1 // Copyright 2014 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.
4 //
5 // This program benchmarks the theoretical throughput of the cast library.
6 // It runs using a fake clock, simulated network and fake codecs. This allows
7 // tests to run much faster than real time.
8 // To run the program, run:
9 // $ ./out/Release/cast_benchmarks | tee benchmarkoutput.asc
10 // This may take a while, when it is done, you can view the data with
11 // meshlab by running:
12 // $ meshlab benchmarkoutput.asc
13 // After starting meshlab, turn on Render->Show Axis. The red axis will
14 // represent bandwidth (in megabits) the blue axis will be packet drop
15 // (in percent) and the green axis will be latency (in milliseconds).
16 //
17 // This program can also be used for profiling. On linux it has
18 // built-in support for this. Simply set the environment variable
19 // PROFILE_FILE before running it, like so:
20 // $ export PROFILE_FILE=cast_benchmark.profile
21 // Then after running the program, you can view the profile with:
22 // $ pprof ./out/Release/cast_benchmarks $PROFILE_FILE --gv
23
24 #include <math.h>
25 #include <stdint.h>
26
27 #include <map>
28 #include <vector>
29
30 #include "base/at_exit.h"
31 #include "base/bind.h"
32 #include "base/bind_helpers.h"
33 #include "base/command_line.h"
34 #include "base/debug/profiler.h"
35 #include "base/stl_util.h"
36 #include "base/strings/string_number_conversions.h"
37 #include "base/strings/stringprintf.h"
38 #include "base/test/simple_test_tick_clock.h"
39 #include "base/threading/thread.h"
40 #include "base/time/tick_clock.h"
41 #include "media/base/audio_bus.h"
42 #include "media/base/video_frame.h"
43 #include "media/cast/cast_config.h"
44 #include "media/cast/cast_environment.h"
45 #include "media/cast/cast_receiver.h"
46 #include "media/cast/cast_sender.h"
47 #include "media/cast/logging/simple_event_subscriber.h"
48 #include "media/cast/net/cast_transport_config.h"
49 #include "media/cast/net/cast_transport_defines.h"
50 #include "media/cast/net/cast_transport_sender.h"
51 #include "media/cast/net/cast_transport_sender_impl.h"
52 #include "media/cast/test/fake_single_thread_task_runner.h"
53 #include "media/cast/test/loopback_transport.h"
54 #include "media/cast/test/skewed_single_thread_task_runner.h"
55 #include "media/cast/test/skewed_tick_clock.h"
56 #include "media/cast/test/utility/audio_utility.h"
57 #include "media/cast/test/utility/default_config.h"
58 #include "media/cast/test/utility/test_util.h"
59 #include "media/cast/test/utility/udp_proxy.h"
60 #include "media/cast/test/utility/video_utility.h"
61 #include "testing/gtest/include/gtest/gtest.h"
62
63 namespace media {
64 namespace cast {
65
66 namespace {
67
68 static const int64 kStartMillisecond = INT64_C(1245);
69 static const int kAudioChannels = 2;
70 static const int kVideoHdWidth = 1280;
71 static const int kVideoHdHeight = 720;
72 static const int kTargetPlayoutDelayMs = 300;
73
74 // The tests are commonly implemented with |kFrameTimerMs| RunTask function;
75 // a normal video is 30 fps hence the 33 ms between frames.
76 static const int kFrameTimerMs = 33;
77
UpdateCastTransportStatus(CastTransportStatus status)78 void UpdateCastTransportStatus(CastTransportStatus status) {
79 bool result = (status == TRANSPORT_AUDIO_INITIALIZED ||
80 status == TRANSPORT_VIDEO_INITIALIZED);
81 EXPECT_TRUE(result);
82 }
83
AudioInitializationStatus(CastInitializationStatus status)84 void AudioInitializationStatus(CastInitializationStatus status) {
85 EXPECT_EQ(STATUS_AUDIO_INITIALIZED, status);
86 }
87
VideoInitializationStatus(CastInitializationStatus status)88 void VideoInitializationStatus(CastInitializationStatus status) {
89 EXPECT_EQ(STATUS_VIDEO_INITIALIZED, status);
90 }
91
IgnoreRawEvents(const std::vector<PacketEvent> & packet_events,const std::vector<FrameEvent> & frame_events)92 void IgnoreRawEvents(const std::vector<PacketEvent>& packet_events,
93 const std::vector<FrameEvent>& frame_events) {
94 }
95
96 } // namespace
97
98 // Wraps a CastTransportSender and records some statistics about
99 // the data that goes through it.
