Added a bitexactness test for the echo canceller in the audio processing module.

webrtc/modules/audio_processing/echo_cancellation_unittest.cc

+/*
+ *  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 <vector>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/array_view.h"
+#include "webrtc/modules/audio_processing/audio_buffer.h"
+#include "webrtc/modules/audio_processing/echo_cancellation_impl.h"
+#include "webrtc/modules/audio_processing/test/audio_buffer_tools.h"
+#include "webrtc/modules/audio_processing/test/bitexactness_tools.h"
+
+namespace webrtc {
+namespace {
+
+const int kNumFramesToProcess = 1000;
+
+void SetupComponent(int sample_rate_hz,
+                    EchoCancellation::SuppressionLevel suppression_level,
+                    bool drift_compensation_enabled,
+                    EchoCancellationImpl* echo_canceller) {
+  echo_canceller->Initialize(sample_rate_hz, 1, 1, 1);
+  static_cast<EchoCancellation*>(echo_canceller)->Enable(true);

[hlundin-webrtc, 2016/03/18 08:17:47]

Consider:
EchoCancellation* ec = static_cast<EchoCancellation*>(echo_canceller);
ec->Enable(true);
...

You decide if it makes the code any prettier.

[peah-webrtc, 2016/03/20 21:23:16]

Done.

+  static_cast<EchoCancellation*>(echo_canceller)
+      ->set_suppression_level(suppression_level);
+  static_cast<EchoCancellation*>(echo_canceller)
+      ->enable_drift_compensation(drift_compensation_enabled);
+
+  Config config;
+  config.Set<DelayAgnostic>(new DelayAgnostic(true));
+  config.Set<ExtendedFilter>(new ExtendedFilter(true));
+  echo_canceller->SetExtraOptions(config);
+}
+
+void ProcessOneFrame(int sample_rate_hz,
+                     int stream_delay_ms,
+                     bool drift_compensation_enabled,
+                     int stream_drift_samples,
+                     AudioBuffer* render_audio_buffer,
+                     AudioBuffer* capture_audio_buffer,
+                     EchoCancellationImpl* echo_canceller) {
+  if (sample_rate_hz > AudioProcessing::kSampleRate16kHz) {
+    render_audio_buffer->SplitIntoFrequencyBands();
+    capture_audio_buffer->SplitIntoFrequencyBands();
+  }
+
+  echo_canceller->ProcessRenderAudio(render_audio_buffer);
+
+  if (drift_compensation_enabled) {
+    static_cast<EchoCancellation*>(echo_canceller)

[hlundin-webrtc, 2016/03/18 08:17:47]

Does this have to be set for every frame processed?

[peah-webrtc, 2016/03/20 21:24:09]

Yes, that is the case.

+        ->set_stream_drift_samples(stream_drift_samples);
+  }
+
+  echo_canceller->ProcessCaptureAudio(capture_audio_buffer, stream_delay_ms);
+
+  if (sample_rate_hz > AudioProcessing::kSampleRate16kHz) {
+    capture_audio_buffer->MergeFrequencyBands();
+  }
+}
+
+void RunBitexactnessTest(int sample_rate_hz,
+                         size_t num_channels,
+                         int stream_delay_ms,
+                         bool drift_compensation_enabled,
+                         int stream_drift_samples,
+                         EchoCancellation::SuppressionLevel suppression_level,
+                         bool stream_has_echo_reference,
+                         const rtc::ArrayView<const float>& output_reference) {
+  rtc::CriticalSection crit_render;
+  rtc::CriticalSection crit_capture;
+  EchoCancellationImpl echo_canceller(&crit_render, &crit_capture);
+  SetupComponent(sample_rate_hz, suppression_level, drift_compensation_enabled,
+                 &echo_canceller);
+
+  int samples_per_channel = rtc::CheckedDivExact(sample_rate_hz, 100);

[hlundin-webrtc, 2016/03/18 08:17:47]

const

[peah-webrtc, 2016/03/20 21:24:10]

Done.

