| /* |
| * Copyright (c) 2013 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/remote_bitrate_estimator/remote_bitrate_estimator_abs_send_time.h" |
| |
| #include <math.h> |
| |
| #include <algorithm> |
| |
| #include "webrtc/modules/pacing/paced_sender.h" |
| #include "webrtc/modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h" |
| #include "webrtc/rtc_base/checks.h" |
| #include "webrtc/rtc_base/constructormagic.h" |
| #include "webrtc/rtc_base/logging.h" |
| #include "webrtc/rtc_base/thread_annotations.h" |
| #include "webrtc/system_wrappers/include/metrics.h" |
| #include "webrtc/typedefs.h" |
| |
| namespace webrtc { |
| |
| enum { |
| kTimestampGroupLengthMs = 5, |
| kAbsSendTimeFraction = 18, |
| kAbsSendTimeInterArrivalUpshift = 8, |
| kInterArrivalShift = kAbsSendTimeFraction + kAbsSendTimeInterArrivalUpshift, |
| kInitialProbingIntervalMs = 2000, |
| kMinClusterSize = 4, |
| kMaxProbePackets = 15, |
| kExpectedNumberOfProbes = 3 |
| }; |
| |
| static const double kTimestampToMs = 1000.0 / |
| static_cast<double>(1 << kInterArrivalShift); |
| |
| template<typename K, typename V> |
| std::vector<K> Keys(const std::map<K, V>& map) { |
| std::vector<K> keys; |
| keys.reserve(map.size()); |
| for (typename std::map<K, V>::const_iterator it = map.begin(); |
| it != map.end(); ++it) { |
| keys.push_back(it->first); |
| } |
| return keys; |
| } |
| |
| uint32_t ConvertMsTo24Bits(int64_t time_ms) { |
| uint32_t time_24_bits = |
| static_cast<uint32_t>( |
| ((static_cast<uint64_t>(time_ms) << kAbsSendTimeFraction) + 500) / |
| 1000) & |
| 0x00FFFFFF; |
| return time_24_bits; |
| } |
| |
| bool RemoteBitrateEstimatorAbsSendTime::IsWithinClusterBounds( |
| int send_delta_ms, |
| const Cluster& cluster_aggregate) { |
| if (cluster_aggregate.count == 0) |
| return true; |
| float cluster_mean = cluster_aggregate.send_mean_ms / |
| static_cast<float>(cluster_aggregate.count); |
| return fabs(static_cast<float>(send_delta_ms) - cluster_mean) < 2.5f; |
| } |
| |
| void RemoteBitrateEstimatorAbsSendTime::AddCluster( |
| std::list<Cluster>* clusters, |
| Cluster* cluster) { |
| cluster->send_mean_ms /= static_cast<float>(cluster->count); |
| cluster->recv_mean_ms /= static_cast<float>(cluster->count); |
| cluster->mean_size /= cluster->count; |
| clusters->push_back(*cluster); |
| } |
| |
| RemoteBitrateEstimatorAbsSendTime::RemoteBitrateEstimatorAbsSendTime( |
| RemoteBitrateObserver* observer, |
| const Clock* clock) |
| : clock_(clock), |
| observer_(observer), |
| inter_arrival_(), |
| estimator_(), |
| detector_(), |
| incoming_bitrate_(kBitrateWindowMs, 8000), |
| incoming_bitrate_initialized_(false), |
| total_probes_received_(0), |
| first_packet_time_ms_(-1), |
| last_update_ms_(-1), |
| uma_recorded_(false) { |
| RTC_DCHECK(observer_); |
| LOG(LS_INFO) << "RemoteBitrateEstimatorAbsSendTime: Instantiating."; |
| } |
| |
| void RemoteBitrateEstimatorAbsSendTime::ComputeClusters( |
| std::list<Cluster>* clusters) const { |
| Cluster current; |
| int64_t prev_send_time = -1; |
| int64_t prev_recv_time = -1; |
| for (std::list<Probe>::const_iterator it = probes_.begin(); |
| it != probes_.end(); |
| ++it) { |
| if (prev_send_time >= 0) { |
| int send_delta_ms = it->send_time_ms - prev_send_time; |
| int recv_delta_ms = it->recv_time_ms - prev_recv_time; |
| if (send_delta_ms >= 1 && recv_delta_ms >= 1) { |
| ++current.num_above_min_delta; |
| } |
| if (!IsWithinClusterBounds(send_delta_ms, current)) { |
| if (current.count >= kMinClusterSize && |
| current.send_mean_ms > 0.0f && |
| current.recv_mean_ms > 0.0f) { |
| AddCluster(clusters, ¤t); |
| } |
| current = Cluster(); |
| } |
| current.send_mean_ms += send_delta_ms; |
