webrtc/modules/congestion_controller/send_side_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/send_side_congestion_controller.h"

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

 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/rate_limiter.h"
 #include "webrtc/base/socket.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/bwe_defines.h"

 namespace webrtc {
 namespace {

 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.
   if (*min_bitrate_bps < congestion_controller::GetMinBitrateBps())
     *min_bitrate_bps = congestion_controller::GetMinBitrateBps();
   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);
 }

 }  // namespace

 SendSideCongestionController::SendSideCongestionController(
     const Clock* clock,
     Observer* observer,
     RtcEventLog* event_log,
     PacketRouter* packet_router)
     : SendSideCongestionController(
           clock,
           observer,
           event_log,
           std::unique_ptr<PacedSender>(
               new PacedSender(clock, packet_router, event_log))) {}

 SendSideCongestionController::SendSideCongestionController(
     const Clock* clock,
     Observer* observer,
     RtcEventLog* event_log,
     std::unique_ptr<PacedSender> pacer)
     : clock_(clock),
       observer_(observer),
       event_log_(event_log),
       pacer_(std::move(pacer)),
       bitrate_controller_(
           BitrateController::CreateBitrateController(clock_, event_log)),
       probe_controller_(new ProbeController(pacer_.get(), clock_)),
       retransmission_rate_limiter_(
           new RateLimiter(clock, kRetransmitWindowSizeMs)),
       transport_feedback_adapter_(clock_),
       last_reported_bitrate_bps_(0),
       last_reported_fraction_loss_(0),
       last_reported_rtt_(0),
       network_state_(kNetworkUp),
       min_bitrate_bps_(congestion_controller::GetMinBitrateBps()),
       delay_based_bwe_(new DelayBasedBwe(event_log_, clock_)) {
   delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
   worker_thread_checker_.DetachFromThread();
 }

 SendSideCongestionController::~SendSideCongestionController() {}

 void SendSideCongestionController::RegisterPacketFeedbackObserver(
     PacketFeedbackObserver* observer) {
   transport_feedback_adapter_.RegisterPacketFeedbackObserver(observer);
 }

 void SendSideCongestionController::DeRegisterPacketFeedbackObserver(
     PacketFeedbackObserver* observer) {
   transport_feedback_adapter_.DeRegisterPacketFeedbackObserver(observer);
 }

 void SendSideCongestionController::RegisterNetworkObserver(Observer* observer) {
   rtc::CritScope cs(&observer_lock_);
   RTC_DCHECK(observer_ == nullptr);
   observer_ = observer;
 }

 void SendSideCongestionController::DeRegisterNetworkObserver(
     Observer* observer) {
   rtc::CritScope cs(&observer_lock_);
   RTC_DCHECK_EQ(observer_, observer);
   observer_ = nullptr;
 }

 void SendSideCongestionController::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);

   {
     rtc::CritScope cs(&bwe_lock_);
     if (start_bitrate_bps > 0)
       delay_based_bwe_->SetStartBitrate(start_bitrate_bps);
     min_bitrate_bps_ = min_bitrate_bps;
     delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
   }
   MaybeTriggerOnNetworkChanged();
 }

 // TODO(holmer): Split this up and use SetBweBitrates in combination with
 // OnNetworkRouteChanged.
 void SendSideCongestionController::OnNetworkRouteChanged(
     const rtc::NetworkRoute& network_route,
     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 SendSideCongestionController.
   bitrate_controller_->ResetBitrates(bitrate_bps, min_bitrate_bps,
                                      max_bitrate_bps);

   transport_feedback_adapter_.SetNetworkIds(network_route.local_network_id,
                                             network_route.remote_network_id);
   {
     rtc::CritScope cs(&bwe_lock_);
     min_bitrate_bps_ = min_bitrate_bps;
     delay_based_bwe_.reset(new DelayBasedBwe(event_log_, clock_));
     delay_based_bwe_->SetStartBitrate(bitrate_bps);
     delay_based_bwe_->SetMinBitrate(min_bitrate_bps);
   }

   probe_controller_->Reset();
   probe_controller_->SetBitrates(min_bitrate_bps, bitrate_bps, max_bitrate_bps);

