1 files changed, 612 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_processing/aec3/matched_filter_unittest.cc b/third_party/libwebrtc/modules/audio_processing/aec3/matched_filter_unittest.cc
new file mode 100644
index 0000000000..3f26cc146e
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/aec3/matched_filter_unittest.cc
@@ -0,0 +1,612 @@
+/*
+ *  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 "modules/audio_processing/aec3/matched_filter.h"
+
+// Defines WEBRTC_ARCH_X86_FAMILY, used below.
+#include "rtc_base/system/arch.h"
+
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+#include <emmintrin.h>
+#endif
+#include <algorithm>
+#include <string>
+
+#include "modules/audio_processing/aec3/aec3_common.h"
+#include "modules/audio_processing/aec3/decimator.h"
+#include "modules/audio_processing/aec3/render_delay_buffer.h"
+#include "modules/audio_processing/logging/apm_data_dumper.h"
+#include "modules/audio_processing/test/echo_canceller_test_tools.h"
+#include "rtc_base/random.h"
+#include "rtc_base/strings/string_builder.h"
+#include "system_wrappers/include/cpu_features_wrapper.h"
+#include "test/field_trial.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace aec3 {
+namespace {
+
+std::string ProduceDebugText(size_t delay, size_t down_sampling_factor) {
+  rtc::StringBuilder ss;
+  ss << "Delay: " << delay;
+  ss << ", Down sampling factor: " << down_sampling_factor;
+  return ss.Release();
+}
+
+constexpr size_t kNumMatchedFilters = 10;
+constexpr size_t kDownSamplingFactors[] = {2, 4, 8};
+constexpr size_t kWindowSizeSubBlocks = 32;
+constexpr size_t kAlignmentShiftSubBlocks = kWindowSizeSubBlocks * 3 / 4;
+
+}  // namespace
+
+class MatchedFilterTest : public ::testing::TestWithParam<bool> {};
+
+#if defined(WEBRTC_HAS_NEON)
+// Verifies that the optimized methods for NEON are similar to their reference
+// counterparts.
+TEST_P(MatchedFilterTest, TestNeonOptimizations) {
+  Random random_generator(42U);
+  constexpr float kSmoothing = 0.7f;
+  const bool kComputeAccumulatederror = GetParam();
+  for (auto down_sampling_factor : kDownSamplingFactors) {
+    const size_t sub_block_size = kBlockSize / down_sampling_factor;
+
+    std::vector<float> x(2000);
+    RandomizeSampleVector(&random_generator, x);
+    std::vector<float> y(sub_block_size);
+    std::vector<float> h_NEON(512);
+    std::vector<float> h(512);
+    std::vector<float> accumulated_error(512);
+    std::vector<float> accumulated_error_NEON(512);
+    std::vector<float> scratch_memory(512);
+
+    int x_index = 0;
+    for (int k = 0; k < 1000; ++k) {
+      RandomizeSampleVector(&random_generator, y);
+
+      bool filters_updated = false;
+      float error_sum = 0.f;
+      bool filters_updated_NEON = false;
+      float error_sum_NEON = 0.f;
+
+      MatchedFilterCore_NEON(x_index, h.size() * 150.f * 150.f, kSmoothing, x,
+                             y, h_NEON, &filters_updated_NEON, &error_sum_NEON,
+                             kComputeAccumulatederror, accumulated_error_NEON,
+                             scratch_memory);
+
+      MatchedFilterCore(x_index, h.size() * 150.f * 150.f, kSmoothing, x, y, h,
+                        &filters_updated, &error_sum, kComputeAccumulatederror,
+                        accumulated_error);
+
+      EXPECT_EQ(filters_updated, filters_updated_NEON);
+      EXPECT_NEAR(error_sum, error_sum_NEON, error_sum / 100000.f);
+
+      for (size_t j = 0; j < h.size(); ++j) {
+        EXPECT_NEAR(h[j], h_NEON[j], 0.00001f);
+      }
+
+      if (kComputeAccumulatederror) {
+        for (size_t j = 0; j < accumulated_error.size(); ++j) {
+          float difference =
+              std::abs(accumulated_error[j] - accumulated_error_NEON[j]);
+          float relative_difference = accumulated_error[j] > 0
+                                          ? difference / accumulated_error[j]
+                                          : difference;
+          EXPECT_NEAR(relative_difference, 0.0f, 0.02f);
+        }
+      }
+
+      x_index = (x_index + sub_block_size) % x.size();
+    }
+  }
+}
+#endif
+
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+// Verifies that the optimized methods for SSE2 are bitexact to their reference
+// counterparts.
