Adding FecController to audio network adaptor.

webrtc/modules/audio_coding/audio_network_adaptor/fec_controller_unittest.cc

Index: webrtc/modules/audio_coding/audio_network_adaptor/fec_controller_unittest.cc
diff --git a/webrtc/modules/audio_coding/audio_network_adaptor/fec_controller_unittest.cc b/webrtc/modules/audio_coding/audio_network_adaptor/fec_controller_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c70284028dc52b93e42c3d187f97875a8c1df74e
--- /dev/null
+++ b/webrtc/modules/audio_coding/audio_network_adaptor/fec_controller_unittest.cc
@@ -0,0 +1,314 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <utility>
+
+#include "webrtc/modules/audio_coding/audio_network_adaptor/fec_controller.h"
+#include "webrtc/modules/audio_coding/audio_network_adaptor/mock/mock_smoothing_filter.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace webrtc {
+
+using ::testing::NiceMock;
+using ::testing::Return;
+using ::testing::_;
+
+namespace {
+
+// The test uses the following settings:
+//
+// packet-loss ^   |  |
+//             |  A| C|   FEC
+//             |    \  \   ON
+//             | FEC \ D\_______
+//             | OFF B\_________
+//             |-----------------> bandwidth
+//
+// A : (kDisablingBandwidthLow, kDisablingPacketLossAtLowBw)
+// B : (kDisablingBandwidthHigh, kDisablingPacketLossAtHighBw)
+// C : (kEnablingBandwidthLow, kEnablingPacketLossAtLowBw)
+// D : (kEnablingBandwidthHigh, kEnablingPacketLossAtHighBw)
+
+constexpr int kDisablingBandwidthLow = 15000;
+constexpr float kDisablingPacketLossAtLowBw = 0.08f;
+constexpr int kDisablingBandwidthHigh = 64000;
+constexpr float kDisablingPacketLossAtHighBw = 0.01f;
+constexpr int kEnablingBandwidthLow = 17000;
+constexpr float kEnablingPacketLossAtLowBw = 0.1f;
+constexpr int kEnablingBandwidthHigh = 64000;
+constexpr float kEnablingPacketLossAtHighBw = 0.05f;
+
+struct FecControllerStates {
+  std::unique_ptr<FecController> controller;
+  MockSmoothingFilter* packet_loss_smoothed;
+};
+
+FecControllerStates CreateFecController(bool initial_fec_enabled) {
+  FecControllerStates states;
+  std::unique_ptr<MockSmoothingFilter> mock_smoothing_filter(
+      new NiceMock<MockSmoothingFilter>());
+  states.packet_loss_smoothed = mock_smoothing_filter.get();
+  EXPECT_CALL(*states.packet_loss_smoothed, Die());
+  using Threshold = FecController::Config::Threshold;
+  states.controller.reset(new FecController(
+      FecController::Config(
+          initial_fec_enabled,
+          Threshold(kEnablingBandwidthLow, kEnablingPacketLossAtLowBw,
+                    kEnablingBandwidthHigh, kEnablingPacketLossAtHighBw),
+          Threshold(kDisablingBandwidthLow, kDisablingPacketLossAtLowBw,
+                    kDisablingBandwidthHigh, kDisablingPacketLossAtHighBw),
+          0, nullptr),
+      std::move(mock_smoothing_filter)));
+  return states;
+}
+
+// Checks that the FEC decision given by |states->controller->MakeDecision|
+// matches |expected_enable_fec|. It also checks that
+// |uplink_packet_loss_fraction| returned by |states->controller->MakeDecision|
+// matches |uplink_packet_loss|.
+void CheckDecision(FecControllerStates* states,
+                   const rtc::Optional<int>& uplink_bandwidth_bps,
+                   const rtc::Optional<float>& uplink_packet_loss,
+                   bool expected_enable_fec) {
+  Controller::NetworkMetrics metrics;
+  metrics.uplink_bandwidth_bps = uplink_bandwidth_bps;
+  metrics.uplink_packet_loss_fraction = uplink_packet_loss;
+
+  if (uplink_packet_loss) {
+    // Check that smoothing filter is updated.
+    EXPECT_CALL(*states->packet_loss_smoothed, AddSample(*uplink_packet_loss));
+  }
+
+  EXPECT_CALL(*states->packet_loss_smoothed, GetAverage())
+      .WillRepeatedly(Return(uplink_packet_loss));
+
+  AudioNetworkAdaptor::EncoderRuntimeConfig config;
+  states->controller->MakeDecision(metrics, &config);
+  EXPECT_EQ(rtc::Optional<bool>(expected_enable_fec), config.enable_fec);
+
+  // Check that |config.uplink_packet_loss_fraction| is properly filled.
