qtdemux: Inconsitent handling of UNKNOWN colorimetry field
I'm a bit puzzled, I've hit a use case where some colorimetry field are 0 and lead to negotiation failure with v4l2h264dec (something also a bit broken in v4l2h264dec, I can admit). Now, looking at qtdemux first, I notice that handling of "UNKNOWN" field is inconsistent. For VP9, we ignore anything that would have unkown, but for
colr we don't.
I'm filling an issue to understand which way is right, of course for me the VP9 way would fix stuff, but I want to get the rationales before sending patches.