Added first layer of the echo canceller 3 functionality

webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc

Index: webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc
diff --git a/webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc b/webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..69a9659310ece4dc29523695d57a4c1113a9f82d
--- /dev/null
+++ b/webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc
@@ -0,0 +1,691 @@
+/*
+ *  Copyright (c) 2016 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/echo_canceller3.h"
+
+#include <deque>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <vector>
+#include <utility>

[ivoc, 2016/12/23 10:32:33]

This should be above vector.

[peah-webrtc, 2017/01/02 08:45:10]

Done.

+
+#include "webrtc/modules/audio_processing/aec3/aec3_constants.h"
+#include "webrtc/modules/audio_processing/aec3/block_processor.h"
+#include "webrtc/modules/audio_processing/aec3/frame_blocker.h"
+#include "webrtc/modules/audio_processing/aec3/mock/mock_block_processor.h"
+#include "webrtc/modules/audio_processing/audio_buffer.h"
+#include "webrtc/test/gmock.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+using testing::StrictMock;
+using testing::_;
+
+// Populates the frame with linearly increasing sample values for each band,
+// with a band-specific offset, in order to allow simple bitexactness
+// verification for each band.
+void PopulateInputFrame(size_t frame_length,
+                        size_t num_bands,
+                        size_t frame_index,
+                        float* const* frame,
+                        int offset) {
+  for (size_t k = 0; k < num_bands; ++k) {
+    for (size_t i = 0; i < frame_length; ++i) {
+      float value = static_cast<int>(frame_index * frame_length + i) + offset;
+      frame[k][i] = (value > 0 ? 5000 * k + value : 0);
+    }
+  }
+}
+
+// Verifies the that samples in the output frame are identical to the samples
+// that were produced for the input frame, with an offset in order to compensate
+// for buffering delays.
+bool VerifyOutputFrameBitexactness(size_t frame_length,
+                                   size_t num_bands,
+                                   size_t frame_index,
+                                   const float* const* frame,
+                                   int offset) {
+  float reference_frame_data[num_bands][frame_length];
+  float* reference_frame[num_bands];
+  for (size_t k = 0; k < num_bands; ++k) {
+    reference_frame[k] = &reference_frame_data[k][0];
+  }
+
+  PopulateInputFrame(frame_length, num_bands, frame_index, reference_frame,
+                     offset);
+  for (size_t k = 0; k < num_bands; ++k) {
+    for (size_t i = 0; i < frame_length; ++i) {
+      if (reference_frame[k][i] != frame[k][i]) {
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+// Class for testing that the capture data is properly received by the block
+// processor and that the processor data is properly passed to the
+// EchoCanceller3 output.
+class CaptureTransportVerificationProcessor : public BlockProcessor {
+ public:
+  explicit CaptureTransportVerificationProcessor(size_t num_bands) {}
+  ~CaptureTransportVerificationProcessor() override = default;
+
+  void ProcessCapture(bool known_echo_path_change,
+                      bool saturated_microphone_signal,
+                      std::vector<std::vector<float>>* capture_block) override {
+  }
+
+  bool BufferRender(std::vector<std::vector<float>>* block) override {
+    return false;
+  }
+
+  void ReportEchoLeakage(bool leakage_detected) override {}
+
+ private:
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(CaptureTransportVerificationProcessor);
+};
+
+// Class for testing that the render data is properly received by the block
+// processor.
+class RenderTransportVerificationProcessor : public BlockProcessor {
+ public:
+  explicit RenderTransportVerificationProcessor(size_t num_bands) {}
+  ~RenderTransportVerificationProcessor() override = default;
+
+  void ProcessCapture(bool known_echo_path_change,
+                      bool saturated_microphone_signal,
+                      std::vector<std::vector<float>>* capture_block) override {
+    std::vector<std::vector<float>> render_block =
+        received_render_blocks_.front();
+    received_render_blocks_.pop_front();
+    capture_block->swap(render_block);
+  }
+
+  bool BufferRender(std::vector<std::vector<float>>* block) override {
+    received_render_blocks_.push_back(*block);
+    return false;
+  }
+
+  void ReportEchoLeakage(bool leakage_detected) override {}
+
+ private:
+  std::deque<std::vector<std::vector<float>>> received_render_blocks_;
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(RenderTransportVerificationProcessor);
+};
+
+class EchoCanceller3Tester {
+ public:
+  explicit EchoCanceller3Tester(int sample_rate_hz)
+      : sample_rate_hz_(sample_rate_hz),
+        num_bands_(NumBandsForRate(sample_rate_hz_)),
