webrtc/modules/video_coding/utility/quality_scaler_unittest.cc - src - Git at Google

 /*
  *  Copyright (c) 2014 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 "webrtc/modules/video_coding/utility/quality_scaler.h"

 #include "testing/gtest/include/gtest/gtest.h"

 namespace webrtc {
 namespace {
 static const int kNumSeconds = 10;
 static const int kWidth = 1920;
 static const int kHalfWidth = kWidth / 2;
 static const int kHeight = 1080;
 static const int kFramerate = 30;
 static const int kLowQp = 15;
 static const int kNormalQp = 30;
 static const int kLowQpThreshold = 18;
 static const int kHighQp = 40;
 static const int kDisabledBadQpThreshold = 64;
 static const int kLowInitialBitrateKbps = 300;
 // These values need to be in sync with corresponding constants
 // in quality_scaler.cc
 static const int kMeasureSecondsFastUpscale = 2;
 static const int kMeasureSecondsUpscale = 5;
 static const int kMeasureSecondsDownscale = 5;
 static const int kMinDownscaleDimension = 140;
 }  // namespace

 class QualityScalerTest : public ::testing::Test {
  protected:
   enum ScaleDirection {
     kKeepScaleAtHighQp,
     kScaleDown,
     kScaleDownAboveHighQp,
     kScaleUp
   };

   QualityScalerTest() {
     input_frame_.CreateEmptyFrame(kWidth, kHeight, kWidth, kHalfWidth,
                                   kHalfWidth);
     qs_.Init(kLowQpThreshold, kHighQp, 0, 0, 0, kFramerate);
     qs_.OnEncodeFrame(input_frame_);
   }

   bool TriggerScale(ScaleDirection scale_direction) {
     qs_.OnEncodeFrame(input_frame_);
     int initial_width = qs_.GetScaledResolution().width;
     for (int i = 0; i < kFramerate * kNumSeconds; ++i) {
       switch (scale_direction) {
         case kScaleUp:
           qs_.ReportQP(kLowQp);
           break;
         case kScaleDown:
           qs_.ReportDroppedFrame();
           break;
         case kKeepScaleAtHighQp:
           qs_.ReportQP(kHighQp);
           break;
         case kScaleDownAboveHighQp:
           qs_.ReportQP(kHighQp + 1);
           break;
       }
       qs_.OnEncodeFrame(input_frame_);
       if (qs_.GetScaledResolution().width != initial_width)
         return true;
     }

     return false;
   }

   void ExpectOriginalFrame() {
     EXPECT_EQ(&input_frame_, &qs_.GetScaledFrame(input_frame_))
         << "Using scaled frame instead of original input.";
   }

   void ExpectScaleUsingReportedResolution() {
     qs_.OnEncodeFrame(input_frame_);
     QualityScaler::Resolution res = qs_.GetScaledResolution();
     const VideoFrame& scaled_frame = qs_.GetScaledFrame(input_frame_);
     EXPECT_EQ(res.width, scaled_frame.width());
     EXPECT_EQ(res.height, scaled_frame.height());
   }

   void ContinuouslyDownscalesByHalfDimensionsAndBackUp();

   void DoesNotDownscaleFrameDimensions(int width, int height);

   void DownscaleEndsAt(int input_width,
                        int input_height,
                        int end_width,
                        int end_height);

   QualityScaler qs_;
   VideoFrame input_frame_;
 };

 TEST_F(QualityScalerTest, UsesOriginalFrameInitially) {
   ExpectOriginalFrame();
 }

 TEST_F(QualityScalerTest, ReportsOriginalResolutionInitially) {
   qs_.OnEncodeFrame(input_frame_);
   QualityScaler::Resolution res = qs_.GetScaledResolution();
   EXPECT_EQ(input_frame_.width(), res.width);
   EXPECT_EQ(input_frame_.height(), res.height);
 }

 TEST_F(QualityScalerTest, DownscalesAfterContinuousFramedrop) {
   EXPECT_TRUE(TriggerScale(kScaleDown)) << "No downscale within " << kNumSeconds
                                         << " seconds.";
   QualityScaler::Resolution res = qs_.GetScaledResolution();
   EXPECT_LT(res.width, input_frame_.width());
   EXPECT_LT(res.height, input_frame_.height());
 }

