media/audio/audio_power_monitor_unittest.cc - chromium/chromium - Git at Google

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "media/audio/audio_power_monitor.h"

 #include <limits>

 #include "base/time/time.h"
 #include "media/base/audio_bus.h"
 #include "testing/gtest/include/gtest/gtest.h"

 namespace media {

 static const int kSampleRate = 48000;
 static const int kFramesPerBuffer = 128;

 static const int kTimeConstantMillis = 5;

 namespace {

 // Container for each parameterized test's data (input and expected results).
 class TestScenario {
  public:
   TestScenario(const float* data, int num_channels, int num_frames,
                float expected_power, bool expected_clipped)
       : expected_power_(expected_power), expected_clipped_(expected_clipped) {
     CreatePopulatedBuffer(data, num_channels, num_frames);
   }

   // Copy constructor and assignment operator for ::testing::Values(...).
   TestScenario(const TestScenario& other) { *this = other; }
   TestScenario& operator=(const TestScenario& other) {
     this->expected_power_ = other.expected_power_;
     this->expected_clipped_ = other.expected_clipped_;
     this->bus_ = AudioBus::Create(other.bus_->channels(), other.bus_->frames());
     other.bus_->CopyTo(this->bus_.get());
     return *this;
   }

   // Returns this TestScenario, but with a bad sample value placed in the middle
   // of channel 0.
   TestScenario WithABadSample(float bad_value) const {
     TestScenario result(*this);
     result.bus_->channel(0)[result.bus_->frames() / 2] = bad_value;
     return result;
   }

   const AudioBus& data() const {
     return *bus_;
   }

   float expected_power() const {
     return expected_power_;
   }

   bool expected_clipped() const {
     return expected_clipped_;
   }

  private:
   // Creates an AudioBus, sized and populated with kFramesPerBuffer frames of
   // data.  The given test |data| is repeated to fill the buffer.
   void CreatePopulatedBuffer(
       const float* data, int num_channels, int num_frames) {
     bus_ = AudioBus::Create(num_channels, kFramesPerBuffer);
     for (int ch = 0; ch < num_channels; ++ch) {
       for (int frames = 0; frames < kFramesPerBuffer; frames += num_frames) {
         const int num_to_copy = std::min(num_frames, kFramesPerBuffer - frames);
         memcpy(bus_->channel(ch) + frames, data + num_frames * ch,
                sizeof(float) * num_to_copy);
       }
     }
   }

   float expected_power_;
   bool expected_clipped_;
   scoped_ptr<AudioBus> bus_;
 };

 // Value printer for TestScenario.  Required to prevent Valgrind "access to
 // uninitialized memory" errors (http://crbug.com/263315).
 ::std::ostream& operator<<(::std::ostream& os, const TestScenario& ts) {
   return os << "{" << ts.data().channels() << "-channel signal} --> {"
             << ts.expected_power() << " dBFS, "
             << (ts.expected_clipped() ? "clipped" : "not clipped")
             << "}";
 }

 // An observer that receives power measurements.  Each power measurement should
 // should make progress towards the goal value.
 class MeasurementObserver {
  public:
   MeasurementObserver(float goal_power_measurement, bool goal_clipped)
       : goal_power_measurement_(goal_power_measurement),
         goal_clipped_(goal_clipped), measurement_count_(0),
         last_power_measurement_(AudioPowerMonitor::zero_power()),
         last_clipped_(false) {}

   int measurement_count() const {
     return measurement_count_;
   }

   float last_power_measurement() const {
     return last_power_measurement_;
   }

   bool last_clipped() const {
     return last_clipped_;
   }

   void OnPowerMeasured(float cur_power_measurement, bool clipped) {
     if (measurement_count_ == 0) {
       measurements_should_increase_ =
           (cur_power_measurement < goal_power_measurement_);
     } else {
       SCOPED_TRACE(::testing::Message()
                    << "Power: goal=" << goal_power_measurement_
                    << "; last=" << last_power_measurement_
                    << "; cur=" << cur_power_measurement);

       if (last_power_measurement_ != goal_power_measurement_) {
         if (measurements_should_increase_) {
           EXPECT_LE(last_power_measurement_, cur_power_measurement)
               << "Measurements should be monotonically increasing.";
         } else {
           EXPECT_GE(last_power_measurement_, cur_power_measurement)
               << "Measurements should be monotonically decreasing.";
         }
       } else {
         EXPECT_EQ(last_power_measurement_, cur_power_measurement)
             << "Measurements are numerically unstable at goal value.";
       }
     }

     last_power_measurement_ = cur_power_measurement;
     last_clipped_ = clipped;
     ++measurement_count_;
   }

  private:
   const float goal_power_measurement_;
   const bool goal_clipped_;
   int measurement_count_;
   bool measurements_should_increase_;
   float last_power_measurement_;
   bool last_clipped_;

