modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.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 "modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h"

 #include <assert.h>

 #include <cstdint>
 #include <utility>

 #include "absl/types/optional.h"
 #include "modules/remote_bitrate_estimator/aimd_rate_control.h"
 #include "modules/remote_bitrate_estimator/include/bwe_defines.h"
 #include "modules/remote_bitrate_estimator/inter_arrival.h"
 #include "modules/remote_bitrate_estimator/overuse_detector.h"
 #include "modules/remote_bitrate_estimator/overuse_estimator.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"
 #include "system_wrappers/include/clock.h"
 #include "system_wrappers/include/metrics.h"

 namespace webrtc {
 namespace {
 absl::optional<DataRate> OptionalRateFromOptionalBps(
     absl::optional<int> bitrate_bps) {
   if (bitrate_bps) {
     return DataRate::BitsPerSec(*bitrate_bps);
   } else {
     return absl::nullopt;
   }
 }
 }  // namespace

 enum { kTimestampGroupLengthMs = 5 };
 static const double kTimestampToMs = 1.0 / 90.0;

 struct RemoteBitrateEstimatorSingleStream::Detector {
   explicit Detector(int64_t last_packet_time_ms,
                     const OverUseDetectorOptions& options,
                     bool enable_burst_grouping,
                     const WebRtcKeyValueConfig* key_value_config)
       : last_packet_time_ms(last_packet_time_ms),
         inter_arrival(90 * kTimestampGroupLengthMs,
                       kTimestampToMs,
                       enable_burst_grouping),
         estimator(options),
         detector(key_value_config) {}
   int64_t last_packet_time_ms;
   InterArrival inter_arrival;
   OveruseEstimator estimator;
   OveruseDetector detector;
 };

 RemoteBitrateEstimatorSingleStream::RemoteBitrateEstimatorSingleStream(
     RemoteBitrateObserver* observer,
     Clock* clock)
     : clock_(clock),
       incoming_bitrate_(kBitrateWindowMs, 8000),
       last_valid_incoming_bitrate_(0),
       remote_rate_(new AimdRateControl(&field_trials_)),
       observer_(observer),
       last_process_time_(-1),
       process_interval_ms_(kProcessIntervalMs),
       uma_recorded_(false) {
   RTC_LOG(LS_INFO) << "RemoteBitrateEstimatorSingleStream: Instantiating.";
 }

 RemoteBitrateEstimatorSingleStream::~RemoteBitrateEstimatorSingleStream() {
   while (!overuse_detectors_.empty()) {
     SsrcOveruseEstimatorMap::iterator it = overuse_detectors_.begin();
     delete it->second;
     overuse_detectors_.erase(it);
   }
 }

 void RemoteBitrateEstimatorSingleStream::IncomingPacket(
     int64_t arrival_time_ms,
     size_t payload_size,
     const RTPHeader& header) {
   if (!uma_recorded_) {
     BweNames type = BweNames::kReceiverTOffset;
     if (!header.extension.hasTransmissionTimeOffset)
       type = BweNames::kReceiverNoExtension;
     RTC_HISTOGRAM_ENUMERATION(kBweTypeHistogram, type, BweNames::kBweNamesMax);
     uma_recorded_ = true;
   }
   uint32_t ssrc = header.ssrc;
   uint32_t rtp_timestamp =
       header.timestamp + header.extension.transmissionTimeOffset;
   int64_t now_ms = clock_->TimeInMilliseconds();
   MutexLock lock(&mutex_);
   SsrcOveruseEstimatorMap::iterator it = overuse_detectors_.find(ssrc);
   if (it == overuse_detectors_.end()) {
     // This is a new SSRC. Adding to map.
     // TODO(holmer): If the channel changes SSRC the old SSRC will still be
     // around in this map until the channel is deleted. This is OK since the
     // callback will no longer be called for the old SSRC. This will be
     // automatically cleaned up when we have one RemoteBitrateEstimator per REMB
     // group.
     std::pair<SsrcOveruseEstimatorMap::iterator, bool> insert_result =
         overuse_detectors_.insert(
             std::make_pair(ssrc, new Detector(now_ms, OverUseDetectorOptions(),
                                               true, &field_trials_)));
     it = insert_result.first;
   }
   Detector* estimator = it->second;
   estimator->last_packet_time_ms = now_ms;

