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I have a rather peculiar problem. I'm running Windows 7 and have an Nvidia GTX 470 GPU. When I have a video playing in one window and try to scroll in another window that overlaps the video window, the screen tears vertically right where the video window is in the background. I've tried turning v-sync on to no avail. Also, in Ubuntu 10.10, I have no issues, nor do I when playing a game in Windows.

Any suggestions?

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Have you downloaded the latest drivers? –  Sean Jun 29 '11 at 19:59
    
Yes, I have the very latest drivers. I also tried with older drivers, same issue. –  Max Jun 29 '11 at 20:39
    
I should also mention that this issue does not happen when the Aero theme is switched off. –  Max Jun 29 '11 at 20:49
    
what video player are you using? what renderer does the video player use? –  Uğur Gümüşhan Apr 5 at 21:41

2 Answers 2

Take a capture of the video with the PrtScr key and paste it into MSPaint. It works as expected (ie, it pastes the frame from the video rather than a black rectangle) right?

The reason you get the problem with Aero on, but not off, is that when Aero is on, it uses the overlay surface, so video players and such can not make use of it, and have to render the video in software, which results in various artifacts, including tearing. When you turn Aero off, the video player is able to render the video on the hardware overlay, thus avoiding those problems.

Unless you’ve got a newer (ie DX10 compatible) video card with corresponding WDDM 1.1 drivers, or a card with more than one overlay surface (do any even exist?), then you’ll have to choose, or at least turn Aero off when you want to watch a video.

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Yeah, the screen cap works as expected. But the GTX 470 is DX 11 compatible and the driver model is WDDM 1.1 according to dxdiag. –  Max Jun 30 '11 at 9:28
    
Regardless, there is only one overlay surface, and it seems that Windows 7 wants to use it and is not designed to play with other programs that want to use it. That means that you have to choose; transparent interface, or hardware-accelerated video. –  Synetech Jun 30 '11 at 21:14
    
Thank for the reply. It's a weird situation, especially since my Win7 laptop has no issues and uses a much less capable dedicated GPU. –  Max Jul 1 '11 at 13:10
    
Does your laptop use Aero? Does it have the default theme and transparency? What video player are you using on the problem system? Do you use the same video player as the one on the laptop? Make sure that hardware-acceleration / correct playback device is selected in the video player. –  Synetech Jul 2 '11 at 0:48
    
Yeah it uses Aero with the default theme an transparency. The issues I'm having occur with every media player I've tried (flash, media center, zune), each with hardware acceleration on where possible. –  Max Jul 2 '11 at 18:01

Windows won't double-buffer video output (EVR and DirectDraw) unless you have desktop composition (or DWM) enabled.

If you want to minimize tearing, enable DWM or Aero if you are using a media player which uses EVR, or any DirectX renderer.

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Do you have any citations or proof of this? You have not really stated why double buffering, or lack of, would cause a problem. As mentioned when desktop composition (Aero) is off the problem goes away. –  Mokubai Apr 5 at 20:17
    
@Mokubai my answer is perfect. blogs.msdn.com/b/greg_schechter/archive/2006/03/05/544314.aspx –  Uğur Gümüşhan Apr 5 at 21:39
    
"Perfect" is a subjective term. Many of your answers appear hastily written, show little effort with grammar and formatting, and often display claims without any form of credible evidence. You still don't say why having DWM enabled causes this tearing. Why does double buffering cause this problem? Surely double buffering should improve matters. Explanations are important and many of your answers are simply poor quality because you explain nothing at all, they are simply unqualified and unsubstantiated statements. –  Mokubai Apr 5 at 21:59
    
i dont have to explain every single term on my solution. op can google double buffer, evr, ddraw, dwm. –  Uğur Gümüşhan Apr 6 at 1:25
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You have missed the point of what I was saying again. If you read this comment he states that the problem goes away when Aero is disabled and comments on other answers state that Aero is in use, which is the opposite of what your answer is stating would be the problem. This was why I was trying to encourage you to improve your answer. The point is moot though as the question is 4 years old and the problem has likely gone away with a system upgrade. I'm done here. –  Mokubai Apr 6 at 5:44

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