| /* |
| * Copyright (c) 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 "modules/congestion_controller/goog_cc/goog_cc_network_control.h" |
| |
| #include <inttypes.h> |
| #include <stdio.h> |
| #include <algorithm> |
| #include <cstdint> |
| #include <memory> |
| #include <numeric> |
| #include <string> |
| #include <vector> |
| |
| #include "absl/memory/memory.h" |
| #include "api/units/time_delta.h" |
| #include "modules/congestion_controller/goog_cc/acknowledged_bitrate_estimator.h" |
| #include "modules/congestion_controller/goog_cc/alr_detector.h" |
| #include "modules/congestion_controller/goog_cc/probe_controller.h" |
| #include "modules/remote_bitrate_estimator/include/bwe_defines.h" |
| #include "modules/remote_bitrate_estimator/test/bwe_test_logging.h" |
| #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/logging.h" |
| #include "system_wrappers/include/field_trial.h" |
| |
| namespace webrtc { |
| namespace { |
| |
| const char kCwndExperiment[] = "WebRTC-CwndExperiment"; |
| // When CongestionWindowPushback is enabled, the pacer is oblivious to |
| // the congestion window. The relation between outstanding data and |
| // the congestion window affects encoder allocations directly. |
| const char kCongestionPushbackExperiment[] = "WebRTC-CongestionWindowPushback"; |
| |
| const int64_t kDefaultAcceptedQueueMs = 250; |
| |
| // From RTCPSender video report interval. |
| constexpr TimeDelta kLossUpdateInterval = TimeDelta::Millis<1000>(); |
| |
| // Pacing-rate relative to our target send rate. |
| // Multiplicative factor that is applied to the target bitrate to calculate |
| // the number of bytes that can be transmitted per interval. |
| // Increasing this factor will result in lower delays in cases of bitrate |
| // overshoots from the encoder. |
| const float kDefaultPaceMultiplier = 2.5f; |
| |
| bool IsCongestionWindowPushbackExperimentEnabled() { |
| return webrtc::field_trial::IsEnabled(kCongestionPushbackExperiment) && |
| webrtc::field_trial::IsEnabled(kCwndExperiment); |
| } |
| |
| std::unique_ptr<CongestionWindowPushbackController> |
| MaybeInitalizeCongestionWindowPushbackController() { |
| return IsCongestionWindowPushbackExperimentEnabled() |
| ? absl::make_unique<CongestionWindowPushbackController>() |
| : nullptr; |
| } |
| |
| bool CwndExperimentEnabled() { |
| std::string experiment_string = |
| webrtc::field_trial::FindFullName(kCwndExperiment); |
| // The experiment is enabled iff the field trial string begins with "Enabled". |
| return experiment_string.find("Enabled") == 0; |
| } |
| bool ReadCwndExperimentParameter(int64_t* accepted_queue_ms) { |
| RTC_DCHECK(accepted_queue_ms); |
| std::string experiment_string = |
| webrtc::field_trial::FindFullName(kCwndExperiment); |
| int parsed_values = |
| sscanf(experiment_string.c_str(), "Enabled-%" PRId64, accepted_queue_ms); |
| if (parsed_values == 1) { |
| RTC_CHECK_GE(*accepted_queue_ms, 0) |
| << "Accepted must be greater than or equal to 0."; |
| return true; |
| } |
| return false; |
| } |
| |
| // Makes sure that the bitrate and the min, max values are in valid range. |
| static void ClampBitrates(int64_t* bitrate_bps, |
| int64_t* min_bitrate_bps, |
