webrtc/call/bitrate_allocator_unittest.cc - src - Git at Google

 /*
  *  Copyright (c) 2012 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 <algorithm>
 #include <memory>
 #include <vector>

 #include "testing/gtest/include/gtest/gtest.h"
 #include "webrtc/call/bitrate_allocator.h"
 #include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"

 namespace webrtc {

 class TestBitrateObserver : public BitrateAllocatorObserver {
  public:
   TestBitrateObserver()
       : last_bitrate_bps_(0), last_fraction_loss_(0), last_rtt_ms_(0) {}

   void OnBitrateUpdated(uint32_t bitrate_bps,
                         uint8_t fraction_loss,
                         int64_t rtt) override {
     last_bitrate_bps_ = bitrate_bps;
     last_fraction_loss_ = fraction_loss;
     last_rtt_ms_ = rtt;
   }
   uint32_t last_bitrate_bps_;
   uint8_t last_fraction_loss_;
   int64_t last_rtt_ms_;
 };

 class BitrateAllocatorTest : public ::testing::Test {
  protected:
   BitrateAllocatorTest() : allocator_(new BitrateAllocator()) {
     allocator_->OnNetworkChanged(300000u, 0, 0);
   }
   ~BitrateAllocatorTest() {}

   std::unique_ptr<BitrateAllocator> allocator_;
 };

 TEST_F(BitrateAllocatorTest, UpdatingBitrateObserver) {
   TestBitrateObserver bitrate_observer;
   int start_bitrate =
       allocator_->AddObserver(&bitrate_observer, 100000, 1500000, true);
   EXPECT_EQ(300000, start_bitrate);
   allocator_->OnNetworkChanged(200000, 0, 0);
   EXPECT_EQ(200000u, bitrate_observer.last_bitrate_bps_);

   // TODO(pbos): Expect capping to 1.5M instead of 3M when not boosting the max
   // bitrate for FEC/retransmissions (see todo in BitrateAllocator).
   allocator_->OnNetworkChanged(4000000, 0, 0);
   EXPECT_EQ(3000000u, bitrate_observer.last_bitrate_bps_);
   start_bitrate =
       allocator_->AddObserver(&bitrate_observer, 100000, 4000000, true);
   EXPECT_EQ(4000000, start_bitrate);

   start_bitrate =
       allocator_->AddObserver(&bitrate_observer, 100000, 1500000, true);
   EXPECT_EQ(3000000, start_bitrate);
   EXPECT_EQ(3000000u, bitrate_observer.last_bitrate_bps_);
   allocator_->OnNetworkChanged(1500000, 0, 0);
   EXPECT_EQ(1500000u, bitrate_observer.last_bitrate_bps_);
 }

 TEST_F(BitrateAllocatorTest, TwoBitrateObserversOneRtcpObserver) {
   TestBitrateObserver bitrate_observer_1;
   TestBitrateObserver bitrate_observer_2;
   int start_bitrate =
       allocator_->AddObserver(&bitrate_observer_1, 100000, 300000, true);
   EXPECT_EQ(300000, start_bitrate);
   start_bitrate =
       allocator_->AddObserver(&bitrate_observer_2, 200000, 300000, true);
   EXPECT_EQ(200000, start_bitrate);

   // Test too low start bitrate, hence lower than sum of min. Min bitrates will
   // be allocated to all observers.
   allocator_->OnNetworkChanged(200000, 0, 50);
   EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(0, bitrate_observer_1.last_fraction_loss_);
   EXPECT_EQ(50, bitrate_observer_1.last_rtt_ms_);
   EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_bps_);
   EXPECT_EQ(0, bitrate_observer_2.last_fraction_loss_);
   EXPECT_EQ(50, bitrate_observer_2.last_rtt_ms_);

   // Test a bitrate which should be distributed equally.
   allocator_->OnNetworkChanged(500000, 0, 50);
   const uint32_t kBitrateToShare = 500000 - 200000 - 100000;
   EXPECT_EQ(100000u + kBitrateToShare / 2,
             bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(200000u + kBitrateToShare / 2,
             bitrate_observer_2.last_bitrate_bps_);

