DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (cdf352f02ac4)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507
/*  Copyright (c) 2013 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 <string.h>

#include <list>
#include <memory>
#include <queue>
#include <vector>

#include "modules/video_coding/encoded_frame.h"
#include "modules/video_coding/packet.h"
#include "modules/video_coding/receiver.h"
#include "modules/video_coding/test/stream_generator.h"
#include "modules/video_coding/test/test_util.h"
#include "modules/video_coding/timing.h"
#include "rtc_base/checks.h"
#include "system_wrappers/include/clock.h"
#include "test/gtest.h"

namespace webrtc {

class TestVCMReceiver : public ::testing::Test {
 protected:
  TestVCMReceiver()
      : clock_(new SimulatedClock(0)),
        timing_(clock_.get()),
        receiver_(&timing_, clock_.get(), &event_factory_) {
    stream_generator_.reset(
        new StreamGenerator(0, clock_->TimeInMilliseconds()));
  }

  virtual void SetUp() { receiver_.Reset(); }

  int32_t InsertPacket(int index) {
    VCMPacket packet;
    bool packet_available = stream_generator_->GetPacket(&packet, index);
    EXPECT_TRUE(packet_available);
    if (!packet_available)
      return kGeneralError;  // Return here to avoid crashes below.
    return receiver_.InsertPacket(packet);
  }

  int32_t InsertPacketAndPop(int index) {
    VCMPacket packet;
    bool packet_available = stream_generator_->PopPacket(&packet, index);
    EXPECT_TRUE(packet_available);
    if (!packet_available)
      return kGeneralError;  // Return here to avoid crashes below.
    return receiver_.InsertPacket(packet);
  }

  int32_t InsertFrame(FrameType frame_type, bool complete) {
    int num_of_packets = complete ? 1 : 2;
    stream_generator_->GenerateFrame(
        frame_type, (frame_type != kEmptyFrame) ? num_of_packets : 0,
        (frame_type == kEmptyFrame) ? 1 : 0, clock_->TimeInMilliseconds());
    int32_t ret = InsertPacketAndPop(0);
    if (!complete) {
      // Drop the second packet.
      VCMPacket packet;
      stream_generator_->PopPacket(&packet, 0);
    }
    clock_->AdvanceTimeMilliseconds(kDefaultFramePeriodMs);
    return ret;
  }

  bool DecodeNextFrame() {
    VCMEncodedFrame* frame = receiver_.FrameForDecoding(0, false);
    if (!frame)
      return false;
    receiver_.ReleaseFrame(frame);
    return true;
  }

  std::unique_ptr<SimulatedClock> clock_;
  VCMTiming timing_;
  NullEventFactory event_factory_;
  VCMReceiver receiver_;
  std::unique_ptr<StreamGenerator> stream_generator_;
};

TEST_F(TestVCMReceiver, NonDecodableDuration_Empty) {
  // Enable NACK and with no RTT thresholds for disabling retransmission delay.
  receiver_.SetNackMode(kNack, -1, -1);
  const size_t kMaxNackListSize = 1000;
  const int kMaxPacketAgeToNack = 1000;
  const int kMaxNonDecodableDuration = 500;
  const int kMinDelayMs = 500;
  receiver_.SetNackSettings(kMaxNackListSize, kMaxPacketAgeToNack,
                            kMaxNonDecodableDuration);
  EXPECT_GE(InsertFrame(kVideoFrameKey, true), kNoError);
  // Advance time until it's time to decode the key frame.
  clock_->AdvanceTimeMilliseconds(kMinDelayMs);
  EXPECT_TRUE(DecodeNextFrame());
  bool request_key_frame = false;
  std::vector<uint16_t> nack_list = receiver_.NackList(&request_key_frame);
  EXPECT_FALSE(request_key_frame);
}

TEST_F(TestVCMReceiver, NonDecodableDuration_NoKeyFrame) {
  // Enable NACK and with no RTT thresholds for disabling retransmission delay.
  receiver_.SetNackMode(kNack, -1, -1);
  const size_t kMaxNackListSize = 1000;
  const int kMaxPacketAgeToNack = 1000;
  const int kMaxNonDecodableDuration = 500;
  receiver_.SetNackSettings(kMaxNackListSize, kMaxPacketAgeToNack,
                            kMaxNonDecodableDuration);
  const int kNumFrames = kDefaultFrameRate * kMaxNonDecodableDuration / 1000;
  for (int i = 0; i < kNumFrames; ++i) {
    EXPECT_GE(InsertFrame(kVideoFrameDelta, true), kNoError);
  }
  bool request_key_frame = false;
  std::vector<uint16_t> nack_list = receiver_.NackList(&request_key_frame);
  EXPECT_TRUE(request_key_frame);
}

