Convert mp4 to mp3

Is it possible to convert mp4 to mp3 on here?
I would like to make a converter.

@NezbednikSK, I don’t know much about this and I’m sure other community members will be able to help you, but here’s a video I found that creates the same:

Yeah, I searched around for a bit and that was one resource I also found.

But how are you able to install FFmpeg on here?

Its already installed

$ ffmpeg 
ffmpeg version 2.8.15-0ubuntu0.16.04.1 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.10) 20160609

Did you get that result by typing ffmpeg in the console?

Oh sorry, i forgot to check lol

just change the extension