   DISALLOW_COPY_AND_ASSIGN(MeasurementObserver);
 };

 }  // namespace

 class AudioPowerMonitorTest : public ::testing::TestWithParam<TestScenario> {
  public:
   AudioPowerMonitorTest()
       : power_monitor_(kSampleRate,
                        base::TimeDelta::FromMilliseconds(kTimeConstantMillis)) {
   }

   void FeedAndCheckExpectedPowerIsMeasured(
       const AudioBus& bus, float power, bool clipped) {
     // Feed the AudioPowerMonitor, read measurements from it, and record them in
     // MeasurementObserver.
     static const int kNumFeedIters = 100;
     MeasurementObserver observer(power, clipped);
     for (int i = 0; i < kNumFeedIters; ++i) {
       power_monitor_.Scan(bus, bus.frames());
       const std::pair<float, bool>& reading =
           power_monitor_.ReadCurrentPowerAndClip();
       observer.OnPowerMeasured(reading.first, reading.second);
     }

     // Check that the results recorded by the observer are the same whole-number
     // dBFS.
     EXPECT_EQ(static_cast<int>(power),
               static_cast<int>(observer.last_power_measurement()));
     EXPECT_EQ(clipped, observer.last_clipped());
   }

  private:
   AudioPowerMonitor power_monitor_;

   DISALLOW_COPY_AND_ASSIGN(AudioPowerMonitorTest);
 };

 TEST_P(AudioPowerMonitorTest, MeasuresPowerOfSignal) {
   const TestScenario& scenario = GetParam();

   scoped_ptr<AudioBus> zeroed_bus =
       AudioBus::Create(scenario.data().channels(), scenario.data().frames());
   zeroed_bus->Zero();

   // Send a "zero power" audio signal, then this scenario's audio signal, then
   // the "zero power" audio signal again; testing that the power monitor
   // measurements match expected values.
   FeedAndCheckExpectedPowerIsMeasured(
       *zeroed_bus, AudioPowerMonitor::zero_power(), false);
   FeedAndCheckExpectedPowerIsMeasured(
       scenario.data(), scenario.expected_power(), scenario.expected_clipped());
   FeedAndCheckExpectedPowerIsMeasured(
       *zeroed_bus, AudioPowerMonitor::zero_power(), false);
 }

 static const float kMonoSilentNoise[] = {
   0.01f, -0.01f
 };

 static const float kMonoMaxAmplitude[] = {
   1.0f
 };

 static const float kMonoMaxAmplitude2[] = {
   -1.0f, 1.0f
 };

 static const float kMonoHalfMaxAmplitude[] = {
   0.5f, -0.5f, 0.5f, -0.5f
 };

 static const float kMonoAmplitudeClipped[] = {
   2.0f, -2.0f
 };

 static const float kMonoMaxAmplitudeWithClip[] = {
   2.0f, 0.0, 0.0f, 0.0f
 };

 static const float kMonoMaxAmplitudeWithClip2[] = {
   4.0f, 0.0, 0.0f, 0.0f
 };

 static const float kStereoSilentNoise[] = {
   // left channel
   0.005f, -0.005f,
   // right channel
   0.005f, -0.005f
 };

 static const float kStereoMaxAmplitude[] = {
   // left channel
   1.0f, -1.0f,
   // right channel
   -1.0f, 1.0f
 };

 static const float kRightChannelMaxAmplitude[] = {
   // left channel
   0.0f, 0.0f, 0.0f, 0.0f,
   // right channel
   -1.0f, 1.0f, -1.0f, 1.0f
 };

 static const float kLeftChannelHalfMaxAmplitude[] = {
   // left channel
   0.5f, -0.5f, 0.5f, -0.5f,
   // right channel
   0.0f, 0.0f, 0.0f, 0.0f,
 };

 static const float kStereoMixed[] = {
   // left channel
   0.5f, -0.5f, 0.5f, -0.5f,
   // right channel
   -1.0f, 1.0f, -1.0f, 1.0f
 };

 static const float kStereoMixed2[] = {
   // left channel
   1.0f, -1.0f, 0.75f, -0.75f, 0.5f, -0.5f, 0.25f, -0.25f,
   // right channel
   0.25f, -0.25f, 0.5f, -0.5f, 0.75f, -0.75f, 1.0f, -1.0f
 };

