video/end_to_end_tests/network_state_tests.cc - src - Git at Google

 /*
  *  Copyright 2018 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 <memory>

 #include "api/media_types.h"
 #include "api/task_queue/default_task_queue_factory.h"
 #include "api/task_queue/task_queue_base.h"
 #include "api/task_queue/task_queue_factory.h"
 #include "api/test/simulated_network.h"
 #include "api/video_codecs/video_encoder.h"
 #include "call/fake_network_pipe.h"
 #include "call/simulated_network.h"
 #include "modules/rtp_rtcp/source/rtp_packet.h"
 #include "rtc_base/synchronization/mutex.h"
 #include "rtc_base/task_queue_for_test.h"
 #include "system_wrappers/include/sleep.h"
 #include "test/call_test.h"
 #include "test/fake_encoder.h"
 #include "test/gtest.h"
 #include "test/video_encoder_proxy_factory.h"

 namespace webrtc {
 namespace {
 constexpr int kSilenceTimeoutMs = 2000;
 }

 class NetworkStateEndToEndTest : public test::CallTest {
  protected:
   class UnusedTransport : public Transport {
    private:
     bool SendRtp(const uint8_t* packet,
                  size_t length,
                  const PacketOptions& options) override {
       ADD_FAILURE() << "Unexpected RTP sent.";
       return false;
     }

     bool SendRtcp(const uint8_t* packet, size_t length) override {
       ADD_FAILURE() << "Unexpected RTCP sent.";
       return false;
     }
   };
   class RequiredTransport : public Transport {
    public:
     RequiredTransport(bool rtp_required, bool rtcp_required)
         : need_rtp_(rtp_required), need_rtcp_(rtcp_required) {}
     ~RequiredTransport() {
       if (need_rtp_) {
         ADD_FAILURE() << "Expected RTP packet not sent.";
       }
       if (need_rtcp_) {
         ADD_FAILURE() << "Expected RTCP packet not sent.";
       }
     }

    private:
     bool SendRtp(const uint8_t* packet,
                  size_t length,
                  const PacketOptions& options) override {
       MutexLock lock(&mutex_);
       need_rtp_ = false;
       return true;
     }

     bool SendRtcp(const uint8_t* packet, size_t length) override {
       MutexLock lock(&mutex_);
       need_rtcp_ = false;
       return true;
     }
     bool need_rtp_;
     bool need_rtcp_;
     Mutex mutex_;
   };
   void VerifyNewVideoSendStreamsRespectNetworkState(
       MediaType network_to_bring_up,
       VideoEncoder* encoder,
       Transport* transport);
   void VerifyNewVideoReceiveStreamsRespectNetworkState(
       MediaType network_to_bring_up,
       Transport* transport);
 };

 void NetworkStateEndToEndTest::VerifyNewVideoSendStreamsRespectNetworkState(
     MediaType network_to_bring_up,
     VideoEncoder* encoder,
     Transport* transport) {
   test::VideoEncoderProxyFactory encoder_factory(encoder);

   SendTask(task_queue(), [this, network_to_bring_up, &encoder_factory,
                           transport]() {
     CreateSenderCall(Call::Config(send_event_log_.get()));
     sender_call_->SignalChannelNetworkState(network_to_bring_up, kNetworkUp);

     CreateSendConfig(1, 0, 0, transport);
     GetVideoSendConfig()->encoder_settings.encoder_factory = &encoder_factory;
     CreateVideoStreams();
     CreateFrameGeneratorCapturer(test::VideoTestConstants::kDefaultFramerate,
                                  test::VideoTestConstants::kDefaultWidth,
                                  test::VideoTestConstants::kDefaultHeight);

     Start();
   });

   SleepMs(kSilenceTimeoutMs);

   SendTask(task_queue(), [this]() {
     Stop();
     DestroyStreams();
     DestroyCalls();
   });
 }

 void NetworkStateEndToEndTest::VerifyNewVideoReceiveStreamsRespectNetworkState(
     MediaType network_to_bring_up,
     Transport* transport) {
   SendTask(task_queue(), [this, network_to_bring_up, transport]() {
     CreateCalls();
     receiver_call_->SignalChannelNetworkState(network_to_bring_up, kNetworkUp);
     CreateSendTransport(BuiltInNetworkBehaviorConfig(),
                         /*observer=*/nullptr);

