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Old 05-04-11, 02:58 AM   #369
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Join Date: Sep 2006
Posts: 11
Default Re: VDPAU testing tool

To the people claiming that 60 fps should be 'enough', I disagree. For example, what if the performance degradation is caused by a small handful of the frames taking longer than 1/60th of a second to render? Result is you get a 'stuttering' effect in the video.

I've made a video that alternates full frames of black and white at 30 fps, and I can clearly see some 'stuttering' in the video playback (video is attached if you want to try it out yourself). (Note: The flashing effect in the video is somewhat intense, so don't view it if you think it could be dangerous to your health)

I have a GTX 460, Q6600 CPU, Ubuntu 11.04, latest SVN of mplayer, 270.41.06 driver. I also saw this in the 260 series drivers with earlier versions of Ubuntu.

This video is also a good test for tearing. I can clearly see tearing (sometimes I need to play the video a few times to see it).

Obviously something is broken in VDPAU (or at a lower level) on this class of card.

If I use -vo xv or -vo gl_nosw instead of vdpau, I see no tearing, and there is less 'stuttering' too. I thought vdpau was supposed to be superior to these other output methods? In some cases there is severe tearing with vdpau. I wouldn't classify this performance as 'best effort' (it's more like a 'lousy effort').

Can you get an nVidia engineer to grab the video here and a 400-series card and try it out?

I also see the same poor performance in the mixer under qvdpautest as the other posters.
Attached Files
File Type: gz teartest.tar.gz (1.8 KB, 122 views)
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