I am in that 1% hehe. Yes the are in unknown for me format - starts with
DTPK in ASCII (all ShenMue discs even Whats ShenMue). In SOUND folder is also driver file with
AM2/AICAsoundDrv990709/Ver1.70b near start that means it is a AM2 Team format.
AFS files starts with
AFS in ASCII, ADX have
(c)CRI near start of file.
How to rip? Just load ShenMue on chankast and record tracks and sounds

Thats all !!!