100 class CastTransportSenderWrapper : public CastTransportSender {
101 public:
102 // Takes ownership of |transport|.
Init(CastTransportSender * transport,uint64 * encoded_video_bytes,uint64 * encoded_audio_bytes)103 void Init(CastTransportSender* transport,
104 uint64* encoded_video_bytes,
105 uint64* encoded_audio_bytes) {
106 transport_.reset(transport);
107 encoded_video_bytes_ = encoded_video_bytes;
108 encoded_audio_bytes_ = encoded_audio_bytes;
109 }
110
InitializeAudio(const CastTransportRtpConfig & config,const RtcpCastMessageCallback & cast_message_cb,const RtcpRttCallback & rtt_cb)111 virtual void InitializeAudio(
112 const CastTransportRtpConfig& config,
113 const RtcpCastMessageCallback& cast_message_cb,
114 const RtcpRttCallback& rtt_cb) OVERRIDE {
115 audio_ssrc_ = config.ssrc;
116 transport_->InitializeAudio(config, cast_message_cb, rtt_cb);
117 }
118
InitializeVideo(const CastTransportRtpConfig & config,const RtcpCastMessageCallback & cast_message_cb,const RtcpRttCallback & rtt_cb)119 virtual void InitializeVideo(
120 const CastTransportRtpConfig& config,
121 const RtcpCastMessageCallback& cast_message_cb,
122 const RtcpRttCallback& rtt_cb) OVERRIDE {
123 video_ssrc_ = config.ssrc;
124 transport_->InitializeVideo(config, cast_message_cb, rtt_cb);
125 }
126
InsertFrame(uint32 ssrc,const EncodedFrame & frame)127 virtual void InsertFrame(uint32 ssrc,
128 const EncodedFrame& frame) OVERRIDE {
129 if (ssrc == audio_ssrc_) {
130 *encoded_audio_bytes_ += frame.data.size();
131 } else if (ssrc == video_ssrc_) {
132 *encoded_video_bytes_ += frame.data.size();
133 }
134 transport_->InsertFrame(ssrc, frame);
135 }
136
SendSenderReport(uint32 ssrc,base::TimeTicks current_time,uint32 current_time_as_rtp_timestamp)137 virtual void SendSenderReport(
138 uint32 ssrc,
139 base::TimeTicks current_time,
140 uint32 current_time_as_rtp_timestamp) OVERRIDE {
141 transport_->SendSenderReport(ssrc,
142 current_time,
143 current_time_as_rtp_timestamp);
144 }
145
CancelSendingFrames(uint32 ssrc,const std::vector<uint32> & frame_ids)146 virtual void CancelSendingFrames(
147 uint32 ssrc,
148 const std::vector<uint32>& frame_ids) OVERRIDE {
149 transport_->CancelSendingFrames(ssrc, frame_ids);
150 }
151
ResendFrameForKickstart(uint32 ssrc,uint32 frame_id)152 virtual void ResendFrameForKickstart(uint32 ssrc,
153 uint32 frame_id) OVERRIDE {
154 transport_->ResendFrameForKickstart(ssrc, frame_id);
155 }
156
PacketReceiverForTesting()157 virtual PacketReceiverCallback PacketReceiverForTesting() OVERRIDE {
158 return transport_->PacketReceiverForTesting();
159 }
160
161 private:
162 scoped_ptr<CastTransportSender> transport_;
163 uint32 audio_ssrc_, video_ssrc_;
164 uint64* encoded_video_bytes_;
165 uint64* encoded_audio_bytes_;
166 };
167
168 struct MeasuringPoint {
MeasuringPointmedia::cast::MeasuringPoint169 MeasuringPoint(double bitrate_, double latency_, double percent_packet_drop_)
170 : bitrate(bitrate_),
171 latency(latency_),
172 percent_packet_drop(percent_packet_drop_) {}
