xref: /dports/net/opal/opal-3.10.10/src/opal/connection.cxx

/*
 * connection.cxx
 *
 * Connection abstraction
 *
 * Open Phone Abstraction Library (OPAL)
 * Formally known as the Open H323 project.
 *
 * Copyright (c) 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 Phone Abstraction Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Contributor(s): ______________________________________.
 *
 * $Revision: 28445 $
 * $Author: rjongbloed $
 * $Date: 2012-10-02 20:11:02 -0500 (Tue, 02 Oct 2012) $
 */

#include <ptlib.h>

#ifdef __GNUC__
#pragma implementation "connection.h"
#endif

#include <opal/buildopts.h>

#include <opal/connection.h>

#include <opal/manager.h>
#include <opal/endpoint.h>
#include <opal/call.h>
#include <opal/transcoders.h>
#include <opal/patch.h>
#include <codec/silencedetect.h>
#include <codec/echocancel.h>
#include <codec/rfc2833.h>
#include <codec/g711codec.h>
#include <codec/vidcodec.h>
#include <rtp/rtp.h>
#include <t120/t120proto.h>
#include <t38/t38proto.h>
#include <ptclib/url.h>

#if OPAL_HAS_IM
#include <im/rfc4103.h>
#if OPAL_SIP
#include <im/sipim.h>
#include <sip/sipcon.h>
#endif
#endif

#define new PNEW


#if PTRACING
ostream & operator<<(ostream & out, OpalConnection::Phases phase)
{
  static const char * const names[OpalConnection::NumPhases] = {
    "UninitialisedPhase",
    "SetUpPhase",
    "ProceedingPhase",
    "AlertingPhase",
    "ConnectedPhase",
    "EstablishedPhase",
    "ForwardingPhase",
    "ReleasingPhase",
    "ReleasedPhase"
  };
  return out << names[phase];
}


ostream & operator<<(ostream & out, OpalConnection::CallEndReason reason)
{
  const char * const names[OpalConnection::NumCallEndReasons] = {
    "EndedByLocalUser",         /// Local endpoint application cleared call
    "EndedByNoAccept",          /// Local endpoint did not accept call OnIncomingCall()=PFalse
    "EndedByAnswerDenied",      /// Local endpoint declined to answer call
    "EndedByRemoteUser",        /// Remote endpoint application cleared call
    "EndedByRefusal",           /// Remote endpoint refused call
    "EndedByNoAnswer",          /// Remote endpoint did not answer in required time
    "EndedByCallerAbort",       /// Remote endpoint stopped calling
    "EndedByTransportFail",     /// Transport error cleared call
    "EndedByConnectFail",       /// Transport connection failed to establish call
    "EndedByGatekeeper",        /// Gatekeeper has cleared call
    "EndedByNoUser",            /// Call failed as could not find user (in GK)
    "EndedByNoBandwidth",       /// Call failed as could not get enough bandwidth
    "EndedByCapabilityExchange",/// Could not find common capabilities
    "EndedByCallForwarded",     /// Call was forwarded using FACILITY message
    "EndedBySecurityDenial",    /// Call failed a security check and was ended
    "EndedByLocalBusy",         /// Local endpoint busy
    "EndedByLocalCongestion",   /// Local endpoint congested
    "EndedByRemoteBusy",        /// Remote endpoint busy
    "EndedByRemoteCongestion",  /// Remote endpoint congested
    "EndedByUnreachable",       /// Could not reach the remote party
    "EndedByNoEndPoint",        /// The remote party is not running an endpoint
    "EndedByOffline",           /// The remote party is off line
    "EndedByTemporaryFailure",  /// The remote failed temporarily app may retry
    "EndedByQ931Cause",         /// The remote ended the call with unmapped Q.931 cause code
    "EndedByDurationLimit",     /// Call cleared due to an enforced duration limit
    "EndedByInvalidConferenceID",/// Call cleared due to invalid conference ID
    "EndedByNoDialTone",        /// Call cleared due to missing dial tone
    "EndedByNoRingBackTone",    /// Call cleared due to missing ringback tone
    "EndedByOutOfService",      /// Call cleared because the line is out of service,
    "EndedByAcceptingCallWaiting", /// Call cleared because another call is answered
    "EndedByGkAdmissionFailed", /// Call cleared because gatekeeper admission request failed.
  };
  PAssert((PINDEX)(reason & 0xff) < PARRAYSIZE(names), "Invalid reason");
  return out << names[reason & 0xff];
}

