1 files changed, 160 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_unittest.cc
new file mode 100644
index 0000000000..324d694957
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/spectral_features_unittest.cc
@@ -0,0 +1,160 @@
+/*
+ *  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