[FFmpeg-devel] [PATCH 2/2] avcodec/h263dec: Avoid parsing extradata repeatedly

[Michael Niedermayer]

On Mon, Nov 21, 2022 at 07:53:53PM +0100, Michael Niedermayer wrote:
> On Mon, Nov 21, 2022 at 12:53:26PM +0100, Anton Khirnov wrote:
> > Quoting Michael Niedermayer (2022-11-18 00:14:18)
> > > Fixes: Timeout
> > > Fixes: 52329/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-4716563886637056
> > > 
> > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > > ---
> > >  libavcodec/h263dec.c   | 3 ++-
> > >  libavcodec/mpegvideo.h | 1 +
> > >  2 files changed, 3 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
> > > index 71b846ba74..4eab43d939 100644
> > > --- a/libavcodec/h263dec.c
> > > +++ b/libavcodec/h263dec.c
> > > @@ -492,11 +492,12 @@ retry:
> > >      } else if (CONFIG_MSMPEG4DEC && s->msmpeg4_version) {
> > >          ret = ff_msmpeg4_decode_picture_header(s);
> > >      } else if (CONFIG_MPEG4_DECODER && avctx->codec_id == AV_CODEC_ID_MPEG4) {
> > > -        if (s->avctx->extradata_size && s->picture_number == 0) {
> > > +        if (s->avctx->extradata_size && s->picture_number == 0 && !s->extradata_parsed) {
> > 
> > Wouldn't it make sense to get rid of the picture_number condition now?
> 
> I was thinking about droping it too. I dont know why i didnt, you are correct

will apply with the picture_number condition removed

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Opposition brings concord. Out of discord comes the fairest harmony.
-- Heraclitus
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