Adding ChannelController to audio network adaptor.

webrtc/modules/audio_coding/audio_network_adaptor/channel_controller_unittest.cc

Index: webrtc/modules/audio_coding/audio_network_adaptor/channel_controller_unittest.cc
diff --git a/webrtc/modules/audio_coding/audio_network_adaptor/channel_controller_unittest.cc b/webrtc/modules/audio_coding/audio_network_adaptor/channel_controller_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2377ebf3d41ee465e5a3a2f13a5e8af1e86faeb4
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+++ b/webrtc/modules/audio_coding/audio_network_adaptor/channel_controller_unittest.cc
@@ -0,0 +1,113 @@
+/*
+ *  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 <memory>
+
+#include "webrtc/modules/audio_coding/audio_network_adaptor/channel_controller.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace webrtc {
+
+namespace {
+
+constexpr int kNumChannels = 2;
+constexpr int kChannel1To2BandwidthBps = 31000;
+constexpr int kChannel2To1BandwidthBps = 29000;
+constexpr int kMediumBandwidthBps =
+    (kChannel1To2BandwidthBps + kChannel2To1BandwidthBps) / 2;
+
+std::unique_ptr<ChannelController> CreateChannelController(int init_channels) {

[minyue-webrtc, 2016/09/14 06:52:39]

added this helper function to make test code more concise.

+  std::unique_ptr<ChannelController> controller(
+      new ChannelController(ChannelController::Config(
+          kNumChannels, init_channels, kChannel1To2BandwidthBps,
+          kChannel2To1BandwidthBps)));
+  return controller;
+}
+
+void CheckDecision(ChannelController* controller,

[minyue-webrtc, 2016/09/14 06:52:39]

renamed this function since ChannelControllers in
CheckChannelControllersDecision is redundant.

+                   const Controller::NetworkMetrics& metrics,
+                   size_t expected_num_channels) {
+  AudioNetworkAdaptor::EncoderRuntimeConfig config;
+  controller->MakeDecision(metrics, &config);
+  EXPECT_EQ(rtc::Optional<size_t>(expected_num_channels), config.num_channels);
+}
+
+}  // namespace
+
+TEST(ChannelControllerTest, OutputInitValueWhenUplinkBandwidthUnknown) {
+  constexpr int kInitChannels = 2;
+  auto controller = CreateChannelController(kInitChannels);
+  Controller::NetworkMetrics metrics;
+  CheckDecision(controller.get(), metrics, kInitChannels);
+}
+
+TEST(ChannelControllerTest, SwitchTo2ChannelsOnHighUplinkBandwidth) {
+  constexpr int kInitChannels = 1;
+  auto controller = CreateChannelController(kInitChannels);
+  Controller::NetworkMetrics metrics;
+
+  // Use high bandwidth to check output switch to 2.
+  metrics.uplink_bandwidth_bps = rtc::Optional<int>(kChannel1To2BandwidthBps);
+  CheckDecision(controller.get(), metrics, 2);
+}
+
+TEST(ChannelControllerTest, SwitchTo1ChannelOnLowUplinkBandwidth) {
+  constexpr int kInitChannels = 2;
+  auto controller = CreateChannelController(kInitChannels);
+  Controller::NetworkMetrics metrics;
+
+  // Use low bandwidth to check output switch to 1.
+  metrics.uplink_bandwidth_bps = rtc::Optional<int>(kChannel2To1BandwidthBps);
+  CheckDecision(controller.get(), metrics, 1);
+}
+
+TEST(ChannelControllerTest, Maintain1ChannelOnMediumUplinkBandwidth) {
+  constexpr int kInitChannels = 1;
+  auto controller = CreateChannelController(kInitChannels);
+  Controller::NetworkMetrics metrics;
+
+  // Use between-thresholds bandwidth to check output remains at 1.
+  metrics.uplink_bandwidth_bps = rtc::Optional<int>(kMediumBandwidthBps);
+  CheckDecision(controller.get(), metrics, 1);
+}
+
+TEST(ChannelControllerTest, Maintain2ChannelsOnMediumUplinkBandwidth) {
+  constexpr int kInitChannels = 2;
+  auto controller = CreateChannelController(kInitChannels);
+  Controller::NetworkMetrics metrics;
+
+  // Use between-thresholds bandwidth to check output remains at 2.
+  metrics.uplink_bandwidth_bps = rtc::Optional<int>(kMediumBandwidthBps);
+  CheckDecision(controller.get(), metrics, 2);
+}
+
+TEST(ChannelControllerTest, CheckBehaviorOnChangingUplinkBandwidth) {

[minyue-webrtc, 2016/09/14 06:52:39]

added a test to cover sequential changes

+  constexpr int kInitChannels = 1;
+  auto controller = CreateChannelController(kInitChannels);
+  Controller::NetworkMetrics metrics;
+
+  // Use between-thresholds bandwidth to check output remains at 1.
+  metrics.uplink_bandwidth_bps = rtc::Optional<int>(kMediumBandwidthBps);
+  CheckDecision(controller.get(), metrics, 1);
+
+  // Use high bandwidth to check output switch to 2.
+  metrics.uplink_bandwidth_bps = rtc::Optional<int>(kChannel1To2BandwidthBps);
+  CheckDecision(controller.get(), metrics, 2);
+
+  // Use between-thresholds bandwidth to check output remains at 2.
+  metrics.uplink_bandwidth_bps = rtc::Optional<int>(kMediumBandwidthBps);
+  CheckDecision(controller.get(), metrics, 2);
+
+  // Use low bandwidth to check output switch to 1.
+  metrics.uplink_bandwidth_bps = rtc::Optional<int>(kChannel2To1BandwidthBps);
+  CheckDecision(controller.get(), metrics, 1);
+}
+
+}  // namespace webrtc