modules/audio_coding/audio_network_adaptor/fec_controller_rplr_based_unittest.cc - mirrors/cros/chromiumos/third_party/webrtc-apm - Git at Google

 /*
  *  Copyright (c) 2017 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 <random>
 #include <utility>

 #include "modules/audio_coding/audio_network_adaptor/fec_controller_rplr_based.h"
 #include "test/gtest.h"

 namespace webrtc {

 namespace {

 // The test uses the following settings:
 //
 // recoverable ^
 // packet-loss |   |  |
 //             |  A| C|   FEC
 //             |    \  \   ON
 //             | FEC \ D\_______
 //             | OFF B\_________
 //             |-----------------> bandwidth
 //
 // A : (kDisablingBandwidthLow, kDisablingRecoverablePacketLossAtLowBw)
 // B : (kDisablingBandwidthHigh, kDisablingRecoverablePacketLossAtHighBw)
 // C : (kEnablingBandwidthLow, kEnablingRecoverablePacketLossAtLowBw)
 // D : (kEnablingBandwidthHigh, kEnablingRecoverablePacketLossAtHighBw)

 constexpr int kDisablingBandwidthLow = 15000;
 constexpr float kDisablingRecoverablePacketLossAtLowBw = 0.08f;
 constexpr int kDisablingBandwidthHigh = 64000;
 constexpr float kDisablingRecoverablePacketLossAtHighBw = 0.01f;
 constexpr int kEnablingBandwidthLow = 17000;
 constexpr float kEnablingRecoverablePacketLossAtLowBw = 0.1f;
 constexpr int kEnablingBandwidthHigh = 64000;
 constexpr float kEnablingRecoverablePacketLossAtHighBw = 0.05f;

 constexpr float kEpsilon = 1e-5f;

 absl::optional<float> GetRandomProbabilityOrUnknown() {
   std::random_device rd;
   std::mt19937 generator(rd());
   std::uniform_real_distribution<> distribution(0, 1);

   return (distribution(generator) < 0.2)
              ? absl::nullopt
              : absl::optional<float>(distribution(generator));
 }

 std::unique_ptr<FecControllerRplrBased> CreateFecControllerRplrBased(
     bool initial_fec_enabled) {
   return std::unique_ptr<FecControllerRplrBased>(
       new FecControllerRplrBased(FecControllerRplrBased::Config(
           initial_fec_enabled,
           ThresholdCurve(
               kEnablingBandwidthLow, kEnablingRecoverablePacketLossAtLowBw,
               kEnablingBandwidthHigh, kEnablingRecoverablePacketLossAtHighBw),
           ThresholdCurve(kDisablingBandwidthLow,
                          kDisablingRecoverablePacketLossAtLowBw,
                          kDisablingBandwidthHigh,
                          kDisablingRecoverablePacketLossAtHighBw))));
 }

 void UpdateNetworkMetrics(
     FecControllerRplrBased* controller,
     const absl::optional<int>& uplink_bandwidth_bps,
     const absl::optional<float>& uplink_packet_loss,
     const absl::optional<float>& uplink_recoveralbe_packet_loss) {
   // UpdateNetworkMetrics can accept multiple network metric updates at once.
   // However, currently, the most used case is to update one metric at a time.
   // To reflect this fact, we separate the calls.
   if (uplink_bandwidth_bps) {
     Controller::NetworkMetrics network_metrics;
     network_metrics.uplink_bandwidth_bps = uplink_bandwidth_bps;
     controller->UpdateNetworkMetrics(network_metrics);
   }
   if (uplink_packet_loss) {
     Controller::NetworkMetrics network_metrics;
     network_metrics.uplink_packet_loss_fraction = uplink_packet_loss;
     controller->UpdateNetworkMetrics(network_metrics);
   }
   if (uplink_recoveralbe_packet_loss) {
     Controller::NetworkMetrics network_metrics;
     network_metrics.uplink_recoverable_packet_loss_fraction =
         uplink_recoveralbe_packet_loss;
     controller->UpdateNetworkMetrics(network_metrics);
   }
 }

 void UpdateNetworkMetrics(
     FecControllerRplrBased* controller,
     const absl::optional<int>& uplink_bandwidth_bps,
     const absl::optional<float>& uplink_recoveralbe_packet_loss) {
   // FecControllerRplrBased doesn't currently use the PLR (general packet-loss
   // rate) at all. (This might be changed in the future.) The unit-tests will
   // use a random value (including unknown), to show this does not interfere.
   UpdateNetworkMetrics(controller, uplink_bandwidth_bps,
                        GetRandomProbabilityOrUnknown(),
                        uplink_recoveralbe_packet_loss);
 }

 // Checks that the FEC decision and |uplink_packet_loss_fraction| given by
 // |states->controller->MakeDecision| matches |expected_enable_fec| and
 // |expected_uplink_packet_loss_fraction|, respectively.
 void CheckDecision(FecControllerRplrBased* controller,
                    bool expected_enable_fec,
                    float expected_uplink_packet_loss_fraction) {
   AudioEncoderRuntimeConfig config;
   controller->MakeDecision(&config);

   // Less compact than comparing optionals, but yields more readable errors.
   EXPECT_TRUE(config.enable_fec);
   if (config.enable_fec) {
     EXPECT_EQ(expected_enable_fec, *config.enable_fec);
   }
   EXPECT_TRUE(config.uplink_packet_loss_fraction);
   if (config.uplink_packet_loss_fraction) {
     EXPECT_EQ(expected_uplink_packet_loss_fraction,
               *config.uplink_packet_loss_fraction);
   }
 }

 }  // namespace

 TEST(FecControllerRplrBasedTest, OutputInitValueBeforeAnyInputsAreReceived) {
   for (bool initial_fec_enabled : {false, true}) {
     auto controller = CreateFecControllerRplrBased(initial_fec_enabled);
     CheckDecision(controller.get(), initial_fec_enabled, 0);
   }
 }

