[XviD-devel] Qpel Problem Samples

[Christoph Lampert]

On Fri, 5 Sep 2003 iibot at gmx.at wrote:
> I've been on the list for some time but lacked the time to contribute.
> 
> > Too bad, I thought it had worked for me...  :-(
> > Okay, then we simply do a three-pass ;-) Encode the _full_ movie at
> > const quant, with and without qpel, then use the better for third pass...
> 
> I know this was meant as a joke, but I believe things won't slow down much
> if the first and second pass would be interleaved, since they work on the same
> dataset per frame/slice/whatever anyway.

Hm, I'm not so sure about this, because only the incompressed input
picture could be used by both tasks, everything else would almost
immediately differ. No motion vectors etc. could be reused. for the same
reasons as with "hinted MV". 
But on a P4 with Hyperthreading or a SMP system, encoding the same clip at
the same time with and without QPel would of course be faster than one
after the other. 

gruel