     CreateSendConfig(1, 0, 0);
     CreateMatchingReceiveConfigs(transport);
     CreateVideoStreams();
     CreateFrameGeneratorCapturer(test::VideoTestConstants::kDefaultFramerate,
                                  test::VideoTestConstants::kDefaultWidth,
                                  test::VideoTestConstants::kDefaultHeight);
     Start();
   });

   SleepMs(kSilenceTimeoutMs);

   SendTask(task_queue(), [this]() {
     Stop();
     DestroyStreams();
     DestroyCalls();
   });
 }

 TEST_F(NetworkStateEndToEndTest, RespectsNetworkState) {
   // TODO(pbos): Remove accepted downtime packets etc. when signaling network
   // down blocks until no more packets will be sent.

   // Pacer will send from its packet list and then send required padding before
   // checking paused_ again. This should be enough for one round of pacing,
   // otherwise increase.
   static const int kNumAcceptedDowntimeRtp = 5;
   // A single RTCP may be in the pipeline.
   static const int kNumAcceptedDowntimeRtcp = 1;
   class NetworkStateTest : public test::EndToEndTest, public test::FakeEncoder {
    public:
     explicit NetworkStateTest(TaskQueueBase* task_queue)
         : EndToEndTest(test::VideoTestConstants::kDefaultTimeout),
           FakeEncoder(Clock::GetRealTimeClock()),
           e2e_test_task_queue_(task_queue),
           task_queue_(CreateDefaultTaskQueueFactory()->CreateTaskQueue(
               "NetworkStateTest",
               TaskQueueFactory::Priority::NORMAL)),
           sender_call_(nullptr),
           receiver_call_(nullptr),
           encoder_factory_(this),
           sender_state_(kNetworkUp),
           sender_rtp_(0),
           sender_padding_(0),
           sender_rtcp_(0),
           receiver_rtcp_(0),
           down_frames_(0) {}

     Action OnSendRtp(const uint8_t* packet, size_t length) override {
       MutexLock lock(&test_mutex_);
       RtpPacket rtp_packet;
       EXPECT_TRUE(rtp_packet.Parse(packet, length));
       if (rtp_packet.payload_size() == 0)
         ++sender_padding_;
       ++sender_rtp_;
       packet_event_.Set();
       return SEND_PACKET;
     }

     Action OnSendRtcp(const uint8_t* packet, size_t length) override {
       MutexLock lock(&test_mutex_);
       ++sender_rtcp_;
       packet_event_.Set();
       return SEND_PACKET;
     }

     Action OnReceiveRtp(const uint8_t* packet, size_t length) override {
       ADD_FAILURE() << "Unexpected receiver RTP, should not be sending.";
       return SEND_PACKET;
     }

     Action OnReceiveRtcp(const uint8_t* packet, size_t length) override {
       MutexLock lock(&test_mutex_);
       ++receiver_rtcp_;
       packet_event_.Set();
       return SEND_PACKET;
     }

     void OnCallsCreated(Call* sender_call, Call* receiver_call) override {
       sender_call_ = sender_call;
       receiver_call_ = receiver_call;
     }

     void ModifyVideoConfigs(
         VideoSendStream::Config* send_config,
         std::vector<VideoReceiveStreamInterface::Config>* receive_configs,
         VideoEncoderConfig* encoder_config) override {
       send_config->encoder_settings.encoder_factory = &encoder_factory_;
     }

     void SignalChannelNetworkState(Call* call,
                                    MediaType media_type,
                                    NetworkState network_state) {
       SendTask(e2e_test_task_queue_, [call, media_type, network_state] {
         call->SignalChannelNetworkState(media_type, network_state);
       });
     }

     void PerformTest() override {
       EXPECT_TRUE(
           encoded_frames_.Wait(test::VideoTestConstants::kDefaultTimeout))
           << "No frames received by the encoder.";

