webrtc/modules/congestion_controller/congestion_controller.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.
  */

 #include "webrtc/modules/congestion_controller/include/congestion_controller.h"

 #include <algorithm>
 #include <memory>
 #include <vector>

 #include "webrtc/base/checks.h"
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/rate_limiter.h"
 #include "webrtc/base/socket.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"
 #include "webrtc/modules/congestion_controller/probe_controller.h"
 #include "webrtc/modules/remote_bitrate_estimator/include/send_time_history.h"
 #include "webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_abs_send_time.h"
 #include "webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h"
 #include "webrtc/modules/utility/include/process_thread.h"
 #include "webrtc/system_wrappers/include/critical_section_wrapper.h"
 #include "webrtc/video/payload_router.h"

 namespace webrtc {
 namespace {

 static const uint32_t kTimeOffsetSwitchThreshold = 30;
 static const int64_t kRetransmitWindowSizeMs = 500;

 // Makes sure that the bitrate and the min, max values are in valid range.
 static void ClampBitrates(int* bitrate_bps,
                           int* min_bitrate_bps,
                           int* max_bitrate_bps) {
   // TODO(holmer): We should make sure the default bitrates are set to 10 kbps,
   // and that we don't try to set the min bitrate to 0 from any applications.
   // The congestion controller should allow a min bitrate of 0.
   const int kMinBitrateBps = 10000;
   if (*min_bitrate_bps < kMinBitrateBps)
     *min_bitrate_bps = kMinBitrateBps;
   if (*max_bitrate_bps > 0)
     *max_bitrate_bps = std::max(*min_bitrate_bps, *max_bitrate_bps);
   if (*bitrate_bps > 0)
     *bitrate_bps = std::max(*min_bitrate_bps, *bitrate_bps);
 }

 class WrappingBitrateEstimator : public RemoteBitrateEstimator {
  public:
   WrappingBitrateEstimator(RemoteBitrateObserver* observer, Clock* clock)
       : observer_(observer),
         clock_(clock),
         crit_sect_(CriticalSectionWrapper::CreateCriticalSection()),
         rbe_(new RemoteBitrateEstimatorSingleStream(observer_, clock_)),
         using_absolute_send_time_(false),
         packets_since_absolute_send_time_(0),
         min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps) {}

   virtual ~WrappingBitrateEstimator() {}

   void IncomingPacket(int64_t arrival_time_ms,
                       size_t payload_size,
                       const RTPHeader& header) override {
     CriticalSectionScoped cs(crit_sect_.get());
     PickEstimatorFromHeader(header);
     rbe_->IncomingPacket(arrival_time_ms, payload_size, header);
   }

   void Process() override {
     CriticalSectionScoped cs(crit_sect_.get());
     rbe_->Process();
   }

   int64_t TimeUntilNextProcess() override {
     CriticalSectionScoped cs(crit_sect_.get());
     return rbe_->TimeUntilNextProcess();
   }

   void OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) override {
     CriticalSectionScoped cs(crit_sect_.get());
     rbe_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
   }

   void RemoveStream(unsigned int ssrc) override {
     CriticalSectionScoped cs(crit_sect_.get());
     rbe_->RemoveStream(ssrc);
   }

   bool LatestEstimate(std::vector<unsigned int>* ssrcs,
                       unsigned int* bitrate_bps) const override {
     CriticalSectionScoped cs(crit_sect_.get());
     return rbe_->LatestEstimate(ssrcs, bitrate_bps);
   }

   void SetMinBitrate(int min_bitrate_bps) override {
     CriticalSectionScoped cs(crit_sect_.get());
     rbe_->SetMinBitrate(min_bitrate_bps);
     min_bitrate_bps_ = min_bitrate_bps;
   }

  private:
   void PickEstimatorFromHeader(const RTPHeader& header)
       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_.get()) {
     if (header.extension.hasAbsoluteSendTime) {
       // If we see AST in header, switch RBE strategy immediately.
       if (!using_absolute_send_time_) {
         LOG(LS_INFO) <<
             "WrappingBitrateEstimator: Switching to absolute send time RBE.";
         using_absolute_send_time_ = true;
         PickEstimator();
       }
       packets_since_absolute_send_time_ = 0;
     } else {
       // When we don't see AST, wait for a few packets before going back to TOF.
       if (using_absolute_send_time_) {
         ++packets_since_absolute_send_time_;
         if (packets_since_absolute_send_time_ >= kTimeOffsetSwitchThreshold) {
           LOG(LS_INFO) << "WrappingBitrateEstimator: Switching to transmission "
                        << "time offset RBE.";
           using_absolute_send_time_ = false;
           PickEstimator();
         }
       }
     }
   }

