webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_single_stream.cc - platform/external/webrtc - 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 <map>

 #include "webrtc/modules/remote_bitrate_estimator/rate_statistics.h"
 #include "webrtc/modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
 #include "webrtc/modules/remote_bitrate_estimator/overuse_detector.h"
 #include "webrtc/modules/remote_bitrate_estimator/remote_rate_control.h"
 #include "webrtc/system_wrappers/interface/clock.h"
 #include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
 #include "webrtc/system_wrappers/interface/logging.h"
 #include "webrtc/system_wrappers/interface/scoped_ptr.h"
 #include "webrtc/typedefs.h"

 namespace webrtc {
 namespace {
 class RemoteBitrateEstimatorSingleStream : public RemoteBitrateEstimator {
  public:
   RemoteBitrateEstimatorSingleStream(RemoteBitrateObserver* observer,
                                      Clock* clock,
                                      uint32_t min_bitrate_bps);
   virtual ~RemoteBitrateEstimatorSingleStream() {}

   // Called for each incoming packet. If this is a new SSRC, a new
   // BitrateControl will be created. Updates the incoming payload bitrate
   // estimate and the over-use detector. If an over-use is detected the
   // remote bitrate estimate will be updated. Note that |payload_size| is the
   // packet size excluding headers.
   virtual void IncomingPacket(int64_t arrival_time_ms,
                               int payload_size,
                               const RTPHeader& header) OVERRIDE;

   // Triggers a new estimate calculation.
   // Implements the Module interface.
   virtual int32_t Process() OVERRIDE;
   virtual int32_t TimeUntilNextProcess() OVERRIDE;
   // Set the current round-trip time experienced by the stream.
   // Implements the StatsObserver interface.
   virtual void OnRttUpdate(uint32_t rtt) OVERRIDE;

   // Removes all data for |ssrc|.
   virtual void RemoveStream(unsigned int ssrc) OVERRIDE;

   // Returns true if a valid estimate exists and sets |bitrate_bps| to the
   // estimated payload bitrate in bits per second. |ssrcs| is the list of ssrcs
   // currently being received and of which the bitrate estimate is based upon.
   virtual bool LatestEstimate(std::vector<unsigned int>* ssrcs,
                               unsigned int* bitrate_bps) const OVERRIDE;

   virtual bool GetStats(
       ReceiveBandwidthEstimatorStats* output) const OVERRIDE;

  private:
   typedef std::map<unsigned int, OveruseDetector> SsrcOveruseDetectorMap;

   // Triggers a new estimate calculation.
   void UpdateEstimate(int64_t time_now);

   void GetSsrcs(std::vector<unsigned int>* ssrcs) const;

   Clock* clock_;
   SsrcOveruseDetectorMap overuse_detectors_;
   RateStatistics incoming_bitrate_;
   RemoteRateControl remote_rate_;
   RemoteBitrateObserver* observer_;
   scoped_ptr<CriticalSectionWrapper> crit_sect_;
   int64_t last_process_time_;
 };

 RemoteBitrateEstimatorSingleStream::RemoteBitrateEstimatorSingleStream(
     RemoteBitrateObserver* observer,
     Clock* clock,
     uint32_t min_bitrate_bps)
     : clock_(clock),
       incoming_bitrate_(500, 8000),
       remote_rate_(min_bitrate_bps),
       observer_(observer),
       crit_sect_(CriticalSectionWrapper::CreateCriticalSection()),
       last_process_time_(-1) {
   assert(observer_);
 }

 void RemoteBitrateEstimatorSingleStream::IncomingPacket(
     int64_t arrival_time_ms,
     int payload_size,
     const RTPHeader& header) {
   uint32_t ssrc = header.ssrc;
   uint32_t rtp_timestamp = header.timestamp +
       header.extension.transmissionTimeOffset;
   CriticalSectionScoped cs(crit_sect_.get());
   SsrcOveruseDetectorMap::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<SsrcOveruseDetectorMap::iterator, bool> insert_result =
         overuse_detectors_.insert(std::make_pair(ssrc, OveruseDetector(
             OverUseDetectorOptions())));
     it = insert_result.first;
   }
   OveruseDetector* overuse_detector = &it->second;
   incoming_bitrate_.Update(payload_size, arrival_time_ms);
   const BandwidthUsage prior_state = overuse_detector->State();
   overuse_detector->Update(payload_size, -1, rtp_timestamp, arrival_time_ms);
   if (overuse_detector->State() == kBwOverusing) {
     unsigned int incoming_bitrate = incoming_bitrate_.Rate(arrival_time_ms);
     if (prior_state != kBwOverusing ||
         remote_rate_.TimeToReduceFurther(arrival_time_ms, incoming_bitrate)) {
       // 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(arrival_time_ms);
     }
   }
 }