 TEST_F(QualityScalerTest, KeepsScaleAtHighQp) {
   EXPECT_FALSE(TriggerScale(kKeepScaleAtHighQp))
       << "Downscale at high threshold which should keep scale.";
   QualityScaler::Resolution res = qs_.GetScaledResolution();
   EXPECT_EQ(res.width, input_frame_.width());
   EXPECT_EQ(res.height, input_frame_.height());
 }

 TEST_F(QualityScalerTest, DownscalesAboveHighQp) {
   EXPECT_TRUE(TriggerScale(kScaleDownAboveHighQp))
       << "No downscale within " << kNumSeconds << " seconds.";
   QualityScaler::Resolution res = qs_.GetScaledResolution();
   EXPECT_LT(res.width, input_frame_.width());
   EXPECT_LT(res.height, input_frame_.height());
 }

 TEST_F(QualityScalerTest, DownscalesAfterTwoThirdsFramedrop) {
   for (int i = 0; i < kFramerate * kNumSeconds / 3; ++i) {
     qs_.ReportQP(kNormalQp);
     qs_.ReportDroppedFrame();
     qs_.ReportDroppedFrame();
     qs_.OnEncodeFrame(input_frame_);
     if (qs_.GetScaledResolution().width < input_frame_.width())
       return;
   }

   FAIL() << "No downscale within " << kNumSeconds << " seconds.";
 }

 TEST_F(QualityScalerTest, DoesNotDownscaleOnNormalQp) {
   for (int i = 0; i < kFramerate * kNumSeconds; ++i) {
     qs_.ReportQP(kNormalQp);
     qs_.OnEncodeFrame(input_frame_);
     ASSERT_EQ(input_frame_.width(), qs_.GetScaledResolution().width)
         << "Unexpected scale on half framedrop.";
   }
 }

 TEST_F(QualityScalerTest, DoesNotDownscaleAfterHalfFramedrop) {
   for (int i = 0; i < kFramerate * kNumSeconds / 2; ++i) {
     qs_.ReportQP(kNormalQp);
     qs_.OnEncodeFrame(input_frame_);
     ASSERT_EQ(input_frame_.width(), qs_.GetScaledResolution().width)
         << "Unexpected scale on half framedrop.";

     qs_.ReportDroppedFrame();
     qs_.OnEncodeFrame(input_frame_);
     ASSERT_EQ(input_frame_.width(), qs_.GetScaledResolution().width)
         << "Unexpected scale on half framedrop.";
   }
 }

 void QualityScalerTest::ContinuouslyDownscalesByHalfDimensionsAndBackUp() {
   const int initial_min_dimension = input_frame_.width() < input_frame_.height()
                                         ? input_frame_.width()
                                         : input_frame_.height();
   int min_dimension = initial_min_dimension;
   int current_shift = 0;
   // Drop all frames to force-trigger downscaling.
   while (min_dimension >= 2 * kMinDownscaleDimension) {
     EXPECT_TRUE(TriggerScale(kScaleDown)) << "No downscale within "
                                           << kNumSeconds << " seconds.";
     qs_.OnEncodeFrame(input_frame_);
     QualityScaler::Resolution res = qs_.GetScaledResolution();
     min_dimension = res.width < res.height ? res.width : res.height;
     ++current_shift;
     ASSERT_EQ(input_frame_.width() >> current_shift, res.width);
     ASSERT_EQ(input_frame_.height() >> current_shift, res.height);
     ExpectScaleUsingReportedResolution();
   }

   // Make sure we can scale back with good-quality frames.
   while (min_dimension < initial_min_dimension) {
     EXPECT_TRUE(TriggerScale(kScaleUp)) << "No upscale within " << kNumSeconds
                                         << " seconds.";
     qs_.OnEncodeFrame(input_frame_);
     QualityScaler::Resolution res = qs_.GetScaledResolution();
     min_dimension = res.width < res.height ? res.width : res.height;
     --current_shift;
     ASSERT_EQ(input_frame_.width() >> current_shift, res.width);
     ASSERT_EQ(input_frame_.height() >> current_shift, res.height);
     ExpectScaleUsingReportedResolution();
   }

   // Verify we don't start upscaling after further low use.
   for (int i = 0; i < kFramerate * kNumSeconds; ++i) {
     qs_.ReportQP(kLowQp);
     ExpectOriginalFrame();
   }
 }

