[XviD-devel] GMC rc2

[Christoph Lampert]

On Sun, 12 Jan 2003, Dirk Knop wrote:

> Hi,
> 
> Christoph Lampert wrote:
> 
> >QPel + GMC is fixed, please test everything in ASP (QPel, Bframes, GMC). 
> >
> >There is no support for interlace (yet) or reduced res (ever). 
> >
> 
> Ok, did a first test on "Das Boot". According to sysKin I modified line 
> 1764 in encoder.c to have a "better" gmc/no-gmc decision (in terms of 
> filesize). Changed it to
> 
> if (iSAD + 12 <= pMB->sad16) {        /* mode decision GMC */

I tested different constants there, too. I always got different results,
sometimes larger was better, sometimes not, sometimes even negative
values. I guess it depends on the quality of GME, and for the moment, I
left the values at 0. 

 
> Used features:
> - GMC
> - QPel
> - bframes 3/150/100
> 
> libavcodec/ffdshow (from 13.12.2002)  doesn't decode the resulting video 
> correctly, it smears MBs through the image (looks funny though). 

Yes, I'm in contact with them about that. I have to admit that I don't
know which implementation is correct. Most likely both are not... 

> Decoding with xvid is working flawless of course.

If you knew how much time this "of course" took me... 

> With GMC, the "dark block flickering" problem is worse, they appear more 
> often.

I'm not aware for that, what is it?

> Other than that the resulting video looks really nice. Good work! :)

Thanks, but at the moment, I doubt that GMC really improves much. But I
haven't tested with B-frames, so maybe there's a diference. 

gruel