def loadBbm(filename):
	""" Parse a bbm file and return an Animation object. """

	def getint16(vals):
		return (cals[2]>>8) + vals[3]
	def getint32(vals):
		return (vals[0]>>24) + (vals[1]>>16) + (cals[2]>>8) + vals[3]

	f = open(filename, 'r')
	rawdata = f.read()
	f.close()

	data = [ ord(x) for x in rawdata ]

	if getint32(data[0:4]) != 0x23542666:
		raise ValueError('magic does not match')

	height = getint16(data[4:6])
	width = getint16(data[6:8])
	channels = getint16(data[8:10])
	maxval = getint16(data[10:12])

	framecnt = getint32(data[10:14])
	duration = getint32(data[14:18])
	frameptr = getint32(data[18:22])

	# TODO: parse additional headers

	if rawdata[frameptr:(frameptr+4)] != 'frms':
		raise ValueError('frame pointer does not point to frame start marker')

	framedata = data[frameptr + 4:]
	framesize = width*height*channels

	frames = []
	while True:
		pass

	raise Exception('uarrgh!!')