operator <=media::cast::MeasuringPoint173 bool operator<=(const MeasuringPoint& other) const {
174 return bitrate >= other.bitrate && latency <= other.latency &&
175 percent_packet_drop <= other.percent_packet_drop;
176 }
operator >=media::cast::MeasuringPoint177 bool operator>=(const MeasuringPoint& other) const {
178 return bitrate <= other.bitrate && latency >= other.latency &&
179 percent_packet_drop >= other.percent_packet_drop;
180 }
181
AsStringmedia::cast::MeasuringPoint182 std::string AsString() const {
183 return base::StringPrintf(
184 "%f Mbit/s %f ms %f %% ", bitrate, latency, percent_packet_drop);
185 }
186
187 double bitrate;
188 double latency;
189 double percent_packet_drop;
190 };
191
192 class RunOneBenchmark {
193 public:
RunOneBenchmark()194 RunOneBenchmark()
195 : start_time_(),
196 task_runner_(new test::FakeSingleThreadTaskRunner(&testing_clock_)),
197 testing_clock_sender_(new test::SkewedTickClock(&testing_clock_)),
198 task_runner_sender_(
199 new test::SkewedSingleThreadTaskRunner(task_runner_)),
200 testing_clock_receiver_(new test::SkewedTickClock(&testing_clock_)),
201 task_runner_receiver_(
202 new test::SkewedSingleThreadTaskRunner(task_runner_)),
203 cast_environment_sender_(new CastEnvironment(
204 scoped_ptr<base::TickClock>(testing_clock_sender_).Pass(),
205 task_runner_sender_,
206 task_runner_sender_,
207 task_runner_sender_)),
208 cast_environment_receiver_(new CastEnvironment(
209 scoped_ptr<base::TickClock>(testing_clock_receiver_).Pass(),
210 task_runner_receiver_,
211 task_runner_receiver_,
212 task_runner_receiver_)),
213 receiver_to_sender_(cast_environment_receiver_),
214 sender_to_receiver_(cast_environment_sender_),
215 video_bytes_encoded_(0),
216 audio_bytes_encoded_(0),
217 frames_sent_(0) {
218 testing_clock_.Advance(
219 base::TimeDelta::FromMilliseconds(kStartMillisecond));
220 }
221
Configure(Codec video_codec,Codec audio_codec,int audio_sampling_frequency,int max_number_of_video_buffers_used)222 void Configure(Codec video_codec,
223 Codec audio_codec,
224 int audio_sampling_frequency,
225 int max_number_of_video_buffers_used) {
226 audio_sender_config_.ssrc = 1;
227 audio_sender_config_.incoming_feedback_ssrc = 2;
228 audio_sender_config_.max_playout_delay =
229 base::TimeDelta::FromMilliseconds(kTargetPlayoutDelayMs);
230 audio_sender_config_.rtp_payload_type = 96;
231 audio_sender_config_.use_external_encoder = false;
232 audio_sender_config_.frequency = audio_sampling_frequency;
233 audio_sender_config_.channels = kAudioChannels;
234 audio_sender_config_.bitrate = kDefaultAudioEncoderBitrate;
235 audio_sender_config_.codec = audio_codec;
236
237 audio_receiver_config_.feedback_ssrc =
238 audio_sender_config_.incoming_feedback_ssrc;
239 audio_receiver_config_.incoming_ssrc = audio_sender_config_.ssrc;
240 audio_receiver_config_.rtp_payload_type =
241 audio_sender_config_.rtp_payload_type;
242 audio_receiver_config_.frequency = audio_sender_config_.frequency;
243 audio_receiver_config_.channels = kAudioChannels;
