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/*
* Copyright (c) 2018 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.
*/
#include "modules/audio_processing/agc2/rnn_vad/spectral_features.h"
#include <algorithm>
#include "modules/audio_processing/agc2/rnn_vad/test_utils.h"
#include "rtc_base/checks.h"
#include "rtc_base/numerics/safe_compare.h"
// TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
// #include "test/fpe_observer.h"
#include "test/gtest.h"
namespace webrtc {
namespace rnn_vad {
namespace {
constexpr int kTestFeatureVectorSize = kNumBands + 3 * kNumLowerBands + 1;
// Writes non-zero sample values.
void WriteTestData(rtc::ArrayView<float> samples) {
for (int i = 0; rtc::SafeLt(i, samples.size()); ++i) {
samples[i] = i % 100;
}
}
rtc::ArrayView<float, kNumBands - kNumLowerBands> GetHigherBandsSpectrum(
std::array<float, kTestFeatureVectorSize>* feature_vector) {
return {feature_vector->data() + kNumLowerBands, kNumBands - kNumLowerBands};
}
rtc::ArrayView<float, kNumLowerBands> GetAverage(
std::array<float, kTestFeatureVectorSize>* feature_vector) {
return {feature_vector->data(), kNumLowerBands};
}
rtc::ArrayView<float, kNumLowerBands> GetFirstDerivative(
std::array<float, kTestFeatureVectorSize>* feature_vector) {
return {feature_vector->data() + kNumBands, kNumLowerBands};
}
rtc::ArrayView<float, kNumLowerBands> GetSecondDerivative(
std::array<float, kTestFeatureVectorSize>* feature_vector) {
return {feature_vector->data() + kNumBands + kNumLowerBands, kNumLowerBands};
}
rtc::ArrayView<float, kNumLowerBands> GetCepstralCrossCorrelation(
std::array<float, kTestFeatureVectorSize>* feature_vector) {
return {feature_vector->data() + kNumBands + 2 * kNumLowerBands,
kNumLowerBands};
}
float* GetCepstralVariability(
std::array<float, kTestFeatureVectorSize>* feature_vector) {
return feature_vector->data() + kNumBands + 3 * kNumLowerBands;
}
constexpr float kInitialFeatureVal = -9999.f;
// Checks that silence is detected when the input signal is 0 and that the
// feature vector is written only if the input signal is not tagged as silence.
TEST(RnnVadTest, SpectralFeaturesWithAndWithoutSilence) {
// Initialize.
SpectralFeaturesExtractor sfe;
std::array<float, kFrameSize20ms24kHz> samples;
rtc::ArrayView<float, kFrameSize20ms24kHz> samples_view(samples);
bool is_silence;
std::array<float, kTestFeatureVectorSize> feature_vector;
// Write an initial value in the feature vector to detect changes.
std::fill(feature_vector.begin(), feature_vector.end(), kInitialFeatureVal);
// TODO(bugs.webrtc.org/8948): Add when the issue is fixed.
// FloatingPointExceptionObserver fpe_observer;
// With silence.
std::fill(samples.begin(), samples.end(), 0.f);
is_silence = sfe.CheckSilenceComputeFeatures(
samples_view, samples_view, GetHigherBandsSpectrum(&feature_vector),
GetAverage(&feature_vector), GetFirstDerivative(&feature_vector),
GetSecondDerivative(&feature_vector),
GetCepstralCrossCorrelation(&feature_vector),
GetCepstralVariability(&feature_vector));
// Silence is expected, the output won't be overwritten.
EXPECT_TRUE(is_silence);
EXPECT_TRUE(std::all_of(feature_vector.begin(), feature_vector.end(),
[](float x) { return x == kInitialFeatureVal; }));
// With no silence.
WriteTestData(samples);
is_silence = sfe.CheckSilenceComputeFeatures(
samples_view, samples_view, GetHigherBandsSpectrum(&feature_vector),
GetAverage(&feature_vector), GetFirstDerivative(&feature_vector),
GetSecondDerivative(&feature_vector),
GetCepstralCrossCorrelation(&feature_vector),
GetCepstralVariability(&feature_vector));
// Silence is not expected, the output will be overwritten.
EXPECT_FALSE(is_silence);
EXPECT_FALSE(std::all_of(feature_vector.begin(), feature_vector.end(),
[](float x) { return x == kInitialFeatureVal; }));
}
// Feeds a constant input signal and checks that:
// - the cepstral coefficients average does not change;
// - the derivatives are zero;
// - the cepstral variability score does not change.
TEST(RnnVadTest, CepstralFeaturesConstantAverageZeroDerivative) {
// Initialize.
SpectralFeaturesExtractor sfe;
std::array<float, kFrameSize20ms24kHz> samples;
rtc::ArrayView<float, kFrameSize20ms24kHz> samples_view(samples);
WriteTestData(samples);
// Fill the spectral features with test data.
std::array<float, kTestFeatureVectorSize> feature_vector;
for (int i = 0; i < kCepstralCoeffsHistorySize; ++i) {
sfe.CheckSilenceComputeFeatures(
samples_view, samples_view, GetHigherBandsSpectrum(&feature_vector),
GetAverage(&feature_vector), GetFirstDerivative(&feature_vector),
GetSecondDerivative(&feature_vector),
GetCepstralCrossCorrelation(&feature_vector),
GetCepstralVariability(&feature_vector));
}
// Feed the test data one last time but using a different output vector.
std::array<float, kTestFeatureVectorSize> feature_vector_last;
sfe.CheckSilenceComputeFeatures(
samples_view, samples_view, GetHigherBandsSpectrum(&feature_vector_last),
GetAverage(&feature_vector_last),
GetFirstDerivative(&feature_vector_last),
GetSecondDerivative(&feature_vector_last),
GetCepstralCrossCorrelation(&feature_vector_last),
GetCepstralVariability(&feature_vector_last));
// Average is unchanged.
ExpectEqualFloatArray({feature_vector.data(), kNumLowerBands},
{feature_vector_last.data(), kNumLowerBands});
// First and second derivatives are zero.
constexpr std::array<float, kNumLowerBands> zeros{};
ExpectEqualFloatArray(
{feature_vector_last.data() + kNumBands, kNumLowerBands}, zeros);
ExpectEqualFloatArray(
{feature_vector_last.data() + kNumBands + kNumLowerBands, kNumLowerBands},
zeros);
// Variability is unchanged.
EXPECT_FLOAT_EQ(feature_vector[kNumBands + 3 * kNumLowerBands],
feature_vector_last[kNumBands + 3 * kNumLowerBands]);
}
} // namespace
} // namespace rnn_vad
} // namespace webrtc