 TEST_F(QualityScalerTest, ContinuouslyDownscalesByHalfDimensionsAndBackUp) {
   ContinuouslyDownscalesByHalfDimensionsAndBackUp();
 }

 TEST_F(QualityScalerTest,
        ContinuouslyDownscalesOddResolutionsByHalfDimensionsAndBackUp) {
   const int kOddWidth = 517;
   const int kHalfOddWidth = (kOddWidth + 1) / 2;
   const int kOddHeight = 1239;
   input_frame_.CreateEmptyFrame(kOddWidth, kOddHeight, kOddWidth, kHalfOddWidth,
                                 kHalfOddWidth);
   ContinuouslyDownscalesByHalfDimensionsAndBackUp();
 }

 void QualityScalerTest::DoesNotDownscaleFrameDimensions(int width, int height) {
   input_frame_.CreateEmptyFrame(width, height, width, (width + 1) / 2,
                                 (width + 1) / 2);

   for (int i = 0; i < kFramerate * kNumSeconds; ++i) {
     qs_.ReportDroppedFrame();
     qs_.OnEncodeFrame(input_frame_);
     ASSERT_EQ(input_frame_.width(), qs_.GetScaledResolution().width)
         << "Unexpected scale of minimal-size frame.";
   }
 }

 TEST_F(QualityScalerTest, DoesNotDownscaleFrom1PxWidth) {
   DoesNotDownscaleFrameDimensions(1, kHeight);
 }

 TEST_F(QualityScalerTest, DoesNotDownscaleFrom1PxHeight) {
   DoesNotDownscaleFrameDimensions(kWidth, 1);
 }

 TEST_F(QualityScalerTest, DoesNotDownscaleFrom1Px) {
   DoesNotDownscaleFrameDimensions(1, 1);
 }

 TEST_F(QualityScalerTest, DoesNotDownscaleBelow2xDefaultMinDimensionsWidth) {
   DoesNotDownscaleFrameDimensions(
       2 * kMinDownscaleDimension - 1, 1000);
 }

 TEST_F(QualityScalerTest, DoesNotDownscaleBelow2xDefaultMinDimensionsHeight) {
   DoesNotDownscaleFrameDimensions(
       1000, 2 * kMinDownscaleDimension - 1);
 }

 TEST_F(QualityScalerTest, DownscaleToVgaOnLowInitialBitrate) {
   static const int kWidth720p = 1280;
   static const int kHeight720p = 720;
   static const int kInitialBitrateKbps = 300;
   input_frame_.CreateEmptyFrame(kWidth720p, kHeight720p, kWidth720p,
                                 kWidth720p / 2, kWidth720p / 2);
   qs_.Init(kLowQpThreshold, kDisabledBadQpThreshold, kInitialBitrateKbps,
            kWidth720p, kHeight720p, kFramerate);
   qs_.OnEncodeFrame(input_frame_);
   int init_width = qs_.GetScaledResolution().width;
   int init_height = qs_.GetScaledResolution().height;
   EXPECT_EQ(640, init_width);
   EXPECT_EQ(360, init_height);
 }

 TEST_F(QualityScalerTest, DownscaleToQvgaOnLowerInitialBitrate) {
   static const int kWidth720p = 1280;
   static const int kHeight720p = 720;
   static const int kInitialBitrateKbps = 200;
   input_frame_.CreateEmptyFrame(kWidth720p, kHeight720p, kWidth720p,
                                 kWidth720p / 2, kWidth720p / 2);
   qs_.Init(kLowQpThreshold, kDisabledBadQpThreshold, kInitialBitrateKbps,
            kWidth720p, kHeight720p, kFramerate);
   qs_.OnEncodeFrame(input_frame_);
   int init_width = qs_.GetScaledResolution().width;
   int init_height = qs_.GetScaledResolution().height;
   EXPECT_EQ(320, init_width);
   EXPECT_EQ(180, init_height);
 }

 TEST_F(QualityScalerTest, DownscaleAfterMeasuredSecondsThenSlowerBackUp) {
   qs_.Init(kLowQpThreshold, kHighQp, 0, kWidth, kHeight, kFramerate);
   qs_.OnEncodeFrame(input_frame_);
   QualityScaler::Resolution initial_res = qs_.GetScaledResolution();

