Further tuning for AEC3 for initial echo suppression and handling of echo path changes

webrtc/modules/audio_processing/aec3/aec_state.cc

 /*
  *  Copyright (c) 2017 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.
  */
 
@@ skipping 63 matching lines @@
 
   *filter_delay =
       num_reliable_delays > 20
           ? rtc::Optional<size_t>(reliable_delays_sum / num_reliable_delays)
           : rtc::Optional<size_t>();
 }
 
 constexpr int kActiveRenderCounterInitial = 50;
 constexpr int kActiveRenderCounterMax = 200;
 constexpr int kEchoPathChangeCounterInitial = 50;
-constexpr int kEchoPathChangeCounterMax = 200;
+constexpr int kEchoPathChangeCounterMax = 3 * 250;
 
 }  // namespace
 
 int AecState::instance_count_ = 0;
 
 AecState::AecState()
     : data_dumper_(
           new ApmDataDumper(rtc::AtomicOps::Increment(&instance_count_))),
       echo_path_change_counter_(kEchoPathChangeCounterInitial),
       active_render_counter_(kActiveRenderCounterInitial) {
@@ skipping 18 matching lines @@
                 &filter_estimate_strength_, &filter_delay_);
   // Compute the externally provided delay in partitions. The truncation is
   // intended here.
   external_delay_ =
       external_delay_samples
           ? rtc::Optional<size_t>(*external_delay_samples / kBlockSize)
           : rtc::Optional<size_t>();
 
   const float x_energy = std::inner_product(x.begin(), x.end(), x.begin(), 0.f);
 
+  active_render_blocks_ =
+      echo_path_variability.AudioPathChanged() ? 0 : active_render_blocks_ + 1;
+
   echo_path_change_counter_ = echo_path_variability.AudioPathChanged()
                                   ? kEchoPathChangeCounterMax
                                   : echo_path_change_counter_ - 1;
   active_render_counter_ = x_energy > 10000.f * kFftLengthBy2
                                ? kActiveRenderCounterMax
                                : active_render_counter_ - 1;
 
   usable_linear_estimate_ = filter_delay_ && echo_path_change_counter_ <= 0;
 
   echo_leakage_detected_ = echo_leakage_detected;
@@ skipping 20 matching lines @@
         [](float a) { return a <= 10.f; });
     headset_detected_ = low_erl_band_count > 20 && noisy_band_count > 20;
 #endif
     headset_detected_ = false;
   } else {
     headset_detected_ = false;
   }
 }
 
 }  // namespace webrtc