[FFmpeg-devel] [FFmpeg-cvslog] fftools/ffmpeg: add loopback decoding

[Anton Khirnov]

Quoting Gyan Doshi (2024-03-13 08:49:52)
> 
> 
> On 2024-03-13 12:57 pm, Anton Khirnov wrote:
> > ffmpeg | branch: master | Anton Khirnov<anton at khirnov.net>  | Mon Feb 19 10:27:44 2024 +0100| [a9193f7b7d65aafa326e25571c6672636a8ee3d2] | committer: Anton Khirnov
> >
> > fftools/ffmpeg: add loopback decoding
> ...
> > +E.g. the following example:
> > +
> > + at example
> > +ffmpeg -i INPUT                                        \
> > +  -map 0:v:0 -c:v libx264 -crf 45 -f null -            \
> > +  -dec 0:0 -filter_complex '[0:v][dec:0]hstack[stack]' \
> > +  -map '[stack]' -c:v ffv1 OUTPUT
> 
> Can you add an example showing the assignment of a specific decoder 
> along with a lavc generic + private option to a loopbacked stream?

Sent a patch with some notes on this.

> Are there any limitations to loopback decoding e.g. would a vpx w/alpha 
> encode be decoded back to a alpha pix fmt?

I don't know how vpx alpha works, was it a separate stream in the
demuxer or something like that?

Loopback decoders work exactly like normal decoders, except their
packets arrive from an encoder instead of a demuxer.

-- 
Anton Khirnov