   // Should not downscale if less than kMeasureSecondsDownscale seconds passed.
   for (int i = 0; i < kFramerate * kMeasureSecondsDownscale - 1; ++i) {
     qs_.ReportQP(kHighQp + 1);
     qs_.OnEncodeFrame(input_frame_);
   }
   EXPECT_EQ(initial_res.width, qs_.GetScaledResolution().width);
   EXPECT_EQ(initial_res.height, qs_.GetScaledResolution().height);

   // Should downscale if more than kMeasureSecondsDownscale seconds passed (add
   // last frame).
   qs_.ReportQP(kHighQp + 1);
   qs_.OnEncodeFrame(input_frame_);
   EXPECT_GT(initial_res.width, qs_.GetScaledResolution().width);
   EXPECT_GT(initial_res.height, qs_.GetScaledResolution().height);

   // Should not upscale if less than kMeasureSecondsUpscale seconds passed since
   // we saw issues initially (have already gone down).
   for (int i = 0; i < kFramerate * kMeasureSecondsUpscale - 1; ++i) {
     qs_.ReportQP(kLowQp);
     qs_.OnEncodeFrame(input_frame_);
   }
   EXPECT_GT(initial_res.width, qs_.GetScaledResolution().width);
   EXPECT_GT(initial_res.height, qs_.GetScaledResolution().height);

   // Should upscale (back to initial) if kMeasureSecondsUpscale seconds passed
   // (add last frame).
   qs_.ReportQP(kLowQp);
   qs_.OnEncodeFrame(input_frame_);
   EXPECT_EQ(initial_res.width, qs_.GetScaledResolution().width);
   EXPECT_EQ(initial_res.height, qs_.GetScaledResolution().height);
 }

 TEST_F(QualityScalerTest, UpscaleQuicklyInitiallyAfterMeasuredSeconds) {
   qs_.Init(kLowQpThreshold, kHighQp, kLowInitialBitrateKbps, kWidth, kHeight,
            kFramerate);
   qs_.OnEncodeFrame(input_frame_);
   QualityScaler::Resolution initial_res = qs_.GetScaledResolution();

   // Should not upscale if less than kMeasureSecondsFastUpscale seconds passed.
   for (int i = 0; i < kFramerate * kMeasureSecondsFastUpscale - 1; ++i) {
     qs_.ReportQP(kLowQp);
     qs_.OnEncodeFrame(input_frame_);
   }
   EXPECT_EQ(initial_res.width, qs_.GetScaledResolution().width);
   EXPECT_EQ(initial_res.height, qs_.GetScaledResolution().height);

   // Should upscale if kMeasureSecondsFastUpscale seconds passed (add last
   // frame).
   qs_.ReportQP(kLowQp);
   qs_.OnEncodeFrame(input_frame_);
   EXPECT_LT(initial_res.width, qs_.GetScaledResolution().width);
   EXPECT_LT(initial_res.height, qs_.GetScaledResolution().height);
 }

 void QualityScalerTest::DownscaleEndsAt(int input_width,
                                         int input_height,
                                         int end_width,
                                         int end_height) {
   // Create a frame with 2x expected end width/height to verify that we can
   // scale down to expected end width/height.
   input_frame_.CreateEmptyFrame(input_width, input_height, input_width,
                                 (input_width + 1) / 2, (input_width + 1) / 2);

   int last_width = input_width;
   int last_height = input_height;
   // Drop all frames to force-trigger downscaling.
   while (true) {
     TriggerScale(kScaleDown);
     QualityScaler::Resolution res = qs_.GetScaledResolution();
     if (last_width == res.width) {
       EXPECT_EQ(last_height, res.height);
       EXPECT_EQ(end_width, res.width);
       EXPECT_EQ(end_height, res.height);
       break;
     }
     last_width = res.width;
     last_height = res.height;
   }
 }

 TEST_F(QualityScalerTest, DownscalesTo320x180) {
   DownscaleEndsAt(640, 360, 320, 180);
 }

 TEST_F(QualityScalerTest, DownscalesTo180x320) {
   DownscaleEndsAt(360, 640, 180, 320);
 }

 TEST_F(QualityScalerTest, DownscalesFrom1280x720To320x180) {
   DownscaleEndsAt(1280, 720, 320, 180);
 }

 TEST_F(QualityScalerTest, DoesntDownscaleInitialQvga) {
   DownscaleEndsAt(320, 180, 320, 180);
 }