+TEST_P(MatchedFilterTest, TestSse2Optimizations) {
+  const bool kComputeAccumulatederror = GetParam();
+  bool use_sse2 = (GetCPUInfo(kSSE2) != 0);
+  if (use_sse2) {
+    Random random_generator(42U);
+    constexpr float kSmoothing = 0.7f;
+    for (auto down_sampling_factor : kDownSamplingFactors) {
+      const size_t sub_block_size = kBlockSize / down_sampling_factor;
+      std::vector<float> x(2000);
+      RandomizeSampleVector(&random_generator, x);
+      std::vector<float> y(sub_block_size);
+      std::vector<float> h_SSE2(512);
+      std::vector<float> h(512);
+      std::vector<float> accumulated_error(512 / 4);
+      std::vector<float> accumulated_error_SSE2(512 / 4);
+      std::vector<float> scratch_memory(512);
+      int x_index = 0;
+      for (int k = 0; k < 1000; ++k) {
+        RandomizeSampleVector(&random_generator, y);
+
+        bool filters_updated = false;
+        float error_sum = 0.f;
+        bool filters_updated_SSE2 = false;
+        float error_sum_SSE2 = 0.f;
+
+        MatchedFilterCore_SSE2(x_index, h.size() * 150.f * 150.f, kSmoothing, x,
+                               y, h_SSE2, &filters_updated_SSE2,
+                               &error_sum_SSE2, kComputeAccumulatederror,
+                               accumulated_error_SSE2, scratch_memory);
+
+        MatchedFilterCore(x_index, h.size() * 150.f * 150.f, kSmoothing, x, y,
+                          h, &filters_updated, &error_sum,
+                          kComputeAccumulatederror, accumulated_error);
+
+        EXPECT_EQ(filters_updated, filters_updated_SSE2);
+        EXPECT_NEAR(error_sum, error_sum_SSE2, error_sum / 100000.f);
+
+        for (size_t j = 0; j < h.size(); ++j) {
+          EXPECT_NEAR(h[j], h_SSE2[j], 0.00001f);
+        }
+
+        for (size_t j = 0; j < accumulated_error.size(); ++j) {
+          float difference =
+              std::abs(accumulated_error[j] - accumulated_error_SSE2[j]);
+          float relative_difference = accumulated_error[j] > 0
+                                          ? difference / accumulated_error[j]
+                                          : difference;
+          EXPECT_NEAR(relative_difference, 0.0f, 0.00001f);
+        }
+
+        x_index = (x_index + sub_block_size) % x.size();
+      }
+    }
+  }
+}
+
+TEST_P(MatchedFilterTest, TestAvx2Optimizations) {
+  bool use_avx2 = (GetCPUInfo(kAVX2) != 0);
+  const bool kComputeAccumulatederror = GetParam();
+  if (use_avx2) {
+    Random random_generator(42U);
+    constexpr float kSmoothing = 0.7f;
+    for (auto down_sampling_factor : kDownSamplingFactors) {
+      const size_t sub_block_size = kBlockSize / down_sampling_factor;
+      std::vector<float> x(2000);
+      RandomizeSampleVector(&random_generator, x);
+      std::vector<float> y(sub_block_size);
+      std::vector<float> h_AVX2(512);
+      std::vector<float> h(512);
+      std::vector<float> accumulated_error(512 / 4);
+      std::vector<float> accumulated_error_AVX2(512 / 4);
+      std::vector<float> scratch_memory(512);
+      int x_index = 0;
+      for (int k = 0; k < 1000; ++k) {
+        RandomizeSampleVector(&random_generator, y);
+        bool filters_updated = false;
+        float error_sum = 0.f;
+        bool filters_updated_AVX2 = false;
+        float error_sum_AVX2 = 0.f;
+        MatchedFilterCore_AVX2(x_index, h.size() * 150.f * 150.f, kSmoothing, x,
+                               y, h_AVX2, &filters_updated_AVX2,
+                               &error_sum_AVX2, kComputeAccumulatederror,
