For a while now I have been searching for a simple and elegent solution for backing up my DVD’s to divx. There were plenty of Windows freeware and trialware that did the basics, but none of what I tried seem to properly encode 5.1 channel AC3 surround, for me a movie is nothing without surround sound once you get used to it, why settle for stereo when surround is possible? Much of the software had clunky interfaces and didn’t behave as expected.

Then I came across the gem that is mencoder, I came across this as part of the Linux mencoder rpm for Fedora Core. With the liba52 audio library and appropriate Xvid codecs installed, a simple two commands will produce a top quality rip with 6 channel AC3 sound. A 1:30 hour movie will produce a 1.2Gb file, give or take.

mencoder dvd:// -ovc xvid -xvidencopts pass=1 -alang en -oac copy -channels 6 -o /dev/null
mencoder dvd:// -ovc xvid -xvidencopts pass=2:bitrate=1200 -alang en -oac copy -channels 6 -o My.Movie.AC3.avi

Mencoder can also be installed on a windows machine, as part of the windows mplayer installation, neccessary codecs along with mplayer itself can be found on the mplayer.hu website.
A note for windows use is to direct output for first pass to nul: as opposed to /dev/null

It is worth using the 2-pass method for highest quality, even though it does add considerably to ripping time.