Ravenloft ANM

• Company: DreamForge
• Extension: ANM
• Game: Ravenloft

This is a simple RLE-based cutscene format. The header contains 16-bit number of frames and version. Then frames consisting of one or more chunks follow.

Frame starts with 16-bit number of chunks followed by chunks, each with 16-bit type and 32-bit size.

Chunk types are:

• 0 - VGA palette
• 1 - clear palette command
• 2 - intra RLE
• 3 - inter RLE
• 4 - repeat decoding previous chunk 16-bit times at 32-bit offset
• 5-7 - some game engine commands
• 8 - raw image interleaved by factor four (i.e. each line stores pixels in order 0 40 80 120 1 41 81 ...)

Intra RLE is trivial: read one-byte opcode, non-negative values mean copy length minus one, negative values mean run length minus one.

Inter RLE operates on updating columns of video: first 16-bit number is how many areas to update there are, each one starts with 16-bit left offsets and 16-bit number of segments to update. Each segment is coded as 16-bit number of pixels to skip (vertically) plus how many pixels to update (also vertically), followed by pixel values.