Originally Posted by maxleung
Every player does different things when taking the 4:2:0 source from a Blu-ray and outputting to the display. Some always output 4:4:4, after upconverting 4:2:0. In fact, it seems, after viewing some displays/players with the Spears and Munsil HD Benchmark 2nd Edition disc, that many do really odd things with the image.
Have a look at this page for the many things that can happen, even for a simple 4:2:0 output (if the player even offers that as an option - most players I've seen only do YCbCr or RGB or RGB limited options - and you have no idea if it is 4:4:4 or 4:2:2 output for YCbCr instead of 4:2:0 that you would expect for BD):
There is also chroma upscaling done by the player and/or the display to consider.
The above link has some good examples of how different devices screw up the output.
If my display and color have options for color space and deep color, I set them to do as little processing and enhancing as possible. I set my display to Auto because it matches the input source, as opposed to applying its own expansion beyond the source material. Since most Blu-ray discs are recorded at 8-bit, YCbCr4:2:0, I set my Blu-ray player to YCbCr4:2:2 (since it is the closest thing to YCbCr4:2:0), and turn Deep Color off. Then if titles are released with one of the enhanced color spaces and/or 20-bit or 36-bit deep color, I can set my player to output according to the disc I'm playing. Who knows, like some players change resolution according to the disc, maybe players will some day be able to change color space and deep color settings according to the disc as well. Then I wouldn't have to do as much manual switching every time I load a disc. I know I'm going offtopic, but it would also be cool if in addition to resolution, color space, and deep color settings, it would be convenient if the player can automaticly change aspect ratio according to a loaded disc as well to avoid stretching/squeezing so that nothing has to be manually changed every time you load a disc (if playing a disc recorded at 1920x1080, the player should be able to detect the actual aspect ratio, adding the black bars on the top and bottom if necessary, and if playing a letterbox 720x480 or 720x576 DVD, it should detect that it's letterboxed and add the black bars).