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

[James Almer]

On 11/8/2017 7:15 PM, Nicolas George wrote:
> L'octidi 18 brumaire, an CCXXVI, Hendrik Leppkes a écrit :
>> Gamma might sound useful of a property to have, but there is no actual
>> technical evidence to really support that. As said in an earlier mail,
>> we've gone for years without it and no-one missed it, and even now its
>> only being added for one decoder, and even there its apparently only
> 
> We went for years with a channel count and no channel layout too.
> 
>> used for obscure files ("joke images", as the author called it).
> 
> This would be an argument to not include it at all.

Probably a good idea.

Maybe just add the gamma value as a frame AVDictionary metadata entry?
If the idea is that the API user can get a single value from the PNG
image in some form, wouldn't side data and a dict metadata entry work
the same? The latter is much cleaner and easier to remove if needed.