FTL.dat unpacker

unpack.py

from pathlib import Path
from typing import List

from binreader import BinaryReader


class PkgEntry:
    path_hash: int
    path_offset: int
    data_deflated: bool
    data_offset: int
    data_size: int
    data_unpacked_size: int

    def __str__(self):
        return f"hash: {self.path_hash}; offset: {self.path_offset}; deflated: {self.data_deflated}; data_offset: {self.data_offset}; data_size: {self.data_size}; data_unpacked_size: {self.data_unpacked_size}"


PKG_MAGIC = b"PKG\n"
ENTRIES: List[PkgEntry] = []


with open("ftl.dat", "rb") as f:
    reader = BinaryReader(f, ">")
    magic = reader.read(4)
    assert magic == PKG_MAGIC

    header_size = reader.read_uint16()
    assert header_size == 0x10, "Invalid Header Size"
    entry_size = reader.read_uint16()
    assert entry_size == 0x20, "Invalid Entry Size"
    entry_count = reader.read_uint32()
    paths_region_size = reader.read_uint32()

    i = 0
    while i < entry_count:
        entry = PkgEntry()
        entry.path_hash = reader.read_uint32()
        path_offset_and_flags = reader.read_uint32()
        entry.path_offset = path_offset_and_flags & 0x00FFFFFF
        entry.data_deflated = (path_offset_and_flags & (1 << 24)) != 0

        entry.data_offset = reader.read_uint32()
        entry.data_size = reader.read_uint32()
        entry.data_unpacked_size = reader.read_uint32()

        if entry.data_size == 0:
            ENTRIES.append(None)
            break
        else:
            ENTRIES.append(entry)
        i += 1

    path_region = reader.read(paths_region_size)

    for entry in ENTRIES:
        path = ""
        while True:
            c = path_region[entry.path_offset]
            entry.path_offset += 1
            if c == 0:
                break
            path += chr(c)

        print(f"Processing {path}")
        reader.seek(entry.data_offset)
        data = reader.read(entry.data_size)

        path = Path(path)
        path.parent.mkdir(parents=True, exist_ok=True)
        with open(path, "wb") as f:
            f.write(data)