modules/congestion_controller/transport_feedback_adapter_unittest.cc - src - Git at Google

 /*
  *  Copyright (c) 2015 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 <limits>
 #include <memory>
 #include <vector>

 #include "modules/bitrate_controller/include/mock/mock_bitrate_controller.h"
 #include "modules/congestion_controller/rtp/congestion_controller_unittests_helper.h"
 #include "modules/congestion_controller/transport_feedback_adapter.h"
 #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/numerics/safe_conversions.h"
 #include "system_wrappers/include/clock.h"
 #include "test/gmock.h"
 #include "test/gtest.h"

 using ::testing::_;
 using ::testing::Invoke;

 namespace webrtc {

 namespace {
 const PacedPacketInfo kPacingInfo0(0, 5, 2000);
 const PacedPacketInfo kPacingInfo1(1, 8, 4000);
 const PacedPacketInfo kPacingInfo2(2, 14, 7000);
 const PacedPacketInfo kPacingInfo3(3, 20, 10000);
 const PacedPacketInfo kPacingInfo4(4, 22, 10000);
 }

 namespace test {

 class MockPacketFeedbackObserver : public webrtc::PacketFeedbackObserver {
  public:
   MOCK_METHOD2(OnPacketAdded, void(uint32_t ssrc, uint16_t seq_num));
   MOCK_METHOD1(OnPacketFeedbackVector,
                void(const std::vector<PacketFeedback>& packet_feedback_vector));
 };

 class LegacyTransportFeedbackAdapterTest : public ::testing::Test {
  public:
   LegacyTransportFeedbackAdapterTest() : clock_(0) {}

   virtual ~LegacyTransportFeedbackAdapterTest() {}

   virtual void SetUp() {
     adapter_.reset(new TransportFeedbackAdapter(&clock_));
   }

   virtual void TearDown() { adapter_.reset(); }

  protected:
   void OnReceivedEstimatedBitrate(uint32_t bitrate) {}

   void OnReceivedRtcpReceiverReport(const ReportBlockList& report_blocks,
                                     int64_t rtt,
                                     int64_t now_ms) {}

   void OnSentPacket(const PacketFeedback& packet_feedback) {
     adapter_->AddPacket(kSsrc, packet_feedback.sequence_number,
                         packet_feedback.payload_size,
                         packet_feedback.pacing_info);
     adapter_->OnSentPacket(packet_feedback.sequence_number,
                            packet_feedback.send_time_ms);
   }

   static constexpr uint32_t kSsrc = 8492;

   SimulatedClock clock_;
   std::unique_ptr<TransportFeedbackAdapter> adapter_;
 };

 TEST_F(LegacyTransportFeedbackAdapterTest, ObserverSanity) {
   MockPacketFeedbackObserver mock;
   adapter_->RegisterPacketFeedbackObserver(&mock);

   const std::vector<PacketFeedback> packets = {
       PacketFeedback(100, 200, 0, 1000, kPacingInfo0),
       PacketFeedback(110, 210, 1, 2000, kPacingInfo0),
       PacketFeedback(120, 220, 2, 3000, kPacingInfo0)
   };

   rtcp::TransportFeedback feedback;
   feedback.SetBase(packets[0].sequence_number,
                    packets[0].arrival_time_ms * 1000);

   for (const PacketFeedback& packet : packets) {
     EXPECT_CALL(mock, OnPacketAdded(kSsrc, packet.sequence_number)).Times(1);
     OnSentPacket(packet);
     EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
                                            packet.arrival_time_ms * 1000));
   }

   EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(1);
   adapter_->OnTransportFeedback(feedback);

   adapter_->DeRegisterPacketFeedbackObserver(&mock);

   // After deregistration, the observer no longers gets indications.
   EXPECT_CALL(mock, OnPacketAdded(_, _)).Times(0);
   const PacketFeedback new_packet(130, 230, 3, 4000, kPacingInfo0);
   OnSentPacket(new_packet);

   rtcp::TransportFeedback second_feedback;
   second_feedback.SetBase(new_packet.sequence_number,
                           new_packet.arrival_time_ms * 1000);
   EXPECT_TRUE(feedback.AddReceivedPacket(new_packet.sequence_number,
                                          new_packet.arrival_time_ms * 1000));
   EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(0);
   adapter_->OnTransportFeedback(second_feedback);
 }

