Originally Posted by sotti
I somewhat disagree. Obviously we can encode steps all the way to 254(5) for RGB in YCbCr, how else would we generate the ramps?
But even though 16-235 are the only valid values for white, the chroma channels are valid through 240
Please note that I'm using your response as a bit of a springboard.
First: as I quoted CbCr is 16-240 (my emphasis).
The digital representation shall be as defined in Part 1, Section 6.10 of ITU-R BT.709-5 and is summarized below:
The coding shall be 8-bit coding (scale of 0 to 255). R, G, B, and Y signals shall have 220 quantization levels with the black level corresponding to level 16 and the peak white level corresponding to level 235. The signal level may occasionally move beyond level 235. CBCR signals shall have 225 quantization levels with a zero level corresponding to digital level 128 and full range corresponding with 16 to 240. For R, G, B, Y, CB, CR signals, 0 and 255 are reserved and should not be considered video.
I don't choose to argue about or care much about technical minutia. I don't even care much what happens in post. I have no control over that. What I care about is what my equipment can do. And like any number of other bits of AV stuff it clips outside the STANDARD
range. Yes, that's right, CEA-861-D is a standard followed by consumer electronics manufacturers world-wide. So my wonderful 9g Kuro monitor clips because Pioneer read the standard (it also obeys the quantization flags in 861/HDMI 1.3, possibly the only display to do so). My AVR used to clip (because you can program a REON to clip) until I convinced them it was a good thing not to clip.
All the obstruse technical arguments in the world are irrelevant unless they take operation standards into account.
Said standards are the reason for this and various other threads asking about "Setting contrast with Spears and Munsil disc" or any other reference material.
On the bright side these things can actuall be fixed (just join CEA) -- unlike all the crappy DVDs you own with bogus MPEG flagging and horked telecine.