www.pudn.com > openh323-v1_15_1-src.zip > jitter.h
/*
* jitter.h
*
* Jitter buffer support
*
* Open H323 Library
*
* Copyright (c) 1999-2000 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): ______________________________________.
*
* $Log: jitter.h,v $
* Revision 1.13 2003/10/28 22:38:31 dereksmithies
* Rework of jitter buffer. Many thanks to Henry Harrison of Alice Street.
*
* Revision 1.12ACC1.0 6th October 2003 henryh
* Complete change to adaptive algorithm
*
* Revision 1.12 2002/10/31 00:32:39 robertj
* Enhanced jitter buffer system so operates dynamically between minimum and
* maximum values. Altered API to assure app writers note the change!
*
* Revision 1.11 2002/09/16 01:14:15 robertj
* Added #define so can select if #pragma interface/implementation is used on
* platform basis (eg MacOS) rather than compiler, thanks Robert Monaghan.
*
* Revision 1.10 2002/09/03 05:40:18 robertj
* Normalised the multi-include header prevention ifdef/define symbol.
* Added buffer reset on excess buffer overruns.
* Added ability to get buffer overruns for statistics display.
*
* Revision 1.9 2002/08/05 10:03:47 robertj
* Cosmetic changes to normalise the usage of pragma interface/implementation.
*
* Revision 1.8 2001/09/11 00:21:21 robertj
* Fixed missing stack sizes in endpoint for cleaner thread and jitter thread.
*
* Revision 1.7 2001/02/09 05:16:24 robertj
* Added #pragma interface for GNU C++.
*
* Revision 1.6 2000/05/25 02:26:12 robertj
* Added ignore of marker bits on broken clients that sets it on every RTP packet.
*
* Revision 1.5 2000/05/04 11:49:21 robertj
* Added Packets Too Late statistics, requiring major rearrangement of jitter buffer code.
*
* Revision 1.4 2000/05/02 04:32:24 robertj
* Fixed copyright notice comment.
*
* Revision 1.3 2000/04/30 03:56:14 robertj
* More instrumentation to analyse jitter buffer operation.
*
* Revision 1.2 2000/03/20 20:51:13 robertj
* Fixed possible buffer overrun problem in RTP_DataFrames
*
* Revision 1.1 1999/12/23 23:02:35 robertj
* File reorganision for separating RTP from H.323 and creation of LID for VPB support.
*
*/
#ifndef __OPAL_JITTER_H
#define __OPAL_JITTER_H
#ifdef P_USE_PRAGMA
#pragma interface
#endif
#include "rtp.h"
class RTP_JitterBufferAnalyser;
///////////////////////////////////////////////////////////////////////////////
class RTP_JitterBuffer : public PThread
{
PCLASSINFO(RTP_JitterBuffer, PThread);
public:
RTP_JitterBuffer(
RTP_Session & session, /// Associated RTP session tor ead data from
unsigned minJitterDelay, /// Minimum delay in RTP timestamp units
unsigned maxJitterDelay, /// Maximum delay in RTP timestamp units
PINDEX stackSize = 30000 /// Stack size for jitter thread
);
~RTP_JitterBuffer();
// PINDEX GetSize() const { return bufferSize; }
/**Set the maximum delay the jitter buffer will operate to.
*/
void SetDelay(
unsigned minJitterDelay, /// Minimum delay in RTP timestamp units
unsigned maxJitterDelay /// Maximum delay in RTP timestamp units
);
void UseImmediateReduction(BOOL state) { doJitterReductionImmediately = state; }
/**Read a data frame from the RTP channel.
Any control frames received are dispatched to callbacks and are not
returned by this function. It will block until a data frame is
available or an error occurs.
*/
virtual BOOL ReadData(
DWORD timestamp, /// Timestamp to read from buffer.
RTP_DataFrame & frame /// Frame read from the RTP session
);
/**Get current delay for jitter buffer.
*/
DWORD GetJitterTime() const { return currentJitterTime; }
/**Get total number received packets too late to go into jitter buffer.
*/
DWORD GetPacketsTooLate() const { return packetsTooLate; }
/**Get total number received packets that overran the jitter buffer.
*/
DWORD GetBufferOverruns() const { return bufferOverruns; }
/**Get maximum consecutive marker bits before buffer starts to ignore them.
*/
DWORD GetMaxConsecutiveMarkerBits() const { return maxConsecutiveMarkerBits; }
/**Set maximum consecutive marker bits before buffer starts to ignore them.
*/
void SetMaxConsecutiveMarkerBits(DWORD max) { maxConsecutiveMarkerBits = max; }
protected:
virtual void Main();
class Entry : public RTP_DataFrame
{
public:
Entry * next;
Entry * prev;
PTimeInterval tick;
};
RTP_Session & session;
PINDEX bufferSize;
DWORD minJitterTime;
DWORD maxJitterTime;
DWORD maxConsecutiveMarkerBits;
unsigned currentDepth;
DWORD currentJitterTime;
DWORD packetsTooLate;
unsigned bufferOverruns;
unsigned consecutiveBufferOverruns;
DWORD consecutiveMarkerBits;
PTimeInterval consecutiveEarlyPacketStartTime;
DWORD lastWriteTimestamp;
PTimeInterval lastWriteTick;
DWORD jitterCalc;
DWORD targetJitterTime;
unsigned jitterCalcPacketCount;
BOOL doJitterReductionImmediately;
BOOL doneFreeTrash;
Entry * oldestFrame;
Entry * newestFrame;
Entry * freeFrames;
Entry * currentWriteFrame;
PMutex bufferMutex;
BOOL shuttingDown;
BOOL preBuffering;
BOOL doneFirstWrite;
RTP_JitterBufferAnalyser * analyser;
};
#endif // __OPAL_JITTER_H
/////////////////////////////////////////////////////////////////////////////