modules/congestion_controller/rtp/transport_feedback_adapter.cc - src - Git at Google

 /*
  *  Copyright (c) 2015 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/rtp/transport_feedback_adapter.h"

 #include <stdlib.h>
 #include <algorithm>
 #include <cmath>

 #include "api/units/timestamp.h"
 #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"

 namespace webrtc {
 namespace {

 PacketResult NetworkPacketFeedbackFromRtpPacketFeedback(
     const webrtc::PacketFeedback& pf) {
   PacketResult feedback;
   if (pf.arrival_time_ms == webrtc::PacketFeedback::kNotReceived) {
     feedback.receive_time = Timestamp::PlusInfinity();
   } else {
     feedback.receive_time = Timestamp::ms(pf.arrival_time_ms);
   }
   feedback.sent_packet.sequence_number = pf.long_sequence_number;
   feedback.sent_packet.send_time = Timestamp::ms(pf.send_time_ms);
   feedback.sent_packet.size = DataSize::bytes(pf.payload_size);
   feedback.sent_packet.pacing_info = pf.pacing_info;
   feedback.sent_packet.prior_unacked_data =
       DataSize::bytes(pf.unacknowledged_data);
   return feedback;
 }
 }  // namespace
 const int64_t kNoTimestamp = -1;
 const int64_t kSendTimeHistoryWindowMs = 60000;
 const int64_t kBaseTimestampScaleFactor =
     rtcp::TransportFeedback::kDeltaScaleFactor * (1 << 8);
 const int64_t kBaseTimestampRangeSizeUs = kBaseTimestampScaleFactor * (1 << 24);

 TransportFeedbackAdapter::TransportFeedbackAdapter()
     : send_time_history_(kSendTimeHistoryWindowMs),
       current_offset_ms_(kNoTimestamp),
       last_timestamp_us_(kNoTimestamp),
       local_net_id_(0),
       remote_net_id_(0) {}

 TransportFeedbackAdapter::~TransportFeedbackAdapter() {
   RTC_DCHECK(observers_.empty());
 }

 void TransportFeedbackAdapter::RegisterPacketFeedbackObserver(
     PacketFeedbackObserver* observer) {
   rtc::CritScope cs(&observers_lock_);
   RTC_DCHECK(observer);
   RTC_DCHECK(std::find(observers_.begin(), observers_.end(), observer) ==
              observers_.end());
   observers_.push_back(observer);
 }

 void TransportFeedbackAdapter::DeRegisterPacketFeedbackObserver(
     PacketFeedbackObserver* observer) {
   rtc::CritScope cs(&observers_lock_);
   RTC_DCHECK(observer);
   const auto it = std::find(observers_.begin(), observers_.end(), observer);
   RTC_DCHECK(it != observers_.end());
   observers_.erase(it);
 }

 void TransportFeedbackAdapter::AddPacket(uint32_t ssrc,
                                          uint16_t sequence_number,
                                          size_t length,
                                          const PacedPacketInfo& pacing_info,
                                          Timestamp creation_time) {
   {
     rtc::CritScope cs(&lock_);
     send_time_history_.AddAndRemoveOld(
         PacketFeedback(creation_time.ms(), sequence_number, length,
                        local_net_id_, remote_net_id_, pacing_info),
         creation_time.ms());
   }

   {
     rtc::CritScope cs(&observers_lock_);
     for (auto* observer : observers_) {
       observer->OnPacketAdded(ssrc, sequence_number);
     }
   }
 }
 absl::optional<SentPacket> TransportFeedbackAdapter::ProcessSentPacket(
     const rtc::SentPacket& sent_packet) {
   rtc::CritScope cs(&lock_);
   // TODO(srte): Only use one way to indicate that packet feedback is used.
   if (sent_packet.info.included_in_feedback || sent_packet.packet_id != -1) {
     send_time_history_.OnSentPacket(sent_packet.packet_id,
                                     sent_packet.send_time_ms);
     absl::optional<PacketFeedback> packet =
         send_time_history_.GetPacket(sent_packet.packet_id);
     if (packet) {
       SentPacket msg;
       msg.size = DataSize::bytes(packet->payload_size);
       msg.send_time = Timestamp::ms(packet->send_time_ms);
       msg.sequence_number = packet->long_sequence_number;
       msg.prior_unacked_data = DataSize::bytes(packet->unacknowledged_data);
       msg.data_in_flight =
           send_time_history_.GetOutstandingData(local_net_id_, remote_net_id_);
       return msg;
     }
   } else if (sent_packet.info.included_in_allocation) {
     send_time_history_.AddUntracked(sent_packet.info.packet_size_bytes,
                                     sent_packet.send_time_ms);
   }
   return absl::nullopt;
 }

