modules/audio_coding/neteq/delay_manager_unittest.cc - src - Git at Google

 /*
  *  Copyright (c) 2012 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.
  */

 // Unit tests for DelayManager class.

 #include "modules/audio_coding/neteq/delay_manager.h"

 #include <math.h>

 #include "modules/audio_coding/neteq/mock/mock_delay_peak_detector.h"
 #include "test/field_trial.h"
 #include "test/gmock.h"
 #include "test/gtest.h"

 namespace webrtc {

 using ::testing::Return;
 using ::testing::_;

 class DelayManagerTest : public ::testing::Test {
  protected:
   static const int kMaxNumberOfPackets = 240;
   static const int kMinDelayMs = 0;
   static const int kTimeStepMs = 10;
   static const int kFs = 8000;
   static const int kFrameSizeMs = 20;
   static const int kTsIncrement = kFrameSizeMs * kFs / 1000;

   DelayManagerTest();
   virtual void SetUp();
   virtual void TearDown();
   void RecreateDelayManager();
   void SetPacketAudioLength(int lengt_ms);
   void InsertNextPacket();
   void IncreaseTime(int inc_ms);

   std::unique_ptr<DelayManager> dm_;
   TickTimer tick_timer_;
   MockDelayPeakDetector detector_;
   uint16_t seq_no_;
   uint32_t ts_;
 };

 DelayManagerTest::DelayManagerTest()
     : dm_(nullptr), detector_(&tick_timer_), seq_no_(0x1234), ts_(0x12345678) {}

 void DelayManagerTest::SetUp() {
   RecreateDelayManager();
 }

 void DelayManagerTest::RecreateDelayManager() {
   EXPECT_CALL(detector_, Reset()).Times(1);
   dm_.reset(new DelayManager(kMaxNumberOfPackets, kMinDelayMs, &detector_,
                              &tick_timer_));
 }

 void DelayManagerTest::SetPacketAudioLength(int lengt_ms) {
   EXPECT_CALL(detector_, SetPacketAudioLength(lengt_ms));
   dm_->SetPacketAudioLength(lengt_ms);
 }

 void DelayManagerTest::InsertNextPacket() {
   EXPECT_EQ(0, dm_->Update(seq_no_, ts_, kFs));
   seq_no_ += 1;
   ts_ += kTsIncrement;
 }

 void DelayManagerTest::IncreaseTime(int inc_ms) {
   for (int t = 0; t < inc_ms; t += kTimeStepMs) {
     tick_timer_.Increment();
   }
 }
 void DelayManagerTest::TearDown() {
   EXPECT_CALL(detector_, Die());
 }

 TEST_F(DelayManagerTest, CreateAndDestroy) {
   // Nothing to do here. The test fixture creates and destroys the DelayManager
   // object.
 }

 TEST_F(DelayManagerTest, VectorInitialization) {
   const DelayManager::IATVector& vec = dm_->iat_vector();
   double sum = 0.0;
   for (size_t i = 0; i < vec.size(); i++) {
     EXPECT_NEAR(ldexp(pow(0.5, static_cast<int>(i + 1)), 30), vec[i], 65537);
     // Tolerance 65537 in Q30 corresponds to a delta of approximately 0.00006.
     sum += vec[i];
   }
   EXPECT_EQ(1 << 30, static_cast<int>(sum));  // Should be 1 in Q30.
 }

 TEST_F(DelayManagerTest, SetPacketAudioLength) {
   const int kLengthMs = 30;
   // Expect DelayManager to pass on the new length to the detector object.
   EXPECT_CALL(detector_, SetPacketAudioLength(kLengthMs)).Times(1);
   EXPECT_EQ(0, dm_->SetPacketAudioLength(kLengthMs));
   EXPECT_EQ(-1, dm_->SetPacketAudioLength(-1));  // Illegal parameter value.
 }

 TEST_F(DelayManagerTest, PeakFound) {
   // Expect DelayManager to pass on the question to the detector.
   // Call twice, and let the detector return true the first time and false the
   // second time.
   EXPECT_CALL(detector_, peak_found())
       .WillOnce(Return(true))
       .WillOnce(Return(false));
   EXPECT_TRUE(dm_->PeakFound());
   EXPECT_FALSE(dm_->PeakFound());
 }

 TEST_F(DelayManagerTest, UpdateNormal) {
   SetPacketAudioLength(kFrameSizeMs);
   // First packet arrival.
   InsertNextPacket();
   // Advance time by one frame size.
   IncreaseTime(kFrameSizeMs);
   // Second packet arrival.
   // Expect detector update method to be called once with inter-arrival time
   // equal to 1 packet, and (base) target level equal to 1 as well.
   // Return false to indicate no peaks found.
   EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(false));
   InsertNextPacket();
   EXPECT_EQ(1 << 8, dm_->TargetLevel());  // In Q8.
   EXPECT_EQ(1, dm_->base_target_level());
   int lower, higher;
   dm_->BufferLimits(&lower, &higher);
   // Expect |lower| to be 75% of target level, and |higher| to be target level,
   // but also at least 20 ms higher than |lower|, which is the limiting case
   // here.
   EXPECT_EQ((1 << 8) * 3 / 4, lower);
   EXPECT_EQ(lower + (20 << 8) / kFrameSizeMs, higher);
 }