 #if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
 TEST_F(LegacyTransportFeedbackAdapterTest,
        ObserverDoubleRegistrationDeathTest) {
   MockPacketFeedbackObserver mock;
   adapter_->RegisterPacketFeedbackObserver(&mock);
   EXPECT_DEATH(adapter_->RegisterPacketFeedbackObserver(&mock), "");
   adapter_->DeRegisterPacketFeedbackObserver(&mock);
 }

 TEST_F(LegacyTransportFeedbackAdapterTest,
        ObserverMissingDeRegistrationDeathTest) {
   MockPacketFeedbackObserver mock;
   adapter_->RegisterPacketFeedbackObserver(&mock);
   EXPECT_DEATH(adapter_.reset(), "");
   adapter_->DeRegisterPacketFeedbackObserver(&mock);
 }
 #endif

 TEST_F(LegacyTransportFeedbackAdapterTest,
        AdaptsFeedbackAndPopulatesSendTimes) {
   std::vector<PacketFeedback> packets;
   packets.push_back(PacketFeedback(100, 200, 0, 1500, kPacingInfo0));
   packets.push_back(PacketFeedback(110, 210, 1, 1500, kPacingInfo0));
   packets.push_back(PacketFeedback(120, 220, 2, 1500, kPacingInfo0));
   packets.push_back(PacketFeedback(130, 230, 3, 1500, kPacingInfo1));
   packets.push_back(PacketFeedback(140, 240, 4, 1500, kPacingInfo1));

   for (const PacketFeedback& packet : packets)
     OnSentPacket(packet);

   rtcp::TransportFeedback feedback;
   feedback.SetBase(packets[0].sequence_number,
                    packets[0].arrival_time_ms * 1000);

   for (const PacketFeedback& packet : packets) {
     EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
                                            packet.arrival_time_ms * 1000));
   }

   feedback.Build();

   adapter_->OnTransportFeedback(feedback);
   ComparePacketFeedbackVectors(packets, adapter_->GetTransportFeedbackVector());
 }

 TEST_F(LegacyTransportFeedbackAdapterTest, FeedbackVectorReportsUnreceived) {
   std::vector<PacketFeedback> sent_packets = {
       PacketFeedback(100, 220, 0, 1500, kPacingInfo0),
       PacketFeedback(110, 210, 1, 1500, kPacingInfo0),
       PacketFeedback(120, 220, 2, 1500, kPacingInfo0),
       PacketFeedback(130, 230, 3, 1500, kPacingInfo0),
       PacketFeedback(140, 240, 4, 1500, kPacingInfo0),
       PacketFeedback(150, 250, 5, 1500, kPacingInfo0),
       PacketFeedback(160, 260, 6, 1500, kPacingInfo0)
   };

   for (const PacketFeedback& packet : sent_packets)
     OnSentPacket(packet);

   // Note: Important to include the last packet, as only unreceived packets in
   // between received packets can be inferred.
   std::vector<PacketFeedback> received_packets = {
     sent_packets[0], sent_packets[2], sent_packets[6]
   };

   rtcp::TransportFeedback feedback;
   feedback.SetBase(received_packets[0].sequence_number,
                    received_packets[0].arrival_time_ms * 1000);

   for (const PacketFeedback& packet : received_packets) {
     EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
                                            packet.arrival_time_ms * 1000));
   }

   feedback.Build();

   adapter_->OnTransportFeedback(feedback);
   ComparePacketFeedbackVectors(sent_packets,
                                adapter_->GetTransportFeedbackVector());
 }

