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/*
* 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 "webrtc/modules/bitrate_controller/bitrate_controller_impl.h"
#include <algorithm>
#include <utility>
#include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
namespace webrtc {
class BitrateControllerImpl::RtcpBandwidthObserverImpl
: public RtcpBandwidthObserver {
public:
explicit RtcpBandwidthObserverImpl(BitrateControllerImpl* owner)
: owner_(owner) {
}
virtual ~RtcpBandwidthObserverImpl() {
}
// Received RTCP REMB or TMMBR.
void OnReceivedEstimatedBitrate(uint32_t bitrate) override {
owner_->OnReceivedEstimatedBitrate(bitrate);
}
// Received RTCP receiver block.
void OnReceivedRtcpReceiverReport(const ReportBlockList& report_blocks,
int64_t rtt,
int64_t now_ms) override {
if (report_blocks.empty())
return;
int fraction_lost_aggregate = 0;
int total_number_of_packets = 0;
// Compute the a weighted average of the fraction loss from all report
// blocks.
for (ReportBlockList::const_iterator it = report_blocks.begin();
it != report_blocks.end(); ++it) {
std::map<uint32_t, uint32_t>::iterator seq_num_it =
ssrc_to_last_received_extended_high_seq_num_.find(it->sourceSSRC);
int number_of_packets = 0;
if (seq_num_it != ssrc_to_last_received_extended_high_seq_num_.end())
number_of_packets = it->extendedHighSeqNum -
seq_num_it->second;
fraction_lost_aggregate += number_of_packets * it->fractionLost;
total_number_of_packets += number_of_packets;
// Update last received for this SSRC.
ssrc_to_last_received_extended_high_seq_num_[it->sourceSSRC] =
it->extendedHighSeqNum;
}
if (total_number_of_packets == 0)
fraction_lost_aggregate = 0;
else
fraction_lost_aggregate = (fraction_lost_aggregate +
total_number_of_packets / 2) / total_number_of_packets;
if (fraction_lost_aggregate > 255)
return;
owner_->OnReceivedRtcpReceiverReport(fraction_lost_aggregate, rtt,
total_number_of_packets, now_ms);
}
private:
std::map<uint32_t, uint32_t> ssrc_to_last_received_extended_high_seq_num_;
BitrateControllerImpl* owner_;
};
BitrateController* BitrateController::CreateBitrateController(
Clock* clock,
BitrateObserver* observer) {
return new BitrateControllerImpl(clock, observer);
}
BitrateControllerImpl::BitrateControllerImpl(Clock* clock,
BitrateObserver* observer)
: clock_(clock),
observer_(observer),
last_bitrate_update_ms_(clock_->TimeInMilliseconds()),
bandwidth_estimation_(),
reserved_bitrate_bps_(0),
last_bitrate_bps_(0),
last_fraction_loss_(0),
last_rtt_ms_(0),
last_reserved_bitrate_bps_(0) {
// This calls the observer_, which means that the observer provided by the
// user must be ready to accept a bitrate update when it constructs the
// controller. We do this to avoid having to keep synchronized initial values
// in both the controller and the allocator.
