1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "media/cast/rtcp/rtcp.h"
7 #include "base/rand_util.h"
8 #include "media/cast/cast_config.h"
9 #include "media/cast/cast_defines.h"
10 #include "media/cast/cast_environment.h"
11 #include "media/cast/rtcp/rtcp_defines.h"
12 #include "media/cast/rtcp/rtcp_receiver.h"
13 #include "media/cast/rtcp/rtcp_sender.h"
14 #include "media/cast/rtcp/rtcp_utility.h"
15 #include "media/cast/transport/cast_transport_defines.h"
16 #include "net/base/big_endian.h"
21 static const int kMaxRttMs = 10000; // 10 seconds.
23 // Time limit for received RTCP messages when we stop using it for lip-sync.
24 static const int64 kMaxDiffSinceReceivedRtcpMs = 100000; // 100 seconds.
26 class LocalRtcpRttFeedback : public RtcpRttFeedback {
28 explicit LocalRtcpRttFeedback(Rtcp* rtcp) : rtcp_(rtcp) {}
30 virtual void OnReceivedDelaySinceLastReport(
31 uint32 receivers_ssrc, uint32 last_report,
32 uint32 delay_since_last_report) OVERRIDE {
33 rtcp_->OnReceivedDelaySinceLastReport(receivers_ssrc, last_report,
34 delay_since_last_report);
41 class LocalRtcpReceiverFeedback : public RtcpReceiverFeedback {
43 LocalRtcpReceiverFeedback(Rtcp* rtcp,
44 scoped_refptr<CastEnvironment> cast_environment)
45 : rtcp_(rtcp), cast_environment_(cast_environment) {}
47 virtual void OnReceivedSenderReport(
48 const transport::RtcpSenderInfo& remote_sender_info) OVERRIDE {
49 rtcp_->OnReceivedNtp(remote_sender_info.ntp_seconds,
50 remote_sender_info.ntp_fraction);
51 if (remote_sender_info.send_packet_count != 0) {
52 rtcp_->OnReceivedLipSyncInfo(remote_sender_info.rtp_timestamp,
53 remote_sender_info.ntp_seconds,
54 remote_sender_info.ntp_fraction);
58 virtual void OnReceiverReferenceTimeReport(
59 const RtcpReceiverReferenceTimeReport& remote_time_report) OVERRIDE {
60 rtcp_->OnReceivedNtp(remote_time_report.ntp_seconds,
61 remote_time_report.ntp_fraction);
64 virtual void OnReceivedSendReportRequest() OVERRIDE {
65 rtcp_->OnReceivedSendReportRequest();
68 virtual void OnReceivedReceiverLog(const RtcpReceiverLogMessage& receiver_log)
70 // Add received log messages into our log system.
71 RtcpReceiverLogMessage::const_iterator it = receiver_log.begin();
73 for (; it != receiver_log.end(); ++it) {
74 uint32 rtp_timestamp = it->rtp_timestamp_;
76 RtcpReceiverEventLogMessages::const_iterator event_it =
77 it->event_log_messages_.begin();
78 for (; event_it != it->event_log_messages_.end(); ++event_it) {
79 switch (event_it->type) {
80 case kAudioPacketReceived:
81 case kVideoPacketReceived:
82 case kDuplicateAudioPacketReceived:
83 case kDuplicateVideoPacketReceived:
84 cast_environment_->Logging()->InsertPacketEvent(
85 event_it->event_timestamp, event_it->type, rtp_timestamp,
86 kFrameIdUnknown, event_it->packet_id, 0, 0);
90 case kAudioFrameDecoded:
91 case kVideoFrameDecoded:
92 cast_environment_->Logging()->InsertFrameEvent(
93 event_it->event_timestamp, event_it->type, rtp_timestamp,
96 case kAudioPlayoutDelay:
97 case kVideoRenderDelay:
98 cast_environment_->Logging()->InsertFrameEventWithDelay(
99 event_it->event_timestamp, event_it->type, rtp_timestamp,
100 kFrameIdUnknown, event_it->delay_delta);
103 VLOG(2) << "Received log message via RTCP that we did not expect: "
104 << static_cast<int>(event_it->type);
111 virtual void OnReceivedSenderLog(
112 const transport::RtcpSenderLogMessage& sender_log) OVERRIDE {
113 transport::RtcpSenderLogMessage::const_iterator it = sender_log.begin();
115 for (; it != sender_log.end(); ++it) {
116 uint32 rtp_timestamp = it->rtp_timestamp;
117 CastLoggingEvent log_event = kUnknown;
119 // These events are provided to know the status of frames that never
120 // reached the receiver. The timing information for these events are not
121 // relevant and is not sent over the wire.