   // Limited by 2x max bitrates since we leave room for FEC and retransmissions.
   allocator_->OnNetworkChanged(1500000, 0, 50);
   EXPECT_EQ(600000u, bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(600000u, bitrate_observer_2.last_bitrate_bps_);

   // Verify that if the bandwidth estimate is set to zero, the allocated rate is
   // zero.
   allocator_->OnNetworkChanged(0, 0, 50);
   EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_bps_);
 }

 class BitrateAllocatorTestNoEnforceMin : public ::testing::Test {
  protected:
   BitrateAllocatorTestNoEnforceMin() : allocator_(new BitrateAllocator()) {
     allocator_->OnNetworkChanged(300000u, 0, 0);
   }
   ~BitrateAllocatorTestNoEnforceMin() {}

   std::unique_ptr<BitrateAllocator> allocator_;
 };

 // The following three tests verify enforcing a minimum bitrate works as
 // intended.
 TEST_F(BitrateAllocatorTestNoEnforceMin, OneBitrateObserver) {
   TestBitrateObserver bitrate_observer_1;
   int start_bitrate =
       allocator_->AddObserver(&bitrate_observer_1, 100000, 400000, false);
   EXPECT_EQ(300000, start_bitrate);

   // High BWE.
   allocator_->OnNetworkChanged(150000, 0, 0);
   EXPECT_EQ(150000u, bitrate_observer_1.last_bitrate_bps_);

   // Low BWE.
   allocator_->OnNetworkChanged(10000, 0, 0);
   EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);

   allocator_->RemoveObserver(&bitrate_observer_1);
 }

 TEST_F(BitrateAllocatorTestNoEnforceMin, ThreeBitrateObservers) {
   TestBitrateObserver bitrate_observer_1;
   TestBitrateObserver bitrate_observer_2;
   TestBitrateObserver bitrate_observer_3;
   // Set up the observers with min bitrates at 100000, 200000, and 300000.
   int start_bitrate =
       allocator_->AddObserver(&bitrate_observer_1, 100000, 400000, false);
   EXPECT_EQ(300000, start_bitrate);

   start_bitrate =
       allocator_->AddObserver(&bitrate_observer_2, 200000, 400000, false);
   EXPECT_EQ(200000, start_bitrate);
   EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);

   start_bitrate =
       allocator_->AddObserver(&bitrate_observer_3, 300000, 400000, false);
   EXPECT_EQ(0, start_bitrate);
   EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_bps_);

   // High BWE. Make sure the controllers get a fair share of the surplus (i.e.,
   // what is left after each controller gets its min rate).
   allocator_->OnNetworkChanged(690000, 0, 0);
   // Verify that each observer gets its min rate (sum of min rates is 600000),
   // and that the remaining 90000 is divided equally among the three.
   uint32_t bitrate_to_share = 690000u - 100000u - 200000u - 300000u;
   EXPECT_EQ(100000u + bitrate_to_share / 3,
             bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(200000u + bitrate_to_share / 3,
             bitrate_observer_2.last_bitrate_bps_);
   EXPECT_EQ(300000u + bitrate_to_share / 3,
             bitrate_observer_3.last_bitrate_bps_);

   // BWE below the sum of observer's min bitrate.
   allocator_->OnNetworkChanged(300000, 0, 0);
   EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);  // Min bitrate.
   EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_bps_);  // Min bitrate.
   EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_bps_);  // Nothing.

   // Increased BWE, but still below the sum of configured min bitrates for all
   // observers and too little for observer 3. 1 and 2 will share the rest.
   allocator_->OnNetworkChanged(500000, 0, 0);
   EXPECT_EQ(200000u, bitrate_observer_1.last_bitrate_bps_);  // Min + split.
   EXPECT_EQ(300000u, bitrate_observer_2.last_bitrate_bps_);  // Min + split.
   EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_bps_);  // Nothing.

