I've installed the Ubuntu restricted area packages tried several things but no DVD play. AUDIO CD works fine, I built this system especially for linux all new hardware. dvd drive worked fine in a windows system. could it be a hardware issue, perhaps the drive having no specific name brand such as sony or lite on?
try installing libdvdcss
Open Terminal and paste this
you should no be able to play DVDs
hope this helps
The problem might also be that the DVD is encrypted.
You need the libdvdread4 package which should be installed in Ubuntu 12.04 but which must be configured to work. Run this command in a Terminal
and try to play the DVD again.
You can get some more infos here in the official Ubuntu wiki.
A handful of drive manufacturers enforce regioning at the hardware level, which was the problem I had on my MacBook. If the above answers don't work, you can investigate your drive to see if this is the situation.