| int64_t* 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); |
| } |
| |
| std::vector<PacketFeedback> ReceivedPacketsFeedbackAsRtp( |
| const TransportPacketsFeedback report) { |
| std::vector<PacketFeedback> packet_feedback_vector; |
| for (auto& fb : report.PacketsWithFeedback()) { |
| if (fb.receive_time.IsFinite()) { |
| PacketFeedback pf(fb.receive_time.ms(), 0); |
| pf.creation_time_ms = report.feedback_time.ms(); |
| pf.payload_size = fb.sent_packet.size.bytes(); |
| pf.pacing_info = fb.sent_packet.pacing_info; |
| pf.send_time_ms = fb.sent_packet.send_time.ms(); |
| pf.unacknowledged_data = fb.sent_packet.prior_unacked_data.bytes(); |
| packet_feedback_vector.push_back(pf); |
| } |
| } |
| return packet_feedback_vector; |
| } |
| |
| int64_t GetBpsOrDefault(const absl::optional<DataRate>& rate, |
| int64_t fallback_bps) { |
| if (rate && rate->IsFinite()) { |
| return rate->bps(); |
| } else { |
| return fallback_bps; |
| } |
| } |
| |
| } // namespace |
| |
| GoogCcNetworkController::GoogCcNetworkController(RtcEventLog* event_log, |
| NetworkControllerConfig config, |
| bool feedback_only) |
| : event_log_(event_log), |
| packet_feedback_only_(feedback_only), |
| safe_reset_on_route_change_("Enabled"), |
| safe_reset_acknowledged_rate_("ack"), |
| use_stable_bandwidth_estimate_( |
| field_trial::IsEnabled("WebRTC-Bwe-StableBandwidthEstimate")), |
| fall_back_to_probe_rate_( |
| field_trial::IsEnabled("WebRTC-Bwe-ProbeRateFallback")), |
| probe_controller_(new ProbeController()), |
| congestion_window_pushback_controller_( |
| MaybeInitalizeCongestionWindowPushbackController()), |
| bandwidth_estimation_( |
| absl::make_unique<SendSideBandwidthEstimation>(event_log_)), |
| alr_detector_(absl::make_unique<AlrDetector>()), |
| probe_bitrate_estimator_(new ProbeBitrateEstimator(event_log)), |
| delay_based_bwe_(new DelayBasedBwe(event_log_)), |
| acknowledged_bitrate_estimator_( |
| absl::make_unique<AcknowledgedBitrateEstimator>()), |
| initial_config_(config), |
| last_target_rate_(*config.constraints.starting_rate), |
| pacing_factor_(config.stream_based_config.pacing_factor.value_or( |
| kDefaultPaceMultiplier)), |
| min_pacing_rate_(config.stream_based_config.min_pacing_rate.value_or( |
| DataRate::Zero())), |
| max_padding_rate_(config.stream_based_config.max_padding_rate.value_or( |
| DataRate::Zero())), |
| max_total_allocated_bitrate_(DataRate::Zero()), |
| in_cwnd_experiment_(CwndExperimentEnabled()), |
| accepted_queue_ms_(kDefaultAcceptedQueueMs) { |
| RTC_DCHECK(config.constraints.at_time.IsFinite()); |
| ParseFieldTrial( |
| {&safe_reset_on_route_change_, &safe_reset_acknowledged_rate_}, |
| field_trial::FindFullName("WebRTC-Bwe-SafeResetOnRouteChange")); |
| |
| delay_based_bwe_->SetMinBitrate(congestion_controller::GetMinBitrate()); |
| if (in_cwnd_experiment_ && |
| !ReadCwndExperimentParameter(&accepted_queue_ms_)) { |
| RTC_LOG(LS_WARNING) << "Failed to parse parameters for CwndExperiment " |
| "from field trial string. Experiment disabled."; |
| in_cwnd_experiment_ = false; |
| } |
| } |
| |
| GoogCcNetworkController::~GoogCcNetworkController() {} |
| |
| NetworkControlUpdate GoogCcNetworkController::OnNetworkAvailability( |
| NetworkAvailability msg) { |
