xref: /aosp_15_r20/external/webrtc/video/video_analyzer.cc (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1 /*
2  *  Copyright 2018 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 #include "video/video_analyzer.h"
11 
12 #include <inttypes.h>
13 
14 #include <algorithm>
15 #include <utility>
16 
17 #include "absl/algorithm/container.h"
18 #include "absl/flags/flag.h"
19 #include "absl/flags/parse.h"
20 #include "absl/strings/string_view.h"
21 #include "api/test/metrics/global_metrics_logger_and_exporter.h"
22 #include "api/test/metrics/metric.h"
23 #include "common_video/libyuv/include/webrtc_libyuv.h"
24 #include "modules/rtp_rtcp/source/create_video_rtp_depacketizer.h"
25 #include "modules/rtp_rtcp/source/rtp_packet.h"
26 #include "modules/rtp_rtcp/source/rtp_util.h"
27 #include "rtc_base/cpu_time.h"
28 #include "rtc_base/memory_usage.h"
29 #include "rtc_base/task_queue_for_test.h"
30 #include "rtc_base/task_utils/repeating_task.h"
31 #include "rtc_base/time_utils.h"
32 #include "system_wrappers/include/cpu_info.h"
33 #include "test/call_test.h"
34 #include "test/testsupport/file_utils.h"
35 #include "test/testsupport/frame_writer.h"
36 #include "test/testsupport/test_artifacts.h"
37 
38 ABSL_FLAG(bool,
39           save_worst_frame,
40           false,
41           "Enable saving a frame with the lowest PSNR to a jpeg file in the "
42           "test_artifacts_dir");
43 
44 namespace webrtc {
45 namespace {
46 
47 using ::webrtc::test::GetGlobalMetricsLogger;
48 using ::webrtc::test::ImprovementDirection;
49 using ::webrtc::test::Metric;
50 using ::webrtc::test::Unit;
51 
52 constexpr TimeDelta kSendStatsPollingInterval = TimeDelta::Seconds(1);
53 constexpr size_t kMaxComparisons = 10;
54 // How often is keep alive message printed.
55 constexpr TimeDelta kKeepAliveInterval = TimeDelta::Seconds(30);
56 // Interval between checking that the test is over.
57 constexpr TimeDelta kProbingInterval = TimeDelta::Millis(500);
58 constexpr int kKeepAliveIntervalIterations =
59     kKeepAliveInterval.ms() / kProbingInterval.ms();
60 
IsFlexfec(int payload_type)61 bool IsFlexfec(int payload_type) {
62   return payload_type == test::CallTest::kFlexfecPayloadType;
63 }
64 
65 }  // namespace
66 
VideoAnalyzer(test::LayerFilteringTransport * transport,const std::string & test_label,double avg_psnr_threshold,double avg_ssim_threshold,int duration_frames,TimeDelta test_duration,FILE * graph_data_output_file,const std::string & graph_title,uint32_t ssrc_to_analyze,uint32_t rtx_ssrc_to_analyze,size_t selected_stream,int selected_sl,int selected_tl,bool is_quick_test_enabled,Clock * clock,std::string rtp_dump_name,TaskQueueBase * task_queue)67 VideoAnalyzer::VideoAnalyzer(test::LayerFilteringTransport* transport,
68                              const std::string& test_label,
69                              double avg_psnr_threshold,
70                              double avg_ssim_threshold,
71                              int duration_frames,
72                              TimeDelta test_duration,
73                              FILE* graph_data_output_file,
74                              const std::string& graph_title,
75                              uint32_t ssrc_to_analyze,
76                              uint32_t rtx_ssrc_to_analyze,
77                              size_t selected_stream,
78                              int selected_sl,
79                              int selected_tl,
80                              bool is_quick_test_enabled,
81                              Clock* clock,
82                              std::string rtp_dump_name,
83                              TaskQueueBase* task_queue)
84     : transport_(transport),
85       receiver_(nullptr),
86       call_(nullptr),
87       send_stream_(nullptr),
88       receive_stream_(nullptr),
89       audio_receive_stream_(nullptr),
90       captured_frame_forwarder_(this, clock, duration_frames, test_duration),
91       test_label_(test_label),
92       graph_data_output_file_(graph_data_output_file),
93       graph_title_(graph_title),
94       ssrc_to_analyze_(ssrc_to_analyze),
95       rtx_ssrc_to_analyze_(rtx_ssrc_to_analyze),
96       selected_stream_(selected_stream),
97       selected_sl_(selected_sl),
98       selected_tl_(selected_tl),
99       mean_decode_time_ms_(0.0),
100       freeze_count_(0),
101       total_freezes_duration_ms_(0),
102       total_frames_duration_ms_(0),
103       sum_squared_frame_durations_(0),
104       decode_frame_rate_(0),
105       render_frame_rate_(0),
106       last_fec_bytes_(0),
107       frames_to_process_(duration_frames),
108       test_end_(clock->CurrentTime() + test_duration),
109       frames_recorded_(0),
110       frames_processed_(0),
111       captured_frames_(0),
112       dropped_frames_(0),
113       dropped_frames_before_first_encode_(0),
114       dropped_frames_before_rendering_(0),
115       last_render_time_(0),
116       last_render_delta_ms_(0),
117       last_unfreeze_time_ms_(0),
118       rtp_timestamp_delta_(0),
119       cpu_time_(0),
120       wallclock_time_(0),
121       avg_psnr_threshold_(avg_psnr_threshold),
122       avg_ssim_threshold_(avg_ssim_threshold),
123       is_quick_test_enabled_(is_quick_test_enabled),
124       quit_(false),
125       done_(true, false),
126       vp8_depacketizer_(CreateVideoRtpDepacketizer(kVideoCodecVP8)),
127       vp9_depacketizer_(CreateVideoRtpDepacketizer(kVideoCodecVP9)),
128       clock_(clock),
129       start_ms_(clock->TimeInMilliseconds()),
130       task_queue_(task_queue) {
131   // Create thread pool for CPU-expensive PSNR/SSIM calculations.
132 
133   // Try to use about as many threads as cores, but leave kMinCoresLeft alone,
134   // so that we don't accidentally starve "real" worker threads (codec etc).
135   // Also, don't allocate more than kMaxComparisonThreads, even if there are
136   // spare cores.
