rtp.cxx

mgcp协议源代码。支持多种编码：g711

/*
 * rtp.cxx
 *
 * RTP protocol handler
 *
 * Open H323 Library
 *
 * Copyright (c) 1998-2000 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: rtp.cxx,v $
 * Revision 1.46  2000/05/30 10:35:41  robertj
 * Fixed GNU compiler warning.
 *
 * Revision 1.45  2000/05/30 06:52:26  robertj
 * Fixed problem with Cisco restarting sequence numbers when changing H.323 logical channels.
 *
 * Revision 1.44  2000/05/23 12:57:37  robertj
 * Added ability to change IP Type Of Service code from applications.
 *
 * Revision 1.43  2000/05/12 00:27:35  robertj
 * Fixed bug in UseSession() that caused asserts on BSD and possible race condition everywhere.
 *
 * Revision 1.42  2000/05/04 11:52:35  robertj
 * Added Packets Too Late statistics, requiring major rearrangement of jitter
 *    buffer code, not also changes semantics of codec Write() function slightly.
 *
 * Revision 1.41  2000/05/02 04:32:27  robertj
 * Fixed copyright notice comment.
 *
 * Revision 1.40  2000/05/01 01:01:49  robertj
 * Added flag for what to do with out of orer packets (use if jitter, don't if not).
 *
 * Revision 1.39  2000/04/30 03:55:09  robertj
 * Improved the RTCP messages, epecially reports
 *
 * Revision 1.38  2000/04/28 12:56:39  robertj
 * Fixed transmission of SDES record in RTCP channel.
 *
 * Revision 1.37  2000/04/19 01:50:05  robertj
 * Improved debugging messages.
 *
 * Revision 1.36  2000/04/13 18:07:39  robertj
 * Fixed missing mutex release causing possible deadlocks.
 *
 * Revision 1.35  2000/04/10 17:40:05  robertj
 * Fixed debug output of RTP payload types to allow for unknown numbers.
 *
 * Revision 1.34  2000/04/05 04:09:24  robertj
 * Fixed portability problem with max() macro.
 *
 * Revision 1.33  2000/04/05 03:17:32  robertj
 * Added more RTP statistics gathering and H.245 round trip delay calculation.
 *
 * Revision 1.32  2000/04/03 18:15:44  robertj
 * Added "fractional" part of RTCP status NTP timestamp field.
 *
 * Revision 1.31  2000/03/23 02:54:57  robertj
 * Added sending of SDES control packets.
 *
 * Revision 1.30  2000/03/20 20:53:42  robertj
 * Fixed problem with being able to reopen for reading an RTP_Session (Cisco compatibilty)
 *
 * Revision 1.29  2000/03/04 12:32:23  robertj
 * Added setting of TOS field in IP header to get poor mans QoS on some routers.
 *
 * Revision 1.28  2000/02/29 13:00:13  robertj
 * Added extra statistic display for RTP packets out of order.
 *
 * Revision 1.27  2000/02/29 02:13:56  robertj
 * Fixed RTP receive of both control and data, ignores ECONNRESET/ECONNREFUSED errors.
 *
 * Revision 1.26  2000/02/27 10:56:24  robertj
 * Fixed error in code allowing non-consecutive RTP port numbers coming from broken stacks, thanks Vassili Leonov.
 *
 * Revision 1.25  2000/02/17 12:07:44  robertj
 * Used ne wPWLib random number generator after finding major problem in MSVC rand().
 *
 * Revision 1.24  2000/01/29 07:10:20  robertj
 * Fixed problem with RTP transmit to host that is not yet ready causing the
 *   receive side to die with ECONNRESET, thanks Ian MacDonald
 *
 * Revision 1.23  2000/01/20 05:57:46  robertj
 * Added extra flexibility in receiving incorrectly formed OpenLogicalChannel PDU's
 *
 * Revision 1.22  2000/01/14 00:31:40  robertj
 * Bug fix for RTP port allocation (MSVC optimised version), Thanks to Ian MacDonald.
 *
 * Revision 1.21  1999/12/30 09:14:49  robertj
 * Changed payload type functions to use enum.
 *
 * Revision 1.20  1999/12/23 23:02:36  robertj
 * File reorganision for separating RTP from H.323 and creation of LID for VPB support.
 *
 * Revision 1.19  1999/11/29 04:50:11  robertj
 * Added adaptive threshold calculation to silence detection.
 *
 * Revision 1.18  1999/11/22 00:09:59  robertj
 * Fixed error in RTP transmit rewrite for ternary state, didn't transmit at all!
 *
 * Revision 1.17  1999/11/20 05:35:48  robertj
 * Fixed possibly I/O block in RTP read loops.
 *
 * Revision 1.16  1999/11/19 13:13:31  robertj
 * Fixed Windows 95 compatibility issue in shutdown of RTP reading.
 *
 * Revision 1.15  1999/11/19 10:23:16  robertj
 * Fixed local binding of socket to correct address on multi-homes systems.
 *
 * Revision 1.14  1999/11/19 09:17:15  robertj
 * Fixed problems with aycnhronous shut down of logical channels.
 *
 * Revision 1.13  1999/11/17 03:49:51  robertj
 * Added RTP statistics display.
 *
 * Revision 1.12  1999/11/14 11:41:07  robertj
 * Added access functions to RTP statistics.
 *
 * Revision 1.11  1999/10/18 23:55:11  robertj
 * Fixed bug in setting contributing sources, length put into wrong spot in PDU header
 *
 * Revision 1.10  1999/09/21 14:10:04  robertj
 * Removed warnings when no tracing enabled.
 *
 * Revision 1.9  1999/09/05 00:58:37  robertj
 * Removed requirement that OpenLogicalChannalAck sessionId match original OLC.
 *
 * Revision 1.8  1999/09/03 02:17:50  robertj
 * Added more debugging
 *
 * Revision 1.7  1999/08/31 12:34:19  robertj
 * Added gatekeeper support.
 *
 * Revision 1.6  1999/07/16 02:13:54  robertj
 * Slowed down the control channel statistics packets.
 *
 * Revision 1.5  1999/07/13 09:53:24  robertj
 * Fixed some problems with jitter buffer and added more debugging.
 *
 * Revision 1.4  1999/07/09 06:09:52  robertj
 * Major implementation. An ENORMOUS amount of stuff added everywhere.
 *
 * Revision 1.3  1999/06/22 13:49:40  robertj
 * Added GSM support and further RTP protocol enhancements.
 *
 * Revision 1.2  1999/06/14 08:42:52  robertj
 * Fixed bug in dropped packets display was negative.
 *
 * Revision 1.1  1999/06/14 06:12:25  robertj
 * Changes for using RTP sessions correctly in H323 Logical Channel context
 *
 */