   // Check if incoming bitrate estimate is valid, and if it needs to be reset.
   absl::optional<uint32_t> incoming_bitrate = incoming_bitrate_.Rate(now_ms);
   if (incoming_bitrate) {
     last_valid_incoming_bitrate_ = *incoming_bitrate;
   } else if (last_valid_incoming_bitrate_ > 0) {
     // 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();
     last_valid_incoming_bitrate_ = 0;
   }
   incoming_bitrate_.Update(payload_size, now_ms);

   const BandwidthUsage prior_state = estimator->detector.State();
   uint32_t timestamp_delta = 0;
   int64_t time_delta = 0;
   int size_delta = 0;
   if (estimator->inter_arrival.ComputeDeltas(
           rtp_timestamp, arrival_time_ms, now_ms, payload_size,
           &timestamp_delta, &time_delta, &size_delta)) {
     double timestamp_delta_ms = timestamp_delta * kTimestampToMs;
     estimator->estimator.Update(time_delta, timestamp_delta_ms, size_delta,
                                 estimator->detector.State(), now_ms);
     estimator->detector.Detect(estimator->estimator.offset(),
                                timestamp_delta_ms,
                                estimator->estimator.num_of_deltas(), now_ms);
   }
   if (estimator->detector.State() == BandwidthUsage::kBwOverusing) {
     absl::optional<uint32_t> incoming_bitrate_bps =
         incoming_bitrate_.Rate(now_ms);
     if (incoming_bitrate_bps &&
         (prior_state != BandwidthUsage::kBwOverusing ||
          GetRemoteRate()->TimeToReduceFurther(
              Timestamp::Millis(now_ms),
              DataRate::BitsPerSec(*incoming_bitrate_bps)))) {
       // 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.
       UpdateEstimate(now_ms);
     }
   }
 }

 void RemoteBitrateEstimatorSingleStream::Process() {
   {
     MutexLock lock(&mutex_);
     UpdateEstimate(clock_->TimeInMilliseconds());
   }
   last_process_time_ = clock_->TimeInMilliseconds();
 }

 int64_t RemoteBitrateEstimatorSingleStream::TimeUntilNextProcess() {
   if (last_process_time_ < 0) {
     return 0;
   }
   MutexLock lock_(&mutex_);
   RTC_DCHECK_GT(process_interval_ms_, 0);
   return last_process_time_ + process_interval_ms_ -
          clock_->TimeInMilliseconds();
 }

 void RemoteBitrateEstimatorSingleStream::UpdateEstimate(int64_t now_ms) {
   BandwidthUsage bw_state = BandwidthUsage::kBwNormal;
   SsrcOveruseEstimatorMap::iterator it = overuse_detectors_.begin();
   while (it != overuse_detectors_.end()) {
     const int64_t time_of_last_received_packet =
         it->second->last_packet_time_ms;
     if (time_of_last_received_packet >= 0 &&
         now_ms - time_of_last_received_packet > kStreamTimeOutMs) {
       // This over-use detector hasn't received packets for |kStreamTimeOutMs|
       // milliseconds and is considered stale.
       delete it->second;
       overuse_detectors_.erase(it++);
     } else {
       // Make sure that we trigger an over-use if any of the over-use detectors
       // is detecting over-use.
       if (it->second->detector.State() > bw_state) {
         bw_state = it->second->detector.State();
       }
       ++it;
     }
   }
   // We can't update the estimate if we don't have any active streams.
   if (overuse_detectors_.empty()) {
     return;
   }
   AimdRateControl* remote_rate = GetRemoteRate();

   const RateControlInput input(
       bw_state, OptionalRateFromOptionalBps(incoming_bitrate_.Rate(now_ms)));
   uint32_t target_bitrate =
       remote_rate->Update(&input, Timestamp::Millis(now_ms)).bps<uint32_t>();
   if (remote_rate->ValidEstimate()) {
     process_interval_ms_ = remote_rate->GetFeedbackInterval().ms();
     RTC_DCHECK_GT(process_interval_ms_, 0);
     std::vector<uint32_t> ssrcs;
     GetSsrcs(&ssrcs);
     if (observer_)
       observer_->OnReceiveBitrateChanged(ssrcs, target_bitrate);
   }
 }