 TEST(FecControllerRplrBasedTest, OutputInitValueWhenUplinkBandwidthUnknown) {
   // Regardless of the initial FEC state and the recoverable-packet-loss
   // rate, the initial FEC state is maintained as long as the BWE is unknown.
   for (bool initial_fec_enabled : {false, true}) {
     for (float recoverable_packet_loss :
          {kDisablingRecoverablePacketLossAtHighBw - kEpsilon,
           kDisablingRecoverablePacketLossAtHighBw,
           kDisablingRecoverablePacketLossAtHighBw + kEpsilon,
           kEnablingRecoverablePacketLossAtHighBw - kEpsilon,
           kEnablingRecoverablePacketLossAtHighBw,
           kEnablingRecoverablePacketLossAtHighBw + kEpsilon}) {
       auto controller = CreateFecControllerRplrBased(initial_fec_enabled);
       UpdateNetworkMetrics(controller.get(), absl::nullopt,
                            recoverable_packet_loss);
       CheckDecision(controller.get(), initial_fec_enabled,
                     recoverable_packet_loss);
     }
   }
 }

 TEST(FecControllerRplrBasedTest,
      OutputInitValueWhenUplinkRecoverablePacketLossFractionUnknown) {
   // Regardless of the initial FEC state and the BWE, the initial FEC state
   // is maintained as long as the recoverable-packet-loss rate is unknown.
   for (bool initial_fec_enabled : {false, true}) {
     for (int bandwidth : {kDisablingBandwidthLow - 1, kDisablingBandwidthLow,
                           kDisablingBandwidthLow + 1, kEnablingBandwidthLow - 1,
                           kEnablingBandwidthLow, kEnablingBandwidthLow + 1}) {
       auto controller = CreateFecControllerRplrBased(initial_fec_enabled);
       UpdateNetworkMetrics(controller.get(), bandwidth, absl::nullopt);
       CheckDecision(controller.get(), initial_fec_enabled, 0.0);
     }
   }
 }

 TEST(FecControllerRplrBasedTest, EnableFecForHighBandwidth) {
   auto controller = CreateFecControllerRplrBased(false);
   UpdateNetworkMetrics(controller.get(), kEnablingBandwidthHigh,
                        kEnablingRecoverablePacketLossAtHighBw);
   CheckDecision(controller.get(), true, kEnablingRecoverablePacketLossAtHighBw);
 }

 TEST(FecControllerRplrBasedTest, UpdateMultipleNetworkMetricsAtOnce) {
   // This test is similar to EnableFecForHighBandwidth. But instead of
   // using ::UpdateNetworkMetrics(...), which calls
   // FecControllerRplrBasedTest::UpdateNetworkMetrics(...) multiple times, we
   // we call it only once. This is to verify that
   // FecControllerRplrBasedTest::UpdateNetworkMetrics(...) can handle multiple
   // network updates at once. This is, however, not a common use case in current
   // audio_network_adaptor_impl.cc.
   auto controller = CreateFecControllerRplrBased(false);
   Controller::NetworkMetrics network_metrics;
   network_metrics.uplink_bandwidth_bps = kEnablingBandwidthHigh;
   network_metrics.uplink_packet_loss_fraction = GetRandomProbabilityOrUnknown();
   network_metrics.uplink_recoverable_packet_loss_fraction =
       kEnablingRecoverablePacketLossAtHighBw;
   controller->UpdateNetworkMetrics(network_metrics);
   CheckDecision(controller.get(), true, kEnablingRecoverablePacketLossAtHighBw);
 }

 TEST(FecControllerRplrBasedTest, MaintainFecOffForHighBandwidth) {
   auto controller = CreateFecControllerRplrBased(false);
   constexpr float kRecoverablePacketLoss =
       kEnablingRecoverablePacketLossAtHighBw * 0.99f;
   UpdateNetworkMetrics(controller.get(), kEnablingBandwidthHigh,
                        kRecoverablePacketLoss);
   CheckDecision(controller.get(), false, kRecoverablePacketLoss);
 }

 TEST(FecControllerRplrBasedTest, EnableFecForMediumBandwidth) {
   auto controller = CreateFecControllerRplrBased(false);
   constexpr float kRecoverablePacketLoss =
       (kEnablingRecoverablePacketLossAtLowBw +
        kEnablingRecoverablePacketLossAtHighBw) /
       2.0;
   UpdateNetworkMetrics(controller.get(),
                        (kEnablingBandwidthHigh + kEnablingBandwidthLow) / 2,
                        kRecoverablePacketLoss);
   CheckDecision(controller.get(), true, kRecoverablePacketLoss);
 }

 TEST(FecControllerRplrBasedTest, MaintainFecOffForMediumBandwidth) {
   auto controller = CreateFecControllerRplrBased(false);
   constexpr float kRecoverablePacketLoss =
       kEnablingRecoverablePacketLossAtLowBw * 0.49f +
       kEnablingRecoverablePacketLossAtHighBw * 0.51f;
   UpdateNetworkMetrics(controller.get(),
                        (kEnablingBandwidthHigh + kEnablingBandwidthLow) / 2,
                        kRecoverablePacketLoss);
   CheckDecision(controller.get(), false, kRecoverablePacketLoss);
 }

 TEST(FecControllerRplrBasedTest, EnableFecForLowBandwidth) {
   auto controller = CreateFecControllerRplrBased(false);
   UpdateNetworkMetrics(controller.get(), kEnablingBandwidthLow,
                        kEnablingRecoverablePacketLossAtLowBw);
   CheckDecision(controller.get(), true, kEnablingRecoverablePacketLossAtLowBw);
 }

 TEST(FecControllerRplrBasedTest, MaintainFecOffForLowBandwidth) {
   auto controller = CreateFecControllerRplrBased(false);
   constexpr float kRecoverablePacketLoss =
       kEnablingRecoverablePacketLossAtLowBw * 0.99f;
   UpdateNetworkMetrics(controller.get(), kEnablingBandwidthLow,
                        kRecoverablePacketLoss);
   CheckDecision(controller.get(), false, kRecoverablePacketLoss);
 }

 TEST(FecControllerRplrBasedTest, MaintainFecOffForVeryLowBandwidth) {
   auto controller = CreateFecControllerRplrBased(false);
   // Below |kEnablingBandwidthLow|, no recoverable packet loss fraction can
   // cause FEC to turn on.
   UpdateNetworkMetrics(controller.get(), kEnablingBandwidthLow - 1, 1.0);
   CheckDecision(controller.get(), false, 1.0);
 }