   // Instantiate RBE for Time Offset or Absolute Send Time extensions.
   void PickEstimator() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_.get()) {
     if (using_absolute_send_time_) {
       rbe_.reset(new RemoteBitrateEstimatorAbsSendTime(observer_, clock_));
     } else {
       rbe_.reset(new RemoteBitrateEstimatorSingleStream(observer_, clock_));
     }
     rbe_->SetMinBitrate(min_bitrate_bps_);
   }

   RemoteBitrateObserver* observer_;
   Clock* const clock_;
   std::unique_ptr<CriticalSectionWrapper> crit_sect_;
   std::unique_ptr<RemoteBitrateEstimator> rbe_;
   bool using_absolute_send_time_;
   uint32_t packets_since_absolute_send_time_;
   int min_bitrate_bps_;

   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(WrappingBitrateEstimator);
 };

 }  // namespace

 CongestionController::CongestionController(
     Clock* clock,
     Observer* observer,
     RemoteBitrateObserver* remote_bitrate_observer,
     RtcEventLog* event_log)
     : clock_(clock),
       observer_(observer),
       packet_router_(new PacketRouter()),
       pacer_(new PacedSender(clock_, packet_router_.get())),
       remote_bitrate_estimator_(
           new WrappingBitrateEstimator(remote_bitrate_observer, clock_)),
       bitrate_controller_(
           BitrateController::CreateBitrateController(clock_, event_log)),
       probe_controller_(new ProbeController(pacer_.get(), clock_)),
       retransmission_rate_limiter_(
           new RateLimiter(clock, kRetransmitWindowSizeMs)),
       remote_estimator_proxy_(clock_, packet_router_.get()),
       transport_feedback_adapter_(clock_, bitrate_controller_.get()),
       min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps),
       max_bitrate_bps_(0),
       last_reported_bitrate_bps_(0),
       last_reported_fraction_loss_(0),
       last_reported_rtt_(0),
       network_state_(kNetworkUp) {
   Init();
 }

 CongestionController::CongestionController(
     Clock* clock,
     Observer* observer,
     RemoteBitrateObserver* remote_bitrate_observer,
     RtcEventLog* event_log,
     std::unique_ptr<PacketRouter> packet_router,
     std::unique_ptr<PacedSender> pacer)
     : clock_(clock),
       observer_(observer),
       packet_router_(std::move(packet_router)),
       pacer_(std::move(pacer)),
       remote_bitrate_estimator_(
           new WrappingBitrateEstimator(remote_bitrate_observer, clock_)),
       // Constructed last as this object calls the provided callback on
       // construction.
       bitrate_controller_(
           BitrateController::CreateBitrateController(clock_, event_log)),
       probe_controller_(new ProbeController(pacer_.get(), clock_)),
       retransmission_rate_limiter_(
           new RateLimiter(clock, kRetransmitWindowSizeMs)),
       remote_estimator_proxy_(clock_, packet_router_.get()),
       transport_feedback_adapter_(clock_, bitrate_controller_.get()),
       min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps),
       max_bitrate_bps_(0),
       last_reported_bitrate_bps_(0),
       last_reported_fraction_loss_(0),
       last_reported_rtt_(0),
       network_state_(kNetworkUp) {
   Init();
 }

