media/audio/win/audio_low_latency_output_win_unittest.cc

   1 // Copyright (c) 2012 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 #include <windows.h>
   6 #include <mmsystem.h>
   7
   8 #include "base/basictypes.h"
   9 #include "base/environment.h"
  10 #include "base/files/file_util.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/path_service.h"
  14 #include "base/test/test_timeouts.h"
  15 #include "base/time/time.h"
  16 #include "base/win/scoped_com_initializer.h"
  17 #include "media/audio/audio_io.h"
  18 #include "media/audio/audio_manager.h"
  19 #include "media/audio/audio_unittest_util.h"
  20 #include "media/audio/mock_audio_source_callback.h"
  21 #include "media/audio/win/audio_low_latency_output_win.h"
  22 #include "media/audio/win/core_audio_util_win.h"
  23 #include "media/base/decoder_buffer.h"
  24 #include "media/base/seekable_buffer.h"
  25 #include "media/base/test_data_util.h"
  26 #include "testing/gmock/include/gmock/gmock.h"
  27 #include "testing/gmock_mutant.h"
  28 #include "testing/gtest/include/gtest/gtest.h"
  29
  30 using ::testing::_;
  31 using ::testing::AnyNumber;
  32 using ::testing::AtLeast;
  33 using ::testing::Between;
  34 using ::testing::CreateFunctor;
  35 using ::testing::DoAll;
  36 using ::testing::Gt;
  37 using ::testing::InvokeWithoutArgs;
  38 using ::testing::NotNull;
  39 using ::testing::Return;
  40 using base::win::ScopedCOMInitializer;
  41
  42 namespace media {
  43
  44 static const char kSpeechFile_16b_s_48k[] = "speech_16b_stereo_48kHz.raw";
  45 static const char kSpeechFile_16b_s_44k[] = "speech_16b_stereo_44kHz.raw";
  46 static const size_t kFileDurationMs = 20000;
  47 static const size_t kNumFileSegments = 2;
  48 static const int kBitsPerSample = 16;
  49 static const size_t kMaxDeltaSamples = 1000;
  50 static const char kDeltaTimeMsFileName[] = "delta_times_ms.txt";
  51
  52 MATCHER_P(HasValidDelay, value, "") {
  53   // It is difficult to come up with a perfect test condition for the delay
  54   // estimation. For now, verify that the produced output delay is always
  55   // larger than the selected buffer size.
  56   return arg >= value;
  57 }
  58
  59 // Used to terminate a loop from a different thread than the loop belongs to.
  60 // |loop| should be a MessageLoopProxy.
  61 ACTION_P(QuitLoop, loop) {
  62   loop->PostTask(FROM_HERE, base::MessageLoop::QuitClosure());
  63 }
  64
  65 // This audio source implementation should be used for manual tests only since
  66 // it takes about 20 seconds to play out a file.
  67 class ReadFromFileAudioSource : public AudioOutputStream::AudioSourceCallback {
  68  public:
  69   explicit ReadFromFileAudioSource(const std::string& name)
  70     : pos_(0),
  71       previous_call_time_(base::TimeTicks::Now()),
  72       text_file_(NULL),
  73       elements_to_write_(0) {
  74     // Reads a test file from media/test/data directory.
  75     file_ = ReadTestDataFile(name);
  76
  77     // Creates an array that will store delta times between callbacks.
  78     // The content of this array will be written to a text file at
  79     // destruction and can then be used for off-line analysis of the exact
  80     // timing of callbacks. The text file will be stored in media/test/data.
  81     delta_times_.reset(new int[kMaxDeltaSamples]);
  82   }
  83
  84   virtual ~ReadFromFileAudioSource() {
  85     // Get complete file path to output file in directory containing
  86     // media_unittests.exe.
