NetEq: Fix a bug in DelayPeakDetector causing asserts to trigger

webrtc/modules/audio_coding/neteq/delay_peak_detector.cc

 /*
  *  Copyright (c) 2012 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 59 matching lines @@
   return max_period_element->period_ms;
 }
 
 bool DelayPeakDetector::Update(int inter_arrival_time, int target_level) {
   if (inter_arrival_time > target_level + peak_detection_threshold_ ||
       inter_arrival_time > 2 * target_level) {
     // A delay peak is observed.
     if (!peak_period_stopwatch_) {
       // This is the first peak. Reset the period counter.
       peak_period_stopwatch_ = tick_timer_->GetNewStopwatch();
-    } else if (peak_period_stopwatch_->ElapsedMs() <= kMaxPeakPeriodMs) {
-      // This is not the first peak, and the period is valid.
-      // Store peak data in the vector.
-      Peak peak_data;
-      peak_data.period_ms = peak_period_stopwatch_->ElapsedMs();
-      peak_data.peak_height_packets = inter_arrival_time;
-      peak_history_.push_back(peak_data);
-      while (peak_history_.size() > kMaxNumPeaks) {
-        // Delete the oldest data point.
-        peak_history_.pop_front();
+    } else if (peak_period_stopwatch_->ElapsedMs() > 0) {
+      if (peak_period_stopwatch_->ElapsedMs() <= kMaxPeakPeriodMs) {
+        // This is not the first peak, and the period is valid.
+        // Store peak data in the vector.
+        Peak peak_data;
+        peak_data.period_ms = peak_period_stopwatch_->ElapsedMs();
+        peak_data.peak_height_packets = inter_arrival_time;
+        peak_history_.push_back(peak_data);
+        while (peak_history_.size() > kMaxNumPeaks) {
+          // Delete the oldest data point.
+          peak_history_.pop_front();
+        }
+        peak_period_stopwatch_ = tick_timer_->GetNewStopwatch();
+      } else if (peak_period_stopwatch_->ElapsedMs() <= 2 * kMaxPeakPeriodMs) {
+        // Invalid peak due to too long period. Reset period counter and start
+        // looking for next peak.
+        peak_period_stopwatch_ = tick_timer_->GetNewStopwatch();
+      } else {
+        // More than 2 times the maximum period has elapsed since the last peak
+        // was registered. It seams that the network conditions have changed.
+        // Reset the peak statistics.
+        Reset();
       }
-      peak_period_stopwatch_ = tick_timer_->GetNewStopwatch();
-    } else if (peak_period_stopwatch_->ElapsedMs() <= 2 * kMaxPeakPeriodMs) {
-      // Invalid peak due to too long period. Reset period counter and start
-      // looking for next peak.
-      peak_period_stopwatch_ = tick_timer_->GetNewStopwatch();
-    } else {
-      // More than 2 times the maximum period has elapsed since the last peak
-      // was registered. It seams that the network conditions have changed.
-      // Reset the peak statistics.
-      Reset();
     }
   }
   return CheckPeakConditions();
 }
 
 bool DelayPeakDetector::CheckPeakConditions() {
   size_t s = peak_history_.size();
   if (s >= kMinPeaksToTrigger &&
       peak_period_stopwatch_->ElapsedMs() <= 2 * MaxPeakPeriod()) {
     peak_found_ = true;
   } else {
     peak_found_ = false;
   }
   return peak_found_;
 }
 }  // namespace webrtc