Downloading

I used a small python script youtube-dl for downloading the video data.

• It is available in the Ubuntu repositories

  sudo apt-get install youtube-dl

• If you encounter some problems you also could do a source checkout from BitBucket (requires that Mercurial is installed):

  hg clone http://bitbucket.org/rg3/youtube-dl/

• Download the video from a terminal:

   youtube-dl http://www.tube.com/watch?v=videoid

• After the download you will find a videoid.flv in your folder

Getting the audio data

For extracting the audio data I used ffmpeg.

• If you haven’t installed it already:

  sudo apt-get install ffmpeg

• We will extract the audio data to a simple wave file. This file is gonna be large, so make sure you delete it afterwards.

  ffmpeg -i videoid.flv output.wav

Converting to MP3

For converting the wav file to a mp3 file I used lame.

• Run (the “-b” arguments sets the bitrate of the mp3):

  lame -b 192 -h output.wav output.mp3

Notes

• There a lot of other ways to get the data. Instead of lame you could use mplayer, but this way I alway ended with broken mp3 files.
• Instead of converting to wave file you also could create a mpeg video and then create the mp3 file directly from this video.
• Lame and also ffmpeg have tons of options available from the command line, which could increase speed and quality of the conversation.