[FFmpeg-devel] [PATCH] avcodec: add properties for lossless to AVCodecParameters

[wm4]

On Mon, 9 May 2016 15:28:11 +0200
Hendrik Leppkes <h.leppkes at gmail.com> wrote:

> On Mon, May 9, 2016 at 3:26 PM, Derek Buitenhuis
> <derek.buitenhuis at gmail.com> wrote:
> > On 5/9/2016 2:22 PM, Paul B Mahol wrote:  
> >> Once st->codec is gone, how would this lossless info be gathered back?  
> >
> > As myself and others have said above: decode a frame.  
> 
> And before people argue that avformat does this anyway today - one of
> the hopes is to make it stop doing that for many "simple" codecs where
> this is just not necessary, and say a parser could extract all the
> important information with much less overhead.

+1, that would be nice.

I think there should perhaps be a better solution to what libavformat
traditionally tried to do. On the command line, ffprobe could be used
to dump exact and detailed information about decoded frames. On the
ffmpeg.c level, it actually should decode a frame, which would solve a
bunch of problems, including those that can't be solved by the
traditional libavformat model. (Such as changing parameters due to
hardware decoding.)

av_dump_format() should be constrained to demuxer information. (Just
change its output.)