 TEST(FecControllerRplrBasedTest, DisableFecForHighBandwidth) {
   auto controller = CreateFecControllerRplrBased(true);
   constexpr float kRecoverablePacketLoss =
       kDisablingRecoverablePacketLossAtHighBw - kEpsilon;
   UpdateNetworkMetrics(controller.get(), kDisablingBandwidthHigh,
                        kRecoverablePacketLoss);
   CheckDecision(controller.get(), false, kRecoverablePacketLoss);
 }

 TEST(FecControllerRplrBasedTest, MaintainFecOnForHighBandwidth) {
   // Note: Disabling happens when the value is strictly below the threshold.
   auto controller = CreateFecControllerRplrBased(true);
   UpdateNetworkMetrics(controller.get(), kDisablingBandwidthHigh,
                        kDisablingRecoverablePacketLossAtHighBw);
   CheckDecision(controller.get(), true,
                 kDisablingRecoverablePacketLossAtHighBw);
 }

 TEST(FecControllerRplrBasedTest, DisableFecOnMediumBandwidth) {
   auto controller = CreateFecControllerRplrBased(true);
   constexpr float kRecoverablePacketLoss =
       ((kDisablingRecoverablePacketLossAtLowBw +
         kDisablingRecoverablePacketLossAtHighBw) /
        2.0f) -
       kEpsilon;
   UpdateNetworkMetrics(controller.get(),
                        (kDisablingBandwidthHigh + kDisablingBandwidthLow) / 2,
                        kRecoverablePacketLoss);
   CheckDecision(controller.get(), false, kRecoverablePacketLoss);
 }

 TEST(FecControllerRplrBasedTest, MaintainFecOnForMediumBandwidth) {
   auto controller = CreateFecControllerRplrBased(true);
   constexpr float kRecoverablePacketLoss =
       kDisablingRecoverablePacketLossAtLowBw * 0.51f +
       kDisablingRecoverablePacketLossAtHighBw * 0.49f - kEpsilon;
   UpdateNetworkMetrics(controller.get(),
                        (kEnablingBandwidthHigh + kDisablingBandwidthLow) / 2,
                        kRecoverablePacketLoss);
   CheckDecision(controller.get(), true, kRecoverablePacketLoss);
 }

 TEST(FecControllerRplrBasedTest, DisableFecForLowBandwidth) {
   auto controller = CreateFecControllerRplrBased(true);
   constexpr float kRecoverablePacketLoss =
       kDisablingRecoverablePacketLossAtLowBw - kEpsilon;
   UpdateNetworkMetrics(controller.get(), kDisablingBandwidthLow,
                        kRecoverablePacketLoss);
   CheckDecision(controller.get(), false, kRecoverablePacketLoss);
 }

 TEST(FecControllerRplrBasedTest, DisableFecForVeryLowBandwidth) {
   auto controller = CreateFecControllerRplrBased(true);
   // Below |kEnablingBandwidthLow|, any recoverable packet loss fraction can
   // cause FEC to turn off.
   UpdateNetworkMetrics(controller.get(), kDisablingBandwidthLow - 1, 1.0);
   CheckDecision(controller.get(), false, 1.0);
 }

 TEST(FecControllerRplrBasedTest, CheckBehaviorOnChangingNetworkMetrics) {
   // In this test, we let the network metrics to traverse from 1 to 5.
   //
   // recoverable ^
   // packet-loss | 1 |  |
   //             |   | 2|
   //             |    \  \ 3
   //             |     \4 \_______
   //             |      \_________
   //             |---------5-------> bandwidth

   auto controller = CreateFecControllerRplrBased(true);
   UpdateNetworkMetrics(controller.get(), kDisablingBandwidthLow - 1, 1.0);
   CheckDecision(controller.get(), false, 1.0);

   UpdateNetworkMetrics(controller.get(), kEnablingBandwidthLow,
                        kEnablingRecoverablePacketLossAtLowBw * 0.99f);
   CheckDecision(controller.get(), false,
                 kEnablingRecoverablePacketLossAtLowBw * 0.99f);

   UpdateNetworkMetrics(controller.get(), kEnablingBandwidthHigh,
                        kEnablingRecoverablePacketLossAtHighBw);
   CheckDecision(controller.get(), true, kEnablingRecoverablePacketLossAtHighBw);

   UpdateNetworkMetrics(controller.get(), kDisablingBandwidthHigh,
                        kDisablingRecoverablePacketLossAtHighBw);
   CheckDecision(controller.get(), true,
                 kDisablingRecoverablePacketLossAtHighBw);

   UpdateNetworkMetrics(controller.get(), kDisablingBandwidthHigh + 1, 0.0);
   CheckDecision(controller.get(), false, 0.0);
 }

 TEST(FecControllerRplrBasedTest, CheckBehaviorOnSpecialCurves) {
   // We test a special configuration, where the points to define the FEC
   // enabling/disabling curves are placed like the following, otherwise the test
   // is the same as CheckBehaviorOnChangingNetworkMetrics.
   //
   // recoverable ^
   // packet-loss |   |  |
   //             |   | C|
   //             |   |  |
   //             |   | D|_______
   //             |  A|___B______
   //             |-----------------> bandwidth

   constexpr int kEnablingBandwidthHigh = kEnablingBandwidthLow;
   constexpr float kDisablingRecoverablePacketLossAtLowBw =
       kDisablingRecoverablePacketLossAtHighBw;
   FecControllerRplrBased controller(FecControllerRplrBased::Config(
       true,
       ThresholdCurve(
           kEnablingBandwidthLow, kEnablingRecoverablePacketLossAtLowBw,
           kEnablingBandwidthHigh, kEnablingRecoverablePacketLossAtHighBw),
       ThresholdCurve(
           kDisablingBandwidthLow, kDisablingRecoverablePacketLossAtLowBw,
           kDisablingBandwidthHigh, kDisablingRecoverablePacketLossAtHighBw)));

   UpdateNetworkMetrics(&controller, kDisablingBandwidthLow - 1, 1.0);
   CheckDecision(&controller, false, 1.0);

   UpdateNetworkMetrics(&controller, kEnablingBandwidthLow,
                        kEnablingRecoverablePacketLossAtHighBw * 0.99f);
   CheckDecision(&controller, false,
                 kEnablingRecoverablePacketLossAtHighBw * 0.99f);

   UpdateNetworkMetrics(&controller, kEnablingBandwidthHigh,
                        kEnablingRecoverablePacketLossAtHighBw);
   CheckDecision(&controller, true, kEnablingRecoverablePacketLossAtHighBw);