 TEST_F(DelayManagerTest, UpdateLongInterArrivalTime) {
   SetPacketAudioLength(kFrameSizeMs);
   // First packet arrival.
   InsertNextPacket();
   // Advance time by two frame size.
   IncreaseTime(2 * kFrameSizeMs);
   // Second packet arrival.
   // Expect detector update method to be called once with inter-arrival time
   // equal to 1 packet, and (base) target level equal to 1 as well.
   // Return false to indicate no peaks found.
   EXPECT_CALL(detector_, Update(2, 2)).WillOnce(Return(false));
   InsertNextPacket();
   EXPECT_EQ(2 << 8, dm_->TargetLevel());  // In Q8.
   EXPECT_EQ(2, dm_->base_target_level());
   int lower, higher;
   dm_->BufferLimits(&lower, &higher);
   // Expect |lower| to be 75% of target level, and |higher| to be target level,
   // but also at least 20 ms higher than |lower|, which is the limiting case
   // here.
   EXPECT_EQ((2 << 8) * 3 / 4, lower);
   EXPECT_EQ(lower + (20 << 8) / kFrameSizeMs, higher);
 }

 TEST_F(DelayManagerTest, UpdatePeakFound) {
   SetPacketAudioLength(kFrameSizeMs);
   // First packet arrival.
   InsertNextPacket();
   // Advance time by one frame size.
   IncreaseTime(kFrameSizeMs);
   // Second packet arrival.
   // Expect detector update method to be called once with inter-arrival time
   // equal to 1 packet, and (base) target level equal to 1 as well.
   // Return true to indicate that peaks are found. Let the peak height be 5.
   EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(true));
   EXPECT_CALL(detector_, MaxPeakHeight()).WillOnce(Return(5));
   InsertNextPacket();
   EXPECT_EQ(5 << 8, dm_->TargetLevel());
   EXPECT_EQ(1, dm_->base_target_level());  // Base target level is w/o peaks.
   int lower, higher;
   dm_->BufferLimits(&lower, &higher);
   // Expect |lower| to be 75% of target level, and |higher| to be target level.
   EXPECT_EQ((5 << 8) * 3 / 4, lower);
   EXPECT_EQ(5 << 8, higher);
 }

 TEST_F(DelayManagerTest, TargetDelay) {
   SetPacketAudioLength(kFrameSizeMs);
   // First packet arrival.
   InsertNextPacket();
   // Advance time by one frame size.
   IncreaseTime(kFrameSizeMs);
   // Second packet arrival.
   // Expect detector update method to be called once with inter-arrival time
   // equal to 1 packet, and (base) target level equal to 1 as well.
   // Return false to indicate no peaks found.
   EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(false));
   InsertNextPacket();
   const int kExpectedTarget = 1;
   EXPECT_EQ(kExpectedTarget << 8, dm_->TargetLevel());  // In Q8.
   EXPECT_EQ(1, dm_->base_target_level());
   int lower, higher;
   dm_->BufferLimits(&lower, &higher);
   // Expect |lower| to be 75% of base target level, and |higher| to be
   // lower + 20 ms headroom.
   EXPECT_EQ((1 << 8) * 3 / 4, lower);
   EXPECT_EQ(lower + (20 << 8) / kFrameSizeMs, higher);
 }

 TEST_F(DelayManagerTest, MaxDelay) {
   const int kExpectedTarget = 5;
   const int kTimeIncrement = kExpectedTarget * kFrameSizeMs;
   SetPacketAudioLength(kFrameSizeMs);
   // First packet arrival.
   InsertNextPacket();
   // Second packet arrival.
   // Expect detector update method to be called once with inter-arrival time
   // equal to |kExpectedTarget| packet. Return true to indicate peaks found.
   EXPECT_CALL(detector_, Update(kExpectedTarget, _))
       .WillRepeatedly(Return(true));
   EXPECT_CALL(detector_, MaxPeakHeight())
       .WillRepeatedly(Return(kExpectedTarget));
   IncreaseTime(kTimeIncrement);
   InsertNextPacket();

   // No limit is set.
   EXPECT_EQ(kExpectedTarget << 8, dm_->TargetLevel());

   int kMaxDelayPackets = kExpectedTarget - 2;
   int kMaxDelayMs = kMaxDelayPackets * kFrameSizeMs;
   EXPECT_TRUE(dm_->SetMaximumDelay(kMaxDelayMs));
   IncreaseTime(kTimeIncrement);
   InsertNextPacket();
   EXPECT_EQ(kMaxDelayPackets << 8, dm_->TargetLevel());

   // Target level at least should be one packet.
   EXPECT_FALSE(dm_->SetMaximumDelay(kFrameSizeMs - 1));
 }

 TEST_F(DelayManagerTest, MinDelay) {
   const int kExpectedTarget = 5;
   const int kTimeIncrement = kExpectedTarget * kFrameSizeMs;
   SetPacketAudioLength(kFrameSizeMs);
   // First packet arrival.
   InsertNextPacket();
   // Second packet arrival.
   // Expect detector update method to be called once with inter-arrival time
   // equal to |kExpectedTarget| packet. Return true to indicate peaks found.
   EXPECT_CALL(detector_, Update(kExpectedTarget, _))
       .WillRepeatedly(Return(true));
   EXPECT_CALL(detector_, MaxPeakHeight())
       .WillRepeatedly(Return(kExpectedTarget));
   IncreaseTime(kTimeIncrement);
   InsertNextPacket();

   // No limit is applied.
   EXPECT_EQ(kExpectedTarget << 8, dm_->TargetLevel());

   int kMinDelayPackets = kExpectedTarget + 2;
   int kMinDelayMs = kMinDelayPackets * kFrameSizeMs;
   dm_->SetMinimumDelay(kMinDelayMs);
   IncreaseTime(kTimeIncrement);
   InsertNextPacket();
   EXPECT_EQ(kMinDelayPackets << 8, dm_->TargetLevel());
 }