+                               accumulated_error_AVX2, scratch_memory);
+        MatchedFilterCore(x_index, h.size() * 150.f * 150.f, kSmoothing, x, y,
+                          h, &filters_updated, &error_sum,
+                          kComputeAccumulatederror, accumulated_error);
+        EXPECT_EQ(filters_updated, filters_updated_AVX2);
+        EXPECT_NEAR(error_sum, error_sum_AVX2, error_sum / 100000.f);
+        for (size_t j = 0; j < h.size(); ++j) {
+          EXPECT_NEAR(h[j], h_AVX2[j], 0.00001f);
+        }
+        for (size_t j = 0; j < accumulated_error.size(); j += 4) {
+          float difference =
+              std::abs(accumulated_error[j] - accumulated_error_AVX2[j]);
+          float relative_difference = accumulated_error[j] > 0
+                                          ? difference / accumulated_error[j]
+                                          : difference;
+          EXPECT_NEAR(relative_difference, 0.0f, 0.00001f);
+        }
+        x_index = (x_index + sub_block_size) % x.size();
+      }
+    }
+  }
+}
+
+#endif
+
+// Verifies that the (optimized) function MaxSquarePeakIndex() produces output
+// equal to the corresponding std-functions.
+TEST(MatchedFilter, MaxSquarePeakIndex) {
+  Random random_generator(42U);
+  constexpr int kMaxLength = 128;
+  constexpr int kNumIterationsPerLength = 256;
+  for (int length = 1; length < kMaxLength; ++length) {
+    std::vector<float> y(length);
+    for (int i = 0; i < kNumIterationsPerLength; ++i) {
+      RandomizeSampleVector(&random_generator, y);
+
+      size_t lag_from_function = MaxSquarePeakIndex(y);
+      size_t lag_from_std = std::distance(
+          y.begin(),
+          std::max_element(y.begin(), y.end(), [](float a, float b) -> bool {
+            return a * a < b * b;
+          }));
+      EXPECT_EQ(lag_from_function, lag_from_std);
+    }
+  }
+}
+
+// Verifies that the matched filter produces proper lag estimates for
+// artificially delayed signals.
+TEST_P(MatchedFilterTest, LagEstimation) {
+  const bool kDetectPreEcho = GetParam();
+  Random random_generator(42U);
+  constexpr size_t kNumChannels = 1;
+  constexpr int kSampleRateHz = 48000;
+  constexpr size_t kNumBands = NumBandsForRate(kSampleRateHz);
+
+  for (auto down_sampling_factor : kDownSamplingFactors) {
+    const size_t sub_block_size = kBlockSize / down_sampling_factor;
+
+    Block render(kNumBands, kNumChannels);
+    std::vector<std::vector<float>> capture(
+        1, std::vector<float>(kBlockSize, 0.f));
+    ApmDataDumper data_dumper(0);
+    for (size_t delay_samples : {5, 64, 150, 200, 800, 1000}) {
+      SCOPED_TRACE(ProduceDebugText(delay_samples, down_sampling_factor));
+      EchoCanceller3Config config;
+      config.delay.down_sampling_factor = down_sampling_factor;
+      config.delay.num_filters = kNumMatchedFilters;
+      Decimator capture_decimator(down_sampling_factor);
+      DelayBuffer<float> signal_delay_buffer(down_sampling_factor *
+                                             delay_samples);
+      MatchedFilter filter(
+          &data_dumper, DetectOptimization(), sub_block_size,
+          kWindowSizeSubBlocks, kNumMatchedFilters, kAlignmentShiftSubBlocks,
+          150, config.delay.delay_estimate_smoothing,
+          config.delay.delay_estimate_smoothing_delay_found,
+          config.delay.delay_candidate_detection_threshold, kDetectPreEcho);
+
+      std::unique_ptr<RenderDelayBuffer> render_delay_buffer(
+          RenderDelayBuffer::Create(config, kSampleRateHz, kNumChannels));
+
+      // Analyze the correlation between render and capture.
