[FFmpeg-devel] [PATCH 2/3] libavcodec: v4l2m2m: output AVDRMFrameDescriptor

[Jorge Ramirez-Ortiz]

On 05/10/2018 04:47 PM, wm4 wrote:
>> so what would be the sequence of calls for an libavcodec client to
>> request the DRM format?
>> https://github.com/BayLibre/ffmpeg-drm/blob/master/main.c#L598
> Like in 100% of all existing cases in ffmpeg: set a get_format
> callback, and return the format from it.

Sure, but it is seems like a bit of a unortodox solution to what in 
principle seems like a simple problem of passing a list of valid 
formats; a solution that allows clients to sneak in all sort of 
additional actions and just confuse the code.

Just looking at doc/examples/qsvdec.c, get_format not only returns the 
format but also allocates hw frames; so it seems like single 
responsibilities are not necessarily associated to this callback then 
(ie, get_format is not only about getting formats is it?).