 void RemoteBitrateEstimatorSingleStream::OnRttUpdate(int64_t avg_rtt_ms,
                                                      int64_t max_rtt_ms) {
   MutexLock lock(&mutex_);
   GetRemoteRate()->SetRtt(TimeDelta::Millis(avg_rtt_ms));
 }

 void RemoteBitrateEstimatorSingleStream::RemoveStream(unsigned int ssrc) {
   MutexLock lock(&mutex_);
   SsrcOveruseEstimatorMap::iterator it = overuse_detectors_.find(ssrc);
   if (it != overuse_detectors_.end()) {
     delete it->second;
     overuse_detectors_.erase(it);
   }
 }

 bool RemoteBitrateEstimatorSingleStream::LatestEstimate(
     std::vector<uint32_t>* ssrcs,
     uint32_t* bitrate_bps) const {
   MutexLock lock(&mutex_);
   RTC_DCHECK(bitrate_bps);
   if (!remote_rate_->ValidEstimate()) {
     return false;
   }
   GetSsrcs(ssrcs);
   if (ssrcs->empty())
     *bitrate_bps = 0;
   else
     *bitrate_bps = remote_rate_->LatestEstimate().bps<uint32_t>();
   return true;
 }

 void RemoteBitrateEstimatorSingleStream::GetSsrcs(
     std::vector<uint32_t>* ssrcs) const {
   RTC_DCHECK(ssrcs);
   ssrcs->resize(overuse_detectors_.size());
   int i = 0;
   for (SsrcOveruseEstimatorMap::const_iterator it = overuse_detectors_.begin();
        it != overuse_detectors_.end(); ++it, ++i) {
     (*ssrcs)[i] = it->first;
   }
 }

 AimdRateControl* RemoteBitrateEstimatorSingleStream::GetRemoteRate() {
   if (!remote_rate_)
     remote_rate_.reset(new AimdRateControl(&field_trials_));
   return remote_rate_.get();
 }

 void RemoteBitrateEstimatorSingleStream::SetMinBitrate(int min_bitrate_bps) {
   MutexLock lock(&mutex_);
   remote_rate_->SetMinBitrate(DataRate::BitsPerSec(min_bitrate_bps));
 }

 }  // 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 "modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.h"

	#include <assert.h>

	#include <cstdint>
	#include <utility>

	#include "absl/types/optional.h"
	#include "modules/remote_bitrate_estimator/aimd_rate_control.h"
	#include "modules/remote_bitrate_estimator/include/bwe_defines.h"
	#include "modules/remote_bitrate_estimator/inter_arrival.h"
	#include "modules/remote_bitrate_estimator/overuse_detector.h"
	#include "modules/remote_bitrate_estimator/overuse_estimator.h"
	#include "rtc_base/checks.h"
	#include "rtc_base/logging.h"
	#include "system_wrappers/include/clock.h"
	#include "system_wrappers/include/metrics.h"

	namespace webrtc {
	namespace {
	absl::optional<DataRate> OptionalRateFromOptionalBps(
	absl::optional<int> bitrate_bps) {
	if (bitrate_bps) {
	return DataRate::BitsPerSec(*bitrate_bps);
	} else {
	return absl::nullopt;
	}
	}
	} // namespace

	enum { kTimestampGroupLengthMs = 5 };
	static const double kTimestampToMs = 1.0 / 90.0;

	struct RemoteBitrateEstimatorSingleStream::Detector {
	explicit Detector(int64_t last_packet_time_ms,
	const OverUseDetectorOptions& options,
	bool enable_burst_grouping,
	const WebRtcKeyValueConfig* key_value_config)
	: last_packet_time_ms(last_packet_time_ms),
	inter_arrival(90 * kTimestampGroupLengthMs,
	kTimestampToMs,
	enable_burst_grouping),
	estimator(options),
	detector(key_value_config) {}
	int64_t last_packet_time_ms;
	InterArrival inter_arrival;
	OveruseEstimator estimator;
	OveruseDetector detector;
	};

	RemoteBitrateEstimatorSingleStream::RemoteBitrateEstimatorSingleStream(
	RemoteBitrateObserver* observer,
	Clock* clock)
	: clock_(clock),
	incoming_bitrate_(kBitrateWindowMs, 8000),
	last_valid_incoming_bitrate_(0),
	remote_rate_(new AimdRateControl(&field_trials_)),
	observer_(observer),
	last_process_time_(-1),
	process_interval_ms_(kProcessIntervalMs),
	uma_recorded_(false) {
	RTC_LOG(LS_INFO) << "RemoteBitrateEstimatorSingleStream: Instantiating.";
	}