ostream & operator<<(ostream & o, OpalConnection::AnswerCallResponse s)
{
  static const char * const AnswerCallResponseNames[OpalConnection::NumAnswerCallResponses] = {
    "AnswerCallNow",
    "AnswerCallDenied",
    "AnswerCallPending",
    "AnswerCallDeferred",
    "AnswerCallAlertWithMedia",
    "AnswerCallDeferredWithMedia",
    "AnswerCallProgress",
    "AnswerCallNowAndReleaseCurrent"
  };
  if ((PINDEX)s >= PARRAYSIZE(AnswerCallResponseNames))
    o << "InvalidAnswerCallResponse<" << (unsigned)s << '>';
  else if (AnswerCallResponseNames[s] == NULL)
    o << "AnswerCallResponse<" << (unsigned)s << '>';
  else
    o << AnswerCallResponseNames[s];
  return o;
}

ostream & operator<<(ostream & o, OpalConnection::SendUserInputModes m)
{
  static const char * const SendUserInputModeNames[OpalConnection::NumSendUserInputModes] = {
    "SendUserInputAsQ931",
    "SendUserInputAsString",
    "SendUserInputAsTone",
    "SendUserInputAsRFC2833",
    "SendUserInputInBand",
    "SendUserInputAsProtocolDefault"
  };

  if ((PINDEX)m >= PARRAYSIZE(SendUserInputModeNames))
    o << "InvalidSendUserInputMode<" << (unsigned)m << '>';
  else if (SendUserInputModeNames[m] == NULL)
    o << "SendUserInputMode<" << (unsigned)m << '>';
  else
    o << SendUserInputModeNames[m];
  return o;
}

#endif


static POrdinalToString::Initialiser const CallEndReasonStringsInitialiser[] = {
  { OpalConnection::EndedByLocalUser,            "Local party cleared call" },
  { OpalConnection::EndedByNoAccept,             "Local party did not accept call" },
  { OpalConnection::EndedByAnswerDenied,         "Local party declined to answer call" },
  { OpalConnection::EndedByRemoteUser,           "Remote party cleared call" },
  { OpalConnection::EndedByRefusal,              "Remote party refused call" },
  { OpalConnection::EndedByNoAnswer,             "Remote party did not answer in required time" },
  { OpalConnection::EndedByCallerAbort,          "Remote party stopped calling" },
  { OpalConnection::EndedByTransportFail,        "Call failed due to a transport error" },
  { OpalConnection::EndedByConnectFail,          "Connection to remote failed" },
  { OpalConnection::EndedByGatekeeper,           "Gatekeeper has cleared call" },
  { OpalConnection::EndedByNoUser,               "Call failed as could not find user" },
  { OpalConnection::EndedByNoBandwidth,          "Call failed due to insufficient bandwidth" },
  { OpalConnection::EndedByCapabilityExchange,   "Call failed as could not find common media capabilities" },
  { OpalConnection::EndedByCallForwarded,        "Call was forwarded" },
  { OpalConnection::EndedBySecurityDenial,       "Call failed security check" },
  { OpalConnection::EndedByLocalBusy,            "Local party busy" },
  { OpalConnection::EndedByLocalCongestion,      "Local party congested" },
  { OpalConnection::EndedByRemoteBusy,           "Remote party busy" },
  { OpalConnection::EndedByRemoteCongestion,     "Remote switch congested" },
  { OpalConnection::EndedByUnreachable,          "Remote party could not be reached" },
  { OpalConnection::EndedByNoEndPoint,           "Remote party application is not running" },
  { OpalConnection::EndedByHostOffline,          "Remote party host is off line" },
  { OpalConnection::EndedByTemporaryFailure,     "Remote system failed temporarily" },
  { OpalConnection::EndedByQ931Cause,            "Call cleared with Q.931 cause code %u" },
  { OpalConnection::EndedByDurationLimit,        "Call cleared due to an enforced duration limit" },
  { OpalConnection::EndedByInvalidConferenceID,  "Call cleared due to invalid conference ID" },
  { OpalConnection::EndedByNoDialTone,           "Call cleared due to missing dial tone" },
  { OpalConnection::EndedByNoRingBackTone,       "Call cleared due to missing ringback tone" },
  { OpalConnection::EndedByOutOfService,         "Call cleared because the line is out of service" },
  { OpalConnection::EndedByAcceptingCallWaiting, "Call cleared because another call is answered" },
  { OpalConnection::EndedByGkAdmissionFailed,    "Call cleared because gatekeeper admission request failed." },
};

