[XviD-devel] dark blocks in b-frames

[Christoph Lampert]

On Fri, 14 Feb 2003, Dirk Knop wrote:

> Hi,
> 
> no, this happens in bframes - qpel just amplifies the effect a little IMO.

Crucial question, since I'm still not sure it's a bug: Are flickering
dark blocks also there with bquant_ratio == 100 ? 

Couldn't it simply be a quantization problem which happens in Bframes
because quantizer is higher there, so a difference of 1 in the quantized
values is really visible? This doesn't happen in P-frames with high
quants, because there overall quality is worse, so you don't notice the 
"bad" block. On in the mixture between high quality reference pictures and
highly quantized differential image it's more visible? 

gruel