Unpacker for Alice in Cyberland "ALICE.PAC" (Playstation)

alice_unpack.py

"""Unpacker for Alice in Cyberland "ALICE.PAC" (Playstation)"""

import argparse
import dataclasses
import struct
from typing import BinaryIO


# ALICE.PAC archive format:
#   File info table
#     (name, offset, length)
#     (0, 0, 0) -- terminator
#   File data


@dataclasses.dataclass
class FileRecord:
    name: str
    offset: int
    length: int


parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('file', type=argparse.FileType('rb'), help='PAC file to be unpacked')

args = parser.parse_args()
pac_file: BinaryIO = args.file
files_info: list[FileRecord] = []
while True:
    name_bytes, offset, length = struct.unpack('<12sLL', pac_file.read(20))
    name = name_bytes.rstrip(b'\0').decode()
    if not name:
        break

    files_info.append(FileRecord(name=name, offset=offset, length=length))

# extract all files
for f in files_info:
    pac_file.seek(f.offset)
    data = pac_file.read(f.length)

    with open(f.name, 'wb') as out_file:
        out_file.write(data)