How do I programmatically extract the audio from a YouTube video? [closed]

Question

I'm trying to create a C# application which allows me to extract just the audio from YouTube videos. I've come across sites that already do that, but I'm not sure how they actually work. What would be the best way to do this programmatically?

Thanks for any advice

Answer 1

Writing an application for this might be overkill. Existing tools already do a pretty good job, and it's hard to beat their simplicity:

wget http://www.youtube.com/get_video.php?video_id=... |
  ffmpeg -i - audio.mp3

All done!

If your application needs to do something special with the audio afterwards, it would make sense to write an app for that part. But for just getting the audio out, shelling out to ffmpeg will be a lot easier.