 // Tests that skipped sequence numbers (simulating empty packets) are handled
 // correctly.
 TEST_F(DelayManagerTest, EmptyPacketsReported) {
   SetPacketAudioLength(kFrameSizeMs);
   // First packet arrival.
   InsertNextPacket();

   // Advance time by one frame size.
   IncreaseTime(kFrameSizeMs);

   // Advance the sequence number by 5, simulating that 5 empty packets were
   // received, but never inserted.
   seq_no_ += 10;
   for (int j = 0; j < 10; ++j) {
     dm_->RegisterEmptyPacket();
   }

   // Second packet arrival.
   // Expect detector update method to be called once with inter-arrival time
   // equal to 1 packet, and (base) target level equal to 1 as well.
   // Return false to indicate no peaks found.
   EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(false));
   InsertNextPacket();

   EXPECT_EQ(1 << 8, dm_->TargetLevel());  // In Q8.
 }

 // Same as above, but do not call RegisterEmptyPacket. Observe the target level
 // increase dramatically.
 TEST_F(DelayManagerTest, EmptyPacketsNotReported) {
   SetPacketAudioLength(kFrameSizeMs);
   // First packet arrival.
   InsertNextPacket();

   // Advance time by one frame size.
   IncreaseTime(kFrameSizeMs);

   // Advance the sequence number by 5, simulating that 5 empty packets were
   // received, but never inserted.
   seq_no_ += 10;

   // Second packet arrival.
   // Expect detector update method to be called once with inter-arrival time
   // equal to 1 packet, and (base) target level equal to 1 as well.
   // Return false to indicate no peaks found.
   EXPECT_CALL(detector_, Update(10, 10)).WillOnce(Return(false));
   InsertNextPacket();

   // Note 10 times higher target value.
   EXPECT_EQ(10 * 1 << 8, dm_->TargetLevel());  // In Q8.
 }

 TEST_F(DelayManagerTest, Failures) {
   // Wrong sample rate.
   EXPECT_EQ(-1, dm_->Update(0, 0, -1));
   // Wrong packet size.
   EXPECT_EQ(-1, dm_->SetPacketAudioLength(0));
   EXPECT_EQ(-1, dm_->SetPacketAudioLength(-1));

   // Minimum delay higher than a maximum delay is not accepted.
   EXPECT_TRUE(dm_->SetMaximumDelay(10));
   EXPECT_FALSE(dm_->SetMinimumDelay(20));

   // Maximum delay less than minimum delay is not accepted.
   EXPECT_TRUE(dm_->SetMaximumDelay(100));
   EXPECT_TRUE(dm_->SetMinimumDelay(80));
   EXPECT_FALSE(dm_->SetMaximumDelay(60));
 }

 TEST_F(DelayManagerTest, TargetDelayGreaterThanOne) {
   test::ScopedFieldTrials field_trial(
       "WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled-0/");
   RecreateDelayManager();
   EXPECT_EQ(absl::make_optional<int>(1 << 30),
             dm_->forced_limit_probability_for_test());

   SetPacketAudioLength(kFrameSizeMs);
   // First packet arrival.
   InsertNextPacket();
   // Advance time by one frame size.
   IncreaseTime(kFrameSizeMs);
   // Second packet arrival.
   // Expect detector update method to be called once with inter-arrival time
   // equal to 1 packet.
   EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(false));
   InsertNextPacket();
   constexpr int kExpectedTarget = 1;
   EXPECT_EQ(kExpectedTarget << 8, dm_->TargetLevel());  // In Q8.
 }

 TEST_F(DelayManagerTest, ForcedTargetDelayPercentile) {
   {
     test::ScopedFieldTrials field_trial(
         "WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled-95/");
     RecreateDelayManager();
     EXPECT_EQ(absl::make_optional<int>(53687091),
               dm_->forced_limit_probability_for_test());  // 1/20 in Q30
   }
   {
     test::ScopedFieldTrials field_trial(
         "WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled-99.95/");
     RecreateDelayManager();
     EXPECT_EQ(absl::make_optional<int>(536871),
               dm_->forced_limit_probability_for_test());  // 1/2000 in Q30
   }
   {
     test::ScopedFieldTrials field_trial(
         "WebRTC-Audio-NetEqForceTargetDelayPercentile/Disabled/");
     RecreateDelayManager();
     EXPECT_EQ(absl::nullopt, dm_->forced_limit_probability_for_test());
   }
   {
     test::ScopedFieldTrials field_trial(
         "WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled--1/");
     EXPECT_EQ(absl::nullopt, dm_->forced_limit_probability_for_test());
   }
   {
     test::ScopedFieldTrials field_trial(
         "WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled-100.1/");
     RecreateDelayManager();
     EXPECT_EQ(absl::nullopt, dm_->forced_limit_probability_for_test());
   }
 }

 // Test if the histogram is stretched correctly if the packet size is decreased.
 TEST(DelayManagerIATScalingTest, StretchTest) {
   using IATVector = DelayManager::IATVector;
   // Test a straightforward 60ms to 20ms change.
   IATVector iat = {12, 0, 0, 0, 0, 0};
   IATVector expected_result = {4, 4, 4, 0, 0, 0};
   IATVector stretched_iat = DelayManager::ScaleHistogram(iat, 60, 20);
   EXPECT_EQ(stretched_iat, expected_result);