122 switch (it->frame_status) {
123 case transport::kRtcpSenderFrameStatusDroppedByFlowControl:
124 // A frame that have been dropped by the flow control would have
125 // kVideoFrameCaptured as its last event in the log.
126 log_event = kVideoFrameCaptured;
128 case transport::kRtcpSenderFrameStatusDroppedByEncoder:
129 // A frame that have been dropped by the encoder would have
130 // kVideoFrameSentToEncoder as its last event in the log.
131 log_event = kVideoFrameSentToEncoder;
133 case transport::kRtcpSenderFrameStatusSentToNetwork:
134 // A frame that have be encoded is always sent to the network. We
135 // do not add a new log entry for this.
136 log_event = kVideoFrameEncoded;
141 // TODO(pwestin): how do we handle the truncated rtp_timestamp?
142 // Add received log messages into our log system.
143 // TODO(pwestin): how do we handle the time? we don't care about it but
144 // we need to send in one.
145 base::TimeTicks now = cast_environment_->Clock()->NowTicks();
146 cast_environment_->Logging()->InsertFrameEvent(
147 now, log_event, rtp_timestamp, kFrameIdUnknown);
153 scoped_refptr<CastEnvironment> cast_environment_;
156 Rtcp::Rtcp(scoped_refptr<CastEnvironment> cast_environment,
157 RtcpSenderFeedback* sender_feedback,
158 transport::CastTransportSender* const transport_sender,
159 transport::PacedPacketSender* paced_packet_sender,
160 RtpSenderStatistics* rtp_sender_statistics,
161 RtpReceiverStatistics* rtp_receiver_statistics, RtcpMode rtcp_mode,
162 const base::TimeDelta& rtcp_interval, uint32 local_ssrc,
163 uint32 remote_ssrc, const std::string& c_name)
164 : cast_environment_(cast_environment),
165 transport_sender_(transport_sender),
166 rtcp_interval_(rtcp_interval),
167 rtcp_mode_(rtcp_mode),
168 local_ssrc_(local_ssrc),
169 remote_ssrc_(remote_ssrc),
171 rtp_sender_statistics_(rtp_sender_statistics),
172 rtp_receiver_statistics_(rtp_receiver_statistics),
173 receiver_feedback_(new LocalRtcpReceiverFeedback(this, cast_environment)),
174 rtt_feedback_(new LocalRtcpRttFeedback(this)),
175 rtcp_sender_(new RtcpSender(cast_environment, paced_packet_sender,
176 local_ssrc, c_name)),
177 last_report_received_(0),
178 last_received_rtp_timestamp_(0),
179 last_received_ntp_seconds_(0),
180 last_received_ntp_fraction_(0),
181 min_rtt_(base::TimeDelta::FromMilliseconds(kMaxRttMs)),
182 number_of_rtt_in_avg_(0) {
183 rtcp_receiver_.reset(new RtcpReceiver(cast_environment, sender_feedback,
184 receiver_feedback_.get(),
185 rtt_feedback_.get(), local_ssrc));
186 rtcp_receiver_->SetRemoteSSRC(remote_ssrc);
192 bool Rtcp::IsRtcpPacket(const uint8* packet, size_t length) {
193 DCHECK_GE(length, kMinLengthOfRtcp) << "Invalid RTCP packet";
194 if (length < kMinLengthOfRtcp) return false;
196 uint8 packet_type = packet[1];
197 if (packet_type >= transport::kPacketTypeLow &&
198 packet_type <= transport::kPacketTypeHigh) {
205 uint32 Rtcp::GetSsrcOfSender(const uint8* rtcp_buffer, size_t length) {
206 DCHECK_GE(length, kMinLengthOfRtcp) << "Invalid RTCP packet";
207 uint32 ssrc_of_sender;
208 net::BigEndianReader big_endian_reader(rtcp_buffer, length);
209 big_endian_reader.Skip(4); // Skip header
210 big_endian_reader.ReadU32(&ssrc_of_sender);
211 return ssrc_of_sender;
214 base::TimeTicks Rtcp::TimeToSendNextRtcpReport() {
215 if (next_time_to_send_rtcp_.is_null()) {
216 UpdateNextTimeToSendRtcp();
218 return next_time_to_send_rtcp_;
221 void Rtcp::IncomingRtcpPacket(const uint8* rtcp_buffer, size_t length) {
222 RtcpParser rtcp_parser(rtcp_buffer, length);
223 if (!rtcp_parser.IsValid()) {
224 // Silently ignore packet.