   // Below min for all.
   allocator_->OnNetworkChanged(10000, 0, 0);
   EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_bps_);
   EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_bps_);

   // Verify that zero estimated bandwidth, means that that all gets zero,
   // regardless of set min bitrate.
   allocator_->OnNetworkChanged(0, 0, 0);
   EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_bps_);
   EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_bps_);

   allocator_->RemoveObserver(&bitrate_observer_1);
   allocator_->RemoveObserver(&bitrate_observer_2);
   allocator_->RemoveObserver(&bitrate_observer_3);
 }

 TEST_F(BitrateAllocatorTest, ThreeBitrateObserversLowBweEnforceMin) {
   TestBitrateObserver bitrate_observer_1;
   TestBitrateObserver bitrate_observer_2;
   TestBitrateObserver bitrate_observer_3;
   int start_bitrate =
       allocator_->AddObserver(&bitrate_observer_1, 100000, 400000, true);
   EXPECT_EQ(300000, start_bitrate);

   start_bitrate =
       allocator_->AddObserver(&bitrate_observer_2, 200000, 400000, true);
   EXPECT_EQ(200000, start_bitrate);
   EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);

   start_bitrate =
       allocator_->AddObserver(&bitrate_observer_3, 300000, 400000, true);
   EXPECT_EQ(300000, start_bitrate);
   EXPECT_EQ(100000, static_cast<int>(bitrate_observer_1.last_bitrate_bps_));
   EXPECT_EQ(200000, static_cast<int>(bitrate_observer_2.last_bitrate_bps_));

   // Low BWE. Verify that all observers still get their respective min bitrate.
   allocator_->OnNetworkChanged(1000, 0, 0);
   EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);  // Min cap.
   EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_bps_);  // Min cap.
   EXPECT_EQ(300000u, bitrate_observer_3.last_bitrate_bps_);  // Min cap.

   allocator_->RemoveObserver(&bitrate_observer_1);
   allocator_->RemoveObserver(&bitrate_observer_2);
   allocator_->RemoveObserver(&bitrate_observer_3);
 }

 TEST_F(BitrateAllocatorTest, AddObserverWhileNetworkDown) {
   TestBitrateObserver bitrate_observer_1;
   int start_bitrate =
       allocator_->AddObserver(&bitrate_observer_1, 50000, 400000, true);
   EXPECT_EQ(300000, start_bitrate);

   // Set network down, ie, no available bitrate.
   allocator_->OnNetworkChanged(0, 0, 0);

   EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);

   TestBitrateObserver bitrate_observer_2;
   start_bitrate =
       allocator_->AddObserver(&bitrate_observer_2, 50000, 400000, true);

   // Expect the start_bitrate to be set as if the network was still up but that
   // the new observer have been notified that the network is down.
   EXPECT_EQ(300000 / 2, start_bitrate);
   EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_bps_);

   // Set network back up.
   allocator_->OnNetworkChanged(1500000, 0, 50);
   EXPECT_EQ(750000u, bitrate_observer_1.last_bitrate_bps_);
   EXPECT_EQ(750000u, bitrate_observer_2.last_bitrate_bps_);
 }

 TEST_F(BitrateAllocatorTest, MixedEnforecedConfigs) {
   TestBitrateObserver enforced_observer;
   int start_bitrate =
       allocator_->AddObserver(&enforced_observer, 6000, 30000, true);
   EXPECT_EQ(60000, start_bitrate);

   TestBitrateObserver not_enforced_observer;
   start_bitrate =
       allocator_->AddObserver(&not_enforced_observer, 30000, 2500000, false);
   EXPECT_EQ(270000, start_bitrate);
   EXPECT_EQ(30000u, enforced_observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(36000, 0, 50);
   EXPECT_EQ(6000u, enforced_observer.last_bitrate_bps_);
   EXPECT_EQ(30000u, not_enforced_observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(35000, 0, 50);
   EXPECT_EQ(30000u, enforced_observer.last_bitrate_bps_);
   EXPECT_EQ(0u, not_enforced_observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(5000, 0, 50);
   EXPECT_EQ(6000u, enforced_observer.last_bitrate_bps_);
   EXPECT_EQ(0u, not_enforced_observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(36000, 0, 50);
   EXPECT_EQ(30000u, enforced_observer.last_bitrate_bps_);
   EXPECT_EQ(0u, not_enforced_observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(55000, 0, 50);
   EXPECT_EQ(30000u, enforced_observer.last_bitrate_bps_);
   EXPECT_EQ(0u, not_enforced_observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(56000, 0, 50);
   EXPECT_EQ(6000u, enforced_observer.last_bitrate_bps_);
   EXPECT_EQ(50000u, not_enforced_observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(56000, 0, 50);
   EXPECT_EQ(16000u, enforced_observer.last_bitrate_bps_);
   EXPECT_EQ(40000u, not_enforced_observer.last_bitrate_bps_);

   allocator_->RemoveObserver(&enforced_observer);
   allocator_->RemoveObserver(&not_enforced_observer);
 }