   // Test an example where the last bin in the stretched histogram should
   // contain the sum of the elements that don't fit into the new histogram.
   iat = {18, 15, 12, 9, 6, 3, 0};
   expected_result = {6, 6, 6, 5, 5, 5, 30};
   stretched_iat = DelayManager::ScaleHistogram(iat, 60, 20);
   EXPECT_EQ(stretched_iat, expected_result);

   // Test a 120ms to 60ms change.
   iat = {18, 16, 14, 4, 0};
   expected_result = {9, 9, 8, 8, 18};
   stretched_iat = DelayManager::ScaleHistogram(iat, 120, 60);
   EXPECT_EQ(stretched_iat, expected_result);

   // Test a 120ms to 20ms change.
   iat = {19, 12, 0, 0, 0, 0, 0, 0};
   expected_result = {3, 3, 3, 3, 3, 3, 2, 11};
   stretched_iat = DelayManager::ScaleHistogram(iat, 120, 20);
   EXPECT_EQ(stretched_iat, expected_result);

   // Test a 70ms to 40ms change.
   iat = {13, 7, 5, 3, 1, 5, 12, 11, 3, 0, 0, 0};
   expected_result = {7, 5, 5, 3, 3, 2, 2, 1, 2, 2, 6, 22};
   stretched_iat = DelayManager::ScaleHistogram(iat, 70, 40);
   EXPECT_EQ(stretched_iat, expected_result);

   // Test a 30ms to 20ms change.
   iat = {13, 7, 5, 3, 1, 5, 12, 11, 3, 0, 0, 0};
   expected_result = {8, 6, 6, 3, 2, 2, 1, 3, 3, 8, 7, 11};
   stretched_iat = DelayManager::ScaleHistogram(iat, 30, 20);
   EXPECT_EQ(stretched_iat, expected_result);
 }

 // Test if the histogram is compressed correctly if the packet size is
 // increased.
 TEST(DelayManagerIATScalingTest, CompressionTest) {
   using IATVector = DelayManager::IATVector;
   // Test a 20 to 60 ms change.
   IATVector iat = {12, 11, 10, 3, 2, 1};
   IATVector expected_result = {33, 6, 0, 0, 0, 0};
   IATVector compressed_iat = DelayManager::ScaleHistogram(iat, 20, 60);
   EXPECT_EQ(compressed_iat, expected_result);

   // Test a 60ms to 120ms change.
   iat = {18, 16, 14, 4, 1};
   expected_result = {34, 18, 1, 0, 0};
   compressed_iat = DelayManager::ScaleHistogram(iat, 60, 120);
   EXPECT_EQ(compressed_iat, expected_result);

   // Test a 20ms to 120ms change.
   iat = {18, 12, 5, 4, 4, 3, 5, 1};
   expected_result = {46, 6, 0, 0, 0, 0, 0, 0};
   compressed_iat = DelayManager::ScaleHistogram(iat, 20, 120);
   EXPECT_EQ(compressed_iat, expected_result);

   // Test a 70ms to 80ms change.
   iat = {13, 7, 5, 3, 1, 5, 12, 11, 3};
   expected_result = {11, 8, 6, 2, 5, 12, 13, 3, 0};
   compressed_iat = DelayManager::ScaleHistogram(iat, 70, 80);
   EXPECT_EQ(compressed_iat, expected_result);

   // Test a 50ms to 110ms change.
   iat = {13, 7, 5, 3, 1, 5, 12, 11, 3};
   expected_result = {18, 8, 16, 16, 2, 0, 0, 0, 0};
   compressed_iat = DelayManager::ScaleHistogram(iat, 50, 110);
   EXPECT_EQ(compressed_iat, expected_result);
 }

 // Test if the histogram scaling function handles overflows correctly.
 TEST(DelayManagerIATScalingTest, OverflowTest) {
   using IATVector = DelayManager::IATVector;
   // Test a compression operation that can cause overflow.
   IATVector iat = {733544448, 0, 0, 0, 0, 0, 0, 340197376, 0, 0, 0, 0, 0, 0};
   IATVector expected_result = {733544448, 340197376, 0, 0, 0, 0, 0,
                                0,         0,         0, 0, 0, 0, 0};
   IATVector scaled_iat = DelayManager::ScaleHistogram(iat, 10, 60);
   EXPECT_EQ(scaled_iat, expected_result);

   iat = {655591163, 39962288, 360736736, 1930514, 4003853, 1782764,
          114119,    2072996,  0,         2149354, 0};
   expected_result = {1056290187, 7717131, 2187115, 2149354, 0, 0,
                      0,          0,       0,       0,       0};
   scaled_iat = DelayManager::ScaleHistogram(iat, 20, 60);
   EXPECT_EQ(scaled_iat, expected_result);

   // In this test case we will not be able to add everything to the final bin in
   // the scaled histogram. Check that the last bin doesn't overflow.
   iat = {2000000000, 2000000000, 2000000000,
          2000000000, 2000000000, 2000000000};
   expected_result = {666666666, 666666666, 666666666,
                      666666667, 666666667, 2147483647};
   scaled_iat = DelayManager::ScaleHistogram(iat, 60, 20);
   EXPECT_EQ(scaled_iat, expected_result);

   // In this test case we will not be able to add enough to each of the bins,
   // so the values should be smeared out past the end of the normal range.
   iat = {2000000000, 2000000000, 2000000000,
          2000000000, 2000000000, 2000000000};
   expected_result = {2147483647, 2147483647, 2147483647,
                      2147483647, 2147483647, 1262581765};
   scaled_iat = DelayManager::ScaleHistogram(iat, 20, 60);
   EXPECT_EQ(scaled_iat, expected_result);
 }

 }  // namespace webrtc
	/*
	* Copyright (c) 2012 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.
	*/

	// Unit tests for DelayManager class.

