$ python j2a-extract.py
Please type the filename of the .j2a file you wish to extract:
Anims.j2a
Traceback (most recent call last):
  File "j2a-extract.py", line 40, in 
    main()
  File "j2a-extract.py", line 9, in main
    j2a.read_header()
  File "censored/j2a.py", line 54, in read_header
    offset = struct.unpack("L", self.j2afile[self._headersize+(i*4):self._headersize+(i*4)+4])[0]
struct.error: unpack requires a string argument of length 8