webrtc/modules/audio_mixer/test/audio_mixer_unittest.cc - src - Git at Google

 /*
  *  Copyright (c) 2016 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 <memory>
 #include <utility>

 #include "testing/gmock/include/gmock/gmock.h"
 #include "webrtc/base/bind.h"
 #include "webrtc/base/thread.h"
 #include "webrtc/modules/audio_mixer/audio_mixer_defines.h"
 #include "webrtc/modules/audio_mixer/audio_mixer.h"

 using testing::_;
 using testing::Exactly;
 using testing::Invoke;
 using testing::Return;

 namespace webrtc {

 namespace {

 constexpr int kDefaultSampleRateHz = 48000;
 constexpr int kId = 1;

 // Utility function that resets the frame member variables with
 // sensible defaults.
 void ResetFrame(AudioFrame* frame) {
   frame->id_ = kId;
   frame->sample_rate_hz_ = kDefaultSampleRateHz;
   frame->num_channels_ = 1;

   // Frame duration 10ms.
   frame->samples_per_channel_ = kDefaultSampleRateHz / 100;
   frame->vad_activity_ = AudioFrame::kVadActive;
   frame->speech_type_ = AudioFrame::kNormalSpeech;
 }

 AudioFrame frame_for_mixing;

 }  // namespace

 class MockMixerAudioSource : public MixerAudioSource {
  public:
   MockMixerAudioSource()
       : fake_audio_frame_info_(MixerAudioSource::AudioFrameInfo::kNormal) {
     ON_CALL(*this, GetAudioFrameWithMuted(_, _))
         .WillByDefault(
             Invoke(this, &MockMixerAudioSource::FakeAudioFrameWithMuted));
   }

   MOCK_METHOD2(GetAudioFrameWithMuted,
                AudioFrameWithMuted(const int32_t id, int sample_rate_hz));

   AudioFrame* fake_frame() { return &fake_frame_; }
   AudioFrameInfo fake_info() { return fake_audio_frame_info_; }
   void set_fake_info(const AudioFrameInfo audio_frame_info) {
     fake_audio_frame_info_ = audio_frame_info;
   }

  private:
   AudioFrame fake_frame_, fake_output_frame_;
   AudioFrameInfo fake_audio_frame_info_;
   AudioFrameWithMuted FakeAudioFrameWithMuted(const int32_t id,
                                               int sample_rate_hz) {
     fake_output_frame_.CopyFrom(fake_frame_);
     return {
         &fake_output_frame_,  // audio_frame_pointer
         fake_info(),          // audio_frame_info
     };
   }
 };

 // Creates participants from |frames| and |frame_info| and adds them
 // to the mixer. Compares mixed status with |expected_status|
 void MixAndCompare(
     const std::vector<AudioFrame>& frames,
     const std::vector<MixerAudioSource::AudioFrameInfo>& frame_info,
     const std::vector<bool>& expected_status) {
   int num_audio_sources = frames.size();
   RTC_DCHECK(frames.size() == frame_info.size());
   RTC_DCHECK(frame_info.size() == expected_status.size());

   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));
   std::vector<MockMixerAudioSource> participants(num_audio_sources);

   for (int i = 0; i < num_audio_sources; i++) {
     participants[i].fake_frame()->CopyFrom(frames[i]);
     participants[i].set_fake_info(frame_info[i]);
   }

   for (int i = 0; i < num_audio_sources; i++) {
     EXPECT_EQ(0, mixer->SetMixabilityStatus(&participants[i], true));
     EXPECT_CALL(participants[i],
                 GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
         .Times(Exactly(1));
   }

   mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);

   for (int i = 0; i < num_audio_sources; i++) {
     EXPECT_EQ(expected_status[i], participants[i].IsMixed())
         << "Mixed status of AudioSource #" << i << " wrong.";
   }
 }

 TEST(AudioMixer, AnonymousAndNamed) {
   // Should not matter even if partipants are more than
   // kMaximumAmountOfMixedAudioSources.
   constexpr int kNamed = AudioMixer::kMaximumAmountOfMixedAudioSources + 1;
   constexpr int kAnonymous = AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

   MockMixerAudioSource named[kNamed];
   MockMixerAudioSource anonymous[kAnonymous];

   for (int i = 0; i < kNamed; ++i) {
     EXPECT_EQ(0, mixer->SetMixabilityStatus(&named[i], true));
     EXPECT_TRUE(mixer->MixabilityStatus(named[i]));
   }

   for (int i = 0; i < kAnonymous; ++i) {
     // AudioSource must be registered before turning it into anonymous.
     EXPECT_EQ(-1, mixer->SetAnonymousMixabilityStatus(&anonymous[i], true));
     EXPECT_EQ(0, mixer->SetMixabilityStatus(&anonymous[i], true));
     EXPECT_TRUE(mixer->MixabilityStatus(anonymous[i]));
     EXPECT_FALSE(mixer->AnonymousMixabilityStatus(anonymous[i]));