 TEST_F(BitrateAllocatorTest, AvoidToggleAbsolute) {
   TestBitrateObserver observer;
   int start_bitrate =
       allocator_->AddObserver(&observer, 30000, 300000, false);
   EXPECT_EQ(300000, start_bitrate);

   allocator_->OnNetworkChanged(30000, 0, 50);
   EXPECT_EQ(30000u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(20000, 0, 50);
   EXPECT_EQ(0u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(30000, 0, 50);
   EXPECT_EQ(0u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(49000, 0, 50);
   EXPECT_EQ(0u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(50000, 0, 50);
   EXPECT_EQ(50000u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(30000, 0, 50);
   EXPECT_EQ(30000u, observer.last_bitrate_bps_);

   allocator_->RemoveObserver(&observer);
 }

 TEST_F(BitrateAllocatorTest, AvoidTogglePercent) {
   TestBitrateObserver observer;
   int start_bitrate =
       allocator_->AddObserver(&observer, 300000, 600000, false);
   EXPECT_EQ(300000, start_bitrate);

   allocator_->OnNetworkChanged(300000, 0, 50);
   EXPECT_EQ(300000u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(200000, 0, 50);
   EXPECT_EQ(0u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(300000, 0, 50);
   EXPECT_EQ(0u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(329000, 0, 50);
   EXPECT_EQ(0u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(330000, 0, 50);
   EXPECT_EQ(330000u, observer.last_bitrate_bps_);

   allocator_->OnNetworkChanged(300000, 0, 50);
   EXPECT_EQ(300000u, observer.last_bitrate_bps_);

   allocator_->RemoveObserver(&observer);
 }

 }  // namespace webrtc
	/*
	* Copyright (c) 2012 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 <algorithm>
	#include <memory>
	#include <vector>

	#include "testing/gtest/include/gtest/gtest.h"
	#include "webrtc/call/bitrate_allocator.h"
	#include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"

	namespace webrtc {

	class TestBitrateObserver : public BitrateAllocatorObserver {
	public:
	TestBitrateObserver()
	: last_bitrate_bps_(0), last_fraction_loss_(0), last_rtt_ms_(0) {}

	void OnBitrateUpdated(uint32_t bitrate_bps,
	uint8_t fraction_loss,
	int64_t rtt) override {
	last_bitrate_bps_ = bitrate_bps;
	last_fraction_loss_ = fraction_loss;
	last_rtt_ms_ = rtt;
	}
	uint32_t last_bitrate_bps_;
	uint8_t last_fraction_loss_;
	int64_t last_rtt_ms_;
	};

	class BitrateAllocatorTest : public ::testing::Test {
	protected:
	BitrateAllocatorTest() : allocator_(new BitrateAllocator()) {
	allocator_->OnNetworkChanged(300000u, 0, 0);
	}
	~BitrateAllocatorTest() {}

	std::unique_ptr<BitrateAllocator> allocator_;
	};

	TEST_F(BitrateAllocatorTest, UpdatingBitrateObserver) {
	TestBitrateObserver bitrate_observer;
	int start_bitrate =
	allocator_->AddObserver(&bitrate_observer, 100000, 1500000, true);
	EXPECT_EQ(300000, start_bitrate);
	allocator_->OnNetworkChanged(200000, 0, 0);
	EXPECT_EQ(200000u, bitrate_observer.last_bitrate_bps_);

	// TODO(pbos): Expect capping to 1.5M instead of 3M when not boosting the max
	// bitrate for FEC/retransmissions (see todo in BitrateAllocator).
	allocator_->OnNetworkChanged(4000000, 0, 0);
	EXPECT_EQ(3000000u, bitrate_observer.last_bitrate_bps_);
	start_bitrate =
	allocator_->AddObserver(&bitrate_observer, 100000, 4000000, true);
	EXPECT_EQ(4000000, start_bitrate);

	start_bitrate =
	allocator_->AddObserver(&bitrate_observer, 100000, 1500000, true);
	EXPECT_EQ(3000000, start_bitrate);
	EXPECT_EQ(3000000u, bitrate_observer.last_bitrate_bps_);
	allocator_->OnNetworkChanged(1500000, 0, 0);
	EXPECT_EQ(1500000u, bitrate_observer.last_bitrate_bps_);
	}

