def pack_2to3(self, inp):
"""
converts 2 12bit integers to 3 8bit integers
output bytes: 00000000 00001111 11111111
"""
if len(inp) != 2:
logger.error("Input to pack_2to3 should have 2 elements.")
return []
inp = [value & 4095 for value in inp]
return [inp[0] >> 4, (inp[0] << 4) & 255 | inp[1] >> 8, inp[1] & 255]
def pack_4to3(self, inp):
"""
converts 4 6bit integers to 3 8bit integers
output bytes: 00000011 11112222 22333333
"""
if len(inp) != 4:
logger.error("Input to pack_4to3 should have 4 elements.")
return []
inp = [value & 63 for value in inp]
return [(inp[0] << 2) & 255 | inp[1] >> 4, (inp[1] << 4) & 255 | inp[2] >> 2, (inp[2] << 6) & 255 | inp[3]]