       SendTask(task_queue_.get(), [this]() {
         // Wait for packets from both sender/receiver.
         WaitForPacketsOrSilence(false, false);

         // Sender-side network down for audio; there should be no effect on
         // video
         SignalChannelNetworkState(sender_call_, MediaType::AUDIO, kNetworkDown);

         WaitForPacketsOrSilence(false, false);

         // Receiver-side network down for audio; no change expected
         SignalChannelNetworkState(receiver_call_, MediaType::AUDIO,
                                   kNetworkDown);
         WaitForPacketsOrSilence(false, false);

         // Sender-side network down.
         SignalChannelNetworkState(sender_call_, MediaType::VIDEO, kNetworkDown);
         {
           MutexLock lock(&test_mutex_);
           // After network goes down we shouldn't be encoding more frames.
           sender_state_ = kNetworkDown;
         }
         // Wait for receiver-packets and no sender packets.
         WaitForPacketsOrSilence(true, false);

         // Receiver-side network down.
         SignalChannelNetworkState(receiver_call_, MediaType::VIDEO,
                                   kNetworkDown);
         WaitForPacketsOrSilence(true, true);

         // Network up for audio for both sides; video is still not expected to
         // start
         SignalChannelNetworkState(sender_call_, MediaType::AUDIO, kNetworkUp);
         SignalChannelNetworkState(receiver_call_, MediaType::AUDIO, kNetworkUp);
         WaitForPacketsOrSilence(true, true);

         // Network back up again for both.
         {
           MutexLock lock(&test_mutex_);
           // It's OK to encode frames again, as we're about to bring up the
           // network.
           sender_state_ = kNetworkUp;
         }
         SignalChannelNetworkState(sender_call_, MediaType::VIDEO, kNetworkUp);
         SignalChannelNetworkState(receiver_call_, MediaType::VIDEO, kNetworkUp);
         WaitForPacketsOrSilence(false, false);

         // TODO(skvlad): add tests to verify that the audio streams are stopped
         // when the network goes down for audio once the workaround in
         // paced_sender.cc is removed.
       });
     }

     int32_t Encode(const VideoFrame& input_image,
                    const std::vector<VideoFrameType>* frame_types) override {
       {
         MutexLock lock(&test_mutex_);
         if (sender_state_ == kNetworkDown) {
           ++down_frames_;
           EXPECT_LE(down_frames_, 1)
               << "Encoding more than one frame while network is down.";
           if (down_frames_ > 1)
             encoded_frames_.Set();
         } else {
           encoded_frames_.Set();
         }
       }
       return test::FakeEncoder::Encode(input_image, frame_types);
     }

    private:
     void WaitForPacketsOrSilence(bool sender_down, bool receiver_down) {
       int64_t initial_time_ms = clock_->TimeInMilliseconds();
       int initial_sender_rtp;
       int initial_sender_rtcp;
       int initial_receiver_rtcp;
       {
         MutexLock lock(&test_mutex_);
         initial_sender_rtp = sender_rtp_;
         initial_sender_rtcp = sender_rtcp_;
         initial_receiver_rtcp = receiver_rtcp_;
       }
       bool sender_done = false;
       bool receiver_done = false;
       while (!sender_done || !receiver_done) {
         packet_event_.Wait(TimeDelta::Millis(kSilenceTimeoutMs));
         int64_t time_now_ms = clock_->TimeInMilliseconds();
         MutexLock lock(&test_mutex_);
         if (sender_down) {
           ASSERT_LE(sender_rtp_ - initial_sender_rtp - sender_padding_,
                     kNumAcceptedDowntimeRtp)
               << "RTP sent during sender-side downtime.";
           ASSERT_LE(sender_rtcp_ - initial_sender_rtcp,
                     kNumAcceptedDowntimeRtcp)
               << "RTCP sent during sender-side downtime.";
           if (time_now_ms - initial_time_ms >=
               static_cast<int64_t>(kSilenceTimeoutMs)) {
             sender_done = true;
           }
         } else {
           if (sender_rtp_ > initial_sender_rtp + kNumAcceptedDowntimeRtp)
             sender_done = true;
         }
         if (receiver_down) {
           ASSERT_LE(receiver_rtcp_ - initial_receiver_rtcp,
                     kNumAcceptedDowntimeRtcp)
               << "RTCP sent during receiver-side downtime.";
           if (time_now_ms - initial_time_ms >=
               static_cast<int64_t>(kSilenceTimeoutMs)) {
             receiver_done = true;
           }
         } else {
           if (receiver_rtcp_ > initial_receiver_rtcp + kNumAcceptedDowntimeRtcp)
             receiver_done = true;
         }
       }
     }