225 DLOG(ERROR) << "Received invalid RTCP packet";
228 rtcp_receiver_->IncomingRtcpPacket(&rtcp_parser);
231 void Rtcp::SendRtcpFromRtpReceiver(
232 const RtcpCastMessage* cast_message,
233 ReceiverRtcpEventSubscriber* event_subscriber) {
234 DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
235 uint32 packet_type_flags = 0;
237 base::TimeTicks now = cast_environment_->Clock()->NowTicks();
238 transport::RtcpReportBlock report_block;
239 RtcpReceiverReferenceTimeReport rrtr;
242 packet_type_flags |= RtcpSender::kRtcpCast;
244 if (event_subscriber) {
245 packet_type_flags |= RtcpSender::kRtcpReceiverLog;
247 if (rtcp_mode_ == kRtcpCompound || now >= next_time_to_send_rtcp_) {
248 packet_type_flags |= RtcpSender::kRtcpRr;
250 report_block.remote_ssrc = 0; // Not needed to set send side.
251 report_block.media_ssrc = remote_ssrc_; // SSRC of the RTP packet sender.
252 if (rtp_receiver_statistics_) {
253 rtp_receiver_statistics_->GetStatistics(
254 &report_block.fraction_lost, &report_block.cumulative_lost,
255 &report_block.extended_high_sequence_number, &report_block.jitter);
256 cast_environment_->Logging()->InsertGenericEvent(now, kJitterMs,
257 report_block.jitter);
258 cast_environment_->Logging()->InsertGenericEvent(
259 now, kPacketLoss, report_block.fraction_lost);
262 report_block.last_sr = last_report_received_;
263 if (!time_last_report_received_.is_null()) {
264 uint32 delay_seconds = 0;
265 uint32 delay_fraction = 0;
266 base::TimeDelta delta = now - time_last_report_received_;
267 ConvertTimeToFractions(delta.InMicroseconds(), &delay_seconds,
269 report_block.delay_since_last_sr =
270 ConvertToNtpDiff(delay_seconds, delay_fraction);
272 report_block.delay_since_last_sr = 0;
275 packet_type_flags |= RtcpSender::kRtcpRrtr;
276 ConvertTimeTicksToNtp(now, &rrtr.ntp_seconds, &rrtr.ntp_fraction);
277 SaveLastSentNtpTime(now, rrtr.ntp_seconds, rrtr.ntp_fraction);
278 UpdateNextTimeToSendRtcp();
280 rtcp_sender_->SendRtcpFromRtpReceiver(
281 packet_type_flags, &report_block, &rrtr, cast_message, event_subscriber);
284 void Rtcp::SendRtcpFromRtpSender(
285 const transport::RtcpSenderLogMessage& sender_log_message) {
286 DCHECK(transport_sender_);
287 uint32 packet_type_flags = RtcpSender::kRtcpSr;
288 base::TimeTicks now = cast_environment_->Clock()->NowTicks();
290 if (sender_log_message.size()) {
291 packet_type_flags |= RtcpSender::kRtcpSenderLog;
294 transport::RtcpSenderInfo sender_info;
295 if (rtp_sender_statistics_) {
296 rtp_sender_statistics_->GetStatistics(now, &sender_info);
298 memset(&sender_info, 0, sizeof(sender_info));
300 SaveLastSentNtpTime(now, sender_info.ntp_seconds, sender_info.ntp_fraction);
302 transport::RtcpDlrrReportBlock dlrr;
303 if (!time_last_report_received_.is_null()) {
304 packet_type_flags |= RtcpSender::kRtcpDlrr;
305 dlrr.last_rr = last_report_received_;
306 uint32 delay_seconds = 0;
307 uint32 delay_fraction = 0;
308 base::TimeDelta delta = now - time_last_report_received_;