TEST_F(TestVCMReceiver, NonDecodableDuration_OneIncomplete) {
  // Enable NACK and with no RTT thresholds for disabling retransmission delay.
  receiver_.SetNackMode(kNack, -1, -1);
  const size_t kMaxNackListSize = 1000;
  const int kMaxPacketAgeToNack = 1000;
  const int kMaxNonDecodableDuration = 500;
  const int kMaxNonDecodableDurationFrames =
      (kDefaultFrameRate * kMaxNonDecodableDuration + 500) / 1000;
  const int kMinDelayMs = 500;
  receiver_.SetNackSettings(kMaxNackListSize, kMaxPacketAgeToNack,
                            kMaxNonDecodableDuration);
  receiver_.SetMinReceiverDelay(kMinDelayMs);
  int64_t key_frame_inserted = clock_->TimeInMilliseconds();
  EXPECT_GE(InsertFrame(kVideoFrameKey, true), kNoError);
  // Insert an incomplete frame.
  EXPECT_GE(InsertFrame(kVideoFrameDelta, false), kNoError);
  // Insert enough frames to have too long non-decodable sequence.
  for (int i = 0; i < kMaxNonDecodableDurationFrames; ++i) {
    EXPECT_GE(InsertFrame(kVideoFrameDelta, true), kNoError);
  }
  // Advance time until it's time to decode the key frame.
  clock_->AdvanceTimeMilliseconds(kMinDelayMs - clock_->TimeInMilliseconds() -
                                  key_frame_inserted);
  EXPECT_TRUE(DecodeNextFrame());
  // Make sure we get a key frame request.
  bool request_key_frame = false;
  std::vector<uint16_t> nack_list = receiver_.NackList(&request_key_frame);
  EXPECT_TRUE(request_key_frame);
}

TEST_F(TestVCMReceiver, NonDecodableDuration_NoTrigger) {
  // Enable NACK and with no RTT thresholds for disabling retransmission delay.
  receiver_.SetNackMode(kNack, -1, -1);
  const size_t kMaxNackListSize = 1000;
  const int kMaxPacketAgeToNack = 1000;
  const int kMaxNonDecodableDuration = 500;
  const int kMaxNonDecodableDurationFrames =
      (kDefaultFrameRate * kMaxNonDecodableDuration + 500) / 1000;
  const int kMinDelayMs = 500;
  receiver_.SetNackSettings(kMaxNackListSize, kMaxPacketAgeToNack,
                            kMaxNonDecodableDuration);
  receiver_.SetMinReceiverDelay(kMinDelayMs);
  int64_t key_frame_inserted = clock_->TimeInMilliseconds();
  EXPECT_GE(InsertFrame(kVideoFrameKey, true), kNoError);
  // Insert an incomplete frame.
  EXPECT_GE(InsertFrame(kVideoFrameDelta, false), kNoError);
  // Insert all but one frame to not trigger a key frame request due to
  // too long duration of non-decodable frames.
  for (int i = 0; i < kMaxNonDecodableDurationFrames - 1; ++i) {
    EXPECT_GE(InsertFrame(kVideoFrameDelta, true), kNoError);
  }
  // Advance time until it's time to decode the key frame.
  clock_->AdvanceTimeMilliseconds(kMinDelayMs - clock_->TimeInMilliseconds() -
                                  key_frame_inserted);
  EXPECT_TRUE(DecodeNextFrame());
  // Make sure we don't get a key frame request since we haven't generated
  // enough frames.
  bool request_key_frame = false;
  std::vector<uint16_t> nack_list = receiver_.NackList(&request_key_frame);
  EXPECT_FALSE(request_key_frame);
}

