Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/main_filter_update_gain_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/main_filter_update_gain.h"
+
+#include <algorithm>
+#include <numeric>
+#include <string>
+
+#include "webrtc/base/random.h"
+#include "webrtc/modules/audio_processing/aec3/adaptive_fir_filter.h"
+#include "webrtc/modules/audio_processing/aec3/aec_state.h"
+#include "webrtc/modules/audio_processing/aec3/fft_buffer.h"
+#include "webrtc/modules/audio_processing/aec3/render_signal_analyzer.h"
+#include "webrtc/modules/audio_processing/aec3/shadow_filter_update_gain.h"
+#include "webrtc/modules/audio_processing/aec3/subtractor_output.h"
+#include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
+#include "webrtc/modules/audio_processing/test/echo_canceller_test_tools.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+// Method for performing the simulations needed to test the main filter update
+// gain functionality.
+void RunFilterUpdateTest(int num_blocks_to_process,
+                         size_t delay_samples,
+                         const std::vector<int>& blocks_with_echo_path_changes,
+                         const std::vector<int>& blocks_with_saturation,
+                         bool use_silent_render_in_second_half,
+                         std::array<float, kBlockSize>* e_last_block,
+                         std::array<float, kBlockSize>* y_last_block,
+                         FftData* G_last_block) {
+  ApmDataDumper data_dumper(42);
+  AdaptiveFirFilter main_filter(9, true, DetectOptimization(), &data_dumper);
+  AdaptiveFirFilter shadow_filter(9, true, DetectOptimization(), &data_dumper);
+  Aec3Fft fft;
+  FftBuffer X_buffer(Aec3Optimization::kNone, main_filter.SizePartitions(),
+                     std::vector<size_t>(1, main_filter.SizePartitions()));
+  std::array<float, kBlockSize> x_old;
+  x_old.fill(0.f);
+  ShadowFilterUpdateGain shadow_gain;
+  MainFilterUpdateGain main_gain;
+  Random random_generator(42U);
+  std::vector<float> x(kBlockSize, 0.f);
+  std::vector<float> y(kBlockSize, 0.f);
+  AecState aec_state;
+  RenderSignalAnalyzer render_signal_analyzer;
+  FftData X;
+  std::array<float, kFftLength> s;
+  FftData S;
+  FftData G;
+  SubtractorOutput output;
+  output.Reset();
+  FftData& E_main = output.E_main;
+  FftData& E_shadow = output.E_shadow;
+  std::array<float, kFftLengthBy2Plus1> Y2;
+  std::array<float, kFftLengthBy2Plus1>& E2_main = output.E2_main;
+  std::array<float, kFftLengthBy2Plus1>& E2_shadow = output.E2_shadow;
+  std::array<float, kBlockSize>& e_main = output.e_main;
+  std::array<float, kBlockSize>& e_shadow = output.e_shadow;
+  Y2.fill(0.f);
+
+  constexpr float kScale = 1.0f / kFftLengthBy2;
+
+  DelayBuffer<float> delay_buffer(delay_samples);
+  for (int k = 0; k < num_blocks_to_process; ++k) {
+    // Handle echo path changes.
+    if (std::find(blocks_with_echo_path_changes.begin(),
+                  blocks_with_echo_path_changes.end(),
+                  k) != blocks_with_echo_path_changes.end()) {
+      main_filter.HandleEchoPathChange();
+    }
+
+    // Handle saturation.
+    const bool saturation =
+        std::find(blocks_with_saturation.begin(), blocks_with_saturation.end(),
+                  k) != blocks_with_saturation.end();
+
+    // Create the render signal.
+    if (use_silent_render_in_second_half && k > num_blocks_to_process / 2) {
+      std::fill(x.begin(), x.end(), 0.f);
+    } else {
+      RandomizeSampleVector(&random_generator, x);
+    }
+    delay_buffer.Delay(x, y);
+    fft.PaddedFft(x, x_old, &X);
+    X_buffer.Insert(X);
+    render_signal_analyzer.Update(X_buffer, aec_state.FilterDelay());
+
+    // Apply the main filter.
+    main_filter.Filter(X_buffer, &S);
+    fft.Ifft(S, &s);
+    std::transform(y.begin(), y.end(), s.begin() + kFftLengthBy2,
+                   e_main.begin(),
+                   [&](float a, float b) { return a - b * kScale; });
+    std::for_each(e_main.begin(), e_main.end(), [](float& a) {
+      a = std::max(std::min(a, 32767.0f), -32768.0f);
+    });
+    fft.ZeroPaddedFft(e_main, &E_main);
+
+    // Apply the shadow filter.
