sudo mount -t iso9660 -o loop output.iso /media/cd/
The result will be a compatible ISO image which can be played using any video player (Totem, MPlayer, Dragon, etc.).
For those ones who are too ubuntufied, you can use K3B to create a DVD project and select "Create image only" before burn it.
Anyway, thanks for the answers. This site is too different from what I was used to in StackOverflow though, I have to say. It seems that some of you just read the title of the questions before answering. Maybe my English is too bad :)