 TEST_F(LegacyTransportFeedbackAdapterTest, HandlesDroppedPackets) {
   std::vector<PacketFeedback> packets;
   packets.push_back(PacketFeedback(100, 200, 0, 1500, kPacingInfo0));
   packets.push_back(PacketFeedback(110, 210, 1, 1500, kPacingInfo1));
   packets.push_back(PacketFeedback(120, 220, 2, 1500, kPacingInfo2));
   packets.push_back(PacketFeedback(130, 230, 3, 1500, kPacingInfo3));
   packets.push_back(PacketFeedback(140, 240, 4, 1500, kPacingInfo4));

   const uint16_t kSendSideDropBefore = 1;
   const uint16_t kReceiveSideDropAfter = 3;

   for (const PacketFeedback& packet : packets) {
     if (packet.sequence_number >= kSendSideDropBefore)
       OnSentPacket(packet);
   }

   rtcp::TransportFeedback feedback;
   feedback.SetBase(packets[0].sequence_number,
                    packets[0].arrival_time_ms * 1000);

   for (const PacketFeedback& packet : packets) {
     if (packet.sequence_number <= kReceiveSideDropAfter) {
       EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
                                              packet.arrival_time_ms * 1000));
     }
   }

   feedback.Build();

   std::vector<PacketFeedback> expected_packets(
       packets.begin(), packets.begin() + kReceiveSideDropAfter + 1);
   // Packets that have timed out on the send-side have lost the
   // information stored on the send-side.
   for (size_t i = 0; i < kSendSideDropBefore; ++i) {
     expected_packets[i].send_time_ms = -1;
     expected_packets[i].payload_size = 0;
     expected_packets[i].pacing_info = PacedPacketInfo();
   }

   adapter_->OnTransportFeedback(feedback);
   ComparePacketFeedbackVectors(expected_packets,
                                adapter_->GetTransportFeedbackVector());
 }

 TEST_F(LegacyTransportFeedbackAdapterTest, SendTimeWrapsBothWays) {
   int64_t kHighArrivalTimeMs = rtcp::TransportFeedback::kDeltaScaleFactor *
                                static_cast<int64_t>(1 << 8) *
                                static_cast<int64_t>((1 << 23) - 1) / 1000;
   std::vector<PacketFeedback> packets;
   packets.push_back(
       PacketFeedback(kHighArrivalTimeMs - 64, 200, 0, 1500, PacedPacketInfo()));
   packets.push_back(
       PacketFeedback(kHighArrivalTimeMs + 64, 210, 1, 1500, PacedPacketInfo()));
   packets.push_back(
       PacketFeedback(kHighArrivalTimeMs, 220, 2, 1500, PacedPacketInfo()));

   for (const PacketFeedback& packet : packets)
     OnSentPacket(packet);

   for (size_t i = 0; i < packets.size(); ++i) {
     std::unique_ptr<rtcp::TransportFeedback> feedback(
         new rtcp::TransportFeedback());
     feedback->SetBase(packets[i].sequence_number,
                       packets[i].arrival_time_ms * 1000);

     EXPECT_TRUE(feedback->AddReceivedPacket(packets[i].sequence_number,
                                             packets[i].arrival_time_ms * 1000));

     rtc::Buffer raw_packet = feedback->Build();
     feedback = rtcp::TransportFeedback::ParseFrom(raw_packet.data(),
                                                   raw_packet.size());

     std::vector<PacketFeedback> expected_packets;
     expected_packets.push_back(packets[i]);

     adapter_->OnTransportFeedback(*feedback.get());
     ComparePacketFeedbackVectors(expected_packets,
                                  adapter_->GetTransportFeedbackVector());
   }
 }

 TEST_F(LegacyTransportFeedbackAdapterTest, HandlesArrivalReordering) {
   std::vector<PacketFeedback> packets;
   packets.push_back(PacketFeedback(120, 200, 0, 1500, kPacingInfo0));
   packets.push_back(PacketFeedback(110, 210, 1, 1500, kPacingInfo0));
   packets.push_back(PacketFeedback(100, 220, 2, 1500, kPacingInfo0));

   for (const PacketFeedback& packet : packets)
     OnSentPacket(packet);

   rtcp::TransportFeedback feedback;
   feedback.SetBase(packets[0].sequence_number,
                    packets[0].arrival_time_ms * 1000);

   for (const PacketFeedback& packet : packets) {
     EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
                                            packet.arrival_time_ms * 1000));
   }

   feedback.Build();

   // Adapter keeps the packets ordered by sequence number (which is itself
   // assigned by the order of transmission). Reordering by some other criteria,
   // eg. arrival time, is up to the observers.
   adapter_->OnTransportFeedback(feedback);
   ComparePacketFeedbackVectors(packets, adapter_->GetTransportFeedbackVector());
 }

