Adding full initial version of delay estimation functionality in echo canceller 3

webrtc/modules/audio_processing/aec3/correlator_unittest.cc

Index: webrtc/modules/audio_processing/aec3/correlator_unittest.cc
diff --git a/webrtc/modules/audio_processing/aec3/correlator_unittest.cc b/webrtc/modules/audio_processing/aec3/correlator_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..daca956893460c89357ffed5ad523e006e3d76d2
--- /dev/null
+++ b/webrtc/modules/audio_processing/aec3/correlator_unittest.cc
@@ -0,0 +1,213 @@
+/*
+ *  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/correlator.h"
+
+#include <algorithm>
+#include <sstream>
+#include <string>
+
+#include "webrtc/modules/audio_processing/aec3/aec3_constants.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 {
+
+std::string ProduceDebugText(size_t delay) {
+  std::ostringstream ss;
+  ss << "Delay: " << delay;
+  return ss.str();
+}
+
+}  // namespace
+
+// Verifies that the correlator produces proper lag estimates for artificially
+// delayed signals.
+TEST(Correlator, LagEstimation) {
+  Random random_generator(42U);
+  std::vector<float> render(kSubBlockSize, 0.f);
+  std::vector<float> capture(kSubBlockSize, 0.f);
+  ApmDataDumper data_dumper(0);
+  for (size_t delay_samples : {0, 64, 150, 200, 800, 1000}) {
+    SCOPED_TRACE(ProduceDebugText(delay_samples));
+    DelayBuffer<float> signal_delay_buffer(delay_samples);
+    constexpr size_t kWindowSizeSubBlocks = 32;
+    constexpr size_t kAlignmentShiftSubBlocks = kWindowSizeSubBlocks * 3 / 4;
+    constexpr size_t kNumAlignmentShifts = 3;
+    Correlator correlator(&data_dumper, kWindowSizeSubBlocks,
+                          kNumAlignmentShifts, kAlignmentShiftSubBlocks);
+
+    // Analyze the correlation between render and capture.
+    for (size_t k = 0; k < (100 + delay_samples / kSubBlockSize); ++k) {
+      RandomizeSampleVector(&random_generator, render);
+      signal_delay_buffer.Delay(render, capture);
+      correlator.Update(render, capture);
+    }
+
+    // Obtain the lag estimates.
+    rtc::ArrayView<const Correlator::LagEstimate> lag_estimates =

[hlundin-webrtc, 2017/02/01 08:30:01]

auto

[peah-webrtc, 2017/02/02 14:04:46]

Done.

+        correlator.GetLagEstimates();
+    EXPECT_EQ(kNumAlignmentShifts + 1, lag_estimates.size());

[hlundin-webrtc, 2017/02/01 08:30:01]

You are already checking this explicitly in a test below. So you don't have to
check this in all other tests too.

[peah-webrtc, 2017/02/02 14:04:46]

Done.

+
+    // Find which lag estimate should be the most accurate.
+    rtc::Optional<size_t> expected_most_accurate_lag_estimate;
+    size_t alignment_shift_sub_blocks = 0;
+    for (size_t k = 0; k < kNumAlignmentShifts; ++k) {
+      if ((alignment_shift_sub_blocks + kWindowSizeSubBlocks / 2) *
+              kSubBlockSize >
+          delay_samples) {
+        expected_most_accurate_lag_estimate = rtc::Optional<size_t>(k);
+        break;
+      }
+      alignment_shift_sub_blocks += kAlignmentShiftSubBlocks;
+    }
+    RTC_DCHECK(expected_most_accurate_lag_estimate);

[hlundin-webrtc, 2017/02/01 08:30:01]

ASSERT_TRUE

[peah-webrtc, 2017/02/02 14:04:46]

Done.

+
+    // Verify that the expected most accurate lag estimate is the most accurate
+    // estimate.
+    for (size_t k = 0; k < kNumAlignmentShifts; ++k) {
+      if (k != static_cast<size_t>(*expected_most_accurate_lag_estimate)) {

[hlundin-webrtc, 2017/02/01 08:30:01]

Why the cast?

[peah-webrtc, 2017/02/02 14:04:46]

Done.

+        EXPECT_GT(lag_estimates[*expected_most_accurate_lag_estimate].accuracy,
+                  lag_estimates[k].accuracy);
+      }
+    }
+
+    // Verify that all lag estimates are updated as expected for signals
+    // containing strong noise.
+    for (size_t k = 0; k < kNumAlignmentShifts; ++k) {
+      EXPECT_TRUE(lag_estimates[k].updated);
+    }
+
+    // Verify that the expected most accurate lag estimate is reliable.
+    EXPECT_TRUE(lag_estimates[*expected_most_accurate_lag_estimate].reliable);
+
+    // Verify that the expected most accurate lag estimate is correct.
+    EXPECT_EQ(delay_samples,
+              lag_estimates[*expected_most_accurate_lag_estimate].lag);
+  }
+}
+
+// Verifies that the correlator does not produce reliable and accurate estimates
+// for uncorrelated render and capture signals.
+TEST(Correlator, LagNotUpdatedForLowLevelRender) {
+  Random random_generator(42U);
+  std::vector<float> render(kSubBlockSize, 0.f);
+  std::vector<float> capture(kSubBlockSize, 0.f);
+  ApmDataDumper data_dumper(0);
+  constexpr size_t kWindowSizeSubBlocks = 32;
+  constexpr size_t kAlignmentShiftSubBlocks = kWindowSizeSubBlocks * 3 / 4;
+  constexpr size_t kNumAlignmentShifts = 3;
+  Correlator correlator(&data_dumper, kWindowSizeSubBlocks, kNumAlignmentShifts,
+                        kAlignmentShiftSubBlocks);
+
+  // Analyze the correlation between render and capture.
+  for (size_t k = 0; k < 100; ++k) {
+    RandomizeSampleVector(&random_generator, render);
+    RandomizeSampleVector(&random_generator, capture);
+    correlator.Update(render, capture);
+  }
+
+  // Obtain the lag estimates.
+  rtc::ArrayView<const Correlator::LagEstimate> lag_estimates =
+      correlator.GetLagEstimates();
+  EXPECT_EQ(kNumAlignmentShifts + 1, lag_estimates.size());
+
+  // Verify that no lag estimates are reliable.
+  for (size_t k = 0; k < kNumAlignmentShifts; ++k) {