static POrdinalToString CallEndReasonStrings(PARRAYSIZE(CallEndReasonStringsInitialiser), CallEndReasonStringsInitialiser);


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

OpalConnection::OpalConnection(OpalCall & call,
                               OpalEndPoint  & ep,
                               const PString & token,
                               unsigned int options,
                               OpalConnection::StringOptions * stringOptions)
  : PSafeObject(&call)  // Share the lock flag from the call
  , ownerCall(call)
  , endpoint(ep)
  , m_phase(UninitialisedPhase)
  , callToken(token)
  , originating(PFalse)
  , productInfo(ep.GetProductInfo())
  , localPartyName(ep.GetDefaultLocalPartyName())
  , displayName(ep.GetDefaultDisplayName())
  , remotePartyName(token)
  , callEndReason(NumCallEndReasons)
  , silenceDetector(NULL)
#if OPAL_AEC
  , echoCanceler(NULL)
#endif
#if OPAL_PTLIB_DTMF
  , m_dtmfScaleMultiplier(1)
  , m_dtmfScaleDivisor(1)
#ifdef _MSC_VER
#pragma warning(disable:4355)
#endif
  , m_dtmfDetectNotifier(PCREATE_NOTIFIER(OnDetectInBandDTMF))
  , m_sendInBandDTMF(true)
  , m_emittedInBandDTMF(0)
#endif
  , m_dtmfSendNotifier(PCREATE_NOTIFIER(OnSendInBandDTMF))
#if OPAL_HAS_MIXER
  , m_recordAudioNotifier(PCREATE_NOTIFIER(OnRecordAudio))
#if OPAL_VIDEO
  , m_recordVideoNotifier(PCREATE_NOTIFIER(OnRecordVideo))
#endif
#endif
#ifdef _MSC_VER
#pragma warning(default:4355)
#endif
#if OPAL_STATISTICS
  , m_VideoUpdateRequestsSent(0)
#endif
#if OPAL_FAX
  , m_faxMediaStreamsSwitchState(e_NotSwitchingFaxMediaStreams)
#endif
#if P_LUA
  , m_luaScriptLoaded(false)
#endif
{
  PTRACE(3, "OpalCon\tCreated connection " << *this);

  PAssert(ownerCall.SafeReference(), PLogicError);

  ownerCall.connectionsActive.Append(this);

  if (stringOptions != NULL)
    m_stringOptions = *stringOptions;

  minAudioJitterDelay = endpoint.GetManager().GetMinAudioJitterDelay();
  maxAudioJitterDelay = endpoint.GetManager().GetMaxAudioJitterDelay();
  bandwidthAvailable = endpoint.GetInitialBandwidth();

#if OPAL_PTLIB_DTMF
  switch (options&DetectInBandDTMFOptionMask) {
    case DetectInBandDTMFOptionDisable :
      m_detectInBandDTMF = false;
      break;

    case DetectInBandDTMFOptionEnable :
      m_detectInBandDTMF = true;
      break;

    default :
      m_detectInBandDTMF = !endpoint.GetManager().DetectInBandDTMFDisabled();
      break;
  }
#endif

  switch (options & SendDTMFMask) {
    case SendDTMFAsString:
      sendUserInputMode = SendUserInputAsString;
      break;
    case SendDTMFAsTone:
      sendUserInputMode = SendUserInputAsTone;
      break;
    case SendDTMFAsRFC2833:
      sendUserInputMode = SendUserInputAsRFC2833;
      break;
    case SendDTMFAsDefault:
    default:
      sendUserInputMode = ep.GetSendUserInputMode();
      break;
  }

#if 0 // OPAL_HAS_IM
  m_rfc4103Context[0].SetMediaFormat(OpalT140);
  m_rfc4103Context[1].SetMediaFormat(OpalT140);
#endif

