Dion Moult Seriously who ever reads this description.

eliasp says: (25 July 2009)

Shorter and easier to remember:
ffmpeg -i foo.flv bar.mp3

Dion Moult says: (25 July 2009)

@eliasp: Whoops and thanks!

hari says: (25 July 2009)

This is a shameless promotion, but do you know about my app BiaMovE, which is a mencoder GUI I wrote – it has most of the options of mencoder without dumbing down them and I use it myself for ripping DVDs or audio/video conversion.

Take a look: http://harishankar.org/software/biamove.php

Blah says: (26 July 2009)

ffmpeg -i foobar.flv -vn -acodec vorbis -aq 50 -ac 2 flavor.ogg

-vn no video
-aq audio quality (vorbis specific ~ values 1-100)
-ac audio channels
-acodec audio codec

hessiess says: (28 July 2009)

When going from a already lossy source, and encoding into a lossy format you will only degrade the quality of the audio even more. Thus it would be better to use a lossless format like FLAC or even WAV to prevent further degrading the audio quality.

anon says: (5 August 2009)

The audio stream in .flv are already in mp3 format. So you can just do following command
mplayer -dumpaudio foobar.flv
and have a resulting stream.dump file which you can rename to foobar.mp3 (this works the same way for .wmv to .wma and .mp4/.f4v to .aac). No unnecessary re-ecoding so it keeps the quality and is faster to boot.