[FFmpeg-devel] avformat/mxfenc: SMPTE RDD 48:2018 Amd 1:2022 (FFV1 in MXF) support

[Michael Niedermayer]

On Tue, Apr 04, 2023 at 04:57:03PM +0200, Jerome Martinez wrote:
> On 04/04/2023 16:43, Michael Niedermayer wrote:
> > On Mon, Apr 03, 2023 at 12:07:06AM +0200, Jerome Martinez wrote:
> > > On 02/04/2023 22:07, Michael Niedermayer wrote:
> > > 
> > > +        if (f->version == 4 && f->micro_version > 2) {
> > > +            av_log(f->avctx, AV_LOG_ERROR, "unsupported version 4 micro_version %d\n",
> > > +                f->micro_version);
> > > +            return AVERROR_PATCHWELCOME;
> > > +        }
> > >       }
> > >       f->ac = get_symbol(c, state, 0);
> > you do not know if the decoder will have any problem with these files
> 
> 
> But you don't don't if the decoder will have no problem, it seems safer to
> me to reject something we are not sure to support.

"each new micro-version after this first stable variant is compatible with the previous micro-version: decoders **SHOULD NOT** reject FFV1 bitstreams due to an unknown micro-version equal or above the micro-version considered as stable."


[...]
>  libavcodec/ffv1dec.c |    5 +++++
>  libavformat/mxfenc.c |    4 ++++
>  2 files changed, 9 insertions(+)
> 9b094eb0bd0888725a4a3fac925ef1fa733a48c3  0001-avcodec-ffv1dec-reject-unsupported-ffv1-versions.patch
> From dc0382709e548ef2514198bc866028066134d33e Mon Sep 17 00:00:00 2001
> From: Jerome Martinez <jerome at mediaarea.net>
> Date: Mon, 3 Apr 2023 00:04:53 +0200
> Subject: [PATCH] avcodec/ffv1dec: reject unsupported ffv1 versions
> 
> And add similar check in libavformat/mxfenc
> ---
>  libavcodec/ffv1dec.c | 5 +++++
>  libavformat/mxfenc.c | 4 ++++
>  2 files changed, 9 insertions(+)

the patch is mostly ok
iam a bit undecided if a decoder change and a muxer bugfix belong in the
same patch, so do as you prefer

thx

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

Good people do not need laws to tell them to act responsibly, while bad
people will find a way around the laws. -- Plato
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