 }  // namespace webrtc
	/*
	* Copyright (c) 2014 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 "webrtc/modules/video_coding/utility/quality_scaler.h"

	#include "testing/gtest/include/gtest/gtest.h"

	namespace webrtc {
	namespace {
	static const int kNumSeconds = 10;
	static const int kWidth = 1920;
	static const int kHalfWidth = kWidth / 2;
	static const int kHeight = 1080;
	static const int kFramerate = 30;
	static const int kLowQp = 15;
	static const int kNormalQp = 30;
	static const int kLowQpThreshold = 18;
	static const int kHighQp = 40;
	static const int kDisabledBadQpThreshold = 64;
	static const int kLowInitialBitrateKbps = 300;
	// These values need to be in sync with corresponding constants
	// in quality_scaler.cc
	static const int kMeasureSecondsFastUpscale = 2;
	static const int kMeasureSecondsUpscale = 5;
	static const int kMeasureSecondsDownscale = 5;
	static const int kMinDownscaleDimension = 140;
	} // namespace

	class QualityScalerTest : public ::testing::Test {
	protected:
	enum ScaleDirection {
	kKeepScaleAtHighQp,
	kScaleDown,
	kScaleDownAboveHighQp,
	kScaleUp
	};

	QualityScalerTest() {
	input_frame_.CreateEmptyFrame(kWidth, kHeight, kWidth, kHalfWidth,
	kHalfWidth);
	qs_.Init(kLowQpThreshold, kHighQp, 0, 0, 0, kFramerate);
	qs_.OnEncodeFrame(input_frame_);
	}

	bool TriggerScale(ScaleDirection scale_direction) {
	qs_.OnEncodeFrame(input_frame_);
	int initial_width = qs_.GetScaledResolution().width;
	for (int i = 0; i < kFramerate * kNumSeconds; ++i) {
	switch (scale_direction) {
	case kScaleUp:
	qs_.ReportQP(kLowQp);
	break;
	case kScaleDown:
	qs_.ReportDroppedFrame();
	break;
	case kKeepScaleAtHighQp:
	qs_.ReportQP(kHighQp);
	break;
	case kScaleDownAboveHighQp:
	qs_.ReportQP(kHighQp + 1);
	break;
	}
	qs_.OnEncodeFrame(input_frame_);
	if (qs_.GetScaledResolution().width != initial_width)
	return true;
	}

	return false;
	}

	void ExpectOriginalFrame() {
	EXPECT_EQ(&input_frame_, &qs_.GetScaledFrame(input_frame_))
	<< "Using scaled frame instead of original input.";
	}

	void ExpectScaleUsingReportedResolution() {
	qs_.OnEncodeFrame(input_frame_);
	QualityScaler::Resolution res = qs_.GetScaledResolution();
	const VideoFrame& scaled_frame = qs_.GetScaledFrame(input_frame_);
	EXPECT_EQ(res.width, scaled_frame.width());
	EXPECT_EQ(res.height, scaled_frame.height());
	}

	void ContinuouslyDownscalesByHalfDimensionsAndBackUp();

	void DoesNotDownscaleFrameDimensions(int width, int height);

	void DownscaleEndsAt(int input_width,
	int input_height,
	int end_width,
	int end_height);

	QualityScaler qs_;
	VideoFrame input_frame_;
	};

	TEST_F(QualityScalerTest, UsesOriginalFrameInitially) {
	ExpectOriginalFrame();
	}

	TEST_F(QualityScalerTest, ReportsOriginalResolutionInitially) {
	qs_.OnEncodeFrame(input_frame_);
	QualityScaler::Resolution res = qs_.GetScaledResolution();
	EXPECT_EQ(input_frame_.width(), res.width);
	EXPECT_EQ(input_frame_.height(), res.height);
	}

	TEST_F(QualityScalerTest, DownscalesAfterContinuousFramedrop) {
	EXPECT_TRUE(TriggerScale(kScaleDown)) << "No downscale within " << kNumSeconds
	<< " seconds.";
	QualityScaler::Resolution res = qs_.GetScaledResolution();
	EXPECT_LT(res.width, input_frame_.width());
	EXPECT_LT(res.height, input_frame_.height());
	}

