jitter.h

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/*
 * jitter.h
 *
 * Jitter buffer support
 *
 * Open H323 Library
 *
 * Copyright (c) 1999-2001 Equivalence Pty. Ltd.
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Open H323 Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Portions of this code were written with the assisance of funding from
 * Vovida Networks, Inc. http://www.vovida.com.
 *
 * Contributor(s): ______________________________________.
 *
 * $Revision: 27264 $
 * $Author: rjongbloed $
 * $Date: 2012-03-21 19:25:50 -0500 (Wed, 21 Mar 2012) $
 */

#ifndef OPAL_RTP_JITTER_H
#define OPAL_RTP_JITTER_H

#ifdef P_USE_PRAGMA
#pragma interface
#endif

#include <opal/buildopts.h>

#include <rtp/rtp.h>


class RTP_JitterBuffer;
class RTP_JitterBufferAnalyser;



class OpalJitterBuffer : public PSafeObject
{
  PCLASSINFO(OpalJitterBuffer, PSafeObject);

  public:
    OpalJitterBuffer(
      unsigned minJitterDelay, 
      unsigned maxJitterDelay, 
      unsigned timeUnits = 8,  
      PINDEX packetSize = 2048 
    );
    
    virtual ~OpalJitterBuffer();

    void PrintOn(
      ostream & strm
    ) const;

    void SetDelay(
      unsigned minJitterDelay, 
      unsigned maxJitterDelay, 
      PINDEX packetSize = 2048 
    );

    void Reset();

    virtual PBoolean WriteData(
      const RTP_DataFrame & frame,   
      const PTimeInterval & tick = 0 
    );

    virtual PBoolean ReadData(
      RTP_DataFrame & frame,  
      const PTimeInterval & tick = 0 
    );

    DWORD GetCurrentJitterDelay() const { return m_currentJitterDelay; }
    
    DWORD GetMinJitterDelay() const { return m_minJitterDelay; }
    
    DWORD GetMaxJitterDelay() const { return m_maxJitterDelay; }

    unsigned GetTimeUnits() const { return m_timeUnits; }
    
    DWORD GetPacketsTooLate() const { return m_packetsTooLate; }

    DWORD GetBufferOverruns() const { return m_bufferOverruns; }

    DWORD GetMaxConsecutiveMarkerBits() const { return m_maxConsecutiveMarkerBits; }

    void SetMaxConsecutiveMarkerBits(DWORD max) { m_maxConsecutiveMarkerBits = max; }

  protected:
    DWORD CalculateRequiredTimestamp(DWORD playOutTimestamp) const;
    bool AdjustCurrentJitterDelay(int delta);

    unsigned m_timeUnits;
    PINDEX   m_packetSize;
    DWORD    m_minJitterDelay;      
    DWORD    m_maxJitterDelay;      
    int      m_jitterGrowTime;      
    DWORD    m_jitterShrinkPeriod;  

    int      m_jitterShrinkTime;    
    DWORD    m_silenceShrinkPeriod; 
    int      m_silenceShrinkTime;   
    DWORD    m_jitterDriftPeriod;

    int      m_currentJitterDelay;
    DWORD    m_packetsTooLate;
    DWORD    m_bufferOverruns;
    DWORD    m_consecutiveMarkerBits;
    DWORD    m_maxConsecutiveMarkerBits;
    DWORD    m_consecutiveLatePackets;

    DWORD    m_averageFrameTime;
    DWORD    m_lastTimestamp;
    DWORD    m_lastSyncSource;
    DWORD    m_bufferFilledTime;
    DWORD    m_bufferLowTime;
    DWORD    m_bufferEmptiedTime;
    int      m_timestampDelta;

    enum {
      e_SynchronisationStart,
      e_SynchronisationFill,
      e_SynchronisationShrink,
      e_SynchronisationDone
    } m_synchronisationState;

    typedef std::map<DWORD, RTP_DataFrame> FrameMap;
    FrameMap m_frames;
    PMutex   m_bufferMutex;

    RTP_JitterBufferAnalyser * m_analyser;
};


class OpalJitterBufferThread : public OpalJitterBuffer
{
    PCLASSINFO(OpalJitterBufferThread, OpalJitterBuffer);
 public:
    OpalJitterBufferThread(
      unsigned minJitterDelay, 
      unsigned maxJitterDelay, 
      unsigned timeUnits = 8,  
      PINDEX packetSize = 2048 
    );
    ~OpalJitterBufferThread();

    virtual PBoolean ReadData(
      RTP_DataFrame & frame   
    );

    virtual PBoolean OnReadPacket(
      RTP_DataFrame & frame   
    ) = 0;

  protected:
    PDECLARE_NOTIFIER(PThread, OpalJitterBufferThread, JitterThreadMain);

    void StartThread();

    void WaitForThreadTermination();

    PThread * m_jitterThread;
    bool      m_running;
};



class RTP_JitterBuffer : public OpalJitterBufferThread
{
    PCLASSINFO(RTP_JitterBuffer, OpalJitterBufferThread);
 public:
    RTP_JitterBuffer(
      RTP_Session & session,   
      unsigned minJitterDelay, 
      unsigned maxJitterDelay, 
      unsigned timeUnits = 8,  
      PINDEX packetSize = 2048 
    );
    ~RTP_JitterBuffer();

    virtual PBoolean OnReadPacket(
      RTP_DataFrame & frame   
    );

 protected:
   RTP_Session & m_session;
};

#endif // OPAL_RTP_JITTER_H