Vid to MPEG2

mencoder -oac lavc -ovc lavc -of mpeg -mpegopts format=dvd -vf scale=720:576,harddup \-srate 48000 -af lavcresample=48000 \-lavcopts vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=5000:keyint=15:aspect=16/9:\acodec=ac3:abitrate=192 -ofps 25 -o your_video.mpg your_video.avi(from http://www.linux.com/feature/53702)

Alternatively, tovid or DeVeDe.