     TaskQueueBase* const e2e_test_task_queue_;
     std::unique_ptr<TaskQueueBase, TaskQueueDeleter> task_queue_;
     Mutex test_mutex_;
     rtc::Event encoded_frames_;
     rtc::Event packet_event_;
     Call* sender_call_;
     Call* receiver_call_;
     test::VideoEncoderProxyFactory encoder_factory_;
     NetworkState sender_state_ RTC_GUARDED_BY(test_mutex_);
     int sender_rtp_ RTC_GUARDED_BY(test_mutex_);
     int sender_padding_ RTC_GUARDED_BY(test_mutex_);
     int sender_rtcp_ RTC_GUARDED_BY(test_mutex_);
     int receiver_rtcp_ RTC_GUARDED_BY(test_mutex_);
     int down_frames_ RTC_GUARDED_BY(test_mutex_);
   } test(task_queue());

   RunBaseTest(&test);
 }

 TEST_F(NetworkStateEndToEndTest, NewVideoSendStreamsRespectVideoNetworkDown) {
   class UnusedEncoder : public test::FakeEncoder {
    public:
     UnusedEncoder() : FakeEncoder(Clock::GetRealTimeClock()) {}

     int32_t InitEncode(const VideoCodec* config,
                        const Settings& settings) override {
       EXPECT_GT(config->startBitrate, 0u);
       return 0;
     }
     int32_t Encode(const VideoFrame& input_image,
                    const std::vector<VideoFrameType>* frame_types) override {
       ADD_FAILURE() << "Unexpected frame encode.";
       return test::FakeEncoder::Encode(input_image, frame_types);
     }
   };

   UnusedEncoder unused_encoder;
   UnusedTransport unused_transport;
   VerifyNewVideoSendStreamsRespectNetworkState(
       MediaType::AUDIO, &unused_encoder, &unused_transport);
 }

 TEST_F(NetworkStateEndToEndTest, NewVideoSendStreamsIgnoreAudioNetworkDown) {
   class RequiredEncoder : public test::FakeEncoder {
    public:
     RequiredEncoder()
         : FakeEncoder(Clock::GetRealTimeClock()), encoded_frame_(false) {}
     ~RequiredEncoder() {
       if (!encoded_frame_) {
         ADD_FAILURE() << "Didn't encode an expected frame";
       }
     }
     int32_t Encode(const VideoFrame& input_image,
                    const std::vector<VideoFrameType>* frame_types) override {
       encoded_frame_ = true;
       return test::FakeEncoder::Encode(input_image, frame_types);
     }

    private:
     bool encoded_frame_;
   };

   RequiredTransport required_transport(true /*rtp*/, false /*rtcp*/);
   RequiredEncoder required_encoder;
   VerifyNewVideoSendStreamsRespectNetworkState(
       MediaType::VIDEO, &required_encoder, &required_transport);
 }

 TEST_F(NetworkStateEndToEndTest,
        NewVideoReceiveStreamsRespectVideoNetworkDown) {
   UnusedTransport transport;
   VerifyNewVideoReceiveStreamsRespectNetworkState(MediaType::AUDIO, &transport);
 }

 TEST_F(NetworkStateEndToEndTest, NewVideoReceiveStreamsIgnoreAudioNetworkDown) {
   RequiredTransport transport(false /*rtp*/, true /*rtcp*/);
   VerifyNewVideoReceiveStreamsRespectNetworkState(MediaType::VIDEO, &transport);
 }