#include <ptlib.h>
#include <ptclib/random.h>
#include "rtp.h"
#include "jitter.h"


#define new PNEW

#if !PTRACING // Stuff to remove unised parameters warning
#define PTRACE_sender
#define PTRACE_reports
#define PTRACE_count
#define PTRACE_src
#define PTRACE_description
#define PTRACE_reason
#define PTRACE_type
#define PTRACE_subtype
#define PTRACE_size
#define PTRACE_name
#define PTRACE_port
#endif


const unsigned SecondsFrom1900to1970 = (70*365+17)*24*60*60U;

#define UDP_BUFFER_SIZE 32768


/////////////////////////////////////////////////////////////////////////////

RTP_DataFrame::RTP_DataFrame(PINDEX sz)
  : PBYTEArray(12+sz)
{
  payloadSize = sz;
  theArray[0] = '\x80';
}


void RTP_DataFrame::SetExtension(BOOL ext)
{
  if (ext)
    theArray[0] |= 0x10;
  else
    theArray[0] &= 0xef;
}


void RTP_DataFrame::SetMarker(BOOL m)
{
  if (m)
    theArray[1] |= 0x80;
  else
    theArray[1] &= 0x7f;
}


void RTP_DataFrame::SetPayloadType(PayloadTypes t)
{
  PAssert(t <= 0x7f, PInvalidParameter);

  theArray[1] &= 0x80;
  theArray[1] |= t;
}


DWORD RTP_DataFrame::GetContribSource(PINDEX idx) const
{
  PAssert(idx < GetContribSrcCount(), PInvalidParameter);
  return ((PUInt32b *)&theArray[12])[idx];
}


void RTP_DataFrame::SetContribSource(PINDEX idx, DWORD src)
{
  PAssert(idx <= 15, PInvalidParameter);

  if (idx >= GetContribSrcCount()) {
    BYTE * oldPayload = GetPayloadPtr();
    theArray[0] &= 0xf0;
    theArray[0] |= idx+1;
    SetSize(GetHeaderSize()+payloadSize);
    memmove(GetPayloadPtr(), oldPayload, payloadSize);
  }