+        frame_length_(sample_rate_hz_ == 8000 ? 80 : 160),
+        fullband_frame_length_(rtc::CheckedDivExact(sample_rate_hz_, 100)),
+        capture_buffer_(fullband_frame_length_,
+                        1,
+                        fullband_frame_length_,
+                        1,
+                        fullband_frame_length_),
+        render_buffer_(fullband_frame_length_,
+                       1,
+                       fullband_frame_length_,
+                       1,
+                       fullband_frame_length_) {}
+
+  // Verifies that the capture data is properly received by the block processor
+  // and that the processor data is properly passed to the EchoCanceller3
+  // output.
+  void RunCaptureTransportVerificationTest() {
+    EchoCanceller3 aec3(
+        sample_rate_hz_, false,
+        std::unique_ptr<BlockProcessor>(
+            new CaptureTransportVerificationProcessor(num_bands_)));
+
+    for (size_t frame_index = 0; frame_index < kNumFramesToProcess;
+         ++frame_index) {
+      aec3.AnalyzeCapture(&capture_buffer_);
+      OptionalBandSplit();
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &capture_buffer_.split_bands_f(0)[0], 0);
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &render_buffer_.split_bands_f(0)[0], 100);
+
+      EXPECT_TRUE(aec3.AnalyzeRender(&render_buffer_));
+      aec3.ProcessCapture(&capture_buffer_, false);
+      EXPECT_TRUE(VerifyOutputFrameBitexactness(
+          frame_length_, num_bands_, frame_index,
+          &capture_buffer_.split_bands_f(0)[0], -64));
+    }
+  }
+
+  // Test method for testing that the render data is properly received by the
+  // block processor.
+  void RunRenderTransportVerificationTest() {
+    EchoCanceller3 aec3(
+        sample_rate_hz_, false,
+        std::unique_ptr<BlockProcessor>(
+            new RenderTransportVerificationProcessor(num_bands_)));
+
+    for (size_t frame_index = 0; frame_index < kNumFramesToProcess;
+         ++frame_index) {
+      aec3.AnalyzeCapture(&capture_buffer_);
+      OptionalBandSplit();
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &capture_buffer_.split_bands_f(0)[0], 100);
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &render_buffer_.split_bands_f(0)[0], 0);
+
+      EXPECT_TRUE(aec3.AnalyzeRender(&render_buffer_));
+      aec3.ProcessCapture(&capture_buffer_, false);
+      EXPECT_TRUE(VerifyOutputFrameBitexactness(
+          frame_length_, num_bands_, frame_index,
+          &capture_buffer_.split_bands_f(0)[0], -64));
+    }
+  }
+
+  // Verifies that information about echo path changes are properly propagated
+  // to the block processor.
+  // The cases tested are:
+  // -That no set echo path change flags are received when there is no echo path
+  // change.
+  // -That set echo path change flags are received and continues to be received
+  // as long as echo path changes are flagged.
+  // -That set echo path change flags are no longer received when echo path
+  // change events stop being flagged.
+  enum class EchoPathChangeTestVariant { kNone, kOneSticky, kOneNonSticky };
+
+  void RunEchoPathChangeVerificationTest(
+      EchoPathChangeTestVariant echo_path_change_test_variant) {
+    const size_t num_full_blocks_per_frame =
+        rtc::CheckedDivExact(LowestBandRate(sample_rate_hz_), 100) / kBlockSize;
+    const size_t expected_num_block_to_process =
+        (kNumFramesToProcess *
+         rtc::CheckedDivExact(LowestBandRate(sample_rate_hz_), 100)) /
+        kBlockSize;
+    std::unique_ptr<testing::StrictMock<webrtc::test::MockBlockProcessor>>
+        block_processor_mock(
+            new StrictMock<webrtc::test::MockBlockProcessor>());
+    EXPECT_CALL(*block_processor_mock, BufferRender(_))
+        .Times(expected_num_block_to_process);
+    EXPECT_CALL(*block_processor_mock, ReportEchoLeakage(_)).Times(0);
+
+    switch (echo_path_change_test_variant) {
+      case EchoPathChangeTestVariant::kNone:
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(false, _, _))
+            .Times(expected_num_block_to_process);
+        break;
+      case EchoPathChangeTestVariant::kOneSticky:
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(true, _, _))
+            .Times(expected_num_block_to_process);
+        break;
+      case EchoPathChangeTestVariant::kOneNonSticky:
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(true, _, _))
+            .Times(num_full_blocks_per_frame);
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(false, _, _))
+            .Times(expected_num_block_to_process - num_full_blocks_per_frame);
+        break;
+    }
+
+    EchoCanceller3 aec3(sample_rate_hz_, false,
+                        std::move(block_processor_mock));
+
+    for (size_t frame_index = 0; frame_index < kNumFramesToProcess;
+         ++frame_index) {
+      bool echo_path_change = false;
+      switch (echo_path_change_test_variant) {
+        case EchoPathChangeTestVariant::kNone:
+          break;
+        case EchoPathChangeTestVariant::kOneSticky:
+          echo_path_change = true;
+          break;
+        case EchoPathChangeTestVariant::kOneNonSticky:
+          if (frame_index == 0) {
+            echo_path_change = true;
+          }
+          break;
+      }
+
+      aec3.AnalyzeCapture(&capture_buffer_);
+      OptionalBandSplit();
+
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &capture_buffer_.split_bands_f(0)[0], 0);
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &render_buffer_.split_bands_f(0)[0], 0);
+
+      EXPECT_TRUE(aec3.AnalyzeRender(&render_buffer_));
+      aec3.ProcessCapture(&capture_buffer_, echo_path_change);
+    }
+  }
+
+  // Test for verifying that echo leakage information is being properly passed
+  // to the processor.
+  // The cases tested are:
+  // -That no method calls are received when they should not.
+  // -That false values are received each time they are flagged.
+  // -That true values are received each time they are flagged.
+  // -That a false value is received when flagged after a true value has been
+  // flagged.
+  enum class EchoLeakageTestVariant {
+    kNone,
+    kFalseSticky,
+    kTrueSticky,
+    kTrueNonSticky
+  };
+
+  void RunEchoLeakageVerificationTest(
+      EchoLeakageTestVariant leakage_report_variant) {
+    const size_t expected_num_block_to_process =
+        (kNumFramesToProcess *
+         rtc::CheckedDivExact(LowestBandRate(sample_rate_hz_), 100)) /
+        kBlockSize;
+    std::unique_ptr<testing::StrictMock<webrtc::test::MockBlockProcessor>>
+        block_processor_mock(
+            new StrictMock<webrtc::test::MockBlockProcessor>());
+    EXPECT_CALL(*block_processor_mock, BufferRender(_))
+        .Times(expected_num_block_to_process);
+    EXPECT_CALL(*block_processor_mock, ProcessCapture(_, _, _))
+        .Times(expected_num_block_to_process);
+
+    switch (leakage_report_variant) {
+      case EchoLeakageTestVariant::kNone:
+        EXPECT_CALL(*block_processor_mock, ReportEchoLeakage(_)).Times(0);
+        break;
+      case EchoLeakageTestVariant::kFalseSticky:
+        EXPECT_CALL(*block_processor_mock, ReportEchoLeakage(false)).Times(1);
+        break;
+      case EchoLeakageTestVariant::kTrueSticky:
+        EXPECT_CALL(*block_processor_mock, ReportEchoLeakage(true)).Times(1);
+        break;
+      case EchoLeakageTestVariant::kTrueNonSticky: {
+        testing::InSequence s;
+        EXPECT_CALL(*block_processor_mock, ReportEchoLeakage(true)).Times(1);
+        EXPECT_CALL(*block_processor_mock, ReportEchoLeakage(false))
+            .Times(kNumFramesToProcess - 1);
+      } break;
+    }
+
+    EchoCanceller3 aec3(sample_rate_hz_, false,
+                        std::move(block_processor_mock));
+
+    for (size_t frame_index = 0; frame_index < kNumFramesToProcess;
+         ++frame_index) {
+      switch (leakage_report_variant) {
+        case EchoLeakageTestVariant::kNone:
+          break;
+        case EchoLeakageTestVariant::kFalseSticky:
+          if (frame_index == 0) {
+            aec3.ReportEchoLeakage(false);
+          }
+          break;
+        case EchoLeakageTestVariant::kTrueSticky:
+          if (frame_index == 0) {
+            aec3.ReportEchoLeakage(true);
+          }
+          break;
+        case EchoLeakageTestVariant::kTrueNonSticky:
+          if (frame_index == 0) {
+            aec3.ReportEchoLeakage(true);
+          } else {
+            aec3.ReportEchoLeakage(false);
+          }
+          break;
+      }
+
+      aec3.AnalyzeCapture(&capture_buffer_);
+      OptionalBandSplit();
+
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &capture_buffer_.split_bands_f(0)[0], 0);
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &render_buffer_.split_bands_f(0)[0], 0);
+
+      EXPECT_TRUE(aec3.AnalyzeRender(&render_buffer_));
+      aec3.ProcessCapture(&capture_buffer_, false);
+    }
+  }
+
+  // This verifies that saturation information is properly passed to the
+  // BlockProcessor.
+  // The cases tested are:
+  // -That no saturation event is passed to the processor if there is no
+  // saturation.
+  // -That one frame with one negative saturated sample value is reported to be
+  // saturated and that following non-saturated frames are properly reported as
+  // not being saturated.
+  // -That one frame with one positive saturated sample value is reported to be
+  // saturated and that following non-saturated frames are properly reported as
+  // not being saturated.
+  enum class SaturationTestVariant { kNone, kOneNegative, kOnePositive };
+
+  void RunCaptureSaturationVerificationTest(
+      SaturationTestVariant saturation_variant) {
+    const size_t num_full_blocks_per_frame =
+        rtc::CheckedDivExact(LowestBandRate(sample_rate_hz_), 100) / kBlockSize;
+    const size_t expected_num_block_to_process =
+        (kNumFramesToProcess *
+         rtc::CheckedDivExact(LowestBandRate(sample_rate_hz_), 100)) /
+        kBlockSize;
+    std::unique_ptr<testing::StrictMock<webrtc::test::MockBlockProcessor>>