  87     base::FilePath file_name;
  88     EXPECT_TRUE(PathService::Get(base::DIR_EXE, &file_name));
  89     file_name = file_name.AppendASCII(kDeltaTimeMsFileName);
  90
  91     EXPECT_TRUE(!text_file_);
  92     text_file_ = base::OpenFile(file_name, "wt");
  93     DLOG_IF(ERROR, !text_file_) << "Failed to open log file.";
  94
  95     // Write the array which contains delta times to a text file.
  96     size_t elements_written = 0;
  97     while (elements_written < elements_to_write_) {
  98       fprintf(text_file_, "%d\n", delta_times_[elements_written]);
  99       ++elements_written;
 100     }
 101
 102     base::CloseFile(text_file_);
 103   }
 104
 105   // AudioOutputStream::AudioSourceCallback implementation.
 106   virtual int OnMoreData(AudioBus* audio_bus,
 107                          uint32 total_bytes_delay) {
 108     // Store time difference between two successive callbacks in an array.
 109     // These values will be written to a file in the destructor.
 110     const base::TimeTicks now_time = base::TimeTicks::Now();
 111     const int diff = (now_time - previous_call_time_).InMilliseconds();
 112     previous_call_time_ = now_time;
 113     if (elements_to_write_ < kMaxDeltaSamples) {
 114       delta_times_[elements_to_write_] = diff;
 115       ++elements_to_write_;
 116     }
 117
 118     int max_size =
 119         audio_bus->frames() * audio_bus->channels() * kBitsPerSample / 8;
 120
 121     // Use samples read from a data file and fill up the audio buffer
 122     // provided to us in the callback.
 123     if (pos_ + static_cast<int>(max_size) > file_size())
 124       max_size = file_size() - pos_;
 125     int frames = max_size / (audio_bus->channels() * kBitsPerSample / 8);
 126     if (max_size) {
 127       audio_bus->FromInterleaved(
 128           file_->data() + pos_, frames, kBitsPerSample / 8);
 129       pos_ += max_size;
 130     }
 131     return frames;
 132   }
 133
 134   virtual void OnError(AudioOutputStream* stream) {}
 135
 136   int file_size() { return file_->data_size(); }
 137
 138  private:
 139   scoped_refptr<DecoderBuffer> file_;
 140   scoped_ptr<int[]> delta_times_;
 141   int pos_;
 142   base::TimeTicks previous_call_time_;
 143   FILE* text_file_;
 144   size_t elements_to_write_;
 145 };
 146
 147 static bool ExclusiveModeIsEnabled() {
 148   return (WASAPIAudioOutputStream::GetShareMode() ==
 149           AUDCLNT_SHAREMODE_EXCLUSIVE);
 150 }
 151
 152 static bool HasCoreAudioAndOutputDevices(AudioManager* audio_man) {
 153   // The low-latency (WASAPI-based) version requires Windows Vista or higher.
 154   // TODO(henrika): note that we use Wave today to query the number of
 155   // existing output devices.
 156   return CoreAudioUtil::IsSupported() && audio_man->HasAudioOutputDevices();
 157 }
 158
 159 // Convenience method which creates a default AudioOutputStream object but
 160 // also allows the user to modify the default settings.
 161 class AudioOutputStreamWrapper {
 162  public:
 163   explicit AudioOutputStreamWrapper(AudioManager* audio_manager)
 164       : audio_man_(audio_manager),
 165         format_(AudioParameters::AUDIO_PCM_LOW_LATENCY),
 166         bits_per_sample_(kBitsPerSample) {
 167     AudioParameters preferred_params;
 168     EXPECT_TRUE(SUCCEEDED(CoreAudioUtil::GetPreferredAudioParameters(
 169         eRender, eConsole, &preferred_params)));
 170     channel_layout_ = preferred_params.channel_layout();
 171     sample_rate_ = preferred_params.sample_rate();
 172     samples_per_packet_ = preferred_params.frames_per_buffer();
 173   }
 174
 175   ~AudioOutputStreamWrapper() {}
 176
 177   // Creates AudioOutputStream object using default parameters.