137 
138   uint32_t num_cores = CpuInfo::DetectNumberOfCores();
139   RTC_DCHECK_GE(num_cores, 1);
140   static const uint32_t kMinCoresLeft = 4;
141   static const uint32_t kMaxComparisonThreads = 8;
142 
143   if (num_cores <= kMinCoresLeft) {
144     num_cores = 1;
145   } else {
146     num_cores -= kMinCoresLeft;
147     num_cores = std::min(num_cores, kMaxComparisonThreads);
148   }
149 
150   for (uint32_t i = 0; i < num_cores; ++i) {
151     comparison_thread_pool_.push_back(rtc::PlatformThread::SpawnJoinable(
152         [this] {
153           while (CompareFrames()) {
154           }
155         },
156         "Analyzer"));
157   }
158 
159   if (!rtp_dump_name.empty()) {
160     fprintf(stdout, "Writing rtp dump to %s\n", rtp_dump_name.c_str());
161     rtp_file_writer_.reset(test::RtpFileWriter::Create(
162         test::RtpFileWriter::kRtpDump, rtp_dump_name));
163   }
164 }
165 
~VideoAnalyzer()166 VideoAnalyzer::~VideoAnalyzer() {
167   {
168     MutexLock lock(&comparison_lock_);
169     quit_ = true;
170   }
171   // Joins all threads.
172   comparison_thread_pool_.clear();
173 }
174 
SetReceiver(PacketReceiver * receiver)175 void VideoAnalyzer::SetReceiver(PacketReceiver* receiver) {
176   receiver_ = receiver;
177 }
178 
SetSource(rtc::VideoSourceInterface<VideoFrame> * video_source,bool respect_sink_wants)179 void VideoAnalyzer::SetSource(
180     rtc::VideoSourceInterface<VideoFrame>* video_source,
181     bool respect_sink_wants) {
182   if (respect_sink_wants)
183     captured_frame_forwarder_.SetSource(video_source);
184   rtc::VideoSinkWants wants;
185   video_source->AddOrUpdateSink(InputInterface(), wants);
186 }
187 
SetCall(Call * call)188 void VideoAnalyzer::SetCall(Call* call) {
189   MutexLock lock(&lock_);
190   RTC_DCHECK(!call_);
191   call_ = call;
192 }
193 
SetSendStream(VideoSendStream * stream)194 void VideoAnalyzer::SetSendStream(VideoSendStream* stream) {
195   MutexLock lock(&lock_);
196   RTC_DCHECK(!send_stream_);
197   send_stream_ = stream;
198 }
199 
SetReceiveStream(VideoReceiveStreamInterface * stream)200 void VideoAnalyzer::SetReceiveStream(VideoReceiveStreamInterface* stream) {
201   MutexLock lock(&lock_);
202   RTC_DCHECK(!receive_stream_);
203   receive_stream_ = stream;
204 }
205 
SetAudioReceiveStream(AudioReceiveStreamInterface * recv_stream)206 void VideoAnalyzer::SetAudioReceiveStream(
207     AudioReceiveStreamInterface* recv_stream) {
208   MutexLock lock(&lock_);
209   RTC_CHECK(!audio_receive_stream_);
210   audio_receive_stream_ = recv_stream;
211 }
212 
InputInterface()213 rtc::VideoSinkInterface<VideoFrame>* VideoAnalyzer::InputInterface() {
214   return &captured_frame_forwarder_;
215 }
216 
OutputInterface()217 rtc::VideoSourceInterface<VideoFrame>* VideoAnalyzer::OutputInterface() {
218   return &captured_frame_forwarder_;
219 }
220 
DeliverPacket(MediaType media_type,rtc::CopyOnWriteBuffer packet,int64_t packet_time_us)221 PacketReceiver::DeliveryStatus VideoAnalyzer::DeliverPacket(
222     MediaType media_type,
223     rtc::CopyOnWriteBuffer packet,
224     int64_t packet_time_us) {
225   // Ignore timestamps of RTCP packets. They're not synchronized with
226   // RTP packet timestamps and so they would confuse wrap_handler_.
227   if (IsRtcpPacket(packet)) {
228     return receiver_->DeliverPacket(media_type, std::move(packet),
229                                     packet_time_us);
230   }
231 
232   if (rtp_file_writer_) {
233     test::RtpPacket p;
234     memcpy(p.data, packet.cdata(), packet.size());
235     p.length = packet.size();
236     p.original_length = packet.size();
237     p.time_ms = clock_->TimeInMilliseconds() - start_ms_;
238     rtp_file_writer_->WritePacket(&p);
239   }
240 
241   RtpPacket rtp_packet;
242   rtp_packet.Parse(packet);
243   if (!IsFlexfec(rtp_packet.PayloadType()) &&
244       (rtp_packet.Ssrc() == ssrc_to_analyze_ ||
245        rtp_packet.Ssrc() == rtx_ssrc_to_analyze_)) {
246     // Ignore FlexFEC timestamps, to avoid collisions with media timestamps.
247     // (FlexFEC and media are sent on different SSRCs, which have different
248     // timestamps spaces.)
249     // Also ignore packets from wrong SSRC, but include retransmits.
250     MutexLock lock(&lock_);
251     int64_t timestamp =
252         wrap_handler_.Unwrap(rtp_packet.Timestamp() - rtp_timestamp_delta_);
253     recv_times_[timestamp] = clock_->CurrentNtpInMilliseconds();
254   }
255 
256   return receiver_->DeliverPacket(media_type, std::move(packet),
257                                   packet_time_us);
258 }
259 
PreEncodeOnFrame(const VideoFrame & video_frame)260 void VideoAnalyzer::PreEncodeOnFrame(const VideoFrame& video_frame) {
261   MutexLock lock(&lock_);
262   if (!first_encoded_timestamp_) {
263     while (frames_.front().timestamp() != video_frame.timestamp()) {
264       ++dropped_frames_before_first_encode_;
265       frames_.pop_front();
266       RTC_CHECK(!frames_.empty());
267     }
268     first_encoded_timestamp_ = video_frame.timestamp();
269   }
270 }
271 
PostEncodeOnFrame(size_t stream_id,uint32_t timestamp)272 void VideoAnalyzer::PostEncodeOnFrame(size_t stream_id, uint32_t timestamp) {
273   MutexLock lock(&lock_);
274   if (!first_sent_timestamp_ && stream_id == selected_stream_) {
275     first_sent_timestamp_ = timestamp;
276   }
277 }
278 
SendRtp(const uint8_t * packet,size_t length,const PacketOptions & options)279 bool VideoAnalyzer::SendRtp(const uint8_t* packet,
280                             size_t length,
281                             const PacketOptions& options) {
282   RtpPacket rtp_packet;
283   rtp_packet.Parse(packet, length);
284 
285   int64_t current_time = clock_->CurrentNtpInMilliseconds();
286 
287   bool result = transport_->SendRtp(packet, length, options);
288   {
289     MutexLock lock(&lock_);
290     if (rtp_timestamp_delta_ == 0 && rtp_packet.Ssrc() == ssrc_to_analyze_) {
291       RTC_CHECK(static_cast<bool>(first_sent_timestamp_));
292       rtp_timestamp_delta_ = rtp_packet.Timestamp() - *first_sent_timestamp_;
293     }
294 
295     if (!IsFlexfec(rtp_packet.PayloadType()) &&
296         rtp_packet.Ssrc() == ssrc_to_analyze_) {
297       // Ignore FlexFEC timestamps, to avoid collisions with media timestamps.
