@ Prettz
No, you're wrong. Look into the XviD FAQ, it's written there:
Bias bitrate payback merely adds reserve bytes / payback delay to a frame regardless of it's size whereas proportional adds fewer bytes to smaller frames and more bytes to larger frames.
Btw, it wouldn't be proportional if it distributed more bits to smaller frames but it would be inverse proportional(is that the way you call it in english?
).
Assault