 INSTANTIATE_TEST_CASE_P(
     Scenarios, AudioPowerMonitorTest,
     ::testing::Values(
          TestScenario(kMonoSilentNoise, 1, 2, -40, false),
          TestScenario(kMonoMaxAmplitude, 1, 1,
                       AudioPowerMonitor::max_power(), false),
          TestScenario(kMonoMaxAmplitude2, 1, 2,
                       AudioPowerMonitor::max_power(), false),
          TestScenario(kMonoHalfMaxAmplitude, 1, 4, -6, false),
          TestScenario(kMonoAmplitudeClipped, 1, 2,
                       AudioPowerMonitor::max_power(), true),
          TestScenario(kMonoMaxAmplitudeWithClip, 1, 4,
                       AudioPowerMonitor::max_power(), true),
          TestScenario(kMonoMaxAmplitudeWithClip2, 1, 4,
                       AudioPowerMonitor::max_power(), true),
          TestScenario(kMonoSilentNoise, 1, 2,
                       AudioPowerMonitor::zero_power(), false).
              WithABadSample(std::numeric_limits<float>::infinity()),
          TestScenario(kMonoHalfMaxAmplitude, 1, 4,
                       AudioPowerMonitor::zero_power(), false).
              WithABadSample(std::numeric_limits<float>::quiet_NaN()),
          TestScenario(kStereoSilentNoise, 2, 2, -46, false),
          TestScenario(kStereoMaxAmplitude, 2, 2,
                       AudioPowerMonitor::max_power(), false),
          TestScenario(kRightChannelMaxAmplitude, 2, 4, -3, false),
          TestScenario(kLeftChannelHalfMaxAmplitude, 2, 4, -9, false),
          TestScenario(kStereoMixed, 2, 4, -2, false),
          TestScenario(kStereoMixed2, 2, 8, -3, false)));

 }  // namespace media
	// Copyright 2013 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "media/audio/audio_power_monitor.h"

	#include <limits>

	#include "base/time/time.h"
	#include "media/base/audio_bus.h"
	#include "testing/gtest/include/gtest/gtest.h"

	namespace media {

	static const int kSampleRate = 48000;
	static const int kFramesPerBuffer = 128;

	static const int kTimeConstantMillis = 5;

	namespace {

	// Container for each parameterized test's data (input and expected results).
	class TestScenario {
	public:
	TestScenario(const float* data, int num_channels, int num_frames,
	float expected_power, bool expected_clipped)
	: expected_power_(expected_power), expected_clipped_(expected_clipped) {
	CreatePopulatedBuffer(data, num_channels, num_frames);
	}

	// Copy constructor and assignment operator for ::testing::Values(...).
	TestScenario(const TestScenario& other) { *this = other; }
	TestScenario& operator=(const TestScenario& other) {
	this->expected_power_ = other.expected_power_;
	this->expected_clipped_ = other.expected_clipped_;
	this->bus_ = AudioBus::Create(other.bus_->channels(), other.bus_->frames());
	other.bus_->CopyTo(this->bus_.get());
	return *this;
	}

	// Returns this TestScenario, but with a bad sample value placed in the middle
	// of channel 0.
	TestScenario WithABadSample(float bad_value) const {
	TestScenario result(*this);
	result.bus_->channel(0)[result.bus_->frames() / 2] = bad_value;
	return result;
	}

	const AudioBus& data() const {
	return *bus_;
	}

	float expected_power() const {
	return expected_power_;
	}

	bool expected_clipped() const {
	return expected_clipped_;
	}

	private:
	// Creates an AudioBus, sized and populated with kFramesPerBuffer frames of
	// data. The given test \|data\| is repeated to fill the buffer.
	void CreatePopulatedBuffer(
	const float* data, int num_channels, int num_frames) {
	bus_ = AudioBus::Create(num_channels, kFramesPerBuffer);
	for (int ch = 0; ch < num_channels; ++ch) {
	for (int frames = 0; frames < kFramesPerBuffer; frames += num_frames) {
	const int num_to_copy = std::min(num_frames, kFramesPerBuffer - frames);
	memcpy(bus_->channel(ch) + frames, data + num_frames * ch,
	sizeof(float) * num_to_copy);
	}
	}
	}

	float expected_power_;
	bool expected_clipped_;
	scoped_ptr<AudioBus> bus_;
	};