298       // (FlexFEC and media are sent on different SSRCs, which have different
299       // timestamps spaces.)
300       // Also ignore packets from wrong SSRC and retransmits.
301       int64_t timestamp =
302           wrap_handler_.Unwrap(rtp_packet.Timestamp() - rtp_timestamp_delta_);
303       send_times_[timestamp] = current_time;
304 
305       if (IsInSelectedSpatialAndTemporalLayer(rtp_packet)) {
306         encoded_frame_sizes_[timestamp] += rtp_packet.payload_size();
307       }
308     }
309   }
310   return result;
311 }
312 
SendRtcp(const uint8_t * packet,size_t length)313 bool VideoAnalyzer::SendRtcp(const uint8_t* packet, size_t length) {
314   return transport_->SendRtcp(packet, length);
315 }
316 
OnFrame(const VideoFrame & video_frame)317 void VideoAnalyzer::OnFrame(const VideoFrame& video_frame) {
318   int64_t render_time_ms = clock_->CurrentNtpInMilliseconds();
319 
320   MutexLock lock(&lock_);
321 
322   StartExcludingCpuThreadTime();
323 
324   int64_t send_timestamp =
325       wrap_handler_.Unwrap(video_frame.timestamp() - rtp_timestamp_delta_);
326 
327   while (wrap_handler_.Unwrap(frames_.front().timestamp()) < send_timestamp) {
328     if (!last_rendered_frame_) {
329       // No previous frame rendered, this one was dropped after sending but
330       // before rendering.
331       ++dropped_frames_before_rendering_;
332     } else {
333       AddFrameComparison(frames_.front(), *last_rendered_frame_, true,
334                          render_time_ms);
335     }
336     frames_.pop_front();
337     RTC_DCHECK(!frames_.empty());
338   }
339 
340   VideoFrame reference_frame = frames_.front();
341   frames_.pop_front();
342   int64_t reference_timestamp =
343       wrap_handler_.Unwrap(reference_frame.timestamp());
344   if (send_timestamp == reference_timestamp - 1) {
345     // TODO(ivica): Make this work for > 2 streams.
346     // Look at RTPSender::BuildRTPHeader.
347     ++send_timestamp;
348   }
349   ASSERT_EQ(reference_timestamp, send_timestamp);
350 
351   AddFrameComparison(reference_frame, video_frame, false, render_time_ms);
352 
353   last_rendered_frame_ = video_frame;
354 
355   StopExcludingCpuThreadTime();
356 }
357 
Wait()358 void VideoAnalyzer::Wait() {
359   // Frame comparisons can be very expensive. Wait for test to be done, but
360   // at time-out check if frames_processed is going up. If so, give it more
361   // time, otherwise fail. Hopefully this will reduce test flakiness.
362 
363   RepeatingTaskHandle stats_polling_task = RepeatingTaskHandle::DelayedStart(
364       task_queue_, kSendStatsPollingInterval, [this] {
365         PollStats();
366         return kSendStatsPollingInterval;
367       });
368 
369   int last_frames_processed = -1;
370   int last_frames_captured = -1;
371   int iteration = 0;
372 
373   while (!done_.Wait(kProbingInterval)) {
374     int frames_processed;
375     int frames_captured;
376     {
377       MutexLock lock(&comparison_lock_);
378       frames_processed = frames_processed_;
379       frames_captured = captured_frames_;
380     }
381 
382     // Print some output so test infrastructure won't think we've crashed.
