How to download an MP3 track from a YouTube video

Install youtube-dl from the official repository in Ubuntu:

sudo apt-get install youtube-dl

To download a video execute the following:

youtube-dl <url>

E.g

youtube-dl http://www.youtube.com/watch?v=_z-hEyVQDRA

You can also specify other options

-b            Best quality

-m            Mobile version

-d            High Definition

-g            Don’t download, just show the url

-c            Resume download of a video which was interrupted before

-w            Don’t overwrite existing file

For complete list of switches execute man youtube-dl in terminal.

Information from http://www.absolutelytech.com/2010/06/26/howto-download-youtube-video-from-command-line-ubuntu/

Converting to mp3

Now install ffmpeg from the official repo.

sudo apt-get install ffmpeg

Next have a look to make sure the flv file has downloaded from youtube by typing

ls *flv

This will list all the flv files you have. What you should see is a flv file with the same name as the 'v' component of the youtube url you downloaded.

E.g if you downloaded http://www.youtube.com/watch?v=_z-hEyVQDRA then you should have a file called _z-hEyVQDRA.flv

Next you need to copy that file name and then put it in an ffmpg command like

ffmpeg -i <file name>.flv -acodec libmp3lame <song name>.mp3

So for this example you would type

ffmpeg -i _z-hEyVQDRA.flv -acodec libmp3lame MasterOfPuppets.mp3

Once this has successfully completed you will now have the mp3 file you were after.

Note For cleanup you may want to type rm _z-hEyVQDRA.flv to get rid of the flv file that you no longer need.

Information from http://ubuntuforums.org/showthread.php?t=855433

REF: https://askubuntu.com/questions/178481/how-to-download-an-mp3-track-from-a-youtube-video

youtube-dl --extract-audio --audio-format mp3 <video URL>

From the online help:

-x, --extract-audio        convert video files to audio-only files (requires

                           ffmpeg or avconv and ffprobe or avprobe)

Bear in mind as well that youtube-dl defaults to using avconv so you should consider specifying either avconv or FFmpeg at the commandline . From the online help :

--prefer-avconv                  Prefer avconv over ffmpeg for running the

                                 postprocessors (default)

--prefer-ffmpeg                  Prefer ffmpeg over avconv for running the

                                 postprocessors