| NetworkControlUpdate update; |
| update.probe_cluster_configs = probe_controller_->OnNetworkAvailability(msg); |
| return update; |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::OnNetworkRouteChange( |
| NetworkRouteChange msg) { |
| int64_t min_bitrate_bps = GetBpsOrDefault(msg.constraints.min_data_rate, 0); |
| int64_t max_bitrate_bps = GetBpsOrDefault(msg.constraints.max_data_rate, -1); |
| int64_t start_bitrate_bps = |
| GetBpsOrDefault(msg.constraints.starting_rate, -1); |
| |
| ClampBitrates(&start_bitrate_bps, &min_bitrate_bps, &max_bitrate_bps); |
| |
| if (safe_reset_on_route_change_) { |
| absl::optional<uint32_t> estimated_bitrate_bps; |
| if (safe_reset_acknowledged_rate_) { |
| estimated_bitrate_bps = acknowledged_bitrate_estimator_->bitrate_bps(); |
| if (!estimated_bitrate_bps) |
| estimated_bitrate_bps = acknowledged_bitrate_estimator_->PeekBps(); |
| } else { |
| int32_t target_bitrate_bps; |
| uint8_t fraction_loss; |
| int64_t rtt_ms; |
| bandwidth_estimation_->CurrentEstimate(&target_bitrate_bps, |
| &fraction_loss, &rtt_ms); |
| estimated_bitrate_bps = target_bitrate_bps; |
| } |
| if (estimated_bitrate_bps && (!msg.constraints.starting_rate || |
| estimated_bitrate_bps < start_bitrate_bps)) { |
| start_bitrate_bps = *estimated_bitrate_bps; |
| msg.constraints.starting_rate = DataRate::bps(start_bitrate_bps); |
| } |
| } |
| |
| acknowledged_bitrate_estimator_.reset(new AcknowledgedBitrateEstimator()); |
| probe_bitrate_estimator_.reset(new ProbeBitrateEstimator(event_log_)); |
| delay_based_bwe_.reset(new DelayBasedBwe(event_log_)); |
| if (msg.constraints.starting_rate) |
| delay_based_bwe_->SetStartBitrate(*msg.constraints.starting_rate); |
| // TODO(srte): Use original values instead of converted. |
| delay_based_bwe_->SetMinBitrate(DataRate::bps(min_bitrate_bps)); |
| bandwidth_estimation_->OnRouteChange(); |
| bandwidth_estimation_->SetBitrates( |
| msg.constraints.starting_rate, DataRate::bps(min_bitrate_bps), |
| msg.constraints.max_data_rate.value_or(DataRate::Infinity()), |
| msg.at_time); |
| |
| probe_controller_->Reset(msg.at_time.ms()); |
| NetworkControlUpdate update; |
| update.probe_cluster_configs = probe_controller_->SetBitrates( |
| min_bitrate_bps, start_bitrate_bps, max_bitrate_bps, msg.at_time.ms()); |
| MaybeTriggerOnNetworkChanged(&update, msg.at_time); |
| return update; |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::OnProcessInterval( |
| ProcessInterval msg) { |
| NetworkControlUpdate update; |
| if (initial_config_) { |
| update.probe_cluster_configs = |
| UpdateBitrateConstraints(initial_config_->constraints, |
| initial_config_->constraints.starting_rate); |
| update.pacer_config = GetPacingRates(msg.at_time); |
| |
| probe_controller_->EnablePeriodicAlrProbing( |
| initial_config_->stream_based_config.requests_alr_probing); |
| absl::optional<DataRate> total_bitrate = |
| initial_config_->stream_based_config.max_total_allocated_bitrate; |
| if (total_bitrate) { |
| auto probes = probe_controller_->OnMaxTotalAllocatedBitrate( |
| total_bitrate->bps(), msg.at_time.ms()); |
| update.probe_cluster_configs.insert(update.probe_cluster_configs.end(), |
| probes.begin(), probes.end()); |
| |
