AGC: Route clipping parameter from webrtc::Config to AGC

webrtc/modules/audio_processing/agc/agc_manager_direct.cc

Index: webrtc/modules/audio_processing/agc/agc_manager_direct.cc
diff --git a/webrtc/modules/audio_processing/agc/agc_manager_direct.cc b/webrtc/modules/audio_processing/agc/agc_manager_direct.cc
index f8fc310c57569aa28dab3a1d440bcc09292f72e7..70a0e1f2b2d1339db45ea4e8b51e2b04310f5374 100644
--- a/webrtc/modules/audio_processing/agc/agc_manager_direct.cc
+++ b/webrtc/modules/audio_processing/agc/agc_manager_direct.cc
@@ -27,8 +27,6 @@ namespace webrtc {
 
 namespace {
 
-// Lowest the microphone level can be lowered due to clipping.
-const int kClippedLevelMin = 170;
 // Amount the microphone level is lowered with every clipping event.
 const int kClippedLevelStep = 15;
 // Proportion of clipped samples required to declare a clipping event.
@@ -115,7 +113,8 @@ class DebugFile {
 
 AgcManagerDirect::AgcManagerDirect(GainControl* gctrl,
                                    VolumeCallbacks* volume_callbacks,
-                                   int startup_min_level)
+                                   int startup_min_level,
+                                   int clipped_level_min)
     : agc_(new Agc()),
       gctrl_(gctrl),
       volume_callbacks_(volume_callbacks),
@@ -130,14 +129,15 @@ AgcManagerDirect::AgcManagerDirect(GainControl* gctrl,
       check_volume_on_next_process_(true),  // Check at startup.
       startup_(true),
       startup_min_level_(ClampLevel(startup_min_level)),
+      clipped_level_min_(clipped_level_min),
       file_preproc_(new DebugFile("agc_preproc.pcm")),
-      file_postproc_(new DebugFile("agc_postproc.pcm")) {
-}
+      file_postproc_(new DebugFile("agc_postproc.pcm")) {}
 
 AgcManagerDirect::AgcManagerDirect(Agc* agc,
                                    GainControl* gctrl,
                                    VolumeCallbacks* volume_callbacks,
-                                   int startup_min_level)
+                                   int startup_min_level,
+                                   int clipped_level_min)
     : agc_(agc),
       gctrl_(gctrl),
       volume_callbacks_(volume_callbacks),
@@ -152,9 +152,9 @@ AgcManagerDirect::AgcManagerDirect(Agc* agc,
       check_volume_on_next_process_(true),  // Check at startup.
       startup_(true),
       startup_min_level_(ClampLevel(startup_min_level)),
+      clipped_level_min_(clipped_level_min),
       file_preproc_(new DebugFile("agc_preproc.pcm")),
-      file_postproc_(new DebugFile("agc_postproc.pcm")) {
-}
+      file_postproc_(new DebugFile("agc_postproc.pcm")) {}
 
 AgcManagerDirect::~AgcManagerDirect() {}
 
@@ -218,14 +218,14 @@ void AgcManagerDirect::AnalyzePreProcess(int16_t* audio,
                  << clipped_ratio;
     // Always decrease the maximum level, even if the current level is below
     // threshold.
-    SetMaxLevel(std::max(kClippedLevelMin, max_level_ - kClippedLevelStep));
+    SetMaxLevel(std::max(clipped_level_min_, max_level_ - kClippedLevelStep));
     RTC_HISTOGRAM_BOOLEAN("WebRTC.Audio.AgcClippingAdjustmentAllowed",
-                          level_ - kClippedLevelStep >= kClippedLevelMin);
-    if (level_ > kClippedLevelMin) {
+                          level_ - kClippedLevelStep >= clipped_level_min_);
+    if (level_ > clipped_level_min_) {
       // Don't try to adjust the level if we're already below the limit. As
       // a consequence, if the user has brought the level above the limit, we
       // will still not react until the postproc updates the level.
-      SetLevel(std::max(kClippedLevelMin, level_ - kClippedLevelStep));
+      SetLevel(std::max(clipped_level_min_, level_ - kClippedLevelStep));
       // Reset the AGC since the level has changed.
       agc_->Reset();
     }
@@ -301,13 +301,15 @@ void AgcManagerDirect::SetLevel(int new_level) {
 }
 
 void AgcManagerDirect::SetMaxLevel(int level) {
-  RTC_DCHECK_GE(level, kClippedLevelMin);
+  RTC_DCHECK_GE(level, clipped_level_min_);
   max_level_ = level;
   // Scale the |kSurplusCompressionGain| linearly across the restricted
   // level range.
-  max_compression_gain_ = kMaxCompressionGain + std::floor(
-      (1.f * kMaxMicLevel - max_level_) / (kMaxMicLevel - kClippedLevelMin) *
-      kSurplusCompressionGain + 0.5f);
+  max_compression_gain_ =
+      kMaxCompressionGain + std::floor((1.f * kMaxMicLevel - max_level_) /
+                                           (kMaxMicLevel - clipped_level_min_) *
+                                           kSurplusCompressionGain +
+                                       0.5f);
   LOG(LS_INFO) << "[agc] max_level_=" << max_level_
                << ", max_compression_gain_="  << max_compression_gain_;
 }