[FFmpeg-devel] [PATCH] lavc/vp9: fix reference frame dimensions check

[Carl Eugen Hoyos]

Am Mi., 11. März 2020 um 13:44 Uhr schrieb Fu, Linjie <linjie.fu at intel.com>:
>
> > From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> > Carl Eugen Hoyos
> > Sent: Wednesday, March 11, 2020 18:48
> > To: FFmpeg development discussions and patches <ffmpeg-
> > devel at ffmpeg.org>
> > Subject: Re: [FFmpeg-devel] [PATCH] lavc/vp9: fix reference frame
> > dimensions check
> >
> > Am Mi., 11. März 2020 um 11:44 Uhr schrieb Linjie Fu <linjie.fu at intel.com>:
> > >
> > > With the description in frame size with refs semantics (SPEC 7.2.5),
> > > it is a requirement of bitstream conformance that for at least one
> > > reference frame has the valid dimensions.
> > >
> > > Modify the check to make sure the decoder works well in the condition
> > > that not all references frames have valid dimensions.
> > >
> > > Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> > > ---
> > > Fix the the decoding faiure for frames with dimension-ilegal refs.
> > > Verifying with native vp9 and libvpx-vp9 decoder, the md5 result matches.
> > >
> > https://github.com/webmproject/libvpx/blob/master/vp9/decoder/vp9_de
> > codeframe.c#L1580
> >
> > Did you provide a sample?
> >
> I'd like to, but to be honest, it seems kind of hard to produce such a stream available
> for public (compared with setting TU depth for one frame), hence I could not promise
> but will try. (any hints for this?)
>
> To elaborate more, one of the failure case is a 480x272 inter frame with two refs:
> Ref[0]: 1920x1088 key frame, invalid;
> Ref[1]:  960x 544 inter frame, valid;
>
> Which reports:
> [vp9 @ 0x55b18d9be280] Invalid ref frame dimensions 1920x1088 for frame size 480x272

This should be even more part of the commit message if you cannot
provide a sample.

Carl Eugen