If you’ve ever downloaded music videos from a website (for example via “youtube-dl”) you may have been in the position of wanting to extract the music in “MP3″ format from the “FLV” (flash video) file, here’s how you can do this:
#mencoder source.flv -ovc frameno -oac mp3lame -lameopts br=128 -noskip -o resampled.avi
#mplayer -dumpaudio -dumpfile final.mp3 resampled.avi
Both “mencoder” and “mplayer” can be used on both Windows and Linux (in the latest version of Ubuntu both are available via the package manager).