#if P_LUA
  BindToInstance(m_lua, "connection");
  m_lua.SetFunction("PTRACE", PLua::TraceFunction);
  m_lua.SetValue("token",  callToken);

  PString str = GetPrefixName();
  m_lua.SetValue("prefix", str);
  m_lua.CallLuaFunction("OnConstruct");
#endif

  m_phaseTime[UninitialisedPhase].SetCurrentTime();
}

OpalConnection::~OpalConnection()
{
  mediaStreams.RemoveAll();

  delete silenceDetector;
#if OPAL_AEC
  delete echoCanceler;
#endif
#if OPAL_T120DATA
  delete t120handler;
#endif

#if P_LUA
  m_lua.CallLuaFunction("OnDestroy");
  UnbindFromInstance(m_lua, "call");
#endif

  ownerCall.connectionsActive.Remove(this);
  ownerCall.SafeDereference();

  PTRACE(3, "OpalCon\tConnection " << *this << " destroyed.");
}


void OpalConnection::PrintOn(ostream & strm) const
{
  strm << ownerCall << '-'<< endpoint << '[' << callToken << ']';
}


bool OpalConnection::GarbageCollection()
{
  return mediaStreams.DeleteObjectsToBeRemoved();
}


PBoolean OpalConnection::OnSetUpConnection()
{
  PTRACE(3, "OpalCon\tOnSetUpConnection" << *this);
  return endpoint.OnSetUpConnection(*this);
}


bool OpalConnection::Hold(bool /*fromRemote*/, bool /*placeOnHold*/)
{
  return false;
}


PBoolean OpalConnection::IsOnHold(bool /*fromRemote*/)
{
  return false;
}


void OpalConnection::OnHold(bool fromRemote, bool onHold)
{
  PTRACE(4, "OpalCon\tOnHold " << *this);
  endpoint.OnHold(*this, fromRemote, onHold);
}


PString OpalConnection::GetCallEndReasonText(CallEndReason reason)
{
  return psprintf(CallEndReasonStrings(reason.code), reason.q931);
}


void OpalConnection::SetCallEndReasonText(CallEndReasonCodes reasonCode, const PString & newText)
{
  CallEndReasonStrings.SetAt(reasonCode, newText);
}


void OpalConnection::SetCallEndReason(CallEndReason reason)
{
  PWaitAndSignal mutex(m_phaseMutex);

  // Only set reason if not already set to something
  if (callEndReason == NumCallEndReasons) {
    PTRACE(3, "OpalCon\tCall end reason for " << *this << " set to " << reason);
    callEndReason = reason;
    ownerCall.SetCallEndReason(reason);
  }
}


void OpalConnection::ClearCall(CallEndReason reason, PSyncPoint * sync)
{
  SetCallEndReason(reason);
  ownerCall.Clear(reason, sync);
}


void OpalConnection::ClearCallSynchronous(PSyncPoint * sync, CallEndReason reason)
{
  SetCallEndReason(reason);

  PSyncPoint syncPoint;
  if (sync == NULL)
    sync = &syncPoint;

  ClearCall(reason, sync);

  PTRACE(5, "OpalCon\tSynchronous wait for " << *this);
  sync->Wait();
}


bool OpalConnection::TransferConnection(const PString & PTRACE_PARAM(remoteParty))
{
  PTRACE(2, "OpalCon\tCan not transfer connection to " << remoteParty);
  return false;
}


void OpalConnection::Release(CallEndReason reason, bool synchronous)
{
  {
    PWaitAndSignal mutex(m_phaseMutex);
    if (IsReleased()) {
      PTRACE(3, "OpalCon\tAlready released " << *this);
      return;
    }
    SetPhase(ReleasingPhase);
    SetCallEndReason(reason);
  }

  if (synchronous) {
    PTRACE(3, "OpalCon\tReleasing synchronously " << *this);
    OnReleased();
    return;
  }

  PTRACE(3, "OpalCon\tReleasing asynchronously " << *this);

  // Add a reference for the thread we are about to start
  SafeReference();
  PThread::Create(PCREATE_NOTIFIER(OnReleaseThreadMain), 0,
                  PThread::AutoDeleteThread,
                  PThread::NormalPriority,
                  "OnRelease");
}


void OpalConnection::OnReleaseThreadMain(PThread &, INT)
{
  OnReleased();

