MUX

• Extensions: mux

In 1995, Philips/Infogrames/I-Motion published a game called Chaos Control. Its CD-ROM contains 4 files: A game executable, an installation executable, a readme.txt file, and a 200 MB chaos.gb resource file which contains the game's data. Some of the data files have the extension .mux. These are apparently FMV files.

All multi-byte number are little endian. The file format is laid out as follows:

 bytes 0-27       unknown
 bytes 28-29      video width
 bytes 30-31      video height
 bytes 32-16383   frame offset table

Each frame offset is 32 bits. There is enough space in the chunk offset table for 4087 media chunks. The top 2 bits of each offset always appear to be 1 (so the top byte of the chunk is always 0xC0), so these are probably flags of some sort. The last entry in the table is all 1s (0xFFFFFFFF) and the remainder of the table is all 0s.

Frames contain 1 or more chunks, each of which are formatted in a manner that is reminiscent of the Autodesk FLIC format:

 bytes 0-1    chunk type
 bytes 2-5    chunk size, not including this 6-byte header
 bytes 6..    chunk payload

Known chunk types appear to include:

 0007    unsigned, 8-bit PCM audio
 0070    apparently a palette chunk, 0x300 (768) bytes, and each 
         component is 8 bits (not 6 bits, like VGA palettes are 
         normally stored)
 006F    video chunk
 0005    frame count: 2-byte payload contains frame number

The corresponding video coding format is presently unknown.