   UpdateNetworkMetrics(&controller, kDisablingBandwidthHigh,
                        kDisablingRecoverablePacketLossAtHighBw);
   CheckDecision(&controller, true, kDisablingRecoverablePacketLossAtHighBw);

   UpdateNetworkMetrics(&controller, kDisablingBandwidthHigh + 1, 0.0);
   CheckDecision(&controller, false, 0.0);
 }

 TEST(FecControllerRplrBasedTest, SingleThresholdCurveForEnablingAndDisabling) {
   // Note: To avoid numerical errors, keep kRecoverablePacketLossAtLowBw and
   // kRecoverablePacketLossAthighBw as (negative) integer powers of 2.
   // This is mostly relevant for the O3 case.
   constexpr int kBandwidthLow = 10000;
   constexpr float kRecoverablePacketLossAtLowBw = 0.25f;
   constexpr int kBandwidthHigh = 20000;
   constexpr float kRecoverablePacketLossAtHighBw = 0.125f;
   auto curve = ThresholdCurve(kBandwidthLow, kRecoverablePacketLossAtLowBw,
                               kBandwidthHigh, kRecoverablePacketLossAtHighBw);

   // B* stands for "below-curve", O* for "on-curve", and A* for "above-curve".
   //
   //                                            //
   // recoverable ^                              //
   // packet-loss |    |                         //
   //             | B1 O1                        //
   //             |    |                         //
   //             |    O2                        //
   //             |     \ A1                     //
   //             |      \                       //
   //             |       O3   A2                //
   //             |     B2 \                     //
   //             |         \                    //
   //             |          O4--O5----          //
   //             |                              //
   //             |            B3                //
   //             |-----------------> bandwidth  //

   struct NetworkState {
     int bandwidth;
     float recoverable_packet_loss;
   };

   std::vector<NetworkState> below{
       {kBandwidthLow - 1, kRecoverablePacketLossAtLowBw + 0.1f},  // B1
       {(kBandwidthLow + kBandwidthHigh) / 2,
        (kRecoverablePacketLossAtLowBw + kRecoverablePacketLossAtHighBw) / 2 -
            kEpsilon},                                                  // B2
       {kBandwidthHigh + 1, kRecoverablePacketLossAtHighBw - kEpsilon}  // B3
   };

   std::vector<NetworkState> on{
       {kBandwidthLow, kRecoverablePacketLossAtLowBw + 0.1f},  // O1
       {kBandwidthLow, kRecoverablePacketLossAtLowBw},         // O2
       {(kBandwidthLow + kBandwidthHigh) / 2,
        (kRecoverablePacketLossAtLowBw + kRecoverablePacketLossAtHighBw) /
            2},                                               // O3
       {kBandwidthHigh, kRecoverablePacketLossAtHighBw},      // O4
       {kBandwidthHigh + 1, kRecoverablePacketLossAtHighBw},  // O5
   };

   std::vector<NetworkState> above{
       {(kBandwidthLow + kBandwidthHigh) / 2,
        (kRecoverablePacketLossAtLowBw + kRecoverablePacketLossAtHighBw) / 2 +
            kEpsilon},                                                   // A1
       {kBandwidthHigh + 1, kRecoverablePacketLossAtHighBw + kEpsilon},  // A2
   };

   // Test that FEC is turned off whenever we're below the curve, independent
   // of the starting FEC state.
   for (NetworkState net_state : below) {
     for (bool initial_fec_enabled : {false, true}) {
       FecControllerRplrBased controller(
           FecControllerRplrBased::Config(initial_fec_enabled, curve, curve));
       UpdateNetworkMetrics(&controller, net_state.bandwidth,
                            net_state.recoverable_packet_loss);
       CheckDecision(&controller, false, net_state.recoverable_packet_loss);
     }
   }

   // Test that FEC is turned on whenever we're on the curve or above it,
   // independent of the starting FEC state.
   for (const std::vector<NetworkState>& states_list : {on, above}) {
     for (NetworkState net_state : states_list) {
       for (bool initial_fec_enabled : {false, true}) {
         FecControllerRplrBased controller(
             FecControllerRplrBased::Config(initial_fec_enabled, curve, curve));
         UpdateNetworkMetrics(&controller, net_state.bandwidth,
                              net_state.recoverable_packet_loss);
         CheckDecision(&controller, true, net_state.recoverable_packet_loss);
       }
     }
   }
 }

 TEST(FecControllerRplrBasedTest, FecAlwaysOff) {
   ThresholdCurve always_off_curve(0, 1.0f + kEpsilon, 0, 1.0f + kEpsilon);
   for (bool initial_fec_enabled : {false, true}) {
     for (int bandwidth : {0, 10000}) {
       for (float recoverable_packet_loss : {0.0f, 0.5f, 1.0f}) {
         FecControllerRplrBased controller(FecControllerRplrBased::Config(
             initial_fec_enabled, always_off_curve, always_off_curve));
         UpdateNetworkMetrics(&controller, bandwidth, recoverable_packet_loss);
         CheckDecision(&controller, false, recoverable_packet_loss);
       }
     }
   }
 }

 TEST(FecControllerRplrBasedTest, FecAlwaysOn) {
   ThresholdCurve always_on_curve(0, 0.0f, 0, 0.0f);
   for (bool initial_fec_enabled : {false, true}) {
     for (int bandwidth : {0, 10000}) {
       for (float recoverable_packet_loss : {0.0f, 0.5f, 1.0f}) {
         FecControllerRplrBased controller(FecControllerRplrBased::Config(
             initial_fec_enabled, always_on_curve, always_on_curve));
         UpdateNetworkMetrics(&controller, bandwidth, recoverable_packet_loss);
         CheckDecision(&controller, true, recoverable_packet_loss);
       }
     }
   }
 }

 #if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
 TEST(FecControllerRplrBasedDeathTest, InvalidConfig) {
   EXPECT_DEATH(
       FecControllerRplrBased controller(FecControllerRplrBased::Config(
           true,
           ThresholdCurve(
               kDisablingBandwidthLow - 1, kEnablingRecoverablePacketLossAtLowBw,
               kEnablingBandwidthHigh, kEnablingRecoverablePacketLossAtHighBw),
           ThresholdCurve(kDisablingBandwidthLow,
                          kDisablingRecoverablePacketLossAtLowBw,
                          kDisablingBandwidthHigh,
                          kDisablingRecoverablePacketLossAtHighBw))),
       "Check failed");
 }
 #endif
 }  // namespace webrtc
	/*
	* Copyright (c) 2017 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 <random>
	#include <utility>