 178   AudioOutputStream* Create() {
 179     return CreateOutputStream();
 180   }
 181
 182   // Creates AudioOutputStream object using non-default parameters where the
 183   // frame size is modified.
 184   AudioOutputStream* Create(int samples_per_packet) {
 185     samples_per_packet_ = samples_per_packet;
 186     return CreateOutputStream();
 187   }
 188
 189   // Creates AudioOutputStream object using non-default parameters where the
 190   // sample rate and frame size are modified.
 191   AudioOutputStream* Create(int sample_rate, int samples_per_packet) {
 192     sample_rate_ = sample_rate;
 193     samples_per_packet_ = samples_per_packet;
 194     return CreateOutputStream();
 195   }
 196
 197   AudioParameters::Format format() const { return format_; }
 198   int channels() const { return ChannelLayoutToChannelCount(channel_layout_); }
 199   int bits_per_sample() const { return bits_per_sample_; }
 200   int sample_rate() const { return sample_rate_; }
 201   int samples_per_packet() const { return samples_per_packet_; }
 202
 203  private:
 204   AudioOutputStream* CreateOutputStream() {
 205     AudioOutputStream* aos = audio_man_->MakeAudioOutputStream(
 206         AudioParameters(format_, channel_layout_, sample_rate_,
 207                         bits_per_sample_, samples_per_packet_),
 208         std::string());
 209     EXPECT_TRUE(aos);
 210     return aos;
 211   }
 212
 213   AudioManager* audio_man_;
 214   AudioParameters::Format format_;
 215   ChannelLayout channel_layout_;
 216   int bits_per_sample_;
 217   int sample_rate_;
 218   int samples_per_packet_;
 219 };
 220
 221 // Convenience method which creates a default AudioOutputStream object.
 222 static AudioOutputStream* CreateDefaultAudioOutputStream(
 223     AudioManager* audio_manager) {
 224   AudioOutputStreamWrapper aosw(audio_manager);
 225   AudioOutputStream* aos = aosw.Create();
 226   return aos;
 227 }
 228
 229 // Verify that we can retrieve the current hardware/mixing sample rate
 230 // for the default audio device.
 231 // TODO(henrika): modify this test when we support full device enumeration.
 232 TEST(WASAPIAudioOutputStreamTest, HardwareSampleRate) {
 233   // Skip this test in exclusive mode since the resulting rate is only utilized
 234   // for shared mode streams.
 235   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 236   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()) &&
 237                           ExclusiveModeIsEnabled());
 238
 239   // Default device intended for games, system notification sounds,
 240   // and voice commands.
 241   int fs = static_cast<int>(
 242       WASAPIAudioOutputStream::HardwareSampleRate(std::string()));
 243   EXPECT_GE(fs, 0);
 244 }
 245
 246 // Test Create(), Close() calling sequence.
 247 TEST(WASAPIAudioOutputStreamTest, CreateAndClose) {
 248   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 249   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()));
 250   AudioOutputStream* aos = CreateDefaultAudioOutputStream(audio_manager.get());
 251   aos->Close();
 252 }
 253
 254 // Test Open(), Close() calling sequence.
 255 TEST(WASAPIAudioOutputStreamTest, OpenAndClose) {
 256   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 257   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()));
 258   AudioOutputStream* aos = CreateDefaultAudioOutputStream(audio_manager.get());
 259   EXPECT_TRUE(aos->Open());
 260   aos->Close();
 261 }
 262
 263 // Test Open(), Start(), Close() calling sequence.
 264 TEST(WASAPIAudioOutputStreamTest, OpenStartAndClose) {
 265   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 266   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()));
 267   AudioOutputStream* aos = CreateDefaultAudioOutputStream(audio_manager.get());
 268   EXPECT_TRUE(aos->Open());
 269   MockAudioSourceCallback source;
 270   EXPECT_CALL(source, OnError(aos))
 271       .Times(0);
 272   aos->Start(&source);
 273   aos->Close();
 274 }
 275
 276 // Test Open(), Start(), Stop(), Close() calling sequence.
