A simple method to convert audio from FLV files (YouTube videos) into .mp3 files using VLC

1. Open FLV file with VLC by drag and drop and press stop as it starts to play.
2. Export the file by opening the VLC Wizard: File -> Streaming/Exporting Wizard…
3. Select Transcode and press Next.
4. Select your file from the list and press Next.
5. Check only the Transcode Audio checkmark and leave Transcode Video unchecked. Select 192 kb/s and .mp3 as audio codec, press Next.
6. Select MPEG-1 as Encapsulation format, press Next.
7. Save the file with any name ending with .MPG
8. Open the created .MPG file again with VLC, press stop.
9. Export the file by opening the VLC Wizard again.
10. Select Transcode and press Next.
11. Select your .MPG file from the list and press Next.
12. Check only the Transcode Audio checkmark and leave Transcode Video unchecked. Select 192 kb/s and .mp3 as audio codec, press Next.
13. Select RAW as Encapsulation format, press Next.
14. Save the file with any name ending with .MP3 or .mp3