	#include "modules/audio_coding/neteq/delay_manager.h"

	#include <math.h>

	#include "modules/audio_coding/neteq/mock/mock_delay_peak_detector.h"
	#include "test/field_trial.h"
	#include "test/gmock.h"
	#include "test/gtest.h"

	namespace webrtc {

	using ::testing::Return;
	using ::testing::_;

	class DelayManagerTest : public ::testing::Test {
	protected:
	static const int kMaxNumberOfPackets = 240;
	static const int kMinDelayMs = 0;
	static const int kTimeStepMs = 10;
	static const int kFs = 8000;
	static const int kFrameSizeMs = 20;
	static const int kTsIncrement = kFrameSizeMs * kFs / 1000;

	DelayManagerTest();
	virtual void SetUp();
	virtual void TearDown();
	void RecreateDelayManager();
	void SetPacketAudioLength(int lengt_ms);
	void InsertNextPacket();
	void IncreaseTime(int inc_ms);

	std::unique_ptr<DelayManager> dm_;
	TickTimer tick_timer_;
	MockDelayPeakDetector detector_;
	uint16_t seq_no_;
	uint32_t ts_;
	};

	DelayManagerTest::DelayManagerTest()
	: dm_(nullptr), detector_(&tick_timer_), seq_no_(0x1234), ts_(0x12345678) {}

	void DelayManagerTest::SetUp() {
	RecreateDelayManager();
	}

	void DelayManagerTest::RecreateDelayManager() {
	EXPECT_CALL(detector_, Reset()).Times(1);
	dm_.reset(new DelayManager(kMaxNumberOfPackets, kMinDelayMs, &detector_,
	&tick_timer_));
	}

	void DelayManagerTest::SetPacketAudioLength(int lengt_ms) {
	EXPECT_CALL(detector_, SetPacketAudioLength(lengt_ms));
	dm_->SetPacketAudioLength(lengt_ms);
	}

	void DelayManagerTest::InsertNextPacket() {
	EXPECT_EQ(0, dm_->Update(seq_no_, ts_, kFs));
	seq_no_ += 1;
	ts_ += kTsIncrement;
	}

	void DelayManagerTest::IncreaseTime(int inc_ms) {
	for (int t = 0; t < inc_ms; t += kTimeStepMs) {
	tick_timer_.Increment();
	}
	}
	void DelayManagerTest::TearDown() {
	EXPECT_CALL(detector_, Die());
	}

	TEST_F(DelayManagerTest, CreateAndDestroy) {
	// Nothing to do here. The test fixture creates and destroys the DelayManager
	// object.
	}

	TEST_F(DelayManagerTest, VectorInitialization) {
	const DelayManager::IATVector& vec = dm_->iat_vector();
	double sum = 0.0;
	for (size_t i = 0; i < vec.size(); i++) {
	EXPECT_NEAR(ldexp(pow(0.5, static_cast<int>(i + 1)), 30), vec[i], 65537);
	// Tolerance 65537 in Q30 corresponds to a delta of approximately 0.00006.
	sum += vec[i];
	}
	EXPECT_EQ(1 << 30, static_cast<int>(sum)); // Should be 1 in Q30.
	}

	TEST_F(DelayManagerTest, SetPacketAudioLength) {
	const int kLengthMs = 30;
	// Expect DelayManager to pass on the new length to the detector object.
	EXPECT_CALL(detector_, SetPacketAudioLength(kLengthMs)).Times(1);
	EXPECT_EQ(0, dm_->SetPacketAudioLength(kLengthMs));
	EXPECT_EQ(-1, dm_->SetPacketAudioLength(-1)); // Illegal parameter value.
	}

	TEST_F(DelayManagerTest, PeakFound) {
	// Expect DelayManager to pass on the question to the detector.
	// Call twice, and let the detector return true the first time and false the
	// second time.
	EXPECT_CALL(detector_, peak_found())
	.WillOnce(Return(true))
	.WillOnce(Return(false));
	EXPECT_TRUE(dm_->PeakFound());
	EXPECT_FALSE(dm_->PeakFound());
	}

	TEST_F(DelayManagerTest, UpdateNormal) {
	SetPacketAudioLength(kFrameSizeMs);
	// First packet arrival.
	InsertNextPacket();
	// Advance time by one frame size.
	IncreaseTime(kFrameSizeMs);
	// Second packet arrival.
	// Expect detector update method to be called once with inter-arrival time
	// equal to 1 packet, and (base) target level equal to 1 as well.
	// Return false to indicate no peaks found.
	EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(false));
	InsertNextPacket();
	EXPECT_EQ(1 << 8, dm_->TargetLevel()); // In Q8.
	EXPECT_EQ(1, dm_->base_target_level());
	int lower, higher;
	dm_->BufferLimits(&lower, &higher);
	// Expect \|lower\| to be 75% of target level, and \|higher\| to be target level,
	// but also at least 20 ms higher than \|lower\|, which is the limiting case
	// here.
	EXPECT_EQ((1 << 8) * 3 / 4, lower);
	EXPECT_EQ(lower + (20 << 8) / kFrameSizeMs, higher);
	}