309 ConvertTimeToFractions(delta.InMicroseconds(), &delay_seconds,
312 dlrr.delay_since_last_rr = ConvertToNtpDiff(delay_seconds, delay_fraction);
315 cast_environment_->PostTask(
316 CastEnvironment::TRANSPORT, FROM_HERE,
317 base::Bind(&Rtcp::SendRtcpFromRtpSenderOnTransportThread,
318 base::Unretained(this), packet_type_flags, sender_info, dlrr,
319 sender_log_message, local_ssrc_, c_name_));
320 UpdateNextTimeToSendRtcp();
323 void Rtcp::SendRtcpFromRtpSenderOnTransportThread(
324 uint32 packet_type_flags, const transport::RtcpSenderInfo& sender_info,
325 const transport::RtcpDlrrReportBlock& dlrr,
326 const transport::RtcpSenderLogMessage& sender_log, uint32 sending_ssrc,
327 std::string c_name) {
328 DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::TRANSPORT));
329 transport_sender_->SendRtcpFromRtpSender(packet_type_flags, sender_info, dlrr,
330 sender_log, sending_ssrc, c_name);
333 void Rtcp::OnReceivedNtp(uint32 ntp_seconds, uint32 ntp_fraction) {
334 last_report_received_ = (ntp_seconds << 16) + (ntp_fraction >> 16);
336 base::TimeTicks now = cast_environment_->Clock()->NowTicks();
337 time_last_report_received_ = now;
340 void Rtcp::OnReceivedLipSyncInfo(uint32 rtp_timestamp, uint32 ntp_seconds,
341 uint32 ntp_fraction) {
342 last_received_rtp_timestamp_ = rtp_timestamp;
343 last_received_ntp_seconds_ = ntp_seconds;
344 last_received_ntp_fraction_ = ntp_fraction;
347 void Rtcp::OnReceivedSendReportRequest() {
348 base::TimeTicks now = cast_environment_->Clock()->NowTicks();
350 // Trigger a new RTCP report at next timer.
351 next_time_to_send_rtcp_ = now;
354 bool Rtcp::RtpTimestampInSenderTime(int frequency, uint32 rtp_timestamp,
355 base::TimeTicks* rtp_timestamp_in_ticks)
357 if (last_received_ntp_seconds_ == 0)
360 int wrap = CheckForWrapAround(rtp_timestamp, last_received_rtp_timestamp_);
361 int64 rtp_timestamp_int64 = rtp_timestamp;
362 int64 last_received_rtp_timestamp_int64 = last_received_rtp_timestamp_;
365 rtp_timestamp_int64 += (1LL << 32);
366 } else if (wrap == -1) {
367 last_received_rtp_timestamp_int64 += (1LL << 32);
369 // Time since the last RTCP message.
370 // Note that this can be negative since we can compare a rtp timestamp from
371 // a frame older than the last received RTCP message.
372 int64 rtp_timestamp_diff =
373 rtp_timestamp_int64 - last_received_rtp_timestamp_int64;
375 int frequency_khz = frequency / 1000;
376 int64 rtp_time_diff_ms = rtp_timestamp_diff / frequency_khz;
379 if (abs(rtp_time_diff_ms) > kMaxDiffSinceReceivedRtcpMs)
382 *rtp_timestamp_in_ticks = ConvertNtpToTimeTicks(last_received_ntp_seconds_,
383 last_received_ntp_fraction_) +
384 base::TimeDelta::FromMilliseconds(rtp_time_diff_ms);
388 void Rtcp::OnReceivedDelaySinceLastReport(uint32 receivers_ssrc,
390 uint32 delay_since_last_report) {
391 RtcpSendTimeMap::iterator it = last_reports_sent_map_.find(last_report);
392 if (it == last_reports_sent_map_.end()) {
393 return; // Feedback on another report.