| max_total_allocated_bitrate_ = *total_bitrate; |
| } |
| initial_config_.reset(); |
| } |
| |
| bandwidth_estimation_->UpdateEstimate(msg.at_time); |
| absl::optional<int64_t> start_time_ms = |
| alr_detector_->GetApplicationLimitedRegionStartTime(); |
| probe_controller_->SetAlrStartTimeMs(start_time_ms); |
| |
| auto probes = probe_controller_->Process(msg.at_time.ms()); |
| update.probe_cluster_configs.insert(update.probe_cluster_configs.end(), |
| probes.begin(), probes.end()); |
| |
| MaybeTriggerOnNetworkChanged(&update, msg.at_time); |
| return update; |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::OnRemoteBitrateReport( |
| RemoteBitrateReport msg) { |
| if (packet_feedback_only_) { |
| RTC_LOG(LS_ERROR) << "Received REMB for packet feedback only GoogCC"; |
| return NetworkControlUpdate(); |
| } |
| bandwidth_estimation_->UpdateReceiverEstimate(msg.receive_time, |
| msg.bandwidth); |
| BWE_TEST_LOGGING_PLOT(1, "REMB_kbps", msg.receive_time.ms(), |
| msg.bandwidth.bps() / 1000); |
| return NetworkControlUpdate(); |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::OnRoundTripTimeUpdate( |
| RoundTripTimeUpdate msg) { |
| if (packet_feedback_only_) |
| return NetworkControlUpdate(); |
| if (msg.smoothed) { |
| delay_based_bwe_->OnRttUpdate(msg.round_trip_time); |
| } else { |
| bandwidth_estimation_->UpdateRtt(msg.round_trip_time, msg.receive_time); |
| } |
| return NetworkControlUpdate(); |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::OnSentPacket( |
| SentPacket sent_packet) { |
| alr_detector_->OnBytesSent(sent_packet.size.bytes(), |
| sent_packet.send_time.ms()); |
| if (!first_packet_sent_) { |
| first_packet_sent_ = true; |
| // Initialize feedback time to send time to allow estimation of RTT until |
| // first feedback is received. |
| bandwidth_estimation_->UpdatePropagationRtt(sent_packet.send_time, |
| TimeDelta::Zero()); |
| } |
| if (congestion_window_pushback_controller_) { |
| congestion_window_pushback_controller_->UpdateOutstandingData( |
| sent_packet.data_in_flight.bytes()); |
| NetworkControlUpdate update; |
| MaybeTriggerOnNetworkChanged(&update, sent_packet.send_time); |
| return update; |
| } else { |
| return NetworkControlUpdate(); |
| } |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::OnStreamsConfig( |
| StreamsConfig msg) { |
| NetworkControlUpdate update; |
| probe_controller_->EnablePeriodicAlrProbing(msg.requests_alr_probing); |
| if (msg.max_total_allocated_bitrate && |
| *msg.max_total_allocated_bitrate != max_total_allocated_bitrate_) { |
| update.probe_cluster_configs = |
| probe_controller_->OnMaxTotalAllocatedBitrate( |
| msg.max_total_allocated_bitrate->bps(), msg.at_time.ms()); |
| max_total_allocated_bitrate_ = *msg.max_total_allocated_bitrate; |
| } |
| bool pacing_changed = false; |
| if (msg.pacing_factor && *msg.pacing_factor != pacing_factor_) { |
| pacing_factor_ = *msg.pacing_factor; |
| pacing_changed = true; |
| } |
| if (msg.min_pacing_rate && *msg.min_pacing_rate != min_pacing_rate_) { |
| min_pacing_rate_ = *msg.min_pacing_rate; |
| pacing_changed = true; |
| } |
| if (msg.max_padding_rate && *msg.max_padding_rate != max_padding_rate_) { |
| max_padding_rate_ = *msg.max_padding_rate; |