 TEST_F(LegacyTransportFeedbackAdapterTest, TimestampDeltas) {
   std::vector<PacketFeedback> sent_packets;
   const int64_t kSmallDeltaUs =
       rtcp::TransportFeedback::kDeltaScaleFactor * ((1 << 8) - 1);
   const int64_t kLargePositiveDeltaUs =
       rtcp::TransportFeedback::kDeltaScaleFactor *
       std::numeric_limits<int16_t>::max();
   const int64_t kLargeNegativeDeltaUs =
       rtcp::TransportFeedback::kDeltaScaleFactor *
       std::numeric_limits<int16_t>::min();

   PacketFeedback packet_feedback(100, 200, 0, 1500, true, 0, 0,
                                  PacedPacketInfo());
   sent_packets.push_back(packet_feedback);

   packet_feedback.send_time_ms += kSmallDeltaUs / 1000;
   packet_feedback.arrival_time_ms += kSmallDeltaUs / 1000;
   ++packet_feedback.sequence_number;
   sent_packets.push_back(packet_feedback);

   packet_feedback.send_time_ms += kLargePositiveDeltaUs / 1000;
   packet_feedback.arrival_time_ms += kLargePositiveDeltaUs / 1000;
   ++packet_feedback.sequence_number;
   sent_packets.push_back(packet_feedback);

   packet_feedback.send_time_ms += kLargeNegativeDeltaUs / 1000;
   packet_feedback.arrival_time_ms += kLargeNegativeDeltaUs / 1000;
   ++packet_feedback.sequence_number;
   sent_packets.push_back(packet_feedback);

   // Too large, delta - will need two feedback messages.
   packet_feedback.send_time_ms += (kLargePositiveDeltaUs + 1000) / 1000;
   packet_feedback.arrival_time_ms += (kLargePositiveDeltaUs + 1000) / 1000;
   ++packet_feedback.sequence_number;

   // Packets will be added to send history.
   for (const PacketFeedback& packet : sent_packets)
     OnSentPacket(packet);
   OnSentPacket(packet_feedback);

   // Create expected feedback and send into adapter.
   std::unique_ptr<rtcp::TransportFeedback> feedback(
       new rtcp::TransportFeedback());
   feedback->SetBase(sent_packets[0].sequence_number,
                     sent_packets[0].arrival_time_ms * 1000);

   for (const PacketFeedback& packet : sent_packets) {
     EXPECT_TRUE(feedback->AddReceivedPacket(packet.sequence_number,
                                             packet.arrival_time_ms * 1000));
   }
   EXPECT_FALSE(feedback->AddReceivedPacket(
       packet_feedback.sequence_number, packet_feedback.arrival_time_ms * 1000));

   rtc::Buffer raw_packet = feedback->Build();
   feedback =
       rtcp::TransportFeedback::ParseFrom(raw_packet.data(), raw_packet.size());

   std::vector<PacketFeedback> received_feedback;

   EXPECT_TRUE(feedback.get() != nullptr);
   adapter_->OnTransportFeedback(*feedback.get());
   ComparePacketFeedbackVectors(sent_packets,
                                adapter_->GetTransportFeedbackVector());

   // Create a new feedback message and add the trailing item.
   feedback.reset(new rtcp::TransportFeedback());
   feedback->SetBase(packet_feedback.sequence_number,
                     packet_feedback.arrival_time_ms * 1000);
   EXPECT_TRUE(feedback->AddReceivedPacket(
       packet_feedback.sequence_number, packet_feedback.arrival_time_ms * 1000));
   raw_packet = feedback->Build();
   feedback =
       rtcp::TransportFeedback::ParseFrom(raw_packet.data(), raw_packet.size());

   EXPECT_TRUE(feedback.get() != nullptr);
   adapter_->OnTransportFeedback(*feedback.get());
   {
     std::vector<PacketFeedback> expected_packets;
     expected_packets.push_back(packet_feedback);
     ComparePacketFeedbackVectors(expected_packets,
                                  adapter_->GetTransportFeedbackVector());
   }
 }
 }  // namespace test
 }  // namespace webrtc
	/*
	* Copyright (c) 2015 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 <limits>
	#include <memory>
	#include <vector>

