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

[Carl Eugen Hoyos]

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!

Carl Eugen