Not sure how well this works although it seems to on my tests.
Originally Posted by drobi
Install mplayer & w32codecs if you haven't already got them.
Get w32codecs from http://packages.medibuntu.org/
sudo apt-get install mplayer
Then in terminal try something like this.
Substitute "test.rmvb" and "test.avi" with the name your files.
mencoder test.avi -oac mp3lame -lameopts preset=128 -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=1200 -ofps 25 -of avi -o test.rmvb
Also, usually better to start your own thread.