ipod library 操作神文

http://www.subfurther.com/blog/2010/07/19/from-iphone-media-library-to-pcm-samples-in-dozens-of-confounding-potentially-lossy-steps/

http://www.subfurther.com/blog/2010/12/13/from-ipod-library-to-pcm-samples-in-far-fewer-steps-than-were-previously-necessary/