This article describe how to read DVD on Debian testing (actually Jessie) with a multimedia player (like VLC or mplayer)
From the official repository you can install the libdvdread4
package :
apt-get install libdvdread4
Add the following line to your /etc/apt/source.list
:
deb http://www.deb-multimedia.org testing main non-free
apt-get install libdvdcss2