[FFmpeg-devel] [PATCH] libavcodec/h261dec: Fix keyframe markup and frame skipping.

[Michael Niedermayer]

On Tue, Oct 29, 2019 at 04:39:16PM +0300, Andrey Semashev wrote:
> On 2019-10-26 14:05, Andrey Semashev wrote:
> >The decoder never marks pictures as I-frames, which results in no
> >keyframe indication and incorrect frame skipping, in cases when
> >keyframes should be decoded.
> >
> >This commit works around this decoder limitation and marks I-frames
> >and keyframes based on "freeze picture release" bit in h261 picture
> >header. This reflects h261enc behavior.
> 
> So, is this patch acceptable? If yes, could someone merge it please?

The patch does 2 things

1. it skips !freeze_picture_release frames if the user wants non key frames 
    skiped

that seems reasonable


2. it marks freeze_picture_release frames as key/intra frames

i do not know if this is a good idea as i do not know if every
encoder sets this on key frames. Our encoder is not every encoder

If the patch intstead would set the flag depending on the blocks
then i would apply it

otherwise it would be nice to see a bit more evidence that this
flag is really always set for keyframes by most encoders.
Or maybe someone "knows" this then it can be applied too.

So I cant awnser if the patch is acceptable as is as i do not
know from the information provided how widely this flag is set
on keyframes

thanks

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Rewriting code that is poorly written but fully understood is good.
Rewriting code that one doesnt understand is a sign that one is less smart
then the original author, trying to rewrite it will not make it better.
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