 }  // namespace webrtc
	/*
	* Copyright 2018 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 <memory>

	#include "api/media_types.h"
	#include "api/task_queue/default_task_queue_factory.h"
	#include "api/task_queue/task_queue_base.h"
	#include "api/task_queue/task_queue_factory.h"
	#include "api/test/simulated_network.h"
	#include "api/video_codecs/video_encoder.h"
	#include "call/fake_network_pipe.h"
	#include "call/simulated_network.h"
	#include "modules/rtp_rtcp/source/rtp_packet.h"
	#include "rtc_base/synchronization/mutex.h"
	#include "rtc_base/task_queue_for_test.h"
	#include "system_wrappers/include/sleep.h"
	#include "test/call_test.h"
	#include "test/fake_encoder.h"
	#include "test/gtest.h"
	#include "test/video_encoder_proxy_factory.h"

	namespace webrtc {
	namespace {
	constexpr int kSilenceTimeoutMs = 2000;
	}

	class NetworkStateEndToEndTest : public test::CallTest {
	protected:
	class UnusedTransport : public Transport {
	private:
	bool SendRtp(const uint8_t* packet,
	size_t length,
	const PacketOptions& options) override {
	ADD_FAILURE() << "Unexpected RTP sent.";
	return false;
	}

	bool SendRtcp(const uint8_t* packet, size_t length) override {
	ADD_FAILURE() << "Unexpected RTCP sent.";
	return false;
	}
	};
	class RequiredTransport : public Transport {
	public:
	RequiredTransport(bool rtp_required, bool rtcp_required)
	: need_rtp_(rtp_required), need_rtcp_(rtcp_required) {}
	~RequiredTransport() {
	if (need_rtp_) {
	ADD_FAILURE() << "Expected RTP packet not sent.";
	}
	if (need_rtcp_) {
	ADD_FAILURE() << "Expected RTCP packet not sent.";
	}
	}

	private:
	bool SendRtp(const uint8_t* packet,
	size_t length,
	const PacketOptions& options) override {
	MutexLock lock(&mutex_);
	need_rtp_ = false;
	return true;
	}

	bool SendRtcp(const uint8_t* packet, size_t length) override {
	MutexLock lock(&mutex_);
	need_rtcp_ = false;
	return true;
	}
	bool need_rtp_;
	bool need_rtcp_;
	Mutex mutex_;
	};
	void VerifyNewVideoSendStreamsRespectNetworkState(
	MediaType network_to_bring_up,
	VideoEncoder* encoder,
	Transport* transport);
	void VerifyNewVideoReceiveStreamsRespectNetworkState(
	MediaType network_to_bring_up,
	Transport* transport);
	};

	void NetworkStateEndToEndTest::VerifyNewVideoSendStreamsRespectNetworkState(
	MediaType network_to_bring_up,
	VideoEncoder* encoder,
	Transport* transport) {
	test::VideoEncoderProxyFactory encoder_factory(encoder);

	SendTask(task_queue(), [this, network_to_bring_up, &encoder_factory,
	transport]() {
	CreateSenderCall(Call::Config(send_event_log_.get()));
	sender_call_->SignalChannelNetworkState(network_to_bring_up, kNetworkUp);

	CreateSendConfig(1, 0, 0, transport);
	GetVideoSendConfig()->encoder_settings.encoder_factory = &encoder_factory;
	CreateVideoStreams();
	CreateFrameGeneratorCapturer(test::VideoTestConstants::kDefaultFramerate,
	test::VideoTestConstants::kDefaultWidth,
	test::VideoTestConstants::kDefaultHeight);

	Start();
	});

	SleepMs(kSilenceTimeoutMs);

	SendTask(task_queue(), [this]() {
	Stop();
	DestroyStreams();
	DestroyCalls();
	});
	}

	void NetworkStateEndToEndTest::VerifyNewVideoReceiveStreamsRespectNetworkState(
	MediaType network_to_bring_up,
	Transport* transport) {
	SendTask(task_queue(), [this, network_to_bring_up, transport]() {
	CreateCalls();
	receiver_call_->SignalChannelNetworkState(network_to_bring_up, kNetworkUp);
	CreateSendTransport(BuiltInNetworkBehaviorConfig(),
	/observer=/nullptr);

