I have an HTPC (ATI HD4350) connected through HDMI.
In the ATI Control Center I can choose between different settings: YCbCr, RGB,... Wich would be the right one? I've read somewhere that ideally it should be YCbCr since HD content is encoded that way, but I'm not sure...
Also, in the TV settings I can choose between two colorspaces: Native and Auto. Wich is the right one?
YCbCr, 709 color space, 6500k color temp (or D65 white point depending how control is labled), 16-235 range, and 2.2 gamma (propper gamma depends on ambient light level, but 2.2 is the standard universal number, 2.4 if used in a dark room) are your propper settings for HD video. In some cases depending on the equipment, particularly HTPC's, it is better to use RGB instead of YCbCr.
YCbCr will be decoded to ... YCbCr. Depend on rendering path it may be converted to RGB (Full or Limited) or HDCP encoded and passed through card overlay. First for players like MPC, second for TMT, PDVD.
1) MPC, Pot, KMP - FullRGB
2) TMT, PDVD - YCbCr 4:4:4
Y′CbCr is not an absolute color space, it is a way of encoding RGB information. The actual color displayed depends on the actual RGB primaries used to display the signal. Therefore a value expressed as Y′CbCr is predictable only if standard RGB primary chromaticities are used.
But when I open a video with MPC-HC, it automatically outputs it to 16-235. I assume this is the normal behavior, right?
Nope. MPC (EVR, VMR, madVR) outputs in RGB 0-255 by default. Note your display is also RGB device by design. So, if you don't want to screw a picture with lossy RGB > YCbCr > RGB conversions, set your driver and display to RGB 0-255.
The correct behavior is: black as black, grey as grey.
Of course some sample may have less than 16-235 of DR. You can try another samples (a real movie) to compare.
Here is another important thing. Catalyst - Video: tick all "take settings from app", untick all other. Keep De-interlace on Auto. Set Dinamic Range to 0-255. Reboot and try.
I mean, in a 0-255 black bars .jpeg you see the whole range; and in the video too?
Of course. Some pics can have compressed range, and some movies too (very rare though).
Now I open a .JPEG and I see the whole range; and the video is clipped at 16-235. This way you see PC images right & videos too. Isn't this the way? I feel like I'm not understanding you...
Video decoder decodes compressed YUV 16-235 to uncompressed YUV 16-235
Video renderer (madVR) converts YUV 16-235 to RGB 0-255
Video driver just passes RGB 0-255 through (close to that)
TV takes RGB 0-255 signal and displays in full range.
And if your video is clipped at 16-235 somethere, you will see black as dark grey and white as light grey on 0-255 TV.
Ok, now we understand each other; that's exactly how I see it right now.
BTW, something weird happens to me... When I connect the PC through VGA instead of HDMI the behavior is:
Black doesn't show 0-17 but white DOESN'T show 230-234.
If I change the renderer setting to 16-235, I see 0-17 and 230-234 (only till 234, not till 255) (this way the black level is wrong and I have to adjust it through the TV, and "not video" images/webs/etc. are displayed with the incorrect level of black).