This topic was archived here:

https://web.archive.org/web/20230000000000fw_/https://www.zenhax.com/viewtopic.php?t=15528

Haken, posted Fri Jul 16, 2021 2:59 am (65218)

---

This game uses LZSS compression(i think) for some files, i have managed to make a simple decompressor in c#, but i'm struggling with compresssing it back. Tried to see if i could do it with quickbms but the decompressed result was different from the decompressed by the game, maybe probably because the window must be initialized with a pattern of data. Is it possible do decompress/compress these files with quickbms?

aluigi, posted Thu Sep 09, 2021 3:27 pm (66221)

---

It's just the normal lzss with the window initialized using a NUL byte rather than the usual space (0x20).

Decompress script:

Code:

comtype lzss0
get ZIP byte    # 1
get ZSIZE long
get SIZE long
savepos OFFSET
get NAME basename
clog NAME OFFSET ZSIZE SIZE

Compress script:

Code:

comtype lzss0_compress
get SIZE asize
log MEMORY_FILE 0 0
put 1 byte MEMORY_FILE
put 0 long MEMORY_FILE
put SIZE long MEMORY_FILE
savepos OFFSET MEMORY_FILE
append
clog MEMORY_FILE 0 SIZE SIZE
append
get ZSIZE asize MEMORY_FILE
math ZSIZE - OFFSET
goto 1 MEMORY_FILE
put ZSIZE long MEMORY_FILE
get SIZE asize MEMORY_FILE
get NAME basename
log NAME 0 SIZE MEMORY_FILE