Mplayer won't play dvd! (was: dvd movie playing)

[Rodolfo Medina <rodolfo.medina@gmail.com>]

It seems that mplayer's installation was successful on my Debian Sarge,
I can also launch it with:

 $ gmplayer

, but when I try to play a dvd, a window opens up saying:

 Failed to open dvd://1.

, and on the terminal there is:

 Playing dvd://1.
 libdvdread: Couldn't find device name.
 Reading disc structure, please wait...
 libdvdread: Can't open file VIDEO_TS.IFO.
 Can't open VMG info!
 File not found: '1'
 Failed to open dvd://1.

. Can anybody provide any help!, thanks in advance.
Rodolfo



P.S.: Below are the steps I did to play dvd's with totem,
      thanks to Vitaliy and  Wackojacko for their replies.
--------------------------------------------------------------
That's what I did in order to play dvd's with totem:
from:

 ftp://ftp.nerim.net/debian-marillat/pool/main/libd/libdvdcss/

I downloaded the package libdvdcss2_1.2.9-0.0_i386.deb and put it in ~/tmp. 
Then:

 $ cd ~/tmp

 # apt-get install liba52-0.7.4 libdvbpsi3 libdvdnav4 libdvdread3 libglib1.2 libgtk1.2 libgtk1.2-common libmpeg2-4 libpng10-0 libtar libwxgtk2.4 libxosd2 ttf-freefont vlc wxvlc

 # dpkg -i libdvdcss2_1.2.9-0.0_i386.deb

 $ totem

, then in `edit > preferences' I chose the desired device
and so I could play dvd movies with totem.
However, I'm not satisfied with the quality:
on my desktop machine the movie walks by jerks,
whereas on the same machine it is properly played with xine
under Mandrake 10.1.
I'll try with mplayer.

Thanks,
Rodolfo