+  EXPECT_EQ(expected_enable_fec && uplink_packet_loss
+                ? uplink_packet_loss
+                : rtc::Optional<float>(0.0),
+            config.uplink_packet_loss_fraction);
+}
+
+}  // namespace
+
+TEST(FecControllerTest, OutputInitValueWhenUplinkBandwidthUnknown) {
+  constexpr bool kInitialFecEnabled = true;
+  auto states = CreateFecController(kInitialFecEnabled);
+  // Let uplink packet loss fraction be so low that would cause FEC to turn off
+  // if uplink bandwidth was known.
+  CheckDecision(&states, rtc::Optional<int>(),
+                rtc::Optional<float>(kDisablingPacketLossAtHighBw),
+                kInitialFecEnabled);
+}
+
+TEST(FecControllerTest, OutputInitValueWhenUplinkPacketLossFractionUnknown) {
+  constexpr bool kInitialFecEnabled = true;
+  auto states = CreateFecController(kInitialFecEnabled);
+  // Let uplink bandwidth be so low that would cause FEC to turn off if uplink
+  // bandwidth packet loss fraction was known.
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthLow - 1),
+                rtc::Optional<float>(), kInitialFecEnabled);
+}
+
+TEST(FecControllerTest, EnableFecForHighBandwidth) {
+  auto states = CreateFecController(false);
+  CheckDecision(&states, rtc::Optional<int>(kEnablingBandwidthHigh),
+                rtc::Optional<float>(kEnablingPacketLossAtHighBw), true);
+}
+
+TEST(FecControllerTest, MaintainFecOffForHighBandwidth) {
+  auto states = CreateFecController(false);
+  CheckDecision(&states, rtc::Optional<int>(kEnablingBandwidthHigh),
+                rtc::Optional<float>(kEnablingPacketLossAtHighBw * 0.99f),
+                false);
+}
+
+TEST(FecControllerTest, EnableFecForMediumBandwidth) {
+  auto states = CreateFecController(false);
+  CheckDecision(
+      &states,
+      rtc::Optional<int>((kEnablingBandwidthHigh + kEnablingBandwidthLow) / 2),
+      rtc::Optional<float>(
+          (kEnablingPacketLossAtLowBw + kEnablingPacketLossAtHighBw) / 2.0),
+      true);
+}
+
+TEST(FecControllerTest, MaintainFecOffForMediumBandwidth) {
+  auto states = CreateFecController(false);
+  CheckDecision(
+      &states,
+      rtc::Optional<int>((kEnablingBandwidthHigh + kEnablingBandwidthLow) / 2),
+      rtc::Optional<float>(kEnablingPacketLossAtLowBw * 0.49f +
+                           kEnablingPacketLossAtHighBw * 0.51f),
+      false);
+}
+
+TEST(FecControllerTest, EnableFecForLowBandwidth) {
+  auto states = CreateFecController(false);
+  CheckDecision(&states, rtc::Optional<int>(kEnablingBandwidthLow),
+                rtc::Optional<float>(kEnablingPacketLossAtLowBw), true);
+}
+
+TEST(FecControllerTest, MaintainFecOffForLowBandwidth) {
+  auto states = CreateFecController(false);
+  CheckDecision(&states, rtc::Optional<int>(kEnablingBandwidthLow),
+                rtc::Optional<float>(kEnablingPacketLossAtLowBw * 0.99f),
+                false);
+}
+
+TEST(FecControllerTest, MaintainFecOffForVeryLowBandwidth) {
+  auto states = CreateFecController(false);
+  // Below |kEnablingBandwidthLow|, no packet loss fraction can cause FEC to
+  // turn on.
+  CheckDecision(&states, rtc::Optional<int>(kEnablingBandwidthLow - 1),
+                rtc::Optional<float>(1.0), false);
+}
+
+TEST(FecControllerTest, DisableFecForHighBandwidth) {
+  auto states = CreateFecController(true);
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthHigh),
+                rtc::Optional<float>(kDisablingPacketLossAtHighBw), false);
+}
+
+TEST(FecControllerTest, MaintainFecOnForHighBandwidth) {
+  auto states = CreateFecController(true);
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthHigh),
+                rtc::Optional<float>(kDisablingPacketLossAtHighBw * 1.01f),
+                true);
+}
+
+TEST(FecControllerTest, DisableFecOnMediumBandwidth) {
+  auto states = CreateFecController(true);
+  CheckDecision(
+      &states, rtc::Optional<int>(
+                   (kDisablingBandwidthHigh + kDisablingBandwidthLow) / 2),
+      rtc::Optional<float>(
+          (kDisablingPacketLossAtLowBw + kDisablingPacketLossAtHighBw) / 2.0f),
+      false);
+}
+
+TEST(FecControllerTest, MaintainFecOnForMediumBandwidth) {
+  auto states = CreateFecController(true);
+  CheckDecision(
+      &states,
+      rtc::Optional<int>((kEnablingBandwidthHigh + kDisablingBandwidthLow) / 2),
+      rtc::Optional<float>(kDisablingPacketLossAtLowBw * 0.51f +
+                           kDisablingPacketLossAtHighBw * 0.49f),
+      true);
+}
+
+TEST(FecControllerTest, DisableFecForLowBandwidth) {
+  auto states = CreateFecController(true);
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthLow),
+                rtc::Optional<float>(kDisablingPacketLossAtLowBw), false);
+}
+
+TEST(FecControllerTest, DisableFecForVeryLowBandwidth) {
+  auto states = CreateFecController(true);
+  // Below |kEnablingBandwidthLow|, any packet loss fraction can cause FEC to
+  // turn off.
