webrtc/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 "webrtc/test/gmock.h"
 #include "webrtc/test/gtest.h"

 #include "webrtc/base/checks.h"
 #include "webrtc/modules/bitrate_controller/include/mock/mock_bitrate_controller.h"
 #include "webrtc/modules/congestion_controller/transport_feedback_adapter.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
 #include "webrtc/system_wrappers/include/clock.h"

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

 namespace webrtc {
 namespace test {

 class TransportFeedbackAdapterTest : public ::testing::Test {
  public:
   TransportFeedbackAdapterTest()
       : clock_(0), bitrate_controller_(this), target_bitrate_bps_(0) {}

   virtual ~TransportFeedbackAdapterTest() {}

   virtual void SetUp() {
     adapter_.reset(new TransportFeedbackAdapter(&clock_, &bitrate_controller_));
     adapter_->InitBwe();
   }

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

  protected:
   // Proxy class used since TransportFeedbackAdapter will own the instance
   // passed at construction.
   class MockBitrateControllerAdapter : public MockBitrateController {
    public:
     explicit MockBitrateControllerAdapter(TransportFeedbackAdapterTest* owner)
         : MockBitrateController(), owner_(owner) {}

     ~MockBitrateControllerAdapter() override {}

     void OnDelayBasedBweResult(const DelayBasedBwe::Result& result) override {
       owner_->target_bitrate_bps_ = result.target_bitrate_bps;
     }

     TransportFeedbackAdapterTest* const owner_;
   };

   void OnReceivedEstimatedBitrate(uint32_t bitrate) {}

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

   void ComparePacketVectors(const std::vector<PacketInfo>& truth,
                             const std::vector<PacketInfo>& input) {
     ASSERT_EQ(truth.size(), input.size());
     size_t len = truth.size();
     // truth contains the input data for the test, and input is what will be
     // sent to the bandwidth estimator. truth.arrival_tims_ms is used to
     // populate the transport feedback messages. As these times may be changed
     // (because of resolution limits in the packets, and because of the time
     // base adjustment performed by the TransportFeedbackAdapter at the first
     // packet, the truth[x].arrival_time and input[x].arrival_time may not be
     // equal. However, the difference must be the same for all x.
     int64_t arrival_time_delta =
         truth[0].arrival_time_ms - input[0].arrival_time_ms;
     for (size_t i = 0; i < len; ++i) {
       EXPECT_EQ(truth[i].arrival_time_ms,
                 input[i].arrival_time_ms + arrival_time_delta);
       EXPECT_EQ(truth[i].send_time_ms, input[i].send_time_ms);
       EXPECT_EQ(truth[i].sequence_number, input[i].sequence_number);
       EXPECT_EQ(truth[i].payload_size, input[i].payload_size);
       EXPECT_EQ(truth[i].probe_cluster_id, input[i].probe_cluster_id);
     }
   }

   // Utility method, to reset arrival_time_ms before adding send time.
   void OnSentPacket(PacketInfo info) {
     info.arrival_time_ms = 0;
     adapter_->AddPacket(info.sequence_number, info.payload_size,
                         info.probe_cluster_id);
     adapter_->OnSentPacket(info.sequence_number, info.send_time_ms);
   }

   SimulatedClock clock_;
   MockBitrateControllerAdapter bitrate_controller_;
   std::unique_ptr<TransportFeedbackAdapter> adapter_;

   uint32_t target_bitrate_bps_;
 };

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

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

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

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

   feedback.Build();

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

 TEST_F(TransportFeedbackAdapterTest, HandlesDroppedPackets) {
   std::vector<PacketInfo> packets;
   packets.push_back(PacketInfo(100, 200, 0, 1500, 1));
   packets.push_back(PacketInfo(110, 210, 1, 1500, 2));
   packets.push_back(PacketInfo(120, 220, 2, 1500, 3));
   packets.push_back(PacketInfo(130, 230, 3, 1500, 4));
   packets.push_back(PacketInfo(140, 240, 4, 1500, 5));

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

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

   feedback.Build();

   std::vector<PacketInfo> expected_packets(
       packets.begin() + kSendSideDropBefore,
       packets.begin() + kReceiveSideDropAfter + 1);

