[FFmpeg-devel] strange seek problem matroska andavcodec_flush_buffers
Reimar.Doeffinger at gmx.de
Sun Feb 19 19:53:13 CET 2012
On Sun, Feb 19, 2012 at 01:47:27PM -0500, Don Moir wrote:
> >>>The thing is, the "bad_seek_matroska_strange" file is a worst case
> >>>of this of the files I have. Some other files I have, have a very
> >>>slight indication of this. Maybe something like 1/8 to 1/4 of a
> >>>second. In these cases, settting CODEC_FLAG2_SHOW_ALL is worse
> >>>because you will see distortion where previously it was clean. While
> >>>seeing the distortion is helpful in some cases, I have more files
> >>>that are effected negatively by it.
> >>I may be missing something, but this should be a bug, the demuxer
> >>should be seeking exactly to a keyframe and CODEC_FLAG2_SHOW_ALL
> >>should not make the slightest difference at all.
> >That's what I was thinking but wasn't sure how error concealment
> >came into play there.
> If this is a bug, I think it will be effecting libavcodec/h264.c and
> possibly libavcodec/mpeg12.c. I have an mpegts file with the same
> problem but this file as well as the "strange" file are both
> CODEC_ID_H264. I don't know what relationship mpeg12.c has if any,
> but just so you know.
No, the bug if would be in the demuxer if anything.
However the thing I missed is that with rawvideo (-ES, also -TS and -PS)
we currently don't even try to seek to keyframes, so for those
that would indeed be normal behaviour (even if it potentially should
For ogg, mkv, nut, avi, ... it _should_ be a bug though if you have
some of these behaving like that.
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