383     const char* kKeepAliveMessages[3] = {
384         "Uh, I'm-I'm not quite dead, sir.",
385         "Uh, I-I think uh, I could pull through, sir.",
386         "Actually, I think I'm all right to come with you--"};
387     if (++iteration % kKeepAliveIntervalIterations == 0) {
388       printf("- %s\n", kKeepAliveMessages[iteration % 3]);
389     }
390 
391     if (last_frames_processed == -1) {
392       last_frames_processed = frames_processed;
393       last_frames_captured = frames_captured;
394       continue;
395     }
396     if (frames_processed == last_frames_processed &&
397         last_frames_captured == frames_captured &&
398         clock_->CurrentTime() > test_end_) {
399       done_.Set();
400       break;
401     }
402     last_frames_processed = frames_processed;
403     last_frames_captured = frames_captured;
404   }
405 
406   if (iteration > 0)
407     printf("- Farewell, sweet Concorde!\n");
408 
409   SendTask(task_queue_, [&] { stats_polling_task.Stop(); });
410 
411   PrintResults();
412   if (graph_data_output_file_)
413     PrintSamplesToFile();
414 }
415 
StartMeasuringCpuProcessTime()416 void VideoAnalyzer::StartMeasuringCpuProcessTime() {
417   MutexLock lock(&cpu_measurement_lock_);
418   cpu_time_ -= rtc::GetProcessCpuTimeNanos();
419   wallclock_time_ -= rtc::SystemTimeNanos();
420 }
421 
StopMeasuringCpuProcessTime()422 void VideoAnalyzer::StopMeasuringCpuProcessTime() {
423   MutexLock lock(&cpu_measurement_lock_);
424   cpu_time_ += rtc::GetProcessCpuTimeNanos();
425   wallclock_time_ += rtc::SystemTimeNanos();
426 }
427 
StartExcludingCpuThreadTime()428 void VideoAnalyzer::StartExcludingCpuThreadTime() {
429   MutexLock lock(&cpu_measurement_lock_);
430   cpu_time_ += rtc::GetThreadCpuTimeNanos();
431 }
432 
StopExcludingCpuThreadTime()433 void VideoAnalyzer::StopExcludingCpuThreadTime() {
434   MutexLock lock(&cpu_measurement_lock_);
435   cpu_time_ -= rtc::GetThreadCpuTimeNanos();
436 }
437 
GetCpuUsagePercent()438 double VideoAnalyzer::GetCpuUsagePercent() {
439   MutexLock lock(&cpu_measurement_lock_);
440   return static_cast<double>(cpu_time_) / wallclock_time_ * 100.0;
441 }
442 
IsInSelectedSpatialAndTemporalLayer(const RtpPacket & rtp_packet)443 bool VideoAnalyzer::IsInSelectedSpatialAndTemporalLayer(
444     const RtpPacket& rtp_packet) {
445   if (rtp_packet.PayloadType() == test::CallTest::kPayloadTypeVP8) {
446     auto parsed_payload = vp8_depacketizer_->Parse(rtp_packet.PayloadBuffer());
447     RTC_DCHECK(parsed_payload);
448     const auto& vp8_header = absl::get<RTPVideoHeaderVP8>(
449         parsed_payload->video_header.video_type_header);
450     int temporal_idx = vp8_header.temporalIdx;
451     return selected_tl_ < 0 || temporal_idx == kNoTemporalIdx ||
452            temporal_idx <= selected_tl_;
453   }
454 
455   if (rtp_packet.PayloadType() == test::CallTest::kPayloadTypeVP9) {
456     auto parsed_payload = vp9_depacketizer_->Parse(rtp_packet.PayloadBuffer());
457     RTC_DCHECK(parsed_payload);
458     const auto& vp9_header = absl::get<RTPVideoHeaderVP9>(
459         parsed_payload->video_header.video_type_header);
460     int temporal_idx = vp9_header.temporal_idx;
461     int spatial_idx = vp9_header.spatial_idx;
462     return (selected_tl_ < 0 || temporal_idx == kNoTemporalIdx ||
463             temporal_idx <= selected_tl_) &&
464            (selected_sl_ < 0 || spatial_idx == kNoSpatialIdx ||
465             spatial_idx <= selected_sl_);
466   }
467 
468   return true;
469 }
470 
PollStats()471 void VideoAnalyzer::PollStats() {
472   // Do not grab `comparison_lock_`, before `GetStats()` completes.
473   // Otherwise a deadlock may occur:
474   // 1) `comparison_lock_` is acquired after `lock_`
475   // 2) `lock_` is acquired after internal pacer lock in SendRtp()
476   // 3) internal pacer lock is acquired by GetStats().
477   Call::Stats call_stats = call_->GetStats();
478 
479   MutexLock lock(&comparison_lock_);
480 
481   send_bandwidth_bps_.AddSample(call_stats.send_bandwidth_bps);
482 
483   VideoSendStream::Stats send_stats = send_stream_->GetStats();
484   // It's not certain that we yet have estimates for any of these stats.
485   // Check that they are positive before mixing them in.
486   if (send_stats.encode_frame_rate > 0)
487     encode_frame_rate_.AddSample(send_stats.encode_frame_rate);
488   if (send_stats.avg_encode_time_ms > 0)
489     encode_time_ms_.AddSample(send_stats.avg_encode_time_ms);
490   if (send_stats.encode_usage_percent > 0)
491     encode_usage_percent_.AddSample(send_stats.encode_usage_percent);
492   if (send_stats.media_bitrate_bps > 0)
493     media_bitrate_bps_.AddSample(send_stats.media_bitrate_bps);
494   size_t fec_bytes = 0;
495   for (const auto& kv : send_stats.substreams) {
496     fec_bytes += kv.second.rtp_stats.fec.payload_bytes +
497                  kv.second.rtp_stats.fec.padding_bytes;
498   }
499   fec_bitrate_bps_.AddSample((fec_bytes - last_fec_bytes_) * 8);
500   last_fec_bytes_ = fec_bytes;
501 
502   if (receive_stream_ != nullptr) {
503     VideoReceiveStreamInterface::Stats receive_stats =
504         receive_stream_->GetStats();
505     // `total_decode_time_ms` gives a good estimate of the mean decode time,
506     // `decode_ms` is used to keep track of the standard deviation.
507     if (receive_stats.frames_decoded > 0)
508       mean_decode_time_ms_ = receive_stats.total_decode_time.ms<double>() /
509                              receive_stats.frames_decoded;
510     if (receive_stats.decode_ms > 0)
511       decode_time_ms_.AddSample(receive_stats.decode_ms);
512     if (receive_stats.max_decode_ms > 0)
513       decode_time_max_ms_.AddSample(receive_stats.max_decode_ms);
514     if (receive_stats.width > 0 && receive_stats.height > 0) {
515       pixels_.AddSample(receive_stats.width * receive_stats.height);
516     }
517 
518     // `frames_decoded` and `frames_rendered` are used because they are more
519     // accurate than `decode_frame_rate` and `render_frame_rate`.
520     // The latter two are calculated on a momentary basis.
521     const double total_frames_duration_sec_double =
522         static_cast<double>(receive_stats.total_frames_duration_ms) / 1000.0;
523     if (total_frames_duration_sec_double > 0) {
524       decode_frame_rate_ = static_cast<double>(receive_stats.frames_decoded) /
525                            total_frames_duration_sec_double;
526       render_frame_rate_ = static_cast<double>(receive_stats.frames_rendered) /
527                            total_frames_duration_sec_double;
528     }
529 
530     // Freeze metrics.