	TEST_F(QualityScalerTest, KeepsScaleAtHighQp) {
	EXPECT_FALSE(TriggerScale(kKeepScaleAtHighQp))
	<< "Downscale at high threshold which should keep scale.";
	QualityScaler::Resolution res = qs_.GetScaledResolution();
	EXPECT_EQ(res.width, input_frame_.width());
	EXPECT_EQ(res.height, input_frame_.height());
	}

	TEST_F(QualityScalerTest, DownscalesAboveHighQp) {
	EXPECT_TRUE(TriggerScale(kScaleDownAboveHighQp))
	<< "No downscale within " << kNumSeconds << " seconds.";
	QualityScaler::Resolution res = qs_.GetScaledResolution();
	EXPECT_LT(res.width, input_frame_.width());
	EXPECT_LT(res.height, input_frame_.height());
	}

	TEST_F(QualityScalerTest, DownscalesAfterTwoThirdsFramedrop) {
	for (int i = 0; i < kFramerate * kNumSeconds / 3; ++i) {
	qs_.ReportQP(kNormalQp);
	qs_.ReportDroppedFrame();
	qs_.ReportDroppedFrame();
	qs_.OnEncodeFrame(input_frame_);
	if (qs_.GetScaledResolution().width < input_frame_.width())
	return;
	}

	FAIL() << "No downscale within " << kNumSeconds << " seconds.";
	}

	TEST_F(QualityScalerTest, DoesNotDownscaleOnNormalQp) {
	for (int i = 0; i < kFramerate * kNumSeconds; ++i) {
	qs_.ReportQP(kNormalQp);
	qs_.OnEncodeFrame(input_frame_);
	ASSERT_EQ(input_frame_.width(), qs_.GetScaledResolution().width)
	<< "Unexpected scale on half framedrop.";
	}
	}

	TEST_F(QualityScalerTest, DoesNotDownscaleAfterHalfFramedrop) {
	for (int i = 0; i < kFramerate * kNumSeconds / 2; ++i) {
	qs_.ReportQP(kNormalQp);
	qs_.OnEncodeFrame(input_frame_);
	ASSERT_EQ(input_frame_.width(), qs_.GetScaledResolution().width)
	<< "Unexpected scale on half framedrop.";

	qs_.ReportDroppedFrame();
	qs_.OnEncodeFrame(input_frame_);
	ASSERT_EQ(input_frame_.width(), qs_.GetScaledResolution().width)
	<< "Unexpected scale on half framedrop.";
	}
	}

	void QualityScalerTest::ContinuouslyDownscalesByHalfDimensionsAndBackUp() {
	const int initial_min_dimension = input_frame_.width() < input_frame_.height()
	? input_frame_.width()
	: input_frame_.height();
	int min_dimension = initial_min_dimension;
	int current_shift = 0;
	// Drop all frames to force-trigger downscaling.
	while (min_dimension >= 2 * kMinDownscaleDimension) {
	EXPECT_TRUE(TriggerScale(kScaleDown)) << "No downscale within "
	<< kNumSeconds << " seconds.";
	qs_.OnEncodeFrame(input_frame_);
	QualityScaler::Resolution res = qs_.GetScaledResolution();
	min_dimension = res.width < res.height ? res.width : res.height;
	++current_shift;
	ASSERT_EQ(input_frame_.width() >> current_shift, res.width);
	ASSERT_EQ(input_frame_.height() >> current_shift, res.height);
	ExpectScaleUsingReportedResolution();
	}

	// Make sure we can scale back with good-quality frames.
	while (min_dimension < initial_min_dimension) {
	EXPECT_TRUE(TriggerScale(kScaleUp)) << "No upscale within " << kNumSeconds
	<< " seconds.";
	qs_.OnEncodeFrame(input_frame_);
	QualityScaler::Resolution res = qs_.GetScaledResolution();
	min_dimension = res.width < res.height ? res.width : res.height;
	--current_shift;
	ASSERT_EQ(input_frame_.width() >> current_shift, res.width);
	ASSERT_EQ(input_frame_.height() >> current_shift, res.height);
	ExpectScaleUsingReportedResolution();
	}

	// Verify we don't start upscaling after further low use.
	for (int i = 0; i < kFramerate * kNumSeconds; ++i) {
	qs_.ReportQP(kLowQp);
	ExpectOriginalFrame();
	}
	}