	CreateSendConfig(1, 0, 0);
	CreateMatchingReceiveConfigs(transport);
	CreateVideoStreams();
	CreateFrameGeneratorCapturer(test::VideoTestConstants::kDefaultFramerate,
	test::VideoTestConstants::kDefaultWidth,
	test::VideoTestConstants::kDefaultHeight);
	Start();
	});

	SleepMs(kSilenceTimeoutMs);

	SendTask(task_queue(), [this]() {
	Stop();
	DestroyStreams();
	DestroyCalls();
	});
	}

	TEST_F(NetworkStateEndToEndTest, RespectsNetworkState) {
	// TODO(pbos): Remove accepted downtime packets etc. when signaling network
	// down blocks until no more packets will be sent.

	// Pacer will send from its packet list and then send required padding before
	// checking paused_ again. This should be enough for one round of pacing,
	// otherwise increase.
	static const int kNumAcceptedDowntimeRtp = 5;
	// A single RTCP may be in the pipeline.
	static const int kNumAcceptedDowntimeRtcp = 1;
	class NetworkStateTest : public test::EndToEndTest, public test::FakeEncoder {
	public:
	explicit NetworkStateTest(TaskQueueBase* task_queue)
	: EndToEndTest(test::VideoTestConstants::kDefaultTimeout),
	FakeEncoder(Clock::GetRealTimeClock()),
	e2e_test_task_queue_(task_queue),
	task_queue_(CreateDefaultTaskQueueFactory()->CreateTaskQueue(
	"NetworkStateTest",
	TaskQueueFactory::Priority::NORMAL)),
	sender_call_(nullptr),
	receiver_call_(nullptr),
	encoder_factory_(this),
	sender_state_(kNetworkUp),
	sender_rtp_(0),
	sender_padding_(0),
	sender_rtcp_(0),
	receiver_rtcp_(0),
	down_frames_(0) {}

	Action OnSendRtp(const uint8_t* packet, size_t length) override {
	MutexLock lock(&test_mutex_);
	RtpPacket rtp_packet;
	EXPECT_TRUE(rtp_packet.Parse(packet, length));
	if (rtp_packet.payload_size() == 0)
	++sender_padding_;
	++sender_rtp_;
	packet_event_.Set();
	return SEND_PACKET;
	}

	Action OnSendRtcp(const uint8_t* packet, size_t length) override {
	MutexLock lock(&test_mutex_);
	++sender_rtcp_;
	packet_event_.Set();
	return SEND_PACKET;
	}

	Action OnReceiveRtp(const uint8_t* packet, size_t length) override {
	ADD_FAILURE() << "Unexpected receiver RTP, should not be sending.";
	return SEND_PACKET;
	}

	Action OnReceiveRtcp(const uint8_t* packet, size_t length) override {
	MutexLock lock(&test_mutex_);
	++receiver_rtcp_;
	packet_event_.Set();
	return SEND_PACKET;
	}

	void OnCallsCreated(Call* sender_call, Call* receiver_call) override {
	sender_call_ = sender_call;
	receiver_call_ = receiver_call;
	}

	void ModifyVideoConfigs(
	VideoSendStream::Config* send_config,
	std::vector<VideoReceiveStreamInterface::Config>* receive_configs,
	VideoEncoderConfig* encoder_config) override {
	send_config->encoder_settings.encoder_factory = &encoder_factory_;
	}

	void SignalChannelNetworkState(Call* call,
	MediaType media_type,
	NetworkState network_state) {
	SendTask(e2e_test_task_queue_, [call, media_type, network_state] {
	call->SignalChannelNetworkState(media_type, network_state);
	});
	}

	void PerformTest() override {
	EXPECT_TRUE(
	encoded_frames_.Wait(test::VideoTestConstants::kDefaultTimeout))
	<< "No frames received by the encoder.";