 int32_t RemoteBitrateEstimatorSingleStream::Process() {
   if (TimeUntilNextProcess() > 0) {
     return 0;
   }
   UpdateEstimate(clock_->TimeInMilliseconds());
   last_process_time_ = clock_->TimeInMilliseconds();
   return 0;
 }

 int32_t RemoteBitrateEstimatorSingleStream::TimeUntilNextProcess() {
   if (last_process_time_ < 0) {
     return 0;
   }
   return last_process_time_ + kProcessIntervalMs - clock_->TimeInMilliseconds();
 }

 void RemoteBitrateEstimatorSingleStream::UpdateEstimate(int64_t time_now) {
   CriticalSectionScoped cs(crit_sect_.get());
   BandwidthUsage bw_state = kBwNormal;
   double sum_noise_var = 0.0;
   SsrcOveruseDetectorMap::iterator it = overuse_detectors_.begin();
   while (it != overuse_detectors_.end()) {
     const int64_t time_of_last_received_packet =
          it->second.time_of_last_received_packet();
     if (time_of_last_received_packet >= 0 &&
         time_now - time_of_last_received_packet > kStreamTimeOutMs) {
       // This over-use detector hasn't received packets for |kStreamTimeOutMs|
       // milliseconds and is considered stale.
       overuse_detectors_.erase(it++);
     } else {
       sum_noise_var += it->second.NoiseVar();
       // Make sure that we trigger an over-use if any of the over-use detectors
       // is detecting over-use.
       if (it->second.State() > bw_state) {
         bw_state = it->second.State();
       }
       ++it;
     }
   }
   // We can't update the estimate if we don't have any active streams.
   if (overuse_detectors_.empty()) {
     remote_rate_.Reset();
     return;
   }
   double mean_noise_var = sum_noise_var /
       static_cast<double>(overuse_detectors_.size());
   const RateControlInput input(bw_state,
                                incoming_bitrate_.Rate(time_now),
                                mean_noise_var);
   const RateControlRegion region = remote_rate_.Update(&input, time_now);
   unsigned int target_bitrate = remote_rate_.UpdateBandwidthEstimate(time_now);
   if (remote_rate_.ValidEstimate()) {
     std::vector<unsigned int> ssrcs;
     GetSsrcs(&ssrcs);
     observer_->OnReceiveBitrateChanged(ssrcs, target_bitrate);
   }
   for (it = overuse_detectors_.begin(); it != overuse_detectors_.end(); ++it) {
     it->second.SetRateControlRegion(region);
   }
 }

 void RemoteBitrateEstimatorSingleStream::OnRttUpdate(uint32_t rtt) {
   CriticalSectionScoped cs(crit_sect_.get());
   remote_rate_.SetRtt(rtt);
 }

 void RemoteBitrateEstimatorSingleStream::RemoveStream(unsigned int ssrc) {
   CriticalSectionScoped cs(crit_sect_.get());
   // Ignoring the return value which is the number of elements erased.
   overuse_detectors_.erase(ssrc);
 }

 bool RemoteBitrateEstimatorSingleStream::LatestEstimate(
     std::vector<unsigned int>* ssrcs,
     unsigned int* bitrate_bps) const {
   CriticalSectionScoped cs(crit_sect_.get());
   assert(bitrate_bps);
   if (!remote_rate_.ValidEstimate()) {
     return false;
   }
   GetSsrcs(ssrcs);
   if (ssrcs->empty())
     *bitrate_bps = 0;
   else
     *bitrate_bps = remote_rate_.LatestEstimate();
   return true;
 }

 bool RemoteBitrateEstimatorSingleStream::GetStats(
     ReceiveBandwidthEstimatorStats* output) const {
   // Not implemented.
   return false;
 }

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

 RemoteBitrateEstimator* RemoteBitrateEstimatorFactory::Create(
     RemoteBitrateObserver* observer,
     Clock* clock,
     RateControlType control_type,
     uint32_t min_bitrate_bps) const {
   LOG(LS_INFO) << "RemoteBitrateEstimatorFactory: Instantiating.";
   return new RemoteBitrateEstimatorSingleStream(observer, clock,
                                                 min_bitrate_bps);
 }

 RemoteBitrateEstimator* AbsoluteSendTimeRemoteBitrateEstimatorFactory::Create(
     RemoteBitrateObserver* observer,
     Clock* clock,
     RateControlType control_type,
     uint32_t min_bitrate_bps) const {
   LOG(LS_INFO) << "AbsoluteSendTimeRemoteBitrateEstimatorFactory: "
       "Instantiating.";
   return new RemoteBitrateEstimatorSingleStream(observer, clock,
                                                 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 <map>

