Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/render_signal_analyzer_unittest.cc

+/*
+ *  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.
+ */
+
+#include "webrtc/modules/audio_processing/aec3/render_signal_analyzer.h"
+
+#include <math.h>
+#include <array>
+#include <vector>
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/base/random.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_common.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_fft.h"
+#include "webrtc/modules/audio_processing/aec3/fft_buffer.h"
+#include "webrtc/modules/audio_processing/aec3/fft_data.h"
+#include "webrtc/modules/audio_processing/test/echo_canceller_test_tools.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+constexpr float kPi = 3.141592f;
+
+void ProduceSinusoid(int sample_rate_hz,
+                     float sinusoidal_frequency_hz,
+                     size_t* sample_counter,
+                     rtc::ArrayView<float> x) {
+  // Produce a sinusoid of the specified frequency.
+  for (size_t k = *sample_counter, j = 0; k < (*sample_counter + kBlockSize);
+       ++k, ++j) {
+    x[j] =
+        32767.f * sin(2.f * kPi * sinusoidal_frequency_hz * k / sample_rate_hz);
+  }
+  *sample_counter = *sample_counter + kBlockSize;
+}
+
+}  // namespace
+
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+// Verifies that the check for non-null output parameter works.
+TEST(RenderSignalAnalyzer, NullMaskOutput) {
+  RenderSignalAnalyzer analyzer;
+  EXPECT_DEATH(analyzer.MaskRegionsAroundNarrowBands(nullptr), "");
+}
+
+#endif
+
+// Verify that no narrow bands are detected in a Gaussian noise signal.
+TEST(RenderSignalAnalyzer, NoFalseDetectionOfNarrowBands) {
+  RenderSignalAnalyzer analyzer;
+  Random random_generator(42U);
+  std::vector<float> x(kBlockSize, 0.f);
+  std::array<float, kBlockSize> x_old;
+  FftData X;
+  Aec3Fft fft;
+  FftBuffer X_buffer(Aec3Optimization::kNone, 1, std::vector<size_t>(1, 1));
+  std::array<float, kFftLengthBy2Plus1> mask;
+  x_old.fill(0.f);
+
+  for (size_t k = 0; k < 100; ++k) {
+    RandomizeSampleVector(&random_generator, x);
+    fft.PaddedFft(x, x_old, &X);
+    X_buffer.Insert(X);
+    analyzer.Update(X_buffer, rtc::Optional<size_t>(0));
+  }
+
+  mask.fill(1.f);
+  analyzer.MaskRegionsAroundNarrowBands(&mask);
+  EXPECT_TRUE(
+      std::all_of(mask.begin(), mask.end(), [](float a) { return a == 1.f; }));
+  EXPECT_FALSE(analyzer.PoorSignalExcitation());
+}
+
+// Verify that a sinusiod signal is detected as narrow bands.
+TEST(RenderSignalAnalyzer, NarrowBandDetection) {
+  RenderSignalAnalyzer analyzer;
+  Random random_generator(42U);
+  std::vector<float> x(kBlockSize, 0.f);
+  std::array<float, kBlockSize> x_old;
+  FftData X;
+  Aec3Fft fft;
+  FftBuffer X_buffer(Aec3Optimization::kNone, 1, std::vector<size_t>(1, 1));
+  std::array<float, kFftLengthBy2Plus1> mask;
+  x_old.fill(0.f);
+  constexpr int kSinusFrequencyBin = 32;
+
+  auto generate_sinusoid_test = [&](bool known_delay) {
+    size_t sample_counter = 0;
+    for (size_t k = 0; k < 100; ++k) {
+      ProduceSinusoid(16000, 16000 / 2 * kSinusFrequencyBin / kFftLengthBy2,
+                      &sample_counter, x);
+      fft.PaddedFft(x, x_old, &X);
+      X_buffer.Insert(X);
+      analyzer.Update(
+          X_buffer,
+          known_delay ? rtc::Optional<size_t>(0) : rtc::Optional<size_t>());
+    }
+  };
+
+  generate_sinusoid_test(true);
+  mask.fill(1.f);
+  analyzer.MaskRegionsAroundNarrowBands(&mask);
+  for (int k = 0; k < static_cast<int>(mask.size()); ++k) {
+    EXPECT_EQ(abs(k - kSinusFrequencyBin) <= 2 ? 0.f : 1.f, mask[k]);
+  }
+  EXPECT_TRUE(analyzer.PoorSignalExcitation());
+
+  // Verify that no bands are detected as narrow when the delay is unknown.
+  generate_sinusoid_test(false);
+  mask.fill(1.f);
+  analyzer.MaskRegionsAroundNarrowBands(&mask);
+  std::for_each(mask.begin(), mask.end(), [](float a) { EXPECT_EQ(1.f, a); });
+  EXPECT_FALSE(analyzer.PoorSignalExcitation());
+}
+
+}  // namespace webrtc