TEST_F(TestVCMReceiver, NonDecodableDuration_NoTrigger2) {
  // Enable NACK and with no RTT thresholds for disabling retransmission delay.
  receiver_.SetNackMode(kNack, -1, -1);
  const size_t kMaxNackListSize = 1000;
  const int kMaxPacketAgeToNack = 1000;
  const int kMaxNonDecodableDuration = 500;
  const int kMaxNonDecodableDurationFrames =
      (kDefaultFrameRate * kMaxNonDecodableDuration + 500) / 1000;
  const int kMinDelayMs = 500;
  receiver_.SetNackSettings(kMaxNackListSize, kMaxPacketAgeToNack,
                            kMaxNonDecodableDuration);
  receiver_.SetMinReceiverDelay(kMinDelayMs);
  int64_t key_frame_inserted = clock_->TimeInMilliseconds();
  EXPECT_GE(InsertFrame(kVideoFrameKey, true), kNoError);
  // Insert enough frames to have too long non-decodable sequence, except that
  // we don't have any losses.
  for (int i = 0; i < kMaxNonDecodableDurationFrames; ++i) {
    EXPECT_GE(InsertFrame(kVideoFrameDelta, true), kNoError);
  }
  // Insert an incomplete frame.
  EXPECT_GE(InsertFrame(kVideoFrameDelta, false), kNoError);
  // Advance time until it's time to decode the key frame.
  clock_->AdvanceTimeMilliseconds(kMinDelayMs - clock_->TimeInMilliseconds() -
                                  key_frame_inserted);
  EXPECT_TRUE(DecodeNextFrame());
  // Make sure we don't get a key frame request since the non-decodable duration
  // is only one frame.
  bool request_key_frame = false;
  std::vector<uint16_t> nack_list = receiver_.NackList(&request_key_frame);
  EXPECT_FALSE(request_key_frame);
}

TEST_F(TestVCMReceiver, NonDecodableDuration_KeyFrameAfterIncompleteFrames) {
  // Enable NACK and with no RTT thresholds for disabling retransmission delay.
  receiver_.SetNackMode(kNack, -1, -1);
  const size_t kMaxNackListSize = 1000;
  const int kMaxPacketAgeToNack = 1000;
  const int kMaxNonDecodableDuration = 500;
  const int kMaxNonDecodableDurationFrames =
      (kDefaultFrameRate * kMaxNonDecodableDuration + 500) / 1000;
  const int kMinDelayMs = 500;
  receiver_.SetNackSettings(kMaxNackListSize, kMaxPacketAgeToNack,
                            kMaxNonDecodableDuration);
  receiver_.SetMinReceiverDelay(kMinDelayMs);
  int64_t key_frame_inserted = clock_->TimeInMilliseconds();
  EXPECT_GE(InsertFrame(kVideoFrameKey, true), kNoError);
  // Insert an incomplete frame.
  EXPECT_GE(InsertFrame(kVideoFrameDelta, false), kNoError);
  // Insert enough frames to have too long non-decodable sequence.
  for (int i = 0; i < kMaxNonDecodableDurationFrames; ++i) {
    EXPECT_GE(InsertFrame(kVideoFrameDelta, true), kNoError);
  }
  EXPECT_GE(InsertFrame(kVideoFrameKey, true), kNoError);
  // Advance time until it's time to decode the key frame.
  clock_->AdvanceTimeMilliseconds(kMinDelayMs - clock_->TimeInMilliseconds() -
                                  key_frame_inserted);
  EXPECT_TRUE(DecodeNextFrame());
  // Make sure we don't get a key frame request since we have a key frame
  // in the list.
  bool request_key_frame = false;
  std::vector<uint16_t> nack_list = receiver_.NackList(&request_key_frame);
  EXPECT_FALSE(request_key_frame);
}

// A simulated clock, when time elapses, will insert frames into the jitter
// buffer, based on initial settings.
class SimulatedClockWithFrames : public SimulatedClock {
 public:
  SimulatedClockWithFrames(StreamGenerator* stream_generator,
                           VCMReceiver* receiver)
      : SimulatedClock(0),
        stream_generator_(stream_generator),
        receiver_(receiver) {}
  virtual ~SimulatedClockWithFrames() {}

  // If |stop_on_frame| is true and next frame arrives between now and
  // now+|milliseconds|, the clock will be advanced to the arrival time of next
  // frame.
  // Otherwise, the clock will be advanced by |milliseconds|.
  //
  // For both cases, a frame will be inserted into the jitter buffer at the
  // instant when the clock time is timestamps_.front().arrive_time.
  //
  // Return true if some frame arrives between now and now+|milliseconds|.
  bool AdvanceTimeMilliseconds(int64_t milliseconds, bool stop_on_frame) {
    return AdvanceTimeMicroseconds(milliseconds * 1000, stop_on_frame);
  }

  bool AdvanceTimeMicroseconds(int64_t microseconds, bool stop_on_frame) {
    int64_t start_time = TimeInMicroseconds();
    int64_t end_time = start_time + microseconds;
    bool frame_injected = false;
    while (!timestamps_.empty() &&
           timestamps_.front().arrive_time <= end_time) {
      RTC_DCHECK(timestamps_.front().arrive_time >= start_time);

