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/*
* 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 "webrtc/modules/remote_bitrate_estimator/remote_estimator_proxy.h"
#include "webrtc/base/checks.h"
#include "webrtc/base/logging.h"
#include "webrtc/system_wrappers/include/clock.h"
#include "webrtc/modules/pacing/packet_router.h"
#include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
#include "webrtc/modules/rtp_rtcp/include/rtp_rtcp.h"
namespace webrtc {
// TODO(sprang): Tune these!
const int RemoteEstimatorProxy::kDefaultProcessIntervalMs = 50;
const int RemoteEstimatorProxy::kBackWindowMs = 500;
RemoteEstimatorProxy::RemoteEstimatorProxy(Clock* clock,
PacketRouter* packet_router)
: clock_(clock),
packet_router_(packet_router),
last_process_time_ms_(-1),
media_ssrc_(0),
feedback_sequence_(0),
window_start_seq_(-1) {}
RemoteEstimatorProxy::~RemoteEstimatorProxy() {}
void RemoteEstimatorProxy::IncomingPacketFeedbackVector(
const std::vector<PacketInfo>& packet_feedback_vector) {
rtc::CritScope cs(&lock_);
for (PacketInfo info : packet_feedback_vector)
OnPacketArrival(info.sequence_number, info.arrival_time_ms);
}
void RemoteEstimatorProxy::IncomingPacket(int64_t arrival_time_ms,
size_t payload_size,
const RTPHeader& header,
bool was_paced) {
if (!header.extension.hasTransportSequenceNumber) {
LOG(LS_WARNING) << "RemoteEstimatorProxy: Incoming packet "
"is missing the transport sequence number extension!";
return;
}
rtc::CritScope cs(&lock_);
media_ssrc_ = header.ssrc;
OnPacketArrival(header.extension.transportSequenceNumber, arrival_time_ms);
}
void RemoteEstimatorProxy::RemoveStream(unsigned int ssrc) {}
bool RemoteEstimatorProxy::LatestEstimate(std::vector<unsigned int>* ssrcs,
unsigned int* bitrate_bps) const {
return false;
}
bool RemoteEstimatorProxy::GetStats(
ReceiveBandwidthEstimatorStats* output) const {
return false;
}
int64_t RemoteEstimatorProxy::TimeUntilNextProcess() {
int64_t now = clock_->TimeInMilliseconds();
int64_t time_until_next = 0;
if (last_process_time_ms_ != -1 &&
now - last_process_time_ms_ < kDefaultProcessIntervalMs) {
time_until_next = (last_process_time_ms_ + kDefaultProcessIntervalMs - now);
}
return time_until_next;
}
int32_t RemoteEstimatorProxy::Process() {
// TODO(sprang): Perhaps we need a dedicated thread here instead?
if (TimeUntilNextProcess() > 0)
return 0;
last_process_time_ms_ = clock_->TimeInMilliseconds();
bool more_to_build = true;
while (more_to_build) {
rtcp::TransportFeedback feedback_packet;
if (BuildFeedbackPacket(&feedback_packet)) {
RTC_DCHECK(packet_router_ != nullptr);
packet_router_->SendFeedback(&feedback_packet);
} else {
more_to_build = false;
}
}
return 0;
}
void RemoteEstimatorProxy::OnPacketArrival(uint16_t sequence_number,
int64_t arrival_time) {
int64_t seq = unwrapper_.Unwrap(sequence_number);
if (window_start_seq_ == -1) {
window_start_seq_ = seq;
// Start new feedback packet, cull old packets.
for (auto it = packet_arrival_times_.begin();
it != packet_arrival_times_.end() && it->first < seq &&
arrival_time - it->second >= kBackWindowMs;) {
auto delete_it = it;
++it;
packet_arrival_times_.erase(delete_it);
}
} else if (seq < window_start_seq_) {
window_start_seq_ = seq;
}
RTC_DCHECK(packet_arrival_times_.end() == packet_arrival_times_.find(seq));
packet_arrival_times_[seq] = arrival_time;
}
bool RemoteEstimatorProxy::BuildFeedbackPacket(
rtcp::TransportFeedback* feedback_packet) {
rtc::CritScope cs(&lock_);
if (window_start_seq_ == -1)
return false;
// window_start_seq_ is the first sequence number to include in the current
// feedback packet. Some older may still be in the map, in case a reordering
// happens and we need to retransmit them.
auto it = packet_arrival_times_.find(window_start_seq_);
RTC_DCHECK(it != packet_arrival_times_.end());
// TODO(sprang): Measure receive times in microseconds and remove the
// conversions below.
feedback_packet->WithMediaSourceSsrc(media_ssrc_);
feedback_packet->WithBase(static_cast<uint16_t>(it->first & 0xFFFF),
it->second * 1000);
feedback_packet->WithFeedbackSequenceNumber(feedback_sequence_++);
for (; it != packet_arrival_times_.end(); ++it) {
if (!feedback_packet->WithReceivedPacket(
static_cast<uint16_t>(it->first & 0xFFFF), it->second * 1000)) {
// If we can't even add the first seq to the feedback packet, we won't be
// able to build it at all.
RTC_CHECK_NE(window_start_seq_, it->first);
// Could not add timestamp, feedback packet might be full. Return and
// try again with a fresh packet.
window_start_seq_ = it->first;
break;
}
// Note: Don't erase items from packet_arrival_times_ after sending, in case
// they need to be re-sent after a reordering. Removal will be handled
// by OnPacketArrival once packets are too old.
}
if (it == packet_arrival_times_.end())
window_start_seq_ = -1;
return true;
}
} // namespace webrtc
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