 277 TEST(WASAPIAudioOutputStreamTest, OpenStartStopAndClose) {
 278   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 279   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()));
 280   AudioOutputStream* aos = CreateDefaultAudioOutputStream(audio_manager.get());
 281   EXPECT_TRUE(aos->Open());
 282   MockAudioSourceCallback source;
 283   EXPECT_CALL(source, OnError(aos))
 284       .Times(0);
 285   aos->Start(&source);
 286   aos->Stop();
 287   aos->Close();
 288 }
 289
 290 // Test SetVolume(), GetVolume()
 291 TEST(WASAPIAudioOutputStreamTest, Volume) {
 292   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 293   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()));
 294   AudioOutputStream* aos = CreateDefaultAudioOutputStream(audio_manager.get());
 295
 296   // Initial volume should be full volume (1.0).
 297   double volume = 0.0;
 298   aos->GetVolume(&volume);
 299   EXPECT_EQ(1.0, volume);
 300
 301   // Verify some valid volume settings.
 302   aos->SetVolume(0.0);
 303   aos->GetVolume(&volume);
 304   EXPECT_EQ(0.0, volume);
 305
 306   aos->SetVolume(0.5);
 307   aos->GetVolume(&volume);
 308   EXPECT_EQ(0.5, volume);
 309
 310   aos->SetVolume(1.0);
 311   aos->GetVolume(&volume);
 312   EXPECT_EQ(1.0, volume);
 313
 314   // Ensure that invalid volume setting have no effect.
 315   aos->SetVolume(1.5);
 316   aos->GetVolume(&volume);
 317   EXPECT_EQ(1.0, volume);
 318
 319   aos->SetVolume(-0.5);
 320   aos->GetVolume(&volume);
 321   EXPECT_EQ(1.0, volume);
 322
 323   aos->Close();
 324 }
 325
 326 // Test some additional calling sequences.
 327 TEST(WASAPIAudioOutputStreamTest, MiscCallingSequences) {
 328   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 329   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()));
 330
 331   AudioOutputStream* aos = CreateDefaultAudioOutputStream(audio_manager.get());
 332   WASAPIAudioOutputStream* waos = static_cast<WASAPIAudioOutputStream*>(aos);
 333
 334   // Open(), Open() is a valid calling sequence (second call does nothing).
 335   EXPECT_TRUE(aos->Open());
 336   EXPECT_TRUE(aos->Open());
 337
 338   MockAudioSourceCallback source;
 339
 340   // Start(), Start() is a valid calling sequence (second call does nothing).
 341   aos->Start(&source);
 342   EXPECT_TRUE(waos->started());
 343   aos->Start(&source);
 344   EXPECT_TRUE(waos->started());
 345
 346   // Stop(), Stop() is a valid calling sequence (second call does nothing).
 347   aos->Stop();
 348   EXPECT_FALSE(waos->started());
 349   aos->Stop();
 350   EXPECT_FALSE(waos->started());
 351
 352   // Start(), Stop(), Start(), Stop().
 353   aos->Start(&source);
 354   EXPECT_TRUE(waos->started());
 355   aos->Stop();
 356   EXPECT_FALSE(waos->started());
 357   aos->Start(&source);
 358   EXPECT_TRUE(waos->started());
 359   aos->Stop();
 360   EXPECT_FALSE(waos->started());
 361
 362   aos->Close();
 363 }
 364
 365 // Use preferred packet size and verify that rendering starts.
 366 TEST(WASAPIAudioOutputStreamTest, ValidPacketSize) {
 367   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 368   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()));
 369
 370   base::MessageLoopForUI loop;
 371   MockAudioSourceCallback source;
 372
 373   // Create default WASAPI output stream which plays out in stereo using
 374   // the shared mixing rate. The default buffer size is 10ms.
 375   AudioOutputStreamWrapper aosw(audio_manager.get());
 376   AudioOutputStream* aos = aosw.Create();
 377   EXPECT_TRUE(aos->Open());
 378
 379   // Derive the expected size in bytes of each packet.