 absl::optional<TransportPacketsFeedback>
 TransportFeedbackAdapter::ProcessTransportFeedback(
     const rtcp::TransportFeedback& feedback,
     Timestamp feedback_receive_time) {
   DataSize prior_in_flight = GetOutstandingData();

   last_packet_feedback_vector_ =
       GetPacketFeedbackVector(feedback, feedback_receive_time);
   {
     rtc::CritScope cs(&observers_lock_);
     for (auto* observer : observers_) {
       observer->OnPacketFeedbackVector(last_packet_feedback_vector_);
     }
   }

   std::vector<PacketFeedback> feedback_vector = last_packet_feedback_vector_;
   if (feedback_vector.empty())
     return absl::nullopt;

   TransportPacketsFeedback msg;
   for (const PacketFeedback& rtp_feedback : feedback_vector) {
     if (rtp_feedback.send_time_ms != PacketFeedback::kNoSendTime) {
       auto feedback = NetworkPacketFeedbackFromRtpPacketFeedback(rtp_feedback);
       msg.packet_feedbacks.push_back(feedback);
     } else if (rtp_feedback.arrival_time_ms == PacketFeedback::kNotReceived) {
       msg.sendless_arrival_times.push_back(Timestamp::PlusInfinity());
     } else {
       msg.sendless_arrival_times.push_back(
           Timestamp::ms(rtp_feedback.arrival_time_ms));
     }
   }
   {
     rtc::CritScope cs(&lock_);
     absl::optional<int64_t> first_unacked_send_time_ms =
         send_time_history_.GetFirstUnackedSendTime();
     if (first_unacked_send_time_ms)
       msg.first_unacked_send_time = Timestamp::ms(*first_unacked_send_time_ms);
   }
   msg.feedback_time = feedback_receive_time;
   msg.prior_in_flight = prior_in_flight;
   msg.data_in_flight = GetOutstandingData();
   return msg;
 }

 void TransportFeedbackAdapter::SetNetworkIds(uint16_t local_id,
                                              uint16_t remote_id) {
   rtc::CritScope cs(&lock_);
   local_net_id_ = local_id;
   remote_net_id_ = remote_id;
 }

 DataSize TransportFeedbackAdapter::GetOutstandingData() const {
   rtc::CritScope cs(&lock_);
   return send_time_history_.GetOutstandingData(local_net_id_, remote_net_id_);
 }

 std::vector<PacketFeedback> TransportFeedbackAdapter::GetPacketFeedbackVector(
     const rtcp::TransportFeedback& feedback,
     Timestamp feedback_time) {
   int64_t timestamp_us = feedback.GetBaseTimeUs();

   // Add timestamp deltas to a local time base selected on first packet arrival.
   // This won't be the true time base, but makes it easier to manually inspect
   // time stamps.
   if (last_timestamp_us_ == kNoTimestamp) {
     current_offset_ms_ = feedback_time.ms();
   } else {
     int64_t delta = timestamp_us - last_timestamp_us_;

     // Detect and compensate for wrap-arounds in base time.
     if (std::abs(delta - kBaseTimestampRangeSizeUs) < std::abs(delta)) {
       delta -= kBaseTimestampRangeSizeUs;  // Wrap backwards.
     } else if (std::abs(delta + kBaseTimestampRangeSizeUs) < std::abs(delta)) {
       delta += kBaseTimestampRangeSizeUs;  // Wrap forwards.
     }

     current_offset_ms_ += delta / 1000;
   }
   last_timestamp_us_ = timestamp_us;

