[FFmpeg-devel] [PATCH, v4] lavc/vp9: fix reference frame dimensions check for SINGLE_REFERENCE mode

[Fu, Linjie]

> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> Carl Eugen Hoyos
> Sent: Friday, March 20, 2020 00:47
> To: FFmpeg development discussions and patches <ffmpeg-
> devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH, v4] lavc/vp9: fix reference frame
> dimensions check for SINGLE_REFERENCE mode
> 
> Am Do., 19. März 2020 um 16:12 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: Thursday, March 19, 2020 22:13
> > > To: FFmpeg development discussions and patches <ffmpeg-
> > > devel at ffmpeg.org>
> > > Subject: Re: [FFmpeg-devel] [PATCH, v4] lavc/vp9: fix reference frame
> > > dimensions check for SINGLE_REFERENCE mode
> > >
> > > Am Do., 19. März 2020 um 14:45 Uhr schrieb Fu, Linjie
> <linjie.fu at intel.com>:
> > >
> > > > This fix [v4] intended to report errors and exit decode_frame() for the
> > > exact frame witch has
> > > > invalid mvscale factors used, and didn't mean to break the decoding for
> > > subsequent frames if
> > > > they could be decoded correctly.
> > >
> > > How does the output look visually before this patch and how does it
> > > look with this patch?
> > >
> > $ ffmpeg -i g2_decoder_case_15865.ivf -f null -
> >
> > * 1. Before this patch:
> > Reported "Invalid ref frame dimensions" in the decode_frame_header()
> and abort the decoding.
> > (only 8 frame decode)
> >
> > ====
> > [vp9 @ 0x55e6496b3050] Invalid ref frame dimensions 1920x1088 for frame
> size 480x272
> > [vp9 @ 0x55e6496baab0] Not all references are available
> > [vp9 @ 0x55e6496c2510] Not all references are available
> > [vp9 @ 0x55e6496c5620] Not all references are available
> > Output #0, null, to 'pipe:':
> >   Metadata:
> >     encoder         : Lavf58.42.100
> >     Stream #0:0: Video: wrapped_avframe, yuv420p, 1920x1088, q=2-31, 200
> kb/s, 25 fps, 25 tbn, 25 tbc
> >     Metadata:
> >       encoder         : Lavc58.76.100 wrapped_avframe
> > Error while decoding stream #0:0: Invalid data found when processing input
> >     Last message repeated 3 times
> > frame=    8 fps=7.7 q=-0.0 Lsize=N/A time=00:00:00.48 bitrate=N/A
> speed=0.464x
> > ====
> >
> > * 2. With this patch:
> > All frames (12) decoded correctly (visually) with a warning in the header
> check.
> >
> > ====
> > Input #0, ivf, from 'g2_decoder_case_15865.ivf':
> >   Duration: 00:00:00.01, start: 0.000000, bitrate: 100442 kb/s
> >     Stream #0:0: Video: vp9 (Profile 0) (VP90 / 0x30395056), yuv420p(tv),
> 1920x1088, 25 fps, 25 tbr, 1k tbn, 1k tbc
> > Stream mapping:
> >   Stream #0:0 -> #0:0 (vp9 (native) -> wrapped_avframe (native))
> > Press [q] to stop, [?] for help
> > [vp9 @ 0x56072d8df080] Invalid ref frame dimensions 1920x1088 for frame
> size 480x272
> >     Last message repeated 1 times
> > Output #0, null, to 'pipe:':
> >   Metadata:
> >     encoder         : Lavf58.41.100
> >     Stream #0:0: Video: wrapped_avframe, yuv420p, 1920x1088, q=2-31, 200
> kb/s, 25 fps, 25 tbn, 25 tbc
> >     Metadata:
> >       encoder         : Lavc58.75.100 wrapped_avframe
> > frame=   12 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.48 bitrate=N/A
> speed=1.77x
> 
> Then I wonder if the commit message can be improved but that is just
> nit-picking.
> 
> Thank you for your patience!
> 
With pleasure, thank you for the review.

- Linjie