Aac
The Advanced Audio Coding (AAC) file format is a lossy digital audio encoding format. Files downloaded from the iTunes Music Store are available in this format.
Metadata
AAC files usually have a file ending of .m4p and contain lots of metadata. The output of the Unix strings command suggests that at least the following information is contained:
- Name of the person who downloaded the file from the iTunes Music Store
- Email address of that person (sometimes)
- Timestamp of when the file was downloaded
- Another timestamp (probably the date when the file was put into the iTunes Music Store?)
- The usual metadata of music files (artist, album, cover art etc.)