244 audio_receiver_config_.max_frame_rate = 100;
245 audio_receiver_config_.codec = audio_sender_config_.codec;
246 audio_receiver_config_.rtp_max_delay_ms = kTargetPlayoutDelayMs;
247
248 video_sender_config_.ssrc = 3;
249 video_sender_config_.incoming_feedback_ssrc = 4;
250 video_sender_config_.max_playout_delay =
251 base::TimeDelta::FromMilliseconds(kTargetPlayoutDelayMs);
252 video_sender_config_.rtp_payload_type = 97;
253 video_sender_config_.use_external_encoder = false;
254 video_sender_config_.width = kVideoHdWidth;
255 video_sender_config_.height = kVideoHdHeight;
256 #if 0
257 video_sender_config_.max_bitrate = 10000000; // 10Mbit max
258 video_sender_config_.min_bitrate = 1000000; // 1Mbit min
259 video_sender_config_.start_bitrate = 1000000; // 1Mbit start
260 #else
261 video_sender_config_.max_bitrate = 4000000; // 4Mbit all the time
262 video_sender_config_.min_bitrate = 4000000;
263 video_sender_config_.start_bitrate = 4000000;
264 #endif
265 video_sender_config_.max_qp = 56;
266 video_sender_config_.min_qp = 4;
267 video_sender_config_.max_frame_rate = 30;
268 video_sender_config_.max_number_of_video_buffers_used =
269 max_number_of_video_buffers_used;
270 video_sender_config_.codec = video_codec;
271
272 video_receiver_config_.feedback_ssrc =
273 video_sender_config_.incoming_feedback_ssrc;
274 video_receiver_config_.incoming_ssrc = video_sender_config_.ssrc;
275 video_receiver_config_.rtp_payload_type =
276 video_sender_config_.rtp_payload_type;
277 video_receiver_config_.codec = video_sender_config_.codec;
278 video_receiver_config_.frequency = kVideoFrequency;
279 video_receiver_config_.channels = 1;
280 video_receiver_config_.max_frame_rate = 100;
281 video_receiver_config_.rtp_max_delay_ms = kTargetPlayoutDelayMs;
282 }
283
SetSenderClockSkew(double skew,base::TimeDelta offset)284 void SetSenderClockSkew(double skew, base::TimeDelta offset) {
285 testing_clock_sender_->SetSkew(skew, offset);
286 task_runner_sender_->SetSkew(1.0 / skew);
287 }
288
SetReceiverClockSkew(double skew,base::TimeDelta offset)289 void SetReceiverClockSkew(double skew, base::TimeDelta offset) {
290 testing_clock_receiver_->SetSkew(skew, offset);
291 task_runner_receiver_->SetSkew(1.0 / skew);
292 }
293
Create(const MeasuringPoint & p)294 void Create(const MeasuringPoint& p) {
295 cast_receiver_ = CastReceiver::Create(cast_environment_receiver_,
296 audio_receiver_config_,
297 video_receiver_config_,
298 &receiver_to_sender_);
299 net::IPEndPoint dummy_endpoint;
300 transport_sender_.Init(
301 new CastTransportSenderImpl(
302 NULL,
303 testing_clock_sender_,
304 dummy_endpoint,
305 make_scoped_ptr(new base::DictionaryValue),
306 base::Bind(&UpdateCastTransportStatus),
307 base::Bind(&IgnoreRawEvents),
308 base::TimeDelta::FromSeconds(1),
309 task_runner_sender_,
310 &sender_to_receiver_),
311 &video_bytes_encoded_,
312 &audio_bytes_encoded_);
313
314 cast_sender_ =
315 CastSender::Create(cast_environment_sender_, &transport_sender_);
316
317 // Initializing audio and video senders.
