def test_apply_pitch_shift(self):
samples = np.zeros((512,), dtype=np.float32)
sample_rate = 16000
augmenter = Compose([PitchShift(min_semitones=-2, max_semitones=-1, p=1.0)])
samples = augmenter(samples=samples, sample_rate=sample_rate)
self.assertEqual(samples.dtype, np.float32)
self.assertEqual(len(samples), 512)
def test_apply_pitch_shift_multichannel(self):
num_channels = 3
samples = np.random.normal(0, 0.1, size=(num_channels, 5555)).astype(np.float32)
sample_rate = 16000
augmenter = Compose([PitchShift(min_semitones=1, max_semitones=2, p=1.0)])
samples_out = augmenter(samples=samples, sample_rate=sample_rate)
self.assertEqual(samples_out.dtype, np.float32)
self.assertEqual(samples_out.shape, samples.shape)
for i in range(num_channels):
assert not np.allclose(samples[i], samples_out[i])
def test_freeze_parameters(self):
"""
Test that the transform can freeze its parameters, e.g. to apply the effect with the
same parameters to multiple sounds.
"""
samples = np.sin(np.linspace(0, 440 * 2 * np.pi, 8000)).astype(np.float32)
sample_rate = 16000
augmenter = Compose([PitchShift(min_semitones=1, max_semitones=12, p=1.0)])
first_samples = augmenter(samples=samples, sample_rate=sample_rate)
first_parameters = deepcopy(augmenter.transforms[0].parameters)
augmenter.transforms[0].min_semitones = -12
augmenter.transforms[0].max_semitones = -1
augmenter.transforms[0].freeze_parameters = True
second_samples = augmenter(samples=samples, sample_rate=sample_rate)
self.assertEqual(first_parameters, augmenter.transforms[0].parameters)
assert_array_equal(first_samples, second_samples)