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

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

   for (const PacketInfo& 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<PacketInfo> expected_packets;
     expected_packets.push_back(packets[i]);

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

 TEST_F(TransportFeedbackAdapterTest, HandlesReordering) {
   std::vector<PacketInfo> packets;
   packets.push_back(PacketInfo(120, 200, 0, 1500, 0));
   packets.push_back(PacketInfo(110, 210, 1, 1500, 0));
   packets.push_back(PacketInfo(100, 220, 2, 1500, 0));
   std::vector<PacketInfo> expected_packets;
   expected_packets.push_back(packets[2]);
   expected_packets.push_back(packets[1]);
   expected_packets.push_back(packets[0]);

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

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

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

   feedback.Build();

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

 TEST_F(TransportFeedbackAdapterTest, TimestampDeltas) {
   std::vector<PacketInfo> 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();

   PacketInfo info(100, 200, 0, 1500, true, PacketInfo::kNotAProbe);
   sent_packets.push_back(info);

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

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

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

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

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

   // 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 PacketInfo& packet : sent_packets) {
     EXPECT_TRUE(feedback->AddReceivedPacket(packet.sequence_number,
                                             packet.arrival_time_ms * 1000));
   }
   EXPECT_FALSE(feedback->AddReceivedPacket(info.sequence_number,
                                            info.arrival_time_ms * 1000));

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

   std::vector<PacketInfo> received_feedback;

   EXPECT_TRUE(feedback.get() != nullptr);
   adapter_->OnTransportFeedback(*feedback.get());
   {
     // Expected to be ordered on arrival time when the feedback message has been
     // parsed.
     std::vector<PacketInfo> expected_packets;
     expected_packets.push_back(sent_packets[0]);
     expected_packets.push_back(sent_packets[3]);
     expected_packets.push_back(sent_packets[1]);
     expected_packets.push_back(sent_packets[2]);
     ComparePacketVectors(expected_packets,
                          adapter_->GetTransportFeedbackVector());
   }

   // Create a new feedback message and add the trailing item.
   feedback.reset(new rtcp::TransportFeedback());
   feedback->SetBase(info.sequence_number, info.arrival_time_ms * 1000);
   EXPECT_TRUE(feedback->AddReceivedPacket(info.sequence_number,
                                           info.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<PacketInfo> expected_packets;
     expected_packets.push_back(info);
     ComparePacketVectors(expected_packets,
                          adapter_->GetTransportFeedbackVector());
   }
 }

 TEST_F(TransportFeedbackAdapterTest, UpdatesDelayBasedEstimate) {
   uint16_t seq_num = 0;
   size_t kPayloadSize = 1000;
   // The test must run and insert packets/feedback long enough that the
   // BWE computes a valid estimate.
   const int64_t kRunTimeMs = 6000;
   int64_t start_time_ms = clock_.TimeInMilliseconds();
   while (clock_.TimeInMilliseconds() - start_time_ms < kRunTimeMs) {
     PacketInfo packet(clock_.TimeInMilliseconds(), clock_.TimeInMilliseconds(),
                       seq_num, kPayloadSize, PacketInfo::kNotAProbe);
     OnSentPacket(packet);
     // Create expected feedback and send into adapter.
     std::unique_ptr<rtcp::TransportFeedback> feedback(
         new rtcp::TransportFeedback());
     feedback->SetBase(packet.sequence_number, packet.arrival_time_ms * 1000);
     EXPECT_TRUE(feedback->AddReceivedPacket(packet.sequence_number,
                                             packet.arrival_time_ms * 1000));
     rtc::Buffer raw_packet = feedback->Build();
     feedback = rtcp::TransportFeedback::ParseFrom(raw_packet.data(),
                                                   raw_packet.size());
     EXPECT_TRUE(feedback.get() != nullptr);
     adapter_->OnTransportFeedback(*feedback.get());
     clock_.AdvanceTimeMilliseconds(50);
     ++seq_num;
   }
   EXPECT_GT(target_bitrate_bps_, 0u);
 }