 CongestionController::~CongestionController() {}

 void CongestionController::Init() {
   transport_feedback_adapter_.InitBwe();
   transport_feedback_adapter_.SetMinBitrate(min_bitrate_bps_);
 }

 void CongestionController::SetBweBitrates(int min_bitrate_bps,
                                           int start_bitrate_bps,
                                           int max_bitrate_bps) {
   ClampBitrates(&start_bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
   bitrate_controller_->SetBitrates(start_bitrate_bps,
                                    min_bitrate_bps,
                                    max_bitrate_bps);

   probe_controller_->SetBitrates(min_bitrate_bps, start_bitrate_bps,
                                  max_bitrate_bps);
   max_bitrate_bps_ = max_bitrate_bps;

   if (remote_bitrate_estimator_)
     remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);
   min_bitrate_bps_ = min_bitrate_bps;
   transport_feedback_adapter_.SetMinBitrate(min_bitrate_bps_);
   MaybeTriggerOnNetworkChanged();
 }

 void CongestionController::ResetBweAndBitrates(int bitrate_bps,
                                                int min_bitrate_bps,
                                                int max_bitrate_bps) {
   ClampBitrates(&bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
   // TODO(honghaiz): Recreate this object once the bitrate controller is
   // no longer exposed outside CongestionController.
   bitrate_controller_->ResetBitrates(bitrate_bps, min_bitrate_bps,
                                      max_bitrate_bps);
   min_bitrate_bps_ = min_bitrate_bps;
   max_bitrate_bps_ = max_bitrate_bps;
   // TODO(honghaiz): Recreate this object once the remote bitrate estimator is
   // no longer exposed outside CongestionController.
   if (remote_bitrate_estimator_)
     remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);

   transport_feedback_adapter_.InitBwe();
   transport_feedback_adapter_.SetMinBitrate(min_bitrate_bps);
   // TODO(holmer): Trigger a new probe once mid-call probing is implemented.
   MaybeTriggerOnNetworkChanged();
 }

 BitrateController* CongestionController::GetBitrateController() const {
   return bitrate_controller_.get();
 }

 RemoteBitrateEstimator* CongestionController::GetRemoteBitrateEstimator(
     bool send_side_bwe) {
   if (send_side_bwe) {
     return &remote_estimator_proxy_;
   } else {
     return remote_bitrate_estimator_.get();
   }
 }

 TransportFeedbackObserver*
 CongestionController::GetTransportFeedbackObserver() {
   return &transport_feedback_adapter_;
 }

 RateLimiter* CongestionController::GetRetransmissionRateLimiter() {
   return retransmission_rate_limiter_.get();
 }

 void CongestionController::SetAllocatedSendBitrateLimits(
     int min_send_bitrate_bps,
     int max_padding_bitrate_bps) {
   pacer_->SetSendBitrateLimits(min_send_bitrate_bps, max_padding_bitrate_bps);
 }

 int64_t CongestionController::GetPacerQueuingDelayMs() const {
   return IsNetworkDown() ? 0 : pacer_->QueueInMs();
 }

 void CongestionController::SignalNetworkState(NetworkState state) {
   LOG(LS_INFO) << "SignalNetworkState "
                << (state == kNetworkUp ? "Up" : "Down");
   if (state == kNetworkUp) {
     pacer_->Resume();
   } else {
     pacer_->Pause();
   }
   {
     rtc::CritScope cs(&critsect_);
     network_state_ = state;
   }
   MaybeTriggerOnNetworkChanged();
 }

 void CongestionController::OnSentPacket(const rtc::SentPacket& sent_packet) {
   transport_feedback_adapter_.OnSentPacket(sent_packet.packet_id,
                                            sent_packet.send_time_ms);
 }

 void CongestionController::OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) {
   remote_bitrate_estimator_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
   transport_feedback_adapter_.OnRttUpdate(avg_rtt_ms, max_rtt_ms);
 }

 int64_t CongestionController::TimeUntilNextProcess() {
   return std::min(bitrate_controller_->TimeUntilNextProcess(),
                   remote_bitrate_estimator_->TimeUntilNextProcess());
 }

 void CongestionController::Process() {
   bitrate_controller_->Process();
   remote_bitrate_estimator_->Process();
   MaybeTriggerOnNetworkChanged();
 }

 void CongestionController::MaybeTriggerOnNetworkChanged() {
   // TODO(perkj): |observer_| can be nullptr if the ctor that accepts a
   // BitrateObserver is used. Remove this check once the ctor is removed.
   if (!observer_)
     return;