     EXPECT_EQ(0, mixer->SetAnonymousMixabilityStatus(&anonymous[i], true));
     EXPECT_TRUE(mixer->AnonymousMixabilityStatus(anonymous[i]));

     // Anonymous participants do not show status by MixabilityStatus.
     EXPECT_FALSE(mixer->MixabilityStatus(anonymous[i]));
   }

   for (int i = 0; i < kNamed; ++i) {
     EXPECT_EQ(0, mixer->SetMixabilityStatus(&named[i], false));
     EXPECT_FALSE(mixer->MixabilityStatus(named[i]));
   }

   for (int i = 0; i < kAnonymous - 1; i++) {
     EXPECT_EQ(0, mixer->SetAnonymousMixabilityStatus(&anonymous[i], false));
     EXPECT_FALSE(mixer->AnonymousMixabilityStatus(anonymous[i]));

     // SetAnonymousMixabilityStatus(anonymous, false) moves anonymous to the
     // named group.
     EXPECT_TRUE(mixer->MixabilityStatus(anonymous[i]));
   }

   // SetMixabilityStatus(anonymous, false) will remove anonymous from both
   // anonymous and named groups.
   EXPECT_EQ(0, mixer->SetMixabilityStatus(&anonymous[kAnonymous - 1], false));
   EXPECT_FALSE(mixer->AnonymousMixabilityStatus(anonymous[kAnonymous - 1]));
   EXPECT_FALSE(mixer->MixabilityStatus(anonymous[kAnonymous - 1]));
 }

 TEST(AudioMixer, LargestEnergyVadActiveMixed) {
   constexpr int kAudioSources =
       AudioMixer::kMaximumAmountOfMixedAudioSources + 3;

   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

   MockMixerAudioSource participants[kAudioSources];

   for (int i = 0; i < kAudioSources; ++i) {
     ResetFrame(participants[i].fake_frame());

     // We set the 80-th sample value since the first 80 samples may be
     // modified by a ramped-in window.
     participants[i].fake_frame()->data_[80] = i;

     EXPECT_EQ(0, mixer->SetMixabilityStatus(&participants[i], true));
     EXPECT_CALL(participants[i], GetAudioFrameWithMuted(_, _))
         .Times(Exactly(1));
   }

   // Last participant gives audio frame with passive VAD, although it has the
   // largest energy.
   participants[kAudioSources - 1].fake_frame()->vad_activity_ =
       AudioFrame::kVadPassive;

   AudioFrame audio_frame;
   mixer->Mix(kDefaultSampleRateHz,
              1,  // number of channels
              &audio_frame);

   for (int i = 0; i < kAudioSources; ++i) {
     bool is_mixed = participants[i].IsMixed();
     if (i == kAudioSources - 1 ||
         i < kAudioSources - 1 - AudioMixer::kMaximumAmountOfMixedAudioSources) {
       EXPECT_FALSE(is_mixed) << "Mixing status of AudioSource #" << i
                              << " wrong.";
     } else {
       EXPECT_TRUE(is_mixed) << "Mixing status of AudioSource #" << i
                             << " wrong.";
     }
   }
 }

 TEST(AudioMixer, FrameNotModifiedForSingleParticipant) {
   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

   MockMixerAudioSource participant;

   ResetFrame(participant.fake_frame());
   const int n_samples = participant.fake_frame()->samples_per_channel_;

   // Modify the frame so that it's not zero.
   for (int j = 0; j < n_samples; j++) {
     participant.fake_frame()->data_[j] = j;
   }

   EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
   EXPECT_CALL(participant, GetAudioFrameWithMuted(_, _)).Times(Exactly(2));

   AudioFrame audio_frame;
   // Two mix iteration to compare after the ramp-up step.
   for (int i = 0; i < 2; i++) {
     mixer->Mix(kDefaultSampleRateHz,
                1,  // number of channels
                &audio_frame);
   }

   EXPECT_EQ(
       0, memcmp(participant.fake_frame()->data_, audio_frame.data_, n_samples));
 }

 TEST(AudioMixer, FrameNotModifiedForSingleAnonymousParticipant) {
   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

   MockMixerAudioSource participant;

   ResetFrame(participant.fake_frame());
   const int n_samples = participant.fake_frame()->samples_per_channel_;

   // Modify the frame so that it's not zero.
   for (int j = 0; j < n_samples; j++) {
     participant.fake_frame()->data_[j] = j;
   }

   EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
   EXPECT_EQ(0, mixer->SetAnonymousMixabilityStatus(&participant, true));
   EXPECT_CALL(participant, GetAudioFrameWithMuted(_, _)).Times(Exactly(2));

   AudioFrame audio_frame;
   // Two mix iteration to compare after the ramp-up step.
   for (int i = 0; i < 2; i++) {
     mixer->Mix(kDefaultSampleRateHz,
                1,  // number of channels
                &audio_frame);
   }

   EXPECT_EQ(
       0, memcmp(participant.fake_frame()->data_, audio_frame.data_, n_samples));
 }

 TEST(AudioMixer, ParticipantSampleRate) {
   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

   MockMixerAudioSource participant;
   ResetFrame(participant.fake_frame());

   EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
   for (auto frequency : {8000, 16000, 32000, 48000}) {
     EXPECT_CALL(participant, GetAudioFrameWithMuted(_, frequency))
         .Times(Exactly(1));
     participant.fake_frame()->sample_rate_hz_ = frequency;
     participant.fake_frame()->samples_per_channel_ = frequency / 100;
     mixer->Mix(frequency, 1, &frame_for_mixing);
     EXPECT_EQ(frequency, frame_for_mixing.sample_rate_hz_);
   }
 }

 TEST(AudioMixer, ParticipantNumberOfChannels) {
   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

   MockMixerAudioSource participant;
   ResetFrame(participant.fake_frame());

   EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
   for (size_t number_of_channels : {1, 2}) {
     EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
         .Times(Exactly(1));
     mixer->Mix(kDefaultSampleRateHz, number_of_channels, &frame_for_mixing);
     EXPECT_EQ(number_of_channels, frame_for_mixing.num_channels_);
   }
 }

 // Test that the volume is reported as zero when the mixer input
 // comprises only zero values.
 TEST(AudioMixer, LevelIsZeroWhenMixingZeroes) {
   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

   MockMixerAudioSource participant;
   ResetFrame(participant.fake_frame());

   EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
   for (int i = 0; i < 11; i++) {
     EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
         .Times(Exactly(1));
     mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);
   }

   EXPECT_EQ(0, mixer->GetOutputAudioLevel());
   EXPECT_EQ(0, mixer->GetOutputAudioLevelFullRange());
 }

 // Test that the reported volume is maximal when the mixer
 // input comprises frames with maximal values.
 TEST(AudioMixer, LevelIsMaximalWhenMixingMaximalValues) {
   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

   MockMixerAudioSource participant;
   ResetFrame(participant.fake_frame());

   // Fill participant frame data with maximal sound.
   std::fill(participant.fake_frame()->data_,
             participant.fake_frame()->data_ + kDefaultSampleRateHz / 100,
             std::numeric_limits<int16_t>::max());

   EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));

   // We do >10 iterations, because the audio level indicator only
   // updates once every 10 calls.
   for (int i = 0; i < 11; i++) {
     EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
         .Times(Exactly(1));
     mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);
   }

   // 9 is the highest possible audio level
   EXPECT_EQ(9, mixer->GetOutputAudioLevel());

   // 0x7fff = 32767 is the highest full range audio level.
   EXPECT_EQ(std::numeric_limits<int16_t>::max(),
             mixer->GetOutputAudioLevelFullRange());
 }

 // Maximal amount of participants are mixed one iteration, then
 // another participant with higher energy is added.
 TEST(AudioMixer, RampedOutSourcesShouldNotBeMarkedMixed) {
   constexpr int kAudioSources =
       AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));
   MockMixerAudioSource participants[kAudioSources];

   for (int i = 0; i < kAudioSources; i++) {
     ResetFrame(participants[i].fake_frame());
     // Set the participant audio energy to increase with the index
     // |i|.
     participants[i].fake_frame()->data_[0] = 100 * i;
   }

   // Add all participants but the loudest for mixing.
   for (int i = 0; i < kAudioSources - 1; i++) {
     EXPECT_EQ(0, mixer->SetMixabilityStatus(&participants[i], true));
     EXPECT_CALL(participants[i],
                 GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
         .Times(Exactly(1));
   }

   // First mixer iteration
   mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);

   // All participants but the loudest should have been mixed.
   for (int i = 0; i < kAudioSources - 1; i++) {
     EXPECT_TRUE(participants[i].IsMixed()) << "Mixed status of AudioSource #"
                                            << i << " wrong.";
   }

   // Add new participant with higher energy.
   EXPECT_EQ(0,
             mixer->SetMixabilityStatus(&participants[kAudioSources - 1], true));
   for (int i = 0; i < kAudioSources; i++) {
     EXPECT_CALL(participants[i],
                 GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
         .Times(Exactly(1));
   }

   mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);