 }  // 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 "webrtc/test/gmock.h"
	#include "webrtc/test/gtest.h"

	#include "webrtc/base/checks.h"
	#include "webrtc/modules/bitrate_controller/include/mock/mock_bitrate_controller.h"
	#include "webrtc/modules/congestion_controller/transport_feedback_adapter.h"
	#include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
	#include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
	#include "webrtc/system_wrappers/include/clock.h"

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

	namespace webrtc {
	namespace test {

	class TransportFeedbackAdapterTest : public ::testing::Test {
	public:
	TransportFeedbackAdapterTest()
	: clock_(0), bitrate_controller_(this), target_bitrate_bps_(0) {}

	virtual ~TransportFeedbackAdapterTest() {}

	virtual void SetUp() {
	adapter_.reset(new TransportFeedbackAdapter(&clock_, &bitrate_controller_));
	adapter_->InitBwe();
	}

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

	protected:
	// Proxy class used since TransportFeedbackAdapter will own the instance
	// passed at construction.
	class MockBitrateControllerAdapter : public MockBitrateController {
	public:
	explicit MockBitrateControllerAdapter(TransportFeedbackAdapterTest* owner)
	: MockBitrateController(), owner_(owner) {}

	~MockBitrateControllerAdapter() override {}

	void OnDelayBasedBweResult(const DelayBasedBwe::Result& result) override {
	owner_->target_bitrate_bps_ = result.target_bitrate_bps;
	}

	TransportFeedbackAdapterTest* const owner_;
	};

	void OnReceivedEstimatedBitrate(uint32_t bitrate) {}

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

	void ComparePacketVectors(const std::vector<PacketInfo>& truth,
	const std::vector<PacketInfo>& input) {
	ASSERT_EQ(truth.size(), input.size());
	size_t len = truth.size();
	// truth contains the input data for the test, and input is what will be
	// sent to the bandwidth estimator. truth.arrival_tims_ms is used to
	// populate the transport feedback messages. As these times may be changed
	// (because of resolution limits in the packets, and because of the time
	// base adjustment performed by the TransportFeedbackAdapter at the first
	// packet, the truth[x].arrival_time and input[x].arrival_time may not be
	// equal. However, the difference must be the same for all x.
	int64_t arrival_time_delta =
	truth[0].arrival_time_ms - input[0].arrival_time_ms;
	for (size_t i = 0; i < len; ++i) {
	EXPECT_EQ(truth[i].arrival_time_ms,
	input[i].arrival_time_ms + arrival_time_delta);
	EXPECT_EQ(truth[i].send_time_ms, input[i].send_time_ms);
	EXPECT_EQ(truth[i].sequence_number, input[i].sequence_number);
	EXPECT_EQ(truth[i].payload_size, input[i].payload_size);
	EXPECT_EQ(truth[i].probe_cluster_id, input[i].probe_cluster_id);
	}
	}

	// Utility method, to reset arrival_time_ms before adding send time.
	void OnSentPacket(PacketInfo info) {
	info.arrival_time_ms = 0;
	adapter_->AddPacket(info.sequence_number, info.payload_size,
	info.probe_cluster_id);
	adapter_->OnSentPacket(info.sequence_number, info.send_time_ms);
	}

	SimulatedClock clock_;
	MockBitrateControllerAdapter bitrate_controller_;
	std::unique_ptr<TransportFeedbackAdapter> adapter_;

	uint32_t target_bitrate_bps_;
	};

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

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

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

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

	feedback.Build();

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

	TEST_F(TransportFeedbackAdapterTest, HandlesDroppedPackets) {
	std::vector<PacketInfo> packets;
	packets.push_back(PacketInfo(100, 200, 0, 1500, 1));
	packets.push_back(PacketInfo(110, 210, 1, 1500, 2));
	packets.push_back(PacketInfo(120, 220, 2, 1500, 3));
	packets.push_back(PacketInfo(130, 230, 3, 1500, 4));
	packets.push_back(PacketInfo(140, 240, 4, 1500, 5));

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

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

	feedback.Build();

	std::vector<PacketInfo> expected_packets(
	packets.begin() + kSendSideDropBefore,
	packets.begin() + kReceiveSideDropAfter + 1);