	#include "webrtc/modules/remote_bitrate_estimator/rate_statistics.h"
	#include "webrtc/modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
	#include "webrtc/modules/remote_bitrate_estimator/overuse_detector.h"
	#include "webrtc/modules/remote_bitrate_estimator/remote_rate_control.h"
	#include "webrtc/system_wrappers/interface/clock.h"
	#include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
	#include "webrtc/system_wrappers/interface/logging.h"
	#include "webrtc/system_wrappers/interface/scoped_ptr.h"
	#include "webrtc/typedefs.h"

	namespace webrtc {
	namespace {
	class RemoteBitrateEstimatorSingleStream : public RemoteBitrateEstimator {
	public:
	RemoteBitrateEstimatorSingleStream(RemoteBitrateObserver* observer,
	Clock* clock,
	uint32_t min_bitrate_bps);
	virtual ~RemoteBitrateEstimatorSingleStream() {}

	// Called for each incoming packet. If this is a new SSRC, a new
	// BitrateControl will be created. Updates the incoming payload bitrate
	// estimate and the over-use detector. If an over-use is detected the
	// remote bitrate estimate will be updated. Note that \|payload_size\| is the
	// packet size excluding headers.
	virtual void IncomingPacket(int64_t arrival_time_ms,
	int payload_size,
	const RTPHeader& header) OVERRIDE;

	// Triggers a new estimate calculation.
	// Implements the Module interface.
	virtual int32_t Process() OVERRIDE;
	virtual int32_t TimeUntilNextProcess() OVERRIDE;
	// Set the current round-trip time experienced by the stream.
	// Implements the StatsObserver interface.
	virtual void OnRttUpdate(uint32_t rtt) OVERRIDE;

	// Removes all data for \|ssrc\|.
	virtual void RemoveStream(unsigned int ssrc) OVERRIDE;

	// Returns true if a valid estimate exists and sets \|bitrate_bps\| to the
	// estimated payload bitrate in bits per second. \|ssrcs\| is the list of ssrcs
	// currently being received and of which the bitrate estimate is based upon.
	virtual bool LatestEstimate(std::vector<unsigned int>* ssrcs,
	unsigned int* bitrate_bps) const OVERRIDE;

	virtual bool GetStats(
	ReceiveBandwidthEstimatorStats* output) const OVERRIDE;

	private:
	typedef std::map<unsigned int, OveruseDetector> SsrcOveruseDetectorMap;

	// Triggers a new estimate calculation.
	void UpdateEstimate(int64_t time_now);

	void GetSsrcs(std::vector<unsigned int>* ssrcs) const;

	Clock* clock_;
	SsrcOveruseDetectorMap overuse_detectors_;
	RateStatistics incoming_bitrate_;
	RemoteRateControl remote_rate_;
	RemoteBitrateObserver* observer_;
	scoped_ptr<CriticalSectionWrapper> crit_sect_;
	int64_t last_process_time_;
	};

	RemoteBitrateEstimatorSingleStream::RemoteBitrateEstimatorSingleStream(
	RemoteBitrateObserver* observer,
	Clock* clock,
	uint32_t min_bitrate_bps)
	: clock_(clock),
	incoming_bitrate_(500, 8000),
	remote_rate_(min_bitrate_bps),
	observer_(observer),
	crit_sect_(CriticalSectionWrapper::CreateCriticalSection()),
	last_process_time_(-1) {
	assert(observer_);
	}

	void RemoteBitrateEstimatorSingleStream::IncomingPacket(
	int64_t arrival_time_ms,
	int payload_size,
	const RTPHeader& header) {
	uint32_t ssrc = header.ssrc;
	uint32_t rtp_timestamp = header.timestamp +
	header.extension.transmissionTimeOffset;
	CriticalSectionScoped cs(crit_sect_.get());
	SsrcOveruseDetectorMap::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<SsrcOveruseDetectorMap::iterator, bool> insert_result =
	overuse_detectors_.insert(std::make_pair(ssrc, OveruseDetector(
	OverUseDetectorOptions())));
	it = insert_result.first;
	}
	OveruseDetector* overuse_detector = &it->second;
	incoming_bitrate_.Update(payload_size, arrival_time_ms);
	const BandwidthUsage prior_state = overuse_detector->State();
	overuse_detector->Update(payload_size, -1, rtp_timestamp, arrival_time_ms);
	if (overuse_detector->State() == kBwOverusing) {
	unsigned int incoming_bitrate = incoming_bitrate_.Rate(arrival_time_ms);
	if (prior_state != kBwOverusing \|\|
	remote_rate_.TimeToReduceFurther(arrival_time_ms, incoming_bitrate)) {
	// 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(arrival_time_ms);
	}
	}
	}