      SimulatedClock::AdvanceTimeMicroseconds(timestamps_.front().arrive_time -
                                              TimeInMicroseconds());
      GenerateAndInsertFrame((timestamps_.front().render_time + 500) / 1000);
      timestamps_.pop();
      frame_injected = true;

      if (stop_on_frame)
        return frame_injected;
    }

    if (TimeInMicroseconds() < end_time) {
      SimulatedClock::AdvanceTimeMicroseconds(end_time - TimeInMicroseconds());
    }
    return frame_injected;
  }

  // Input timestamps are in unit Milliseconds.
  // And |arrive_timestamps| must be positive and in increasing order.
  // |arrive_timestamps| determine when we are going to insert frames into the
  // jitter buffer.
  // |render_timestamps| are the timestamps on the frame.
  void SetFrames(const int64_t* arrive_timestamps,
                 const int64_t* render_timestamps,
                 size_t size) {
    int64_t previous_arrive_timestamp = 0;
    for (size_t i = 0; i < size; i++) {
      RTC_CHECK(arrive_timestamps[i] >= previous_arrive_timestamp);
      timestamps_.push(TimestampPair(arrive_timestamps[i] * 1000,
                                     render_timestamps[i] * 1000));
      previous_arrive_timestamp = arrive_timestamps[i];
    }
  }

 private:
  struct TimestampPair {
    TimestampPair(int64_t arrive_timestamp, int64_t render_timestamp)
        : arrive_time(arrive_timestamp), render_time(render_timestamp) {}

    int64_t arrive_time;
    int64_t render_time;
  };

  void GenerateAndInsertFrame(int64_t render_timestamp_ms) {
    VCMPacket packet;
    stream_generator_->GenerateFrame(FrameType::kVideoFrameKey,
                                     1,  // media packets
                                     0,  // empty packets
                                     render_timestamp_ms);

    bool packet_available = stream_generator_->PopPacket(&packet, 0);
    EXPECT_TRUE(packet_available);
    if (!packet_available)
      return;  // Return here to avoid crashes below.
    receiver_->InsertPacket(packet);
  }

  std::queue<TimestampPair> timestamps_;
  StreamGenerator* stream_generator_;
  VCMReceiver* receiver_;
};

// Use a SimulatedClockWithFrames
// Wait call will do either of these:
// 1. If |stop_on_frame| is true, the clock will be turned to the exact instant
// that the first frame comes and the frame will be inserted into the jitter
// buffer, or the clock will be turned to now + |max_time| if no frame comes in
// the window.
// 2. If |stop_on_frame| is false, the clock will be turn to now + |max_time|,
// and all the frames arriving between now and now + |max_time| will be
// inserted into the jitter buffer.
//
// This is used to simulate the JitterBuffer getting packets from internet as
// time elapses.

class FrameInjectEvent : public EventWrapper {
 public:
  FrameInjectEvent(SimulatedClockWithFrames* clock, bool stop_on_frame)
      : clock_(clock), stop_on_frame_(stop_on_frame) {}

  bool Set() override { return true; }

  EventTypeWrapper Wait(unsigned long max_time) override {  // NOLINT
    if (clock_->AdvanceTimeMilliseconds(max_time, stop_on_frame_) &&
        stop_on_frame_) {
      return EventTypeWrapper::kEventSignaled;
    } else {
      return EventTypeWrapper::kEventTimeout;
    }
  }

 private:
  SimulatedClockWithFrames* clock_;
  bool stop_on_frame_;
};

class VCMReceiverTimingTest : public ::testing::Test {
 protected:
  VCMReceiverTimingTest()

      : clock_(&stream_generator_, &receiver_),
        stream_generator_(0, clock_.TimeInMilliseconds()),
        timing_(&clock_),
        receiver_(
            &timing_,
            &clock_,
            std::unique_ptr<EventWrapper>(new FrameInjectEvent(&clock_, false)),
            std::unique_ptr<EventWrapper>(
                new FrameInjectEvent(&clock_, true))) {}

  virtual void SetUp() { receiver_.Reset(); }

  SimulatedClockWithFrames clock_;
  StreamGenerator stream_generator_;
  VCMTiming timing_;
  VCMReceiver receiver_;
};

