libdvdcss

http://www.medibuntu.org can be setup to use only free repositories. You just have to setup manually or run a command afterwards to make it free only.

Just remember that Trisquel 4.0 is lucid, 4.5 is maverick, 5.0 is natty, and 5.5 is oneiric when setting this up. For example, to nab this for 5.0, go in the terminal and type (all one line):

sudo -E wget --output-document=/etc/apt/sources.list.d/medibuntu.list http://www.medibuntu.org/sources.list.d/natty.list && sudo apt-get --quiet update && sudo apt-get --yes --quiet --allow-unauthenticated install medibuntu-keyring && sudo apt-get --quiet update

Then immediately when that completes, do this (all one line):

sudo sed -e 's/ non-free//' -i /etc/apt/sources.list.d/medibuntu.list && sudo apt-get update

When you are done, do apt-get install libdvdcss2 in the terminal since libdvdcss2 is considered free software even though it cannot be included in Ubuntu's repositories for fears of violating DMCA laws. Wikipedia article here if you are interested.

We have documentation on how to do exactly that: Enable DVD Playback

SirGrant just pointed to the best solution, nothing to add here.

I know 5 ways to do that:

1. http://packages.medibuntu.org/natty/libdvdcss2.html
2. sudo sh /usr/share/doc/libdvdread4/install-css.sh
3. http://debian-multimedia.org/dists/squeeze/main/binary-i386/package/libdvdcss2.php
4. http://www.videolan.org/developers/libdvdcss.html
5. compile from source (http://download.videolan.org/libdvdcss/)

NOTE: The VideoLAN website contain both precompited DEBs and source tarballs (this is the difference between point 4 and 5).

Thank you all,

libdvdcss is a free software under GNU/GPL and I've heard that this legal in Canada to play DVD in your computer.

Thanks

What method did you end up using?

I used your way with medibuntu. It work well with my "Lord of the rings" DVD but it read nothing at all for "Iron Maiden - Early Days".

edit: Damn... Sometimes it reads, sometimes it don't...

edit: Everything is fine now. Thanks!