[FFmpeg-user] The internal ffmpeg rgb=>yuv pipeline and conversion matrices

[Andy Furniss]

Peter Rabbitson wrote:

>            -c:v libx264 -colorspace bt709 -pix_fmt yuv444p -profile:v
> high444 \
>            -qp 0 -preset:v ultrafast \
>            -t 5 greenz.mkv

FWIW just using -colorspace is not complete.

ffmpeg -i greenz.mkv would list 709/unknown/unknown

adding

-color_primaries bt709 -color_trc bt709

removes the unknowns and for ffmpeg changes behavior in one
test case I tried = retesting making a png. Your command will
produce a different png from the mkv than one made from an
mkv made with the two extra params.

The difference is gamma meta - many viewers may ignore it anyway
- it's just an example.