	SendTask(task_queue_.get(), [this]() {
	// Wait for packets from both sender/receiver.
	WaitForPacketsOrSilence(false, false);

	// Sender-side network down for audio; there should be no effect on
	// video
	SignalChannelNetworkState(sender_call_, MediaType::AUDIO, kNetworkDown);

	WaitForPacketsOrSilence(false, false);

	// Receiver-side network down for audio; no change expected
	SignalChannelNetworkState(receiver_call_, MediaType::AUDIO,
	kNetworkDown);
	WaitForPacketsOrSilence(false, false);

	// Sender-side network down.
	SignalChannelNetworkState(sender_call_, MediaType::VIDEO, kNetworkDown);
	{
	MutexLock lock(&test_mutex_);
	// After network goes down we shouldn't be encoding more frames.
	sender_state_ = kNetworkDown;
	}
	// Wait for receiver-packets and no sender packets.
	WaitForPacketsOrSilence(true, false);

	// Receiver-side network down.
	SignalChannelNetworkState(receiver_call_, MediaType::VIDEO,
	kNetworkDown);
	WaitForPacketsOrSilence(true, true);

	// Network up for audio for both sides; video is still not expected to
	// start
	SignalChannelNetworkState(sender_call_, MediaType::AUDIO, kNetworkUp);
	SignalChannelNetworkState(receiver_call_, MediaType::AUDIO, kNetworkUp);
	WaitForPacketsOrSilence(true, true);

	// Network back up again for both.
	{
	MutexLock lock(&test_mutex_);
	// It's OK to encode frames again, as we're about to bring up the
	// network.
	sender_state_ = kNetworkUp;
	}
	SignalChannelNetworkState(sender_call_, MediaType::VIDEO, kNetworkUp);
	SignalChannelNetworkState(receiver_call_, MediaType::VIDEO, kNetworkUp);
	WaitForPacketsOrSilence(false, false);

	// TODO(skvlad): add tests to verify that the audio streams are stopped
	// when the network goes down for audio once the workaround in
	// paced_sender.cc is removed.
	});
	}

	int32_t Encode(const VideoFrame& input_image,
	const std::vector<VideoFrameType>* frame_types) override {
	{
	MutexLock lock(&test_mutex_);
	if (sender_state_ == kNetworkDown) {
	++down_frames_;
	EXPECT_LE(down_frames_, 1)
	<< "Encoding more than one frame while network is down.";
	if (down_frames_ > 1)
	encoded_frames_.Set();
	} else {
	encoded_frames_.Set();
	}
	}
	return test::FakeEncoder::Encode(input_image, frame_types);
	}

	private:
	void WaitForPacketsOrSilence(bool sender_down, bool receiver_down) {
	int64_t initial_time_ms = clock_->TimeInMilliseconds();
	int initial_sender_rtp;
	int initial_sender_rtcp;
	int initial_receiver_rtcp;
	{
	MutexLock lock(&test_mutex_);
	initial_sender_rtp = sender_rtp_;
	initial_sender_rtcp = sender_rtcp_;
	initial_receiver_rtcp = receiver_rtcp_;
	}
	bool sender_done = false;
	bool receiver_done = false;
	while (!sender_done \|\| !receiver_done) {
	packet_event_.Wait(TimeDelta::Millis(kSilenceTimeoutMs));
	int64_t time_now_ms = clock_->TimeInMilliseconds();
	MutexLock lock(&test_mutex_);
	if (sender_down) {
	ASSERT_LE(sender_rtp_ - initial_sender_rtp - sender_padding_,
	kNumAcceptedDowntimeRtp)
	<< "RTP sent during sender-side downtime.";
	ASSERT_LE(sender_rtcp_ - initial_sender_rtcp,
	kNumAcceptedDowntimeRtcp)
	<< "RTCP sent during sender-side downtime.";
	if (time_now_ms - initial_time_ms >=
	static_cast<int64_t>(kSilenceTimeoutMs)) {
	sender_done = true;
	}
	} else {
	if (sender_rtp_ > initial_sender_rtp + kNumAcceptedDowntimeRtp)
	sender_done = true;
	}
	if (receiver_down) {
	ASSERT_LE(receiver_rtcp_ - initial_receiver_rtcp,
	kNumAcceptedDowntimeRtcp)
	<< "RTCP sent during receiver-side downtime.";
	if (time_now_ms - initial_time_ms >=
	static_cast<int64_t>(kSilenceTimeoutMs)) {
	receiver_done = true;
	}
	} else {
	if (receiver_rtcp_ > initial_receiver_rtcp + kNumAcceptedDowntimeRtcp)
	receiver_done = true;
	}
	}
	}

