Instantly pass network changes to controllers in audio network adaptor.

webrtc/modules/audio_coding/audio_network_adaptor/fec_controller.cc

 /*
  *  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.
  */
 
@@ skipping 22 matching lines @@
                               const Clock* clock)
     : initial_fec_enabled(initial_fec_enabled),
       fec_enabling_threshold(fec_enabling_threshold),
       fec_disabling_threshold(fec_disabling_threshold),
       time_constant_ms(time_constant_ms),
       clock(clock) {}
 
 FecController::FecController(const Config& config)
     : config_(config),
       fec_enabled_(config.initial_fec_enabled),
-      packet_loss_smoothed_(
+      packet_loss_smoother_(
           new SmoothingFilterImpl(config_.time_constant_ms, config_.clock)),
       fec_enabling_threshold_info_(config_.fec_enabling_threshold),
       fec_disabling_threshold_info_(config_.fec_disabling_threshold) {
   RTC_DCHECK_LE(fec_enabling_threshold_info_.slope, 0);
   RTC_DCHECK_LE(fec_enabling_threshold_info_.slope, 0);
   RTC_DCHECK_LE(
       GetPacketLossThreshold(config_.fec_enabling_threshold.low_bandwidth_bps,
                              config_.fec_disabling_threshold,
                              fec_disabling_threshold_info_),
       config_.fec_enabling_threshold.low_bandwidth_packet_loss);
   RTC_DCHECK_LE(
       GetPacketLossThreshold(config_.fec_enabling_threshold.high_bandwidth_bps,
                              config_.fec_disabling_threshold,
                              fec_disabling_threshold_info_),
       config_.fec_enabling_threshold.high_bandwidth_packet_loss);
 }
 
 FecController::FecController(const Config& config,
                              std::unique_ptr<SmoothingFilter> smoothing_filter)
     : FecController(config) {
-  packet_loss_smoothed_ = std::move(smoothing_filter);

[michaelt, 2017/01/23 15:15:52]

I would prefer to make packet_loss_smoothed_ const

+  packet_loss_smoother_ = std::move(smoothing_filter);
 }
 
 FecController::~FecController() = default;
 
+void FecController::UpdateNetworkMetrics(
+    const NetworkMetrics& network_metrics) {
+  if (network_metrics.uplink_bandwidth_bps)
+    uplink_bandwidth_bps_ = network_metrics.uplink_bandwidth_bps;
+  if (network_metrics.uplink_packet_loss_fraction) {
+    packet_loss_smoother_->AddSample(
+        *network_metrics.uplink_packet_loss_fraction);
+  }
+}
+
 void FecController::MakeDecision(
-    const NetworkMetrics& metrics,
     AudioNetworkAdaptor::EncoderRuntimeConfig* config) {
   RTC_DCHECK(!config->enable_fec);
   RTC_DCHECK(!config->uplink_packet_loss_fraction);
 
-  if (metrics.uplink_packet_loss_fraction)
-    packet_loss_smoothed_->AddSample(*metrics.uplink_packet_loss_fraction);
+  const auto& packet_loss = packet_loss_smoother_->GetAverage();
 
-  const auto& packet_loss = packet_loss_smoothed_->GetAverage();
-
-  fec_enabled_ = fec_enabled_ ? !FecDisablingDecision(metrics, packet_loss)
-                              : FecEnablingDecision(metrics, packet_loss);
+  fec_enabled_ = fec_enabled_ ? !FecDisablingDecision(packet_loss)
+                              : FecEnablingDecision(packet_loss);
 
   config->enable_fec = rtc::Optional<bool>(fec_enabled_);
 
-  auto packet_loss_fraction = packet_loss_smoothed_->GetAverage();
-  config->uplink_packet_loss_fraction = rtc::Optional<float>(
-      packet_loss_fraction ? *packet_loss_fraction : 0.0);
+  config->uplink_packet_loss_fraction =
+      rtc::Optional<float>(packet_loss ? *packet_loss : 0.0);
 }
 
 FecController::ThresholdInfo::ThresholdInfo(
     const Config::Threshold& threshold) {
   int bandwidth_diff_bps =
       threshold.high_bandwidth_bps - threshold.low_bandwidth_bps;
   float packet_loss_diff = threshold.high_bandwidth_packet_loss -
                            threshold.low_bandwidth_packet_loss;
   slope = bandwidth_diff_bps == 0 ? 0.0 : packet_loss_diff / bandwidth_diff_bps;
   offset =
       threshold.low_bandwidth_packet_loss - slope * threshold.low_bandwidth_bps;
 }
 
 float FecController::GetPacketLossThreshold(
     int bandwidth_bps,
     const Config::Threshold& threshold,
     const ThresholdInfo& threshold_info) const {
   if (bandwidth_bps < threshold.low_bandwidth_bps)
     return std::numeric_limits<float>::max();
   if (bandwidth_bps >= threshold.high_bandwidth_bps)
     return threshold.high_bandwidth_packet_loss;
   return threshold_info.offset + threshold_info.slope * bandwidth_bps;
 }
 
 bool FecController::FecEnablingDecision(
-    const NetworkMetrics& metrics,
     const rtc::Optional<float>& packet_loss) const {
-  if (!metrics.uplink_bandwidth_bps)
+  if (!uplink_bandwidth_bps_)
     return false;
   if (!packet_loss)
     return false;
-  return *packet_loss >= GetPacketLossThreshold(*metrics.uplink_bandwidth_bps,
+  return *packet_loss >= GetPacketLossThreshold(*uplink_bandwidth_bps_,
                                                 config_.fec_enabling_threshold,
                                                 fec_enabling_threshold_info_);
 }
 
 bool FecController::FecDisablingDecision(
-    const NetworkMetrics& metrics,
     const rtc::Optional<float>& packet_loss) const {
-  if (!metrics.uplink_bandwidth_bps)
+  if (!uplink_bandwidth_bps_)
     return false;
   if (!packet_loss)
     return false;
-  return *packet_loss <= GetPacketLossThreshold(*metrics.uplink_bandwidth_bps,
+  return *packet_loss <= GetPacketLossThreshold(*uplink_bandwidth_bps_,
                                                 config_.fec_disabling_threshold,
                                                 fec_disabling_threshold_info_);
 }
 
 }  // namespace webrtc