// Test whether VCMReceiver::FrameForDecoding handles parameter
// |max_wait_time_ms| correctly:
// 1. The function execution should never take more than |max_wait_time_ms|.
// 2. If the function exit before now + |max_wait_time_ms|, a frame must be
//    returned.
TEST_F(VCMReceiverTimingTest, FrameForDecoding) {
  const size_t kNumFrames = 100;
  const int kFramePeriod = 40;
  int64_t arrive_timestamps[kNumFrames];
  int64_t render_timestamps[kNumFrames];

  // Construct test samples.
  // render_timestamps are the timestamps stored in the Frame;
  // arrive_timestamps controls when the Frame packet got received.
  for (size_t i = 0; i < kNumFrames; i++) {
    // Preset frame rate to 25Hz.
    // But we add a reasonable deviation to arrive_timestamps to mimic Internet
    // fluctuation.
    arrive_timestamps[i] =
        (i + 1) * kFramePeriod + (i % 10) * ((i % 2) ? 1 : -1);
    render_timestamps[i] = (i + 1) * kFramePeriod;
  }

  clock_.SetFrames(arrive_timestamps, render_timestamps, kNumFrames);

  // Record how many frames we finally get out of the receiver.
  size_t num_frames_return = 0;

  const int64_t kMaxWaitTime = 30;

  // Ideally, we should get all frames that we input in InitializeFrames.
  // In the case that FrameForDecoding kills frames by error, we rely on the
  // build bot to kill the test.
  while (num_frames_return < kNumFrames) {
    int64_t start_time = clock_.TimeInMilliseconds();
    VCMEncodedFrame* frame = receiver_.FrameForDecoding(kMaxWaitTime, false);
    int64_t end_time = clock_.TimeInMilliseconds();

    // In any case the FrameForDecoding should not wait longer than
    // max_wait_time.
    // In the case that we did not get a frame, it should have been waiting for
    // exactly max_wait_time. (By the testing samples we constructed above, we
    // are sure there is no timing error, so the only case it returns with NULL
    // is that it runs out of time.)
    if (frame) {
      receiver_.ReleaseFrame(frame);
      ++num_frames_return;
      EXPECT_GE(kMaxWaitTime, end_time - start_time);
    } else {
      EXPECT_EQ(kMaxWaitTime, end_time - start_time);
    }
  }
}

// Test whether VCMReceiver::FrameForDecoding handles parameter
// |prefer_late_decoding| and |max_wait_time_ms| correctly:
// 1. The function execution should never take more than |max_wait_time_ms|.
// 2. If the function exit before now + |max_wait_time_ms|, a frame must be
//    returned and the end time must be equal to the render timestamp - delay
//    for decoding and rendering.
TEST_F(VCMReceiverTimingTest, FrameForDecodingPreferLateDecoding) {
  const size_t kNumFrames = 100;
  const int kFramePeriod = 40;

  int64_t arrive_timestamps[kNumFrames];
  int64_t render_timestamps[kNumFrames];

  int render_delay_ms;
  int max_decode_ms;
  int dummy;
  timing_.GetTimings(&dummy, &max_decode_ms, &dummy, &dummy, &dummy, &dummy,
                     &render_delay_ms);

  // Construct test samples.
  // render_timestamps are the timestamps stored in the Frame;
  // arrive_timestamps controls when the Frame packet got received.
  for (size_t i = 0; i < kNumFrames; i++) {
    // Preset frame rate to 25Hz.
    // But we add a reasonable deviation to arrive_timestamps to mimic Internet
    // fluctuation.
    arrive_timestamps[i] =
        (i + 1) * kFramePeriod + (i % 10) * ((i % 2) ? 1 : -1);
    render_timestamps[i] = (i + 1) * kFramePeriod;
  }

  clock_.SetFrames(arrive_timestamps, render_timestamps, kNumFrames);

  // Record how many frames we finally get out of the receiver.
  size_t num_frames_return = 0;
  const int64_t kMaxWaitTime = 30;
  bool prefer_late_decoding = true;
  while (num_frames_return < kNumFrames) {
    int64_t start_time = clock_.TimeInMilliseconds();

    VCMEncodedFrame* frame =
        receiver_.FrameForDecoding(kMaxWaitTime, prefer_late_decoding);
    int64_t end_time = clock_.TimeInMilliseconds();
    if (frame) {
      EXPECT_EQ(frame->RenderTimeMs() - max_decode_ms - render_delay_ms,
                end_time);
      receiver_.ReleaseFrame(frame);
      ++num_frames_return;
    } else {
      EXPECT_EQ(kMaxWaitTime, end_time - start_time);
    }
  }
}

}  // namespace webrtc