   // The most quiet participant should not have been mixed.
   EXPECT_FALSE(participants[0].IsMixed())
       << "Mixed status of AudioSource #0 wrong.";

   // The loudest participants should have been mixed.
   for (int i = 1; i < kAudioSources; i++) {
     EXPECT_EQ(true, participants[i].IsMixed())
         << "Mixed status of AudioSource #" << i << " wrong.";
   }
 }

 // This test checks that the initialization and participant addition
 // can be done on a different thread.
 TEST(AudioMixer, ConstructFromOtherThread) {
   std::unique_ptr<rtc::Thread> init_thread = rtc::Thread::Create();
   std::unique_ptr<rtc::Thread> participant_thread = rtc::Thread::Create();
   init_thread->Start();
   std::unique_ptr<AudioMixer> mixer(
       init_thread->Invoke<std::unique_ptr<AudioMixer>>(
           RTC_FROM_HERE, std::bind(&AudioMixer::Create, kId)));
   MockMixerAudioSource participant;

   ResetFrame(participant.fake_frame());

   participant_thread->Start();
   EXPECT_EQ(0, participant_thread->Invoke<int>(
                    RTC_FROM_HERE, rtc::Bind(&AudioMixer::SetMixabilityStatus,
                                             mixer.get(), &participant, true)));

   EXPECT_EQ(
       0, participant_thread->Invoke<int>(
              RTC_FROM_HERE, rtc::Bind(&AudioMixer::SetAnonymousMixabilityStatus,
                                       mixer.get(), &participant, true)));

   EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
       .Times(Exactly(1));

   // Do one mixer iteration
   mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);
 }

 TEST(AudioMixer, MutedShouldMixAfterUnmuted) {
   constexpr int kAudioSources =
       AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

   std::vector<AudioFrame> frames(kAudioSources);
   for (auto& frame : frames) {
     ResetFrame(&frame);
   }

   std::vector<MixerAudioSource::AudioFrameInfo> frame_info(
       kAudioSources, MixerAudioSource::AudioFrameInfo::kNormal);
   frame_info[0] = MixerAudioSource::AudioFrameInfo::kMuted;
   std::vector<bool> expected_status(kAudioSources, true);
   expected_status[0] = false;

   MixAndCompare(frames, frame_info, expected_status);
 }

 TEST(AudioMixer, PassiveShouldMixAfterNormal) {
   constexpr int kAudioSources =
       AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

   std::vector<AudioFrame> frames(kAudioSources);
   for (auto& frame : frames) {
     ResetFrame(&frame);
   }

   std::vector<MixerAudioSource::AudioFrameInfo> frame_info(
       kAudioSources, MixerAudioSource::AudioFrameInfo::kNormal);
   frames[0].vad_activity_ = AudioFrame::kVadPassive;
   std::vector<bool> expected_status(kAudioSources, true);
   expected_status[0] = false;

   MixAndCompare(frames, frame_info, expected_status);
 }

 TEST(AudioMixer, ActiveShouldMixBeforeLoud) {
   constexpr int kAudioSources =
       AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

   std::vector<AudioFrame> frames(kAudioSources);
   for (auto& frame : frames) {
     ResetFrame(&frame);
   }

   std::vector<MixerAudioSource::AudioFrameInfo> frame_info(
       kAudioSources, MixerAudioSource::AudioFrameInfo::kNormal);
   frames[0].vad_activity_ = AudioFrame::kVadPassive;
   std::fill(frames[0].data_, frames[0].data_ + kDefaultSampleRateHz / 100,
             std::numeric_limits<int16_t>::max());
   std::vector<bool> expected_status(kAudioSources, true);
   expected_status[0] = false;

   MixAndCompare(frames, frame_info, expected_status);
 }

 TEST(AudioMixer, UnmutedShouldMixBeforeLoud) {
   constexpr int kAudioSources =
       AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

   std::vector<AudioFrame> frames(kAudioSources);
   for (auto& frame : frames) {
     ResetFrame(&frame);
   }

   std::vector<MixerAudioSource::AudioFrameInfo> frame_info(
       kAudioSources, MixerAudioSource::AudioFrameInfo::kNormal);
   frame_info[0] = MixerAudioSource::AudioFrameInfo::kMuted;
   std::fill(frames[0].data_, frames[0].data_ + kDefaultSampleRateHz / 100,
             std::numeric_limits<int16_t>::max());
   std::vector<bool> expected_status(kAudioSources, true);
   expected_status[0] = false;

   MixAndCompare(frames, frame_info, expected_status);
 }
 }  // namespace webrtc
	/*
	* Copyright (c) 2016 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 <memory>
	#include <utility>