   uint32_t bitrate_bps;
   uint8_t fraction_loss;
   int64_t rtt;
   bool estimate_changed = bitrate_controller_->GetNetworkParameters(
       &bitrate_bps, &fraction_loss, &rtt);
   if (estimate_changed) {
     pacer_->SetEstimatedBitrate(bitrate_bps);
     probe_controller_->SetEstimatedBitrate(bitrate_bps);
     retransmission_rate_limiter_->SetMaxRate(bitrate_bps);
   }

   bitrate_bps = IsNetworkDown() || IsSendQueueFull() ? 0 : bitrate_bps;

   if (HasNetworkParametersToReportChanged(bitrate_bps, fraction_loss, rtt)) {
     observer_->OnNetworkChanged(bitrate_bps, fraction_loss, rtt);
   }
 }

 bool CongestionController::HasNetworkParametersToReportChanged(
     uint32_t bitrate_bps,
     uint8_t fraction_loss,
     int64_t rtt) {
   rtc::CritScope cs(&critsect_);
   bool changed =
       last_reported_bitrate_bps_ != bitrate_bps ||
       (bitrate_bps > 0 && (last_reported_fraction_loss_ != fraction_loss ||
                            last_reported_rtt_ != rtt));
   if (changed && (last_reported_bitrate_bps_ == 0 || bitrate_bps == 0)) {
     LOG(LS_INFO) << "Bitrate estimate state changed, BWE: " << bitrate_bps
                  << " bps.";
   }
   last_reported_bitrate_bps_ = bitrate_bps;
   last_reported_fraction_loss_ = fraction_loss;
   last_reported_rtt_ = rtt;
   return changed;
 }

 bool CongestionController::IsSendQueueFull() const {
   return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
 }

 bool CongestionController::IsNetworkDown() const {
   rtc::CritScope cs(&critsect_);
   return network_state_ == kNetworkDown;
 }

 }  // 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.
	*/

	#include "webrtc/modules/congestion_controller/include/congestion_controller.h"

	#include <algorithm>
	#include <memory>
	#include <vector>

	#include "webrtc/base/checks.h"
	#include "webrtc/base/constructormagic.h"
	#include "webrtc/base/logging.h"
	#include "webrtc/base/rate_limiter.h"
	#include "webrtc/base/socket.h"
	#include "webrtc/base/thread_annotations.h"
	#include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"
	#include "webrtc/modules/congestion_controller/probe_controller.h"
	#include "webrtc/modules/remote_bitrate_estimator/include/send_time_history.h"
	#include "webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_abs_send_time.h"
	#include "webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h"
	#include "webrtc/modules/utility/include/process_thread.h"
	#include "webrtc/system_wrappers/include/critical_section_wrapper.h"
	#include "webrtc/video/payload_router.h"

	namespace webrtc {
	namespace {

	static const uint32_t kTimeOffsetSwitchThreshold = 30;
	static const int64_t kRetransmitWindowSizeMs = 500;

	// Makes sure that the bitrate and the min, max values are in valid range.
	static void ClampBitrates(int* bitrate_bps,
	int* min_bitrate_bps,
	int* max_bitrate_bps) {
	// TODO(holmer): We should make sure the default bitrates are set to 10 kbps,
	// and that we don't try to set the min bitrate to 0 from any applications.
	// The congestion controller should allow a min bitrate of 0.
	const int kMinBitrateBps = 10000;
	if (*min_bitrate_bps < kMinBitrateBps)
	*min_bitrate_bps = kMinBitrateBps;
	if (*max_bitrate_bps > 0)
	max_bitrate_bps = std::max(min_bitrate_bps, *max_bitrate_bps);
	if (*bitrate_bps > 0)
	bitrate_bps = std::max(min_bitrate_bps, *bitrate_bps);
	}

	class WrappingBitrateEstimator : public RemoteBitrateEstimator {
	public:
	WrappingBitrateEstimator(RemoteBitrateObserver* observer, Clock* clock)
	: observer_(observer),
	clock_(clock),
	crit_sect_(CriticalSectionWrapper::CreateCriticalSection()),
	rbe_(new RemoteBitrateEstimatorSingleStream(observer_, clock_)),
	using_absolute_send_time_(false),
	packets_since_absolute_send_time_(0),
	min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps) {}