 380   uint32 bytes_per_packet = aosw.channels() * aosw.samples_per_packet() *
 381       (aosw.bits_per_sample() / 8);
 382
 383   // Wait for the first callback and verify its parameters.
 384   EXPECT_CALL(source, OnMoreData(NotNull(), HasValidDelay(bytes_per_packet)))
 385       .WillOnce(DoAll(
 386           QuitLoop(loop.message_loop_proxy()),
 387           Return(aosw.samples_per_packet())));
 388
 389   aos->Start(&source);
 390   loop.PostDelayedTask(FROM_HERE, base::MessageLoop::QuitClosure(),
 391                        TestTimeouts::action_timeout());
 392   loop.Run();
 393   aos->Stop();
 394   aos->Close();
 395 }
 396
 397 // This test is intended for manual tests and should only be enabled
 398 // when it is required to play out data from a local PCM file.
 399 // By default, GTest will print out YOU HAVE 1 DISABLED TEST.
 400 // To include disabled tests in test execution, just invoke the test program
 401 // with --gtest_also_run_disabled_tests or set the GTEST_ALSO_RUN_DISABLED_TESTS
 402 // environment variable to a value greater than 0.
 403 // The test files are approximately 20 seconds long.
 404 TEST(WASAPIAudioOutputStreamTest, DISABLED_ReadFromStereoFile) {
 405   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 406   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()));
 407
 408   AudioOutputStreamWrapper aosw(audio_manager.get());
 409   AudioOutputStream* aos = aosw.Create();
 410   EXPECT_TRUE(aos->Open());
 411
 412   std::string file_name;
 413   if (aosw.sample_rate() == 48000) {
 414     file_name = kSpeechFile_16b_s_48k;
 415   } else if (aosw.sample_rate() == 44100) {
 416     file_name = kSpeechFile_16b_s_44k;
 417   } else if (aosw.sample_rate() == 96000) {
 418     // Use 48kHz file at 96kHz as well. Will sound like Donald Duck.
 419     file_name = kSpeechFile_16b_s_48k;
 420   } else {
 421     FAIL() << "This test supports 44.1, 48kHz and 96kHz only.";
 422     return;
 423   }
 424   ReadFromFileAudioSource file_source(file_name);
 425
 426   DVLOG(0) << "File name      : " << file_name.c_str();
 427   DVLOG(0) << "Sample rate    : " << aosw.sample_rate();
 428   DVLOG(0) << "Bits per sample: " << aosw.bits_per_sample();
 429   DVLOG(0) << "#channels      : " << aosw.channels();
 430   DVLOG(0) << "File size      : " << file_source.file_size();
 431   DVLOG(0) << "#file segments : " << kNumFileSegments;
 432   DVLOG(0) << ">> Listen to the stereo file while playing...";
 433
 434   for (int i = 0; i < kNumFileSegments; i++) {
 435     // Each segment will start with a short (~20ms) block of zeros, hence
 436     // some short glitches might be heard in this test if kNumFileSegments
 437     // is larger than one. The exact length of the silence period depends on
 438     // the selected sample rate.
 439     aos->Start(&file_source);
 440     base::PlatformThread::Sleep(
 441         base::TimeDelta::FromMilliseconds(kFileDurationMs / kNumFileSegments));
 442     aos->Stop();
 443   }
 444
 445   DVLOG(0) << ">> Stereo file playout has stopped.";
 446   aos->Close();
 447 }
 448
 449 // Verify that we can open the output stream in exclusive mode using a
 450 // certain set of audio parameters and a sample rate of 48kHz.
 451 // The expected outcomes of each setting in this test has been derived
 452 // manually using log outputs (--v=1).
 453 TEST(WASAPIAudioOutputStreamTest, ExclusiveModeBufferSizesAt48kHz) {
 454   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 455   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()) &&
 456                           ExclusiveModeIsEnabled());
 457
 458   AudioOutputStreamWrapper aosw(audio_manager.get());
 459
 460   // 10ms @ 48kHz shall work.
