Reland of added functionality for specifying the initial signal level to use for the gain estimation

webrtc/modules/audio_processing/level_controller/level_controller.cc

Index: webrtc/modules/audio_processing/level_controller/level_controller.cc
diff --git a/webrtc/modules/audio_processing/level_controller/level_controller.cc b/webrtc/modules/audio_processing/level_controller/level_controller.cc
index c0edeb91c50f5a472019f07eb45ce97910d9ea12..1ec20201d8640fcf2b7955af53fcff0fd9530001 100644
--- a/webrtc/modules/audio_processing/level_controller/level_controller.cc
+++ b/webrtc/modules/audio_processing/level_controller/level_controller.cc
@@ -240,8 +240,12 @@ void LevelController::Process(AudioBuffer* audio) {
   float saturating_gain = saturating_gain_estimator_.GetGain();
 
   // Compute the new gain to apply.
-  last_gain_ = gain_selector_.GetNewGain(long_term_peak_level, noise_energy,
-                                         saturating_gain, signal_type);
+  last_gain_ =
+      gain_selector_.GetNewGain(long_term_peak_level, noise_energy,
+                                saturating_gain, gain_jumpstart_, signal_type);
+
+  // Unflag the jumpstart of the gain as it should only happen once.
+  gain_jumpstart_ = false;
 
   // Apply the gain to the signal.
   int num_saturations = gain_applier_.Process(last_gain_, audio);
@@ -262,17 +266,35 @@ void LevelController::Process(AudioBuffer* audio) {
                         audio->channels_f()[0], *sample_rate_hz_, 1);
 }
 
+void LevelController::ApplyConfig(
+    const AudioProcessing::Config::LevelController& config) {
+  if (config.initial_level) {
+    peak_level_estimator_.SetInitialPeakLevel(*config.initial_level);
+    gain_jumpstart_ = true;
+  }
+}
+
 std::string LevelController::ToString(
     const AudioProcessing::Config::LevelController& config) {
   std::stringstream ss;
   ss << "{"
-     << "enabled: " << (config.enabled ? "true" : "false") << "}";
+     << "enabled: " << (config.enabled ? "true" : "false") << ","
+     << "initial level: : ";
+  if (config.initial_level) {
+    ss << *config.initial_level;
+  } else {
+    ss << "Not specified";
+  }
+  ss << "}";
   return ss.str();
 }
 
 bool LevelController::Validate(
     const AudioProcessing::Config::LevelController& config) {
-  return true;
+  return !config.initial_level ||
+         (*config.initial_level < std::numeric_limits<float>::epsilon() &&

[the sun, 2016/09/16 08:00:40]

In the future, consider making a utility for this (if there isn't one in the std
lib) - e.g. InRange(min, x, max)

[peah-webrtc, 2016/09/16 11:36:05]

Acknowledged.

+          *config.initial_level >
+              -(100.f + std::numeric_limits<float>::epsilon()));
 }
 
 }  // namespace webrtc