	TEST_F(BitrateAllocatorTest, TwoBitrateObserversOneRtcpObserver) {
	TestBitrateObserver bitrate_observer_1;
	TestBitrateObserver bitrate_observer_2;
	int start_bitrate =
	allocator_->AddObserver(&bitrate_observer_1, 100000, 300000, true);
	EXPECT_EQ(300000, start_bitrate);
	start_bitrate =
	allocator_->AddObserver(&bitrate_observer_2, 200000, 300000, true);
	EXPECT_EQ(200000, start_bitrate);

	// Test too low start bitrate, hence lower than sum of min. Min bitrates will
	// be allocated to all observers.
	allocator_->OnNetworkChanged(200000, 0, 50);
	EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(0, bitrate_observer_1.last_fraction_loss_);
	EXPECT_EQ(50, bitrate_observer_1.last_rtt_ms_);
	EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_bps_);
	EXPECT_EQ(0, bitrate_observer_2.last_fraction_loss_);
	EXPECT_EQ(50, bitrate_observer_2.last_rtt_ms_);

	// Test a bitrate which should be distributed equally.
	allocator_->OnNetworkChanged(500000, 0, 50);
	const uint32_t kBitrateToShare = 500000 - 200000 - 100000;
	EXPECT_EQ(100000u + kBitrateToShare / 2,
	bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(200000u + kBitrateToShare / 2,
	bitrate_observer_2.last_bitrate_bps_);

	// Limited by 2x max bitrates since we leave room for FEC and retransmissions.
	allocator_->OnNetworkChanged(1500000, 0, 50);
	EXPECT_EQ(600000u, bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(600000u, bitrate_observer_2.last_bitrate_bps_);

	// Verify that if the bandwidth estimate is set to zero, the allocated rate is
	// zero.
	allocator_->OnNetworkChanged(0, 0, 50);
	EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_bps_);
	}

	class BitrateAllocatorTestNoEnforceMin : public ::testing::Test {
	protected:
	BitrateAllocatorTestNoEnforceMin() : allocator_(new BitrateAllocator()) {
	allocator_->OnNetworkChanged(300000u, 0, 0);
	}
	~BitrateAllocatorTestNoEnforceMin() {}

	std::unique_ptr<BitrateAllocator> allocator_;
	};

	// The following three tests verify enforcing a minimum bitrate works as
	// intended.
	TEST_F(BitrateAllocatorTestNoEnforceMin, OneBitrateObserver) {
	TestBitrateObserver bitrate_observer_1;
	int start_bitrate =
	allocator_->AddObserver(&bitrate_observer_1, 100000, 400000, false);
	EXPECT_EQ(300000, start_bitrate);

	// High BWE.
	allocator_->OnNetworkChanged(150000, 0, 0);
	EXPECT_EQ(150000u, bitrate_observer_1.last_bitrate_bps_);

	// Low BWE.
	allocator_->OnNetworkChanged(10000, 0, 0);
	EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);

	allocator_->RemoveObserver(&bitrate_observer_1);
	}

	TEST_F(BitrateAllocatorTestNoEnforceMin, ThreeBitrateObservers) {
	TestBitrateObserver bitrate_observer_1;
	TestBitrateObserver bitrate_observer_2;
	TestBitrateObserver bitrate_observer_3;
	// Set up the observers with min bitrates at 100000, 200000, and 300000.
	int start_bitrate =
	allocator_->AddObserver(&bitrate_observer_1, 100000, 400000, false);
	EXPECT_EQ(300000, start_bitrate);

	start_bitrate =
	allocator_->AddObserver(&bitrate_observer_2, 200000, 400000, false);
	EXPECT_EQ(200000, start_bitrate);
	EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);

	start_bitrate =
	allocator_->AddObserver(&bitrate_observer_3, 300000, 400000, false);
	EXPECT_EQ(0, start_bitrate);
	EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_bps_);

