[Cin] Colour profiles in photo

[Andrew Randrianasulu]

https://ninedegreesbelow.com/photography/lcms2-unbounded-mode.html


It seems not all icc profiles are the same ...


I think for cin-gg it makes sense converting from biggest rgba-float (32
bit floating point value per color channel) , and for CVE from 16
bit/channel int format .... (I think back in time Adam deleted int 16
formats from Cinelerra 2.0 as opposed to cin 1.2 saying they were not as
good as true 32 fp)

I put some emphasis on opengl output because it offloads some of per-pixel
math to graphics hw, but slower sw only mode probably will work as proof of
concept.

As far as I understand you even can have colord daemon monitoring
hot-plugged output devices incl. monitors and providing associated profile
via some api (?) yet I only compiled it and newer used ...

It seems at least two display pathes needed, one for traditional 8 bit
displays and another for newer 10 bit ones. i thought because color
profiles known and used ever since 1996 or so, 8 bit output can be done
first ..

I'll try to find simpler lcms2 examples ...

Adding profile to some video container hopefully will be not very hard task
(i forgot about this patch for ffmpeg's mov muxer from 2019 i talked about
in cingg bug ...)

Input side hopefully already covered by ffmpeg.git patches (input image
format icc profile only should matter at decompressing into some pixel
array? Because further processing will alter those pixels ...or I am wrong
and input media profiles must be somewhat combined during track
compositing?)
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