For my own amusement, I dumped the files of an old Nintendo DS video game I have (the company has long since gone bankrupt/closed) and am trying to extract the assets. I have recovered game text, videos, and sound, but one 58-MB file by the name of
graph.dat, which contains the game's graphics (probably) is giving me a hard time.
Importantly, the game's text was stored in a custom format which the developers appear to have created for the game, so I strongly suspect
graph.dat to contain a custom graphics format as well.
I was able to break the graphics file into segments by reading metadata records left in a separate file,
graph.dti. The metadata file contained 1910 records, separated by 44 chunks of intermediate data. Each record listed off a set of contiguous addresses in
graph.dat, which yielded three binary data blobs once chunked out of that file.
The first blob in each record, which I've nicknamed 'Huey', might be some sort of header. It's always either 32 bytes or 512 bytes long.
The second blob, 'Dewey', is of variable length, ranging from 704 bytes to 49 KB in size. I suspect it contains the actual image data.
The third blob, 'Louie', is always 1536 bytes in size.
I suspect 'Huey' may be color palette data, and 'Louie' is some sort of color index, but I can't be sure.
Does anyone have any ideas? Tossing 'Dewey' into GIMP's raw data import was spectacularly unsuccessful.
Link to a sample of four different images (I'm assuming) from the file. Filenames were provided by my unpacker tool and were not present in the original metadata. I have 1,906 more of these where this came from, so just ask if you need them.