[XviD-devel] A SSIM Plugin for XviD

[Johannes Reinhardt]

Hi,

first thanks for reviewing and commiting.
>    forgot to mention:
>
>   
>> Message du 13/10/06 11:09
>>     
>>> The computation of ssim is slow. I tried to speed it up with a bit asm,
>>> but I have not coded in asm before. It would be great if some of the asm
>>> wizards could comment. It can be sped up more by reducing accuracy, by
>>> changing GRID to 2 or 4. But there seems to lurks a bug, as this 
>>> sometimes gives strange results. I will look into this.
>>>       
>>   also: since MMX is mixed with floats, i fear some emms() were
>>   required, which i added. Could be an explanation for the strange
>>   behaviour.
>>     
>
>   there's a small bench for ssim functions included in xvid_bench.c too,
>   which shown no problem (unless the bench is itself broken, of course).
>   
Attached is a patch that corrects a typo in xvid_bench.

The bench reports an error for lum_2x8 here (it gives -763 instead of 
-841).
Typo or a real problem?

I found the source of the strange behaviour, it was a stupid typo. Patch 
attached
(also does some cosmetics)

Is there a reason why the plugin setup in encraw around line 1907 is in 
#ifndef?
The errormap visualization code for X is disabled, so it should also 
build under win.

The SSE2 implementation of consim is not faster than the mmx version 
with all CPUs
(Pentium IV and Pentium M) I tested. Is there a chance to speed it up or 
should I
disable SSE2? Or is SSE2 perhaps faster on other CPUs?

Johannes