blob: 7a5f7c4ee3f7a398a24504b2176e3689ce0dac29 [file] [log] [blame]
/*
* 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/transport_feedback_adapter.h"
#include <algorithm>
#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"
#include "rtc_base/numerics/mod_ops.h"
namespace webrtc {
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(const Clock* clock)
: send_time_history_(clock, kSendTimeHistoryWindowMs),
clock_(clock),
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) {
{
rtc::CritScope cs(&lock_);
const int64_t creation_time_ms = clock_->TimeInMilliseconds();
send_time_history_.AddAndRemoveOld(
PacketFeedback(creation_time_ms, sequence_number, length, local_net_id_,
remote_net_id_, pacing_info));
}
{
rtc::CritScope cs(&observers_lock_);
for (auto* observer : observers_) {
observer->OnPacketAdded(ssrc, sequence_number);
}
}
}
void TransportFeedbackAdapter::OnSentPacket(uint16_t sequence_number,
int64_t send_time_ms) {
rtc::CritScope cs(&lock_);
send_time_history_.OnSentPacket(sequence_number, send_time_ms);
}
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;
}
std::vector<PacketFeedback> TransportFeedbackAdapter::GetPacketFeedbackVector(
const rtcp::TransportFeedback& feedback) {
int64_t timestamp_us = feedback.GetBaseTimeUs();
int64_t now_ms = clock_->TimeInMilliseconds();
// 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_ = now_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());
int64_t feedback_rtt = -1;
{
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_) {
if (packet_feedback.send_time_ms >= 0) {
int64_t rtt = now_ms - packet_feedback.send_time_ms;
// max() is used to account for feedback being delayed by the
// receiver.
feedback_rtt = std::max(rtt, feedback_rtt);
}
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?";
}
if (feedback_rtt > -1) {
feedback_rtts_.push_back(feedback_rtt);
const size_t kFeedbackRttWindow = 32;
if (feedback_rtts_.size() > kFeedbackRttWindow)
feedback_rtts_.pop_front();
min_feedback_rtt_.emplace(
*std::min_element(feedback_rtts_.begin(), feedback_rtts_.end()));
}
}
return packet_feedback_vector;
}
void TransportFeedbackAdapter::OnTransportFeedback(
const rtcp::TransportFeedback& feedback) {
last_packet_feedback_vector_ = GetPacketFeedbackVector(feedback);
{
rtc::CritScope cs(&observers_lock_);
for (auto* observer : observers_) {
observer->OnPacketFeedbackVector(last_packet_feedback_vector_);
}
}
}
std::vector<PacketFeedback>
TransportFeedbackAdapter::GetTransportFeedbackVector() const {
return last_packet_feedback_vector_;
}
rtc::Optional<int64_t> TransportFeedbackAdapter::GetMinFeedbackLoopRtt() const {
rtc::CritScope cs(&lock_);
return min_feedback_rtt_;
}
size_t TransportFeedbackAdapter::GetOutstandingBytes() const {
rtc::CritScope cs(&lock_);
return send_time_history_.GetOutstandingBytes(local_net_id_, remote_net_id_);
}
} // namespace webrtc