	#include "testing/gmock/include/gmock/gmock.h"
	#include "webrtc/base/bind.h"
	#include "webrtc/base/thread.h"
	#include "webrtc/modules/audio_mixer/audio_mixer_defines.h"
	#include "webrtc/modules/audio_mixer/audio_mixer.h"

	using testing::_;
	using testing::Exactly;
	using testing::Invoke;
	using testing::Return;

	namespace webrtc {

	namespace {

	constexpr int kDefaultSampleRateHz = 48000;
	constexpr int kId = 1;

	// Utility function that resets the frame member variables with
	// sensible defaults.
	void ResetFrame(AudioFrame* frame) {
	frame->id_ = kId;
	frame->sample_rate_hz_ = kDefaultSampleRateHz;
	frame->num_channels_ = 1;

	// Frame duration 10ms.
	frame->samples_per_channel_ = kDefaultSampleRateHz / 100;
	frame->vad_activity_ = AudioFrame::kVadActive;
	frame->speech_type_ = AudioFrame::kNormalSpeech;
	}

	AudioFrame frame_for_mixing;

	} // namespace

	class MockMixerAudioSource : public MixerAudioSource {
	public:
	MockMixerAudioSource()
	: fake_audio_frame_info_(MixerAudioSource::AudioFrameInfo::kNormal) {
	ON_CALL(*this, GetAudioFrameWithMuted(_, _))
	.WillByDefault(
	Invoke(this, &MockMixerAudioSource::FakeAudioFrameWithMuted));
	}

	MOCK_METHOD2(GetAudioFrameWithMuted,
	AudioFrameWithMuted(const int32_t id, int sample_rate_hz));

	AudioFrame* fake_frame() { return &fake_frame_; }
	AudioFrameInfo fake_info() { return fake_audio_frame_info_; }
	void set_fake_info(const AudioFrameInfo audio_frame_info) {
	fake_audio_frame_info_ = audio_frame_info;
	}

	private:
	AudioFrame fake_frame_, fake_output_frame_;
	AudioFrameInfo fake_audio_frame_info_;
	AudioFrameWithMuted FakeAudioFrameWithMuted(const int32_t id,
	int sample_rate_hz) {
	fake_output_frame_.CopyFrom(fake_frame_);
	return {
	&fake_output_frame_, // audio_frame_pointer
	fake_info(), // audio_frame_info
	};
	}
	};

	// Creates participants from \|frames\| and \|frame_info\| and adds them
	// to the mixer. Compares mixed status with \|expected_status\|
	void MixAndCompare(
	const std::vector<AudioFrame>& frames,
	const std::vector<MixerAudioSource::AudioFrameInfo>& frame_info,
	const std::vector<bool>& expected_status) {
	int num_audio_sources = frames.size();
	RTC_DCHECK(frames.size() == frame_info.size());
	RTC_DCHECK(frame_info.size() == expected_status.size());

	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));
	std::vector<MockMixerAudioSource> participants(num_audio_sources);

	for (int i = 0; i < num_audio_sources; i++) {
	participants[i].fake_frame()->CopyFrom(frames[i]);
	participants[i].set_fake_info(frame_info[i]);
	}

	for (int i = 0; i < num_audio_sources; i++) {
	EXPECT_EQ(0, mixer->SetMixabilityStatus(&participants[i], true));
	EXPECT_CALL(participants[i],
	GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
	.Times(Exactly(1));
	}

	mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);

	for (int i = 0; i < num_audio_sources; i++) {
	EXPECT_EQ(expected_status[i], participants[i].IsMixed())
	<< "Mixed status of AudioSource #" << i << " wrong.";
	}
	}

	TEST(AudioMixer, AnonymousAndNamed) {
	// Should not matter even if partipants are more than
	// kMaximumAmountOfMixedAudioSources.
	constexpr int kNamed = AudioMixer::kMaximumAmountOfMixedAudioSources + 1;
	constexpr int kAnonymous = AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

	MockMixerAudioSource named[kNamed];
	MockMixerAudioSource anonymous[kAnonymous];

	for (int i = 0; i < kNamed; ++i) {
	EXPECT_EQ(0, mixer->SetMixabilityStatus(&named[i], true));
	EXPECT_TRUE(mixer->MixabilityStatus(named[i]));
	}

	for (int i = 0; i < kAnonymous; ++i) {
	// AudioSource must be registered before turning it into anonymous.
	EXPECT_EQ(-1, mixer->SetAnonymousMixabilityStatus(&anonymous[i], true));
	EXPECT_EQ(0, mixer->SetMixabilityStatus(&anonymous[i], true));
	EXPECT_TRUE(mixer->MixabilityStatus(anonymous[i]));
	EXPECT_FALSE(mixer->AnonymousMixabilityStatus(anonymous[i]));

