Add log message to help analyze why echo likelihood > 1.1

webrtc/modules/audio_processing/residual_echo_detector.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.
  */
 
 #include "webrtc/modules/audio_processing/residual_echo_detector.h"
 
 #include <algorithm>
 #include <numeric>
 
 #include "webrtc/base/atomicops.h"
+#include "webrtc/base/logging.h"
 #include "webrtc/modules/audio_processing/audio_buffer.h"
 #include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
 #include "webrtc/system_wrappers/include/metrics.h"
 
 namespace {
 
 float Power(rtc::ArrayView<const float> input) {
   if (input.size() == 0) {
     return 0.f;
   }
@@ skipping 80 matching lines @@
   // Get the next capture value, update capture statistics and add the relevant
   // values to the buffers.
   const float capture_power = Power(capture_audio);
   capture_statistics_.Update(capture_power);
   const float capture_mean = capture_statistics_.mean();
   const float capture_std_deviation = capture_statistics_.std_deviation();
 
   // Update the covariance values and determine the new echo likelihood.
   echo_likelihood_ = 0.f;
   size_t read_index = next_insertion_index_;
+
+  int best_delay = -1;
   for (size_t delay = 0; delay < covariances_.size(); ++delay) {
     RTC_DCHECK_LT(read_index, render_power_.size());
     covariances_[delay].Update(capture_power, capture_mean,
                                capture_std_deviation, render_power_[read_index],
                                render_power_mean_[read_index],
                                render_power_std_dev_[read_index]);
-    echo_likelihood_ = std::max(
-        echo_likelihood_, covariances_[delay].normalized_cross_correlation());
+    read_index = read_index > 0 ? read_index - 1 : kLookbackFrames - 1;
 
-    read_index = read_index > 0 ? read_index - 1 : kLookbackFrames - 1;
+    if (covariances_[delay].normalized_cross_correlation() > echo_likelihood_) {
+      echo_likelihood_ = covariances_[delay].normalized_cross_correlation();
+      best_delay = static_cast<int>(delay);
+    }
+  }
+  // This is a temporary log message to help find the underlying cause for echo
+  // likelihoods > 1.0.
+  // TODO(ivoc): Remove once the issue is resolved.
+  if (echo_likelihood_ > 1.1f) {
+    // Make sure we don't spam the log.
+    if (log_counter_ < 5 && best_delay != -1) {
+      size_t read_index = kLookbackFrames + next_insertion_index_ - best_delay;
+      if (read_index >= kLookbackFrames) {
+        read_index -= kLookbackFrames;
+      }
+      RTC_DCHECK_LT(read_index, render_power_.size());
+      LOG_F(LS_ERROR) << "Echo detector internal state: {"
+                      << "Echo likelihood: " << echo_likelihood_
+                      << ", Best Delay: " << best_delay << ", Covariance: "
+                      << covariances_[best_delay].covariance()
+                      << ", Last capture power: " << capture_power
+                      << ", Capture mean: " << capture_mean
+                      << ", Capture_standard deviation: "
+                      << capture_std_deviation
+                      << ", Last render power: " << render_power_[read_index]
+                      << ", Render mean: " << render_power_mean_[read_index]
+                      << ", Render standard deviation: "
+                      << render_power_std_dev_[read_index]
+                      << ", Reliability: " << reliability_ << "}";
+      log_counter_++;
+    }
   }
   RTC_DCHECK_LT(echo_likelihood_, 1.1f);
+
   reliability_ = (1.0f - kAlpha) * reliability_ + kAlpha * 1.0f;
   echo_likelihood_ *= reliability_;
   // This is a temporary fix to prevent echo likelihood values > 1.0.
   // TODO(ivoc): Find the root cause of this issue and fix it.
   echo_likelihood_ = std::min(echo_likelihood_, 1.0f);
   int echo_percentage = static_cast<int>(echo_likelihood_ * 100);
   RTC_HISTOGRAM_COUNTS("WebRTC.Audio.ResidualEchoDetector.EchoLikelihood",
                        echo_percentage, 0, 100, 100 /* number of bins */);
 
   // Update the buffer of recent likelihood values.
@@ skipping 23 matching lines @@
 
 void ResidualEchoDetector::PackRenderAudioBuffer(
     AudioBuffer* audio,
     std::vector<float>* packed_buffer) {
   packed_buffer->clear();
   packed_buffer->insert(packed_buffer->end(), audio->channels_f()[0],
                         audio->channels_f()[0] + audio->num_frames());
 }
 
 }  // namespace webrtc