[hlundin-webrtc, 2017/02/01 08:30:01]

for (auto le : lag_estimates) {
  EXPECT_FALSE(le.reliable);
}

[peah-webrtc, 2017/02/02 14:04:46]

Done.

[aleloi, 2017/02/02 16:33:11]

That's not equivalent. lag_estimates has kNumAlignmentShift + 1 elements, but
the previous loop checks kNumAlignmentShift.

[peah-webrtc, 2017/02/03 06:59:59]

You are correct. I mixed this up. It is now corrected.
PTAL

+    EXPECT_FALSE(lag_estimates[k].reliable);
+  }
+}
+
+// Verifies that the correlator does not produce updated lag estimates for
+// render signals of low level.
+TEST(Correlator, LagNotReliableForUncorrelatedRenderAndCapture) {
+  Random random_generator(42U);
+  std::vector<float> render(kSubBlockSize, 0.f);
+  std::vector<float> capture(kSubBlockSize, 0.f);
+  ApmDataDumper data_dumper(0);
+  constexpr size_t kWindowSizeSubBlocks = 32;

[hlundin-webrtc, 2017/02/01 08:30:01]

These constexprs are the same for all tests. Consider putting them on top of the
file.

[peah-webrtc, 2017/02/02 14:04:46]

Done.

+  constexpr size_t kAlignmentShiftSubBlocks = kWindowSizeSubBlocks * 3 / 4;
+  constexpr size_t kNumAlignmentShifts = 3;
+  Correlator correlator(&data_dumper, kWindowSizeSubBlocks, kNumAlignmentShifts,
+                        kAlignmentShiftSubBlocks);
+
+  // Analyze the correlation between render and capture.
+  for (size_t k = 0; k < 100; ++k) {
+    RandomizeSampleVector(&random_generator, render);
+    for (auto& render_k : render) {
+      render_k *= 149.f / 32767.f;
+    }
+    std::copy(render.begin(), render.end(), capture.begin());
+    correlator.Update(render, capture);
+  }
+
+  // Obtain the lag estimates.
+  rtc::ArrayView<const Correlator::LagEstimate> lag_estimates =
+      correlator.GetLagEstimates();
+  EXPECT_EQ(kNumAlignmentShifts + 1, lag_estimates.size());
+
+  // Verify that no lag estimates are updated.
+  for (size_t k = 0; k < kNumAlignmentShifts; ++k) {

[hlundin-webrtc, 2017/02/01 08:30:01]

Consider range-based. Also, you can merge this and the next loop into one.

[peah-webrtc, 2017/02/02 14:04:46]

Done.

+    EXPECT_FALSE(lag_estimates[k].updated);
+  }
+
+  // Verify that no lag estimates are reliable.
+  for (size_t k = 0; k < kNumAlignmentShifts; ++k) {
+    EXPECT_FALSE(lag_estimates[k].reliable);
+  }
+}
+
+// Verifies that the correct number of lag estimates are produced for a certain
+// number of alignment shifts.
+TEST(Correlator, NumberOfLagEstimates) {
+  ApmDataDumper data_dumper(0);
+  for (size_t num_alignment_shifts = 0; num_alignment_shifts < 10;
+       ++num_alignment_shifts) {
+    Correlator correlator(&data_dumper, 32, num_alignment_shifts, 1);
+    EXPECT_EQ(num_alignment_shifts + 1, correlator.GetLagEstimates().size());
+  }
+}
+
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+
+// Verifies the check for the render signal sub block size.
+TEST(Correlator, WrongRenderSize) {
+  std::vector<float> render(kSubBlockSize - 1, 0.f);
+  std::vector<float> capture(kSubBlockSize, 0.f);
+  ApmDataDumper data_dumper(0);
+  Correlator correlator(&data_dumper, 1, 1, 1);
+  EXPECT_DEATH(correlator.Update(render, capture), "");
+}
+
+// Verifies the check for the capture signal sub block size.
+TEST(Correlator, WrongCaptureSize) {
+  std::vector<float> render(kSubBlockSize, 0.f);
+  std::vector<float> capture(kSubBlockSize - 1, 0.f);
+  ApmDataDumper data_dumper(0);
+  Correlator correlator(&data_dumper, 1, 1, 1);
+  EXPECT_DEATH(correlator.Update(render, capture), "");
+}
+
+// Verifies the check for non-zero windows size.
+TEST(Correlator, ZeroWindowSize) {
+  ApmDataDumper data_dumper(0);
+  EXPECT_DEATH(Correlator(&data_dumper, 0, 1, 1), "");
+}
+
+// Verifies the check for non-null data dumper.
+TEST(Correlator, NullDataDumper) {
+  EXPECT_DEATH(Correlator(nullptr, 1, 1, 1), "");
+}
+
+#endif
+
+}  // namespace webrtc