	#include "modules/bitrate_controller/include/mock/mock_bitrate_controller.h"
	#include "modules/congestion_controller/rtp/congestion_controller_unittests_helper.h"
	#include "modules/congestion_controller/transport_feedback_adapter.h"
	#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
	#include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
	#include "rtc_base/checks.h"
	#include "rtc_base/numerics/safe_conversions.h"
	#include "system_wrappers/include/clock.h"
	#include "test/gmock.h"
	#include "test/gtest.h"

	using ::testing::_;
	using ::testing::Invoke;

	namespace webrtc {

	namespace {
	const PacedPacketInfo kPacingInfo0(0, 5, 2000);
	const PacedPacketInfo kPacingInfo1(1, 8, 4000);
	const PacedPacketInfo kPacingInfo2(2, 14, 7000);
	const PacedPacketInfo kPacingInfo3(3, 20, 10000);
	const PacedPacketInfo kPacingInfo4(4, 22, 10000);
	}

	namespace test {

	class MockPacketFeedbackObserver : public webrtc::PacketFeedbackObserver {
	public:
	MOCK_METHOD2(OnPacketAdded, void(uint32_t ssrc, uint16_t seq_num));
	MOCK_METHOD1(OnPacketFeedbackVector,
	void(const std::vector<PacketFeedback>& packet_feedback_vector));
	};

	class LegacyTransportFeedbackAdapterTest : public ::testing::Test {
	public:
	LegacyTransportFeedbackAdapterTest() : clock_(0) {}

	virtual ~LegacyTransportFeedbackAdapterTest() {}

	virtual void SetUp() {
	adapter_.reset(new TransportFeedbackAdapter(&clock_));
	}

	virtual void TearDown() { adapter_.reset(); }

	protected:
	void OnReceivedEstimatedBitrate(uint32_t bitrate) {}

	void OnReceivedRtcpReceiverReport(const ReportBlockList& report_blocks,
	int64_t rtt,
	int64_t now_ms) {}

	void OnSentPacket(const PacketFeedback& packet_feedback) {
	adapter_->AddPacket(kSsrc, packet_feedback.sequence_number,
	packet_feedback.payload_size,
	packet_feedback.pacing_info);
	adapter_->OnSentPacket(packet_feedback.sequence_number,
	packet_feedback.send_time_ms);
	}

	static constexpr uint32_t kSsrc = 8492;

	SimulatedClock clock_;
	std::unique_ptr<TransportFeedbackAdapter> adapter_;
	};

	TEST_F(LegacyTransportFeedbackAdapterTest, ObserverSanity) {
	MockPacketFeedbackObserver mock;
	adapter_->RegisterPacketFeedbackObserver(&mock);

	const std::vector<PacketFeedback> packets = {
	PacketFeedback(100, 200, 0, 1000, kPacingInfo0),
	PacketFeedback(110, 210, 1, 2000, kPacingInfo0),
	PacketFeedback(120, 220, 2, 3000, kPacingInfo0)
	};

	rtcp::TransportFeedback feedback;
	feedback.SetBase(packets[0].sequence_number,
	packets[0].arrival_time_ms * 1000);

	for (const PacketFeedback& packet : packets) {
	EXPECT_CALL(mock, OnPacketAdded(kSsrc, packet.sequence_number)).Times(1);
	OnSentPacket(packet);
	EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
	packet.arrival_time_ms * 1000));
	}

	EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(1);
	adapter_->OnTransportFeedback(feedback);

	adapter_->DeRegisterPacketFeedbackObserver(&mock);

	// After deregistration, the observer no longers gets indications.
	EXPECT_CALL(mock, OnPacketAdded(_, _)).Times(0);
	const PacketFeedback new_packet(130, 230, 3, 4000, kPacingInfo0);
	OnSentPacket(new_packet);

	rtcp::TransportFeedback second_feedback;
	second_feedback.SetBase(new_packet.sequence_number,
	new_packet.arrival_time_ms * 1000);
	EXPECT_TRUE(feedback.AddReceivedPacket(new_packet.sequence_number,
	new_packet.arrival_time_ms * 1000));
	EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(0);
	adapter_->OnTransportFeedback(second_feedback);
	}

