[XviD-devel] Changes to get_pmv2

[Radek Czyz]

Tom Jacobs wrote:
> hi
> 
> in ME is just just the MV for each block that is stored in the bitstream or
> is somehow the prediction there too?
> if a full search is taking place how does the predictions matter? does the
> prediction act as a centre for the search window?
> when the image is decoded does it just use the MV from the MB itself or does
> it look at the neighbours or prediction (if saved).
> im not sure about the differential vector, is this what is actually sorted?
> 
> i know thats alot of questions in one go but am trying to get my head around
> what exactly is happening so i can better what i have to do and what can be
> done in parallel
> 
> Thanks
> 
> Tom

Hi,
The prediction is also used to calculate how many bits a motion vector 
will take in a bitstream. Therefore, even at full search, it's pretty 
much neccessary to have it.

Why won't you parallize b-frames first? Any row of any b-frame can be 
done in any order, so you can easly divide arbitrary number of b-frames 
into arbitrary number of threads. In 1.1, there is VHQ for b-frames, so 
I'm pretty sure ME is slow enough to make it worthy.

Radek