	TEST_F(DelayManagerTest, UpdateLongInterArrivalTime) {
	SetPacketAudioLength(kFrameSizeMs);
	// First packet arrival.
	InsertNextPacket();
	// Advance time by two frame size.
	IncreaseTime(2 * kFrameSizeMs);
	// Second packet arrival.
	// Expect detector update method to be called once with inter-arrival time
	// equal to 1 packet, and (base) target level equal to 1 as well.
	// Return false to indicate no peaks found.
	EXPECT_CALL(detector_, Update(2, 2)).WillOnce(Return(false));
	InsertNextPacket();
	EXPECT_EQ(2 << 8, dm_->TargetLevel()); // In Q8.
	EXPECT_EQ(2, dm_->base_target_level());
	int lower, higher;
	dm_->BufferLimits(&lower, &higher);
	// Expect \|lower\| to be 75% of target level, and \|higher\| to be target level,
	// but also at least 20 ms higher than \|lower\|, which is the limiting case
	// here.
	EXPECT_EQ((2 << 8) * 3 / 4, lower);
	EXPECT_EQ(lower + (20 << 8) / kFrameSizeMs, higher);
	}

	TEST_F(DelayManagerTest, UpdatePeakFound) {
	SetPacketAudioLength(kFrameSizeMs);
	// First packet arrival.
	InsertNextPacket();
	// Advance time by one frame size.
	IncreaseTime(kFrameSizeMs);
	// Second packet arrival.
	// Expect detector update method to be called once with inter-arrival time
	// equal to 1 packet, and (base) target level equal to 1 as well.
	// Return true to indicate that peaks are found. Let the peak height be 5.
	EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(true));
	EXPECT_CALL(detector_, MaxPeakHeight()).WillOnce(Return(5));
	InsertNextPacket();
	EXPECT_EQ(5 << 8, dm_->TargetLevel());
	EXPECT_EQ(1, dm_->base_target_level()); // Base target level is w/o peaks.
	int lower, higher;
	dm_->BufferLimits(&lower, &higher);
	// Expect \|lower\| to be 75% of target level, and \|higher\| to be target level.
	EXPECT_EQ((5 << 8) * 3 / 4, lower);
	EXPECT_EQ(5 << 8, higher);
	}

	TEST_F(DelayManagerTest, TargetDelay) {
	SetPacketAudioLength(kFrameSizeMs);
	// First packet arrival.
	InsertNextPacket();
	// Advance time by one frame size.
	IncreaseTime(kFrameSizeMs);
	// Second packet arrival.
	// Expect detector update method to be called once with inter-arrival time
	// equal to 1 packet, and (base) target level equal to 1 as well.
	// Return false to indicate no peaks found.
	EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(false));
	InsertNextPacket();
	const int kExpectedTarget = 1;
	EXPECT_EQ(kExpectedTarget << 8, dm_->TargetLevel()); // In Q8.
	EXPECT_EQ(1, dm_->base_target_level());
	int lower, higher;
	dm_->BufferLimits(&lower, &higher);
	// Expect \|lower\| to be 75% of base target level, and \|higher\| to be
	// lower + 20 ms headroom.
	EXPECT_EQ((1 << 8) * 3 / 4, lower);
	EXPECT_EQ(lower + (20 << 8) / kFrameSizeMs, higher);
	}

	TEST_F(DelayManagerTest, MaxDelay) {
	const int kExpectedTarget = 5;
	const int kTimeIncrement = kExpectedTarget * kFrameSizeMs;
	SetPacketAudioLength(kFrameSizeMs);
	// First packet arrival.
	InsertNextPacket();
	// Second packet arrival.
	// Expect detector update method to be called once with inter-arrival time
	// equal to \|kExpectedTarget\| packet. Return true to indicate peaks found.
	EXPECT_CALL(detector_, Update(kExpectedTarget, _))
	.WillRepeatedly(Return(true));
	EXPECT_CALL(detector_, MaxPeakHeight())
	.WillRepeatedly(Return(kExpectedTarget));
	IncreaseTime(kTimeIncrement);
	InsertNextPacket();

	// No limit is set.
	EXPECT_EQ(kExpectedTarget << 8, dm_->TargetLevel());

	int kMaxDelayPackets = kExpectedTarget - 2;
	int kMaxDelayMs = kMaxDelayPackets * kFrameSizeMs;
	EXPECT_TRUE(dm_->SetMaximumDelay(kMaxDelayMs));
	IncreaseTime(kTimeIncrement);
	InsertNextPacket();
	EXPECT_EQ(kMaxDelayPackets << 8, dm_->TargetLevel());

	// Target level at least should be one packet.
	EXPECT_FALSE(dm_->SetMaximumDelay(kFrameSizeMs - 1));
	}

	TEST_F(DelayManagerTest, MinDelay) {
	const int kExpectedTarget = 5;
	const int kTimeIncrement = kExpectedTarget * kFrameSizeMs;
	SetPacketAudioLength(kFrameSizeMs);
	// First packet arrival.
	InsertNextPacket();
	// Second packet arrival.
	// Expect detector update method to be called once with inter-arrival time
	// equal to \|kExpectedTarget\| packet. Return true to indicate peaks found.
	EXPECT_CALL(detector_, Update(kExpectedTarget, _))
	.WillRepeatedly(Return(true));
	EXPECT_CALL(detector_, MaxPeakHeight())
	.WillRepeatedly(Return(kExpectedTarget));
	IncreaseTime(kTimeIncrement);
	InsertNextPacket();

	// No limit is applied.
	EXPECT_EQ(kExpectedTarget << 8, dm_->TargetLevel());

	int kMinDelayPackets = kExpectedTarget + 2;
	int kMinDelayMs = kMinDelayPackets * kFrameSizeMs;
	dm_->SetMinimumDelay(kMinDelayMs);
	IncreaseTime(kTimeIncrement);
	InsertNextPacket();
	EXPECT_EQ(kMinDelayPackets << 8, dm_->TargetLevel());
	}

