For the complete list of available options, please read the man page. The syntax to play a standard DVD is as follows:
mplayer dvd://1 -dvd-device /dev/hdc
If you have compiled MPlayer with dvdnav support, the syntax is the same, except that you need to use dvdnav:// instead of dvd://.
The default DVD device is /dev/dvd. If your setup differs, make a symlink or specify the correct device on the command line with the -dvd-device option.
libdvdcss for DVD playback and decryption. These two
libraries are contained in the
MPlayer source tree, you do not have
to install them separately. You can also use system-wide versions of the two
libraries, but this solution is not recommended, as it can result in bugs,
library incompatibilities and slower speed.
In case of DVD decoding problems, try disabling supermount, or any other such facilities. Some RPC-2 drives may also require setting the region code.
DVD decryption is done by
libdvdcss. The method
can be specified through the
variable, see the manual page for details.
DVD drives nowadays come with a nonsensical restriction labeled region code. This is a scheme to force DVD drives to only accept DVDs produced for one of the six different regions into which the world was partitioned. How a group of people can sit around a table, come up with such an idea and expect the world of the 21st century to bow to their will is beyond anyone's guess.
Drives that enforce region settings through software only are also known as RPC-1 drives, those that do it in hardware as RPC-2. RPC-2 drives allow changing the region code five times before it remains fixed. Under Linux you can use the regionset tool to set the region code of your DVD drive.
Thankfully, it is possible to convert RPC-2 drives into RPC-1 drives through a firmware upgrade. Feed the model number of your DVD drive into your favorite search engine or have a look at the forum and download sections of "The firmware page". While the usual caveats for firmware upgrades apply, experience with getting rid of region code enforcement is generally positive.