318 cast_sender_->InitializeAudio(audio_sender_config_,
319 base::Bind(&AudioInitializationStatus));
320 cast_sender_->InitializeVideo(video_sender_config_,
321 base::Bind(&VideoInitializationStatus),
322 CreateDefaultVideoEncodeAcceleratorCallback(),
323 CreateDefaultVideoEncodeMemoryCallback());
324
325 receiver_to_sender_.Initialize(
326 CreateSimplePipe(p).Pass(),
327 transport_sender_.PacketReceiverForTesting(),
328 task_runner_, &testing_clock_);
329 sender_to_receiver_.Initialize(
330 CreateSimplePipe(p).Pass(), cast_receiver_->packet_receiver(),
331 task_runner_, &testing_clock_);
332 }
333
~RunOneBenchmark()334 virtual ~RunOneBenchmark() {
335 cast_sender_.reset();
336 cast_receiver_.reset();
337 task_runner_->RunTasks();
338 }
339
SendFakeVideoFrame()340 void SendFakeVideoFrame() {
341 frames_sent_++;
342 cast_sender_->video_frame_input()->InsertRawVideoFrame(
343 media::VideoFrame::CreateBlackFrame(gfx::Size(2, 2)),
344 testing_clock_sender_->NowTicks());
345 }
346
RunTasks(int ms)347 void RunTasks(int ms) {
348 task_runner_->Sleep(base::TimeDelta::FromMilliseconds(ms));
349 }
350
BasicPlayerGotVideoFrame(const scoped_refptr<media::VideoFrame> & video_frame,const base::TimeTicks & render_time,bool continuous)351 void BasicPlayerGotVideoFrame(
352 const scoped_refptr<media::VideoFrame>& video_frame,
353 const base::TimeTicks& render_time,
354 bool continuous) {
355 video_ticks_.push_back(
356 std::make_pair(testing_clock_receiver_->NowTicks(), render_time));
357 cast_receiver_->RequestDecodedVideoFrame(base::Bind(
358 &RunOneBenchmark::BasicPlayerGotVideoFrame, base::Unretained(this)));
359 }
360
BasicPlayerGotAudioFrame(scoped_ptr<AudioBus> audio_bus,const base::TimeTicks & playout_time,bool is_continuous)361 void BasicPlayerGotAudioFrame(scoped_ptr<AudioBus> audio_bus,
362 const base::TimeTicks& playout_time,
363 bool is_continuous) {
364 audio_ticks_.push_back(
365 std::make_pair(testing_clock_receiver_->NowTicks(), playout_time));
366 cast_receiver_->RequestDecodedAudioFrame(base::Bind(
367 &RunOneBenchmark::BasicPlayerGotAudioFrame, base::Unretained(this)));
368 }
369
StartBasicPlayer()370 void StartBasicPlayer() {
371 cast_receiver_->RequestDecodedVideoFrame(base::Bind(
372 &RunOneBenchmark::BasicPlayerGotVideoFrame, base::Unretained(this)));
373 cast_receiver_->RequestDecodedAudioFrame(base::Bind(
374 &RunOneBenchmark::BasicPlayerGotAudioFrame, base::Unretained(this)));
375 }
376
CreateSimplePipe(const MeasuringPoint & p)377 scoped_ptr<test::PacketPipe> CreateSimplePipe(const MeasuringPoint& p) {
378 scoped_ptr<test::PacketPipe> pipe = test::NewBuffer(65536, p.bitrate);
379 pipe->AppendToPipe(
380 test::NewRandomDrop(p.percent_packet_drop / 100.0).Pass());
381 pipe->AppendToPipe(test::NewConstantDelay(p.latency / 1000.0));
382 return pipe.Pass();
383 }
384
Run(const MeasuringPoint & p)385 void Run(const MeasuringPoint& p) {
386 available_bitrate_ = p.bitrate;