  PTRACE(4, "OpalCon\tOnRelease thread completed for " << *this);

  // Dereference on the way out of the thread
  SafeDereference();
}


void OpalConnection::OnReleased()
{
  PTRACE(4, "OpalCon\tOnReleased " << *this);

  CloseMediaStreams();

  endpoint.OnReleased(*this);

  SetPhase(ReleasedPhase);

#if PTRACING
  static const int Level = 3;
  if (PTrace::CanTrace(Level)) {
    ostream & trace = PTrace::Begin(Level, __FILE__, __LINE__);
    trace << "OpalCon\tConnection " << *this << " released\n"
             "        Initial Time: " << m_phaseTime[UninitialisedPhase] << '\n';
    for (Phases ph = SetUpPhase; ph < NumPhases; ph = (Phases)(ph+1)) {
      trace << setw(20) << ph << ": ";
      if (m_phaseTime[ph].IsValid())
        trace << (m_phaseTime[ph]-m_phaseTime[UninitialisedPhase]);
      else
        trace << "N/A";
      trace << '\n';
    }
    trace << "     Call end reason: " << callEndReason << '\n'
          << PTrace::End;
  }
#endif
}


PBoolean OpalConnection::OnIncomingConnection(unsigned options, OpalConnection::StringOptions * stringOptions)
{
  return endpoint.OnIncomingConnection(*this, options, stringOptions);
}


PString OpalConnection::GetDestinationAddress()
{
  return '*';
}


PBoolean OpalConnection::ForwardCall(const PString & /*forwardParty*/)
{
  return PFalse;
}


PSafePtr<OpalConnection> OpalConnection::GetOtherPartyConnection() const
{
  return GetCall().GetOtherPartyConnection(*this);
}


void OpalConnection::OnProceeding()
{
  endpoint.OnProceeding(*this);
}

void OpalConnection::OnAlerting()
{
  endpoint.OnAlerting(*this);
}

OpalConnection::AnswerCallResponse OpalConnection::OnAnswerCall(const PString & callerName)
{
  return endpoint.OnAnswerCall(*this, callerName);
}


void OpalConnection::AnsweringCall(AnswerCallResponse response)
{
  PTRACE(3, "OpalCon\tAnswering call: " << response);

  PSafeLockReadWrite safeLock(*this);
  // Can only answer call in UninitialisedPhase, SetUpPhase and AlertingPhase phases
  if (!safeLock.IsLocked() || GetPhase() > AlertingPhase)
    return;

  switch (response) {
    case AnswerCallDenied :
      // If response is denied, abort the call
      Release(EndedByAnswerDenied);
      break;

    case AnswerCallAlertWithMedia :
      SetAlerting(GetLocalPartyName(), PTrue);
      break;

    case AnswerCallPending :
      SetAlerting(GetLocalPartyName(), PFalse);
      break;

    case AnswerCallNow:
      PTRACE(3, "OpalCon\tApplication has answered incoming call");
      GetOtherPartyConnection()->OnConnectedInternal();
      break;

    default : // AnswerCallDeferred etc
      break;
  }
}


PBoolean OpalConnection::SetConnected()
{
  PTRACE(3, "OpalCon\tSetConnected for " << *this);

  if (GetPhase() < ConnectedPhase)
    SetPhase(ConnectedPhase);

  if (!mediaStreams.IsEmpty() && GetPhase() < EstablishedPhase) {
    SetPhase(EstablishedPhase);
    OnEstablished();
  }

  return true;
}


void OpalConnection::OnConnectedInternal()
{
  if (GetPhase() < ConnectedPhase) {
    SetPhase(ConnectedPhase);
    OnConnected();
  }

  if (!mediaStreams.IsEmpty() && GetPhase() < EstablishedPhase) {
    SetPhase(EstablishedPhase);
    OnEstablished();
  }
}


void OpalConnection::OnConnected()
{
  PTRACE(3, "OpalCon\tOnConnected for " << *this);
  endpoint.OnConnected(*this);
}


void OpalConnection::OnEstablished()
{
  PTRACE(3, "OpalCon\tOnEstablished " << *this);
  ownerCall.StartMediaStreams();
  endpoint.OnEstablished(*this);
}


bool OpalConnection::OnTransferNotify(const PStringToString & info,
                                      const OpalConnection * transferringConnection)
{
  if (transferringConnection == this) {
    PSafePtr<OpalConnection> otherConnection = GetOtherPartyConnection();
    if (otherConnection != NULL)
      otherConnection->OnTransferNotify(info, transferringConnection);
  }

  return endpoint.OnTransferNotify(*this, info);

