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FMIM files are used by the Xbox 360 "System Music Player" to store music ripped from a CD. They are stereo WMA 9.1 files, with one pass CBR (constant bitrate) at 192kbps/44.1kHz.


Offset Length Type Information
0x0 0x4 ascii string magic "FMIM" / 0x464D494D
0x4 0x8 bytes magic (?) unknown purpose but always 0x100010001
0xC 0x200 unicode string Track Title
0x20C 0x200 unicode string Album Name
0x40C 0x200 unicode string Artist #1
0x60C 0x200 unicode string Artist #2 (reason for duplicate unknown, locale?)
0x80C 0x200 unicode string Genre #1
0xA0C 0x200 unicode string Genre #2 (reason for duplicate unknown, locale?)
0xC0C 0x4 unsigned int Track Length (milliseconds, to nearest second)
0xC10 0x4 unsigned int Track Number on Album (starts from 0x1)
0xC14 0xF4 bytes Unknown, sometimes contains readable text
0xD08 ... (rest of the file) bytes WMA 9.1 file containing audio as described above