	#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
	TEST_F(LegacyTransportFeedbackAdapterTest,
	ObserverDoubleRegistrationDeathTest) {
	MockPacketFeedbackObserver mock;
	adapter_->RegisterPacketFeedbackObserver(&mock);
	EXPECT_DEATH(adapter_->RegisterPacketFeedbackObserver(&mock), "");
	adapter_->DeRegisterPacketFeedbackObserver(&mock);
	}

	TEST_F(LegacyTransportFeedbackAdapterTest,
	ObserverMissingDeRegistrationDeathTest) {
	MockPacketFeedbackObserver mock;
	adapter_->RegisterPacketFeedbackObserver(&mock);
	EXPECT_DEATH(adapter_.reset(), "");
	adapter_->DeRegisterPacketFeedbackObserver(&mock);
	}
	#endif

	TEST_F(LegacyTransportFeedbackAdapterTest,
	AdaptsFeedbackAndPopulatesSendTimes) {
	std::vector<PacketFeedback> packets;
	packets.push_back(PacketFeedback(100, 200, 0, 1500, kPacingInfo0));
	packets.push_back(PacketFeedback(110, 210, 1, 1500, kPacingInfo0));
	packets.push_back(PacketFeedback(120, 220, 2, 1500, kPacingInfo0));
	packets.push_back(PacketFeedback(130, 230, 3, 1500, kPacingInfo1));
	packets.push_back(PacketFeedback(140, 240, 4, 1500, kPacingInfo1));

	for (const PacketFeedback& packet : packets)
	OnSentPacket(packet);

	rtcp::TransportFeedback feedback;
	feedback.SetBase(packets[0].sequence_number,
	packets[0].arrival_time_ms * 1000);

	for (const PacketFeedback& packet : packets) {
	EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
	packet.arrival_time_ms * 1000));
	}

	feedback.Build();

	adapter_->OnTransportFeedback(feedback);
	ComparePacketFeedbackVectors(packets, adapter_->GetTransportFeedbackVector());
	}

	TEST_F(LegacyTransportFeedbackAdapterTest, FeedbackVectorReportsUnreceived) {
	std::vector<PacketFeedback> sent_packets = {
	PacketFeedback(100, 220, 0, 1500, kPacingInfo0),
	PacketFeedback(110, 210, 1, 1500, kPacingInfo0),
	PacketFeedback(120, 220, 2, 1500, kPacingInfo0),
	PacketFeedback(130, 230, 3, 1500, kPacingInfo0),
	PacketFeedback(140, 240, 4, 1500, kPacingInfo0),
	PacketFeedback(150, 250, 5, 1500, kPacingInfo0),
	PacketFeedback(160, 260, 6, 1500, kPacingInfo0)
	};

	for (const PacketFeedback& packet : sent_packets)
	OnSentPacket(packet);

	// Note: Important to include the last packet, as only unreceived packets in
	// between received packets can be inferred.
	std::vector<PacketFeedback> received_packets = {
	sent_packets[0], sent_packets[2], sent_packets[6]
	};

	rtcp::TransportFeedback feedback;
	feedback.SetBase(received_packets[0].sequence_number,
	received_packets[0].arrival_time_ms * 1000);

	for (const PacketFeedback& packet : received_packets) {
	EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
	packet.arrival_time_ms * 1000));
	}

	feedback.Build();

	adapter_->OnTransportFeedback(feedback);
	ComparePacketFeedbackVectors(sent_packets,
	adapter_->GetTransportFeedbackVector());
	}