 461   // Note that, this is the same size as we can use for shared-mode streaming
 462   // but here the endpoint buffer delay is only 10ms instead of 20ms.
 463   AudioOutputStream* aos = aosw.Create(48000, 480);
 464   EXPECT_TRUE(aos->Open());
 465   aos->Close();
 466
 467   // 5ms @ 48kHz does not work due to misalignment.
 468   // This test will propose an aligned buffer size of 5.3333ms.
 469   // Note that we must call Close() even is Open() fails since Close() also
 470   // deletes the object and we want to create a new object in the next test.
 471   aos = aosw.Create(48000, 240);
 472   EXPECT_FALSE(aos->Open());
 473   aos->Close();
 474
 475   // 5.3333ms @ 48kHz should work (see test above).
 476   aos = aosw.Create(48000, 256);
 477   EXPECT_TRUE(aos->Open());
 478   aos->Close();
 479
 480   // 2.6667ms is smaller than the minimum supported size (=3ms).
 481   aos = aosw.Create(48000, 128);
 482   EXPECT_FALSE(aos->Open());
 483   aos->Close();
 484
 485   // 3ms does not correspond to an aligned buffer size.
 486   // This test will propose an aligned buffer size of 3.3333ms.
 487   aos = aosw.Create(48000, 144);
 488   EXPECT_FALSE(aos->Open());
 489   aos->Close();
 490
 491   // 3.3333ms @ 48kHz <=> smallest possible buffer size we can use.
 492   aos = aosw.Create(48000, 160);
 493   EXPECT_TRUE(aos->Open());
 494   aos->Close();
 495 }
 496
 497 // Verify that we can open the output stream in exclusive mode using a
 498 // certain set of audio parameters and a sample rate of 44.1kHz.
 499 // The expected outcomes of each setting in this test has been derived
 500 // manually using log outputs (--v=1).
 501 TEST(WASAPIAudioOutputStreamTest, ExclusiveModeBufferSizesAt44kHz) {
 502   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 503   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()) &&
 504                           ExclusiveModeIsEnabled());
 505
 506   AudioOutputStreamWrapper aosw(audio_manager.get());
 507
 508   // 10ms @ 44.1kHz does not work due to misalignment.
 509   // This test will propose an aligned buffer size of 10.1587ms.
 510   AudioOutputStream* aos = aosw.Create(44100, 441);
 511   EXPECT_FALSE(aos->Open());
 512   aos->Close();
 513
 514   // 10.1587ms @ 44.1kHz shall work (see test above).
 515   aos = aosw.Create(44100, 448);
 516   EXPECT_TRUE(aos->Open());
 517   aos->Close();
 518
 519   // 5.8050ms @ 44.1 should work.
 520   aos = aosw.Create(44100, 256);
 521   EXPECT_TRUE(aos->Open());
 522   aos->Close();
 523
 524   // 4.9887ms @ 44.1kHz does not work to misalignment.
 525   // This test will propose an aligned buffer size of 5.0794ms.
 526   // Note that we must call Close() even is Open() fails since Close() also
 527   // deletes the object and we want to create a new object in the next test.
 528   aos = aosw.Create(44100, 220);
 529   EXPECT_FALSE(aos->Open());
 530   aos->Close();
 531
 532   // 5.0794ms @ 44.1kHz shall work (see test above).
 533   aos = aosw.Create(44100, 224);
 534   EXPECT_TRUE(aos->Open());
 535   aos->Close();
 536
 537   // 2.9025ms is smaller than the minimum supported size (=3ms).
 538   aos = aosw.Create(44100, 132);
 539   EXPECT_FALSE(aos->Open());
 540   aos->Close();
 541
 542   // 3.01587ms is larger than the minimum size but is not aligned.
 543   // This test will propose an aligned buffer size of 3.6281ms.
