This is a plaintext description of the format:
// file is the "entry" point
[file]
0: u32 - header length
1: bytearray($0) - header
2: u32 - number of files in archive
n: dir - directory listing
[dir]
0: u32 - filename length
1: bytearray($0) - filename
2: u32 - file offset
3: u32 - file size
It's a simple format. A python script to extract it is included below.
| import argparse | |
| from pathlib import Path | |
| # read little endian unsigned 32 bit integer | |
| readLEU32 = lambda f: int.from_bytes(f.read(4), byteorder='little', signed=False) | |
| class DirInfo: | |
| """A class that contains metadata for a file""" | |
| def __init__(self, f): | |
| dir_name_len = readLEU32(f) | |
| self.name = f.read(dir_name_len).decode('utf-8') | |
| self.offset = readLEU32(f) | |
| self.size = readLEU32(f) | |
| def __repr__(self): | |
| return pprint.saferepr(self.__dict__) | |
| class Archive: | |
| """A class that contains metadata for the whole file""" | |
| def __init__(self, filename, f): | |
| self.file = filename | |
| header_len = readLEU32(f) | |
| self.header = f.read(header_len).decode('utf-8') | |
| self.dir_size = readLEU32(f) | |
| self.contents = [DirInfo(f) for i in range(self.dir_size)] | |
| self.metaend = f.tell() | |
| def __repr__(self): | |
| return pprint.saferepr(self.__dict__) | |
| def read_meta(input_file_path): | |
| """Read metadata from file""" | |
| input_file = Path(input_file_path) | |
| with input_file.open('rb') as f: | |
| return Archive(input_file, f) | |
| def dump_file(meta, output_path): | |
| """Dump the archive into output_path""" | |
| output = Path(output_path) | |
| if output.exists() and not output.is_dir(): | |
| raise ValueError('Output directory cannot be created') | |
| with meta.file.open('rb') as f: | |
| for directory in meta.contents: | |
| output_file_path = output / directory.name | |
| output_file_path.parent.mkdir(parents=True, exist_ok=True) | |
| f.seek(meta.metaend + directory.offset) | |
| output_file_path.write_bytes(f.read(directory.size)) | |
| def main(): | |
| """main function""" | |
| parser = argparse.ArgumentParser(description='Dumps Wallpaper Engine pkg file into a directory. Supports PKGV0009 only.') | |
| parser.add_argument('input_file') | |
| parser.add_argument('output_path') | |
| args = parser.parse_args() | |
| archive = read_meta(args.input_file) | |
| dump_file(archive, args.output_path) | |
| if __name__ == '__main__': | |
| main() |