	EXPECT_EQ(0, mixer->SetAnonymousMixabilityStatus(&anonymous[i], true));
	EXPECT_TRUE(mixer->AnonymousMixabilityStatus(anonymous[i]));

	// Anonymous participants do not show status by MixabilityStatus.
	EXPECT_FALSE(mixer->MixabilityStatus(anonymous[i]));
	}

	for (int i = 0; i < kNamed; ++i) {
	EXPECT_EQ(0, mixer->SetMixabilityStatus(&named[i], false));
	EXPECT_FALSE(mixer->MixabilityStatus(named[i]));
	}

	for (int i = 0; i < kAnonymous - 1; i++) {
	EXPECT_EQ(0, mixer->SetAnonymousMixabilityStatus(&anonymous[i], false));
	EXPECT_FALSE(mixer->AnonymousMixabilityStatus(anonymous[i]));

	// SetAnonymousMixabilityStatus(anonymous, false) moves anonymous to the
	// named group.
	EXPECT_TRUE(mixer->MixabilityStatus(anonymous[i]));
	}

	// SetMixabilityStatus(anonymous, false) will remove anonymous from both
	// anonymous and named groups.
	EXPECT_EQ(0, mixer->SetMixabilityStatus(&anonymous[kAnonymous - 1], false));
	EXPECT_FALSE(mixer->AnonymousMixabilityStatus(anonymous[kAnonymous - 1]));
	EXPECT_FALSE(mixer->MixabilityStatus(anonymous[kAnonymous - 1]));
	}

	TEST(AudioMixer, LargestEnergyVadActiveMixed) {
	constexpr int kAudioSources =
	AudioMixer::kMaximumAmountOfMixedAudioSources + 3;

	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

	MockMixerAudioSource participants[kAudioSources];

	for (int i = 0; i < kAudioSources; ++i) {
	ResetFrame(participants[i].fake_frame());

	// We set the 80-th sample value since the first 80 samples may be
	// modified by a ramped-in window.
	participants[i].fake_frame()->data_[80] = i;

	EXPECT_EQ(0, mixer->SetMixabilityStatus(&participants[i], true));
	EXPECT_CALL(participants[i], GetAudioFrameWithMuted(_, _))
	.Times(Exactly(1));
	}

	// Last participant gives audio frame with passive VAD, although it has the
	// largest energy.
	participants[kAudioSources - 1].fake_frame()->vad_activity_ =
	AudioFrame::kVadPassive;

	AudioFrame audio_frame;
	mixer->Mix(kDefaultSampleRateHz,
	1, // number of channels
	&audio_frame);

	for (int i = 0; i < kAudioSources; ++i) {
	bool is_mixed = participants[i].IsMixed();
	if (i == kAudioSources - 1 \|\|
	i < kAudioSources - 1 - AudioMixer::kMaximumAmountOfMixedAudioSources) {
	EXPECT_FALSE(is_mixed) << "Mixing status of AudioSource #" << i
	<< " wrong.";
	} else {
	EXPECT_TRUE(is_mixed) << "Mixing status of AudioSource #" << i
	<< " wrong.";
	}
	}
	}

	TEST(AudioMixer, FrameNotModifiedForSingleParticipant) {
	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

	MockMixerAudioSource participant;

	ResetFrame(participant.fake_frame());
	const int n_samples = participant.fake_frame()->samples_per_channel_;

	// Modify the frame so that it's not zero.
	for (int j = 0; j < n_samples; j++) {
	participant.fake_frame()->data_[j] = j;
	}

	EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
	EXPECT_CALL(participant, GetAudioFrameWithMuted(_, _)).Times(Exactly(2));

	AudioFrame audio_frame;
	// Two mix iteration to compare after the ramp-up step.
	for (int i = 0; i < 2; i++) {
	mixer->Mix(kDefaultSampleRateHz,
	1, // number of channels
	&audio_frame);
	}

	EXPECT_EQ(
	0, memcmp(participant.fake_frame()->data_, audio_frame.data_, n_samples));
	}

	TEST(AudioMixer, FrameNotModifiedForSingleAnonymousParticipant) {
	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

	MockMixerAudioSource participant;

	ResetFrame(participant.fake_frame());
	const int n_samples = participant.fake_frame()->samples_per_channel_;

	// Modify the frame so that it's not zero.
	for (int j = 0; j < n_samples; j++) {
	participant.fake_frame()->data_[j] = j;
	}

	EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
	EXPECT_EQ(0, mixer->SetAnonymousMixabilityStatus(&participant, true));
	EXPECT_CALL(participant, GetAudioFrameWithMuted(_, _)).Times(Exactly(2));