+    shadow_filter.Filter(X_buffer, &S);
+    fft.Ifft(S, &s);
+    std::transform(y.begin(), y.end(), s.begin() + kFftLengthBy2,
+                   e_shadow.begin(),
+                   [&](float a, float b) { return a - b * kScale; });
+    std::for_each(e_shadow.begin(), e_shadow.end(), [](float& a) {
+      a = std::max(std::min(a, 32767.0f), -32768.0f);
+    });
+    fft.ZeroPaddedFft(e_shadow, &E_shadow);
+
+    // Compute spectra for future use.
+    E_main.Spectrum(Aec3Optimization::kNone, &output.E2_main);
+    E_shadow.Spectrum(Aec3Optimization::kNone, &output.E2_shadow);
+
+    // Adapt the shadow filter.
+    shadow_gain.Compute(X_buffer, render_signal_analyzer, E_shadow,
+                        shadow_filter.SizePartitions(), saturation, &G);
+    shadow_filter.Adapt(X_buffer, G);
+
+    // Adapt the main filter
+    main_gain.Compute(X_buffer, render_signal_analyzer, output, main_filter,
+                      saturation, &G);
+    main_filter.Adapt(X_buffer, G);
+
+    // Update the delay.
+    aec_state.Update(main_filter.FilterFrequencyResponse(),
+                     rtc::Optional<size_t>(), X_buffer, E2_main, E2_shadow, Y2,
+                     x, EchoPathVariability(false, false), false);
+  }
+
+  std::copy(e_main.begin(), e_main.end(), e_last_block->begin());
+  std::copy(y.begin(), y.end(), y_last_block->begin());
+  std::copy(G.re.begin(), G.re.end(), G_last_block->re.begin());
+  std::copy(G.im.begin(), G.im.end(), G_last_block->im.begin());
+}
+
+std::string ProduceDebugText(size_t delay) {
+  std::ostringstream ss;
+  ss << "Delay: " << delay;
+  return ss.str();
+}
+
+}  // namespace
+
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+
+// Verifies that the check for non-null output gain parameter works.
+TEST(MainFilterUpdateGain, NullDataOutputGain) {
+  ApmDataDumper data_dumper(42);
+  AdaptiveFirFilter filter(9, true, DetectOptimization(), &data_dumper);
+  FftBuffer X_buffer(Aec3Optimization::kNone, filter.SizePartitions(),
+                     std::vector<size_t>(1, filter.SizePartitions()));
+  RenderSignalAnalyzer analyzer;
+  SubtractorOutput output;
+  MainFilterUpdateGain gain;
+  EXPECT_DEATH(gain.Compute(X_buffer, analyzer, output, filter, false, nullptr),
+               "");
+}
+
+#endif
+
+// Verifies that the gain formed causes the filter using it to converge.
+TEST(MainFilterUpdateGain, GainCausesFilterToConverge) {
+  std::vector<int> blocks_with_echo_path_changes;
+  std::vector<int> blocks_with_saturation;
+  for (size_t delay_samples : {0, 64, 150, 200, 301}) {
+    SCOPED_TRACE(ProduceDebugText(delay_samples));
+
+    std::array<float, kBlockSize> e;
+    std::array<float, kBlockSize> y;
+    FftData G;
+
+    RunFilterUpdateTest(500, delay_samples, blocks_with_echo_path_changes,
+                        blocks_with_saturation, false, &e, &y, &G);
+
+    // Verify that the main filter is able to perform well.
+    EXPECT_LT(1000 * std::inner_product(e.begin(), e.end(), e.begin(), 0.f),
+              std::inner_product(y.begin(), y.end(), y.begin(), 0.f));
+  }
+}
+
+// Verifies that the magnitude of the gain on average decreases for a
+// persistently exciting signal.