   std::vector<PacketFeedback> packet_feedback_vector;
   if (feedback.GetPacketStatusCount() == 0) {
     RTC_LOG(LS_INFO) << "Empty transport feedback packet received.";
     return packet_feedback_vector;
   }
   packet_feedback_vector.reserve(feedback.GetPacketStatusCount());
   {
     rtc::CritScope cs(&lock_);
     size_t failed_lookups = 0;
     int64_t offset_us = 0;
     int64_t timestamp_ms = 0;
     uint16_t seq_num = feedback.GetBaseSequence();
     for (const auto& packet : feedback.GetReceivedPackets()) {
       // Insert into the vector those unreceived packets which precede this
       // iteration's received packet.
       for (; seq_num != packet.sequence_number(); ++seq_num) {
         PacketFeedback packet_feedback(PacketFeedback::kNotReceived, seq_num);
         // Note: Element not removed from history because it might be reported
         // as received by another feedback.
         if (!send_time_history_.GetFeedback(&packet_feedback, false))
           ++failed_lookups;
         if (packet_feedback.local_net_id == local_net_id_ &&
             packet_feedback.remote_net_id == remote_net_id_) {
           packet_feedback_vector.push_back(packet_feedback);
         }
       }

       // Handle this iteration's received packet.
       offset_us += packet.delta_us();
       timestamp_ms = current_offset_ms_ + (offset_us / 1000);
       PacketFeedback packet_feedback(timestamp_ms, packet.sequence_number());
       if (!send_time_history_.GetFeedback(&packet_feedback, true))
         ++failed_lookups;
       if (packet_feedback.local_net_id == local_net_id_ &&
           packet_feedback.remote_net_id == remote_net_id_) {
         packet_feedback_vector.push_back(packet_feedback);
       }

       ++seq_num;
     }

     if (failed_lookups > 0) {
       RTC_LOG(LS_WARNING) << "Failed to lookup send time for " << failed_lookups
                           << " packet" << (failed_lookups > 1 ? "s" : "")
                           << ". Send time history too small?";
     }
   }
   return packet_feedback_vector;
 }

 std::vector<PacketFeedback>
 TransportFeedbackAdapter::GetTransportFeedbackVector() const {
   return last_packet_feedback_vector_;
 }

 }  // namespace webrtc
	/*
	* Copyright (c) 2015 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/rtp/transport_feedback_adapter.h"

	#include <stdlib.h>
	#include <algorithm>
	#include <cmath>

	#include "api/units/timestamp.h"
	#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
	#include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
	#include "rtc_base/checks.h"
	#include "rtc_base/logging.h"

	namespace webrtc {
	namespace {

	PacketResult NetworkPacketFeedbackFromRtpPacketFeedback(
	const webrtc::PacketFeedback& pf) {
	PacketResult feedback;
	if (pf.arrival_time_ms == webrtc::PacketFeedback::kNotReceived) {
	feedback.receive_time = Timestamp::PlusInfinity();
	} else {
	feedback.receive_time = Timestamp::ms(pf.arrival_time_ms);
	}
	feedback.sent_packet.sequence_number = pf.long_sequence_number;
	feedback.sent_packet.send_time = Timestamp::ms(pf.send_time_ms);
	feedback.sent_packet.size = DataSize::bytes(pf.payload_size);
	feedback.sent_packet.pacing_info = pf.pacing_info;
	feedback.sent_packet.prior_unacked_data =
	DataSize::bytes(pf.unacknowledged_data);
	return feedback;
	}
	} // namespace
	const int64_t kNoTimestamp = -1;
	const int64_t kSendTimeHistoryWindowMs = 60000;
	const int64_t kBaseTimestampScaleFactor =
	rtcp::TransportFeedback::kDeltaScaleFactor * (1 << 8);
	const int64_t kBaseTimestampRangeSizeUs = kBaseTimestampScaleFactor * (1 << 24);

	TransportFeedbackAdapter::TransportFeedbackAdapter()
	: send_time_history_(kSendTimeHistoryWindowMs),
	current_offset_ms_(kNoTimestamp),
	last_timestamp_us_(kNoTimestamp),
	local_net_id_(0),
	remote_net_id_(0) {}