	TEST_F(LegacyTransportFeedbackAdapterTest, HandlesDroppedPackets) {
	std::vector<PacketFeedback> packets;
	packets.push_back(PacketFeedback(100, 200, 0, 1500, kPacingInfo0));
	packets.push_back(PacketFeedback(110, 210, 1, 1500, kPacingInfo1));
	packets.push_back(PacketFeedback(120, 220, 2, 1500, kPacingInfo2));
	packets.push_back(PacketFeedback(130, 230, 3, 1500, kPacingInfo3));
	packets.push_back(PacketFeedback(140, 240, 4, 1500, kPacingInfo4));

	const uint16_t kSendSideDropBefore = 1;
	const uint16_t kReceiveSideDropAfter = 3;

	for (const PacketFeedback& packet : packets) {
	if (packet.sequence_number >= kSendSideDropBefore)
	OnSentPacket(packet);
	}

	rtcp::TransportFeedback feedback;
	feedback.SetBase(packets[0].sequence_number,
	packets[0].arrival_time_ms * 1000);

	for (const PacketFeedback& packet : packets) {
	if (packet.sequence_number <= kReceiveSideDropAfter) {
	EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
	packet.arrival_time_ms * 1000));
	}
	}

	feedback.Build();

	std::vector<PacketFeedback> expected_packets(
	packets.begin(), packets.begin() + kReceiveSideDropAfter + 1);
	// Packets that have timed out on the send-side have lost the
	// information stored on the send-side.
	for (size_t i = 0; i < kSendSideDropBefore; ++i) {
	expected_packets[i].send_time_ms = -1;
	expected_packets[i].payload_size = 0;
	expected_packets[i].pacing_info = PacedPacketInfo();
	}

	adapter_->OnTransportFeedback(feedback);
	ComparePacketFeedbackVectors(expected_packets,
	adapter_->GetTransportFeedbackVector());
	}

	TEST_F(LegacyTransportFeedbackAdapterTest, SendTimeWrapsBothWays) {
	int64_t kHighArrivalTimeMs = rtcp::TransportFeedback::kDeltaScaleFactor *
	static_cast<int64_t>(1 << 8) *
	static_cast<int64_t>((1 << 23) - 1) / 1000;
	std::vector<PacketFeedback> packets;
	packets.push_back(
	PacketFeedback(kHighArrivalTimeMs - 64, 200, 0, 1500, PacedPacketInfo()));
	packets.push_back(
	PacketFeedback(kHighArrivalTimeMs + 64, 210, 1, 1500, PacedPacketInfo()));
	packets.push_back(
	PacketFeedback(kHighArrivalTimeMs, 220, 2, 1500, PacedPacketInfo()));

	for (const PacketFeedback& packet : packets)
	OnSentPacket(packet);

	for (size_t i = 0; i < packets.size(); ++i) {
	std::unique_ptr<rtcp::TransportFeedback> feedback(
	new rtcp::TransportFeedback());
	feedback->SetBase(packets[i].sequence_number,
	packets[i].arrival_time_ms * 1000);

	EXPECT_TRUE(feedback->AddReceivedPacket(packets[i].sequence_number,
	packets[i].arrival_time_ms * 1000));

	rtc::Buffer raw_packet = feedback->Build();
	feedback = rtcp::TransportFeedback::ParseFrom(raw_packet.data(),
	raw_packet.size());

	std::vector<PacketFeedback> expected_packets;
	expected_packets.push_back(packets[i]);

	adapter_->OnTransportFeedback(*feedback.get());
	ComparePacketFeedbackVectors(expected_packets,
	adapter_->GetTransportFeedbackVector());
	}
	}

	TEST_F(LegacyTransportFeedbackAdapterTest, HandlesArrivalReordering) {
	std::vector<PacketFeedback> packets;
	packets.push_back(PacketFeedback(120, 200, 0, 1500, kPacingInfo0));
	packets.push_back(PacketFeedback(110, 210, 1, 1500, kPacingInfo0));
	packets.push_back(PacketFeedback(100, 220, 2, 1500, kPacingInfo0));

	for (const PacketFeedback& packet : packets)
	OnSentPacket(packet);

	rtcp::TransportFeedback feedback;
	feedback.SetBase(packets[0].sequence_number,
	packets[0].arrival_time_ms * 1000);

	for (const PacketFeedback& packet : packets) {
	EXPECT_TRUE(feedback.AddReceivedPacket(packet.sequence_number,
	packet.arrival_time_ms * 1000));
	}

	feedback.Build();

	// Adapter keeps the packets ordered by sequence number (which is itself
	// assigned by the order of transmission). Reordering by some other criteria,
	// eg. arrival time, is up to the observers.
	adapter_->OnTransportFeedback(feedback);
	ComparePacketFeedbackVectors(packets, adapter_->GetTransportFeedbackVector());
	}