  ((PUInt32b *)&theArray[12])[idx] = src;
}


BOOL RTP_DataFrame::SetPayloadSize(PINDEX sz)
{
  payloadSize = sz;
  return SetMinSize(GetHeaderSize()+payloadSize);
}


#if PTRACING
static const char * const PayloadTypesNames[RTP_DataFrame::LastKnownPayloadType] = {
  "PCMU",
  "FS1016",
  "G721",
  "GSM",
  "G7231",
  "DVI4_8k",
  "DVI4_16k",
  "LPC",
  "PCMA",
  "G722",
  "L16_Stereo",
  "L16_Mono",
  "G723",
  "CN",
  "MPA",
  "G728",
  "DVI4_11k",
  "DVI4_22k",
  "G729",
  "", "", "", "", "", "",
  "CelB",
  "JPEG",
  "", "", "", "",
  "H261",
  "MPV",
  "MP2T",
  "H263"
};

ostream & operator<<(ostream & o, RTP_DataFrame::PayloadTypes t)
{
  if ((PINDEX)t < PARRAYSIZE(PayloadTypesNames))
    o << PayloadTypesNames[t];
  else
    o << "PayloadType(" << (int)t << ')';
  return o;
}

#endif


/////////////////////////////////////////////////////////////////////////////

RTP_ControlFrame::RTP_ControlFrame(PINDEX sz)
{
  SetPayloadSize(sz);
  theArray[0] = '\x80';
}


void RTP_ControlFrame::SetCount(unsigned count)
{
  PAssert(count < 32, PInvalidParameter);
  theArray[0] &= 0xe0;
  theArray[0] |= count;
}


void RTP_ControlFrame::SetPayloadType(unsigned t)
{
  PAssert(t < 256, PInvalidParameter);
  theArray[1] = (BYTE)t;
}


void RTP_ControlFrame::SetPayloadSize(PINDEX sz)
{
  sz = (sz+3)/4;
  PAssert(sz <= 0xffff, PInvalidParameter);

  SetMinSize(4*(sz+1));
  *(PUInt16b *)&theArray[2] = (WORD)sz;
}


RTP_ControlFrame::SourceDescription & RTP_ControlFrame::AddSourceDescription(DWORD src)
{
  SetPayloadType(RTP_ControlFrame::e_SourceDescription);

  PINDEX index = GetCount();
  SetCount(index+1);

  PINDEX originalPayloadSize = index != 0 ? GetPayloadSize() : 0;
  SetPayloadSize(originalPayloadSize+sizeof(SourceDescription));
  SourceDescription & sdes = *(SourceDescription *)(GetPayloadPtr()+originalPayloadSize);
  sdes.src = src;
  sdes.item[0].type = e_END;
  return sdes;
}


RTP_ControlFrame::SourceDescription::Item &
        RTP_ControlFrame::AddSourceDescriptionItem(SourceDescription & sdes,
                                                   unsigned type,
                                                   const PString & data)
{
  PINDEX dataLength = data.GetLength();
  SetPayloadSize(GetPayloadSize()+sizeof(SourceDescription::Item)+dataLength-1);

  SourceDescription::Item * item = sdes.item;
  while (item->type != e_END)
    item = item->GetNextItem();

  item->type = (BYTE)type;
  item->length = (BYTE)dataLength;
  memcpy(item->data, (const char *)data, item->length);

  item->GetNextItem()->type = e_END;
  return *item;
}


void RTP_ControlFrame::ReceiverReport::SetLostPackets(unsigned packets)
{
  lost[0] = (BYTE)(packets >> 16);
  lost[1] = (BYTE)(packets >> 8);
  lost[2] = (BYTE)packets;
}


/////////////////////////////////////////////////////////////////////////////

void RTP_UserData::OnTxStatistics(const RTP_Session & /*session*/) const
{
}


void RTP_UserData::OnRxStatistics(const RTP_Session & /*session*/) const
{
}


/////////////////////////////////////////////////////////////////////////////

RTP_Session::RTP_Session(unsigned id, RTP_UserData * data)
{
  PAssert(id > 0 && id < 256, PInvalidParameter);
  sessionID = (BYTE)id;

  referenceCount = 1;
  userData = data;
  jitter = NULL;

  expectedSequenceNumber = 0;
  lastSentSequenceNumber = (WORD)PRandom::Number();

  syncSourceOut = PRandom::Number();
  ignoreOutOfOrderPackets = TRUE;