Dune 2 SHP file format
Sourced from Red Horizon Utilities by Emanuel Rabina
The Dune 2 SHP file, is a multiple image filetype, where each image can have
it's own set of dimensions. The file is structured as follows:
NumImages (2 bytes) - the number of images in the file
Offsets[NumImages + 1] - offset to the image header for an image. The last
(2 or 4 bytes each) offset points to the end of the file. The offsets
don't take into account the NumImages bytes at the
beginning, so add 2 bytes to the offset value to
get the actual position of an image header in the
The size of the offsets can be either 2 or 4 bytes. There is no simple way
to determine which it will be, but checking the file's 4th byte to see if
it's 0, seems to be a commonly accepted practice amongst existing Dune 2 SHP
eg: A 2-byte offset file: 01 00 06 00 EC 00 45 0A ...
A 4-byte offset file: 01 00 08 00 00 00 EC 00 ...
The marked byte will be 0 in 4-byte offset files, non 0 in 2-byte offset
Lastly, like C&C SHP files, there is an extra offset, pointing to the end of
the file (or what would have been the position of another image header/data
Following the file header, are a series of image header & image data pairs.
The image header is structured as follows:
Flags (2 bytes) - flags to identify the type of data following the
Datasize field, and/or the compression schemes used
Slices (1 byte) - number of Format2 slices used to encode the image
data. Often this is the same as the height of the
Width (2 bytes) - width of the image
Height (1 byte) - height of the image
Filesize (2 bytes) - size of the image data in the file
Datasize (2 bytes) - size of the image data when Format2 encoded/compressed
Regarding the flags, there seem to be 4 values:
- 00000000 (0) = Decompress with Format80, then Format2
- 00000001 (1) = (see 3)
- 00000010 (2) = Decompress with Format2
- 00000011 (3) = A small 16-byte lookup table follows, and the image data
should be decompressed with Format80 then Format2.
- 00000101 (5) = The first byte gives the size of the lookup table that
follows, and the image data should be decompressed with
Format80 then Format2.
And after this image header is the image data.