   MaybeTriggerOnNetworkChanged();
 }

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

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

 void SendSideCongestionController::EnablePeriodicAlrProbing(bool enable) {
   probe_controller_->EnablePeriodicAlrProbing(enable);
 }

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

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

 int64_t SendSideCongestionController::GetFirstPacketTimeMs() const {
   return pacer_->FirstSentPacketTimeMs();
 }

 PacedSender* SendSideCongestionController::pacer() {
   return pacer_.get();
 }

 TransportFeedbackObserver*
 SendSideCongestionController::GetTransportFeedbackObserver() {
   return this;
 }

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

 void SendSideCongestionController::SetTransportOverhead(
     size_t transport_overhead_bytes_per_packet) {
   transport_feedback_adapter_.SetTransportOverhead(
       transport_overhead_bytes_per_packet);
 }

 void SendSideCongestionController::OnSentPacket(
     const rtc::SentPacket& sent_packet) {
   // We're not interested in packets without an id, which may be stun packets,
   // etc, sent on the same transport.
   if (sent_packet.packet_id == -1)
     return;
   transport_feedback_adapter_.OnSentPacket(sent_packet.packet_id,
                                            sent_packet.send_time_ms);
 }

 void SendSideCongestionController::OnRttUpdate(int64_t avg_rtt_ms,
                                                int64_t max_rtt_ms) {
   rtc::CritScope cs(&bwe_lock_);
   delay_based_bwe_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
 }

 int64_t SendSideCongestionController::TimeUntilNextProcess() {
   return bitrate_controller_->TimeUntilNextProcess();
 }

 void SendSideCongestionController::Process() {
   bitrate_controller_->Process();
   probe_controller_->Process();
   MaybeTriggerOnNetworkChanged();
 }

 void SendSideCongestionController::AddPacket(
     uint32_t ssrc,
     uint16_t sequence_number,
     size_t length,
     const PacedPacketInfo& pacing_info) {
   transport_feedback_adapter_.AddPacket(ssrc, sequence_number, length,
                                         pacing_info);
 }

 void SendSideCongestionController::OnTransportFeedback(
     const rtcp::TransportFeedback& feedback) {
   RTC_DCHECK(worker_thread_checker_.CalledOnValidThread());
   transport_feedback_adapter_.OnTransportFeedback(feedback);
   std::vector<PacketFeedback> feedback_vector =
       transport_feedback_adapter_.GetTransportFeedbackVector();
   DelayBasedBwe::Result result;
   {
     rtc::CritScope cs(&bwe_lock_);
     result = delay_based_bwe_->IncomingPacketFeedbackVector(feedback_vector);
   }
   if (result.updated)
     bitrate_controller_->OnDelayBasedBweResult(result);
 }

 std::vector<PacketFeedback>
 SendSideCongestionController::GetTransportFeedbackVector() const {
   RTC_DCHECK(worker_thread_checker_.CalledOnValidThread());
   return transport_feedback_adapter_.GetTransportFeedbackVector();
 }

 void SendSideCongestionController::MaybeTriggerOnNetworkChanged() {
   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)) {
     int64_t probing_interval_ms;
     {
       rtc::CritScope cs(&bwe_lock_);
       probing_interval_ms = delay_based_bwe_->GetExpectedBwePeriodMs();
     }
     {
       rtc::CritScope cs(&observer_lock_);
       if (observer_) {
         observer_->OnNetworkChanged(bitrate_bps, fraction_loss, rtt,
                                     probing_interval_ms);
       }
     }
   }
 }

 bool SendSideCongestionController::HasNetworkParametersToReportChanged(
     uint32_t bitrate_bps,
     uint8_t fraction_loss,
     int64_t rtt) {
   rtc::CritScope cs(&network_state_lock_);
   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 SendSideCongestionController::IsSendQueueFull() const {
   return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
 }

 bool SendSideCongestionController::IsNetworkDown() const {
   rtc::CritScope cs(&network_state_lock_);
   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/send_side_congestion_controller.h"

