Is it possible to retrieve only the audio from a youtube video using the java youtube api?
Very similar to How do I programmatically extract the audio from a YouTube video?.
The top answer there is:
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.
Kudos to John Feminella for the answer.