import hashlib import io import os import struct from PIL import Image # type: ignore from typing import Dict, List, Tuple from bemani.protocol.binary import BinaryEncoding from bemani.protocol.xml import XmlEncoding from bemani.protocol.lz77 import Lz77 from bemani.protocol.node import Node class IFS: """ Best-effort utility for decoding the `.ifs` file format. There are better tools out there, but this was developed before their existence. This should work with most of the games out there including non-rhythm games that use this format. """ def __init__(self, data: bytes, decode_binxml: bool=False, decode_textures: bool=False) -> None: self.__files: Dict[str, bytes] = {} self.__formats: Dict[str, str] = {} self.__compressed: Dict[str, bool] = {} self.__imgsize: Dict[str, Tuple[int, int, int, int]] = {} self.__uvsize: Dict[str, Tuple[int, int, int, int]] = {} self.__decode_binxml = decode_binxml self.__decode_textures = decode_textures self.__parse_file(data) def __fix_name(self, filename: str) -> str: if filename[0] == '_' and filename[1].isdigit(): filename = filename[1:] filename = filename.replace('_E', '.') filename = filename.replace('__', '_') return filename def __parse_file(self, data: bytes) -> None: # Grab the magic values and make sure this is an IFS (signature, version, version_crc, pack_time, unpacked_header_size, data_index) = struct.unpack( '>IHHIII', data[0:20], ) if signature != 0x6CAD8F89: raise Exception('Invalid IFS file!') if version ^ version_crc != 0xFFFF: raise Exception('Corrupt version in IFS file!') if version == 1: # No header MD5 header_offset = 20 else: # Make room for header MD5, at byte offset 20-36 header_offset = 36 # First, try as binary benc = BinaryEncoding() header = benc.decode(data[header_offset:data_index]) if header is None: # Now, try as XML xenc = XmlEncoding() header = xenc.decode( b'' + data[header_offset:data_index].split(b'\0')[0] ) if header is None: raise Exception('Invalid IFS file!') files: Dict[str, Tuple[int, int, int]] = {} if header.name != 'imgfs': raise Exception('Unknown IFS format!') def get_children(parent: str, node: Node) -> None: real_name = self.__fix_name(node.name) if node.data_type == '3s32': node_name = os.path.join(parent, real_name).replace('/imgfs/', '') files[node_name] = (node.value[0] + data_index, node.value[1], node.value[2]) else: for subchild in node.children: get_children(os.path.join(parent, f"{real_name}/"), subchild) # Recursively walk the entire filesystem extracting files and their locations. get_children("/", header) for fn in files: (start, size, pack_time) = files[fn] filedata = data[start:(start + size)] self.__files[fn] = filedata # Now, find all of the index files that are available. for filename in list(self.__files.keys()): abs_filename = ("/" if filename.startswith("/") else "") + filename if abs_filename.endswith("/texturelist.xml"): # This is a texture index. texdir = os.path.dirname(filename) benc = BinaryEncoding() texdata = benc.decode(self.__files[filename]) if texdata.name != 'texturelist': raise Exception(f"Unexpected name {texdata.name} in texture list!") if texdata.attribute('compress') == 'avslz': compressed = True else: compressed = False for child in texdata.children: if child.name != 'texture': continue textfmt = child.attribute('format') for subchild in child.children: if subchild.name != 'image': continue md5sum = hashlib.md5(subchild.attribute('name').encode(benc.encoding)).hexdigest() oldname = os.path.join(texdir, md5sum) newname = os.path.join(texdir, subchild.attribute('name')) if oldname in self.__files: supported = False if self.__decode_textures: if textfmt in ["argb8888rev"]: # This is a supported file to decode newname += ".png" supported = True # Remove old index, update file to new index. self.__files[newname] = self.__files[oldname] del self.__files[oldname] # Remember the attributes for this file so we can extract it later. self.__compressed[newname] = compressed if supported: # Only pop down the format and sizes if we support extracting. self.__formats[newname] = textfmt rect = subchild.child_value('imgrect') if rect is not None: self.__imgsize[newname] = ( rect[0] // 2, rect[1] // 2, rect[2] // 2, rect[3] // 2, ) rect = subchild.child_value('uvrect') if rect is not None: self.__uvsize[newname] = ( rect[0] // 2, rect[1] // 2, rect[2] // 2, rect[3] // 2, ) elif abs_filename.endswith("/afplist.xml"): # This is a texture index. afpdir = os.path.dirname(filename) bsidir = os.path.join(afpdir, "bsi") geodir = os.path.join(os.path.dirname(afpdir), "geo") benc = BinaryEncoding() afpdata = benc.decode(self.__files[filename]) if afpdata.name != 'afplist': raise Exception(f"Unexpected name {afpdata.name} in afp list!") for child in afpdata.children: if child.name != 'afp': continue # First, fix up the afp files themselves. name = child.attribute('name') md5sum = hashlib.md5(name.encode(benc.encoding)).hexdigest() for fixdir in [afpdir, bsidir]: oldname = os.path.join(fixdir, md5sum) newname = os.path.join(fixdir, name) if oldname in self.__files: # Remove old index, update file to new index. self.__files[newname] = self.__files[oldname] del self.__files[oldname] # Now, fix up the shape files as well. geodata = child.child_value("geo") if geodata is not None: for geoid in geodata: geoname = f"{name}_shape{geoid}" md5sum = hashlib.md5(geoname.encode(benc.encoding)).hexdigest() oldname = os.path.join(geodir, md5sum) newname = os.path.join(geodir, geoname) if oldname in self.__files: # Remove old index, update file to new index. self.__files[newname] = self.__files[oldname] del self.__files[oldname] @property def filenames(self) -> List[str]: return [f for f in self.__files] def read_file(self, filename: str) -> bytes: # First, figure out if this file is stored compressed or not. If it is, decompress # it so that we have the raw data available to us. decompress = self.__compressed.get(filename, False) filedata = self.__files[filename] if decompress: uncompressed_size, compressed_size = struct.unpack('>II', filedata[0:8]) if len(filedata) == compressed_size + 8: lz77 = Lz77() filedata = lz77.decompress(filedata[8:]) else: raise Exception('Unrecognized compression!') if self.__decode_binxml and os.path.splitext(filename)[1] == '.xml': benc = BinaryEncoding() filexml = benc.decode(filedata) if filexml is not None: filedata = str(filexml).encode('utf-8') if self.__decode_textures and filename in self.__formats and filename in self.__imgsize and filename in self.__uvsize: fmt = self.__formats[filename] img = self.__imgsize[filename] crop = self.__uvsize[filename] # Decode the image data itself. if fmt == "argb8888rev": width = img[1] - img[0] height = img[3] - img[2] if len(filedata) < (width * height * 4): left = (width * height * 4) - len(filedata) filedata = filedata + b'\x00' * left png = Image.frombytes('RGBA', (width, height), filedata, 'raw', 'BGRA') png = png.crop(( crop[0] - img[0], crop[2] - img[2], crop[1] - img[0], crop[3] - img[2], )) b = io.BytesIO() png.save(b, format='PNG') filedata = b.getvalue() return filedata