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

	#include "webrtc/base/checks.h"
	#include "webrtc/base/logging.h"
	#include "webrtc/base/rate_limiter.h"
	#include "webrtc/base/socket.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/bwe_defines.h"

	namespace webrtc {
	namespace {

	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.
	if (*min_bitrate_bps < congestion_controller::GetMinBitrateBps())
	*min_bitrate_bps = congestion_controller::GetMinBitrateBps();
	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);
	}

	} // namespace

	SendSideCongestionController::SendSideCongestionController(
	const Clock* clock,
	Observer* observer,
	RtcEventLog* event_log,
	PacketRouter* packet_router)
	: SendSideCongestionController(
	clock,
	observer,
	event_log,
	std::unique_ptr<PacedSender>(
	new PacedSender(clock, packet_router, event_log))) {}

	SendSideCongestionController::SendSideCongestionController(
	const Clock* clock,
	Observer* observer,
	RtcEventLog* event_log,
	std::unique_ptr<PacedSender> pacer)
	: clock_(clock),
	observer_(observer),
	event_log_(event_log),
	pacer_(std::move(pacer)),
	bitrate_controller_(
	BitrateController::CreateBitrateController(clock_, event_log)),
	probe_controller_(new ProbeController(pacer_.get(), clock_)),
	retransmission_rate_limiter_(
	new RateLimiter(clock, kRetransmitWindowSizeMs)),
	transport_feedback_adapter_(clock_),
	last_reported_bitrate_bps_(0),
	last_reported_fraction_loss_(0),
	last_reported_rtt_(0),
	network_state_(kNetworkUp),
	min_bitrate_bps_(congestion_controller::GetMinBitrateBps()),
	delay_based_bwe_(new DelayBasedBwe(event_log_, clock_)) {
	delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
	worker_thread_checker_.DetachFromThread();
	}

	SendSideCongestionController::~SendSideCongestionController() {}

	void SendSideCongestionController::RegisterPacketFeedbackObserver(
	PacketFeedbackObserver* observer) {
	transport_feedback_adapter_.RegisterPacketFeedbackObserver(observer);
	}

	void SendSideCongestionController::DeRegisterPacketFeedbackObserver(
	PacketFeedbackObserver* observer) {
	transport_feedback_adapter_.DeRegisterPacketFeedbackObserver(observer);
	}

	void SendSideCongestionController::RegisterNetworkObserver(Observer* observer) {
	rtc::CritScope cs(&observer_lock_);
	RTC_DCHECK(observer_ == nullptr);
	observer_ = observer;
	}

	void SendSideCongestionController::DeRegisterNetworkObserver(
	Observer* observer) {
	rtc::CritScope cs(&observer_lock_);
	RTC_DCHECK_EQ(observer_, observer);
	observer_ = nullptr;
	}

	void SendSideCongestionController::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);

	{
	rtc::CritScope cs(&bwe_lock_);
	if (start_bitrate_bps > 0)
	delay_based_bwe_->SetStartBitrate(start_bitrate_bps);
	min_bitrate_bps_ = min_bitrate_bps;
	delay_based_bwe_->SetMinBitrate(min_bitrate_bps_);
	}
	MaybeTriggerOnNetworkChanged();
	}

	// TODO(holmer): Split this up and use SetBweBitrates in combination with
	// OnNetworkRouteChanged.
	void SendSideCongestionController::OnNetworkRouteChanged(
	const rtc::NetworkRoute& network_route,
	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 SendSideCongestionController.
	bitrate_controller_->ResetBitrates(bitrate_bps, min_bitrate_bps,
	max_bitrate_bps);

	transport_feedback_adapter_.SetNetworkIds(network_route.local_network_id,
	network_route.remote_network_id);
	{
	rtc::CritScope cs(&bwe_lock_);
	min_bitrate_bps_ = min_bitrate_bps;
	delay_based_bwe_.reset(new DelayBasedBwe(event_log_, clock_));
	delay_based_bwe_->SetStartBitrate(bitrate_bps);
	delay_based_bwe_->SetMinBitrate(min_bitrate_bps);
	}

	probe_controller_->Reset();
	probe_controller_->SetBitrates(min_bitrate_bps, bitrate_bps, max_bitrate_bps);