	#include "modules/audio_coding/audio_network_adaptor/fec_controller_rplr_based.h"
	#include "test/gtest.h"

	namespace webrtc {

	namespace {

	// The test uses the following settings:
	//
	// recoverable ^
	// packet-loss \| \| \|
	// \| A\| C\| FEC
	// \| \ \ ON
	// \| FEC \ D\_______
	// \| OFF B\_________
	// \|-----------------> bandwidth
	//
	// A : (kDisablingBandwidthLow, kDisablingRecoverablePacketLossAtLowBw)
	// B : (kDisablingBandwidthHigh, kDisablingRecoverablePacketLossAtHighBw)
	// C : (kEnablingBandwidthLow, kEnablingRecoverablePacketLossAtLowBw)
	// D : (kEnablingBandwidthHigh, kEnablingRecoverablePacketLossAtHighBw)

	constexpr int kDisablingBandwidthLow = 15000;
	constexpr float kDisablingRecoverablePacketLossAtLowBw = 0.08f;
	constexpr int kDisablingBandwidthHigh = 64000;
	constexpr float kDisablingRecoverablePacketLossAtHighBw = 0.01f;
	constexpr int kEnablingBandwidthLow = 17000;
	constexpr float kEnablingRecoverablePacketLossAtLowBw = 0.1f;
	constexpr int kEnablingBandwidthHigh = 64000;
	constexpr float kEnablingRecoverablePacketLossAtHighBw = 0.05f;

	constexpr float kEpsilon = 1e-5f;

	absl::optional<float> GetRandomProbabilityOrUnknown() {
	std::random_device rd;
	std::mt19937 generator(rd());
	std::uniform_real_distribution<> distribution(0, 1);

	return (distribution(generator) < 0.2)
	? absl::nullopt
	: absl::optional<float>(distribution(generator));
	}

	std::unique_ptr<FecControllerRplrBased> CreateFecControllerRplrBased(
	bool initial_fec_enabled) {
	return std::unique_ptr<FecControllerRplrBased>(
	new FecControllerRplrBased(FecControllerRplrBased::Config(
	initial_fec_enabled,
	ThresholdCurve(
	kEnablingBandwidthLow, kEnablingRecoverablePacketLossAtLowBw,
	kEnablingBandwidthHigh, kEnablingRecoverablePacketLossAtHighBw),
	ThresholdCurve(kDisablingBandwidthLow,
	kDisablingRecoverablePacketLossAtLowBw,
	kDisablingBandwidthHigh,
	kDisablingRecoverablePacketLossAtHighBw))));
	}

	void UpdateNetworkMetrics(
	FecControllerRplrBased* controller,
	const absl::optional<int>& uplink_bandwidth_bps,
	const absl::optional<float>& uplink_packet_loss,
	const absl::optional<float>& uplink_recoveralbe_packet_loss) {
	// UpdateNetworkMetrics can accept multiple network metric updates at once.
	// However, currently, the most used case is to update one metric at a time.
	// To reflect this fact, we separate the calls.
	if (uplink_bandwidth_bps) {
	Controller::NetworkMetrics network_metrics;
	network_metrics.uplink_bandwidth_bps = uplink_bandwidth_bps;
	controller->UpdateNetworkMetrics(network_metrics);
	}
	if (uplink_packet_loss) {
	Controller::NetworkMetrics network_metrics;
	network_metrics.uplink_packet_loss_fraction = uplink_packet_loss;
	controller->UpdateNetworkMetrics(network_metrics);
	}
	if (uplink_recoveralbe_packet_loss) {
	Controller::NetworkMetrics network_metrics;
	network_metrics.uplink_recoverable_packet_loss_fraction =
	uplink_recoveralbe_packet_loss;
	controller->UpdateNetworkMetrics(network_metrics);
	}
	}

	void UpdateNetworkMetrics(
	FecControllerRplrBased* controller,
	const absl::optional<int>& uplink_bandwidth_bps,
	const absl::optional<float>& uplink_recoveralbe_packet_loss) {
	// FecControllerRplrBased doesn't currently use the PLR (general packet-loss
	// rate) at all. (This might be changed in the future.) The unit-tests will
	// use a random value (including unknown), to show this does not interfere.
	UpdateNetworkMetrics(controller, uplink_bandwidth_bps,
	GetRandomProbabilityOrUnknown(),
	uplink_recoveralbe_packet_loss);
	}

	// Checks that the FEC decision and \|uplink_packet_loss_fraction\| given by
	// \|states->controller->MakeDecision\| matches \|expected_enable_fec\| and
	// \|expected_uplink_packet_loss_fraction\|, respectively.
	void CheckDecision(FecControllerRplrBased* controller,
	bool expected_enable_fec,
	float expected_uplink_packet_loss_fraction) {
	AudioEncoderRuntimeConfig config;
	controller->MakeDecision(&config);

	// Less compact than comparing optionals, but yields more readable errors.
	EXPECT_TRUE(config.enable_fec);
	if (config.enable_fec) {
	EXPECT_EQ(expected_enable_fec, *config.enable_fec);
	}
	EXPECT_TRUE(config.uplink_packet_loss_fraction);
	if (config.uplink_packet_loss_fraction) {
	EXPECT_EQ(expected_uplink_packet_loss_fraction,
	*config.uplink_packet_loss_fraction);
	}
	}

	} // namespace

	TEST(FecControllerRplrBasedTest, OutputInitValueBeforeAnyInputsAreReceived) {
	for (bool initial_fec_enabled : {false, true}) {
	auto controller = CreateFecControllerRplrBased(initial_fec_enabled);
	CheckDecision(controller.get(), initial_fec_enabled, 0);
	}
	}

