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

[Michael Militzer]

Hi,

> > > 1) green smearing bug
> > > If I use the default values in export_xvidcvs and a high bitrate, the
> > > movie gets more and more green. At low bitrates it is not visible :-)
> > >
> > IDCT bug, could someone from xvid team try to decode these with the
> > reference IDCT? in libavcodec it looks bad with the simpleidct & the
> > reference idct but looks ok with walkens IDCT, iirc xvid uses walkens
> > idct (=libmpeg2 idct) ...
> I don't know, i'am not a xvid developer :-)

well, I am ;-)
yes, we're using the Intel AP922 based idct including walkens rounding
trick. The green_bug avi decodes fine with xvid, but when using the
reference idct the evil green becomes also visible... - I wonder what would
happen if we'd use a different fdct implementation to encode the clip.
However we would need the original clip for that... Markus, could you
provide the problematic part in the original format?

> But Edouard Gomez posted a new version of the vbr lib on transcode-devel
> and I made some more tests (all tests are without bframes )
>
> original transcode 0.6.0 final :
>
> export_xvidcvs.so module + latest xvidcvs lib -> picture ok
> export_xvid.so module + xvid snapshot  20020412 lib -> picture ok
>
> transcode 0.6.0 final + new export_xvid modules with vbr_lib:
>
> new export_xvidcvs.so module + latest xvidcvs lib -> green bug
> new export_xvid.so module + xvid snapshot  20020412 lib -> green bug
>
> Perhaps there is a bug in the new export_xvid module?

maybe there really is one, but I'm sure it does not cause this green bug
problem ;-)

bye
Michael