AGC: Add a histogram for clipping adjustment

webrtc/modules/audio_processing/agc/agc_manager_direct.cc

 /*
  *  Copyright (c) 2013 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 "webrtc/modules/audio_processing/agc/agc_manager_direct.h"
 
 #include <cmath>
 
 #ifdef WEBRTC_AGC_DEBUG_DUMP
 #include <cstdio>
 #endif
 
 #include "webrtc/base/checks.h"
 #include "webrtc/modules/audio_processing/agc/gain_map_internal.h"
 #include "webrtc/modules/audio_processing/gain_control_impl.h"
 #include "webrtc/modules/include/module_common_types.h"
 #include "webrtc/system_wrappers/include/logging.h"
+#include "webrtc/system_wrappers/include/metrics.h"
 
 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.
@@ skipping 177 matching lines @@
   // maximum. This harsh treatment is an effort to avoid repeated clipped echo
   // events. As compensation for this restriction, the maximum compression
   // gain is increased, through SetMaxLevel().
   float clipped_ratio = agc_->AnalyzePreproc(audio, length);
   if (clipped_ratio > kClippedRatioThreshold) {
     LOG(LS_INFO) << "[agc] Clipping detected. clipped_ratio="
                  << clipped_ratio;
     // Always decrease the maximum level, even if the current level is below
     // threshold.
     SetMaxLevel(std::max(kClippedLevelMin, max_level_ - kClippedLevelStep));
+    RTC_HISTOGRAM_BOOLEAN("WebRTC.Audio.AgcClippingAdjustmentAllowed",
+                          level_ - kClippedLevelStep >= kClippedLevelMin);
     if (level_ > kClippedLevelMin) {
       // 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));
       // Reset the AGC since the level has changed.
       agc_->Reset();
     }
     frames_since_clipped_ = 0;
   }
@@ skipping 204 matching lines @@
     compression_ = new_compression;
     compression_accumulator_ = new_compression;
     if (gctrl_->set_compression_gain_db(compression_) != 0) {
       LOG(LS_ERROR) << "set_compression_gain_db(" << compression_
                     << ") failed.";
     }
   }
 }
 
 }  // namespace webrtc