[XviD-devel] Adaptive quantisation

[Dirk Knop]

Hi,

since the new luma masking algorithm was introduced, many people (users) 
complained that they didn't gain compressability.

In adapt_quant.c we find hardcoded values:

    const float DarkThres = 0.25;
    const float DarkAmpl = 7.0;
   
    const float BrightThres = 4.0;
    const float BrightAmpl = 5.0;

    const char LowestVal = 10;

    const float GlobalBrightThres = 220.0;
    const float GlobalDarkThres = 20.0;
    float global_quant = 1.0;

I think we could add some of those values to the xvid api so we could 
"tweak" them via the encoding application ( I have to admit that I 
didn't look deeper into the sources yet to understand all of these 
values...).

Did anyone do some tests and has better values to replace these with, 
would be nice as so there wouldn't be the need for an API change.

Thanks,
Regards,
Koepi