+        block_processor_mock(
+            new StrictMock<webrtc::test::MockBlockProcessor>());
+    EXPECT_CALL(*block_processor_mock, BufferRender(_))
+        .Times(expected_num_block_to_process);
+    EXPECT_CALL(*block_processor_mock, ReportEchoLeakage(_)).Times(0);
+
+    switch (saturation_variant) {
+      case SaturationTestVariant::kNone:
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, false, _))
+            .Times(expected_num_block_to_process);
+        break;
+      case SaturationTestVariant::kOneNegative: {
+        testing::InSequence s;
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, true, _))
+            .Times(num_full_blocks_per_frame);
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, false, _))
+            .Times(expected_num_block_to_process - num_full_blocks_per_frame);
+      } break;
+      case SaturationTestVariant::kOnePositive: {
+        testing::InSequence s;
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, true, _))
+            .Times(num_full_blocks_per_frame);
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, false, _))
+            .Times(expected_num_block_to_process - num_full_blocks_per_frame);
+      } break;
+    }
+
+    EchoCanceller3 aec3(sample_rate_hz_, false,
+                        std::move(block_processor_mock));
+
+    for (size_t frame_index = 0; frame_index < kNumFramesToProcess;
+         ++frame_index) {
+      for (int k = 0; k < fullband_frame_length_; ++k) {
+        capture_buffer_.channels_f()[0][k] = 0.f;
+      }
+      switch (saturation_variant) {
+        case SaturationTestVariant::kNone:
+          break;
+        case SaturationTestVariant::kOneNegative:
+          if (frame_index == 0) {
+            capture_buffer_.channels_f()[0][10] = -32768.f;
+          }
+          break;
+        case SaturationTestVariant::kOnePositive:
+          if (frame_index == 0) {
+            capture_buffer_.channels_f()[0][10] = 32767.f;
+          }
+          break;
+      }
+
+      aec3.AnalyzeCapture(&capture_buffer_);
+      OptionalBandSplit();
+
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &capture_buffer_.split_bands_f(0)[0], 0);
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &render_buffer_.split_bands_f(0)[0], 0);
+
+      EXPECT_TRUE(aec3.AnalyzeRender(&render_buffer_));
+      aec3.ProcessCapture(&capture_buffer_, false);
+    }
+  }
+
+  // This test verifies that the swapqueue is able to handle jitter in the
+  // capture and render API calls.
+  void RunRenderSwapQueueVerificationTest() {
+    EchoCanceller3 aec3(
+        sample_rate_hz_, false,
+        std::unique_ptr<BlockProcessor>(
+            new RenderTransportVerificationProcessor(num_bands_)));
+
+    constexpr size_t kSwapQueueLength = 30;
+    for (size_t frame_index = 0; frame_index < kSwapQueueLength;
+         ++frame_index) {
+      if (sample_rate_hz_ > 16000) {
+        render_buffer_.SplitIntoFrequencyBands();
+      }
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &render_buffer_.split_bands_f(0)[0], 0);
+
+      EXPECT_TRUE(aec3.AnalyzeRender(&render_buffer_));
+    }
+
+    for (size_t frame_index = 0; frame_index < kSwapQueueLength;
+         ++frame_index) {
+      aec3.AnalyzeCapture(&capture_buffer_);
+      if (sample_rate_hz_ > 16000) {
+        capture_buffer_.SplitIntoFrequencyBands();
+      }
+
+      PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                         &capture_buffer_.split_bands_f(0)[0], 0);
+
+      aec3.ProcessCapture(&capture_buffer_, false);
+      EXPECT_TRUE(VerifyOutputFrameBitexactness(
+          frame_length_, num_bands_, frame_index,
+          &capture_buffer_.split_bands_f(0)[0], -64));
+    }
+  }
+
+  // This test verifies that a buffer overrun in the render swapqueue is
+  // properly reported.
+  void RunRenderPipelineSwapQueueOverrunReturnValueTest() {
+    EchoCanceller3 aec3(sample_rate_hz_, false);
+
+    constexpr size_t kSwapQueueLength = 30;
+    for (size_t k = 0; k < 2; ++k) {
+      for (size_t frame_index = 0; frame_index < kSwapQueueLength;
+           ++frame_index) {
+        if (sample_rate_hz_ > 16000) {
+          render_buffer_.SplitIntoFrequencyBands();
+        }
+        PopulateInputFrame(frame_length_, num_bands_, frame_index,
+                           &render_buffer_.split_bands_f(0)[0], 0);
+
+        if (k == 0) {
+          EXPECT_TRUE(aec3.AnalyzeRender(&render_buffer_));
+        } else {
+          EXPECT_FALSE(aec3.AnalyzeRender(&render_buffer_));
+        }
+      }
+    }
+  }
+
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+  // Verifies the that the check for the number of bands in the AnalyzeRender
+  // input is correct by adjusting the sample rates of EchoCanceller3 and the
+  // input AudioBuffer to have a different number of bands.
+  void RunAnalyzeRenderNumBandsCheckVerification() {
+    const int aec3_sample_rate_hz = sample_rate_hz_ == 48000 ? 32000 : 48000;

