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

[Derek Buitenhuis]

On 31/03/2020 00:36, Michael Bradshaw wrote:
> The clli atom isn't in ISO/IEC 14496-12:2015 so the flag is marked as
> experimental and the clli atom is not written by default.

Would it make sense to allow it by default for QTFF only, since it is properly
defined in it? OR would that perhaps be a little confusing from a user perspective?

> The clli atom is referenced by e.g., [1][2] and is already parsed in FFmpeg
> in mov.c.
> 
> Once ISO/IEC 14496-12 standardizes the clli atom (which I assume it will?)
> then we can switch this to write the clli atom by default (if the metadata
> exists) and remove the write_clli flag.

I asked one of the authors of the AV1-ISOBMFF spec, and they said it has been
standardized in MIAF (23000-22), and should make their way back to 14496-12 in
the next edition. One idea is to allow it for AV1 by default, but, as above, it
is perhaps too confusing from a user perspective to do that.

Patch itself looks OK to me.

Aside: Is there an value in also supporting the mdcv box (in general)?

- Derek