Linux: "video to mp3"

Problem: I have video file with concert or music show and I would like to play it in car or on phone.

I both cases it is enough to have audio track and it is necessary to have correct format. My car radio can play only mp3 files (and of course regular cdda).

Here are steps how to get sound track from video and store it as mp3. It is possible to do it directly via ffmpeg but I prefer lame mp3 creator. Depending on source I normalize tracks before converting to mp3. This is also recommend only on lossless file formats.