	virtual ~WrappingBitrateEstimator() {}

	void IncomingPacket(int64_t arrival_time_ms,
	size_t payload_size,
	const RTPHeader& header) override {
	CriticalSectionScoped cs(crit_sect_.get());
	PickEstimatorFromHeader(header);
	rbe_->IncomingPacket(arrival_time_ms, payload_size, header);
	}

	void Process() override {
	CriticalSectionScoped cs(crit_sect_.get());
	rbe_->Process();
	}

	int64_t TimeUntilNextProcess() override {
	CriticalSectionScoped cs(crit_sect_.get());
	return rbe_->TimeUntilNextProcess();
	}

	void OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) override {
	CriticalSectionScoped cs(crit_sect_.get());
	rbe_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
	}

	void RemoveStream(unsigned int ssrc) override {
	CriticalSectionScoped cs(crit_sect_.get());
	rbe_->RemoveStream(ssrc);
	}

	bool LatestEstimate(std::vector<unsigned int>* ssrcs,
	unsigned int* bitrate_bps) const override {
	CriticalSectionScoped cs(crit_sect_.get());
	return rbe_->LatestEstimate(ssrcs, bitrate_bps);
	}

	void SetMinBitrate(int min_bitrate_bps) override {
	CriticalSectionScoped cs(crit_sect_.get());
	rbe_->SetMinBitrate(min_bitrate_bps);
	min_bitrate_bps_ = min_bitrate_bps;
	}

	private:
	void PickEstimatorFromHeader(const RTPHeader& header)
	EXCLUSIVE_LOCKS_REQUIRED(crit_sect_.get()) {
	if (header.extension.hasAbsoluteSendTime) {
	// If we see AST in header, switch RBE strategy immediately.
	if (!using_absolute_send_time_) {
	LOG(LS_INFO) <<
	"WrappingBitrateEstimator: Switching to absolute send time RBE.";
	using_absolute_send_time_ = true;
	PickEstimator();
	}
	packets_since_absolute_send_time_ = 0;
	} else {
	// When we don't see AST, wait for a few packets before going back to TOF.
	if (using_absolute_send_time_) {
	++packets_since_absolute_send_time_;
	if (packets_since_absolute_send_time_ >= kTimeOffsetSwitchThreshold) {
	LOG(LS_INFO) << "WrappingBitrateEstimator: Switching to transmission "
	<< "time offset RBE.";
	using_absolute_send_time_ = false;
	PickEstimator();
	}
	}
	}
	}

	// Instantiate RBE for Time Offset or Absolute Send Time extensions.
	void PickEstimator() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_.get()) {
	if (using_absolute_send_time_) {
	rbe_.reset(new RemoteBitrateEstimatorAbsSendTime(observer_, clock_));
	} else {
	rbe_.reset(new RemoteBitrateEstimatorSingleStream(observer_, clock_));
	}
	rbe_->SetMinBitrate(min_bitrate_bps_);
	}

	RemoteBitrateObserver* observer_;
	Clock* const clock_;
	std::unique_ptr<CriticalSectionWrapper> crit_sect_;
	std::unique_ptr<RemoteBitrateEstimator> rbe_;
	bool using_absolute_send_time_;
	uint32_t packets_since_absolute_send_time_;
	int min_bitrate_bps_;

	RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(WrappingBitrateEstimator);
	};

	} // namespace

	CongestionController::CongestionController(
	Clock* clock,
	Observer* observer,
	RemoteBitrateObserver* remote_bitrate_observer,
	RtcEventLog* event_log)
	: clock_(clock),
	observer_(observer),
	packet_router_(new PacketRouter()),
	pacer_(new PacedSender(clock_, packet_router_.get())),
	remote_bitrate_estimator_(
	new WrappingBitrateEstimator(remote_bitrate_observer, clock_)),
	bitrate_controller_(
	BitrateController::CreateBitrateController(clock_, event_log)),
	probe_controller_(new ProbeController(pacer_.get(), clock_)),
	retransmission_rate_limiter_(
	new RateLimiter(clock, kRetransmitWindowSizeMs)),
	remote_estimator_proxy_(clock_, packet_router_.get()),
	transport_feedback_adapter_(clock_, bitrate_controller_.get()),
	min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps),
	max_bitrate_bps_(0),
	last_reported_bitrate_bps_(0),
	last_reported_fraction_loss_(0),
	last_reported_rtt_(0),
	network_state_(kNetworkUp) {
	Init();
	}