	// Tests that skipped sequence numbers (simulating empty packets) are handled
	// correctly.
	TEST_F(DelayManagerTest, EmptyPacketsReported) {
	SetPacketAudioLength(kFrameSizeMs);
	// First packet arrival.
	InsertNextPacket();

	// Advance time by one frame size.
	IncreaseTime(kFrameSizeMs);

	// Advance the sequence number by 5, simulating that 5 empty packets were
	// received, but never inserted.
	seq_no_ += 10;
	for (int j = 0; j < 10; ++j) {
	dm_->RegisterEmptyPacket();
	}

	// Second packet arrival.
	// Expect detector update method to be called once with inter-arrival time
	// equal to 1 packet, and (base) target level equal to 1 as well.
	// Return false to indicate no peaks found.
	EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(false));
	InsertNextPacket();

	EXPECT_EQ(1 << 8, dm_->TargetLevel()); // In Q8.
	}

	// Same as above, but do not call RegisterEmptyPacket. Observe the target level
	// increase dramatically.
	TEST_F(DelayManagerTest, EmptyPacketsNotReported) {
	SetPacketAudioLength(kFrameSizeMs);
	// First packet arrival.
	InsertNextPacket();

	// Advance time by one frame size.
	IncreaseTime(kFrameSizeMs);

	// Advance the sequence number by 5, simulating that 5 empty packets were
	// received, but never inserted.
	seq_no_ += 10;

	// Second packet arrival.
	// Expect detector update method to be called once with inter-arrival time
	// equal to 1 packet, and (base) target level equal to 1 as well.
	// Return false to indicate no peaks found.
	EXPECT_CALL(detector_, Update(10, 10)).WillOnce(Return(false));
	InsertNextPacket();

	// Note 10 times higher target value.
	EXPECT_EQ(10 * 1 << 8, dm_->TargetLevel()); // In Q8.
	}

	TEST_F(DelayManagerTest, Failures) {
	// Wrong sample rate.
	EXPECT_EQ(-1, dm_->Update(0, 0, -1));
	// Wrong packet size.
	EXPECT_EQ(-1, dm_->SetPacketAudioLength(0));
	EXPECT_EQ(-1, dm_->SetPacketAudioLength(-1));

	// Minimum delay higher than a maximum delay is not accepted.
	EXPECT_TRUE(dm_->SetMaximumDelay(10));
	EXPECT_FALSE(dm_->SetMinimumDelay(20));

	// Maximum delay less than minimum delay is not accepted.
	EXPECT_TRUE(dm_->SetMaximumDelay(100));
	EXPECT_TRUE(dm_->SetMinimumDelay(80));
	EXPECT_FALSE(dm_->SetMaximumDelay(60));
	}

	TEST_F(DelayManagerTest, TargetDelayGreaterThanOne) {
	test::ScopedFieldTrials field_trial(
	"WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled-0/");
	RecreateDelayManager();
	EXPECT_EQ(absl::make_optional<int>(1 << 30),
	dm_->forced_limit_probability_for_test());

	SetPacketAudioLength(kFrameSizeMs);
	// First packet arrival.
	InsertNextPacket();
	// Advance time by one frame size.
	IncreaseTime(kFrameSizeMs);
	// Second packet arrival.
	// Expect detector update method to be called once with inter-arrival time
	// equal to 1 packet.
	EXPECT_CALL(detector_, Update(1, 1)).WillOnce(Return(false));
	InsertNextPacket();
	constexpr int kExpectedTarget = 1;
	EXPECT_EQ(kExpectedTarget << 8, dm_->TargetLevel()); // In Q8.
	}

	TEST_F(DelayManagerTest, ForcedTargetDelayPercentile) {
	{
	test::ScopedFieldTrials field_trial(
	"WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled-95/");
	RecreateDelayManager();
	EXPECT_EQ(absl::make_optional<int>(53687091),
	dm_->forced_limit_probability_for_test()); // 1/20 in Q30
	}
	{
	test::ScopedFieldTrials field_trial(
	"WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled-99.95/");
	RecreateDelayManager();
	EXPECT_EQ(absl::make_optional<int>(536871),
	dm_->forced_limit_probability_for_test()); // 1/2000 in Q30
	}
	{
	test::ScopedFieldTrials field_trial(
	"WebRTC-Audio-NetEqForceTargetDelayPercentile/Disabled/");
	RecreateDelayManager();
	EXPECT_EQ(absl::nullopt, dm_->forced_limit_probability_for_test());
	}
	{
	test::ScopedFieldTrials field_trial(
	"WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled--1/");
	EXPECT_EQ(absl::nullopt, dm_->forced_limit_probability_for_test());
	}
	{
	test::ScopedFieldTrials field_trial(
	"WebRTC-Audio-NetEqForceTargetDelayPercentile/Enabled-100.1/");
	RecreateDelayManager();
	EXPECT_EQ(absl::nullopt, dm_->forced_limit_probability_for_test());
	}
	}

	// Test if the histogram is stretched correctly if the packet size is decreased.
	TEST(DelayManagerIATScalingTest, StretchTest) {
	using IATVector = DelayManager::IATVector;
	// Test a straightforward 60ms to 20ms change.
	IATVector iat = {12, 0, 0, 0, 0, 0};
	IATVector expected_result = {4, 4, 4, 0, 0, 0};
	IATVector stretched_iat = DelayManager::ScaleHistogram(iat, 60, 20);
	EXPECT_EQ(stretched_iat, expected_result);

