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Old 19th August 2019, 15:55   #103  |  Link
poisondeathray
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Join Date: Sep 2007
Posts: 5,346
Quote:
Originally Posted by StvG View Post
zimg uses those values from wikipedia - https://github.com/sekrit-twc/zimg/b...ce_param.h#L28 REC_470_BG (625 lines) and SMPTE_C (525 lines/170m/240m).
My bad; I got confused by hello_hello's chart reproduction . The headings are shifted in his post

They are aligned here
https://en.wikipedia.org/wiki/Rec._6...chromaticities

And they match the ITU HEVC document and wikipedia, so false alarm




Quote:
Originally Posted by jpsdr View Post
Quote:
Originally Posted by poisondeathray View Post

In practice, only matrix is usually accounted for, not primaries. You see this in professional HD to SD conversions, broadcast NLE's too . Technically you should adjust for the primaries too, but it's rarely done.
Unfortunately, this is not helping the mess.



Primaries aren't usually adjusted for in the 709/601 case, or you get shifted colors . The underlying premise is you should get the same colors in HD as SD when viewing

I verified this with a bunch of things, software players, NLE's, professional tools, hardware players - DVD, BD, both authored discs connected to TV , and as files, devices phones, set top media players . Also retail discs (BD and the DVD from the same studio; the same "movie" but released by different studio can have different colors), and TV broadcasts . It's entirely possible that I messed up some observations or made a mistake somewhere, but the findings are 99.9% consistent - really only the matrix is used in practice.

Note I didn't check 2020 or UHD equipment for this - it has to be rechecked
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