531     freeze_count_ = receive_stats.freeze_count;
532     total_freezes_duration_ms_ = receive_stats.total_freezes_duration_ms;
533     total_frames_duration_ms_ = receive_stats.total_frames_duration_ms;
534     sum_squared_frame_durations_ = receive_stats.sum_squared_frame_durations;
535   }
536 
537   if (audio_receive_stream_ != nullptr) {
538     AudioReceiveStreamInterface::Stats receive_stats =
539         audio_receive_stream_->GetStats(/*get_and_clear_legacy_stats=*/true);
540     audio_expand_rate_.AddSample(receive_stats.expand_rate);
541     audio_accelerate_rate_.AddSample(receive_stats.accelerate_rate);
542     audio_jitter_buffer_ms_.AddSample(receive_stats.jitter_buffer_ms);
543   }
544 
545   memory_usage_.AddSample(rtc::GetProcessResidentSizeBytes());
546 }
547 
CompareFrames()548 bool VideoAnalyzer::CompareFrames() {
549   if (AllFramesRecorded())
550     return false;
551 
552   FrameComparison comparison;
553 
554   if (!PopComparison(&comparison)) {
555     // Wait until new comparison task is available, or test is done.
556     // If done, wake up remaining threads waiting.
557     comparison_available_event_.Wait(TimeDelta::Seconds(1));
558     if (AllFramesRecorded()) {
559       comparison_available_event_.Set();
560       return false;
561     }
562     return true;  // Try again.
563   }
564 
565   StartExcludingCpuThreadTime();
566 
567   PerformFrameComparison(comparison);
568 
569   StopExcludingCpuThreadTime();
570 
571   if (FrameProcessed()) {
572     done_.Set();
573     comparison_available_event_.Set();
574     return false;
575   }
576 
577   return true;
578 }
579 
PopComparison(VideoAnalyzer::FrameComparison * comparison)580 bool VideoAnalyzer::PopComparison(VideoAnalyzer::FrameComparison* comparison) {
581   MutexLock lock(&comparison_lock_);
582   // If AllFramesRecorded() is true, it means we have already popped
583   // frames_to_process_ frames from comparisons_, so there is no more work
584   // for this thread to be done. frames_processed_ might still be lower if
585   // all comparisons are not done, but those frames are currently being
586   // worked on by other threads.
587   if (comparisons_.empty() || AllFramesRecordedLocked())
588     return false;
589 
590   *comparison = comparisons_.front();
591   comparisons_.pop_front();
592 
593   FrameRecorded();
594   return true;
595 }
596 
FrameRecorded()597 void VideoAnalyzer::FrameRecorded() {
598   ++frames_recorded_;
599 }
600 
AllFramesRecorded()601 bool VideoAnalyzer::AllFramesRecorded() {
602   MutexLock lock(&comparison_lock_);
603   return AllFramesRecordedLocked();
604 }
605 
AllFramesRecordedLocked()606 bool VideoAnalyzer::AllFramesRecordedLocked() {
607   RTC_DCHECK(frames_recorded_ <= frames_to_process_);
608   return frames_recorded_ == frames_to_process_ ||
609          (clock_->CurrentTime() > test_end_ && comparisons_.empty()) || quit_;
610 }
611 
FrameProcessed()612 bool VideoAnalyzer::FrameProcessed() {
613   MutexLock lock(&comparison_lock_);
614   ++frames_processed_;
615   RTC_DCHECK_LE(frames_processed_, frames_to_process_);
616   return frames_processed_ == frames_to_process_ ||
617          (clock_->CurrentTime() > test_end_ && comparisons_.empty());
618 }
619 
PrintResults()620 void VideoAnalyzer::PrintResults() {
621   StopMeasuringCpuProcessTime();
622   int dropped_frames_diff;
623   {
624     MutexLock lock(&lock_);
625     dropped_frames_diff = dropped_frames_before_first_encode_ +
626                           dropped_frames_before_rendering_ + frames_.size();
627   }
628   MutexLock lock(&comparison_lock_);
629   PrintResult("psnr_dB", psnr_, Unit::kUnitless,
630               ImprovementDirection::kBiggerIsBetter);
631   PrintResult("ssim", ssim_, Unit::kUnitless,
632               ImprovementDirection::kBiggerIsBetter);
633   PrintResult("sender_time", sender_time_, Unit::kMilliseconds,
634               ImprovementDirection::kSmallerIsBetter);
635   PrintResult("receiver_time", receiver_time_, Unit::kMilliseconds,
636               ImprovementDirection::kSmallerIsBetter);
637   PrintResult("network_time", network_time_, Unit::kMilliseconds,
638               ImprovementDirection::kSmallerIsBetter);
639   PrintResult("total_delay_incl_network", end_to_end_, Unit::kMilliseconds,
640               ImprovementDirection::kSmallerIsBetter);
641   PrintResult("time_between_rendered_frames", rendered_delta_,
642               Unit::kMilliseconds, ImprovementDirection::kSmallerIsBetter);
643   PrintResult("encode_frame_rate_fps", encode_frame_rate_, Unit::kHertz,
644               ImprovementDirection::kBiggerIsBetter);
645   PrintResult("encode_time", encode_time_ms_, Unit::kMilliseconds,
646               ImprovementDirection::kSmallerIsBetter);
647   PrintResult("media_bitrate", media_bitrate_bps_ / 1000.0,
648               Unit::kKilobitsPerSecond, ImprovementDirection::kNeitherIsBetter);
649   PrintResult("fec_bitrate", fec_bitrate_bps_ / 1000.0,
650               Unit::kKilobitsPerSecond, ImprovementDirection::kNeitherIsBetter);
651   PrintResult("send_bandwidth", send_bandwidth_bps_ / 1000.0,
652               Unit::kKilobitsPerSecond, ImprovementDirection::kNeitherIsBetter);
653   PrintResult("pixels_per_frame", pixels_, Unit::kCount,
654               ImprovementDirection::kBiggerIsBetter);
655 
656   GetGlobalMetricsLogger()->LogSingleValueMetric(
657       "decode_frame_rate_fps", test_label_, decode_frame_rate_, Unit::kHertz,
658       ImprovementDirection::kBiggerIsBetter);
659   GetGlobalMetricsLogger()->LogSingleValueMetric(
660       "render_frame_rate_fps", test_label_, render_frame_rate_, Unit::kHertz,
661       ImprovementDirection::kBiggerIsBetter);
662 
663   // Record the time from the last freeze until the last rendered frame to
664   // ensure we cover the full timespan of the session. Otherwise the metric
665   // would penalize an early freeze followed by no freezes until the end.
666   time_between_freezes_.AddSample(last_render_time_ - last_unfreeze_time_ms_);
667 
668   // Freeze metrics.
