[FFmpeg-devel] [REQUEST] avcodec/scpr: revert d70276921348

[Kieran Kunhya]

On Tue, 20 Aug 2019 at 18:06, Michael Niedermayer <michael at niedermayer.cc>
wrote:

> On Tue, Aug 20, 2019 at 05:09:51PM +0100, Kieran Kunhya wrote:
> > On Tue, 20 Aug 2019 at 14:16, Carl Eugen Hoyos <ceffmpeg at gmail.com>
> wrote:
> >
> > > Am Di., 20. Aug. 2019 um 14:48 Uhr schrieb Paul B Mahol <
> onemda at gmail.com
> > > >:
> > >
> > > > I kindly ask that following commit:
> > > d702769213487923c0fb0abe4b61f4d9ebddb88b
> > >
> > > I still believe what the patch does is a very good idea and a revert
> would
> > > hurt FFmpeg.
> > >
> >
> > We should not turn CFR streams into VFR. This would not be acceptable for
> > H264 not should it be acceptable for any other codec.
>
> All MPEG & ITU codecs i remember follow this too as far as possible,
> including H264
>
> [...]
> again, we return metadata we do not return the same frame
>
> same is true for msmpeg4 and every other codec which uses metadata at AVI
> level
> that is skiped frames. The codecs are CFR at AVI level but we do not
> output CFR
>

All of these codecs contain metadata to add more frames if the decoder
requires.
Nowhere are frames which can't be decoded are dropped.



> But what is more bizare (to me at least) is that this was not a controversy
> at the time CFR was the standard and all these codecs where "new".
> Please correct me if iam wrong but the "CFR must be CFR" seems to
> originate
> from some professional broadcast people (like you).
>

This is what you would call an "ad-hominem"


> But then it seems the codecs which broadcast people use
> the fact they dont preserve CFR in this way isnt a problem and not even
> noticed
> while for codecs that broadcast has noting to do with like SCPR its a big
> issue.
> This makes no sense to me.
>

Someone decoding an SCPR file to encode to another format now has fewer
frames than before.
All done to pass a fuzzer. Simple as that.

Kieran

-- 
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
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