	// Test an example where the last bin in the stretched histogram should
	// contain the sum of the elements that don't fit into the new histogram.
	iat = {18, 15, 12, 9, 6, 3, 0};
	expected_result = {6, 6, 6, 5, 5, 5, 30};
	stretched_iat = DelayManager::ScaleHistogram(iat, 60, 20);
	EXPECT_EQ(stretched_iat, expected_result);

	// Test a 120ms to 60ms change.
	iat = {18, 16, 14, 4, 0};
	expected_result = {9, 9, 8, 8, 18};
	stretched_iat = DelayManager::ScaleHistogram(iat, 120, 60);
	EXPECT_EQ(stretched_iat, expected_result);

	// Test a 120ms to 20ms change.
	iat = {19, 12, 0, 0, 0, 0, 0, 0};
	expected_result = {3, 3, 3, 3, 3, 3, 2, 11};
	stretched_iat = DelayManager::ScaleHistogram(iat, 120, 20);
	EXPECT_EQ(stretched_iat, expected_result);

	// Test a 70ms to 40ms change.
	iat = {13, 7, 5, 3, 1, 5, 12, 11, 3, 0, 0, 0};
	expected_result = {7, 5, 5, 3, 3, 2, 2, 1, 2, 2, 6, 22};
	stretched_iat = DelayManager::ScaleHistogram(iat, 70, 40);
	EXPECT_EQ(stretched_iat, expected_result);

	// Test a 30ms to 20ms change.
	iat = {13, 7, 5, 3, 1, 5, 12, 11, 3, 0, 0, 0};
	expected_result = {8, 6, 6, 3, 2, 2, 1, 3, 3, 8, 7, 11};
	stretched_iat = DelayManager::ScaleHistogram(iat, 30, 20);
	EXPECT_EQ(stretched_iat, expected_result);
	}

	// Test if the histogram is compressed correctly if the packet size is
	// increased.
	TEST(DelayManagerIATScalingTest, CompressionTest) {
	using IATVector = DelayManager::IATVector;
	// Test a 20 to 60 ms change.
	IATVector iat = {12, 11, 10, 3, 2, 1};
	IATVector expected_result = {33, 6, 0, 0, 0, 0};
	IATVector compressed_iat = DelayManager::ScaleHistogram(iat, 20, 60);
	EXPECT_EQ(compressed_iat, expected_result);

	// Test a 60ms to 120ms change.
	iat = {18, 16, 14, 4, 1};
	expected_result = {34, 18, 1, 0, 0};
	compressed_iat = DelayManager::ScaleHistogram(iat, 60, 120);
	EXPECT_EQ(compressed_iat, expected_result);

	// Test a 20ms to 120ms change.
	iat = {18, 12, 5, 4, 4, 3, 5, 1};
	expected_result = {46, 6, 0, 0, 0, 0, 0, 0};
	compressed_iat = DelayManager::ScaleHistogram(iat, 20, 120);
	EXPECT_EQ(compressed_iat, expected_result);

	// Test a 70ms to 80ms change.
	iat = {13, 7, 5, 3, 1, 5, 12, 11, 3};
	expected_result = {11, 8, 6, 2, 5, 12, 13, 3, 0};
	compressed_iat = DelayManager::ScaleHistogram(iat, 70, 80);
	EXPECT_EQ(compressed_iat, expected_result);

	// Test a 50ms to 110ms change.
	iat = {13, 7, 5, 3, 1, 5, 12, 11, 3};
	expected_result = {18, 8, 16, 16, 2, 0, 0, 0, 0};
	compressed_iat = DelayManager::ScaleHistogram(iat, 50, 110);
	EXPECT_EQ(compressed_iat, expected_result);
	}

	// Test if the histogram scaling function handles overflows correctly.
	TEST(DelayManagerIATScalingTest, OverflowTest) {
	using IATVector = DelayManager::IATVector;
	// Test a compression operation that can cause overflow.
	IATVector iat = {733544448, 0, 0, 0, 0, 0, 0, 340197376, 0, 0, 0, 0, 0, 0};
	IATVector expected_result = {733544448, 340197376, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0};
	IATVector scaled_iat = DelayManager::ScaleHistogram(iat, 10, 60);
	EXPECT_EQ(scaled_iat, expected_result);

	iat = {655591163, 39962288, 360736736, 1930514, 4003853, 1782764,
	114119, 2072996, 0, 2149354, 0};
	expected_result = {1056290187, 7717131, 2187115, 2149354, 0, 0,
	0, 0, 0, 0, 0};
	scaled_iat = DelayManager::ScaleHistogram(iat, 20, 60);
	EXPECT_EQ(scaled_iat, expected_result);

	// In this test case we will not be able to add everything to the final bin in
	// the scaled histogram. Check that the last bin doesn't overflow.
	iat = {2000000000, 2000000000, 2000000000,
	2000000000, 2000000000, 2000000000};
	expected_result = {666666666, 666666666, 666666666,
	666666667, 666666667, 2147483647};
	scaled_iat = DelayManager::ScaleHistogram(iat, 60, 20);
	EXPECT_EQ(scaled_iat, expected_result);

	// In this test case we will not be able to add enough to each of the bins,
	// so the values should be smeared out past the end of the normal range.
	iat = {2000000000, 2000000000, 2000000000,
	2000000000, 2000000000, 2000000000};
	expected_result = {2147483647, 2147483647, 2147483647,
	2147483647, 2147483647, 1262581765};
	scaled_iat = DelayManager::ScaleHistogram(iat, 20, 60);
	EXPECT_EQ(scaled_iat, expected_result);
	}

	} // namespace webrtc