+      for (size_t k = 0; k < (600 + delay_samples / sub_block_size); ++k) {
+        for (size_t band = 0; band < kNumBands; ++band) {
+          for (size_t channel = 0; channel < kNumChannels; ++channel) {
+            RandomizeSampleVector(&random_generator,
+                                  render.View(band, channel));
+          }
+        }
+        signal_delay_buffer.Delay(render.View(/*band=*/0, /*channel=*/0),
+                                  capture[0]);
+        render_delay_buffer->Insert(render);
+
+        if (k == 0) {
+          render_delay_buffer->Reset();
+        }
+
+        render_delay_buffer->PrepareCaptureProcessing();
+        std::array<float, kBlockSize> downsampled_capture_data;
+        rtc::ArrayView<float> downsampled_capture(
+            downsampled_capture_data.data(), sub_block_size);
+        capture_decimator.Decimate(capture[0], downsampled_capture);
+        filter.Update(render_delay_buffer->GetDownsampledRenderBuffer(),
+                      downsampled_capture, /*use_slow_smoothing=*/false);
+      }
+
+      // Obtain the lag estimates.
+      auto lag_estimate = filter.GetBestLagEstimate();
+      EXPECT_TRUE(lag_estimate.has_value());
+
+      // Verify that the expected most accurate lag estimate is correct.
+      if (lag_estimate.has_value()) {
+        EXPECT_EQ(delay_samples, lag_estimate->lag);
+        EXPECT_EQ(delay_samples, lag_estimate->pre_echo_lag);
+      }
+    }
+  }
+}
+
+// Test the pre echo estimation.
+TEST_P(MatchedFilterTest, PreEchoEstimation) {
+  const bool kDetectPreEcho = GetParam();
+  Random random_generator(42U);
+  constexpr size_t kNumChannels = 1;
+  constexpr int kSampleRateHz = 48000;
+  constexpr size_t kNumBands = NumBandsForRate(kSampleRateHz);
+
+  for (auto down_sampling_factor : kDownSamplingFactors) {
+    const size_t sub_block_size = kBlockSize / down_sampling_factor;
+
+    Block render(kNumBands, kNumChannels);
+    std::vector<std::vector<float>> capture(
+        1, std::vector<float>(kBlockSize, 0.f));
+    std::vector<float> capture_with_pre_echo(kBlockSize, 0.f);
+    ApmDataDumper data_dumper(0);
+    // data_dumper.SetActivated(true);
+    size_t pre_echo_delay_samples = 20e-3 * 16000 / down_sampling_factor;
+    size_t echo_delay_samples = 50e-3 * 16000 / down_sampling_factor;
+    EchoCanceller3Config config;
+    config.delay.down_sampling_factor = down_sampling_factor;
+    config.delay.num_filters = kNumMatchedFilters;
+    Decimator capture_decimator(down_sampling_factor);
+    DelayBuffer<float> signal_echo_delay_buffer(down_sampling_factor *
+                                                echo_delay_samples);
+    DelayBuffer<float> signal_pre_echo_delay_buffer(down_sampling_factor *
+                                                    pre_echo_delay_samples);
+    MatchedFilter filter(
+        &data_dumper, DetectOptimization(), sub_block_size,
+        kWindowSizeSubBlocks, kNumMatchedFilters, kAlignmentShiftSubBlocks, 150,
+        config.delay.delay_estimate_smoothing,
+        config.delay.delay_estimate_smoothing_delay_found,
+        config.delay.delay_candidate_detection_threshold, kDetectPreEcho);
+    std::unique_ptr<RenderDelayBuffer> render_delay_buffer(
+        RenderDelayBuffer::Create(config, kSampleRateHz, kNumChannels));
+    // Analyze the correlation between render and capture.
