Duck TrueMotion 2

• FOURCCs: TM20
• Company: On2 (formerly Duck)
• Patents: U.S. # 6,327,304, "Apparatus and method to digitally compress video signals"
• Samples: http://multimedia.cx/samples/ducktm2/

Duck TrueMotion 2 relies of differential coding of samples in a YUV colorspace and coding those deltas using Huffman codes.

Codec principles

This codec employs data separation, so frame is composed from these segments:

1. luma deltas for hi-res blocks
2. luma deltas for low-res blocks
3. chroma deltas for hi-res blocks
4. chroma deltas for low-res blocks
5. values for updating whole block
6. motion vectors
7. block types

Each segment is compressed with own Huffman codes (Huffman tree is stored in segment header), thus gaining compression from grouping similar data.

Games Using Duck TrueMotion 2

These software titles are known to use the Duck TrueMotion 2 video codec to encode full motion video:

Final Fantasy VII (Windows)