669   PrintResult("time_between_freezes", time_between_freezes_,
670               Unit::kMilliseconds, ImprovementDirection::kBiggerIsBetter);
671 
672   const double freeze_count_double = static_cast<double>(freeze_count_);
673   const double total_freezes_duration_ms_double =
674       static_cast<double>(total_freezes_duration_ms_);
675   const double total_frames_duration_ms_double =
676       static_cast<double>(total_frames_duration_ms_);
677 
678   if (total_frames_duration_ms_double > 0) {
679     GetGlobalMetricsLogger()->LogSingleValueMetric(
680         "freeze_duration_ratio", test_label_,
681         total_freezes_duration_ms_double / total_frames_duration_ms_double,
682         Unit::kUnitless, ImprovementDirection::kSmallerIsBetter);
683     RTC_DCHECK_LE(total_freezes_duration_ms_double,
684                   total_frames_duration_ms_double);
685 
686     constexpr double ms_per_minute = 60 * 1000;
687     const double total_frames_duration_min =
688         total_frames_duration_ms_double / ms_per_minute;
689     if (total_frames_duration_min > 0) {
690       GetGlobalMetricsLogger()->LogSingleValueMetric(
691           "freeze_count_per_minute", test_label_,
692           freeze_count_double / total_frames_duration_min, Unit::kUnitless,
693           ImprovementDirection::kSmallerIsBetter);
694     }
695   }
696 
697   GetGlobalMetricsLogger()->LogSingleValueMetric(
698       "freeze_duration_average", test_label_,
699       freeze_count_double > 0
700           ? total_freezes_duration_ms_double / freeze_count_double
701           : 0,
702       Unit::kMilliseconds, ImprovementDirection::kSmallerIsBetter);
703 
704   if (1000 * sum_squared_frame_durations_ > 0) {
705     GetGlobalMetricsLogger()->LogSingleValueMetric(
706         "harmonic_frame_rate_fps", test_label_,
707         total_frames_duration_ms_double / (1000 * sum_squared_frame_durations_),
708         Unit::kHertz, ImprovementDirection::kBiggerIsBetter);
709   }
710 
711   if (worst_frame_) {
712     GetGlobalMetricsLogger()->LogSingleValueMetric(
713         "min_psnr_dB", test_label_, worst_frame_->psnr, Unit::kUnitless,
714         ImprovementDirection::kBiggerIsBetter);
715   }
716 
717   if (receive_stream_ != nullptr) {
718     PrintResultWithExternalMean("decode_time", mean_decode_time_ms_,
719                                 decode_time_ms_, Unit::kMilliseconds,
720                                 ImprovementDirection::kSmallerIsBetter);
721   }
722   dropped_frames_ += dropped_frames_diff;
723   GetGlobalMetricsLogger()->LogSingleValueMetric(
724       "dropped_frames", test_label_, dropped_frames_, Unit::kCount,
725       ImprovementDirection::kSmallerIsBetter);
726   GetGlobalMetricsLogger()->LogSingleValueMetric(
727       "cpu_usage_%", test_label_, GetCpuUsagePercent(), Unit::kUnitless,
728       ImprovementDirection::kSmallerIsBetter);
729 
730 #if defined(WEBRTC_WIN)
731   // On Linux and Mac in Resident Set some unused pages may be counted.
732   // Therefore this metric will depend on order in which tests are run and
733   // will be flaky.
734   PrintResult("memory_usage", memory_usage_, Unit::kBytes,
735               ImprovementDirection::kSmallerIsBetter);
736 #endif
737 
738   // Saving only the worst frame for manual analysis. Intention here is to
739   // only detect video corruptions and not to track picture quality. Thus,
740   // jpeg is used here.
741   if (absl::GetFlag(FLAGS_save_worst_frame) && worst_frame_) {
742     std::string output_dir;
743     test::GetTestArtifactsDir(&output_dir);
744     std::string output_path =
745         test::JoinFilename(output_dir, test_label_ + ".jpg");
746     RTC_LOG(LS_INFO) << "Saving worst frame to " << output_path;
747     test::JpegFrameWriter frame_writer(output_path);
748     RTC_CHECK(
749         frame_writer.WriteFrame(worst_frame_->frame, 100 /*best quality*/));
750   }
751 
752   if (audio_receive_stream_ != nullptr) {
753     PrintResult("audio_expand_rate", audio_expand_rate_, Unit::kUnitless,
754                 ImprovementDirection::kSmallerIsBetter);
755     PrintResult("audio_accelerate_rate", audio_accelerate_rate_,
756                 Unit::kUnitless, ImprovementDirection::kSmallerIsBetter);
757     PrintResult("audio_jitter_buffer", audio_jitter_buffer_ms_,
758                 Unit::kMilliseconds, ImprovementDirection::kNeitherIsBetter);
759   }
760 
761   //  Disable quality check for quick test, as quality checks may fail
762   //  because too few samples were collected.
763   if (!is_quick_test_enabled_) {
764     EXPECT_GT(psnr_.GetAverage(), avg_psnr_threshold_);
765     EXPECT_GT(ssim_.GetAverage(), avg_ssim_threshold_);
766   }
767 }
768 
PerformFrameComparison(const VideoAnalyzer::FrameComparison & comparison)769 void VideoAnalyzer::PerformFrameComparison(
770     const VideoAnalyzer::FrameComparison& comparison) {
771   // Perform expensive psnr and ssim calculations while not holding lock.