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthLow - 1),
+                rtc::Optional<float>(1.0), false);
+}
+
+TEST(FecControllerTest, CheckBehaviorOnChangingNetworkMetrics) {
+  // In this test, we let the network metrics to traverse from 1 to 5.
+  // packet-loss ^ 1 |  |
+  //             |   | 2|
+  //             |    \  \ 3
+  //             |     \4 \_______
+  //             |      \_________
+  //             |---------5-------> bandwidth
+
+  auto states = CreateFecController(true);
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthLow - 1),
+                rtc::Optional<float>(1.0), false);
+  CheckDecision(&states, rtc::Optional<int>(kEnablingBandwidthLow),
+                rtc::Optional<float>(kEnablingPacketLossAtLowBw * 0.99f),
+                false);
+  CheckDecision(&states, rtc::Optional<int>(kEnablingBandwidthHigh),
+                rtc::Optional<float>(kEnablingPacketLossAtHighBw), true);
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthHigh),
+                rtc::Optional<float>(kDisablingPacketLossAtHighBw * 1.01f),
+                true);
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthHigh + 1),
+                rtc::Optional<float>(0.0), false);
+}
+
+TEST(FecControllerTest, 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.
+  //
+  // packet-loss ^   |  |
+  //             |   | C|
+  //             |   |  |
+  //             |   | D|_______
+  //             |  A|___B______
+  //             |-----------------> bandwidth
+
+  constexpr int kEnablingBandwidthHigh = kEnablingBandwidthLow;
+  constexpr float kDisablingPacketLossAtLowBw = kDisablingPacketLossAtHighBw;
+  FecControllerStates states;
+  std::unique_ptr<MockSmoothingFilter> mock_smoothing_filter(
+      new NiceMock<MockSmoothingFilter>());
+  states.packet_loss_smoothed = mock_smoothing_filter.get();
+  EXPECT_CALL(*states.packet_loss_smoothed, Die());
+  using Threshold = FecController::Config::Threshold;
+  states.controller.reset(new FecController(
+      FecController::Config(
+          true, Threshold(kEnablingBandwidthLow, kEnablingPacketLossAtLowBw,
+                          kEnablingBandwidthHigh, kEnablingPacketLossAtHighBw),
+          Threshold(kDisablingBandwidthLow, kDisablingPacketLossAtLowBw,
+                    kDisablingBandwidthHigh, kDisablingPacketLossAtHighBw),
+          0, nullptr),
+      std::move(mock_smoothing_filter)));
+
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthLow - 1),
+                rtc::Optional<float>(1.0), false);
+  CheckDecision(&states, rtc::Optional<int>(kEnablingBandwidthLow),
+                rtc::Optional<float>(kEnablingPacketLossAtHighBw * 0.99f),
+                false);
+  CheckDecision(&states, rtc::Optional<int>(kEnablingBandwidthHigh),
+                rtc::Optional<float>(kEnablingPacketLossAtHighBw), true);
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthHigh),
+                rtc::Optional<float>(kDisablingPacketLossAtHighBw * 1.01f),
+                true);
+  CheckDecision(&states, rtc::Optional<int>(kDisablingBandwidthHigh + 1),
+                rtc::Optional<float>(0.0), false);
+}
+
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+TEST(FecControllerDeathTest, InvalidConfig) {
+  FecControllerStates states;
+  std::unique_ptr<MockSmoothingFilter> mock_smoothing_filter(
+      new NiceMock<MockSmoothingFilter>());
+  states.packet_loss_smoothed = mock_smoothing_filter.get();
+  EXPECT_CALL(*states.packet_loss_smoothed, Die());
+  using Threshold = FecController::Config::Threshold;
+  EXPECT_DEBUG_DEATH(
+      states.controller.reset(new FecController(
+          FecController::Config(
+              true,
+              Threshold(kDisablingBandwidthLow - 1, kEnablingPacketLossAtLowBw,
+                        kEnablingBandwidthHigh, kEnablingPacketLossAtHighBw),
+              Threshold(kDisablingBandwidthLow, kDisablingPacketLossAtLowBw,
+                        kDisablingBandwidthHigh, kDisablingPacketLossAtHighBw),
+              0, nullptr),
+          std::move(mock_smoothing_filter))),
+      "Check failed");
+}
+#endif
+
+}  // namespace webrtc