| # Copyright (c) 2017 The WebRTC project authors. All Rights Reserved. |
| # |
| # Use of this source code is governed by a BSD-style license |
| # that can be found in the LICENSE file in the root of the source |
| # tree. An additional intellectual property rights grant can be found |
| # in the file PATENTS. All contributing project authors may |
| # be found in the AUTHORS file in the root of the source tree. |
| """Unit tests for the signal_processing module. |
| """ |
| |
| import unittest |
| |
| import numpy as np |
| import pydub |
| |
| from . import exceptions |
| from . import signal_processing |
| |
| |
| class TestSignalProcessing(unittest.TestCase): |
| """Unit tests for the signal_processing module. |
| """ |
| |
| def testMixSignals(self): |
| # Generate a template signal with which white noise can be generated. |
| silence = pydub.AudioSegment.silent(duration=1000, frame_rate=48000) |
| |
| # Generate two distinct AudioSegment instances with 1 second of white noise. |
| signal = signal_processing.SignalProcessingUtils.GenerateWhiteNoise( |
| silence) |
| noise = signal_processing.SignalProcessingUtils.GenerateWhiteNoise( |
| silence) |
| |
| # Extract samples. |
| signal_samples = signal.get_array_of_samples() |
| noise_samples = noise.get_array_of_samples() |
| |
| # Test target SNR -Inf (noise expected). |
| mix_neg_inf = signal_processing.SignalProcessingUtils.MixSignals( |
| signal, noise, -np.Inf) |
| self.assertTrue(len(noise), len(mix_neg_inf)) # Check duration. |
| mix_neg_inf_samples = mix_neg_inf.get_array_of_samples() |
| self.assertTrue( # Check samples. |
| all([x == y for x, y in zip(noise_samples, mix_neg_inf_samples)])) |
| |
| # Test target SNR 0.0 (different data expected). |
| mix_0 = signal_processing.SignalProcessingUtils.MixSignals( |
| signal, noise, 0.0) |
| self.assertTrue(len(signal), len(mix_0)) # Check duration. |
| self.assertTrue(len(noise), len(mix_0)) |
| mix_0_samples = mix_0.get_array_of_samples() |
| self.assertTrue( |
| any([x != y for x, y in zip(signal_samples, mix_0_samples)])) |
| self.assertTrue( |
| any([x != y for x, y in zip(noise_samples, mix_0_samples)])) |
| |
| # Test target SNR +Inf (signal expected). |
| mix_pos_inf = signal_processing.SignalProcessingUtils.MixSignals( |
| signal, noise, np.Inf) |
| self.assertTrue(len(signal), len(mix_pos_inf)) # Check duration. |
| mix_pos_inf_samples = mix_pos_inf.get_array_of_samples() |
| self.assertTrue( # Check samples. |
| all([x == y for x, y in zip(signal_samples, mix_pos_inf_samples)])) |
| |
| def testMixSignalsMinInfPower(self): |
| silence = pydub.AudioSegment.silent(duration=1000, frame_rate=48000) |
| signal = signal_processing.SignalProcessingUtils.GenerateWhiteNoise( |
| silence) |
| |
| with self.assertRaises(exceptions.SignalProcessingException): |
| _ = signal_processing.SignalProcessingUtils.MixSignals( |
| signal, silence, 0.0) |
| |
| with self.assertRaises(exceptions.SignalProcessingException): |
| _ = signal_processing.SignalProcessingUtils.MixSignals( |
| silence, signal, 0.0) |
| |
| def testMixSignalNoiseDifferentLengths(self): |
| # Test signals. |
| shorter = signal_processing.SignalProcessingUtils.GenerateWhiteNoise( |
| pydub.AudioSegment.silent(duration=1000, frame_rate=8000)) |
| longer = signal_processing.SignalProcessingUtils.GenerateWhiteNoise( |
| pydub.AudioSegment.silent(duration=2000, frame_rate=8000)) |
| |
| # When the signal is shorter than the noise, the mix length always equals |
| # that of the signal regardless of whether padding is applied. |
| # No noise padding, length of signal less than that of noise. |
| mix = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=shorter, |
| noise=longer, |
