Thanks for picking this up .. I think our color conversion code definitely will benefit from some audit ... But who is capable of such work? May be as project should put it on some website where libre programmers hang around? May be not for free but for some agreed amount of money?

Right now ffmpeg continues to integrate lcms2 so we better to have our colirs correct (right now I am not even sure if we dither rgba-float colormodel down to 8 bits (and our display code only handles 8 bit yet) in best possible way ...)

Also, can anyone test this little y4m output to pre-created fifo file? You create named fifo, point cingg at this file, choose ffmpeg - y4m output, start render, in terminal start ffmpeg encoder from this pipe ... And see how it handles this full/limited range setting