	// High BWE. Make sure the controllers get a fair share of the surplus (i.e.,
	// what is left after each controller gets its min rate).
	allocator_->OnNetworkChanged(690000, 0, 0);
	// Verify that each observer gets its min rate (sum of min rates is 600000),
	// and that the remaining 90000 is divided equally among the three.
	uint32_t bitrate_to_share = 690000u - 100000u - 200000u - 300000u;
	EXPECT_EQ(100000u + bitrate_to_share / 3,
	bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(200000u + bitrate_to_share / 3,
	bitrate_observer_2.last_bitrate_bps_);
	EXPECT_EQ(300000u + bitrate_to_share / 3,
	bitrate_observer_3.last_bitrate_bps_);

	// BWE below the sum of observer's min bitrate.
	allocator_->OnNetworkChanged(300000, 0, 0);
	EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_); // Min bitrate.
	EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_bps_); // Min bitrate.
	EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_bps_); // Nothing.

	// Increased BWE, but still below the sum of configured min bitrates for all
	// observers and too little for observer 3. 1 and 2 will share the rest.
	allocator_->OnNetworkChanged(500000, 0, 0);
	EXPECT_EQ(200000u, bitrate_observer_1.last_bitrate_bps_); // Min + split.
	EXPECT_EQ(300000u, bitrate_observer_2.last_bitrate_bps_); // Min + split.
	EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_bps_); // Nothing.

	// Below min for all.
	allocator_->OnNetworkChanged(10000, 0, 0);
	EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_bps_);
	EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_bps_);

	// Verify that zero estimated bandwidth, means that that all gets zero,
	// regardless of set min bitrate.
	allocator_->OnNetworkChanged(0, 0, 0);
	EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_bps_);
	EXPECT_EQ(0u, bitrate_observer_3.last_bitrate_bps_);

	allocator_->RemoveObserver(&bitrate_observer_1);
	allocator_->RemoveObserver(&bitrate_observer_2);
	allocator_->RemoveObserver(&bitrate_observer_3);
	}

	TEST_F(BitrateAllocatorTest, ThreeBitrateObserversLowBweEnforceMin) {
	TestBitrateObserver bitrate_observer_1;
	TestBitrateObserver bitrate_observer_2;
	TestBitrateObserver bitrate_observer_3;
	int start_bitrate =
	allocator_->AddObserver(&bitrate_observer_1, 100000, 400000, true);
	EXPECT_EQ(300000, start_bitrate);

	start_bitrate =
	allocator_->AddObserver(&bitrate_observer_2, 200000, 400000, true);
	EXPECT_EQ(200000, start_bitrate);
	EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_);

	start_bitrate =
	allocator_->AddObserver(&bitrate_observer_3, 300000, 400000, true);
	EXPECT_EQ(300000, start_bitrate);
	EXPECT_EQ(100000, static_cast<int>(bitrate_observer_1.last_bitrate_bps_));
	EXPECT_EQ(200000, static_cast<int>(bitrate_observer_2.last_bitrate_bps_));

	// Low BWE. Verify that all observers still get their respective min bitrate.
	allocator_->OnNetworkChanged(1000, 0, 0);
	EXPECT_EQ(100000u, bitrate_observer_1.last_bitrate_bps_); // Min cap.
	EXPECT_EQ(200000u, bitrate_observer_2.last_bitrate_bps_); // Min cap.
	EXPECT_EQ(300000u, bitrate_observer_3.last_bitrate_bps_); // Min cap.

	allocator_->RemoveObserver(&bitrate_observer_1);
	allocator_->RemoveObserver(&bitrate_observer_2);
	allocator_->RemoveObserver(&bitrate_observer_3);
	}

	TEST_F(BitrateAllocatorTest, AddObserverWhileNetworkDown) {
	TestBitrateObserver bitrate_observer_1;
	int start_bitrate =
	allocator_->AddObserver(&bitrate_observer_1, 50000, 400000, true);
	EXPECT_EQ(300000, start_bitrate);

	// Set network down, ie, no available bitrate.
	allocator_->OnNetworkChanged(0, 0, 0);

	EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);

	TestBitrateObserver bitrate_observer_2;
	start_bitrate =
	allocator_->AddObserver(&bitrate_observer_2, 50000, 400000, true);