}


void OpalConnection::AdjustMediaFormats(bool   local,
                        const OpalConnection * otherConnection,
                         OpalMediaFormatList & mediaFormats) const
{
  if (otherConnection != NULL)
    return;

  mediaFormats.Remove(m_stringOptions(OPAL_OPT_REMOVE_CODEC).Lines());

  if (local) {
    for (PINDEX i = 0; i < m_stringOptions.GetSize(); ++i) {
      PString key = m_stringOptions.GetKeyAt(i);
      PINDEX colon = key.Find(':');
      if (colon != P_MAX_INDEX) {
        PString fmtName = key.Left(colon);
        PString optName = key.Mid(colon+1);
        if (!fmtName.IsEmpty() && !optName.IsEmpty()) {
          PString optValue = m_stringOptions.GetDataAt(i);
          OpalMediaFormatList::const_iterator iterFormat;
          while ((iterFormat = mediaFormats.FindFormat(fmtName, iterFormat)) != mediaFormats.end()) {
            OpalMediaFormat & format = const_cast<OpalMediaFormat &>(*iterFormat);
            if (format.SetOptionValue(optName, optValue)) {
              PTRACE(4, "OpalCon\tSet media format " << format
                     << " option " << optName << " to \"" << optValue << '"');
            }
            else {
              PTRACE(2, "OpalCon\tFailed to set media format " << format
                     << " option " << optName << " to \"" << optValue << '"');
            }
          }
        }
      }
    }
  }

  endpoint.AdjustMediaFormats(local, *this, mediaFormats);
}


unsigned OpalConnection::GetNextSessionID(const OpalMediaType & /*mediaType*/, bool /*isSource*/)
{
  return 0;
}


void OpalConnection::AutoStartMediaStreams(bool force)
{
  OpalMediaTypeFactory::KeyList_T mediaTypes = OpalMediaType::GetList();
  for (OpalMediaTypeFactory::KeyList_T::iterator iter = mediaTypes.begin(); iter != mediaTypes.end(); ++iter) {
    OpalMediaType mediaType = *iter;
    if ((GetAutoStart(mediaType)&OpalMediaType::Transmit) != 0 && (force || GetMediaStream(mediaType, true) == NULL))
      ownerCall.OpenSourceMediaStreams(*this, mediaType, mediaType.GetDefinition()->GetDefaultSessionId());
  }
  StartMediaStreams();
}


#if OPAL_FAX
bool OpalConnection::SwitchFaxMediaStreams(bool toT38)
{
  if (m_faxMediaStreamsSwitchState != e_NotSwitchingFaxMediaStreams) {
    PTRACE(2, "OpalCon\tNested call to SwitchFaxMediaStreams on " << *this);
    return false;
  }

  PTRACE(3, "OpalCon\tSwitchFaxMediaStreams to " << (toT38 ? "T.38" : "audio") << " on " << *this);
  OpalMediaFormat format = toT38 ? OpalT38 : OpalG711uLaw;
  if (!ownerCall.OpenSourceMediaStreams(*this, format.GetMediaType(), 1, format))
    return false;

  m_faxMediaStreamsSwitchState = toT38 ? e_SwitchingToFaxMediaStreams : e_SwitchingFromFaxMediaStreams;
  return true;
}


void OpalConnection::OnSwitchedFaxMediaStreams(bool toT38, bool success)
{
  if (m_faxMediaStreamsSwitchState != e_NotSwitchingFaxMediaStreams) {
    PTRACE(3, "OpalCon\tSwitch of media streams to "
           << (toT38 ? "T.38" : "audio") << ' '
           << (success ? "succeeded" : "failed")
           << " on " << *this);

    m_faxMediaStreamsSwitchState = e_NotSwitchingFaxMediaStreams;

