[Linux] Use Mencoder to transcode the movie file (avi->mp4, ogv->avi)

AVI to Mpeg4
mencoder input.avi -ovc lavc -lavcopts vcodec=mpeg4 -o output.mpg4 -oac lavc -af lavcresample=48000:srate=48000

mencoder input.ogv -ovc lavc -oac mp3lame -o output.avi

http://ajithc.wordpress.com/2006/09/25/mencoderffmpegtranscode-other-media-relared-scripts/