ACG Movie

• Extensions: .m24, .wdf

This is a family of auxiliary animation formats i.e. formats that are used as an animated overlay for some background and do not code whole area themselves (8-bit version does not contain image palette either). The formats employ Microsoft RLE for compression.

8-bit ACG movie

File starts with "ACG_MOVIE" string and does not seem to contain anything useful until the offset 0x24C. From there there's frame data prefixed by two 16-bit values and RLE data. The frame ends where RLE data signals end of data.

8-bit ACG difference movie

Nothing is known about it beside the fact that it starts with "ACG_DIFF8".

24-bit ACG movie v1

Nothing is known about it beside the fact that it starts with "ACG MOVIE TRUE24-BIT".

24-bit ACG difference movie

Nothing is known about it beside the fact that it starts with "ACG_DIFF24".

24-bit ACG movie v2

File starts with "ACG MOVIE TRUE24- V2" string followed by 16-bit number of the frames, bounding rectangle (32-bit x, y, width and height values) and 16-bit value which looks like height aligned to multiple of 4. Frames start with similar bounding rectangle, 32-bit size (repeated twice) and two 16-bit values. Frame data consists of 24-bit image data compressed with the same 8-bit RLE per plane (i.e. first it's blue component of the whole image, then green and finally red) stored one after another (decoder has to rely on the RLE signalled end-of-data to determine where next component data starts).