def test_window_length(self):
X = stft(self.x, 512, 160, window_length=400)
x_hat = istft(X, 512, 160, window_length=400)
X_ref = istft(stft(self.x, 400, 160), 400, 160)
tc.assert_equal(X.shape, (243, 257))
tc.assert_allclose(X_ref, x_hat, rtol=1e-6, atol=1e-6)
def test_compare_both_biorthogonal_window_variants(self):
window = signal.blackman(1024)
shift = 256
for_result = _biorthogonal_window_loopy(window, shift)
vec_result = _biorthogonal_window(window, shift)
brute_force_result = _biorthogonal_window_brute_force(window, shift)
tc.assert_equal(for_result, vec_result)
tc.assert_allclose(for_result, brute_force_result)
tc.assert_equal(for_result.shape, (1024, ))
def test_biorthogonal_window_inverts_analysis_window_kaldi_parameter(self):
from paderbox.array import roll_zeropad
def inf_shift_add(analysis_window, shift):
influence_width = ((len(analysis_window) - 1) // shift)
influence_width *= 2 # be sure that it is high enough
res = np.zeros_like(analysis_window)
for i in range(-influence_width, influence_width + 1):
res += roll_zeropad(analysis_window, shift * i)
return res
window = signal.blackman(400)
shift = 160
synthesis_window = _biorthogonal_window_brute_force(window, shift)
s = inf_shift_add(window * synthesis_window, shift)
tc.assert_allclose(s, 1)
def test_center_frequencies(self):
tc.assert_allclose(
get_stft_center_frequencies(size=1024, sample_rate=16000)[0], 0)