I asked this in an email nearly a month ago now and I got the automated response but never saw a human's reply. Time to try my chances on the Lone Wolf forum 
I've been looking at the .ab file format at a low level and it appears to be a quite simple archive format. The main thing I don't know but am interested in at the moment is what the compression format is for the files. Relic's SGA files in Dawn of War just use deflated/zlibed, but the .ab files don't seem to contain be deflated/gzipped/bzipped (or at least not that I've been able to work with so far).
Can anyone enlighten me on the compression algorithm used?
Thanks,
IBBoard

I've been looking at the .ab file format at a low level and it appears to be a quite simple archive format. The main thing I don't know but am interested in at the moment is what the compression format is for the files. Relic's SGA files in Dawn of War just use deflated/zlibed, but the .ab files don't seem to contain be deflated/gzipped/bzipped (or at least not that I've been able to work with so far).
Can anyone enlighten me on the compression algorithm used?
Thanks,
IBBoard