[FFmpeg-devel] [PATCH v3] lavu: add an AV_FRAME_DATA_GAMMA side data type

[Rostislav Pehlivanov]

On 6 November 2017 at 18:03, Nicolas George <george at nsup.org> wrote:

> Le sextidi 16 brumaire, an CCXXVI, Rostislav Pehlivanov a écrit :
> > Signed-off-by: Rostislav Pehlivanov <atomnuker at gmail.com>
> > ---
> >  doc/APIchanges      | 3 +++
> >  libavutil/frame.h   | 6 ++++++
> >  libavutil/version.h | 2 +-
> >  3 files changed, 10 insertions(+), 1 deletion(-)
>
> Sorry if it has come up before, but why not just add
>
>         AVRational gamma;
>
> with 0/0 meaning unspecified? It seems like a relevant information, at
> least as much as AVColor*. And overall much simpler.
>
> Regards,
>
> --
>   Nicolas George
>

Gamma info is related to mastering info so API users expect to get both
using the same API rather than look for new fields in avframe and evaluate
whether they're different on a per-frame basis.
Also, it prevents from adding more fields to avframe and making a bigger
mess.