| pacing_changed = true; |
| } |
| acknowledged_bitrate_estimator_->SetAllocatedBitrateWithoutFeedback( |
| msg.unacknowledged_rate_allocation.bps()); |
| |
| if (pacing_changed) |
| update.pacer_config = GetPacingRates(msg.at_time); |
| return update; |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::OnTargetRateConstraints( |
| TargetRateConstraints constraints) { |
| NetworkControlUpdate update; |
| update.probe_cluster_configs = |
| UpdateBitrateConstraints(constraints, constraints.starting_rate); |
| MaybeTriggerOnNetworkChanged(&update, constraints.at_time); |
| return update; |
| } |
| |
| std::vector<ProbeClusterConfig> |
| GoogCcNetworkController::UpdateBitrateConstraints( |
| TargetRateConstraints constraints, |
| absl::optional<DataRate> starting_rate) { |
| int64_t min_bitrate_bps = GetBpsOrDefault(constraints.min_data_rate, 0); |
| int64_t max_bitrate_bps = GetBpsOrDefault(constraints.max_data_rate, -1); |
| int64_t start_bitrate_bps = GetBpsOrDefault(starting_rate, -1); |
| |
| ClampBitrates(&start_bitrate_bps, &min_bitrate_bps, &max_bitrate_bps); |
| |
| std::vector<ProbeClusterConfig> probes(probe_controller_->SetBitrates( |
| min_bitrate_bps, start_bitrate_bps, max_bitrate_bps, |
| constraints.at_time.ms())); |
| |
| bandwidth_estimation_->SetBitrates( |
| starting_rate, DataRate::bps(min_bitrate_bps), |
| constraints.max_data_rate.value_or(DataRate::Infinity()), |
| constraints.at_time); |
| if (starting_rate) |
| delay_based_bwe_->SetStartBitrate(*starting_rate); |
| delay_based_bwe_->SetMinBitrate(DataRate::bps(min_bitrate_bps)); |
| return probes; |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::OnTransportLossReport( |
| TransportLossReport msg) { |
| if (packet_feedback_only_) |
| return NetworkControlUpdate(); |
| int64_t total_packets_delta = |
| msg.packets_received_delta + msg.packets_lost_delta; |
| bandwidth_estimation_->UpdatePacketsLost( |
| msg.packets_lost_delta, total_packets_delta, msg.receive_time); |
| return NetworkControlUpdate(); |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::OnTransportPacketsFeedback( |
| TransportPacketsFeedback report) { |
| if (report.packet_feedbacks.empty()) { |
| DelayBasedBwe::Result result = delay_based_bwe_->OnDelayedFeedback( |
| report.sendless_arrival_times.back()); |
| NetworkControlUpdate update; |
| if (result.updated) { |
| bandwidth_estimation_->UpdateDelayBasedEstimate(report.feedback_time, |
| result.target_bitrate); |
| MaybeTriggerOnNetworkChanged(&update, report.feedback_time); |
| } |
| return update; |
| } |
| |
| if (congestion_window_pushback_controller_) { |
| congestion_window_pushback_controller_->UpdateOutstandingData( |
| report.data_in_flight.bytes()); |
| } |
| TimeDelta max_feedback_rtt = TimeDelta::MinusInfinity(); |
| TimeDelta min_propagation_rtt = TimeDelta::PlusInfinity(); |
| Timestamp max_recv_time = Timestamp::MinusInfinity(); |
| |
| std::vector<PacketResult> feedbacks = report.ReceivedWithSendInfo(); |
| for (const auto& feedback : feedbacks) |
| max_recv_time = std::max(max_recv_time, feedback.receive_time); |
| |
| for (const auto& feedback : feedbacks) { |
| TimeDelta feedback_rtt = |
| report.feedback_time - feedback.sent_packet.send_time; |