+    for (size_t k = 0; k < (600 + echo_delay_samples / sub_block_size); ++k) {
+      for (size_t band = 0; band < kNumBands; ++band) {
+        for (size_t channel = 0; channel < kNumChannels; ++channel) {
+          RandomizeSampleVector(&random_generator, render.View(band, channel));
+        }
+      }
+      signal_echo_delay_buffer.Delay(render.View(0, 0), capture[0]);
+      signal_pre_echo_delay_buffer.Delay(render.View(0, 0),
+                                         capture_with_pre_echo);
+      for (size_t k = 0; k < capture[0].size(); ++k) {
+        constexpr float gain_pre_echo = 0.8f;
+        capture[0][k] += gain_pre_echo * capture_with_pre_echo[k];
+      }
+      render_delay_buffer->Insert(render);
+      if (k == 0) {
+        render_delay_buffer->Reset();
+      }
+      render_delay_buffer->PrepareCaptureProcessing();
+      std::array<float, kBlockSize> downsampled_capture_data;
+      rtc::ArrayView<float> downsampled_capture(downsampled_capture_data.data(),
+                                                sub_block_size);
+      capture_decimator.Decimate(capture[0], downsampled_capture);
+      filter.Update(render_delay_buffer->GetDownsampledRenderBuffer(),
+                    downsampled_capture, /*use_slow_smoothing=*/false);
+    }
+    // Obtain the lag estimates.
+    auto lag_estimate = filter.GetBestLagEstimate();
+    EXPECT_TRUE(lag_estimate.has_value());
+    // Verify that the expected most accurate lag estimate is correct.
+    if (lag_estimate.has_value()) {
+      EXPECT_EQ(echo_delay_samples, lag_estimate->lag);
+      if (kDetectPreEcho) {
+        // The pre echo delay is estimated in a subsampled domain and a larger
+        // error is allowed.
+        EXPECT_NEAR(pre_echo_delay_samples, lag_estimate->pre_echo_lag, 4);
+      } else {
+        // The pre echo delay fallback to the highest mached filter peak when
+        // its detection is disabled.
+        EXPECT_EQ(echo_delay_samples, lag_estimate->pre_echo_lag);
+      }
+    }
+  }
+}
+
+// Verifies that the matched filter does not produce reliable and accurate
+// estimates for uncorrelated render and capture signals.
+TEST_P(MatchedFilterTest, LagNotReliableForUncorrelatedRenderAndCapture) {
+  const bool kDetectPreEcho = GetParam();
+  constexpr size_t kNumChannels = 1;
+  constexpr int kSampleRateHz = 48000;
+  constexpr size_t kNumBands = NumBandsForRate(kSampleRateHz);
+  Random random_generator(42U);
+  for (auto down_sampling_factor : kDownSamplingFactors) {
+    EchoCanceller3Config config;
+    config.delay.down_sampling_factor = down_sampling_factor;
+    config.delay.num_filters = kNumMatchedFilters;
+    const size_t sub_block_size = kBlockSize / down_sampling_factor;
+
+    Block render(kNumBands, kNumChannels);
+    std::array<float, kBlockSize> capture_data;
+    rtc::ArrayView<float> capture(capture_data.data(), sub_block_size);
+    std::fill(capture.begin(), capture.end(), 0.f);
+    ApmDataDumper data_dumper(0);
+    std::unique_ptr<RenderDelayBuffer> render_delay_buffer(
+        RenderDelayBuffer::Create(config, kSampleRateHz, kNumChannels));
+    MatchedFilter filter(
+        &data_dumper, DetectOptimization(), sub_block_size,
+        kWindowSizeSubBlocks, kNumMatchedFilters, kAlignmentShiftSubBlocks, 150,
+        config.delay.delay_estimate_smoothing,
+        config.delay.delay_estimate_smoothing_delay_found,
+        config.delay.delay_candidate_detection_threshold, kDetectPreEcho);
+
+    // Analyze the correlation between render and capture.
+    for (size_t k = 0; k < 100; ++k) {
+      RandomizeSampleVector(&random_generator,
+                            render.View(/*band=*/0, /*channel=*/0));
+      RandomizeSampleVector(&random_generator, capture);
+      render_delay_buffer->Insert(render);
+      filter.Update(render_delay_buffer->GetDownsampledRenderBuffer(), capture,
+                    false);
+    }
+
+    // Obtain the best lag estimate and Verify that no lag estimates are
+    // reliable.
+    auto best_lag_estimates = filter.GetBestLagEstimate();
+    EXPECT_FALSE(best_lag_estimates.has_value());
+  }
+}
+
+// Verifies that the matched filter does not produce updated lag estimates for
+// render signals of low level.