	RemoteBitrateEstimatorSingleStream::~RemoteBitrateEstimatorSingleStream() {
	while (!overuse_detectors_.empty()) {
	SsrcOveruseEstimatorMap::iterator it = overuse_detectors_.begin();
	delete it->second;
	overuse_detectors_.erase(it);
	}
	}

	void RemoteBitrateEstimatorSingleStream::IncomingPacket(
	int64_t arrival_time_ms,
	size_t payload_size,
	const RTPHeader& header) {
	if (!uma_recorded_) {
	BweNames type = BweNames::kReceiverTOffset;
	if (!header.extension.hasTransmissionTimeOffset)
	type = BweNames::kReceiverNoExtension;
	RTC_HISTOGRAM_ENUMERATION(kBweTypeHistogram, type, BweNames::kBweNamesMax);
	uma_recorded_ = true;
	}
	uint32_t ssrc = header.ssrc;
	uint32_t rtp_timestamp =
	header.timestamp + header.extension.transmissionTimeOffset;
	int64_t now_ms = clock_->TimeInMilliseconds();
	MutexLock lock(&mutex_);
	SsrcOveruseEstimatorMap::iterator it = overuse_detectors_.find(ssrc);
	if (it == overuse_detectors_.end()) {
	// This is a new SSRC. Adding to map.
	// TODO(holmer): If the channel changes SSRC the old SSRC will still be
	// around in this map until the channel is deleted. This is OK since the
	// callback will no longer be called for the old SSRC. This will be
	// automatically cleaned up when we have one RemoteBitrateEstimator per REMB
	// group.
	std::pair<SsrcOveruseEstimatorMap::iterator, bool> insert_result =
	overuse_detectors_.insert(
	std::make_pair(ssrc, new Detector(now_ms, OverUseDetectorOptions(),
	true, &field_trials_)));
	it = insert_result.first;
	}
	Detector* estimator = it->second;
	estimator->last_packet_time_ms = now_ms;

	// Check if incoming bitrate estimate is valid, and if it needs to be reset.
	absl::optional<uint32_t> incoming_bitrate = incoming_bitrate_.Rate(now_ms);
	if (incoming_bitrate) {
	last_valid_incoming_bitrate_ = *incoming_bitrate;
	} else if (last_valid_incoming_bitrate_ > 0) {
	// 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();
	last_valid_incoming_bitrate_ = 0;
	}
	incoming_bitrate_.Update(payload_size, now_ms);

	const BandwidthUsage prior_state = estimator->detector.State();
	uint32_t timestamp_delta = 0;
	int64_t time_delta = 0;
	int size_delta = 0;
	if (estimator->inter_arrival.ComputeDeltas(
	rtp_timestamp, arrival_time_ms, now_ms, payload_size,
	&timestamp_delta, &time_delta, &size_delta)) {
	double timestamp_delta_ms = timestamp_delta * kTimestampToMs;
	estimator->estimator.Update(time_delta, timestamp_delta_ms, size_delta,
	estimator->detector.State(), now_ms);
	estimator->detector.Detect(estimator->estimator.offset(),
	timestamp_delta_ms,
	estimator->estimator.num_of_deltas(), now_ms);
	}
	if (estimator->detector.State() == BandwidthUsage::kBwOverusing) {
	absl::optional<uint32_t> incoming_bitrate_bps =
	incoming_bitrate_.Rate(now_ms);
	if (incoming_bitrate_bps &&
	(prior_state != BandwidthUsage::kBwOverusing \|\|
	GetRemoteRate()->TimeToReduceFurther(
	Timestamp::Millis(now_ms),
	DataRate::BitsPerSec(*incoming_bitrate_bps)))) {
	// 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.
	UpdateEstimate(now_ms);
	}
	}
	}

	void RemoteBitrateEstimatorSingleStream::Process() {
	{
	MutexLock lock(&mutex_);
	UpdateEstimate(clock_->TimeInMilliseconds());
	}
	last_process_time_ = clock_->TimeInMilliseconds();
	}