| TimeDelta min_pending_time = feedback.receive_time - max_recv_time; |
| TimeDelta propagation_rtt = feedback_rtt - min_pending_time; |
| max_feedback_rtt = std::max(max_feedback_rtt, feedback_rtt); |
| min_propagation_rtt = std::min(min_propagation_rtt, propagation_rtt); |
| } |
| |
| if (max_feedback_rtt.IsFinite()) { |
| feedback_max_rtts_.push_back(max_feedback_rtt.ms()); |
| const size_t kMaxFeedbackRttWindow = 32; |
| if (feedback_max_rtts_.size() > kMaxFeedbackRttWindow) |
| feedback_max_rtts_.pop_front(); |
| // TODO(srte): Use time since last unacknowledged packet. |
| bandwidth_estimation_->UpdatePropagationRtt(report.feedback_time, |
| min_propagation_rtt); |
| } |
| if (packet_feedback_only_) { |
| if (!feedback_max_rtts_.empty()) { |
| int64_t sum_rtt_ms = std::accumulate(feedback_max_rtts_.begin(), |
| feedback_max_rtts_.end(), 0); |
| int64_t mean_rtt_ms = sum_rtt_ms / feedback_max_rtts_.size(); |
| delay_based_bwe_->OnRttUpdate(TimeDelta::ms(mean_rtt_ms)); |
| } |
| |
| TimeDelta feedback_min_rtt = TimeDelta::PlusInfinity(); |
| for (const auto& packet_feedback : feedbacks) { |
| TimeDelta pending_time = packet_feedback.receive_time - max_recv_time; |
| TimeDelta rtt = report.feedback_time - |
| packet_feedback.sent_packet.send_time - pending_time; |
| // Value used for predicting NACK round trip time in FEC controller. |
| feedback_min_rtt = std::min(rtt, feedback_min_rtt); |
| } |
| if (feedback_min_rtt.IsFinite()) { |
| bandwidth_estimation_->UpdateRtt(feedback_min_rtt, report.feedback_time); |
| } |
| |
| expected_packets_since_last_loss_update_ += |
| report.PacketsWithFeedback().size(); |
| for (const auto& packet_feedback : report.PacketsWithFeedback()) { |
| if (packet_feedback.receive_time.IsInfinite()) |
| lost_packets_since_last_loss_update_ += 1; |
| } |
| if (report.feedback_time > next_loss_update_) { |
| next_loss_update_ = report.feedback_time + kLossUpdateInterval; |
| bandwidth_estimation_->UpdatePacketsLost( |
| lost_packets_since_last_loss_update_, |
| expected_packets_since_last_loss_update_, report.feedback_time); |
| expected_packets_since_last_loss_update_ = 0; |
| lost_packets_since_last_loss_update_ = 0; |
| } |
| } |
| |
| std::vector<PacketFeedback> received_feedback_vector = |
| ReceivedPacketsFeedbackAsRtp(report); |
| |
| absl::optional<int64_t> alr_start_time = |
| alr_detector_->GetApplicationLimitedRegionStartTime(); |
| |
| if (previously_in_alr && !alr_start_time.has_value()) { |
| int64_t now_ms = report.feedback_time.ms(); |
| acknowledged_bitrate_estimator_->SetAlrEndedTimeMs(now_ms); |
| probe_controller_->SetAlrEndedTimeMs(now_ms); |
| } |
| previously_in_alr = alr_start_time.has_value(); |
| acknowledged_bitrate_estimator_->IncomingPacketFeedbackVector( |
| received_feedback_vector); |
| auto acknowledged_bitrate = acknowledged_bitrate_estimator_->bitrate(); |
| for (const auto& feedback : received_feedback_vector) { |
| if (feedback.pacing_info.probe_cluster_id != PacedPacketInfo::kNotAProbe) { |
| probe_bitrate_estimator_->HandleProbeAndEstimateBitrate(feedback); |
| } |
| } |
| absl::optional<DataRate> probe_bitrate = |
| probe_bitrate_estimator_->FetchAndResetLastEstimatedBitrate(); |