772   double psnr = -1.0;
773   double ssim = -1.0;
774   if (comparison.reference && !comparison.dropped) {
775     psnr = I420PSNR(&*comparison.reference, &*comparison.render);
776     ssim = I420SSIM(&*comparison.reference, &*comparison.render);
777   }
778 
779   MutexLock lock(&comparison_lock_);
780 
781   if (psnr >= 0.0 && (!worst_frame_ || worst_frame_->psnr > psnr)) {
782     worst_frame_.emplace(FrameWithPsnr{psnr, *comparison.render});
783   }
784 
785   if (graph_data_output_file_) {
786     samples_.push_back(Sample(comparison.dropped, comparison.input_time_ms,
787                               comparison.send_time_ms, comparison.recv_time_ms,
788                               comparison.render_time_ms,
789                               comparison.encoded_frame_size, psnr, ssim));
790   }
791   if (psnr >= 0.0)
792     psnr_.AddSample(psnr);
793   if (ssim >= 0.0)
794     ssim_.AddSample(ssim);
795 
796   if (comparison.dropped) {
797     ++dropped_frames_;
798     return;
799   }
800   if (last_unfreeze_time_ms_ == 0)
801     last_unfreeze_time_ms_ = comparison.render_time_ms;
802   if (last_render_time_ != 0) {
803     const int64_t render_delta_ms =
804         comparison.render_time_ms - last_render_time_;
805     rendered_delta_.AddSample(render_delta_ms);
806     if (last_render_delta_ms_ != 0 &&
807         render_delta_ms - last_render_delta_ms_ > 150) {
808       time_between_freezes_.AddSample(last_render_time_ -
809                                       last_unfreeze_time_ms_);
810       last_unfreeze_time_ms_ = comparison.render_time_ms;
811     }
812     last_render_delta_ms_ = render_delta_ms;
813   }
814   last_render_time_ = comparison.render_time_ms;
815 
816   sender_time_.AddSample(comparison.send_time_ms - comparison.input_time_ms);
817   if (comparison.recv_time_ms > 0) {
818     // If recv_time_ms == 0, this frame consisted of a packets which were all
819     // lost in the transport. Since we were able to render the frame, however,
820     // the dropped packets were recovered by FlexFEC. The FlexFEC recovery
821     // happens internally in Call, and we can therefore here not know which
822     // FEC packets that protected the lost media packets. Consequently, we
823     // were not able to record a meaningful recv_time_ms. We therefore skip
824     // this sample.
825     //
826     // The reasoning above does not hold for ULPFEC and RTX, as for those
827     // strategies the timestamp of the received packets is set to the
828     // timestamp of the protected/retransmitted media packet. I.e., then
829     // recv_time_ms != 0, even though the media packets were lost.
830     receiver_time_.AddSample(comparison.render_time_ms -
831                              comparison.recv_time_ms);
832     network_time_.AddSample(comparison.recv_time_ms - comparison.send_time_ms);
833   }
834   end_to_end_.AddSample(comparison.render_time_ms - comparison.input_time_ms);
835   encoded_frame_size_.AddSample(comparison.encoded_frame_size);
836 }
837 
PrintResult(absl::string_view result_type,const SamplesStatsCounter & stats,Unit unit,ImprovementDirection improvement_direction)838 void VideoAnalyzer::PrintResult(absl::string_view result_type,
839                                 const SamplesStatsCounter& stats,
840                                 Unit unit,
841                                 ImprovementDirection improvement_direction) {
842   GetGlobalMetricsLogger()->LogMetric(result_type, test_label_, stats, unit,
843                                       improvement_direction);
844 }
845 
PrintResultWithExternalMean(absl::string_view result_type,double mean,const SamplesStatsCounter & stats,Unit unit,ImprovementDirection improvement_direction)846 void VideoAnalyzer::PrintResultWithExternalMean(
847     absl::string_view result_type,
848     double mean,
849     const SamplesStatsCounter& stats,
850     Unit unit,
851     ImprovementDirection improvement_direction) {
852   // If the true mean is different than the sample mean, the sample variance is
853   // too low. The sample variance given a known mean is obtained by adding the
854   // squared error between the true mean and the sample mean.
855   double compensated_variance =
856       stats.IsEmpty()
857           ? 0.0
858           : stats.GetVariance() + pow(mean - stats.GetAverage(), 2.0);
859   GetGlobalMetricsLogger()->LogMetric(
860       result_type, test_label_,
861       Metric::Stats{.mean = mean, .stddev = std::sqrt(compensated_variance)},
862       unit, improvement_direction);
863 }
864 
PrintSamplesToFile()865 void VideoAnalyzer::PrintSamplesToFile() {
866   FILE* out = graph_data_output_file_;
867   MutexLock lock(&comparison_lock_);
868   absl::c_sort(samples_, [](const Sample& A, const Sample& B) -> bool {
869     return A.input_time_ms < B.input_time_ms;
870   });
871 
872   fprintf(out, "%s\n", graph_title_.c_str());
873   fprintf(out, "%zu\n", samples_.size());
874   fprintf(out,
875           "dropped "
876           "input_time_ms "
877           "send_time_ms "
878           "recv_time_ms "
879           "render_time_ms "
880           "encoded_frame_size "
881           "psnr "
882           "ssim "
883           "encode_time_ms\n");
884   for (const Sample& sample : samples_) {
885     fprintf(out,
886             "%d %" PRId64 " %" PRId64 " %" PRId64 " %" PRId64 " %zu %lf %lf\n",
887             sample.dropped, sample.input_time_ms, sample.send_time_ms,
888             sample.recv_time_ms, sample.render_time_ms,
889             sample.encoded_frame_size, sample.psnr, sample.ssim);
890   }
891 }
892 
AddCapturedFrameForComparison(const VideoFrame & video_frame)893 void VideoAnalyzer::AddCapturedFrameForComparison(
894     const VideoFrame& video_frame) {
895   bool must_capture = false;
896   {
897     MutexLock lock(&comparison_lock_);
898     must_capture = captured_frames_ < frames_to_process_;
899     if (must_capture) {
900       ++captured_frames_;
901     }
902   }
903   if (must_capture) {
904     MutexLock lock(&lock_);
905     frames_.push_back(video_frame);
906   }
907 }
908 
AddFrameComparison(const VideoFrame & reference,const VideoFrame & render,bool dropped,int64_t render_time_ms)909 void VideoAnalyzer::AddFrameComparison(const VideoFrame& reference,
910                                        const VideoFrame& render,
911                                        bool dropped,
912                                        int64_t render_time_ms) {
913   int64_t reference_timestamp = wrap_handler_.Unwrap(reference.timestamp());
914   int64_t send_time_ms = send_times_[reference_timestamp];
915   send_times_.erase(reference_timestamp);
916   int64_t recv_time_ms = recv_times_[reference_timestamp];
917   recv_times_.erase(reference_timestamp);
918 
919   // TODO(ivica): Make this work for > 2 streams.
