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So, after having seen the impressive increase in quality running DVDs through a PC vs. my $50 DVD player and needing a new computer, I decided to build my own HTPC. Everything works great except for one thing that I've been calling "tearing" but I am not sure if it is the same tearing that everyone else here is talking about. There are tons of threads on how to fix it, but none on what it is (so far as I can tell - a search for "What is tearing" doesn't bring up much useful).


I made a little GIF showing the "tearing" I am seeing. Can someone verify that this is tearing?




I've got everything running through my benQ 6200 projector. I've also got a splitter on the VGA cable running everything to an old monitor. The picture looks great on the monitor; the "tearing" only happens on the projector. I've removed every piece of equipment between the computer and the projector and it still happens. Using the "JudderTest" program also shows this "tearing." Does that mean it is called "judder" as well?
 

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Discussion Starter #3
Thanks :)


I actually have both of those in action, but reclock keeps telling me it doesn't work with my graphics card (nVidia 6600 PCIe).


If nothing else, at least knowing what I am seeing is tearing lets me do some research on it. I think it has something to do with the refresh rate of my projector vs what MCE is pumping out.


Time to go experiment. Thanks for the quick answer Cush.


Nate
 

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I believe there are really three kinds of 'tearing' and they get mixed up. The first is a ground loop rolling bar type, which looks very much like your gif animation. Probably why they get mixed up! It should be noticed even on static images, where the other two are more pronounced on moving images.


The second is caused by software writing to internal display buffers that happen to be on screen. This one is noticed only on moving images and is the one most people refer to as tearing. Changing the video renderer type should fix it, or at least change the behavior of the tear.


The third kind has to do with two systems, the video card and projector, running asynchronously to each other. (Note: This is my best guess, because I too couldn’t find much on the web.)


At first, one would think the projector would use the sync signals directly from the video card. However, the projector needs to function without an input signal, so you can access menus for configuration and selection of inputs among others. To incorporate this feature it needs it own video circuitry, which includes video timing that is probably unique to the imaging device (LCD/LCOS/DLP). Try changing your vertical refresh, maybe using powerstrip and judder test, to verify that the tearing period changes. If it does change the frequency of tearing, this might be the culprit. For now, I suggest you pick a refresh rate that is least intrusive.


I have spent a lot of time on this one and would appreciate any other ideas!


Raymond
 

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Tearing is simply the video card frame buffer's inability to draw the image correctly hence the frame is not aligned.

If you game, you will have to turn vertical sync on. This limits the frame rate to the refresh rate.


For video, Nvidia 6 and 7 series cards have this issue including stuttering.

The only fix is to run it in Exclusive Full Screen Renderless mode. It works just like D3D games where the renderer occupies the whole PC. No multitasking.

A few players support renderless like TT2.1 and ZP4.51. MCE supports renderless.


If you have already tried full screen renderless and it still tears, you may have a problem w/ your video card and/or drivers.
 

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Put yet another way and as implied by the others, there are two video buffers that can have tearing - one on your graphics card and one in your display device. The first is fixed by using a faster renderer, the best being VMR9 Renderless in Exclusive Fullscreen mode (ZoomPlayer: Options > Filter Control > Settings). The second can hopefully be fixed by finding a sweet spot refresh rate. JudderTest can help you find this.


Judder/stutter is something else. It is caused by frame rate conversions either on the PC side or in the display device. It can be seen in panning scenes or the credits as a small jerkiness. To fix this your refresh rate must be a multiple of your source material frame rate.
 

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Discussion Starter #7
I don't think I see Judder, but that might just be because I am too obsessed with the tearing.


If you do have judder, do you have to adjust the frame rate for every different media type you play (TV vs DVD)?


Since my CRT looks great (with no tearing or judder that I can tell) and my DLP projector does not, I am fairly certain it is a frame rate issue for the projector. Unfortunately, I use MCE and haven't been able to find a way to get it to not switch to 60Hz when launching full screen.


Before I had this PC installed, I used component out on my DVD player and it never juddered or tore. Now, the picture looks 100x better than before, but I've introduce these new problems. Why doesn't the standalone DVD player produce these problems?


Thanks for all of your help. I think I've got a good handle on what the problem is. Now I've just gotta keep reading...


Nate
 
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