TMM-Frac

• Company: Total Multimedia

This is a format that employs licensed Iterated Systems Fractal Codec and was used for some interactive video discs in DOS era.

Multimedia data is stored in blocks of 0xF800 bytes long that comprise several frames with audio and video data.

Block header format:

 32 bits -- 0x007C0EBF
 16 bits -- 0x007C (normal block) or 0x0000 (last block)
 16 bits -- number of frames in block

Frames start with a header:

 16 bits -- video frame flags (or some unused value for audio)
 16 bits -- frame type (0x000C - video, 0x0700 - audio)
 16 bits -- audio frame size (or some unused value for video)
 16 bits -- video frame size

Audio is stored as 8-bit 22kHz mono PCM, for video the part starting with motion offsets count is transmitted.

First block starts with a header, at offset 0x24 there's an absolute offset to the palette data and frame data usually starts at offset 0xb3.