	CongestionController::CongestionController(
	Clock* clock,
	Observer* observer,
	RemoteBitrateObserver* remote_bitrate_observer,
	RtcEventLog* event_log,
	std::unique_ptr<PacketRouter> packet_router,
	std::unique_ptr<PacedSender> pacer)
	: clock_(clock),
	observer_(observer),
	packet_router_(std::move(packet_router)),
	pacer_(std::move(pacer)),
	remote_bitrate_estimator_(
	new WrappingBitrateEstimator(remote_bitrate_observer, clock_)),
	// Constructed last as this object calls the provided callback on
	// construction.
	bitrate_controller_(
	BitrateController::CreateBitrateController(clock_, event_log)),
	probe_controller_(new ProbeController(pacer_.get(), clock_)),
	retransmission_rate_limiter_(
	new RateLimiter(clock, kRetransmitWindowSizeMs)),
	remote_estimator_proxy_(clock_, packet_router_.get()),
	transport_feedback_adapter_(clock_, bitrate_controller_.get()),
	min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps),
	max_bitrate_bps_(0),
	last_reported_bitrate_bps_(0),
	last_reported_fraction_loss_(0),
	last_reported_rtt_(0),
	network_state_(kNetworkUp) {
	Init();
	}

	CongestionController::~CongestionController() {}

	void CongestionController::Init() {
	transport_feedback_adapter_.InitBwe();
	transport_feedback_adapter_.SetMinBitrate(min_bitrate_bps_);
	}

	void CongestionController::SetBweBitrates(int min_bitrate_bps,
	int start_bitrate_bps,
	int max_bitrate_bps) {
	ClampBitrates(&start_bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
	bitrate_controller_->SetBitrates(start_bitrate_bps,
	min_bitrate_bps,
	max_bitrate_bps);

	probe_controller_->SetBitrates(min_bitrate_bps, start_bitrate_bps,
	max_bitrate_bps);
	max_bitrate_bps_ = max_bitrate_bps;

	if (remote_bitrate_estimator_)
	remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);
	min_bitrate_bps_ = min_bitrate_bps;
	transport_feedback_adapter_.SetMinBitrate(min_bitrate_bps_);
	MaybeTriggerOnNetworkChanged();
	}

	void CongestionController::ResetBweAndBitrates(int bitrate_bps,
	int min_bitrate_bps,
	int max_bitrate_bps) {
	ClampBitrates(&bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
	// TODO(honghaiz): Recreate this object once the bitrate controller is
	// no longer exposed outside CongestionController.
	bitrate_controller_->ResetBitrates(bitrate_bps, min_bitrate_bps,
	max_bitrate_bps);
	min_bitrate_bps_ = min_bitrate_bps;
	max_bitrate_bps_ = max_bitrate_bps;
	// TODO(honghaiz): Recreate this object once the remote bitrate estimator is
	// no longer exposed outside CongestionController.
	if (remote_bitrate_estimator_)
	remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);

	transport_feedback_adapter_.InitBwe();
	transport_feedback_adapter_.SetMinBitrate(min_bitrate_bps);
	// TODO(holmer): Trigger a new probe once mid-call probing is implemented.
	MaybeTriggerOnNetworkChanged();
	}

	BitrateController* CongestionController::GetBitrateController() const {
	return bitrate_controller_.get();
	}

	RemoteBitrateEstimator* CongestionController::GetRemoteBitrateEstimator(
	bool send_side_bwe) {
	if (send_side_bwe) {
	return &remote_estimator_proxy_;
	} else {
	return remote_bitrate_estimator_.get();
	}
	}

