First of all its not efficient to rip a DVD on Raspberry Pi. I doubt Raspberry CPU/GPU can handle this without hardware acceleration. But you can give a shot for Handbrake.
To use handbrake on Raspberry Pi (or any armv6-hf) do this;
Add apt repository
sudo echo "deb http://honeybadger-apt.zapto.org wheezy main contrib non-free" >> /etc/apt/sources.list
Add the honeybadger GPG key to your apt keyring
wget -qO - "http://honeybadger-apt.zapto.org/index.php?dir=&file=matt.askthebadger%40gmail.com.gpg.key" | sudo apt-key add -
Update repository index
sudo apt-get update
Install handbrake-cli and libdvdread which will provide a library to remove the copy protection
sudo apt-get install handbrakecli libdvdread4
sudo /usr/share/doc/libdvdread4/install-css.sh
To create a DVD ISO file from a VIDEO_TS directory on your hard drive, run the following:
mkisofs -dvd-video -udf -o dvd.iso /folder-with-VIDEO_TS-in-it/
then mount the DVD iso to /mnt
sudo mount -o loop dvd.iso /mnt
This command will copy DVD vob files into a large file without copy protection.
vobcopy -l -o outDir/
Then encode with handbrake-cli
handbrake-cli -i outDir -o movie.mp4 -e x264 -q 20 -B 160 -t 1
-q quality
-B audio compress rate in Kbps
-t title id to convert
-e encode format
If it handbrake-cli can not handle without hardware acceleration you can try this transcoder. I haven't test it, but maybe it can work. just compile it then run;
./omxtx [-b bitrate] input.foo output.m4v
Sources :
http://blog.teamleadnet.com/2012/03/decss-and-convert-dvd-into-h264-video.html
https://github.com/arjenv/omxtx