920   auto it = encoded_frame_sizes_.find(reference_timestamp);
921   if (it == encoded_frame_sizes_.end())
922     it = encoded_frame_sizes_.find(reference_timestamp - 1);
923   size_t encoded_size = it == encoded_frame_sizes_.end() ? 0 : it->second;
924   if (it != encoded_frame_sizes_.end())
925     encoded_frame_sizes_.erase(it);
926 
927   MutexLock lock(&comparison_lock_);
928   if (comparisons_.size() < kMaxComparisons) {
929     comparisons_.push_back(FrameComparison(
930         reference, render, dropped, reference.ntp_time_ms(), send_time_ms,
931         recv_time_ms, render_time_ms, encoded_size));
932   } else {
933     comparisons_.push_back(FrameComparison(dropped, reference.ntp_time_ms(),
934                                            send_time_ms, recv_time_ms,
935                                            render_time_ms, encoded_size));
936   }
937   comparison_available_event_.Set();
938 }
939 
FrameComparison()940 VideoAnalyzer::FrameComparison::FrameComparison()
941     : dropped(false),
942       input_time_ms(0),
943       send_time_ms(0),
944       recv_time_ms(0),
945       render_time_ms(0),
946       encoded_frame_size(0) {}
947 
FrameComparison(const VideoFrame & reference,const VideoFrame & render,bool dropped,int64_t input_time_ms,int64_t send_time_ms,int64_t recv_time_ms,int64_t render_time_ms,size_t encoded_frame_size)948 VideoAnalyzer::FrameComparison::FrameComparison(const VideoFrame& reference,
949                                                 const VideoFrame& render,
950                                                 bool dropped,
951                                                 int64_t input_time_ms,
952                                                 int64_t send_time_ms,
953                                                 int64_t recv_time_ms,
954                                                 int64_t render_time_ms,
955                                                 size_t encoded_frame_size)
956     : reference(reference),
957       render(render),
958       dropped(dropped),
959       input_time_ms(input_time_ms),
960       send_time_ms(send_time_ms),
961       recv_time_ms(recv_time_ms),
962       render_time_ms(render_time_ms),
963       encoded_frame_size(encoded_frame_size) {}
964 
FrameComparison(bool dropped,int64_t input_time_ms,int64_t send_time_ms,int64_t recv_time_ms,int64_t render_time_ms,size_t encoded_frame_size)965 VideoAnalyzer::FrameComparison::FrameComparison(bool dropped,
966                                                 int64_t input_time_ms,
967                                                 int64_t send_time_ms,
968                                                 int64_t recv_time_ms,
969                                                 int64_t render_time_ms,
970                                                 size_t encoded_frame_size)
971     : dropped(dropped),
972       input_time_ms(input_time_ms),
973       send_time_ms(send_time_ms),
974       recv_time_ms(recv_time_ms),
975       render_time_ms(render_time_ms),
976       encoded_frame_size(encoded_frame_size) {}
977 
Sample(int dropped,int64_t input_time_ms,int64_t send_time_ms,int64_t recv_time_ms,int64_t render_time_ms,size_t encoded_frame_size,double psnr,double ssim)978 VideoAnalyzer::Sample::Sample(int dropped,
979                               int64_t input_time_ms,
980                               int64_t send_time_ms,
981                               int64_t recv_time_ms,
982                               int64_t render_time_ms,
983                               size_t encoded_frame_size,
984                               double psnr,
985                               double ssim)
986     : dropped(dropped),
987       input_time_ms(input_time_ms),
988       send_time_ms(send_time_ms),
989       recv_time_ms(recv_time_ms),
990       render_time_ms(render_time_ms),
991       encoded_frame_size(encoded_frame_size),
992       psnr(psnr),
993       ssim(ssim) {}
994 
CapturedFrameForwarder(VideoAnalyzer * analyzer,Clock * clock,int frames_to_capture,TimeDelta test_duration)995 VideoAnalyzer::CapturedFrameForwarder::CapturedFrameForwarder(
996     VideoAnalyzer* analyzer,
997     Clock* clock,
998     int frames_to_capture,
999     TimeDelta test_duration)
1000     : analyzer_(analyzer),
1001       send_stream_input_(nullptr),
1002       video_source_(nullptr),
1003       clock_(clock),
1004       captured_frames_(0),
1005       frames_to_capture_(frames_to_capture),
1006       test_end_(clock->CurrentTime() + test_duration) {}
1007 
SetSource(VideoSourceInterface<VideoFrame> * video_source)1008 void VideoAnalyzer::CapturedFrameForwarder::SetSource(
1009     VideoSourceInterface<VideoFrame>* video_source) {
1010   video_source_ = video_source;
1011 }
1012 
OnFrame(const VideoFrame & video_frame)1013 void VideoAnalyzer::CapturedFrameForwarder::OnFrame(
1014     const VideoFrame& video_frame) {
1015   VideoFrame copy = video_frame;
1016   // Frames from the capturer does not have a rtp timestamp.
1017   // Create one so it can be used for comparison.
1018   RTC_DCHECK_EQ(0, video_frame.timestamp());
1019   if (video_frame.ntp_time_ms() == 0)
1020     copy.set_ntp_time_ms(clock_->CurrentNtpInMilliseconds());
1021   copy.set_timestamp(copy.ntp_time_ms() * 90);
1022   analyzer_->AddCapturedFrameForComparison(copy);
1023   MutexLock lock(&lock_);
1024   ++captured_frames_;
1025   if (send_stream_input_ && clock_->CurrentTime() <= test_end_ &&
1026       captured_frames_ <= frames_to_capture_) {
1027     send_stream_input_->OnFrame(copy);
1028   }
1029 }
1030 
AddOrUpdateSink(rtc::VideoSinkInterface<VideoFrame> * sink,const rtc::VideoSinkWants & wants)1031 void VideoAnalyzer::CapturedFrameForwarder::AddOrUpdateSink(
1032     rtc::VideoSinkInterface<VideoFrame>* sink,
1033     const rtc::VideoSinkWants& wants) {
1034   {
1035     MutexLock lock(&lock_);
1036     RTC_DCHECK(!send_stream_input_ || send_stream_input_ == sink);
1037     send_stream_input_ = sink;
1038   }
1039   if (video_source_) {
1040     video_source_->AddOrUpdateSink(this, wants);
1041   }
1042 }
1043 
RemoveSink(rtc::VideoSinkInterface<VideoFrame> * sink)1044 void VideoAnalyzer::CapturedFrameForwarder::RemoveSink(
1045     rtc::VideoSinkInterface<VideoFrame>* sink) {
1046   MutexLock lock(&lock_);
1047   RTC_DCHECK(sink == send_stream_input_);
1048   send_stream_input_ = nullptr;
1049 }
1050 
1051 }  // namespace webrtc
1052