	TransportFeedbackObserver*
	CongestionController::GetTransportFeedbackObserver() {
	return &transport_feedback_adapter_;
	}

	RateLimiter* CongestionController::GetRetransmissionRateLimiter() {
	return retransmission_rate_limiter_.get();
	}

	void CongestionController::SetAllocatedSendBitrateLimits(
	int min_send_bitrate_bps,
	int max_padding_bitrate_bps) {
	pacer_->SetSendBitrateLimits(min_send_bitrate_bps, max_padding_bitrate_bps);
	}

	int64_t CongestionController::GetPacerQueuingDelayMs() const {
	return IsNetworkDown() ? 0 : pacer_->QueueInMs();
	}

	void CongestionController::SignalNetworkState(NetworkState state) {
	LOG(LS_INFO) << "SignalNetworkState "
	<< (state == kNetworkUp ? "Up" : "Down");
	if (state == kNetworkUp) {
	pacer_->Resume();
	} else {
	pacer_->Pause();
	}
	{
	rtc::CritScope cs(&critsect_);
	network_state_ = state;
	}
	MaybeTriggerOnNetworkChanged();
	}

	void CongestionController::OnSentPacket(const rtc::SentPacket& sent_packet) {
	transport_feedback_adapter_.OnSentPacket(sent_packet.packet_id,
	sent_packet.send_time_ms);
	}

	void CongestionController::OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) {
	remote_bitrate_estimator_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
	transport_feedback_adapter_.OnRttUpdate(avg_rtt_ms, max_rtt_ms);
	}

	int64_t CongestionController::TimeUntilNextProcess() {
	return std::min(bitrate_controller_->TimeUntilNextProcess(),
	remote_bitrate_estimator_->TimeUntilNextProcess());
	}

	void CongestionController::Process() {
	bitrate_controller_->Process();
	remote_bitrate_estimator_->Process();
	MaybeTriggerOnNetworkChanged();
	}

	void CongestionController::MaybeTriggerOnNetworkChanged() {
	// TODO(perkj): \|observer_\| can be nullptr if the ctor that accepts a
	// BitrateObserver is used. Remove this check once the ctor is removed.
	if (!observer_)
	return;

	uint32_t bitrate_bps;
	uint8_t fraction_loss;
	int64_t rtt;
	bool estimate_changed = bitrate_controller_->GetNetworkParameters(
	&bitrate_bps, &fraction_loss, &rtt);
	if (estimate_changed) {
	pacer_->SetEstimatedBitrate(bitrate_bps);
	probe_controller_->SetEstimatedBitrate(bitrate_bps);
	retransmission_rate_limiter_->SetMaxRate(bitrate_bps);
	}

	bitrate_bps = IsNetworkDown() \|\| IsSendQueueFull() ? 0 : bitrate_bps;

	if (HasNetworkParametersToReportChanged(bitrate_bps, fraction_loss, rtt)) {
	observer_->OnNetworkChanged(bitrate_bps, fraction_loss, rtt);
	}
	}

	bool CongestionController::HasNetworkParametersToReportChanged(
	uint32_t bitrate_bps,
	uint8_t fraction_loss,
	int64_t rtt) {
	rtc::CritScope cs(&critsect_);
	bool changed =
	last_reported_bitrate_bps_ != bitrate_bps \|\|
	(bitrate_bps > 0 && (last_reported_fraction_loss_ != fraction_loss \|\|
	last_reported_rtt_ != rtt));
	if (changed && (last_reported_bitrate_bps_ == 0 \|\| bitrate_bps == 0)) {
	LOG(LS_INFO) << "Bitrate estimate state changed, BWE: " << bitrate_bps
	<< " bps.";
	}
	last_reported_bitrate_bps_ = bitrate_bps;
	last_reported_fraction_loss_ = fraction_loss;
	last_reported_rtt_ = rtt;
	return changed;
	}

	bool CongestionController::IsSendQueueFull() const {
	return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
	}

	bool CongestionController::IsNetworkDown() const {
	rtc::CritScope cs(&critsect_);
	return network_state_ == kNetworkDown;
	}

	} // namespace webrtc