I want to apply post-processing to audio from an iPhone user's music library (i.e. the iPod app). This could happen in a number of ways:
- Piping the media player's output through an Audio Unit.
- Writing a custom audio output device, and having the media player send audio to it.
- Getting direct access to the files in the user's music library.
Are any of these things possible? I know all of them would be on the desktop, but what about the iPhone?