[XviD-devel] [BUG] Pink Frames (still lacks fix) ++

[Christoph Lampert]

On Thu, 15 Aug 2002, Dead2 wrote:

> > > In my opinion the red and blue dc coefficients are saturated
> > > by  a bug in  the bitstream  writer or  a MB  coding bug  (remainder :
> > > blue+red give pink :-) because pink MBs have an pink average color and
> > > the dc coefficient is the average chroma value of MB so...
> >
> > Nono, pink is not red+blue (that's RGB mode, forget it). Pink is the
> > channel with "pink vs. green" (which is either U or V, I don't
> > remember; the other is "blue vs. yellow". I hope.)
> 
> Yep, this is the same problem as in the [XviD-devel] [BUG] thread.

Bug found, bug squashed, problem fixed.

It was motion compensation for chroma components. 
That tried to use image-based interpolation as soon as #BFRAMES was
defined, but that only works if XVID_HALFPEL is on. 
The combination b-frames + non-halfpel is not possible, of course, but
the combination BFRAMES + non-halfpel, say exactly when max_bframes=0
or max_bframes=-1. 

So we'd better check for XVID_HALFPEL in motion_comp.c, even when 
BFRAMES is active.

gruel


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