I have an external USB DVD drive which works fine with my Win7 laptop; however, when I connect it to my netbook (Ubuntu 14.04), it will not play commercial (encrypted) DVDs.
I have installed the VLC player, libdvdcss2, libdvdread4, libdvdnav4. If I select the no menu option in VLC, I get the message "Playback failure: DVDRead could not read - 1/4 blocks at 0x22a7." VLC does, however, display the name and length of the movie.
This is apparently a software issue since the DVD drive and DVD work fine with WIn7.
sudo ln -s /dev/sr0 /dev/dvd