Added functionality for specifying the initial signal level to use for the gain estimation in the l…

webrtc/modules/audio_processing/level_controller/peak_level_estimator.cc

Index: webrtc/modules/audio_processing/level_controller/peak_level_estimator.cc
diff --git a/webrtc/modules/audio_processing/level_controller/peak_level_estimator.cc b/webrtc/modules/audio_processing/level_controller/peak_level_estimator.cc
index 2ba806c8ee0d15b58c366421aaa1e2b5c20d635b..9d4fe3312cfd57ae0a34b2a542862ec1049eb0d0 100644
--- a/webrtc/modules/audio_processing/level_controller/peak_level_estimator.cc
+++ b/webrtc/modules/audio_processing/level_controller/peak_level_estimator.cc
@@ -13,10 +13,14 @@
 #include <algorithm>
 
 #include "webrtc/modules/audio_processing/audio_buffer.h"
-#include "webrtc/modules/audio_processing/level_controller/lc_constants.h"
 #include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
 
 namespace webrtc {
+namespace {
+
+const float kMinLevel = 30.f;
+
+}  // namespace
 
 PeakLevelEstimator::PeakLevelEstimator() {
   Initialize();
@@ -25,15 +29,26 @@ PeakLevelEstimator::PeakLevelEstimator() {
 PeakLevelEstimator::~PeakLevelEstimator() {}
 
 void PeakLevelEstimator::Initialize() {
-  peak_level_ = kTargetLcPeakLevel;
+  peak_level_ = initial_peak_level_;
   hold_counter_ = 0;
   initialization_phase_ = true;
 }
 
+void PeakLevelEstimator::SetInitialPeakLevel(float level) {
+  RTC_DCHECK_LE(-100.f, level);
+  RTC_DCHECK_GE(0.f, level);
+
+  float linear_level = std::pow(10.f, level / 20.f) * 32768.f;
+
+  // Limit the supplied level to the level range used internally.
+  initial_peak_level_ = std::max(linear_level, kMinLevel);
+  Initialize();
+}
+
 float PeakLevelEstimator::Analyze(SignalClassifier::SignalType signal_type,
                                   float frame_peak_level) {
   if (frame_peak_level == 0) {
-    RTC_DCHECK_LE(30.f, peak_level_);
+    RTC_DCHECK_LE(kMinLevel, peak_level_);
     return peak_level_;
   }
 
@@ -57,7 +72,7 @@ float PeakLevelEstimator::Analyze(SignalClassifier::SignalType signal_type,
     }
   }
 
-  peak_level_ = std::max(peak_level_, 30.f);
+  peak_level_ = std::max(peak_level_, kMinLevel);
 
   return peak_level_;
 }