Corpse Party 2: Dead Patient BGM PAK files

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
centauri
Posts: 2
Joined: Mon Apr 27, 2020 7:40 pm

Corpse Party 2: Dead Patient BGM PAK files

Post by centauri »

Hi, I'm new here!
I've been trying to do some research trying to find a way to extract Corpse Party 2 music, but it seems they use some kind of specific PAK file which I cannot find a way to extract with my ultra limited knowledge.

Opening them on HxD Editor to check the header, seems like they all have this "fact" and ".data" hex value near the start of the file
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I attached here some example files of different sizes. Hope they are useful
If anyone needs more files or anything specific, I'll do it as soon as I can :D
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: Corpse Party 2: Dead Patient BGM PAK files

Post by aluigi »

Each pak contains just one wav audio file at offset 5.
Do you have other non-bgm pak files for analysis?
centauri
Posts: 2
Joined: Mon Apr 27, 2020 7:40 pm

Re: Corpse Party 2: Dead Patient BGM PAK files

Post by centauri »

aluigi wrote:Each pak contains just one wav audio file at offset 5.
Do you have other non-bgm pak files for analysis?

sorry for taking long to respond, was busy with work.
Here are some different pak files that are scattered through the game files, I took 1 of 3 different folders... CG, SE, and what i suppose is the voice line folder.
Interestingly most of the game is mostly uncompressed and unencrypted except this files and some scripts in .dat format
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: Corpse Party 2: Dead Patient BGM PAK files

Post by aluigi »

I confirm that they are all the same container:

Code: Select all

# Corpse Party 2: Dead Patient PAK

math OFFSET = 5
get SIZE asize
math SIZE - OFFSET
get NAME basename
string NAME + .
log NAME OFFSET SIZE