I would like to be able to pull audio files from a user's iPhone music library and then analyze the audio within my app. I want to produce data such as beats per minute, high frequency, low frequency, etc. In return, I would like to be able to utilize this data for different functions of my app. Any ideas?
Ways to analyze audio in the background of an app?
I think the current way to access the music library is still the "Media Player" framework:
https://developer.apple.com/library/ios/documentation/MediaPlayer/Reference/MediaPlayer_Framework/
You can get the info that iTunes has collected, but I don't think it gives you access to the underlying music files.