| if (fall_back_to_probe_rate_ && !acknowledged_bitrate) |
| acknowledged_bitrate = probe_bitrate_estimator_->last_estimate(); |
| bandwidth_estimation_->SetAcknowledgedRate(acknowledged_bitrate, |
| report.feedback_time); |
| bandwidth_estimation_->IncomingPacketFeedbackVector(report); |
| DelayBasedBwe::Result result; |
| result = delay_based_bwe_->IncomingPacketFeedbackVector( |
| received_feedback_vector, acknowledged_bitrate, probe_bitrate, |
| report.feedback_time); |
| |
| NetworkControlUpdate update; |
| if (result.updated) { |
| if (result.probe) { |
| bandwidth_estimation_->SetSendBitrate(result.target_bitrate, |
| report.feedback_time); |
| } |
| // Since SetSendBitrate now resets the delay-based estimate, we have to call |
| // UpdateDelayBasedEstimate after SetSendBitrate. |
| bandwidth_estimation_->UpdateDelayBasedEstimate(report.feedback_time, |
| result.target_bitrate); |
| // Update the estimate in the ProbeController, in case we want to probe. |
| MaybeTriggerOnNetworkChanged(&update, report.feedback_time); |
| } |
| if (result.recovered_from_overuse) { |
| probe_controller_->SetAlrStartTimeMs(alr_start_time); |
| auto probes = probe_controller_->RequestProbe(report.feedback_time.ms()); |
| update.probe_cluster_configs.insert(update.probe_cluster_configs.end(), |
| probes.begin(), probes.end()); |
| } |
| |
| // No valid RTT could be because send-side BWE isn't used, in which case |
| // we don't try to limit the outstanding packets. |
| if (in_cwnd_experiment_ && max_feedback_rtt.IsFinite()) { |
| int64_t min_feedback_max_rtt_ms = |
| *std::min_element(feedback_max_rtts_.begin(), feedback_max_rtts_.end()); |
| |
| const DataSize kMinCwnd = DataSize::bytes(2 * 1500); |
| TimeDelta time_window = |
| TimeDelta::ms(min_feedback_max_rtt_ms + accepted_queue_ms_); |
| DataSize data_window = last_target_rate_ * time_window; |
| if (current_data_window_) { |
| data_window = |
| std::max(kMinCwnd, (data_window + current_data_window_.value()) / 2); |
| } else { |
| data_window = std::max(kMinCwnd, data_window); |
| } |
| current_data_window_ = data_window; |
| } |
| if (congestion_window_pushback_controller_ && current_data_window_) { |
| congestion_window_pushback_controller_->SetDataWindow( |
| *current_data_window_); |
| } else { |
| update.congestion_window = current_data_window_; |
| } |
| |
| return update; |
| } |
| |
| NetworkControlUpdate GoogCcNetworkController::GetNetworkState( |
| Timestamp at_time) const { |
| DataRate bandwidth = DataRate::bps(last_estimated_bitrate_bps_); |
| TimeDelta rtt = TimeDelta::ms(last_estimated_rtt_ms_); |
| NetworkControlUpdate update; |
| update.target_rate = TargetTransferRate(); |
| update.target_rate->network_estimate.at_time = at_time; |
| update.target_rate->network_estimate.bandwidth = bandwidth; |
| update.target_rate->network_estimate.loss_rate_ratio = |
| last_estimated_fraction_loss_ / 255.0; |
| update.target_rate->network_estimate.round_trip_time = rtt; |
| update.target_rate->network_estimate.bwe_period = |
| delay_based_bwe_->GetExpectedBwePeriod(); |
| update.target_rate->at_time = at_time; |
| update.target_rate->target_rate = bandwidth; |
| update.pacer_config = GetPacingRates(at_time); |
