iPod Can I extract audio from a dvd and transfer it to my ipod?

I have a collection of operas on dvd. I would like to be able to extract the audio only from the discs for transfer to my 5G ipod. I know I can extract the main feature but I don't really want to watch them on my ipod, just listening will do. Transferring the whole movie takes up a lot of space and playback will, I presume, be bad for battery life when all I want to do is listen.

So, can I just extract the audio and transfer to my ipod? And of course, if the answer is 'yes', how do I do it?

Any suggestions/advice will be most appreciated.

rb

many thanks for the pointers and apologies for covering old ground.

FWIW, (and just in case there are any other opera fans interested in doing the same) I did the following and it works very well:

I used 'Mac the Ripper' to extract the main feature from the dvd and I used 'Handbrake' to convert the video into a format usable on my ipod. This is as per http://guides.macrumors.com/How_to_Rip_a_DVD_to_a_Gen5_iPod
An additional very useful feature of Handbrake is that I could select english subtitles and incorporate them into the final movie, very useful for Italian opera! The conversion process was extremely long and I guess the incorporation of subtitles slowed it down, definitely an overnight job.

I used a programme called MPEG Streamclip to demux the original vob file from the main feature I had ripped to my hard drive with MTR. This gave me an AIFF audio file and a m2v movie file. I imported the AIFF file to itunes and used itunes to divide it into tracks and convert from aiff to mp3.

Finally I burned the mp4 (the ipod usable movie), the AIFF audio file (very large) and the mp3s onto a data dvd as a backup and finally I deleted everything I didn't need cluttering up my hard drive, keeping only the movie version for my ipod and the mp3s on my ibook.

All of the software I used was free. It was a bit fiddly dividing up the aiff into seperate tracks but other than that very straightforward.

rb