[FFmpeg-devel] [PATCH] avformat/movenc: add write_clli flag to write clli atom

[Michael Bradshaw]

On Wed, Apr 1, 2020 at 3:34 PM James Almer <jamrial at gmail.com> wrote:
> Your patch to write the colr box by default is an example of this. You
> didn't remove the option like one would expect, but made it "official"
> and left for users the ability to disable the atom's presence. It should
> instead be removed and the box always written if the conditions you
> listed in that patch are met, much like every other box in the container.

I want to remove the write_colr flag and actually tried to in my first
patch but it broke use cases where "unspecified" is valid and
intended. If FFmpeg had a way to differentiate between "unspecified"
(enum value 2) and "unset" (no enum value) for color
primaries/trc/matrix then we could remove the write_colr flag. But the
simplest way to deal with this shortcoming was to just use the
write_colr flag.

If anyone has any bright ideas on how to differentiate between
"unspecified" and "unset" for color info, I'm open to suggestions. For
example, I've thought of adding a new enum value (e.g.,
AVCOL_PRI_UNSET = -1) but I've got mixed feelings about that.