387 Configure(
388 CODEC_VIDEO_FAKE, CODEC_AUDIO_PCM16, 32000, 1);
389 Create(p);
390 StartBasicPlayer();
391
392 for (int frame = 0; frame < 1000; frame++) {
393 SendFakeVideoFrame();
394 RunTasks(kFrameTimerMs);
395 }
396 RunTasks(100 * kFrameTimerMs); // Empty the pipeline.
397 VLOG(1) << "=============INPUTS============";
398 VLOG(1) << "Bitrate: " << p.bitrate << " mbit/s";
399 VLOG(1) << "Latency: " << p.latency << " ms";
400 VLOG(1) << "Packet drop drop: " << p.percent_packet_drop << "%";
401 VLOG(1) << "=============OUTPUTS============";
402 VLOG(1) << "Frames lost: " << frames_lost();
403 VLOG(1) << "Late frames: " << late_frames();
404 VLOG(1) << "Playout margin: " << frame_playout_buffer().AsString();
405 VLOG(1) << "Video bandwidth used: " << video_bandwidth() << " mbit/s ("
406 << (video_bandwidth() * 100 / desired_video_bitrate()) << "%)";
407 VLOG(1) << "Good run: " << SimpleGood();
408 }
409
410 // Metrics
frames_lost() const411 int frames_lost() const { return frames_sent_ - video_ticks_.size(); }
412
late_frames() const413 int late_frames() const {
414 int frames = 0;
415 // Ignore the first two seconds of video or so.
416 for (size_t i = 60; i < video_ticks_.size(); i++) {
417 if (video_ticks_[i].first > video_ticks_[i].second) {
418 frames++;
419 }
420 }
421 return frames;
422 }
423
frame_playout_buffer() const424 test::MeanAndError frame_playout_buffer() const {
425 std::vector<double> values;
426 for (size_t i = 0; i < video_ticks_.size(); i++) {
427 values.push_back(
428 (video_ticks_[i].second - video_ticks_[i].first).InMillisecondsF());
429 }
430 return test::MeanAndError(values);
431 }
432
433 // Mbits per second
video_bandwidth() const434 double video_bandwidth() const {
435 double seconds = (kFrameTimerMs * frames_sent_ / 1000.0);
436 double megabits = video_bytes_encoded_ * 8 / 1000000.0;
437 return megabits / seconds;
438 }
439
440 // Mbits per second
audio_bandwidth() const441 double audio_bandwidth() const {
442 double seconds = (kFrameTimerMs * frames_sent_ / 1000.0);
443 double megabits = audio_bytes_encoded_ * 8 / 1000000.0;
444 return megabits / seconds;
445 }
446
desired_video_bitrate()447 double desired_video_bitrate() {
448 return std::min<double>(available_bitrate_,
449 video_sender_config_.max_bitrate / 1000000.0);
450 }
451
SimpleGood()452 bool SimpleGood() {
453 return frames_lost() <= 1 && late_frames() <= 1 &&
454 video_bandwidth() > desired_video_bitrate() * 0.8 &&
455 video_bandwidth() < desired_video_bitrate() * 1.2;
456 }
457
458 private:
459 FrameReceiverConfig audio_receiver_config_;
460 FrameReceiverConfig video_receiver_config_;
461 AudioSenderConfig audio_sender_config_;
462 VideoSenderConfig video_sender_config_;
463
464 base::TimeTicks start_time_;
465
466 // These run in "test time"
467 base::SimpleTestTickClock testing_clock_;
468 scoped_refptr<test::FakeSingleThreadTaskRunner> task_runner_;
469
470 // These run on the sender timeline.
471 test::SkewedTickClock* testing_clock_sender_;
472 scoped_refptr<test::SkewedSingleThreadTaskRunner> task_runner_sender_;
473
474 // These run on the receiver timeline.