	TaskQueueBase* const e2e_test_task_queue_;
	std::unique_ptr<TaskQueueBase, TaskQueueDeleter> task_queue_;
	Mutex test_mutex_;
	rtc::Event encoded_frames_;
	rtc::Event packet_event_;
	Call* sender_call_;
	Call* receiver_call_;
	test::VideoEncoderProxyFactory encoder_factory_;
	NetworkState sender_state_ RTC_GUARDED_BY(test_mutex_);
	int sender_rtp_ RTC_GUARDED_BY(test_mutex_);
	int sender_padding_ RTC_GUARDED_BY(test_mutex_);
	int sender_rtcp_ RTC_GUARDED_BY(test_mutex_);
	int receiver_rtcp_ RTC_GUARDED_BY(test_mutex_);
	int down_frames_ RTC_GUARDED_BY(test_mutex_);
	} test(task_queue());

	RunBaseTest(&test);
	}

	TEST_F(NetworkStateEndToEndTest, NewVideoSendStreamsRespectVideoNetworkDown) {
	class UnusedEncoder : public test::FakeEncoder {
	public:
	UnusedEncoder() : FakeEncoder(Clock::GetRealTimeClock()) {}

	int32_t InitEncode(const VideoCodec* config,
	const Settings& settings) override {
	EXPECT_GT(config->startBitrate, 0u);
	return 0;
	}
	int32_t Encode(const VideoFrame& input_image,
	const std::vector<VideoFrameType>* frame_types) override {
	ADD_FAILURE() << "Unexpected frame encode.";
	return test::FakeEncoder::Encode(input_image, frame_types);
	}
	};

	UnusedEncoder unused_encoder;
	UnusedTransport unused_transport;
	VerifyNewVideoSendStreamsRespectNetworkState(
	MediaType::AUDIO, &unused_encoder, &unused_transport);
	}

	TEST_F(NetworkStateEndToEndTest, NewVideoSendStreamsIgnoreAudioNetworkDown) {
	class RequiredEncoder : public test::FakeEncoder {
	public:
	RequiredEncoder()
	: FakeEncoder(Clock::GetRealTimeClock()), encoded_frame_(false) {}
	~RequiredEncoder() {
	if (!encoded_frame_) {
	ADD_FAILURE() << "Didn't encode an expected frame";
	}
	}
	int32_t Encode(const VideoFrame& input_image,
	const std::vector<VideoFrameType>* frame_types) override {
	encoded_frame_ = true;
	return test::FakeEncoder::Encode(input_image, frame_types);
	}

	private:
	bool encoded_frame_;
	};

	RequiredTransport required_transport(true /rtp/, false /rtcp/);
	RequiredEncoder required_encoder;
	VerifyNewVideoSendStreamsRespectNetworkState(
	MediaType::VIDEO, &required_encoder, &required_transport);
	}

	TEST_F(NetworkStateEndToEndTest,
	NewVideoReceiveStreamsRespectVideoNetworkDown) {
	UnusedTransport transport;
	VerifyNewVideoReceiveStreamsRespectNetworkState(MediaType::AUDIO, &transport);
	}

	TEST_F(NetworkStateEndToEndTest, NewVideoReceiveStreamsIgnoreAudioNetworkDown) {
	RequiredTransport transport(false /rtp/, true /rtcp/);
	VerifyNewVideoReceiveStreamsRespectNetworkState(MediaType::VIDEO, &transport);
	}

	} // namespace webrtc