+TEST_P(MatchedFilterTest, LagNotUpdatedForLowLevelRender) {
+  const bool kDetectPreEcho = GetParam();
+  Random random_generator(42U);
+  constexpr size_t kNumChannels = 1;
+  constexpr int kSampleRateHz = 48000;
+  constexpr size_t kNumBands = NumBandsForRate(kSampleRateHz);
+
+  for (auto down_sampling_factor : kDownSamplingFactors) {
+    const size_t sub_block_size = kBlockSize / down_sampling_factor;
+
+    Block render(kNumBands, kNumChannels);
+    std::vector<std::vector<float>> capture(
+        1, std::vector<float>(kBlockSize, 0.f));
+    ApmDataDumper data_dumper(0);
+    EchoCanceller3Config config;
+    MatchedFilter filter(
+        &data_dumper, DetectOptimization(), sub_block_size,
+        kWindowSizeSubBlocks, kNumMatchedFilters, kAlignmentShiftSubBlocks, 150,
+        config.delay.delay_estimate_smoothing,
+        config.delay.delay_estimate_smoothing_delay_found,
+        config.delay.delay_candidate_detection_threshold, kDetectPreEcho);
+    std::unique_ptr<RenderDelayBuffer> render_delay_buffer(
+        RenderDelayBuffer::Create(EchoCanceller3Config(), kSampleRateHz,
+                                  kNumChannels));
+    Decimator capture_decimator(down_sampling_factor);
+
+    // Analyze the correlation between render and capture.
+    for (size_t k = 0; k < 100; ++k) {
+      RandomizeSampleVector(&random_generator, render.View(0, 0));
+      for (auto& render_k : render.View(0, 0)) {
+        render_k *= 149.f / 32767.f;
+      }
+      std::copy(render.begin(0, 0), render.end(0, 0), capture[0].begin());
+      std::array<float, kBlockSize> downsampled_capture_data;
+      rtc::ArrayView<float> downsampled_capture(downsampled_capture_data.data(),
+                                                sub_block_size);
+      capture_decimator.Decimate(capture[0], downsampled_capture);
+      filter.Update(render_delay_buffer->GetDownsampledRenderBuffer(),
+                    downsampled_capture, false);
+    }
+
+    // Verify that no lag estimate has been produced.
+    auto lag_estimate = filter.GetBestLagEstimate();
+    EXPECT_FALSE(lag_estimate.has_value());
+  }
+}
+
+INSTANTIATE_TEST_SUITE_P(_, MatchedFilterTest, testing::Values(true, false));
+
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+
+class MatchedFilterDeathTest : public ::testing::TestWithParam<bool> {};
+
+// Verifies the check for non-zero windows size.
+TEST_P(MatchedFilterDeathTest, ZeroWindowSize) {
+  const bool kDetectPreEcho = GetParam();
+  ApmDataDumper data_dumper(0);
+  EchoCanceller3Config config;
+  EXPECT_DEATH(MatchedFilter(&data_dumper, DetectOptimization(), 16, 0, 1, 1,
+                             150, config.delay.delay_estimate_smoothing,
+                             config.delay.delay_estimate_smoothing_delay_found,
+                             config.delay.delay_candidate_detection_threshold,
+                             kDetectPreEcho),
+               "");
+}
+
+// Verifies the check for non-null data dumper.
+TEST_P(MatchedFilterDeathTest, NullDataDumper) {
+  const bool kDetectPreEcho = GetParam();
+  EchoCanceller3Config config;
+  EXPECT_DEATH(MatchedFilter(nullptr, DetectOptimization(), 16, 1, 1, 1, 150,
+                             config.delay.delay_estimate_smoothing,
+                             config.delay.delay_estimate_smoothing_delay_found,
+                             config.delay.delay_candidate_detection_threshold,
+                             kDetectPreEcho),
+               "");
+}
+
+// Verifies the check for that the sub block size is a multiple of 4.
+// TODO(peah): Activate the unittest once the required code has been landed.