MaybeTriggerOnNetworkChanged();
}
RtcpBandwidthObserver* BitrateControllerImpl::CreateRtcpBandwidthObserver() {
return new RtcpBandwidthObserverImpl(this);
}
void BitrateControllerImpl::SetStartBitrate(int start_bitrate_bps) {
{
rtc::CritScope cs(&critsect_);
bandwidth_estimation_.SetSendBitrate(start_bitrate_bps);
}
MaybeTriggerOnNetworkChanged();
}
void BitrateControllerImpl::SetMinMaxBitrate(int min_bitrate_bps,
int max_bitrate_bps) {
{
rtc::CritScope cs(&critsect_);
bandwidth_estimation_.SetMinMaxBitrate(min_bitrate_bps, max_bitrate_bps);
}
MaybeTriggerOnNetworkChanged();
}
void BitrateControllerImpl::SetReservedBitrate(uint32_t reserved_bitrate_bps) {
{
rtc::CritScope cs(&critsect_);
reserved_bitrate_bps_ = reserved_bitrate_bps;
}
MaybeTriggerOnNetworkChanged();
}
void BitrateControllerImpl::SetEventLog(RtcEventLog* event_log) {
rtc::CritScope cs(&critsect_);
bandwidth_estimation_.SetEventLog(event_log);
}
void BitrateControllerImpl::OnReceivedEstimatedBitrate(uint32_t bitrate) {
{
rtc::CritScope cs(&critsect_);
bandwidth_estimation_.UpdateReceiverEstimate(clock_->TimeInMilliseconds(),
bitrate);
}
MaybeTriggerOnNetworkChanged();
}
int64_t BitrateControllerImpl::TimeUntilNextProcess() {
const int64_t kBitrateControllerUpdateIntervalMs = 25;
rtc::CritScope cs(&critsect_);
int64_t time_since_update_ms =
clock_->TimeInMilliseconds() - last_bitrate_update_ms_;
return std::max<int64_t>(
kBitrateControllerUpdateIntervalMs - time_since_update_ms, 0);
}
int32_t BitrateControllerImpl::Process() {
if (TimeUntilNextProcess() > 0)
return 0;
{
rtc::CritScope cs(&critsect_);
bandwidth_estimation_.UpdateEstimate(clock_->TimeInMilliseconds());
}
MaybeTriggerOnNetworkChanged();
last_bitrate_update_ms_ = clock_->TimeInMilliseconds();
return 0;
}
void BitrateControllerImpl::OnReceivedRtcpReceiverReport(
uint8_t fraction_loss,
int64_t rtt,
int number_of_packets,
int64_t now_ms) {
{
rtc::CritScope cs(&critsect_);
bandwidth_estimation_.UpdateReceiverBlock(fraction_loss, rtt,
number_of_packets, now_ms);
}
MaybeTriggerOnNetworkChanged();
}
void BitrateControllerImpl::MaybeTriggerOnNetworkChanged() {
uint32_t bitrate;
uint8_t fraction_loss;
int64_t rtt;
if (GetNetworkParameters(&bitrate, &fraction_loss, &rtt))
observer_->OnNetworkChanged(bitrate, fraction_loss, rtt);
}
bool BitrateControllerImpl::GetNetworkParameters(uint32_t* bitrate,
uint8_t* fraction_loss,
int64_t* rtt) {
rtc::CritScope cs(&critsect_);
int current_bitrate;
bandwidth_estimation_.CurrentEstimate(¤t_bitrate, fraction_loss, rtt);
*bitrate = current_bitrate;
*bitrate -= std::min(*bitrate, reserved_bitrate_bps_);
*bitrate =
std::max<uint32_t>(*bitrate, bandwidth_estimation_.GetMinBitrate());
bool new_bitrate = false;
if (*bitrate != last_bitrate_bps_ || *fraction_loss != last_fraction_loss_ ||
*rtt != last_rtt_ms_ ||
last_reserved_bitrate_bps_ != reserved_bitrate_bps_) {
last_bitrate_bps_ = *bitrate;
last_fraction_loss_ = *fraction_loss;
last_rtt_ms_ = *rtt;
last_reserved_bitrate_bps_ = reserved_bitrate_bps_;
new_bitrate = true;
}
return new_bitrate;
}
bool BitrateControllerImpl::AvailableBandwidth(uint32_t* bandwidth) const {
rtc::CritScope cs(&critsect_);
int bitrate;
uint8_t fraction_loss;
int64_t rtt;
bandwidth_estimation_.CurrentEstimate(&bitrate, &fraction_loss, &rtt);
if (bitrate > 0) {
bitrate = bitrate - std::min<int>(bitrate, reserved_bitrate_bps_);
bitrate = std::max(bitrate, bandwidth_estimation_.GetMinBitrate());
*bandwidth = bitrate;
return true;
}
return false;
}
} // namespace webrtc
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