BFI

• Extensions: bfi
• Company: Tsunami
• Samples: http://www.mplayerhq.hu/MPlayer/samples/game-formats/bfi/

Blue Force by Tsunami is at least one game that uses a multimedia format with the extension .bfi. All multi-byte numbers are little endian. The general FourCC chunk format is as follows:

 bytes 0-3    chunk type
 bytes 4-7    chunk size, including 8-byte preamble
 bytes 8..    chunk payload

A BFI file begins with the following header:

 bytes 0-3      file signature: 'BF&I'
 bytes 4-7      total file size
 bytes 8-11     total header size
 bytes 12-15    frame count
 bytes 16-43    unknown
 bytes 44-47    video width
 bytes 48-51    video height
 bytes 52-55    framerate
 bytes 56-59    number of valid palette entries (?)
 bytes 60-827   256 RGB triplets (6-bit VGA palette values)
 bytes 828-831  audio sample rate
 bytes 832-835  audio channels (?)
 bytes 836-959  unknown

The media frames follow the header. Each frame is packaged inside a chunk with the fourcc 'IVAS' (possibly Interleaved Video and Sound). A IVAS chunk has the following payload:

 bytes 0-11    unknown
 bytes 12-15   size of audio data
 bytes 16..n   unsigned, 8-bit PCM audio data
 bytes n..     encoded video data  

The details of the video coding are presently unknown.