 544   aos = aosw.Create(44100, 133);
 545   EXPECT_FALSE(aos->Open());
 546   aos->Close();
 547
 548   // 3.6281ms @ 44.1kHz <=> smallest possible buffer size we can use.
 549   aos = aosw.Create(44100, 160);
 550   EXPECT_TRUE(aos->Open());
 551   aos->Close();
 552 }
 553
 554 // Verify that we can open and start the output stream in exclusive mode at
 555 // the lowest possible delay at 48kHz.
 556 TEST(WASAPIAudioOutputStreamTest, ExclusiveModeMinBufferSizeAt48kHz) {
 557   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 558   ABORT_AUDIO_TEST_IF_NOT(HasCoreAudioAndOutputDevices(audio_manager.get()) &&
 559                           ExclusiveModeIsEnabled());
 560
 561   base::MessageLoopForUI loop;
 562   MockAudioSourceCallback source;
 563
 564   // Create exclusive-mode WASAPI output stream which plays out in stereo
 565   // using the minimum buffer size at 48kHz sample rate.
 566   AudioOutputStreamWrapper aosw(audio_manager.get());
 567   AudioOutputStream* aos = aosw.Create(48000, 160);
 568   EXPECT_TRUE(aos->Open());
 569
 570   // Derive the expected size in bytes of each packet.
 571   uint32 bytes_per_packet = aosw.channels() * aosw.samples_per_packet() *
 572       (aosw.bits_per_sample() / 8);
 573
 574  // Wait for the first callback and verify its parameters.
 575   EXPECT_CALL(source, OnMoreData(NotNull(), HasValidDelay(bytes_per_packet)))
 576       .WillOnce(DoAll(
 577           QuitLoop(loop.message_loop_proxy()),
 578           Return(aosw.samples_per_packet())))
 579       .WillRepeatedly(Return(aosw.samples_per_packet()));
 580
 581   aos->Start(&source);
 582   loop.PostDelayedTask(FROM_HERE, base::MessageLoop::QuitClosure(),
 583                        TestTimeouts::action_timeout());
 584   loop.Run();
 585   aos->Stop();
 586   aos->Close();
 587 }
 588
 589 // Verify that we can open and start the output stream in exclusive mode at
 590 // the lowest possible delay at 44.1kHz.
 591 TEST(WASAPIAudioOutputStreamTest, ExclusiveModeMinBufferSizeAt44kHz) {
 592   ABORT_AUDIO_TEST_IF_NOT(ExclusiveModeIsEnabled());
 593   scoped_ptr<AudioManager> audio_manager(AudioManager::CreateForTesting());
 594
 595   base::MessageLoopForUI loop;
 596   MockAudioSourceCallback source;
 597
 598   // Create exclusive-mode WASAPI output stream which plays out in stereo
 599   // using the minimum buffer size at 44.1kHz sample rate.
 600   AudioOutputStreamWrapper aosw(audio_manager.get());
 601   AudioOutputStream* aos = aosw.Create(44100, 160);
 602   EXPECT_TRUE(aos->Open());
 603
 604   // Derive the expected size in bytes of each packet.
 605   uint32 bytes_per_packet = aosw.channels() * aosw.samples_per_packet() *
 606       (aosw.bits_per_sample() / 8);
 607
 608   // Wait for the first callback and verify its parameters.
 609   EXPECT_CALL(source, OnMoreData(NotNull(), HasValidDelay(bytes_per_packet)))
 610     .WillOnce(DoAll(
 611         QuitLoop(loop.message_loop_proxy()),
 612         Return(aosw.samples_per_packet())))
 613     .WillRepeatedly(Return(aosw.samples_per_packet()));
 614
 615   aos->Start(&source);
 616   loop.PostDelayedTask(FROM_HERE, base::MessageLoop::QuitClosure(),
 617                         TestTimeouts::action_timeout());
 618   loop.Run();
 619   aos->Stop();
 620   aos->Close();
 621 }
 622
 623 }  // namespace media