[gentoo-user] CLI DVD copy?

I've got 1 DVD that for some reason fails to rip using Handbrake. I
then tried it in dvd::rip and it said it couldn't read the table of
contents. However after all of that the DVD plays fine in xine as well
as on my DVD player so I doubt there is anything truly wrong with the
DVD itself.

I was considering making a copy of this DVD to keep for bug testing in
the future. I'm wondering how to make a copy of a DVD movie at the
command line? All the things I'm finding in Google point to dvd::rip
or other GUI apps. I tried a simple dd copy, ala

dd if=/dev/dvd of=Movie.iso

but that fails also.

Thanks,
Mark