| current.recv_mean_ms += recv_delta_ms; |
| current.mean_size += it->payload_size; |
| ++current.count; |
| } |
| prev_send_time = it->send_time_ms; |
| prev_recv_time = it->recv_time_ms; |
| } |
| if (current.count >= kMinClusterSize && |
| current.send_mean_ms > 0.0f && |
| current.recv_mean_ms > 0.0f) { |
| AddCluster(clusters, ¤t); |
| } |
| } |
| |
| std::list<Cluster>::const_iterator |
| RemoteBitrateEstimatorAbsSendTime::FindBestProbe( |
| const std::list<Cluster>& clusters) const { |
| int highest_probe_bitrate_bps = 0; |
| std::list<Cluster>::const_iterator best_it = clusters.end(); |
| for (std::list<Cluster>::const_iterator it = clusters.begin(); |
| it != clusters.end(); |
| ++it) { |
| if (it->send_mean_ms == 0 || it->recv_mean_ms == 0) |
| continue; |
| if (it->num_above_min_delta > it->count / 2 && |
| (it->recv_mean_ms - it->send_mean_ms <= 2.0f && |
| it->send_mean_ms - it->recv_mean_ms <= 5.0f)) { |
| int probe_bitrate_bps = |
| std::min(it->GetSendBitrateBps(), it->GetRecvBitrateBps()); |
| if (probe_bitrate_bps > highest_probe_bitrate_bps) { |
| highest_probe_bitrate_bps = probe_bitrate_bps; |
| best_it = it; |
| } |
| } else { |
| int send_bitrate_bps = it->mean_size * 8 * 1000 / it->send_mean_ms; |
| int recv_bitrate_bps = it->mean_size * 8 * 1000 / it->recv_mean_ms; |
| LOG(LS_INFO) << "Probe failed, sent at " << send_bitrate_bps |
| << " bps, received at " << recv_bitrate_bps |
| << " bps. Mean send delta: " << it->send_mean_ms |
| << " ms, mean recv delta: " << it->recv_mean_ms |
| << " ms, num probes: " << it->count; |
| break; |
| } |
| } |
| return best_it; |
| } |
| |
| RemoteBitrateEstimatorAbsSendTime::ProbeResult |
| RemoteBitrateEstimatorAbsSendTime::ProcessClusters(int64_t now_ms) { |
| std::list<Cluster> clusters; |
| ComputeClusters(&clusters); |
| if (clusters.empty()) { |
| // If we reach the max number of probe packets and still have no clusters, |
| // we will remove the oldest one. |
| if (probes_.size() >= kMaxProbePackets) |
| probes_.pop_front(); |
| return ProbeResult::kNoUpdate; |
| } |
| |
| std::list<Cluster>::const_iterator best_it = FindBestProbe(clusters); |
| if (best_it != clusters.end()) { |
| int probe_bitrate_bps = |
| std::min(best_it->GetSendBitrateBps(), best_it->GetRecvBitrateBps()); |
| // Make sure that a probe sent on a lower bitrate than our estimate can't |
| // reduce the estimate. |
| if (IsBitrateImproving(probe_bitrate_bps)) { |
| LOG(LS_INFO) << "Probe successful, sent at " |
| << best_it->GetSendBitrateBps() << " bps, received at " |
| << best_it->GetRecvBitrateBps() |
| << " bps. Mean send delta: " << best_it->send_mean_ms |
| << " ms, mean recv delta: " << best_it->recv_mean_ms |
| << " ms, num probes: " << best_it->count; |
| remote_rate_.SetEstimate(probe_bitrate_bps, now_ms); |
| return ProbeResult::kBitrateUpdated; |
| } |
| } |
| |
| // Not probing and received non-probe packet, or finished with current set |
| // of probes. |
| if (clusters.size() >= kExpectedNumberOfProbes) |
| probes_.clear(); |
| return ProbeResult::kNoUpdate; |
| } |
| |
| bool RemoteBitrateEstimatorAbsSendTime::IsBitrateImproving( |
| int new_bitrate_bps) const { |
| bool initial_probe = !remote_rate_.ValidEstimate() && new_bitrate_bps > 0; |
| bool bitrate_above_estimate = |
| remote_rate_.ValidEstimate() && |
| new_bitrate_bps > static_cast<int>(remote_rate_.LatestEstimate()); |
| return initial_probe || bitrate_above_estimate; |
| } |
| |
| void RemoteBitrateEstimatorAbsSendTime::IncomingPacket( |
| int64_t arrival_time_ms, |
| size_t payload_size, |
| const RTPHeader& header) { |
| RTC_DCHECK_RUNS_SERIALIZED(&network_race_); |
| if (!header.extension.hasAbsoluteSendTime) { |