396 base::TimeDelta sender_delay =
397 cast_environment_->Clock()->NowTicks() - it->second;
398 UpdateRtt(sender_delay, ConvertFromNtpDiff(delay_since_last_report));
401 void Rtcp::SaveLastSentNtpTime(const base::TimeTicks& now,
402 uint32 last_ntp_seconds,
403 uint32 last_ntp_fraction) {
404 // Make sure |now| is always greater than the last element in
405 // |last_reports_sent_queue_|.
406 if (!last_reports_sent_queue_.empty())
407 DCHECK(now >= last_reports_sent_queue_.back().second);
409 uint32 last_report = ConvertToNtpDiff(last_ntp_seconds, last_ntp_fraction);
410 last_reports_sent_map_[last_report] = now;
411 last_reports_sent_queue_.push(std::make_pair(last_report, now));
413 base::TimeTicks timeout = now - base::TimeDelta::FromMilliseconds(kMaxRttMs);
415 // Cleanup old statistics older than |timeout|.
416 while (!last_reports_sent_queue_.empty()) {
417 RtcpSendTimePair oldest_report = last_reports_sent_queue_.front();
418 if (oldest_report.second < timeout) {
419 last_reports_sent_map_.erase(oldest_report.first);
420 last_reports_sent_queue_.pop();
427 void Rtcp::UpdateRtt(const base::TimeDelta& sender_delay,
428 const base::TimeDelta& receiver_delay) {
429 base::TimeDelta rtt = sender_delay - receiver_delay;
430 rtt = std::max(rtt, base::TimeDelta::FromMilliseconds(1));
432 min_rtt_ = std::min(min_rtt_, rtt);
433 max_rtt_ = std::max(max_rtt_, rtt);
435 if (number_of_rtt_in_avg_ != 0) {
436 float ac = static_cast<float>(number_of_rtt_in_avg_);
437 avg_rtt_ms_ = ((ac / (ac + 1.0)) * avg_rtt_ms_) +
438 ((1.0 / (ac + 1.0)) * rtt.InMilliseconds());
440 avg_rtt_ms_ = rtt.InMilliseconds();
442 number_of_rtt_in_avg_++;
445 bool Rtcp::Rtt(base::TimeDelta* rtt, base::TimeDelta* avg_rtt,
446 base::TimeDelta* min_rtt, base::TimeDelta* max_rtt) const {
447 DCHECK(rtt) << "Invalid argument";
448 DCHECK(avg_rtt) << "Invalid argument";
449 DCHECK(min_rtt) << "Invalid argument";
450 DCHECK(max_rtt) << "Invalid argument";
452 if (number_of_rtt_in_avg_ == 0) return false;
454 base::TimeTicks now = cast_environment_->Clock()->NowTicks();
455 cast_environment_->Logging()->InsertGenericEvent(now, kRttMs,
456 rtt->InMilliseconds());
459 *avg_rtt = base::TimeDelta::FromMilliseconds(avg_rtt_ms_);
465 int Rtcp::CheckForWrapAround(uint32 new_timestamp, uint32 old_timestamp) const {
466 if (new_timestamp < old_timestamp) {
467 // This difference should be less than -2^31 if we have had a wrap around
468 // (e.g. |new_timestamp| = 1, |rtcp_rtp_timestamp| = 2^32 - 1). Since it is
469 // cast to a int32_t, it should be positive.
470 if (static_cast<int32>(new_timestamp - old_timestamp) > 0) {
471 return 1; // Forward wrap around.
473 } else if (static_cast<int32>(old_timestamp - new_timestamp) > 0) {
474 // This difference should be less than -2^31 if we have had a backward wrap
475 // around. Since it is cast to a int32, it should be positive.
481 void Rtcp::UpdateNextTimeToSendRtcp() {
482 int random = base::RandInt(0, 999);
483 base::TimeDelta time_to_next =
484 (rtcp_interval_ / 2) + (rtcp_interval_ * random / 1000);
486 base::TimeTicks now = cast_environment_->Clock()->NowTicks();
487 next_time_to_send_rtcp_ = now + time_to_next;