Google search for 'dvd to mp3' and 'mp4 to mp3' brings up numerous hits...sorry, I haven't attempted this yet (I have thought about it though! My son loves a certain music video...but do I want to listen to it more?) so I can't make any specific recommendations. My guess would be that there isn't going to be a lot of difference in the quality of programs...I would try to find one that's free, has the most features, and/or has the most user-friendly interface.

Good Luck