	MaybeTriggerOnNetworkChanged();
	}

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

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

	void SendSideCongestionController::EnablePeriodicAlrProbing(bool enable) {
	probe_controller_->EnablePeriodicAlrProbing(enable);
	}

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

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

	int64_t SendSideCongestionController::GetFirstPacketTimeMs() const {
	return pacer_->FirstSentPacketTimeMs();
	}

	PacedSender* SendSideCongestionController::pacer() {
	return pacer_.get();
	}

	TransportFeedbackObserver*
	SendSideCongestionController::GetTransportFeedbackObserver() {
	return this;
	}

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

	void SendSideCongestionController::SetTransportOverhead(
	size_t transport_overhead_bytes_per_packet) {
	transport_feedback_adapter_.SetTransportOverhead(
	transport_overhead_bytes_per_packet);
	}

	void SendSideCongestionController::OnSentPacket(
	const rtc::SentPacket& sent_packet) {
	// We're not interested in packets without an id, which may be stun packets,
	// etc, sent on the same transport.
	if (sent_packet.packet_id == -1)
	return;
	transport_feedback_adapter_.OnSentPacket(sent_packet.packet_id,
	sent_packet.send_time_ms);
	}

	void SendSideCongestionController::OnRttUpdate(int64_t avg_rtt_ms,
	int64_t max_rtt_ms) {
	rtc::CritScope cs(&bwe_lock_);
	delay_based_bwe_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
	}

	int64_t SendSideCongestionController::TimeUntilNextProcess() {
	return bitrate_controller_->TimeUntilNextProcess();
	}

	void SendSideCongestionController::Process() {
	bitrate_controller_->Process();
	probe_controller_->Process();
	MaybeTriggerOnNetworkChanged();
	}

	void SendSideCongestionController::AddPacket(
	uint32_t ssrc,
	uint16_t sequence_number,
	size_t length,
	const PacedPacketInfo& pacing_info) {
	transport_feedback_adapter_.AddPacket(ssrc, sequence_number, length,
	pacing_info);
	}

	void SendSideCongestionController::OnTransportFeedback(
	const rtcp::TransportFeedback& feedback) {
	RTC_DCHECK(worker_thread_checker_.CalledOnValidThread());
	transport_feedback_adapter_.OnTransportFeedback(feedback);
	std::vector<PacketFeedback> feedback_vector =
	transport_feedback_adapter_.GetTransportFeedbackVector();
	DelayBasedBwe::Result result;
	{
	rtc::CritScope cs(&bwe_lock_);
	result = delay_based_bwe_->IncomingPacketFeedbackVector(feedback_vector);
	}
	if (result.updated)
	bitrate_controller_->OnDelayBasedBweResult(result);
	}

	std::vector<PacketFeedback>
	SendSideCongestionController::GetTransportFeedbackVector() const {
	RTC_DCHECK(worker_thread_checker_.CalledOnValidThread());
	return transport_feedback_adapter_.GetTransportFeedbackVector();
	}

	void SendSideCongestionController::MaybeTriggerOnNetworkChanged() {
	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)) {
	int64_t probing_interval_ms;
	{
	rtc::CritScope cs(&bwe_lock_);
	probing_interval_ms = delay_based_bwe_->GetExpectedBwePeriodMs();
	}
	{
	rtc::CritScope cs(&observer_lock_);
	if (observer_) {
	observer_->OnNetworkChanged(bitrate_bps, fraction_loss, rtt,
	probing_interval_ms);
	}
	}
	}
	}

	bool SendSideCongestionController::HasNetworkParametersToReportChanged(
	uint32_t bitrate_bps,
	uint8_t fraction_loss,
	int64_t rtt) {
	rtc::CritScope cs(&network_state_lock_);
	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 SendSideCongestionController::IsSendQueueFull() const {
	return pacer_->ExpectedQueueTimeMs() > PacedSender::kMaxQueueLengthMs;
	}

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

	} // namespace webrtc