Audio groups

Audio groups basically is detached files with audio data. Audio group 0 is in the data.win directly, higher ones are stored in audiogroupn.dat. The format is a FORM chunk with just AUDO in it.

The SOND entries have two values, GroupID and AudioID. GroupID specifies the file for the group, and AudioID is the index in AUDO chunk for that group, so the structure goes something like this:

snd_sound1: GroupID=0 AudioID=0
snd_sound2: GroupID=0 AudioID=1
snd_sound3: GroupID=1 AudioID=0
snd_sound4: GroupID=1 AudioID=1
snd_sound5: GroupID=0 AudioID=2
snd_sound6: GroupID=1 AudioID=2
snd_sound7: GroupID=1 AudioID=3

If the game doesn't use audio groups, then AGRP is totally empty (you don't even get a default 0 entry for the stuff inside data.win!)