Xtool -mpng+reflate Access
while True: chunk_type, data, _ = read_chunk(f) if chunk_type == CHUNK_TYPE_MPNG: # MPNG chunk structure: [index:4][compressed_data...] idx = struct.unpack('>I', data[:4])[0] compressed = data[4:] streams.append((idx, compressed)) elif chunk_type == CHUNK_TYPE_IEND: break return streams def reflate_stream(compressed_data, level=6, extract_only=False): """Reflate: decompress then recompress zlib stream""" decompressed = zlib.decompress(compressed_data) if extract_only: return decompressed # raw decompressed data recompressed = zlib.compress(decompressed, level) return recompressed
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
streams = extract_mpng_streams(input_png) if not streams: print("No MPNG chunks found.") return while True: chunk_type, data, _ = read_chunk(f) if