[FFmpeg-devel] [PATCH] libavcodec/h263dec.c: Duplicate the last decoded frame when xvid marks the packet as skipped.

[Derek Buitenhuis]

On 10/25/2017 2:42 AM, Thierry Foucu wrote:
> Changed the return value when no VOD were encoded in Mpeg4 bistream.
> And if we do have already a decoded frames and we are not in xvid_packed
> mode, output the existing decoded frame instead of nothing.
> ---
>  libavcodec/h263dec.c       | 9 ++++++++-
>  libavcodec/mpeg4videodec.c | 2 +-
>  libavcodec/mpegutils.h     | 1 +
>  3 files changed, 10 insertions(+), 2 deletions(-)

Would this considerably slow down pathological files with a lot of
NVOPs purposely inserted? For example, it use to be A Thing to use
NVOPs to hack in "variable framerate" Xvid-in-avi encodes, by for
example, setting the fps to 120 for a file with 24 and 30 fps sections,
and padding the rest with NVOPs.

Do we care about such files? (Probably not...)

I can provide some samples, probably, if needed.

- Derek