[FFmpeg-devel] Add sample_aspect_ratio and frame_rate to AVCodecParserContext

[Markus Pfau]

we use av_parser to extract stream information for custom demuxers (e.g. 
live-tv broadcasts) to extract stream information the custom demuxer 
does not provide.
This is for example codec extra data / width / height for video, and 
sample rate for audio: 
https://github.com/xbmc/xbmc/blob/master/xbmc/cores/VideoPlayer/DVDDemuxers/DVDDemuxClient.cpp#L134-L182

To set up the initial display properly (even for h/w decoders where 
ffmpeg does not do the decoding, android MediaCodec for example), we 
would like to have the pixel_aspect_ratio and if possible the frame_rate.
av_parser already resolves SPS / VUI to put width / height into the 
AVCodecParserContext. from technical POV its a few lines of code to add 
the fields.

I want to start the discussion here, and if there are chances for 
implementation, I could do this.