M4P file format
|The M4P format is an encrypted version of the MPEG-4 Part 14 multimedia container format that is used to store digital audio content that has been protected by Apple's FairPlay digital rights management (DRM) system. This format was developed by Apple as a way to restrict unauthorized copying and distribution of digital music files purchased from the iTunes Store.
|The M4P format uses Advanced Audio Coding (AAC) as its audio codec and supports a range of bitrates and sample rates. The FairPlay DRM system used by M4P files employs a combination of encryption and authentication mechanisms to ensure that the content can only be played on authorized devices.