Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
       3             :  *
       4             :  *  Use of this source code is governed by a BSD-style license
       5             :  *  that can be found in the LICENSE file in the root of the source
       6             :  *  tree. An additional intellectual property rights grant can be found
       7             :  *  in the file PATENTS.  All contributing project authors may
       8             :  *  be found in the AUTHORS file in the root of the source tree.
       9             :  */
      10             : 
      11             : #ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_DELAY_PEAK_DETECTOR_H_
      12             : #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_DELAY_PEAK_DETECTOR_H_
      13             : 
      14             : #include <string.h>  // size_t
      15             : 
      16             : #include <list>
      17             : #include <memory>
      18             : 
      19             : #include "webrtc/base/constructormagic.h"
      20             : #include "webrtc/modules/audio_coding/neteq/tick_timer.h"
      21             : 
      22             : namespace webrtc {
      23             : 
      24           0 : class DelayPeakDetector {
      25             :  public:
      26             :   DelayPeakDetector(const TickTimer* tick_timer);
      27             :   virtual ~DelayPeakDetector();
      28             :   virtual void Reset();
      29             : 
      30             :   // Notifies the DelayPeakDetector of how much audio data is carried in each
      31             :   // packet.
      32             :   virtual void SetPacketAudioLength(int length_ms);
      33             : 
      34             :   // Returns true if peak-mode is active. That is, delay peaks were observed
      35             :   // recently.
      36             :   virtual bool peak_found();
      37             : 
      38             :   // Calculates and returns the maximum delay peak height. Returns -1 if no
      39             :   // delay peaks have been observed recently. The unit is number of packets.
      40             :   virtual int MaxPeakHeight() const;
      41             : 
      42             :   // Calculates and returns the maximum delay peak distance in ms (strictly
      43             :   // larger than 0), or 0 if no delay peaks have been observed recently.
      44             :   virtual uint64_t MaxPeakPeriod() const;
      45             : 
      46             :   // Updates the DelayPeakDetector with a new inter-arrival time (in packets)
      47             :   // and the current target buffer level (needed to decide if a peak is observed
      48             :   // or not). Returns true if peak-mode is active, false if not.
      49             :   virtual bool Update(int inter_arrival_time, int target_level);
      50             : 
      51             :  private:
      52             :   static const size_t kMaxNumPeaks = 8;
      53             :   static const size_t kMinPeaksToTrigger = 2;
      54             :   static const int kPeakHeightMs = 78;
      55             :   static const int kMaxPeakPeriodMs = 10000;
      56             : 
      57             :   typedef struct {
      58             :     uint64_t period_ms;
      59             :     int peak_height_packets;
      60             :   } Peak;
      61             : 
      62             :   bool CheckPeakConditions();
      63             : 
      64             :   std::list<Peak> peak_history_;
      65             :   bool peak_found_;
      66             :   int peak_detection_threshold_;
      67             :   const TickTimer* tick_timer_;
      68             :   std::unique_ptr<TickTimer::Stopwatch> peak_period_stopwatch_;
      69             : 
      70             :   RTC_DISALLOW_COPY_AND_ASSIGN(DelayPeakDetector);
      71             : };
      72             : 
      73             : }  // namespace webrtc
      74             : #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_DELAY_PEAK_DETECTOR_H_