	TransportFeedbackAdapter::~TransportFeedbackAdapter() {
	RTC_DCHECK(observers_.empty());
	}

	void TransportFeedbackAdapter::RegisterPacketFeedbackObserver(
	PacketFeedbackObserver* observer) {
	rtc::CritScope cs(&observers_lock_);
	RTC_DCHECK(observer);
	RTC_DCHECK(std::find(observers_.begin(), observers_.end(), observer) ==
	observers_.end());
	observers_.push_back(observer);
	}

	void TransportFeedbackAdapter::DeRegisterPacketFeedbackObserver(
	PacketFeedbackObserver* observer) {
	rtc::CritScope cs(&observers_lock_);
	RTC_DCHECK(observer);
	const auto it = std::find(observers_.begin(), observers_.end(), observer);
	RTC_DCHECK(it != observers_.end());
	observers_.erase(it);
	}

	void TransportFeedbackAdapter::AddPacket(uint32_t ssrc,
	uint16_t sequence_number,
	size_t length,
	const PacedPacketInfo& pacing_info,
	Timestamp creation_time) {
	{
	rtc::CritScope cs(&lock_);
	send_time_history_.AddAndRemoveOld(
	PacketFeedback(creation_time.ms(), sequence_number, length,
	local_net_id_, remote_net_id_, pacing_info),
	creation_time.ms());
	}

	{
	rtc::CritScope cs(&observers_lock_);
	for (auto* observer : observers_) {
	observer->OnPacketAdded(ssrc, sequence_number);
	}
	}
	}
	absl::optional<SentPacket> TransportFeedbackAdapter::ProcessSentPacket(
	const rtc::SentPacket& sent_packet) {
	rtc::CritScope cs(&lock_);
	// TODO(srte): Only use one way to indicate that packet feedback is used.
	if (sent_packet.info.included_in_feedback \|\| sent_packet.packet_id != -1) {
	send_time_history_.OnSentPacket(sent_packet.packet_id,
	sent_packet.send_time_ms);
	absl::optional<PacketFeedback> packet =
	send_time_history_.GetPacket(sent_packet.packet_id);
	if (packet) {
	SentPacket msg;
	msg.size = DataSize::bytes(packet->payload_size);
	msg.send_time = Timestamp::ms(packet->send_time_ms);
	msg.sequence_number = packet->long_sequence_number;
	msg.prior_unacked_data = DataSize::bytes(packet->unacknowledged_data);
	msg.data_in_flight =
	send_time_history_.GetOutstandingData(local_net_id_, remote_net_id_);
	return msg;
	}
	} else if (sent_packet.info.included_in_allocation) {
	send_time_history_.AddUntracked(sent_packet.info.packet_size_bytes,
	sent_packet.send_time_ms);
	}
	return absl::nullopt;
	}

	absl::optional<TransportPacketsFeedback>
	TransportFeedbackAdapter::ProcessTransportFeedback(
	const rtcp::TransportFeedback& feedback,
	Timestamp feedback_receive_time) {
	DataSize prior_in_flight = GetOutstandingData();

	last_packet_feedback_vector_ =
	GetPacketFeedbackVector(feedback, feedback_receive_time);
	{
	rtc::CritScope cs(&observers_lock_);
	for (auto* observer : observers_) {
	observer->OnPacketFeedbackVector(last_packet_feedback_vector_);
	}
	}

	std::vector<PacketFeedback> feedback_vector = last_packet_feedback_vector_;
	if (feedback_vector.empty())
	return absl::nullopt;

	TransportPacketsFeedback msg;
	for (const PacketFeedback& rtp_feedback : feedback_vector) {
	if (rtp_feedback.send_time_ms != PacketFeedback::kNoSendTime) {
	auto feedback = NetworkPacketFeedbackFromRtpPacketFeedback(rtp_feedback);
	msg.packet_feedbacks.push_back(feedback);
	} else if (rtp_feedback.arrival_time_ms == PacketFeedback::kNotReceived) {
	msg.sendless_arrival_times.push_back(Timestamp::PlusInfinity());
	} else {
	msg.sendless_arrival_times.push_back(
	Timestamp::ms(rtp_feedback.arrival_time_ms));
	}
	}
	{
	rtc::CritScope cs(&lock_);
	absl::optional<int64_t> first_unacked_send_time_ms =
	send_time_history_.GetFirstUnackedSendTime();
	if (first_unacked_send_time_ms)
	msg.first_unacked_send_time = Timestamp::ms(*first_unacked_send_time_ms);
	}
	msg.feedback_time = feedback_receive_time;
	msg.prior_in_flight = prior_in_flight;
	msg.data_in_flight = GetOutstandingData();
	return msg;
	}

	void TransportFeedbackAdapter::SetNetworkIds(uint16_t local_id,
	uint16_t remote_id) {
	rtc::CritScope cs(&lock_);
	local_net_id_ = local_id;
	remote_net_id_ = remote_id;
	}

