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I'm considering going with a HTPC because the current DVI players are either way to expensive or flaky. The only one that "was" reasonable was the Samsung 931. The problem with this player is that they used the PC scaling for DVI video output (0-255) instead of the video scaling standard for DVI video output (16-237). This had the effect of basically crushing blacks and whites (basically 0% and 10% look the same and 90% and 100% look the same). Do the DVI ports on PC cards have this same issue or is there a way to correct this with software?


-tReP
 

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The DVI port on my projector is expecting levels between 16 (darkest, 0 IRE) and 237 (lightest, 100 IRE). Anything outside of that range is equated to 16 or 237 (i.e. 3 is thought of as 16). Therefore is the PC DVI port is scaling the IRE levels between 0-255 and maximum scale on the projector is 16-237 you crush the blacks and whites. All the fidelity between 0-16 and 237-255 is lost. This is why I returned the Samsung 931, couldn't handle missing what was going on movies like the Matrix, Underworld, etc.


My hope is that good DVD software has the ability to adjust how it is presenting the material to the display device, but I have to little knowledge in this area to make a call. That is why I asked you fine people who frequency visit this part of the AVS forums...


-tReP
 

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Got it! The limitation is in your projector in that it expects a CCRI601 format instead of RGB 0-255 over DVI.


For the most part you are SOL when it comes to using a computer graphics card because they were designed for digital monitors that support full range 0-255 RGB. Some newer Radeon drivers (I’ve been told) support 16-235 output when using the primary surface instead of the overlay surface for rendering DVD video. If this is true the desktop should also be at 16-235.
 

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If you use the latest drivers from nVidia and ATI with the VMR, then they will output 'video' levels over DVI and VGA.


Cliff - The desktop is still at 0-255 while the VMR will be 16-235. The good news is that if you calibrate for the video levels, you really won't notice the difference on your desktop.


Now if you have a digital display that does not allow you to adjust brightness over DVI and it is expecting PC levels, then you are SOL. :) The good news is that this is changing because DVI/HDMI is now moving into the CE video space.


Going forward, Windows will output video using video levels.


BTW - we call it StudioRGB, which has the same primaries as BT.709.
 

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I'm a little confused by this and some other recent threads. When I modify brightness, contrast, saturation and hue under "desktop colors" in the Radeon control panel, and when I modify gamma using PowerStrip, am I not influencing the VMR9 output? Are controls over VMR9 hidden to me unless I have or write an application that can modify them using the DirectX API?
 
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