Originally Posted by praktik
oh headlesschickens - i absolutely need to do the registry tweak, even under win 7? I've seen that mentioned but was hoping my Nvidia driver setting would be enough from their control panel...
Are you referring to the setting under "Adjust Video Color Settings" -> "Advanced" ? That setting only applies to video software color conversion (in fact that's how you change the setting I kept saying would be in the video player software itself these days, whoops). I did make one error though, which is that I believe this is actually an NVidia thing, not Windows. So if you have an NV card then you do need the registry tweak. I don't know what options AMD cards have for this. NV drivers will put HDMI devices in 16-235 mode and all others into 0-255 by default, so you do need the registry tweak to sort this all out.
Originally Posted by headlesschickens
The card isn't expanding the color data itself. Think about what that would imply: If you put up a dark grey image on the desktop of values (r16,g16,b16) in 0-255 range it would make it black on a normal PC monitor (0-255) if it did this. It's your video playback software that's doing it; it's automatically converting your video to the mode the video card is currently set to because for most users that's what makes sense. For example, iTunes does this with no option to turn if off because otherwise literally ever movie or TV show played through it on a normal PC monitor would have grey blacks and grey whites. A good piece of software should have an option to disable any color conversion.
Okay, I sort of half got this wrong. The default setting of "Adjust Video Color Settings" -> "Advanced" is to let the video player decide, but it seems like instead of trying to hunt for this setting in your player software (and it may not exist), it's easier to just select "With the NVIDIA settings" and set it to "Limited (16-235)." I realize that's confusing since I just said you want the video output in Full, but this is only the setting for video rendering at the software level. By selecting "Limited" you'll stop video playback from doing the conversion even if the software doesn't have such a setting. It should work with most video players, except iTunes which, being from Apple, decides to play by its own rules. Definitely worked with VLC, which is the most advanced player I have since I don't have a BR drive in my system.
Sorry if this is turning confusing, I'll try to sum it up a bit.
-Get your PC outputting 0-255 mode. To make sure it's working, put your TV in 0-255 range and then put up a black image on your desktop. If it's real black, you're good. If it's dark grey, you'll need the registry tweak.
-Make the setting change I mentioned above. NV Control Panel -> Video -> Adjust Video Color Settings -> With the NVIDIA settings -> Advanced -> Limited (16-235). This will only impact video processing, not video card output.
-Make sure any intermediate devices between the PC and the TV are set to input and output 0-255 without doing conversions.
-Set your TV back to 16-235 mode when you want to watch a video. Leave it in 0-255 mode when you want to play a game or just have accurate colors for general PC stuff.
-Don't use iTunes because it won't respect your video conversion settings (someone might have a hack for solving that, but I'm not aware of it).
Originally Posted by rahzel
I deleted the post you quoted and re-worded it better.
What I meant was that when you select YCbCr or 16-235 RGB output on a PC, it will internally get converted to RGB 0-255 regardless because that's what all GPUs render everything at natively. If you select 16-235, levels get compressed back to 16-235. That's why I recommend outputting RGB 0-255 from PCs (if your display is capable of accepting this range that is), to avoid any unnecessary conversions. Most GPUs do a low quality YCbCr to RGB conversion that usually causes a lot of banding; madVR does this in much higher precision and it is pretty much the quality standard in the HTPC world for video renderers.
Yes by outputting 0-255 you lose BTB/WTW information, but this is not valid video information anyway. Anything below 16 is meant to be black/not visible and anything above 235 are usually just ringing artifacts.
Again, I highly recommend reading the thread I linked to in my above post regarding 16-235 vs 0-255 for PCs.
You do not lose BTB/WTW information unless the video software is stripping it. And it might, I don't actually know. Just saying that when the video player is set to 16-235 mode and the PC is set to 0-255, the BTB/WTW info should theoretically still be in there unless the software is throwing it out. You won't actually see it if your TV is set to 16-235 and calibrated right, but then that's kind of the point to begin with - maximum possible range between black and white.