+  const StreamConfig render_config(sample_rate_hz, num_channels, false);
+  AudioBuffer render_buffer(
+      render_config.num_frames(), render_config.num_channels(),
+      render_config.num_frames(), 1, render_config.num_frames());
+  test::InputAudioFile render_file(
+      test::GetApmRenderTestVectorFileName(sample_rate_hz));
+  std::vector<float> render_input(samples_per_channel * num_channels);
+
+  const StreamConfig capture_config(sample_rate_hz, num_channels, false);
+  AudioBuffer capture_buffer(
+      capture_config.num_frames(), capture_config.num_channels(),
+      capture_config.num_frames(), 1, capture_config.num_frames());
+  test::InputAudioFile capture_file(
+      test::GetApmCaptureTestVectorFileName(sample_rate_hz));
+  std::vector<float> capture_input(samples_per_channel * num_channels);
+
+  for (int frame_no = 0; frame_no < kNumFramesToProcess; ++frame_no) {
+    ReadFloatSamplesFromStereoFile(samples_per_channel, num_channels,
+                                   &render_file, render_input);
+    ReadFloatSamplesFromStereoFile(samples_per_channel, num_channels,
+                                   &capture_file, capture_input);
+
+    test::CopyVectorToAudioBuffer(render_config, render_input, &render_buffer);
+    test::CopyVectorToAudioBuffer(capture_config, capture_input,
+                                  &capture_buffer);
+
+    ProcessOneFrame(sample_rate_hz, stream_delay_ms, drift_compensation_enabled,
+                    stream_drift_samples, &render_buffer, &capture_buffer,
+                    &echo_canceller);
+  }
+
+  // Extract and verify the test results.
+  std::vector<float> capture_output;
+  test::ExtractVectorFromAudioBuffer(capture_config, &capture_buffer,
+                                     &capture_output);
+  bool stream_has_echo =
+      static_cast<EchoCancellation*>(&echo_canceller)->stream_has_echo();
+
+  const float kTolerance = 1.0f / 32768.0f;

[hlundin-webrtc, 2016/03/18 08:17:47]

Move to just before the line where it is used.

[peah-webrtc, 2016/03/20 21:24:09]

Done.

+  EXPECT_EQ(stream_has_echo_reference, stream_has_echo);

[hlundin-webrtc, 2016/03/18 08:17:47]

EXPECT_EQ(stream_has_echo_reference,
static_cast<EchoCancellation*>(&echo_canceller)->stream_has_echo());

[peah-webrtc, 2016/03/20 21:24:09]

Done.

+
+  // Compare the output with the reference. Only the first values of the output
+  // from last frame processed are compared in order not having to specify all
+  // preceeding frames as testvectors. As the algorithm being tested has a
+  // memory, testing only the last frame implicitly also tests the preceeding
+  // frames.
+  EXPECT_TRUE(test::BitExactFrame(
+      capture_config.num_frames(), capture_config.num_channels(),
+      output_reference, capture_output, kTolerance));
+}
+
+}  // namespace
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono8kHz_HighLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {0.005739f, 0.009969f, 0.013096f};
+
+  RunBitexactnessTest(8000, 1, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono16kHz_HighLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {-0.017875f, -0.016454f, -0.014657f};
+
+  RunBitexactnessTest(16000, 1, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono32kHz_HighLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {-0.020294f, -0.020081f, -0.019135f};
+
+  RunBitexactnessTest(32000, 1, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono48kHz_HighLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {-0.016347f, -0.016763f, -0.017036f};
+
+  RunBitexactnessTest(48000, 1, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono16kHz_LowLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {-0.018289f, -0.016901f, -0.015122f};
+
+  RunBitexactnessTest(16000, 1, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kLowSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono16kHz_ModerateLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {-0.018194f, -0.016788f, -0.014997f};
+
+  RunBitexactnessTest(16000, 1, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kModerateSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono16kHz_HighLevel_NoDrift_StreamDelay10) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {-0.017875f, -0.016454f, -0.014657f};
+
+  RunBitexactnessTest(16000, 1, 10, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono16kHz_HighLevel_NoDrift_StreamDelay20) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {-0.017875f, -0.016454f, -0.014657f};
+
+  RunBitexactnessTest(16000, 1, 20, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono16kHz_HighLevel_Drift0_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {-0.017875f, -0.016454f, -0.014657f};
+
+  RunBitexactnessTest(16000, 1, 0, true, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Mono16kHz_HighLevel_Drift5_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {-0.017875f, -0.016454f, -0.014657f};
+
+  RunBitexactnessTest(16000, 1, 0, true, 5,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Stereo8kHz_HighLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {0.011691f, 0.004257f, 0.010092f,
+                                    0.011691f, 0.004257f, 0.010092f};
+
+  RunBitexactnessTest(8000, 2, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Stereo16kHz_HighLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {0.000677f, 0.006431f, -0.000613f,
+                                    0.000677f, 0.006431f, -0.000613f};
+
+  RunBitexactnessTest(16000, 2, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Stereo32kHz_HighLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {0.001526f, 0.007630f, 0.001007f,
+                                    0.001526f, 0.007630f, 0.001007f};
+
+  RunBitexactnessTest(32000, 2, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+TEST(EchoCancellationBitExactnessTest,
+     Stereo48kHz_HighLevel_NoDrift_StreamDelay0) {
+  const bool kStreamHasEchoReference = false;
+  const float kOutputReference[] = {0.004390f, 0.011286f, 0.004254f,
+                                    0.004390f, 0.011286f, 0.004254f};
+
+  RunBitexactnessTest(48000, 2, 0, false, 0,
+                      EchoCancellation::SuppressionLevel::kHighSuppression,
+                      kStreamHasEchoReference, kOutputReference);
+}
+
+}  // namespace webrtc