| pad_noise=signal_processing.SignalProcessingUtils.MixPadding. |
| NO_PADDING) |
| self.assertEqual(len(shorter), len(mix)) |
| # With noise padding, length of signal less than that of noise. |
| mix = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=shorter, |
| noise=longer, |
| pad_noise=signal_processing.SignalProcessingUtils.MixPadding. |
| ZERO_PADDING) |
| self.assertEqual(len(shorter), len(mix)) |
| |
| # When the signal is longer than the noise, the mix length depends on |
| # whether padding is applied. |
| # No noise padding, length of signal greater than that of noise. |
| mix = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=longer, |
| noise=shorter, |
| pad_noise=signal_processing.SignalProcessingUtils.MixPadding. |
| NO_PADDING) |
| self.assertEqual(len(shorter), len(mix)) |
| # With noise padding, length of signal greater than that of noise. |
| mix = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=longer, |
| noise=shorter, |
| pad_noise=signal_processing.SignalProcessingUtils.MixPadding. |
| ZERO_PADDING) |
| self.assertEqual(len(longer), len(mix)) |
| |
| def testMixSignalNoisePaddingTypes(self): |
| # Test signals. |
| shorter = signal_processing.SignalProcessingUtils.GenerateWhiteNoise( |
| pydub.AudioSegment.silent(duration=1000, frame_rate=8000)) |
| longer = signal_processing.SignalProcessingUtils.GeneratePureTone( |
| pydub.AudioSegment.silent(duration=2000, frame_rate=8000), 440.0) |
| |
| # Zero padding: expect pure tone only in 1-2s. |
| mix_zero_pad = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=longer, |
| noise=shorter, |
| target_snr=-6, |
| pad_noise=signal_processing.SignalProcessingUtils.MixPadding. |
| ZERO_PADDING) |
| |
| # Loop: expect pure tone plus noise in 1-2s. |
| mix_loop = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=longer, |
| noise=shorter, |
| target_snr=-6, |
| pad_noise=signal_processing.SignalProcessingUtils.MixPadding.LOOP) |
| |
| def Energy(signal): |
| samples = signal_processing.SignalProcessingUtils.AudioSegmentToRawData( |
| signal).astype(np.float32) |
| return np.sum(samples * samples) |
| |
| e_mix_zero_pad = Energy(mix_zero_pad[-1000:]) |
| e_mix_loop = Energy(mix_loop[-1000:]) |
| self.assertLess(0, e_mix_zero_pad) |
| self.assertLess(e_mix_zero_pad, e_mix_loop) |
| |
| def testMixSignalSnr(self): |
| # Test signals. |
| tone_low = signal_processing.SignalProcessingUtils.GeneratePureTone( |
| pydub.AudioSegment.silent(duration=64, frame_rate=8000), 250.0) |
| tone_high = signal_processing.SignalProcessingUtils.GeneratePureTone( |
| pydub.AudioSegment.silent(duration=64, frame_rate=8000), 3000.0) |
| |
| def ToneAmplitudes(mix): |
| """Returns the amplitude of the coefficients #16 and #192, which |
| correspond to the tones at 250 and 3k Hz respectively.""" |
| mix_fft = np.absolute( |
| signal_processing.SignalProcessingUtils.Fft(mix)) |
| return mix_fft[16], mix_fft[192] |
| |
| mix = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=tone_low, noise=tone_high, target_snr=-6) |
| ampl_low, ampl_high = ToneAmplitudes(mix) |
| self.assertLess(ampl_low, ampl_high) |
| |
| mix = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=tone_high, noise=tone_low, target_snr=-6) |
| ampl_low, ampl_high = ToneAmplitudes(mix) |
| self.assertLess(ampl_high, ampl_low) |
| |
| mix = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=tone_low, noise=tone_high, target_snr=6) |
| ampl_low, ampl_high = ToneAmplitudes(mix) |
| self.assertLess(ampl_high, ampl_low) |
| |
| mix = signal_processing.SignalProcessingUtils.MixSignals( |
| signal=tone_high, noise=tone_low, target_snr=6) |
| ampl_low, ampl_high = ToneAmplitudes(mix) |
| self.assertLess(ampl_low, ampl_high) |
