You can try mplayer
[
www.mplayerhq.hu]
Read the manual. You should do something like
mplayer -dumpaudio dvd://
It comes without a GUI, but it is really one of the best audio programs around.
I use to rip audio streams from the net. For instance it can also rip a realplayer stream and convert it into perfect audio. I got a Wolfmother concert on my iPod that way.