I can not get xine, SMplayer, or VLC media player to
play a DVD that I know is good. I have already installed
libdvdcss-1.2.11
On the same computer I have another distro installed and
it plays this DVD with no trouble. What's so odd about
Lubuntu 12 ?
The only error report I got was from xine:
video_decoder can't raise nice priority by 1: operation not permitted
video_decoder can't raise nice priority by 2: operation not permitted
I'm logged in as user. Lubuntu makes a big deal of how
root is never to be used, so I assume this is not an issue.
Anybody got any ideas ? I don't understand this at all.

I don't know if this matters, but I noticed that in
the distro in which I can play video dvds, that the
libdvdcss files are installed in /usr/lib
In Lubuntu 12, in which I can not view video dvds, the
libdvdcss files are installed in /usr/local/lib
-rw-r--r-- 1 root root 164596 Nov 1 11:50 libdvdcss.a
-rwxr-xr-x 1 root root 932 Nov 1 11:50 libdvdcss.la
lrwxrwxrwx 1 root root 18 Nov 1 11:50 libdvdcss.so -> libdvdcss.so.2.1.0
lrwxrwxrwx 1 root root 18 Nov 1 11:50 libdvdcss.so.2 -> libdvdcss.so.2.1.0
-rwxr-xr-x 1 root root 105833 Nov 1 11:50 libdvdcss.so.2.1.0
Does this matter ? If so, how do I get libdvdcss files
installed into the /usr/lib directory ? Can I just copy them there ?

I don't use Lubuntu but had similar problems with Ubuntu. Installed libdvdread4 and libdvdcss and ran the command:

sudo /usr/share/doc/libdvdread3/install-css.sh

Check if the bash script is there. It worked after for me.

Thank you very much ! It works for all of them, xine, VLC, and SMplayer.
This thread has been solved by you. Thanks again.