475 test::SkewedTickClock* testing_clock_receiver_;
476 scoped_refptr<test::SkewedSingleThreadTaskRunner> task_runner_receiver_;
477
478 scoped_refptr<CastEnvironment> cast_environment_sender_;
479 scoped_refptr<CastEnvironment> cast_environment_receiver_;
480
481 LoopBackTransport receiver_to_sender_;
482 LoopBackTransport sender_to_receiver_;
483 CastTransportSenderWrapper transport_sender_;
484 uint64 video_bytes_encoded_;
485 uint64 audio_bytes_encoded_;
486
487 scoped_ptr<CastReceiver> cast_receiver_;
488 scoped_ptr<CastSender> cast_sender_;
489
490 int frames_sent_;
491 double available_bitrate_;
492 std::vector<std::pair<base::TimeTicks, base::TimeTicks> > audio_ticks_;
493 std::vector<std::pair<base::TimeTicks, base::TimeTicks> > video_ticks_;
494 };
495
496 enum CacheResult { FOUND_TRUE, FOUND_FALSE, NOT_FOUND };
497
498 template <class T>
499 class BenchmarkCache {
500 public:
Lookup(const T & x)501 CacheResult Lookup(const T& x) {
502 base::AutoLock key(lock_);
503 for (size_t i = 0; i < results_.size(); i++) {
504 if (results_[i].second) {
505 if (x <= results_[i].first) {
506 VLOG(2) << "TRUE because: " << x.AsString()
507 << " <= " << results_[i].first.AsString();
508 return FOUND_TRUE;
509 }
510 } else {
511 if (x >= results_[i].first) {
512 VLOG(2) << "FALSE because: " << x.AsString()
513 << " >= " << results_[i].first.AsString();
514 return FOUND_FALSE;
515 }
516 }
517 }
518 return NOT_FOUND;
519 }
520
Add(const T & x,bool result)521 void Add(const T& x, bool result) {
522 base::AutoLock key(lock_);
523 VLOG(2) << "Cache Insert: " << x.AsString() << " = " << result;
524 results_.push_back(std::make_pair(x, result));
525 }
526
527 private:
528 base::Lock lock_;
529 std::vector<std::pair<T, bool> > results_;
530 };
531
532 struct SearchVariable {
SearchVariablemedia::cast::SearchVariable533 SearchVariable() : base(0.0), grade(0.0) {}
SearchVariablemedia::cast::SearchVariable534 SearchVariable(double b, double g) : base(b), grade(g) {}
blendmedia::cast::SearchVariable535 SearchVariable blend(const SearchVariable& other, double factor) {
536 CHECK_GE(factor, 0);
537 CHECK_LE(factor, 1.0);
538 return SearchVariable(base * (1 - factor) + other.base * factor,
539 grade * (1 - factor) + other.grade * factor);
540 }
valuemedia::cast::SearchVariable541 double value(double x) const { return base + grade * x; }
542 double base;
543 double grade;
544 };
545
546 struct SearchVector {
blendmedia::cast::SearchVector547 SearchVector blend(const SearchVector& other, double factor) {
548 SearchVector ret;
549 ret.bitrate = bitrate.blend(other.bitrate, factor);
550 ret.latency = latency.blend(other.latency, factor);
551 ret.packet_drop = packet_drop.blend(other.packet_drop, factor);
552 return ret;
553 }
554
averagemedia::cast::SearchVector555 SearchVector average(const SearchVector& other) {
556 return blend(other, 0.5);
557 }
558
GetMeasuringPointmedia::cast::SearchVector559 MeasuringPoint GetMeasuringPoint(double v) const {
560 return MeasuringPoint(
561 bitrate.value(-v), latency.value(v), packet_drop.value(v));
562 }
AsStringmedia::cast::SearchVector563 std::string AsString(double v) { return GetMeasuringPoint(v).AsString(); }
564
565 SearchVariable bitrate;
566 SearchVariable latency;
567 SearchVariable packet_drop;
568 };
569
570 class CastBenchmark {
571 public:
RunOnePoint(const SearchVector & v,double multiplier)572 bool RunOnePoint(const SearchVector& v, double multiplier) {
573 MeasuringPoint p = v.GetMeasuringPoint(multiplier);
574 VLOG(1) << "RUN: v = " << multiplier << " p = " << p.AsString();
575 if (p.bitrate <= 0) {
576 return false;
577 }
578 switch (cache_.Lookup(p)) {
579 case FOUND_TRUE:
580 return true;
581 case FOUND_FALSE:
582 return false;
583 case NOT_FOUND:
584 // Keep going
585 break;
586 }
587 bool result = true;
588 for (int tries = 0; tries < 3 && result; tries++) {
589 RunOneBenchmark benchmark;
590 benchmark.Run(p);
591 result &= benchmark.SimpleGood();
592 }
593 cache_.Add(p, result);
594 return result;
595 }
596
BinarySearch(SearchVector v,double accuracy)597 void BinarySearch(SearchVector v, double accuracy) {
598 double min = 0.0;
599 double max = 1.0;
600 while (RunOnePoint(v, max)) {
601 min = max;
602 max *= 2;
603 }
604
605 while (max - min > accuracy) {
606 double avg = (min + max) / 2;
607 if (RunOnePoint(v, avg)) {
608 min = avg;
609 } else {
610 max = avg;
611 }
612 }
613
614 // Print a data point to stdout.