[ivoc, 2016/12/23 10:32:33]

Is this correct? I think the other way around would make more sense (48000 ?
48000 : 32000)

[peah-webrtc, 2017/01/02 08:45:10]

It is correct, but since this statement is very misleading I now added a
comment.
The purpose of that assignment is to ensure that aec3_sample_rate_hz is such
that the corresponding number of bands is different from what is the case for
sample_rate_hz_. That is accomplished by forcing aec3_sample_rate_hz to 48000 in
all cases except for when sample_rate_hz_ is 48000, in which case
aec3_sample_rate_hz is forced to 32000.

Done.

[ivoc, 2017/01/02 10:17:11]

Great, it's much easier to understand what's going on now.

+    EchoCanceller3 aec3(aec3_sample_rate_hz, false);
+    PopulateInputFrame(frame_length_, num_bands_, 0,
+                       &render_buffer_.split_bands_f(0)[0], 0);
+
+    EXPECT_DEATH(aec3.AnalyzeRender(&render_buffer_), "");
+  }
+
+  // Verifies the that the check for the number of bands in the ProcessCapture
+  // input is correct by adjusting the sample rates of EchoCanceller3 and the
+  // input AudioBuffer to have a different number of bands.
+  void RunProcessCaptureNumBandsCheckVerification() {
+    const int aec3_sample_rate_hz = sample_rate_hz_ == 48000 ? 32000 : 48000;

[ivoc, 2016/12/23 10:32:33]

Same here

[peah-webrtc, 2017/01/02 08:45:10]

Added comment, see above for details. 

Done.

[ivoc, 2017/01/02 10:17:11]

Acknowledged.