	TEST_F(QualityScalerTest, ContinuouslyDownscalesByHalfDimensionsAndBackUp) {
	ContinuouslyDownscalesByHalfDimensionsAndBackUp();
	}

	TEST_F(QualityScalerTest,
	ContinuouslyDownscalesOddResolutionsByHalfDimensionsAndBackUp) {
	const int kOddWidth = 517;
	const int kHalfOddWidth = (kOddWidth + 1) / 2;
	const int kOddHeight = 1239;
	input_frame_.CreateEmptyFrame(kOddWidth, kOddHeight, kOddWidth, kHalfOddWidth,
	kHalfOddWidth);
	ContinuouslyDownscalesByHalfDimensionsAndBackUp();
	}

	void QualityScalerTest::DoesNotDownscaleFrameDimensions(int width, int height) {
	input_frame_.CreateEmptyFrame(width, height, width, (width + 1) / 2,
	(width + 1) / 2);

	for (int i = 0; i < kFramerate * kNumSeconds; ++i) {
	qs_.ReportDroppedFrame();
	qs_.OnEncodeFrame(input_frame_);
	ASSERT_EQ(input_frame_.width(), qs_.GetScaledResolution().width)
	<< "Unexpected scale of minimal-size frame.";
	}
	}

	TEST_F(QualityScalerTest, DoesNotDownscaleFrom1PxWidth) {
	DoesNotDownscaleFrameDimensions(1, kHeight);
	}

	TEST_F(QualityScalerTest, DoesNotDownscaleFrom1PxHeight) {
	DoesNotDownscaleFrameDimensions(kWidth, 1);
	}

	TEST_F(QualityScalerTest, DoesNotDownscaleFrom1Px) {
	DoesNotDownscaleFrameDimensions(1, 1);
	}

	TEST_F(QualityScalerTest, DoesNotDownscaleBelow2xDefaultMinDimensionsWidth) {
	DoesNotDownscaleFrameDimensions(
	2 * kMinDownscaleDimension - 1, 1000);
	}

	TEST_F(QualityScalerTest, DoesNotDownscaleBelow2xDefaultMinDimensionsHeight) {
	DoesNotDownscaleFrameDimensions(
	1000, 2 * kMinDownscaleDimension - 1);
	}

	TEST_F(QualityScalerTest, DownscaleToVgaOnLowInitialBitrate) {
	static const int kWidth720p = 1280;
	static const int kHeight720p = 720;
	static const int kInitialBitrateKbps = 300;
	input_frame_.CreateEmptyFrame(kWidth720p, kHeight720p, kWidth720p,
	kWidth720p / 2, kWidth720p / 2);
	qs_.Init(kLowQpThreshold, kDisabledBadQpThreshold, kInitialBitrateKbps,
	kWidth720p, kHeight720p, kFramerate);
	qs_.OnEncodeFrame(input_frame_);
	int init_width = qs_.GetScaledResolution().width;
	int init_height = qs_.GetScaledResolution().height;
	EXPECT_EQ(640, init_width);
	EXPECT_EQ(360, init_height);
	}

	TEST_F(QualityScalerTest, DownscaleToQvgaOnLowerInitialBitrate) {
	static const int kWidth720p = 1280;
	static const int kHeight720p = 720;
	static const int kInitialBitrateKbps = 200;
	input_frame_.CreateEmptyFrame(kWidth720p, kHeight720p, kWidth720p,
	kWidth720p / 2, kWidth720p / 2);
	qs_.Init(kLowQpThreshold, kDisabledBadQpThreshold, kInitialBitrateKbps,
	kWidth720p, kHeight720p, kFramerate);
	qs_.OnEncodeFrame(input_frame_);
	int init_width = qs_.GetScaledResolution().width;
	int init_height = qs_.GetScaledResolution().height;
	EXPECT_EQ(320, init_width);
	EXPECT_EQ(180, init_height);
	}

	TEST_F(QualityScalerTest, DownscaleAfterMeasuredSecondsThenSlowerBackUp) {
	qs_.Init(kLowQpThreshold, kHighQp, 0, kWidth, kHeight, kFramerate);
	qs_.OnEncodeFrame(input_frame_);
	QualityScaler::Resolution initial_res = qs_.GetScaledResolution();