	TEST(FecControllerRplrBasedTest, OutputInitValueWhenUplinkBandwidthUnknown) {
	// Regardless of the initial FEC state and the recoverable-packet-loss
	// rate, the initial FEC state is maintained as long as the BWE is unknown.
	for (bool initial_fec_enabled : {false, true}) {
	for (float recoverable_packet_loss :
	{kDisablingRecoverablePacketLossAtHighBw - kEpsilon,
	kDisablingRecoverablePacketLossAtHighBw,
	kDisablingRecoverablePacketLossAtHighBw + kEpsilon,
	kEnablingRecoverablePacketLossAtHighBw - kEpsilon,
	kEnablingRecoverablePacketLossAtHighBw,
	kEnablingRecoverablePacketLossAtHighBw + kEpsilon}) {
	auto controller = CreateFecControllerRplrBased(initial_fec_enabled);
	UpdateNetworkMetrics(controller.get(), absl::nullopt,
	recoverable_packet_loss);
	CheckDecision(controller.get(), initial_fec_enabled,
	recoverable_packet_loss);
	}
	}
	}

	TEST(FecControllerRplrBasedTest,
	OutputInitValueWhenUplinkRecoverablePacketLossFractionUnknown) {
	// Regardless of the initial FEC state and the BWE, the initial FEC state
	// is maintained as long as the recoverable-packet-loss rate is unknown.
	for (bool initial_fec_enabled : {false, true}) {
	for (int bandwidth : {kDisablingBandwidthLow - 1, kDisablingBandwidthLow,
	kDisablingBandwidthLow + 1, kEnablingBandwidthLow - 1,
	kEnablingBandwidthLow, kEnablingBandwidthLow + 1}) {
	auto controller = CreateFecControllerRplrBased(initial_fec_enabled);
	UpdateNetworkMetrics(controller.get(), bandwidth, absl::nullopt);
	CheckDecision(controller.get(), initial_fec_enabled, 0.0);
	}
	}
	}

	TEST(FecControllerRplrBasedTest, EnableFecForHighBandwidth) {
	auto controller = CreateFecControllerRplrBased(false);
	UpdateNetworkMetrics(controller.get(), kEnablingBandwidthHigh,
	kEnablingRecoverablePacketLossAtHighBw);
	CheckDecision(controller.get(), true, kEnablingRecoverablePacketLossAtHighBw);
	}

	TEST(FecControllerRplrBasedTest, UpdateMultipleNetworkMetricsAtOnce) {
	// This test is similar to EnableFecForHighBandwidth. But instead of
	// using ::UpdateNetworkMetrics(...), which calls
	// FecControllerRplrBasedTest::UpdateNetworkMetrics(...) multiple times, we
	// we call it only once. This is to verify that
	// FecControllerRplrBasedTest::UpdateNetworkMetrics(...) can handle multiple
	// network updates at once. This is, however, not a common use case in current
	// audio_network_adaptor_impl.cc.
	auto controller = CreateFecControllerRplrBased(false);
	Controller::NetworkMetrics network_metrics;
	network_metrics.uplink_bandwidth_bps = kEnablingBandwidthHigh;
	network_metrics.uplink_packet_loss_fraction = GetRandomProbabilityOrUnknown();
	network_metrics.uplink_recoverable_packet_loss_fraction =
	kEnablingRecoverablePacketLossAtHighBw;
	controller->UpdateNetworkMetrics(network_metrics);
	CheckDecision(controller.get(), true, kEnablingRecoverablePacketLossAtHighBw);
	}

	TEST(FecControllerRplrBasedTest, MaintainFecOffForHighBandwidth) {
	auto controller = CreateFecControllerRplrBased(false);
	constexpr float kRecoverablePacketLoss =
	kEnablingRecoverablePacketLossAtHighBw * 0.99f;
	UpdateNetworkMetrics(controller.get(), kEnablingBandwidthHigh,
	kRecoverablePacketLoss);
	CheckDecision(controller.get(), false, kRecoverablePacketLoss);
	}

	TEST(FecControllerRplrBasedTest, EnableFecForMediumBandwidth) {
	auto controller = CreateFecControllerRplrBased(false);
	constexpr float kRecoverablePacketLoss =
	(kEnablingRecoverablePacketLossAtLowBw +
	kEnablingRecoverablePacketLossAtHighBw) /
	2.0;
	UpdateNetworkMetrics(controller.get(),
	(kEnablingBandwidthHigh + kEnablingBandwidthLow) / 2,
	kRecoverablePacketLoss);
	CheckDecision(controller.get(), true, kRecoverablePacketLoss);
	}

	TEST(FecControllerRplrBasedTest, MaintainFecOffForMediumBandwidth) {
	auto controller = CreateFecControllerRplrBased(false);
	constexpr float kRecoverablePacketLoss =
	kEnablingRecoverablePacketLossAtLowBw * 0.49f +
	kEnablingRecoverablePacketLossAtHighBw * 0.51f;
	UpdateNetworkMetrics(controller.get(),
	(kEnablingBandwidthHigh + kEnablingBandwidthLow) / 2,
	kRecoverablePacketLoss);
	CheckDecision(controller.get(), false, kRecoverablePacketLoss);
	}

	TEST(FecControllerRplrBasedTest, EnableFecForLowBandwidth) {
	auto controller = CreateFecControllerRplrBased(false);
	UpdateNetworkMetrics(controller.get(), kEnablingBandwidthLow,
	kEnablingRecoverablePacketLossAtLowBw);
	CheckDecision(controller.get(), true, kEnablingRecoverablePacketLossAtLowBw);
	}

	TEST(FecControllerRplrBasedTest, MaintainFecOffForLowBandwidth) {
	auto controller = CreateFecControllerRplrBased(false);
	constexpr float kRecoverablePacketLoss =
	kEnablingRecoverablePacketLossAtLowBw * 0.99f;
	UpdateNetworkMetrics(controller.get(), kEnablingBandwidthLow,
	kRecoverablePacketLoss);
	CheckDecision(controller.get(), false, kRecoverablePacketLoss);
	}

	TEST(FecControllerRplrBasedTest, MaintainFecOffForVeryLowBandwidth) {
	auto controller = CreateFecControllerRplrBased(false);
	// Below \|kEnablingBandwidthLow\|, no recoverable packet loss fraction can
	// cause FEC to turn on.
	UpdateNetworkMetrics(controller.get(), kEnablingBandwidthLow - 1, 1.0);
	CheckDecision(controller.get(), false, 1.0);
	}

	TEST(FecControllerRplrBasedTest, DisableFecForHighBandwidth) {
	auto controller = CreateFecControllerRplrBased(true);
	constexpr float kRecoverablePacketLoss =
	kDisablingRecoverablePacketLossAtHighBw - kEpsilon;
	UpdateNetworkMetrics(controller.get(), kDisablingBandwidthHigh,
	kRecoverablePacketLoss);
	CheckDecision(controller.get(), false, kRecoverablePacketLoss);
	}