	// Value printer for TestScenario. Required to prevent Valgrind "access to
	// uninitialized memory" errors (http://crbug.com/263315).
	::std::ostream& operator<<(::std::ostream& os, const TestScenario& ts) {
	return os << "{" << ts.data().channels() << "-channel signal} --> {"
	<< ts.expected_power() << " dBFS, "
	<< (ts.expected_clipped() ? "clipped" : "not clipped")
	<< "}";
	}

	// An observer that receives power measurements. Each power measurement should
	// should make progress towards the goal value.
	class MeasurementObserver {
	public:
	MeasurementObserver(float goal_power_measurement, bool goal_clipped)
	: goal_power_measurement_(goal_power_measurement),
	goal_clipped_(goal_clipped), measurement_count_(0),
	last_power_measurement_(AudioPowerMonitor::zero_power()),
	last_clipped_(false) {}

	int measurement_count() const {
	return measurement_count_;
	}

	float last_power_measurement() const {
	return last_power_measurement_;
	}

	bool last_clipped() const {
	return last_clipped_;
	}

	void OnPowerMeasured(float cur_power_measurement, bool clipped) {
	if (measurement_count_ == 0) {
	measurements_should_increase_ =
	(cur_power_measurement < goal_power_measurement_);
	} else {
	SCOPED_TRACE(::testing::Message()
	<< "Power: goal=" << goal_power_measurement_
	<< "; last=" << last_power_measurement_
	<< "; cur=" << cur_power_measurement);

	if (last_power_measurement_ != goal_power_measurement_) {
	if (measurements_should_increase_) {
	EXPECT_LE(last_power_measurement_, cur_power_measurement)
	<< "Measurements should be monotonically increasing.";
	} else {
	EXPECT_GE(last_power_measurement_, cur_power_measurement)
	<< "Measurements should be monotonically decreasing.";
	}
	} else {
	EXPECT_EQ(last_power_measurement_, cur_power_measurement)
	<< "Measurements are numerically unstable at goal value.";
	}
	}

	last_power_measurement_ = cur_power_measurement;
	last_clipped_ = clipped;
	++measurement_count_;
	}

	private:
	const float goal_power_measurement_;
	const bool goal_clipped_;
	int measurement_count_;
	bool measurements_should_increase_;
	float last_power_measurement_;
	bool last_clipped_;

	DISALLOW_COPY_AND_ASSIGN(MeasurementObserver);
	};

	} // namespace

	class AudioPowerMonitorTest : public ::testing::TestWithParam<TestScenario> {
	public:
	AudioPowerMonitorTest()
	: power_monitor_(kSampleRate,
	base::TimeDelta::FromMilliseconds(kTimeConstantMillis)) {
	}

	void FeedAndCheckExpectedPowerIsMeasured(
	const AudioBus& bus, float power, bool clipped) {
	// Feed the AudioPowerMonitor, read measurements from it, and record them in
	// MeasurementObserver.
	static const int kNumFeedIters = 100;
	MeasurementObserver observer(power, clipped);
	for (int i = 0; i < kNumFeedIters; ++i) {
	power_monitor_.Scan(bus, bus.frames());
	const std::pair<float, bool>& reading =
	power_monitor_.ReadCurrentPowerAndClip();
	observer.OnPowerMeasured(reading.first, reading.second);
	}

	// Check that the results recorded by the observer are the same whole-number
	// dBFS.
	EXPECT_EQ(static_cast<int>(power),
	static_cast<int>(observer.last_power_measurement()));
	EXPECT_EQ(clipped, observer.last_clipped());
	}

	private:
	AudioPowerMonitor power_monitor_;

	DISALLOW_COPY_AND_ASSIGN(AudioPowerMonitorTest);
	};

	TEST_P(AudioPowerMonitorTest, MeasuresPowerOfSignal) {
	const TestScenario& scenario = GetParam();

	scoped_ptr<AudioBus> zeroed_bus =
	AudioBus::Create(scenario.data().channels(), scenario.data().frames());
	zeroed_bus->Zero();

