News: XviD 1.1.0 beta 2

[Didée]

Originally posted by Heini011
it seem's that min quant=3 for b-frames was not a good idea for some reason.
Yeah ... that's a "feature" ;) of XviD in the quantizer settings: The "min" and "max" quant settings for B-frames do not refer to the real quants for B-frames. They refer to the P-frame quant used in the formula for B-frame quants.

For example, if you've set quant ratio to 2.0 and offset to 0.0, then setting min.B-quant=3 will limit B-frame quants to 3*2.0 = quant 6 ...

Don't know if this is mentioned in crusty's XviD FAQ ?

[Heini011]

thanks Didée!

but one question remains: why shows ffdshow mostly quantizers of 4 and not 5 : 3*1.5+0.7=5.2

how can i check the real frame types and quantizers used in my second pass encodes?

[AgentX]

I found a problem with the force-keyframe flag of XviD zones.

It seems to fail when the rate control parameter is changed from zone to zone.

An example will explain what I mean:
Frame=0 Q=31
Frame=100 W=1,0
Frame=200 Q=31
Frame=300 W=1,0
Frame=400 Q=31
Frame=500 W=1,0
...
(all marked with keyframe flag)

The I-frames aren't generated in the exact positions or not at all.
When using Q=20 some I-frames were generated on the right position.
With Q=5 it seems the I-frames are generated okay.

[LigH]

{ Edit: Sorry - it is hard to find that too short XviD encodes with B-VOPs are the result of a VirtualDubMod bug, not XviD's fault... }