mencoder commands

//merge audio with video
mencoder "d:\result.avi" -audiofile "D:\My Music\mm_col\Track01.mp3" -ovc copy -oac copy -o d:\result2.avi

//save audio
mencoder -of rawaudio -ovc copy -oac mp3lame -o d:\o1.mp3 d:\result.avi

//save audio for track id
mencoder -aid 0 -of rawaudio -ovc copy -oac mp3lame -o d:\o3.mp3 d:\wlty.mkv

//save left channel
mencoder -af channels=2:2:0:0:0:1 -of rawaudio -ovc copy -oac mp3lame -o d:\o5.mp3 d:\rain.rmvb

//save right channel
mencoder -af channels=2:2:1:0:1:1 -of rawaudio -ovc copy -oac mp3lame -o d:\o6.mp3 d:\rain.rmvb

//compress video
mencoder d:\testd.avi  -vf scale -zoom -xy 320  -o d:\result5.avi -oac copy  -ovc lavc -lavcopts vcodec=mpeg4