.conf

I seem to have a problem with obtaining tear-less video in SDLMAME. It doesn't matter what sync options I select or deselect in the nvidia-settings utility. All of my SDLMAME games have a moving tear line in them. This is more pronounced on side-scrolling games of course. It happens in windowed and fullscreen modes.

I don't have problems with other OpenGL apps such as games or MythTV in windowed mode using OpenGL rendering. These programs sync very smooth without tearing.

I've put in a question to the SDLMAME fourm about this, but received no response. There doesn't seem to be much complaining about it from other SDLMAME users, so I have to assume either I'm the only one having the problem or everyone else just accepts it as normal.

Is this a problem with my use of an older nvidia driver? Would I see any difference by upgrading my card or driver? Does it have something to do with Twinview? I don't understand what the difference is between SDLMAME's OpenGL rendering and MythTV's rendering or (put your favorite Linux game here) rendering.

For example, many SDLMAME roms run at NTSC frame rates yet for some reason I have a tear line in them. I also see the same tear line from games that don't run at tight NTSC frame rates, like 54 Hz or whatever. MythTV's output is NTSC of course, and it is smooth even on my LCD flat panel which does not adhere to NTSC timing either. According to the nvidia-settings util my LCD runs at 60.042 Hz or something like that.

So what are the differences, and is there any way to get smooth video out of SDLMAME?

mocharhw is offline   Reply With Quote