def decompress(reader: MemoryViewReader,
signature: Signature) -> MemoryViewReader:
"""
Decompress the rest of an SWF file, depending on its signature.
"""
if signature == Signature.UNCOMPRESSED:
return reader
if signature == Signature.LZMA:
# https://stackoverflow.com/a/39777419/359730
reader.skip(4) # skip compressed length
return MemoryViewReader(
lzma.decompress(
reader.read(5).tobytes() +
b'\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF' +
reader.read_all().tobytes()))
if signature == Signature.ZLIB:
return MemoryViewReader(zlib.decompress(reader.read_all()))
assert False, 'unreachable code'
def __init__(self, raw: memoryview):
reader = MemoryViewReader(raw)
self.flags = DoABCTagFlags(reader.read_u32())
self.name = reader.read_string()
self.abc_file = reader.read_all()