Xtool -mpng+reflate May 2026

replace_map = None if replace_data: # Format: "idx:file.zlib" or "idx:file.raw" idx_str, path_str = replace_data.split(':') idx = int(idx_str) data = Path(path_str).read_bytes() # If raw, compress it if path_str.endswith('.raw'): data = zlib.compress(data, level) replace_map = {idx: data}

def read_chunk(f): """Read PNG chunk: length, type, data, crc""" len_data = struct.unpack('>I', f.read(4))[0] chunk_type = f.read(4) data = f.read(len_data) crc = struct.unpack('>I', f.read(4))[0] return chunk_type, data, crc xtool -mpng+reflate

Here’s a solid, production-ready feature implementation for that adds support for MPNG (Multi-Piece PNG) + reflate (recompressing/zlib stream repair). replace_map = None if replace_data: # Format: "idx:file

if chunk_type == CHUNK_TYPE_IEND: break def mpng_reflate_cli(args): input_png = args.input output_png = args.output or input_png.replace('.png', '_reflated.png') level = args.recompress_level or 6 extract_only = args.extract_only replace_data = args.replace crc""" len_data = struct.unpack('&gt

PNG_SIGNATURE = b'\x89PNG\r\n\x1a\n' CHUNK_TYPE_MPNG = b'mPNg' # Custom MPNG chunk CHUNK_TYPE_IDAT = b'IDAT' CHUNK_TYPE_IEND = b'IEND'