| LOG(LS_WARNING) << "RemoteBitrateEstimatorAbsSendTimeImpl: Incoming packet " |
| "is missing absolute send time extension!"; |
| return; |
| } |
| IncomingPacketInfo(arrival_time_ms, header.extension.absoluteSendTime, |
| payload_size, header.ssrc); |
| } |
| |
| void RemoteBitrateEstimatorAbsSendTime::IncomingPacketInfo( |
| int64_t arrival_time_ms, |
| uint32_t send_time_24bits, |
| size_t payload_size, |
| uint32_t ssrc) { |
| RTC_CHECK(send_time_24bits < (1ul << 24)); |
| if (!uma_recorded_) { |
| RTC_HISTOGRAM_ENUMERATION(kBweTypeHistogram, BweNames::kReceiverAbsSendTime, |
| BweNames::kBweNamesMax); |
| uma_recorded_ = true; |
| } |
| // Shift up send time to use the full 32 bits that inter_arrival works with, |
| // so wrapping works properly. |
| uint32_t timestamp = send_time_24bits << kAbsSendTimeInterArrivalUpshift; |
| int64_t send_time_ms = static_cast<int64_t>(timestamp) * kTimestampToMs; |
| |
| int64_t now_ms = clock_->TimeInMilliseconds(); |
| // TODO(holmer): SSRCs are only needed for REMB, should be broken out from |
| // here. |
| |
| // Check if incoming bitrate estimate is valid, and if it needs to be reset. |
| rtc::Optional<uint32_t> incoming_bitrate = |
| incoming_bitrate_.Rate(arrival_time_ms); |
| if (incoming_bitrate) { |
| incoming_bitrate_initialized_ = true; |
| } else if (incoming_bitrate_initialized_) { |
| // Incoming bitrate had a previous valid value, but now not enough data |
| // point are left within the current window. Reset incoming bitrate |
| // estimator so that the window size will only contain new data points. |
| incoming_bitrate_.Reset(); |
| incoming_bitrate_initialized_ = false; |
| } |
| incoming_bitrate_.Update(payload_size, arrival_time_ms); |
| |
| if (first_packet_time_ms_ == -1) |
| first_packet_time_ms_ = now_ms; |
| |
| uint32_t ts_delta = 0; |
| int64_t t_delta = 0; |
| int size_delta = 0; |
| bool update_estimate = false; |
| uint32_t target_bitrate_bps = 0; |
| std::vector<uint32_t> ssrcs; |
| { |
| rtc::CritScope lock(&crit_); |
| |
| TimeoutStreams(now_ms); |
| RTC_DCHECK(inter_arrival_.get()); |
| RTC_DCHECK(estimator_.get()); |
| ssrcs_[ssrc] = now_ms; |
| |
| // For now only try to detect probes while we don't have a valid estimate. |
| // We currently assume that only packets larger than 200 bytes are paced by |
| // the sender. |
| const size_t kMinProbePacketSize = 200; |
| if (payload_size > kMinProbePacketSize && |
| (!remote_rate_.ValidEstimate() || |
| now_ms - first_packet_time_ms_ < kInitialProbingIntervalMs)) { |
| // TODO(holmer): Use a map instead to get correct order? |
| if (total_probes_received_ < kMaxProbePackets) { |
| int send_delta_ms = -1; |
| int recv_delta_ms = -1; |
| if (!probes_.empty()) { |
| send_delta_ms = send_time_ms - probes_.back().send_time_ms; |
| recv_delta_ms = arrival_time_ms - probes_.back().recv_time_ms; |
| } |
| LOG(LS_INFO) << "Probe packet received: send time=" << send_time_ms |
| << " ms, recv time=" << arrival_time_ms |
| << " ms, send delta=" << send_delta_ms |
| << " ms, recv delta=" << recv_delta_ms << " ms."; |
| } |
| probes_.push_back(Probe(send_time_ms, arrival_time_ms, payload_size)); |
| ++total_probes_received_; |
| // Make sure that a probe which updated the bitrate immediately has an |
| // effect by calling the OnReceiveBitrateChanged callback. |
| if (ProcessClusters(now_ms) == ProbeResult::kBitrateUpdated) |
| update_estimate = true; |
| } |
| if (inter_arrival_->ComputeDeltas(timestamp, arrival_time_ms, now_ms, |
| payload_size, &ts_delta, &t_delta, |
| &size_delta)) { |
| double ts_delta_ms = (1000.0 * ts_delta) / (1 << kInterArrivalShift); |
