def test_default_windowsize(self):
num_samples = 1000
one_track = MonoAudioWave([1] * num_samples, 44000)
hanned = one_track.transform(HanningWindow())
for idx, value in enumerate(hanned.samples):
self.assertAlmostEqual(hanning(num_samples)[idx], value, places=2)
def test_rms_calculation(self):
sine_track = MonoAudioWave(np.sin(np.linspace(0, 1000, 10000)), 44000)
# Full-scale sine has -3db RMS
self.assertAlmostEqual(sine_track.get_rms(), -3, places=1)
# Half signal is a 6dB decrease
sine_track.samples = sine_track.samples / 2
self.assertAlmostEqual(sine_track.get_rms(), -9, places=1)
def test_peak_from_below(self):
sine_track = MonoAudioWave(np.sin(np.linspace(0, 1000, 10000)), 44000)
# Normalized initialization
self.assertAlmostEqual(max(abs(sine_track.samples)), 1, places=1)
# Reduce to half-scale
sine_track.samples /= 2
self.assertAlmostEqual(max(abs(sine_track.samples)), 0.5, places=1)
# Normalize again
sine_track = sine_track.transform(PeakNormalizer())
self.assertAlmostEqual(max(abs(sine_track.samples)), 1, places=1)
def test_peak_from_above(self):
sine_track = MonoAudioWave(np.sin(np.linspace(0, 1000, 10000)), 44000)
# Normalized initialization
self.assertAlmostEqual(max(abs(sine_track.samples)), 1, places=1)
# Amplify to double-cale
sine_track.samples = sine_track.samples * 2
self.assertAlmostEqual(max(abs(sine_track.samples)), 2, places=1)
# Normalize again
sine_track = sine_track.transform(PeakNormalizer())
self.assertAlmostEqual(max(abs(sine_track.samples)), 1, places=1)
def __call__(self, data: MonoAudioWave) -> MonoAudioWave:
assert isinstance(data, MonoAudioWave)
if self.rampup_time is None:
rampup_samples = data.num_samples // 2
else:
rampup_samples = data.get_sample_id(self.rampup_time)
if self.rampdown_time is None:
rampdown_samples = data.num_samples // 2
else:
rampdown_samples = data.get_sample_id(self.rampdown_time)
rampup_window = self._window(rampup_samples * 2)[:rampup_samples]
rampdown_window = self._window(rampdown_samples * 2)[:rampdown_samples]
data.samples[:rampup_samples] = rampup_window \
* data.samples[:rampup_samples]
data.samples[-rampdown_samples:] = rampdown_window[::-1] * \
data.samples[-rampdown_samples:]
return data
def test_peak_from_above(self):
sine_track = MonoAudioWave(np.sin(np.linspace(0, 1000, 10000)), 44000)
# Normalize to 3dB -> factor 2 amplitude increase
sine_track = sine_track.transform(RmsNormalizer(2))
self.assertAlmostEqual(rms(sine_track.samples), 2, places=1)
def test_rms_from_above(self):
sine_track = MonoAudioWave(np.sin(np.linspace(0, 1000, 10000)), 44000)
sine_track = sine_track.transform(RmsNormalizer(0.5))
self.assertAlmostEqual(rms(sine_track.samples), 0.5, places=1)
def __call__(self, data: MonoAudioWave) -> MonoAudioWave:
assert isinstance(data, MonoAudioWave)
data.samples = data.samples / np.max(np.abs(data.samples))
return data