[XviD-devel] PlainC optmization

[Christoph Lampert]

On Wed, 5 Mar 2003, Michael Militzer wrote:
> Anyway, the main difference between my qel avg mmx functions and the "old" mmx 
> halfpel interpolate functions are not that I use two (or four) pointers but 
> that I calculate everything in packed bytes (and then have to introduce 
> additional instructions to cope with possible overflows) while the normal 
> interpolate code operates on words. Even though there is some additional 
> complecity introduced, overall instruction count is reduced when using bytes 
> instead of words.
> 
> So it should be also possible to speed up interpolate8x8_hv by replacing the 
> packed word interpolation code with new packed bytes one...

Hm, where is interpolate8x8 used btw.? 

I found it at  image_interpolate. Are we kidding? Do we really
interpolate a 720x576 image by calling interpolate_8x8() almost 10000 
times? And that again three times, for H/V/HV? 

Then it's also in ChromaSAD (could of course be replaced/remove if we
do image based chroma as it's already default for bframes). 

Is that it? 

gruel