	// Expect the start_bitrate to be set as if the network was still up but that
	// the new observer have been notified that the network is down.
	EXPECT_EQ(300000 / 2, start_bitrate);
	EXPECT_EQ(0u, bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(0u, bitrate_observer_2.last_bitrate_bps_);

	// Set network back up.
	allocator_->OnNetworkChanged(1500000, 0, 50);
	EXPECT_EQ(750000u, bitrate_observer_1.last_bitrate_bps_);
	EXPECT_EQ(750000u, bitrate_observer_2.last_bitrate_bps_);
	}

	TEST_F(BitrateAllocatorTest, MixedEnforecedConfigs) {
	TestBitrateObserver enforced_observer;
	int start_bitrate =
	allocator_->AddObserver(&enforced_observer, 6000, 30000, true);
	EXPECT_EQ(60000, start_bitrate);

	TestBitrateObserver not_enforced_observer;
	start_bitrate =
	allocator_->AddObserver(&not_enforced_observer, 30000, 2500000, false);
	EXPECT_EQ(270000, start_bitrate);
	EXPECT_EQ(30000u, enforced_observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(36000, 0, 50);
	EXPECT_EQ(6000u, enforced_observer.last_bitrate_bps_);
	EXPECT_EQ(30000u, not_enforced_observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(35000, 0, 50);
	EXPECT_EQ(30000u, enforced_observer.last_bitrate_bps_);
	EXPECT_EQ(0u, not_enforced_observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(5000, 0, 50);
	EXPECT_EQ(6000u, enforced_observer.last_bitrate_bps_);
	EXPECT_EQ(0u, not_enforced_observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(36000, 0, 50);
	EXPECT_EQ(30000u, enforced_observer.last_bitrate_bps_);
	EXPECT_EQ(0u, not_enforced_observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(55000, 0, 50);
	EXPECT_EQ(30000u, enforced_observer.last_bitrate_bps_);
	EXPECT_EQ(0u, not_enforced_observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(56000, 0, 50);
	EXPECT_EQ(6000u, enforced_observer.last_bitrate_bps_);
	EXPECT_EQ(50000u, not_enforced_observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(56000, 0, 50);
	EXPECT_EQ(16000u, enforced_observer.last_bitrate_bps_);
	EXPECT_EQ(40000u, not_enforced_observer.last_bitrate_bps_);

	allocator_->RemoveObserver(&enforced_observer);
	allocator_->RemoveObserver(&not_enforced_observer);
	}

	TEST_F(BitrateAllocatorTest, AvoidToggleAbsolute) {
	TestBitrateObserver observer;
	int start_bitrate =
	allocator_->AddObserver(&observer, 30000, 300000, false);
	EXPECT_EQ(300000, start_bitrate);

	allocator_->OnNetworkChanged(30000, 0, 50);
	EXPECT_EQ(30000u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(20000, 0, 50);
	EXPECT_EQ(0u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(30000, 0, 50);
	EXPECT_EQ(0u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(49000, 0, 50);
	EXPECT_EQ(0u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(50000, 0, 50);
	EXPECT_EQ(50000u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(30000, 0, 50);
	EXPECT_EQ(30000u, observer.last_bitrate_bps_);

	allocator_->RemoveObserver(&observer);
	}

	TEST_F(BitrateAllocatorTest, AvoidTogglePercent) {
	TestBitrateObserver observer;
	int start_bitrate =
	allocator_->AddObserver(&observer, 300000, 600000, false);
	EXPECT_EQ(300000, start_bitrate);

	allocator_->OnNetworkChanged(300000, 0, 50);
	EXPECT_EQ(300000u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(200000, 0, 50);
	EXPECT_EQ(0u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(300000, 0, 50);
	EXPECT_EQ(0u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(329000, 0, 50);
	EXPECT_EQ(0u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(330000, 0, 50);
	EXPECT_EQ(330000u, observer.last_bitrate_bps_);

	allocator_->OnNetworkChanged(300000, 0, 50);
	EXPECT_EQ(300000u, observer.last_bitrate_bps_);

	allocator_->RemoveObserver(&observer);
	}

	} // namespace webrtc