Re[10]: [XviD-devel] New Motion Estimation (from sysKin) committed to branch

Marc FD xvid-devel@xvid.org
Fri, 27 Sep 2002 21:18:00 +0200


I'm not 100% sure if it's called "misplaced MBs", but i see that i've some
ugly errors in movment, and they stay and smear until the next kf. i wasn't
using B-frames at all !! i used bframes = -1
i saw the bug with VDub (so decoded by XviD i think)


> Marc FD (marcfd@free.fr) wrote:
> > SysKin, i've tested the new 2 pass hinted ME without Bframes,
> > and i gives me misplaced MBs, like Koepi. i used today's CVS.
> > is it normal ? (sounds like a bug for me)
>
> Are you sure it is really misplaced MBs, because i'm suffering strange
> bugs too with bframes but they are all decoder related.
>
> If i encode a test sequence with bframes, and then i use ffmpeg libavcodec
then i get misplaced Mbs during playback. But if i write the mpeg4 bitstream
directly to a file and i use xvid_decraw to decode it, then frames are just
as expected.
>
> So there're 3 possibilities :
>  - libavcodec is right and something's is wrong in xvid-devel encoder
>  - libavcodec is right and 2 bugs are compensating each other in xvid
>  - libavcodec is wrong and xvid does the job just well.
>
> But afaik, avcodec had always played fine bframe clips with old ME, so
> it's probably one of the 2 first solutions.
>
> --
> Edouard Gomez
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