def hide(self, bin_data, order_num=0, bad_bits_num=1):
bin_data = pack(">L", len(bin_data)) + bin_data
if len(bin_data) > self.container_space(bad_bits_num):
raise ContainerException("Too much data to hide. {}: but max={}".format(
len(bin_data), self.container_space())
)
order_inspector = ORDER_INSPECTORS[order_num](self.container_space())
sample_id = 0
pos = 0
hidden_data_byte = 0
bits_data = byte_tools.to_bits(bin_data)
for i in range(len(bits_data)):
hidden_data_byte = hidden_data_byte * 2 + bits_data[i]
pos += 1
if (pos == bad_bits_num) or (i + 1 == len(bits_data)):
if i + 1 == len(bits_data) and not (pos == bad_bits_num):
while pos != bad_bits_num:
hidden_data_byte *= 2
pos += 1
self[sample_id] = byte_tools.hide_data(self[sample_id], hidden_data_byte, bad_bits_num)
pos = 0
hidden_data_byte = 0
sample_id = order_inspector.next()
def test_to_bits(self):
b = b'\xff\x01'
res = 0
for bit in byte_tools.to_bits(b):
res = res * 10 + bit
self.assertEqual(1111111100000001, res)
def test_to_bytes(self):
first = b'\xff\x01'
b = bytes(byte_tools.to_bytes(byte_tools.to_bits(first)))
self.assertEqual(first, b)
