Re[4]: [XviD-devel] scene change detecting in Bframes mode

Radoslaw 'sysKin' Czyz xvid-devel@xvid.org
Tue, 20 Aug 2002 19:38:45 +0930


> Maybe as a first step we should simply adopt DX50 style: No B-frames
> just before an I-frame. (PBBPBBPPPI) instead of (PBBPBBPBBI), then we
> can make it into a general setup to "change encoding order" for a chunk of
> frames.

in my opinion, PBBI pattern doesn't make sense if there was a scene
change. The B frames will simply only use forward prediction, as they
won't find any reference in next-scene's I.

Encoding P instead of B sounds good, but the PP<scane change>PPI -
well not really... you can keep doing Ps instead of the I.

Yes, the encoding order would have to be changed for my idea to work.
The bitstream order, however - not. You don't put anything into
bitstream until you have next P frame available and coded, anyway.
Until then, you have all frames between previous P and current
P-candidate, and you can choose modes for them and encode them in any
order you want (just some buffering is needed if you encode in
different order than you put into bistream...).