IAVF

• Extension: AVI
• Company: Take-Two Interactive

This format packs another animation format for (presumably) making videos more interactive. It embeds audio tracks and Flic Video or Smacker video.

Internally the file consists of 145-byte header and various commands with 14-byte header.

File header:

 8 bytes - "IAVF2.00"
 4 bytes - always zero?
 4 bytes - always zero?
 4 bytes - number of frames
 4 bytes - always zero?
 4 bytes - always zero?
 2 bytes - sampling rate
 1 byte  - number of channels
 1 byte  - bits per sample
 4 bytes - bytes per second
 4 bytes - audio block align
 1 byte  - unknown
 4 bytes - some offset or size
 2 bytes - frames per second
 2 bytes - width
 2 bytes - height
 4 bytes - some size
 4 bytes - some size
 4 bytes - some size
 4 bytes - some size
 (the rest 78 bytes are zero)

Command header:

 2 bytes - command ID
 4 bytes - metainformation 1
 4 bytes - metainformation 2
 4 bytes - metainformation 3

Known commands:

• 0x66 - audio payload. First field is sequence number, second field is the expected audio block size, third field is actual data length
• 0x67 - some pause command
• 0x68 - clear frame command (no payload expected)
• 0x69 - 20-byte mouse region information followed by 128-byte FLI header
• 0x6A - 20-byte mouse region information followed by Smacker header (the same as in SMK file but without frame sizes)
• 0x6B - unknown, probably FLI frame data
• 0x6C - SMK frame
• 0x70 - EOF (not necessarily present)
• 0x75 - some audio command
• 0x76 - unknown
• 0x77 - unknown, probably related to Smacker
• 0x78 - Smacker preload data