+    EchoCanceller3 aec3(aec3_sample_rate_hz, false);
+    PopulateInputFrame(frame_length_, num_bands_, 0,
+                       &capture_buffer_.split_bands_f(0)[0], 100);
+    EXPECT_DEATH(aec3.ProcessCapture(&capture_buffer_, false), "");
+  }
+
+  // Verifies the that the check for the frame length in the AnalyzeRender input
+  // is correct by adjusting the sample rates of EchoCanceller3 and the input
+  // AudioBuffer to have a different frame lengths.
+  void RunAnalyzeRenderFrameLengthCheckVerification() {
+    const int aec3_sample_rate_hz = sample_rate_hz_ == 8000 ? 16000 : 8000;

[ivoc, 2016/12/23 10:32:33]

And here

[peah-webrtc, 2017/01/02 08:45:10]

The idea here is to choose aec3_sample_rate_hz such that the frame length (in
each band) becomes different than what it is for sample_rate_hz_. As the frame
length is 80 samples for 8 kHz, and 160 samples otherwise, this can only be
accomplished by forcing aec3_sample_rate_hz to be 8 kHz in all cases apart from
when sample_rate_hz_ is 8 kHz.

I added a comment since this is not at all obvious.

Done.

[ivoc, 2017/01/02 10:17:11]

Acknowledged.

+    EchoCanceller3 aec3(aec3_sample_rate_hz, false);
+
+    OptionalBandSplit();
+    PopulateInputFrame(frame_length_, num_bands_, 0,
+                       &render_buffer_.split_bands_f(0)[0], 0);
+
+    EXPECT_DEATH(aec3.AnalyzeRender(&render_buffer_), "");
+  }
+
+  // Verifies the that the check for the frame length in the AnalyzeRender input
+  // is correct by adjusting the sample rates of EchoCanceller3 and the input
+  // AudioBuffer to have a different frame lengths.
+  void RunProcessCaptureFrameLengthCheckVerification() {
+    const int aec3_sample_rate_hz = sample_rate_hz_ == 8000 ? 16000 : 8000;

[ivoc, 2016/12/23 10:32:33]

And here

[peah-webrtc, 2017/01/02 08:45:10]

Added comment, see above for details. 

Done.

[ivoc, 2017/01/02 10:17:11]

I don't see a comment here, it would be nice to have one as well.

[peah-webrtc, 2017/01/02 10:25:26]

Ah! Sorry, missed to add that one. Thanks!

Done.