	// Send a "zero power" audio signal, then this scenario's audio signal, then
	// the "zero power" audio signal again; testing that the power monitor
	// measurements match expected values.
	FeedAndCheckExpectedPowerIsMeasured(
	*zeroed_bus, AudioPowerMonitor::zero_power(), false);
	FeedAndCheckExpectedPowerIsMeasured(
	scenario.data(), scenario.expected_power(), scenario.expected_clipped());
	FeedAndCheckExpectedPowerIsMeasured(
	*zeroed_bus, AudioPowerMonitor::zero_power(), false);
	}

	static const float kMonoSilentNoise[] = {
	0.01f, -0.01f
	};

	static const float kMonoMaxAmplitude[] = {
	1.0f
	};

	static const float kMonoMaxAmplitude2[] = {
	-1.0f, 1.0f
	};

	static const float kMonoHalfMaxAmplitude[] = {
	0.5f, -0.5f, 0.5f, -0.5f
	};

	static const float kMonoAmplitudeClipped[] = {
	2.0f, -2.0f
	};

	static const float kMonoMaxAmplitudeWithClip[] = {
	2.0f, 0.0, 0.0f, 0.0f
	};

	static const float kMonoMaxAmplitudeWithClip2[] = {
	4.0f, 0.0, 0.0f, 0.0f
	};

	static const float kStereoSilentNoise[] = {
	// left channel
	0.005f, -0.005f,
	// right channel
	0.005f, -0.005f
	};

	static const float kStereoMaxAmplitude[] = {
	// left channel
	1.0f, -1.0f,
	// right channel
	-1.0f, 1.0f
	};

	static const float kRightChannelMaxAmplitude[] = {
	// left channel
	0.0f, 0.0f, 0.0f, 0.0f,
	// right channel
	-1.0f, 1.0f, -1.0f, 1.0f
	};

	static const float kLeftChannelHalfMaxAmplitude[] = {
	// left channel
	0.5f, -0.5f, 0.5f, -0.5f,
	// right channel
	0.0f, 0.0f, 0.0f, 0.0f,
	};

	static const float kStereoMixed[] = {
	// left channel
	0.5f, -0.5f, 0.5f, -0.5f,
	// right channel
	-1.0f, 1.0f, -1.0f, 1.0f
	};

	static const float kStereoMixed2[] = {
	// left channel
	1.0f, -1.0f, 0.75f, -0.75f, 0.5f, -0.5f, 0.25f, -0.25f,
	// right channel
	0.25f, -0.25f, 0.5f, -0.5f, 0.75f, -0.75f, 1.0f, -1.0f
	};

	INSTANTIATE_TEST_CASE_P(
	Scenarios, AudioPowerMonitorTest,
	::testing::Values(
	TestScenario(kMonoSilentNoise, 1, 2, -40, false),
	TestScenario(kMonoMaxAmplitude, 1, 1,
	AudioPowerMonitor::max_power(), false),
	TestScenario(kMonoMaxAmplitude2, 1, 2,
	AudioPowerMonitor::max_power(), false),
	TestScenario(kMonoHalfMaxAmplitude, 1, 4, -6, false),
	TestScenario(kMonoAmplitudeClipped, 1, 2,
	AudioPowerMonitor::max_power(), true),
	TestScenario(kMonoMaxAmplitudeWithClip, 1, 4,
	AudioPowerMonitor::max_power(), true),
	TestScenario(kMonoMaxAmplitudeWithClip2, 1, 4,
	AudioPowerMonitor::max_power(), true),
	TestScenario(kMonoSilentNoise, 1, 2,
	AudioPowerMonitor::zero_power(), false).
	WithABadSample(std::numeric_limits<float>::infinity()),
	TestScenario(kMonoHalfMaxAmplitude, 1, 4,
	AudioPowerMonitor::zero_power(), false).
	WithABadSample(std::numeric_limits<float>::quiet_NaN()),
	TestScenario(kStereoSilentNoise, 2, 2, -46, false),
	TestScenario(kStereoMaxAmplitude, 2, 2,
	AudioPowerMonitor::max_power(), false),
	TestScenario(kRightChannelMaxAmplitude, 2, 4, -3, false),
	TestScenario(kLeftChannelHalfMaxAmplitude, 2, 4, -9, false),
	TestScenario(kStereoMixed, 2, 4, -2, false),
	TestScenario(kStereoMixed2, 2, 8, -3, false)));

	} // namespace media