Harrow Media VDO

Company: Harrow Media Extension: vdo

This is a simple RLE-based animation format used in their promotional game.

File starts with the following header (all values are little-endian):

 "Artform\0"
 16-bit version (0 or 1)
 16-bit width
 16-bit height
 16-bit unknown (usually zero)
 768-byte palette

Then frame data with the following header follows:

 16-bit x offset
 16-bit y offset
 16-bit current frame width
 16-bit current frame height
 32-bit unknown
 32-bit frame size

Frame data is split into line data, each one starting with 16-bit size and with the following RLE scheme: each opcode has length stored in its low six bits and actual operation in top two bits (00 = run, 01 = copy, 10 = skip, 11 = ???).

Some empty frames may be coded with x offset equal to full width and current frame width being negative full width (and the same applies to height) as well as size being zero.