	// Should not downscale if less than kMeasureSecondsDownscale seconds passed.
	for (int i = 0; i < kFramerate * kMeasureSecondsDownscale - 1; ++i) {
	qs_.ReportQP(kHighQp + 1);
	qs_.OnEncodeFrame(input_frame_);
	}
	EXPECT_EQ(initial_res.width, qs_.GetScaledResolution().width);
	EXPECT_EQ(initial_res.height, qs_.GetScaledResolution().height);

	// Should downscale if more than kMeasureSecondsDownscale seconds passed (add
	// last frame).
	qs_.ReportQP(kHighQp + 1);
	qs_.OnEncodeFrame(input_frame_);
	EXPECT_GT(initial_res.width, qs_.GetScaledResolution().width);
	EXPECT_GT(initial_res.height, qs_.GetScaledResolution().height);

	// Should not upscale if less than kMeasureSecondsUpscale seconds passed since
	// we saw issues initially (have already gone down).
	for (int i = 0; i < kFramerate * kMeasureSecondsUpscale - 1; ++i) {
	qs_.ReportQP(kLowQp);
	qs_.OnEncodeFrame(input_frame_);
	}
	EXPECT_GT(initial_res.width, qs_.GetScaledResolution().width);
	EXPECT_GT(initial_res.height, qs_.GetScaledResolution().height);

	// Should upscale (back to initial) if kMeasureSecondsUpscale seconds passed
	// (add last frame).
	qs_.ReportQP(kLowQp);
	qs_.OnEncodeFrame(input_frame_);
	EXPECT_EQ(initial_res.width, qs_.GetScaledResolution().width);
	EXPECT_EQ(initial_res.height, qs_.GetScaledResolution().height);
	}

	TEST_F(QualityScalerTest, UpscaleQuicklyInitiallyAfterMeasuredSeconds) {
	qs_.Init(kLowQpThreshold, kHighQp, kLowInitialBitrateKbps, kWidth, kHeight,
	kFramerate);
	qs_.OnEncodeFrame(input_frame_);
	QualityScaler::Resolution initial_res = qs_.GetScaledResolution();

	// Should not upscale if less than kMeasureSecondsFastUpscale seconds passed.
	for (int i = 0; i < kFramerate * kMeasureSecondsFastUpscale - 1; ++i) {
	qs_.ReportQP(kLowQp);
	qs_.OnEncodeFrame(input_frame_);
	}
	EXPECT_EQ(initial_res.width, qs_.GetScaledResolution().width);
	EXPECT_EQ(initial_res.height, qs_.GetScaledResolution().height);

	// Should upscale if kMeasureSecondsFastUpscale seconds passed (add last
	// frame).
	qs_.ReportQP(kLowQp);
	qs_.OnEncodeFrame(input_frame_);
	EXPECT_LT(initial_res.width, qs_.GetScaledResolution().width);
	EXPECT_LT(initial_res.height, qs_.GetScaledResolution().height);
	}

	void QualityScalerTest::DownscaleEndsAt(int input_width,
	int input_height,
	int end_width,
	int end_height) {
	// Create a frame with 2x expected end width/height to verify that we can
	// scale down to expected end width/height.
	input_frame_.CreateEmptyFrame(input_width, input_height, input_width,
	(input_width + 1) / 2, (input_width + 1) / 2);

	int last_width = input_width;
	int last_height = input_height;
	// Drop all frames to force-trigger downscaling.
	while (true) {
	TriggerScale(kScaleDown);
	QualityScaler::Resolution res = qs_.GetScaledResolution();
	if (last_width == res.width) {
	EXPECT_EQ(last_height, res.height);
	EXPECT_EQ(end_width, res.width);
	EXPECT_EQ(end_height, res.height);
	break;
	}
	last_width = res.width;
	last_height = res.height;
	}
	}

	TEST_F(QualityScalerTest, DownscalesTo320x180) {
	DownscaleEndsAt(640, 360, 320, 180);
	}

	TEST_F(QualityScalerTest, DownscalesTo180x320) {
	DownscaleEndsAt(360, 640, 180, 320);
	}

	TEST_F(QualityScalerTest, DownscalesFrom1280x720To320x180) {
	DownscaleEndsAt(1280, 720, 320, 180);
	}

	TEST_F(QualityScalerTest, DoesntDownscaleInitialQvga) {
	DownscaleEndsAt(320, 180, 320, 180);
	}

	} // namespace webrtc