| update.congestion_window = current_data_window_; |
| return update; |
| } |
| |
| |
| void GoogCcNetworkController::MaybeTriggerOnNetworkChanged( |
| NetworkControlUpdate* update, |
| Timestamp at_time) { |
| int32_t estimated_bitrate_bps; |
| uint8_t fraction_loss; |
| int64_t rtt_ms; |
| bandwidth_estimation_->CurrentEstimate(&estimated_bitrate_bps, &fraction_loss, |
| &rtt_ms); |
| |
| estimated_bitrate_bps = std::max<int32_t>( |
| estimated_bitrate_bps, bandwidth_estimation_->GetMinBitrate()); |
| |
| BWE_TEST_LOGGING_PLOT(1, "fraction_loss_%", at_time.ms(), |
| (fraction_loss * 100) / 256); |
| BWE_TEST_LOGGING_PLOT(1, "rtt_ms", at_time.ms(), rtt_ms); |
| BWE_TEST_LOGGING_PLOT(1, "Target_bitrate_kbps", at_time.ms(), |
| estimated_bitrate_bps / 1000); |
| |
| if ((estimated_bitrate_bps != last_estimated_bitrate_bps_) || |
| (fraction_loss != last_estimated_fraction_loss_) || |
| (rtt_ms != last_estimated_rtt_ms_)) { |
| last_estimated_bitrate_bps_ = estimated_bitrate_bps; |
| last_estimated_fraction_loss_ = fraction_loss; |
| last_estimated_rtt_ms_ = rtt_ms; |
| |
| alr_detector_->SetEstimatedBitrate(estimated_bitrate_bps); |
| |
| last_target_rate_ = DataRate::bps(estimated_bitrate_bps); |
| DataRate bandwidth = use_stable_bandwidth_estimate_ |
| ? bandwidth_estimation_->GetEstimatedLinkCapacity() |
| : last_target_rate_; |
| |
| TimeDelta bwe_period = delay_based_bwe_->GetExpectedBwePeriod(); |
| |
| // Set the target rate to the full estimated bandwidth since the estimation |
| // for legacy reasons includes target rate constraints. |
| DataRate target_rate = last_target_rate_; |
| if (congestion_window_pushback_controller_) { |
| int64_t pushback_rate = |
| congestion_window_pushback_controller_->UpdateTargetBitrate( |
| target_rate.bps()); |
| pushback_rate = std::max<int64_t>(bandwidth_estimation_->GetMinBitrate(), |
| pushback_rate); |
| target_rate = DataRate::bps(pushback_rate); |
| } |
| |
| TargetTransferRate target_rate_msg; |
| target_rate_msg.at_time = at_time; |
| target_rate_msg.target_rate = target_rate; |
| target_rate_msg.network_estimate.at_time = at_time; |
| target_rate_msg.network_estimate.round_trip_time = TimeDelta::ms(rtt_ms); |
| target_rate_msg.network_estimate.bandwidth = bandwidth; |
| target_rate_msg.network_estimate.loss_rate_ratio = fraction_loss / 255.0f; |
| target_rate_msg.network_estimate.bwe_period = bwe_period; |
| |
| update->target_rate = target_rate_msg; |
| |
| auto probes = probe_controller_->SetEstimatedBitrate( |
| last_target_rate_.bps(), at_time.ms()); |
| update->probe_cluster_configs.insert(update->probe_cluster_configs.end(), |
| probes.begin(), probes.end()); |
| update->pacer_config = GetPacingRates(at_time); |
| } |
| } |
| |
| PacerConfig GoogCcNetworkController::GetPacingRates(Timestamp at_time) const { |
| DataRate pacing_rate = |
| std::max(min_pacing_rate_, last_target_rate_) * pacing_factor_; |
| DataRate padding_rate = std::min(max_padding_rate_, last_target_rate_); |
| PacerConfig msg; |
| msg.at_time = at_time; |
| msg.time_window = TimeDelta::seconds(1); |
| msg.data_window = pacing_rate * msg.time_window; |
| msg.pad_window = padding_rate * msg.time_window; |
| return msg; |
| } |
| |
| } // namespace webrtc |