	DataSize TransportFeedbackAdapter::GetOutstandingData() const {
	rtc::CritScope cs(&lock_);
	return send_time_history_.GetOutstandingData(local_net_id_, remote_net_id_);
	}

	std::vector<PacketFeedback> TransportFeedbackAdapter::GetPacketFeedbackVector(
	const rtcp::TransportFeedback& feedback,
	Timestamp feedback_time) {
	int64_t timestamp_us = feedback.GetBaseTimeUs();

	// Add timestamp deltas to a local time base selected on first packet arrival.
	// This won't be the true time base, but makes it easier to manually inspect
	// time stamps.
	if (last_timestamp_us_ == kNoTimestamp) {
	current_offset_ms_ = feedback_time.ms();
	} else {
	int64_t delta = timestamp_us - last_timestamp_us_;

	// Detect and compensate for wrap-arounds in base time.
	if (std::abs(delta - kBaseTimestampRangeSizeUs) < std::abs(delta)) {
	delta -= kBaseTimestampRangeSizeUs; // Wrap backwards.
	} else if (std::abs(delta + kBaseTimestampRangeSizeUs) < std::abs(delta)) {
	delta += kBaseTimestampRangeSizeUs; // Wrap forwards.
	}

	current_offset_ms_ += delta / 1000;
	}
	last_timestamp_us_ = timestamp_us;

	std::vector<PacketFeedback> packet_feedback_vector;
	if (feedback.GetPacketStatusCount() == 0) {
	RTC_LOG(LS_INFO) << "Empty transport feedback packet received.";
	return packet_feedback_vector;
	}
	packet_feedback_vector.reserve(feedback.GetPacketStatusCount());
	{
	rtc::CritScope cs(&lock_);
	size_t failed_lookups = 0;
	int64_t offset_us = 0;
	int64_t timestamp_ms = 0;
	uint16_t seq_num = feedback.GetBaseSequence();
	for (const auto& packet : feedback.GetReceivedPackets()) {
	// Insert into the vector those unreceived packets which precede this
	// iteration's received packet.
	for (; seq_num != packet.sequence_number(); ++seq_num) {
	PacketFeedback packet_feedback(PacketFeedback::kNotReceived, seq_num);
	// Note: Element not removed from history because it might be reported
	// as received by another feedback.
	if (!send_time_history_.GetFeedback(&packet_feedback, false))
	++failed_lookups;
	if (packet_feedback.local_net_id == local_net_id_ &&
	packet_feedback.remote_net_id == remote_net_id_) {
	packet_feedback_vector.push_back(packet_feedback);
	}
	}

	// Handle this iteration's received packet.
	offset_us += packet.delta_us();
	timestamp_ms = current_offset_ms_ + (offset_us / 1000);
	PacketFeedback packet_feedback(timestamp_ms, packet.sequence_number());
	if (!send_time_history_.GetFeedback(&packet_feedback, true))
	++failed_lookups;
	if (packet_feedback.local_net_id == local_net_id_ &&
	packet_feedback.remote_net_id == remote_net_id_) {
	packet_feedback_vector.push_back(packet_feedback);
	}

	++seq_num;
	}

	if (failed_lookups > 0) {
	RTC_LOG(LS_WARNING) << "Failed to lookup send time for " << failed_lookups
	<< " packet" << (failed_lookups > 1 ? "s" : "")
	<< ". Send time history too small?";
	}
	}
	return packet_feedback_vector;
	}

	std::vector<PacketFeedback>
	TransportFeedbackAdapter::GetTransportFeedbackVector() const {
	return last_packet_feedback_vector_;
	}

	} // namespace webrtc