+TEST(MainFilterUpdateGain, DecreasingGain) {
+  std::vector<int> blocks_with_echo_path_changes;
+  std::vector<int> blocks_with_saturation;
+
+  std::array<float, kBlockSize> e;
+  std::array<float, kBlockSize> y;
+  FftData G_a;
+  FftData G_b;
+  FftData G_c;
+  std::array<float, kFftLengthBy2Plus1> G_a_power;
+  std::array<float, kFftLengthBy2Plus1> G_b_power;
+  std::array<float, kFftLengthBy2Plus1> G_c_power;
+
+  RunFilterUpdateTest(100, 65, blocks_with_echo_path_changes,
+                      blocks_with_saturation, false, &e, &y, &G_a);
+  RunFilterUpdateTest(200, 65, blocks_with_echo_path_changes,
+                      blocks_with_saturation, false, &e, &y, &G_b);
+  RunFilterUpdateTest(300, 65, blocks_with_echo_path_changes,
+                      blocks_with_saturation, false, &e, &y, &G_c);
+
+  G_a.Spectrum(Aec3Optimization::kNone, &G_a_power);
+  G_b.Spectrum(Aec3Optimization::kNone, &G_b_power);
+  G_c.Spectrum(Aec3Optimization::kNone, &G_c_power);
+
+  EXPECT_GT(std::accumulate(G_a_power.begin(), G_a_power.end(), 0.),
+            std::accumulate(G_b_power.begin(), G_b_power.end(), 0.));
+
+  EXPECT_GT(std::accumulate(G_b_power.begin(), G_b_power.end(), 0.),
+            std::accumulate(G_c_power.begin(), G_c_power.end(), 0.));
+}
+
+// Verifies that the gain is zero when there is saturation and that the internal
+// error estimates cause the gain to increase after a period of saturation.
+TEST(MainFilterUpdateGain, SaturationBehavior) {
+  std::vector<int> blocks_with_echo_path_changes;
+  std::vector<int> blocks_with_saturation;
+  for (int k = 99; k < 200; ++k) {
+    blocks_with_saturation.push_back(k);
+  }
+
+  std::array<float, kBlockSize> e;
+  std::array<float, kBlockSize> y;
+  FftData G_a;
+  FftData G_b;
+  FftData G_a_ref;
+  G_a_ref.re.fill(0.f);
+  G_a_ref.im.fill(0.f);
+
+  std::array<float, kFftLengthBy2Plus1> G_a_power;
+  std::array<float, kFftLengthBy2Plus1> G_b_power;
+
+  RunFilterUpdateTest(100, 65, blocks_with_echo_path_changes,
+                      blocks_with_saturation, false, &e, &y, &G_a);
+
+  EXPECT_EQ(G_a_ref.re, G_a.re);
+  EXPECT_EQ(G_a_ref.im, G_a.im);
+
+  RunFilterUpdateTest(99, 65, blocks_with_echo_path_changes,
+                      blocks_with_saturation, false, &e, &y, &G_a);
+  RunFilterUpdateTest(201, 65, blocks_with_echo_path_changes,
+                      blocks_with_saturation, false, &e, &y, &G_b);
+
+  G_a.Spectrum(Aec3Optimization::kNone, &G_a_power);
+  G_b.Spectrum(Aec3Optimization::kNone, &G_b_power);
+
+  EXPECT_LT(std::accumulate(G_a_power.begin(), G_a_power.end(), 0.),
+            std::accumulate(G_b_power.begin(), G_b_power.end(), 0.));
+}
+
+// Verifies that the gain increases after an echo path change.
+TEST(MainFilterUpdateGain, EchoPathChangeBehavior) {
+  std::vector<int> blocks_with_echo_path_changes;
+  std::vector<int> blocks_with_saturation;
+  blocks_with_echo_path_changes.push_back(99);
+
+  std::array<float, kBlockSize> e;
+  std::array<float, kBlockSize> y;
+  FftData G_a;
+  FftData G_b;
+  std::array<float, kFftLengthBy2Plus1> G_a_power;
+  std::array<float, kFftLengthBy2Plus1> G_b_power;
+
+  RunFilterUpdateTest(99, 65, blocks_with_echo_path_changes,
+                      blocks_with_saturation, false, &e, &y, &G_a);
+  RunFilterUpdateTest(100, 65, blocks_with_echo_path_changes,
+                      blocks_with_saturation, false, &e, &y, &G_b);
+
+  G_a.Spectrum(Aec3Optimization::kNone, &G_a_power);
+  G_b.Spectrum(Aec3Optimization::kNone, &G_b_power);
+
+  EXPECT_LT(std::accumulate(G_a_power.begin(), G_a_power.end(), 0.),
+            std::accumulate(G_b_power.begin(), G_b_power.end(), 0.));
+}
+
+}  // namespace webrtc