	TEST_F(LegacyTransportFeedbackAdapterTest, TimestampDeltas) {
	std::vector<PacketFeedback> sent_packets;
	const int64_t kSmallDeltaUs =
	rtcp::TransportFeedback::kDeltaScaleFactor * ((1 << 8) - 1);
	const int64_t kLargePositiveDeltaUs =
	rtcp::TransportFeedback::kDeltaScaleFactor *
	std::numeric_limits<int16_t>::max();
	const int64_t kLargeNegativeDeltaUs =
	rtcp::TransportFeedback::kDeltaScaleFactor *
	std::numeric_limits<int16_t>::min();

	PacketFeedback packet_feedback(100, 200, 0, 1500, true, 0, 0,
	PacedPacketInfo());
	sent_packets.push_back(packet_feedback);

	packet_feedback.send_time_ms += kSmallDeltaUs / 1000;
	packet_feedback.arrival_time_ms += kSmallDeltaUs / 1000;
	++packet_feedback.sequence_number;
	sent_packets.push_back(packet_feedback);

	packet_feedback.send_time_ms += kLargePositiveDeltaUs / 1000;
	packet_feedback.arrival_time_ms += kLargePositiveDeltaUs / 1000;
	++packet_feedback.sequence_number;
	sent_packets.push_back(packet_feedback);

	packet_feedback.send_time_ms += kLargeNegativeDeltaUs / 1000;
	packet_feedback.arrival_time_ms += kLargeNegativeDeltaUs / 1000;
	++packet_feedback.sequence_number;
	sent_packets.push_back(packet_feedback);

	// Too large, delta - will need two feedback messages.
	packet_feedback.send_time_ms += (kLargePositiveDeltaUs + 1000) / 1000;
	packet_feedback.arrival_time_ms += (kLargePositiveDeltaUs + 1000) / 1000;
	++packet_feedback.sequence_number;

	// Packets will be added to send history.
	for (const PacketFeedback& packet : sent_packets)
	OnSentPacket(packet);
	OnSentPacket(packet_feedback);

	// Create expected feedback and send into adapter.
	std::unique_ptr<rtcp::TransportFeedback> feedback(
	new rtcp::TransportFeedback());
	feedback->SetBase(sent_packets[0].sequence_number,
	sent_packets[0].arrival_time_ms * 1000);

	for (const PacketFeedback& packet : sent_packets) {
	EXPECT_TRUE(feedback->AddReceivedPacket(packet.sequence_number,
	packet.arrival_time_ms * 1000));
	}
	EXPECT_FALSE(feedback->AddReceivedPacket(
	packet_feedback.sequence_number, packet_feedback.arrival_time_ms * 1000));

	rtc::Buffer raw_packet = feedback->Build();
	feedback =
	rtcp::TransportFeedback::ParseFrom(raw_packet.data(), raw_packet.size());

	std::vector<PacketFeedback> received_feedback;

	EXPECT_TRUE(feedback.get() != nullptr);
	adapter_->OnTransportFeedback(*feedback.get());
	ComparePacketFeedbackVectors(sent_packets,
	adapter_->GetTransportFeedbackVector());

	// Create a new feedback message and add the trailing item.
	feedback.reset(new rtcp::TransportFeedback());
	feedback->SetBase(packet_feedback.sequence_number,
	packet_feedback.arrival_time_ms * 1000);
	EXPECT_TRUE(feedback->AddReceivedPacket(
	packet_feedback.sequence_number, packet_feedback.arrival_time_ms * 1000));
	raw_packet = feedback->Build();
	feedback =
	rtcp::TransportFeedback::ParseFrom(raw_packet.data(), raw_packet.size());

	EXPECT_TRUE(feedback.get() != nullptr);
	adapter_->OnTransportFeedback(*feedback.get());
	{
	std::vector<PacketFeedback> expected_packets;
	expected_packets.push_back(packet_feedback);
	ComparePacketFeedbackVectors(expected_packets,
	adapter_->GetTransportFeedbackVector());
	}
	}
	} // namespace test
	} // namespace webrtc