	AudioFrame audio_frame;
	// Two mix iteration to compare after the ramp-up step.
	for (int i = 0; i < 2; i++) {
	mixer->Mix(kDefaultSampleRateHz,
	1, // number of channels
	&audio_frame);
	}

	EXPECT_EQ(
	0, memcmp(participant.fake_frame()->data_, audio_frame.data_, n_samples));
	}

	TEST(AudioMixer, ParticipantSampleRate) {
	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

	MockMixerAudioSource participant;
	ResetFrame(participant.fake_frame());

	EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
	for (auto frequency : {8000, 16000, 32000, 48000}) {
	EXPECT_CALL(participant, GetAudioFrameWithMuted(_, frequency))
	.Times(Exactly(1));
	participant.fake_frame()->sample_rate_hz_ = frequency;
	participant.fake_frame()->samples_per_channel_ = frequency / 100;
	mixer->Mix(frequency, 1, &frame_for_mixing);
	EXPECT_EQ(frequency, frame_for_mixing.sample_rate_hz_);
	}
	}

	TEST(AudioMixer, ParticipantNumberOfChannels) {
	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

	MockMixerAudioSource participant;
	ResetFrame(participant.fake_frame());

	EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
	for (size_t number_of_channels : {1, 2}) {
	EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
	.Times(Exactly(1));
	mixer->Mix(kDefaultSampleRateHz, number_of_channels, &frame_for_mixing);
	EXPECT_EQ(number_of_channels, frame_for_mixing.num_channels_);
	}
	}

	// Test that the volume is reported as zero when the mixer input
	// comprises only zero values.
	TEST(AudioMixer, LevelIsZeroWhenMixingZeroes) {
	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

	MockMixerAudioSource participant;
	ResetFrame(participant.fake_frame());

	EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
	for (int i = 0; i < 11; i++) {
	EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
	.Times(Exactly(1));
	mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);
	}

	EXPECT_EQ(0, mixer->GetOutputAudioLevel());
	EXPECT_EQ(0, mixer->GetOutputAudioLevelFullRange());
	}

	// Test that the reported volume is maximal when the mixer
	// input comprises frames with maximal values.
	TEST(AudioMixer, LevelIsMaximalWhenMixingMaximalValues) {
	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));

	MockMixerAudioSource participant;
	ResetFrame(participant.fake_frame());

	// Fill participant frame data with maximal sound.
	std::fill(participant.fake_frame()->data_,
	participant.fake_frame()->data_ + kDefaultSampleRateHz / 100,
	std::numeric_limits<int16_t>::max());

	EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));

	// We do >10 iterations, because the audio level indicator only
	// updates once every 10 calls.
	for (int i = 0; i < 11; i++) {
	EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
	.Times(Exactly(1));
	mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);
	}

	// 9 is the highest possible audio level
	EXPECT_EQ(9, mixer->GetOutputAudioLevel());

	// 0x7fff = 32767 is the highest full range audio level.
	EXPECT_EQ(std::numeric_limits<int16_t>::max(),
	mixer->GetOutputAudioLevelFullRange());
	}

	// Maximal amount of participants are mixed one iteration, then
	// another participant with higher energy is added.
	TEST(AudioMixer, RampedOutSourcesShouldNotBeMarkedMixed) {
	constexpr int kAudioSources =
	AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

	const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));
	MockMixerAudioSource participants[kAudioSources];

	for (int i = 0; i < kAudioSources; i++) {
	ResetFrame(participants[i].fake_frame());
	// Set the participant audio energy to increase with the index
	// \|i\|.
	participants[i].fake_frame()->data_[0] = 100 * i;
	}

	// Add all participants but the loudest for mixing.
	for (int i = 0; i < kAudioSources - 1; i++) {
	EXPECT_EQ(0, mixer->SetMixabilityStatus(&participants[i], true));
	EXPECT_CALL(participants[i],
	GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
	.Times(Exactly(1));
	}

	// First mixer iteration
	mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);

	// All participants but the loudest should have been mixed.
	for (int i = 0; i < kAudioSources - 1; i++) {
	EXPECT_TRUE(participants[i].IsMixed()) << "Mixed status of AudioSource #"
	<< i << " wrong.";
	}

	// Add new participant with higher energy.
	EXPECT_EQ(0,
	mixer->SetMixabilityStatus(&participants[kAudioSources - 1], true));
	for (int i = 0; i < kAudioSources; i++) {
	EXPECT_CALL(participants[i],
	GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
	.Times(Exactly(1));
	}

	mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);

	// The most quiet participant should not have been mixed.
	EXPECT_FALSE(participants[0].IsMixed())
	<< "Mixed status of AudioSource #0 wrong.";