615 base::AutoLock key(lock_);
616 MeasuringPoint p = v.GetMeasuringPoint(min);
617 fprintf(stdout, "%f %f %f\n", p.bitrate, p.latency, p.percent_packet_drop);
618 fflush(stdout);
619 }
620
SpanningSearch(int max,int x,int y,int skip,SearchVector a,SearchVector b,SearchVector c,double accuracy,std::vector<linked_ptr<base::Thread>> * threads)621 void SpanningSearch(int max,
622 int x,
623 int y,
624 int skip,
625 SearchVector a,
626 SearchVector b,
627 SearchVector c,
628 double accuracy,
629 std::vector<linked_ptr<base::Thread> >* threads) {
630 static int thread_num = 0;
631 if (x > max) return;
632 if (skip > max) {
633 if (y > x) return;
634 SearchVector ab = a.blend(b, static_cast<double>(x) / max);
635 SearchVector ac = a.blend(c, static_cast<double>(x) / max);
636 SearchVector v = ab.blend(ac, x == y ? 1.0 : static_cast<double>(y) / x);
637 thread_num++;
638 (*threads)[thread_num % threads->size()]->message_loop()->PostTask(
639 FROM_HERE,
640 base::Bind(&CastBenchmark::BinarySearch,
641 base::Unretained(this),
642 v,
643 accuracy));
644 } else {
645 skip *= 2;
646 SpanningSearch(max, x, y, skip, a, b, c, accuracy, threads);
647 SpanningSearch(max, x + skip, y + skip, skip, a, b, c, accuracy, threads);
648 SpanningSearch(max, x + skip, y, skip, a, b, c, accuracy, threads);
649 SpanningSearch(max, x, y + skip, skip, a, b, c, accuracy, threads);
650 }
651 }
652
Run()653 void Run() {
654 // Spanning search.
655
656 std::vector<linked_ptr<base::Thread> > threads;
657 for (int i = 0; i < 16; i++) {
658 threads.push_back(make_linked_ptr(new base::Thread(
659 base::StringPrintf("cast_bench_thread_%d", i))));
660 threads[i]->Start();
661 }
662
663 if (CommandLine::ForCurrentProcess()->HasSwitch("single-run")) {
664 SearchVector a;
665 a.bitrate.base = 100.0;
666 a.bitrate.grade = 1.0;
667 a.latency.grade = 1.0;
668 a.packet_drop.grade = 1.0;
669 threads[0]->message_loop()->PostTask(
670 FROM_HERE,
671 base::Bind(base::IgnoreResult(&CastBenchmark::RunOnePoint),
672 base::Unretained(this),
673 a,
674 1.0));
675 } else {
676 SearchVector a, b, c;
677 a.bitrate.base = b.bitrate.base = c.bitrate.base = 100.0;
678 a.bitrate.grade = 1.0;
679 b.latency.grade = 1.0;
680 c.packet_drop.grade = 1.0;
681
682 SpanningSearch(512,
683 0,
684 0,
685 1,
686 a,
687 b,
688 c,
689 0.01,
690 &threads);
691 }
692
693 for (size_t i = 0; i < threads.size(); i++) {
694 threads[i]->Stop();
695 }
696 }
697
698 private:
699 BenchmarkCache<MeasuringPoint> cache_;
700 base::Lock lock_;
701 };
702
703 } // namespace cast
704 } // namespace media
705
main(int argc,char ** argv)706 int main(int argc, char** argv) {
707 base::AtExitManager at_exit;
708 CommandLine::Init(argc, argv);
709 media::cast::CastBenchmark benchmark;
710 if (getenv("PROFILE_FILE")) {
711 std::string profile_file(getenv("PROFILE_FILE"));
712 base::debug::StartProfiling(profile_file);
713 benchmark.Run();
714 base::debug::StopProfiling();
715 } else {
716 benchmark.Run();
717 }
718 }
719