code: def _get_header(self):
          
          fh = self._src
          obj = _make_object("Header")
  
          # first part of the header
          obj.Signature = sign = "".join(chr(unpack_ui8(fh)) for _ in range(3))
          obj.Version = self._version = unpack_ui8(fh)
          obj.FileLength = file_length = unpack_ui32(fh)
  
          # deal with compressed content
          if sign[0] == 'C':
              uncompressed = zlib.decompress(fh.read())
              if len(uncompressed) + 8 != file_length:
                  raise ValueError("Problems dealing with compressed content")
              fh = self._src = io.BytesIO(uncompressed)
  
          # second part of the header
          obj.FrameSize = self._get_struct_rect()
          obj.FrameRate = unpack_ui16(fh)
          obj.FrameCount = unpack_ui16(fh)
          return obj
docs: Parse the SWF header.