	TEST(FecControllerRplrBasedTest, MaintainFecOnForHighBandwidth) {
	// Note: Disabling happens when the value is strictly below the threshold.
	auto controller = CreateFecControllerRplrBased(true);
	UpdateNetworkMetrics(controller.get(), kDisablingBandwidthHigh,
	kDisablingRecoverablePacketLossAtHighBw);
	CheckDecision(controller.get(), true,
	kDisablingRecoverablePacketLossAtHighBw);
	}

	TEST(FecControllerRplrBasedTest, DisableFecOnMediumBandwidth) {
	auto controller = CreateFecControllerRplrBased(true);
	constexpr float kRecoverablePacketLoss =
	((kDisablingRecoverablePacketLossAtLowBw +
	kDisablingRecoverablePacketLossAtHighBw) /
	2.0f) -
	kEpsilon;
	UpdateNetworkMetrics(controller.get(),
	(kDisablingBandwidthHigh + kDisablingBandwidthLow) / 2,
	kRecoverablePacketLoss);
	CheckDecision(controller.get(), false, kRecoverablePacketLoss);
	}

	TEST(FecControllerRplrBasedTest, MaintainFecOnForMediumBandwidth) {
	auto controller = CreateFecControllerRplrBased(true);
	constexpr float kRecoverablePacketLoss =
	kDisablingRecoverablePacketLossAtLowBw * 0.51f +
	kDisablingRecoverablePacketLossAtHighBw * 0.49f - kEpsilon;
	UpdateNetworkMetrics(controller.get(),
	(kEnablingBandwidthHigh + kDisablingBandwidthLow) / 2,
	kRecoverablePacketLoss);
	CheckDecision(controller.get(), true, kRecoverablePacketLoss);
	}

	TEST(FecControllerRplrBasedTest, DisableFecForLowBandwidth) {
	auto controller = CreateFecControllerRplrBased(true);
	constexpr float kRecoverablePacketLoss =
	kDisablingRecoverablePacketLossAtLowBw - kEpsilon;
	UpdateNetworkMetrics(controller.get(), kDisablingBandwidthLow,
	kRecoverablePacketLoss);
	CheckDecision(controller.get(), false, kRecoverablePacketLoss);
	}

	TEST(FecControllerRplrBasedTest, DisableFecForVeryLowBandwidth) {
	auto controller = CreateFecControllerRplrBased(true);
	// Below \|kEnablingBandwidthLow\|, any recoverable packet loss fraction can
	// cause FEC to turn off.
	UpdateNetworkMetrics(controller.get(), kDisablingBandwidthLow - 1, 1.0);
	CheckDecision(controller.get(), false, 1.0);
	}

	TEST(FecControllerRplrBasedTest, CheckBehaviorOnChangingNetworkMetrics) {
	// In this test, we let the network metrics to traverse from 1 to 5.
	//
	// recoverable ^
	// packet-loss \| 1 \| \|
	// \| \| 2\|
	// \| \ \ 3
	// \| \4 \_______
	// \| \_________
	// \|---------5-------> bandwidth

	auto controller = CreateFecControllerRplrBased(true);
	UpdateNetworkMetrics(controller.get(), kDisablingBandwidthLow - 1, 1.0);
	CheckDecision(controller.get(), false, 1.0);

	UpdateNetworkMetrics(controller.get(), kEnablingBandwidthLow,
	kEnablingRecoverablePacketLossAtLowBw * 0.99f);
	CheckDecision(controller.get(), false,
	kEnablingRecoverablePacketLossAtLowBw * 0.99f);

	UpdateNetworkMetrics(controller.get(), kEnablingBandwidthHigh,
	kEnablingRecoverablePacketLossAtHighBw);
	CheckDecision(controller.get(), true, kEnablingRecoverablePacketLossAtHighBw);

	UpdateNetworkMetrics(controller.get(), kDisablingBandwidthHigh,
	kDisablingRecoverablePacketLossAtHighBw);
	CheckDecision(controller.get(), true,
	kDisablingRecoverablePacketLossAtHighBw);

	UpdateNetworkMetrics(controller.get(), kDisablingBandwidthHigh + 1, 0.0);
	CheckDecision(controller.get(), false, 0.0);
	}

	TEST(FecControllerRplrBasedTest, CheckBehaviorOnSpecialCurves) {
	// We test a special configuration, where the points to define the FEC
	// enabling/disabling curves are placed like the following, otherwise the test
	// is the same as CheckBehaviorOnChangingNetworkMetrics.
	//
	// recoverable ^
	// packet-loss \| \| \|
	// \| \| C\|
	// \| \| \|
	// \| \| D\|_______
	// \| A\|___B______
	// \|-----------------> bandwidth

	constexpr int kEnablingBandwidthHigh = kEnablingBandwidthLow;
	constexpr float kDisablingRecoverablePacketLossAtLowBw =
	kDisablingRecoverablePacketLossAtHighBw;
	FecControllerRplrBased controller(FecControllerRplrBased::Config(
	true,
	ThresholdCurve(
	kEnablingBandwidthLow, kEnablingRecoverablePacketLossAtLowBw,
	kEnablingBandwidthHigh, kEnablingRecoverablePacketLossAtHighBw),
	ThresholdCurve(
	kDisablingBandwidthLow, kDisablingRecoverablePacketLossAtLowBw,
	kDisablingBandwidthHigh, kDisablingRecoverablePacketLossAtHighBw)));

	UpdateNetworkMetrics(&controller, kDisablingBandwidthLow - 1, 1.0);
	CheckDecision(&controller, false, 1.0);

	UpdateNetworkMetrics(&controller, kEnablingBandwidthLow,
	kEnablingRecoverablePacketLossAtHighBw * 0.99f);
	CheckDecision(&controller, false,
	kEnablingRecoverablePacketLossAtHighBw * 0.99f);

	UpdateNetworkMetrics(&controller, kEnablingBandwidthHigh,
	kEnablingRecoverablePacketLossAtHighBw);
	CheckDecision(&controller, true, kEnablingRecoverablePacketLossAtHighBw);

