Videos written out of blender were not explicitly indicating the color
metadata (color range, primaries, TRC, color space). While some video
players assume BT.709, some others assume BT.601, leading to inconsistent
look.
Explicitly indicate BT.709 and limited ("mpeg") YUV range for video
codecs that are YUV based (i.e. final image is non-RGB(A)). Overall now
the code does the same as these command line ffmpeg parameters:
`-vf scale=out_color_matrix=bt709 -color_primaries 1 -color_trc 1 -colorspace 1`.
This also fixes an issue where video proxies were looking wrong within
Blender, if the source video file contained colorspace metadata.
Images in PR.
Pull Request: https://projects.blender.org/blender/blender/pulls/130021
527e33cef6