+    EchoCanceller3 aec3(aec3_sample_rate_hz, false);
+
+    OptionalBandSplit();
+    PopulateInputFrame(frame_length_, num_bands_, 0,
+                       &capture_buffer_.split_bands_f(0)[0], 100);
+
+    EXPECT_DEATH(aec3.ProcessCapture(&capture_buffer_, false), "");
+  }
+
+#endif
+
+ private:
+  void OptionalBandSplit() {
+    if (sample_rate_hz_ > 16000) {
+      capture_buffer_.SplitIntoFrequencyBands();
+      render_buffer_.SplitIntoFrequencyBands();
+    }
+  }
+
+  static constexpr size_t kNumFramesToProcess = 20;
+  const int sample_rate_hz_;
+  const size_t num_bands_;
+  const size_t frame_length_;
+  const int fullband_frame_length_;
+  AudioBuffer capture_buffer_;
+  AudioBuffer render_buffer_;
+
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(EchoCanceller3Tester);
+};
+
+std::string ProduceDebugText(int sample_rate_hz) {
+  std::ostringstream ss;
+  ss << "Sample rate: " << sample_rate_hz;
+  return ss.str();
+}
+
+std::string ProduceDebugText(int sample_rate_hz, int variant) {
+  std::ostringstream ss;
+  ss << "Sample rate: " << sample_rate_hz << ", variant: " << variant;
+  return ss.str();
+}
+
+}  // namespace
+
+TEST(EchoCanceller3Buffering, CaptureBitexactness) {
+  for (auto rate : {8000, 16000, 32000, 48000}) {
+    SCOPED_TRACE(ProduceDebugText(rate));
+    EchoCanceller3Tester(rate).RunCaptureTransportVerificationTest();
+  }
+}
+
+TEST(EchoCanceller3Buffering, RenderBitexactness) {
+  for (auto rate : {8000, 16000, 32000, 48000}) {
+    SCOPED_TRACE(ProduceDebugText(rate));
+    EchoCanceller3Tester(rate).RunRenderTransportVerificationTest();
+  }
+}
+
+TEST(EchoCanceller3Buffering, RenderSwapQueue) {
+  for (auto rate : {8000, 16000, 32000, 48000}) {
+    SCOPED_TRACE(ProduceDebugText(rate));
+    EchoCanceller3Tester(rate).RunRenderSwapQueueVerificationTest();
+  }
+}
+
+TEST(EchoCanceller3Buffering, RenderSwapQueueOverrunReturnValue) {
+  for (auto rate : {8000, 16000, 32000, 48000}) {
+    SCOPED_TRACE(ProduceDebugText(rate));
+    EchoCanceller3Tester(rate)
+        .RunRenderPipelineSwapQueueOverrunReturnValueTest();
+  }
+}
+
+TEST(EchoCanceller3Messaging, CaptureSaturation) {
+  auto variants = {EchoCanceller3Tester::SaturationTestVariant::kNone,
+                   EchoCanceller3Tester::SaturationTestVariant::kOneNegative,
+                   EchoCanceller3Tester::SaturationTestVariant::kOnePositive};
+  for (auto rate : {8000, 16000, 32000, 48000}) {
+    for (auto variant : variants) {
+      SCOPED_TRACE(ProduceDebugText(rate, static_cast<int>(variant)));
+      EchoCanceller3Tester(rate).RunCaptureSaturationVerificationTest(variant);
+    }
+  }
+}
+
+TEST(EchoCanceller3Messaging, EchoPathChange) {
+  auto variants = {
+      EchoCanceller3Tester::EchoPathChangeTestVariant::kNone,
+      EchoCanceller3Tester::EchoPathChangeTestVariant::kOneSticky,
+      EchoCanceller3Tester::EchoPathChangeTestVariant::kOneNonSticky};
+  for (auto rate : {8000, 16000, 32000, 48000}) {
+    for (auto variant : variants) {
+      SCOPED_TRACE(ProduceDebugText(rate, static_cast<int>(variant)));
+      EchoCanceller3Tester(rate).RunEchoPathChangeVerificationTest(variant);
+    }
+  }
+}
+
+TEST(EchoCanceller3Messaging, EchoLeakage) {
+  auto variants = {
+      EchoCanceller3Tester::EchoLeakageTestVariant::kNone,
+      EchoCanceller3Tester::EchoLeakageTestVariant::kFalseSticky,
+      EchoCanceller3Tester::EchoLeakageTestVariant::kTrueSticky,
+      EchoCanceller3Tester::EchoLeakageTestVariant::kTrueNonSticky};
+  for (auto rate : {8000, 16000, 32000, 48000}) {
+    for (auto variant : variants) {
+      SCOPED_TRACE(ProduceDebugText(rate, static_cast<int>(variant)));
+      EchoCanceller3Tester(rate).RunEchoLeakageVerificationTest(variant);
+    }
+  }
+}
+
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+TEST(EchoCanceller3InputCheck, WrongRenderNumBandsCheckVerification) {
+  for (auto rate : {8000, 16000, 32000, 48000}) {
+    SCOPED_TRACE(ProduceDebugText(rate));
+    EchoCanceller3Tester(rate).RunAnalyzeRenderNumBandsCheckVerification();
+  }
+}
+
+TEST(EchoCanceller3InputCheck, WrongCaptureNumBandsCheckVerification) {
+  for (auto rate : {8000, 16000, 32000, 48000}) {
+    SCOPED_TRACE(ProduceDebugText(rate));
+    EchoCanceller3Tester(rate).RunProcessCaptureNumBandsCheckVerification();
+  }
+}
+
+TEST(EchoCanceller3InputCheck, WrongRenderFrameLengthCheckVerification) {
+  for (auto rate : {8000, 16000}) {
+    SCOPED_TRACE(ProduceDebugText(rate));
+    EchoCanceller3Tester(rate).RunAnalyzeRenderFrameLengthCheckVerification();
+  }
+}
+
+TEST(EchoCanceller3InputCheck, WrongCaptureFrameLengthCheckVerification) {
+  for (auto rate : {8000, 16000}) {
+    SCOPED_TRACE(ProduceDebugText(rate));
+    EchoCanceller3Tester(rate).RunProcessCaptureFrameLengthCheckVerification();
+  }
+}
+
+#endif
+
+}  // namespace webrtc