def test_embedding_cero(self):
quantizer = MagicMock(return_value=30)
emb = BinaryDM(quantizer, d0=5)
# positive d(m)
emb.dither = Mock(return_value=4)
self.assertEqual(emb.embed(25, 0), 26)
quantizer.assert_called_with(29)
self.assertListEqual(emb.dither.call_args_list, [call(0), call(0)])
# negative d(m)
emb.dither = Mock(return_value=-4)
self.assertEqual(emb.embed(25, 0), 34)
quantizer.assert_called_with(21)
self.assertListEqual(emb.dither.call_args_list, [call(0), call(0)])
def test_embedding_one(self):
quantizer = MagicMock(return_value=-30)
emb = BinaryDM(quantizer, d0=5)
# positive d(m)
emb.dither = Mock(return_value=4)
self.assertEqual(emb.embed(-25, 1), -34)
quantizer.assert_called_with(-21)
self.assertListEqual(emb.dither.call_args_list, [call(1), call(1)])
# negative d(m)
emb.dither = Mock(return_value=-4)
self.assertEqual(emb.embed(-25, 1), -26)
quantizer.assert_called_with(-29)
self.assertListEqual(emb.dither.call_args_list, [call(1), call(1)])
def test_zero_d0(self):
'''Test dither function for a positive d0'''
quantize = Mock(step=12)
emb = BinaryDM(quantize, d0=0)
self.assertEqual(emb.dither(0), 0)
self.assertEqual(emb.dither(1), -6)