| estimator_->Update(t_delta, ts_delta_ms, size_delta, detector_.State(), |
| arrival_time_ms); |
| detector_.Detect(estimator_->offset(), ts_delta_ms, |
| estimator_->num_of_deltas(), arrival_time_ms); |
| } |
| |
| if (!update_estimate) { |
| // Check if it's time for a periodic update or if we should update because |
| // of an over-use. |
| if (last_update_ms_ == -1 || |
| now_ms - last_update_ms_ > remote_rate_.GetFeedbackInterval()) { |
| update_estimate = true; |
| } else if (detector_.State() == BandwidthUsage::kBwOverusing) { |
| rtc::Optional<uint32_t> incoming_rate = |
| incoming_bitrate_.Rate(arrival_time_ms); |
| if (incoming_rate && |
| remote_rate_.TimeToReduceFurther(now_ms, *incoming_rate)) { |
| update_estimate = true; |
| } |
| } |
| } |
| |
| if (update_estimate) { |
| // The first overuse should immediately trigger a new estimate. |
| // We also have to update the estimate immediately if we are overusing |
| // and the target bitrate is too high compared to what we are receiving. |
| const RateControlInput input(detector_.State(), |
| incoming_bitrate_.Rate(arrival_time_ms), |
| estimator_->var_noise()); |
| target_bitrate_bps = remote_rate_.Update(&input, now_ms); |
| update_estimate = remote_rate_.ValidEstimate(); |
| ssrcs = Keys(ssrcs_); |
| } |
| } |
| if (update_estimate) { |
| last_update_ms_ = now_ms; |
| observer_->OnReceiveBitrateChanged(ssrcs, target_bitrate_bps); |
| } |
| } |
| |
| void RemoteBitrateEstimatorAbsSendTime::Process() {} |
| |
| int64_t RemoteBitrateEstimatorAbsSendTime::TimeUntilNextProcess() { |
| const int64_t kDisabledModuleTime = 1000; |
| return kDisabledModuleTime; |
| } |
| |
| void RemoteBitrateEstimatorAbsSendTime::TimeoutStreams(int64_t now_ms) { |
| for (Ssrcs::iterator it = ssrcs_.begin(); it != ssrcs_.end();) { |
| if ((now_ms - it->second) > kStreamTimeOutMs) { |
| ssrcs_.erase(it++); |
| } else { |
| ++it; |
| } |
| } |
| if (ssrcs_.empty()) { |
| // We can't update the estimate if we don't have any active streams. |
| inter_arrival_.reset( |
| new InterArrival((kTimestampGroupLengthMs << kInterArrivalShift) / 1000, |
| kTimestampToMs, true)); |
| estimator_.reset(new OveruseEstimator(OverUseDetectorOptions())); |
| // We deliberately don't reset the first_packet_time_ms_ here for now since |
| // we only probe for bandwidth in the beginning of a call right now. |
| } |
| } |
| |
| void RemoteBitrateEstimatorAbsSendTime::OnRttUpdate(int64_t avg_rtt_ms, |
| int64_t max_rtt_ms) { |
| rtc::CritScope lock(&crit_); |
| remote_rate_.SetRtt(avg_rtt_ms); |
| } |
| |
| void RemoteBitrateEstimatorAbsSendTime::RemoveStream(uint32_t ssrc) { |
| rtc::CritScope lock(&crit_); |
| ssrcs_.erase(ssrc); |
| } |
| |
| bool RemoteBitrateEstimatorAbsSendTime::LatestEstimate( |
| std::vector<uint32_t>* ssrcs, |
| uint32_t* bitrate_bps) const { |
| // Currently accessed from both the process thread (see |
| // ModuleRtpRtcpImpl::Process()) and the configuration thread (see |
| // Call::GetStats()). Should in the future only be accessed from a single |
| // thread. |
| RTC_DCHECK(ssrcs); |
| RTC_DCHECK(bitrate_bps); |
| rtc::CritScope lock(&crit_); |
| if (!remote_rate_.ValidEstimate()) { |
| return false; |
| } |
| *ssrcs = Keys(ssrcs_); |
| if (ssrcs_.empty()) { |
| *bitrate_bps = 0; |
| } else { |
| *bitrate_bps = remote_rate_.LatestEstimate(); |
| } |
| return true; |
| } |
| |
| void RemoteBitrateEstimatorAbsSendTime::SetMinBitrate(int min_bitrate_bps) { |
| // Called from both the configuration thread and the network thread. Shouldn't |
| // be called from the network thread in the future. |
| rtc::CritScope lock(&crit_); |
| remote_rate_.SetMinBitrate(min_bitrate_bps); |
| } |
| } // namespace webrtc |