Ace Attorney Pachislot unknown binaries inside CRI CPK

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
Slavfox
Posts: 2
Joined: Tue Jan 14, 2020 11:23 am

Ace Attorney Pachislot unknown binaries inside CRI CPK

Post by Slavfox »

Hi,

I'm trying to get the models from the Android Ace Attorney Pachislot game by Commseed.

The game seems to be using CRI formats - the .obb is a CPK containing a lot of .png images, some AWB archives with HCA sound files, and a couple distinct sets of binaries I don't know the format of.
One set starts with

Code: Select all

00 00 00 00
, the other starts with

Code: Select all

01 00 00 00
.

The all-zero-header files look like compressed data, with pretty high entropy, save for a small repeated section at the end, and no runs of zeroes. The 01... files seem a bit more structured.

If you have any idea what they could be, I'd appreciate any and all help I can get. I've attached a couple samples, the filenames are prefixed by the first 8 octets of their contents in hex.
LokiReborn
Posts: 190
Joined: Fri Aug 26, 2016 3:11 pm

Re: Ace Attorney Pachislot unknown binaries inside CRI CPK

Post by LokiReborn »

Looking fast the first 12 bytes either appear to be flags / ids for something in the game, 8 ~ 11 might be length / height or something for a painted area can't tell with out looking at the compressed data.
As for the compressed data itself at 0x0C it's zlib, so you'll need to decompress it before you know what's really in these, that's the same for all of the files you posted.
Slavfox
Posts: 2
Joined: Tue Jan 14, 2020 11:23 am

Re: Ace Attorney Pachislot unknown binaries inside CRI CPK

Post by Slavfox »

Thanks, I don't know how I missed that; it was in fact zlib.

I'm at a complete loss what the compressed data might be, though. All of them are files padded to a power-of-two filesize with the sequence

Code: Select all

00 00 00 02 FF FF FF FF
, interspersed with regular, low-entropy pairs of eight-byte sequences of... some kind of data. The regularity made me think they were images, at first, but I'm pretty sure they're not.