	// The loudest participants should have been mixed.
	for (int i = 1; i < kAudioSources; i++) {
	EXPECT_EQ(true, participants[i].IsMixed())
	<< "Mixed status of AudioSource #" << i << " wrong.";
	}
	}

	// This test checks that the initialization and participant addition
	// can be done on a different thread.
	TEST(AudioMixer, ConstructFromOtherThread) {
	std::unique_ptr<rtc::Thread> init_thread = rtc::Thread::Create();
	std::unique_ptr<rtc::Thread> participant_thread = rtc::Thread::Create();
	init_thread->Start();
	std::unique_ptr<AudioMixer> mixer(
	init_thread->Invoke<std::unique_ptr<AudioMixer>>(
	RTC_FROM_HERE, std::bind(&AudioMixer::Create, kId)));
	MockMixerAudioSource participant;

	ResetFrame(participant.fake_frame());

	participant_thread->Start();
	EXPECT_EQ(0, participant_thread->Invoke<int>(
	RTC_FROM_HERE, rtc::Bind(&AudioMixer::SetMixabilityStatus,
	mixer.get(), &participant, true)));

	EXPECT_EQ(
	0, participant_thread->Invoke<int>(
	RTC_FROM_HERE, rtc::Bind(&AudioMixer::SetAnonymousMixabilityStatus,
	mixer.get(), &participant, true)));

	EXPECT_CALL(participant, GetAudioFrameWithMuted(_, kDefaultSampleRateHz))
	.Times(Exactly(1));

	// Do one mixer iteration
	mixer->Mix(kDefaultSampleRateHz, 1, &frame_for_mixing);
	}

	TEST(AudioMixer, MutedShouldMixAfterUnmuted) {
	constexpr int kAudioSources =
	AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

	std::vector<AudioFrame> frames(kAudioSources);
	for (auto& frame : frames) {
	ResetFrame(&frame);
	}

	std::vector<MixerAudioSource::AudioFrameInfo> frame_info(
	kAudioSources, MixerAudioSource::AudioFrameInfo::kNormal);
	frame_info[0] = MixerAudioSource::AudioFrameInfo::kMuted;
	std::vector<bool> expected_status(kAudioSources, true);
	expected_status[0] = false;

	MixAndCompare(frames, frame_info, expected_status);
	}

	TEST(AudioMixer, PassiveShouldMixAfterNormal) {
	constexpr int kAudioSources =
	AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

	std::vector<AudioFrame> frames(kAudioSources);
	for (auto& frame : frames) {
	ResetFrame(&frame);
	}

	std::vector<MixerAudioSource::AudioFrameInfo> frame_info(
	kAudioSources, MixerAudioSource::AudioFrameInfo::kNormal);
	frames[0].vad_activity_ = AudioFrame::kVadPassive;
	std::vector<bool> expected_status(kAudioSources, true);
	expected_status[0] = false;

	MixAndCompare(frames, frame_info, expected_status);
	}

	TEST(AudioMixer, ActiveShouldMixBeforeLoud) {
	constexpr int kAudioSources =
	AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

	std::vector<AudioFrame> frames(kAudioSources);
	for (auto& frame : frames) {
	ResetFrame(&frame);
	}

	std::vector<MixerAudioSource::AudioFrameInfo> frame_info(
	kAudioSources, MixerAudioSource::AudioFrameInfo::kNormal);
	frames[0].vad_activity_ = AudioFrame::kVadPassive;
	std::fill(frames[0].data_, frames[0].data_ + kDefaultSampleRateHz / 100,
	std::numeric_limits<int16_t>::max());
	std::vector<bool> expected_status(kAudioSources, true);
	expected_status[0] = false;

	MixAndCompare(frames, frame_info, expected_status);
	}

	TEST(AudioMixer, UnmutedShouldMixBeforeLoud) {
	constexpr int kAudioSources =
	AudioMixer::kMaximumAmountOfMixedAudioSources + 1;

	std::vector<AudioFrame> frames(kAudioSources);
	for (auto& frame : frames) {
	ResetFrame(&frame);
	}

	std::vector<MixerAudioSource::AudioFrameInfo> frame_info(
	kAudioSources, MixerAudioSource::AudioFrameInfo::kNormal);
	frame_info[0] = MixerAudioSource::AudioFrameInfo::kMuted;
	std::fill(frames[0].data_, frames[0].data_ + kDefaultSampleRateHz / 100,
	std::numeric_limits<int16_t>::max());
	std::vector<bool> expected_status(kAudioSources, true);
	expected_status[0] = false;

	MixAndCompare(frames, frame_info, expected_status);
	}
	} // namespace webrtc