	int64_t RemoteBitrateEstimatorSingleStream::TimeUntilNextProcess() {
	if (last_process_time_ < 0) {
	return 0;
	}
	MutexLock lock_(&mutex_);
	RTC_DCHECK_GT(process_interval_ms_, 0);
	return last_process_time_ + process_interval_ms_ -
	clock_->TimeInMilliseconds();
	}

	void RemoteBitrateEstimatorSingleStream::UpdateEstimate(int64_t now_ms) {
	BandwidthUsage bw_state = BandwidthUsage::kBwNormal;
	SsrcOveruseEstimatorMap::iterator it = overuse_detectors_.begin();
	while (it != overuse_detectors_.end()) {
	const int64_t time_of_last_received_packet =
	it->second->last_packet_time_ms;
	if (time_of_last_received_packet >= 0 &&
	now_ms - time_of_last_received_packet > kStreamTimeOutMs) {
	// This over-use detector hasn't received packets for \|kStreamTimeOutMs\|
	// milliseconds and is considered stale.
	delete it->second;
	overuse_detectors_.erase(it++);
	} else {
	// Make sure that we trigger an over-use if any of the over-use detectors
	// is detecting over-use.
	if (it->second->detector.State() > bw_state) {
	bw_state = it->second->detector.State();
	}
	++it;
	}
	}
	// We can't update the estimate if we don't have any active streams.
	if (overuse_detectors_.empty()) {
	return;
	}
	AimdRateControl* remote_rate = GetRemoteRate();

	const RateControlInput input(
	bw_state, OptionalRateFromOptionalBps(incoming_bitrate_.Rate(now_ms)));
	uint32_t target_bitrate =
	remote_rate->Update(&input, Timestamp::Millis(now_ms)).bps<uint32_t>();
	if (remote_rate->ValidEstimate()) {
	process_interval_ms_ = remote_rate->GetFeedbackInterval().ms();
	RTC_DCHECK_GT(process_interval_ms_, 0);
	std::vector<uint32_t> ssrcs;
	GetSsrcs(&ssrcs);
	if (observer_)
	observer_->OnReceiveBitrateChanged(ssrcs, target_bitrate);
	}
	}

	void RemoteBitrateEstimatorSingleStream::OnRttUpdate(int64_t avg_rtt_ms,
	int64_t max_rtt_ms) {
	MutexLock lock(&mutex_);
	GetRemoteRate()->SetRtt(TimeDelta::Millis(avg_rtt_ms));
	}

	void RemoteBitrateEstimatorSingleStream::RemoveStream(unsigned int ssrc) {
	MutexLock lock(&mutex_);
	SsrcOveruseEstimatorMap::iterator it = overuse_detectors_.find(ssrc);
	if (it != overuse_detectors_.end()) {
	delete it->second;
	overuse_detectors_.erase(it);
	}
	}

	bool RemoteBitrateEstimatorSingleStream::LatestEstimate(
	std::vector<uint32_t>* ssrcs,
	uint32_t* bitrate_bps) const {
	MutexLock lock(&mutex_);
	RTC_DCHECK(bitrate_bps);
	if (!remote_rate_->ValidEstimate()) {
	return false;
	}
	GetSsrcs(ssrcs);
	if (ssrcs->empty())
	*bitrate_bps = 0;
	else
	*bitrate_bps = remote_rate_->LatestEstimate().bps<uint32_t>();
	return true;
	}

	void RemoteBitrateEstimatorSingleStream::GetSsrcs(
	std::vector<uint32_t>* ssrcs) const {
	RTC_DCHECK(ssrcs);
	ssrcs->resize(overuse_detectors_.size());
	int i = 0;
	for (SsrcOveruseEstimatorMap::const_iterator it = overuse_detectors_.begin();
	it != overuse_detectors_.end(); ++it, ++i) {
	(*ssrcs)[i] = it->first;
	}
	}

	AimdRateControl* RemoteBitrateEstimatorSingleStream::GetRemoteRate() {
	if (!remote_rate_)
	remote_rate_.reset(new AimdRateControl(&field_trials_));
	return remote_rate_.get();
	}

	void RemoteBitrateEstimatorSingleStream::SetMinBitrate(int min_bitrate_bps) {
	MutexLock lock(&mutex_);
	remote_rate_->SetMinBitrate(DataRate::BitsPerSec(min_bitrate_bps));
	}

	} // namespace webrtc