+TEST_P(MatchedFilterDeathTest, DISABLED_BlockSizeMultipleOf4) {
+  const bool kDetectPreEcho = GetParam();
+  ApmDataDumper data_dumper(0);
+  EchoCanceller3Config config;
+  EXPECT_DEATH(MatchedFilter(&data_dumper, DetectOptimization(), 15, 1, 1, 1,
+                             150, config.delay.delay_estimate_smoothing,
+                             config.delay.delay_estimate_smoothing_delay_found,
+                             config.delay.delay_candidate_detection_threshold,
+                             kDetectPreEcho),
+               "");
+}
+
+// Verifies the check for that there is an integer number of sub blocks that add
+// up to a block size.
+// TODO(peah): Activate the unittest once the required code has been landed.
+TEST_P(MatchedFilterDeathTest, DISABLED_SubBlockSizeAddsUpToBlockSize) {
+  const bool kDetectPreEcho = GetParam();
+  ApmDataDumper data_dumper(0);
+  EchoCanceller3Config config;
+  EXPECT_DEATH(MatchedFilter(&data_dumper, DetectOptimization(), 12, 1, 1, 1,
+                             150, config.delay.delay_estimate_smoothing,
+                             config.delay.delay_estimate_smoothing_delay_found,
+                             config.delay.delay_candidate_detection_threshold,
+                             kDetectPreEcho),
+               "");
+}
+
+INSTANTIATE_TEST_SUITE_P(_,
+                         MatchedFilterDeathTest,
+                         testing::Values(true, false));
+
+#endif
+
+}  // namespace aec3
+
+TEST(MatchedFilterFieldTrialTest, PreEchoConfigurationTest) {
+  float threshold_in = 0.1f;
+  int mode_in = 2;
+  rtc::StringBuilder field_trial_name;
+  field_trial_name << "WebRTC-Aec3PreEchoConfiguration/threshold:"
+                   << threshold_in << ",mode:" << mode_in << "/";
+  webrtc::test::ScopedFieldTrials field_trials(field_trial_name.str());
+  ApmDataDumper data_dumper(0);
+  EchoCanceller3Config config;
+  MatchedFilter matched_filter(
+      &data_dumper, DetectOptimization(),
+      kBlockSize / config.delay.down_sampling_factor,
+      aec3::kWindowSizeSubBlocks, aec3::kNumMatchedFilters,
+      aec3::kAlignmentShiftSubBlocks,
+      config.render_levels.poor_excitation_render_limit,
+      config.delay.delay_estimate_smoothing,
+      config.delay.delay_estimate_smoothing_delay_found,
+      config.delay.delay_candidate_detection_threshold,
+      config.delay.detect_pre_echo);
+
+  auto& pre_echo_config = matched_filter.GetPreEchoConfiguration();
+  EXPECT_EQ(pre_echo_config.threshold, threshold_in);
+  EXPECT_EQ(pre_echo_config.mode, mode_in);
+}
+
+TEST(MatchedFilterFieldTrialTest, WrongPreEchoConfigurationTest) {
+  constexpr float kDefaultThreshold = 0.5f;
+  constexpr int kDefaultMode = 3;
+  float threshold_in = -0.1f;
+  int mode_in = 5;
+  rtc::StringBuilder field_trial_name;
+  field_trial_name << "WebRTC-Aec3PreEchoConfiguration/threshold:"
+                   << threshold_in << ",mode:" << mode_in << "/";
+  webrtc::test::ScopedFieldTrials field_trials(field_trial_name.str());
+  ApmDataDumper data_dumper(0);
+  EchoCanceller3Config config;
+  MatchedFilter matched_filter(
+      &data_dumper, DetectOptimization(),
+      kBlockSize / config.delay.down_sampling_factor,
+      aec3::kWindowSizeSubBlocks, aec3::kNumMatchedFilters,
+      aec3::kAlignmentShiftSubBlocks,
+      config.render_levels.poor_excitation_render_limit,
+      config.delay.delay_estimate_smoothing,
+      config.delay.delay_estimate_smoothing_delay_found,
+      config.delay.delay_candidate_detection_threshold,
+      config.delay.detect_pre_echo);
+
+  auto& pre_echo_config = matched_filter.GetPreEchoConfiguration();
+  EXPECT_EQ(pre_echo_config.threshold, kDefaultThreshold);
+  EXPECT_EQ(pre_echo_config.mode, kDefaultMode);
+}
+
+}  // namespace webrtc