How to remove audio translations from the movie?
I want to cut an existing movie and want to remove all the language track from it.

ffmpeg -i  -c copy -an video_only.mp4

How do I remove all the soundtracks except the one I need?

ffmpeg -i  -c copy -map 0:a:1 specified.mp4
Reference: http://trac.ffmpeg.org/wiki/Map