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

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

	for (const PacketInfo& 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<PacketInfo> expected_packets;
	expected_packets.push_back(packets[i]);

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

	TEST_F(TransportFeedbackAdapterTest, HandlesReordering) {
	std::vector<PacketInfo> packets;
	packets.push_back(PacketInfo(120, 200, 0, 1500, 0));
	packets.push_back(PacketInfo(110, 210, 1, 1500, 0));
	packets.push_back(PacketInfo(100, 220, 2, 1500, 0));
	std::vector<PacketInfo> expected_packets;
	expected_packets.push_back(packets[2]);
	expected_packets.push_back(packets[1]);
	expected_packets.push_back(packets[0]);

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

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

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

	feedback.Build();

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

	TEST_F(TransportFeedbackAdapterTest, TimestampDeltas) {
	std::vector<PacketInfo> 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();

	PacketInfo info(100, 200, 0, 1500, true, PacketInfo::kNotAProbe);
	sent_packets.push_back(info);

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

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

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

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

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

	// 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 PacketInfo& packet : sent_packets) {
	EXPECT_TRUE(feedback->AddReceivedPacket(packet.sequence_number,
	packet.arrival_time_ms * 1000));
	}
	EXPECT_FALSE(feedback->AddReceivedPacket(info.sequence_number,
	info.arrival_time_ms * 1000));

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

	std::vector<PacketInfo> received_feedback;

	EXPECT_TRUE(feedback.get() != nullptr);
	adapter_->OnTransportFeedback(*feedback.get());
	{
	// Expected to be ordered on arrival time when the feedback message has been
	// parsed.
	std::vector<PacketInfo> expected_packets;
	expected_packets.push_back(sent_packets[0]);
	expected_packets.push_back(sent_packets[3]);
	expected_packets.push_back(sent_packets[1]);
	expected_packets.push_back(sent_packets[2]);
	ComparePacketVectors(expected_packets,
	adapter_->GetTransportFeedbackVector());
	}

	// Create a new feedback message and add the trailing item.
	feedback.reset(new rtcp::TransportFeedback());
	feedback->SetBase(info.sequence_number, info.arrival_time_ms * 1000);
	EXPECT_TRUE(feedback->AddReceivedPacket(info.sequence_number,
	info.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<PacketInfo> expected_packets;
	expected_packets.push_back(info);
	ComparePacketVectors(expected_packets,
	adapter_->GetTransportFeedbackVector());
	}
	}

	TEST_F(TransportFeedbackAdapterTest, UpdatesDelayBasedEstimate) {
	uint16_t seq_num = 0;
	size_t kPayloadSize = 1000;
	// The test must run and insert packets/feedback long enough that the
	// BWE computes a valid estimate.
	const int64_t kRunTimeMs = 6000;
	int64_t start_time_ms = clock_.TimeInMilliseconds();
	while (clock_.TimeInMilliseconds() - start_time_ms < kRunTimeMs) {
	PacketInfo packet(clock_.TimeInMilliseconds(), clock_.TimeInMilliseconds(),
	seq_num, kPayloadSize, PacketInfo::kNotAProbe);
	OnSentPacket(packet);
	// Create expected feedback and send into adapter.
	std::unique_ptr<rtcp::TransportFeedback> feedback(
	new rtcp::TransportFeedback());
	feedback->SetBase(packet.sequence_number, packet.arrival_time_ms * 1000);
	EXPECT_TRUE(feedback->AddReceivedPacket(packet.sequence_number,
	packet.arrival_time_ms * 1000));
	rtc::Buffer raw_packet = feedback->Build();
	feedback = rtcp::TransportFeedback::ParseFrom(raw_packet.data(),
	raw_packet.size());
	EXPECT_TRUE(feedback.get() != nullptr);
	adapter_->OnTransportFeedback(*feedback.get());
	clock_.AdvanceTimeMilliseconds(50);
	++seq_num;
	}
	EXPECT_GT(target_bitrate_bps_, 0u);
	}

	} // namespace test
	} // namespace webrtc