[FFmpeg-devel] [PATCH 1/2] avcodec/avpacket: Use av_copy_packet_side_data() in av_packet_copy_props()

[Hendrik Leppkes]

On Wed, May 3, 2017 at 11:50 AM, Michael Niedermayer
<michael at niedermayer.cc> wrote:
> On Wed, May 03, 2017 at 11:37:35AM +0200, wm4 wrote:
>> On Wed, 3 May 2017 11:29:04 +0200
>> Michael Niedermayer <michael at niedermayer.cc> wrote:
>>
>> > On Wed, May 03, 2017 at 05:29:07AM +0200, wm4 wrote:
>> > > On Wed,  3 May 2017 05:21:50 +0200
>> > > Michael Niedermayer <michael at niedermayer.cc> wrote:
>> > >
>> > > > Fixes timeout
>> > > > Fixes: 1293/clusterfuzz-testcase-minimized-6054752074858496
>> > > >
>> > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
>> > > > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
>> > > > ---
>> > > >  libavcodec/avpacket.c | 3 +++
>> > > >  1 file changed, 3 insertions(+)
>> > > >
>> > > > diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
>> > > > index 4bf830bb8a..ff7ee730a4 100644
>> > > > --- a/libavcodec/avpacket.c
>> > > > +++ b/libavcodec/avpacket.c
>> > > > @@ -557,6 +557,9 @@ FF_ENABLE_DEPRECATION_WARNINGS
>> > > >      dst->flags                = src->flags;
>> > > >      dst->stream_index         = src->stream_index;
>> > > >
>> > > > +    if (!dst->side_data_elems);
>> > > > +        return av_copy_packet_side_data(dst, src);
>> > > > +
>> > > >      for (i = 0; i < src->side_data_elems; i++) {
>> > > >           enum AVPacketSideDataType type = src->side_data[i].type;
>> > > >           int size          = src->side_data[i].size;
>> > >
>> > > This doesn't look right...
>> >
>> > already fixed the ; locally
>> >
>> >
>> > [...]
>>
>> I didn't see that, I was referring to the fact that you call
>> av_copy_packet_side_data(), and only sometimes (at least by intention).
>> That requires at least an explanation in the commit message.
>
> av_packet_copy_props() would add side data to the destination packet
> it doesnt replace previously existing side data except in case of
> error.
> I dont know if that is intended but i didnt want to change it as that
> would be unrelated to this patch
>

This behavior seems odd at best, so maybe we should just change that
and make the behavior more logical, and fix your issue at the same
time?

- Hendrik