	UpdateNetworkMetrics(&controller, kDisablingBandwidthHigh,
	kDisablingRecoverablePacketLossAtHighBw);
	CheckDecision(&controller, true, kDisablingRecoverablePacketLossAtHighBw);

	UpdateNetworkMetrics(&controller, kDisablingBandwidthHigh + 1, 0.0);
	CheckDecision(&controller, false, 0.0);
	}

	TEST(FecControllerRplrBasedTest, SingleThresholdCurveForEnablingAndDisabling) {
	// Note: To avoid numerical errors, keep kRecoverablePacketLossAtLowBw and
	// kRecoverablePacketLossAthighBw as (negative) integer powers of 2.
	// This is mostly relevant for the O3 case.
	constexpr int kBandwidthLow = 10000;
	constexpr float kRecoverablePacketLossAtLowBw = 0.25f;
	constexpr int kBandwidthHigh = 20000;
	constexpr float kRecoverablePacketLossAtHighBw = 0.125f;
	auto curve = ThresholdCurve(kBandwidthLow, kRecoverablePacketLossAtLowBw,
	kBandwidthHigh, kRecoverablePacketLossAtHighBw);

	// B* stands for "below-curve", O* for "on-curve", and A* for "above-curve".
	//
	// //
	// recoverable ^ //
	// packet-loss \| \| //
	// \| B1 O1 //
	// \| \| //
	// \| O2 //
	// \| \ A1 //
	// \| \ //
	// \| O3 A2 //
	// \| B2 \ //
	// \| \ //
	// \| O4--O5---- //
	// \| //
	// \| B3 //
	// \|-----------------> bandwidth //

	struct NetworkState {
	int bandwidth;
	float recoverable_packet_loss;
	};

	std::vector<NetworkState> below{
	{kBandwidthLow - 1, kRecoverablePacketLossAtLowBw + 0.1f}, // B1
	{(kBandwidthLow + kBandwidthHigh) / 2,
	(kRecoverablePacketLossAtLowBw + kRecoverablePacketLossAtHighBw) / 2 -
	kEpsilon}, // B2
	{kBandwidthHigh + 1, kRecoverablePacketLossAtHighBw - kEpsilon} // B3
	};

	std::vector<NetworkState> on{
	{kBandwidthLow, kRecoverablePacketLossAtLowBw + 0.1f}, // O1
	{kBandwidthLow, kRecoverablePacketLossAtLowBw}, // O2
	{(kBandwidthLow + kBandwidthHigh) / 2,
	(kRecoverablePacketLossAtLowBw + kRecoverablePacketLossAtHighBw) /
	2}, // O3
	{kBandwidthHigh, kRecoverablePacketLossAtHighBw}, // O4
	{kBandwidthHigh + 1, kRecoverablePacketLossAtHighBw}, // O5
	};

	std::vector<NetworkState> above{
	{(kBandwidthLow + kBandwidthHigh) / 2,
	(kRecoverablePacketLossAtLowBw + kRecoverablePacketLossAtHighBw) / 2 +
	kEpsilon}, // A1
	{kBandwidthHigh + 1, kRecoverablePacketLossAtHighBw + kEpsilon}, // A2
	};

	// Test that FEC is turned off whenever we're below the curve, independent
	// of the starting FEC state.
	for (NetworkState net_state : below) {
	for (bool initial_fec_enabled : {false, true}) {
	FecControllerRplrBased controller(
	FecControllerRplrBased::Config(initial_fec_enabled, curve, curve));
	UpdateNetworkMetrics(&controller, net_state.bandwidth,
	net_state.recoverable_packet_loss);
	CheckDecision(&controller, false, net_state.recoverable_packet_loss);
	}
	}

	// Test that FEC is turned on whenever we're on the curve or above it,
	// independent of the starting FEC state.
	for (const std::vector<NetworkState>& states_list : {on, above}) {
	for (NetworkState net_state : states_list) {
	for (bool initial_fec_enabled : {false, true}) {
	FecControllerRplrBased controller(
	FecControllerRplrBased::Config(initial_fec_enabled, curve, curve));
	UpdateNetworkMetrics(&controller, net_state.bandwidth,
	net_state.recoverable_packet_loss);
	CheckDecision(&controller, true, net_state.recoverable_packet_loss);
	}
	}
	}
	}

	TEST(FecControllerRplrBasedTest, FecAlwaysOff) {
	ThresholdCurve always_off_curve(0, 1.0f + kEpsilon, 0, 1.0f + kEpsilon);
	for (bool initial_fec_enabled : {false, true}) {
	for (int bandwidth : {0, 10000}) {
	for (float recoverable_packet_loss : {0.0f, 0.5f, 1.0f}) {
	FecControllerRplrBased controller(FecControllerRplrBased::Config(
	initial_fec_enabled, always_off_curve, always_off_curve));
	UpdateNetworkMetrics(&controller, bandwidth, recoverable_packet_loss);
	CheckDecision(&controller, false, recoverable_packet_loss);
	}
	}
	}
	}

	TEST(FecControllerRplrBasedTest, FecAlwaysOn) {
	ThresholdCurve always_on_curve(0, 0.0f, 0, 0.0f);
	for (bool initial_fec_enabled : {false, true}) {
	for (int bandwidth : {0, 10000}) {
	for (float recoverable_packet_loss : {0.0f, 0.5f, 1.0f}) {
	FecControllerRplrBased controller(FecControllerRplrBased::Config(
	initial_fec_enabled, always_on_curve, always_on_curve));
	UpdateNetworkMetrics(&controller, bandwidth, recoverable_packet_loss);
	CheckDecision(&controller, true, recoverable_packet_loss);
	}
	}
	}
	}

	#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
	TEST(FecControllerRplrBasedDeathTest, InvalidConfig) {
	EXPECT_DEATH(
	FecControllerRplrBased controller(FecControllerRplrBased::Config(
	true,
	ThresholdCurve(
	kDisablingBandwidthLow - 1, kEnablingRecoverablePacketLossAtLowBw,
	kEnablingBandwidthHigh, kEnablingRecoverablePacketLossAtHighBw),
	ThresholdCurve(kDisablingBandwidthLow,
	kDisablingRecoverablePacketLossAtLowBw,
	kDisablingBandwidthHigh,
	kDisablingRecoverablePacketLossAtHighBw))),
	"Check failed");
	}
	#endif
	} // namespace webrtc