[XviD-devel] xvid + bframes and mplayer/ffmpeg decoding

[Michael Niedermayer]

Hi

On Tuesday 06 August 2002 18:18, Michael Militzer wrote:
> Hi,
>
> > > 2) flashing blocks
> > > If I activate bframes ( -Q 1 ), I get flashing and jumping blocks at
> > > the border. At high bitrates I can see blue and green blocks.
> > > flashing blocks at bottom:
> > > http://www.fh-landshut.de/~mliebl/bug/flash1.jpg
> > > blue block:
> > > http://www.fh-landshut.de/~mliebl/bug/blue1.jpg
> > > movie (5.3 MB):
> > > http://www.fh-landshut.de/~mliebl/bug/blink.avi
> >
> > bug in libavcodec, just fixed in CVS, thx for the bugreport ;)
> > note, there are still some blinking blocks in there, divx5 shows these
> > too, so
> > ill assume these are caused by a bug in xvid ... (havnt checked if these
> > are
> > vissible with xvid too)
>
> Hm, I've not encoded a lot of clips with b-frames yet, but in all my tests
> so far the clips could be played without any problems with the xvid
> decoder. I've also decoded these clips with DivX5 and an (older) version of
> libavcodec (ffdshow): Both displayed wrong blocks but I never came across
> one block that was wrongly decoded in DivX5 _and_ libavcodec. So if you
> have such a clip where this happens (and if this clip was encoded with a
> recent XviD version), it would be great if you could send me a copy...
http://www.fh-landshut.de/~mliebl/bug/blink.avi (yes its the same as posted 
earlier)
the problem seems with the time stuff in the header
 type=2 -> P, type=3 -> B
 incr = modulo_time_base
 increment= vop_time_increment
 type:2 incr:0 increment:20
 type:3 incr:0 increment:19
 type:2 incr:0 increment:22
 type:3 incr:0 increment:21
 type:2 incr:0 increment:24
 type:3 incr:0 increment:23
 type:2 incr:0 increment:1 (IMHO incr should be 1)
 type:3 incr:1 increment:0  

[...]

Michael