def test_hifreqs(self):
# For those freq, downsample2 should return zero
for freq in [36, 40, 56, 64]:
x = pure_tone(freq, sr=128)
y = resample._downsample2(x)
y_gt = 0 * y
self.assertSimilar(y, y_gt, x, f"freq={freq}")
def test_lowfreqs(self):
# For those freq, downsample2 should be almost decimation
for freq in [8, 16, 20, 28]:
x = pure_tone(freq, sr=128)
y_gt = x[::2]
y = resample._downsample2(x)
self.assertSimilar(y, y_gt, x, f"freq={freq}")
def test_mixture(self):
# Test one mixture
x_low = pure_tone(16, sr=128)
x_high = pure_tone(40, sr=128)
x = x_low + x_high
y = resample._downsample2(x)
y_gt = x_low[::2]
self.assertSimilar(y, y_gt, x, "mixture")
def test_ref(self):
# Compare to _upsample2 and _downsample2
for freq in [8, 16, 20, 28, 32, 36, 40, 56, 64]:
x = pure_tone(freq, sr=128)
y_gt_down = resample._downsample2(x)
y_down = resample.resample_frac(x, 2, 1, rolloff=1)
self.assertSimilar(y_down, y_gt_down, x, f"freq={freq} down")
y_gt_up = resample._upsample2(x)
y_up = resample.resample_frac(x, 1, 2, rolloff=1)
self.assertSimilar(y_up, y_gt_up, x, f"freq={freq} up")