	int32_t RemoteBitrateEstimatorSingleStream::Process() {
	if (TimeUntilNextProcess() > 0) {
	return 0;
	}
	UpdateEstimate(clock_->TimeInMilliseconds());
	last_process_time_ = clock_->TimeInMilliseconds();
	return 0;
	}

	int32_t RemoteBitrateEstimatorSingleStream::TimeUntilNextProcess() {
	if (last_process_time_ < 0) {
	return 0;
	}
	return last_process_time_ + kProcessIntervalMs - clock_->TimeInMilliseconds();
	}

	void RemoteBitrateEstimatorSingleStream::UpdateEstimate(int64_t time_now) {
	CriticalSectionScoped cs(crit_sect_.get());
	BandwidthUsage bw_state = kBwNormal;
	double sum_noise_var = 0.0;
	SsrcOveruseDetectorMap::iterator it = overuse_detectors_.begin();
	while (it != overuse_detectors_.end()) {
	const int64_t time_of_last_received_packet =
	it->second.time_of_last_received_packet();
	if (time_of_last_received_packet >= 0 &&
	time_now - time_of_last_received_packet > kStreamTimeOutMs) {
	// This over-use detector hasn't received packets for \|kStreamTimeOutMs\|
	// milliseconds and is considered stale.
	overuse_detectors_.erase(it++);
	} else {
	sum_noise_var += it->second.NoiseVar();
	// Make sure that we trigger an over-use if any of the over-use detectors
	// is detecting over-use.
	if (it->second.State() > bw_state) {
	bw_state = it->second.State();
	}
	++it;
	}
	}
	// We can't update the estimate if we don't have any active streams.
	if (overuse_detectors_.empty()) {
	remote_rate_.Reset();
	return;
	}
	double mean_noise_var = sum_noise_var /
	static_cast<double>(overuse_detectors_.size());
	const RateControlInput input(bw_state,
	incoming_bitrate_.Rate(time_now),
	mean_noise_var);
	const RateControlRegion region = remote_rate_.Update(&input, time_now);
	unsigned int target_bitrate = remote_rate_.UpdateBandwidthEstimate(time_now);
	if (remote_rate_.ValidEstimate()) {
	std::vector<unsigned int> ssrcs;
	GetSsrcs(&ssrcs);
	observer_->OnReceiveBitrateChanged(ssrcs, target_bitrate);
	}
	for (it = overuse_detectors_.begin(); it != overuse_detectors_.end(); ++it) {
	it->second.SetRateControlRegion(region);
	}
	}

	void RemoteBitrateEstimatorSingleStream::OnRttUpdate(uint32_t rtt) {
	CriticalSectionScoped cs(crit_sect_.get());
	remote_rate_.SetRtt(rtt);
	}

	void RemoteBitrateEstimatorSingleStream::RemoveStream(unsigned int ssrc) {
	CriticalSectionScoped cs(crit_sect_.get());
	// Ignoring the return value which is the number of elements erased.
	overuse_detectors_.erase(ssrc);
	}

	bool RemoteBitrateEstimatorSingleStream::LatestEstimate(
	std::vector<unsigned int>* ssrcs,
	unsigned int* bitrate_bps) const {
	CriticalSectionScoped cs(crit_sect_.get());
	assert(bitrate_bps);
	if (!remote_rate_.ValidEstimate()) {
	return false;
	}
	GetSsrcs(ssrcs);
	if (ssrcs->empty())
	*bitrate_bps = 0;
	else
	*bitrate_bps = remote_rate_.LatestEstimate();
	return true;
	}

	bool RemoteBitrateEstimatorSingleStream::GetStats(
	ReceiveBandwidthEstimatorStats* output) const {
	// Not implemented.
	return false;
	}

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

	RemoteBitrateEstimator* RemoteBitrateEstimatorFactory::Create(
	RemoteBitrateObserver* observer,
	Clock* clock,
	RateControlType control_type,
	uint32_t min_bitrate_bps) const {
	LOG(LS_INFO) << "RemoteBitrateEstimatorFactory: Instantiating.";
	return new RemoteBitrateEstimatorSingleStream(observer, clock,
	min_bitrate_bps);
	}

	RemoteBitrateEstimator* AbsoluteSendTimeRemoteBitrateEstimatorFactory::Create(
	RemoteBitrateObserver* observer,
	Clock* clock,
	RateControlType control_type,
	uint32_t min_bitrate_bps) const {
	LOG(LS_INFO) << "AbsoluteSendTimeRemoteBitrateEstimatorFactory: "
	"Instantiating.";
	return new RemoteBitrateEstimatorSingleStream(observer, clock,
	min_bitrate_bps);
	}
	} // namespace webrtc