Types of compression used by surround formats

[Sycho]

I am in the begin of a techincal paper about Dolby Digital vs DTS vs WMA9 vs AAC vs OGG. I basically want to talk about what type of compression each uses and how they are able to go down to extremly low bitrate (well most of them) any one got any ideas?

[Gabriel_Bouvigne]

Dolby Digital is using AC-3 (subband compression), WMA9 is using WMAv2 (transform compression), AAC and OGG are also transform codecs.

[hans-jürgen]

http://www.audiocoding.com/modules/wiki/?page=AAC

The other formats have individual pages in the Wiki, too. You should also follow the internal and external links to find more information.

[Sycho]

Originally posted by Gabriel_Bouvigne
Dolby Digital is using AC-3 (subband compression), WMA9 is using WMAv2 (transform compression), AAC and OGG are also transform codecs. i know that dolby digital is ac3 but what is thetechnical terms for the coding?

[Gabriel_Bouvigne]

AC-3 is a subband compression psychoacoustic encoding scheme.