Question about recording a CD from a DVD

I went on a shopping spree and bought a ton of live concerts on DVD.  I want to record them to Cd so I can listen to them in my car when I'm on the road. When I try to record the music to a CD (optical connections) it won't record. I get a message that it is being blocked (NOT PERMITTED).
Does anybody know if there is a way to get around this? I would rather record it with the optical setup (better sound quality) rather than having to convert it to analog.
Any input would be great

Thanks