    PSafePtr<OpalConnection> other = GetOtherPartyConnection();
    if (other != NULL)
      other->OnSwitchedFaxMediaStreams(toT38, success);
  }
}


bool OpalConnection::OnSwitchingFaxMediaStreams(bool toT38)
{
  PTRACE(3, "OpalCon\tRemote switch of media streams to " << (toT38 ? "T.38" : "audio") << " on " << *this);
  return !toT38;
}
#endif


OpalMediaStreamPtr OpalConnection::OpenMediaStream(const OpalMediaFormat & mediaFormat, unsigned sessionID, bool isSource)
{
  PSafeLockReadWrite safeLock(*this);
  if (!safeLock.IsLocked())
    return NULL;

  // See if already opened
  OpalMediaStreamPtr stream = GetMediaStream(sessionID, isSource);
  if (stream != NULL && stream->IsOpen()) {
    if (stream->GetMediaFormat() == mediaFormat) {
      PTRACE(3, "OpalCon\tOpenMediaStream (already opened) for session " << sessionID << " on " << *this);
      return stream;
    }
    // Changing the media format, needs to close and re-open the stream
    stream->Close();
    stream.SetNULL();
  }

  if (stream == NULL) {
    stream = CreateMediaStream(mediaFormat, sessionID, isSource);
    if (stream == NULL) {
      PTRACE(1, "OpalCon\tCreateMediaStream returned NULL for session " << sessionID << " on " << *this);
      return NULL;
    }
    mediaStreams.Append(stream);
  }

  if (stream->Open()) {
    if (OnOpenMediaStream(*stream)) {
      PTRACE(3, "OpalCon\tOpened " << (isSource ? "source" : "sink") << " stream " << stream->GetID() << " with format " << mediaFormat);
      return stream;
    }
    PTRACE(2, "OpalCon\tOnOpenMediaStream failed for " << mediaFormat << ", closing " << *stream);
    stream->Close();
  }
  else {
    PTRACE(2, "OpalCon\tSource media stream open failed for " << *stream << " (" << mediaFormat << ')');
  }

  mediaStreams.Remove(stream);

  return NULL;
}


bool OpalConnection::CloseMediaStream(unsigned sessionId, bool source)
{
  OpalMediaStreamPtr stream = GetMediaStream(sessionId, source);
  return stream != NULL && stream->IsOpen() && CloseMediaStream(*stream);
}


bool OpalConnection::CloseMediaStream(OpalMediaStream & stream)
{
  return stream.Close();
}


PBoolean OpalConnection::RemoveMediaStream(OpalMediaStream & stream)
{
  stream.Close();
  PTRACE(3, "OpalCon\tRemoved media stream " << stream);
  return mediaStreams.Remove(&stream);
}


void OpalConnection::StartMediaStreams()
{
  for (OpalMediaStreamPtr mediaStream = mediaStreams; mediaStream != NULL; ++mediaStream)
    mediaStream->Start();

  PTRACE(3, "OpalCon\tMedia stream threads started for " << *this);
}


void OpalConnection::CloseMediaStreams()
{
  // Do this double loop as while closing streams, the instance may disappear from the
  // mediaStreams list, prematurely stopping the for loop.
  bool someOpen = true;
  while (someOpen) {
    someOpen = false;
    for (OpalMediaStreamPtr mediaStream(mediaStreams, PSafeReference); mediaStream != NULL; ++mediaStream) {
      if (mediaStream->IsOpen()) {
        someOpen = true;
        CloseMediaStream(*mediaStream);
      }
    }
  }

  PTRACE(3, "OpalCon\tMedia streams closed.");
}


void OpalConnection::PauseMediaStreams(bool paused)
{
  for (OpalMediaStreamPtr mediaStream = mediaStreams; mediaStream != NULL; ++mediaStream)
    mediaStream->SetPaused(paused);
}


void OpalConnection::OnPauseMediaStream(OpalMediaStream & /*strm*/, bool /*paused*/)
{
}


#if OPAL_VIDEO
OpalMediaStream * OpalConnection::CreateMediaStream(const OpalMediaFormat & mediaFormat,
                                                    unsigned sessionID,
                                                    PBoolean isSource)
{
  if (mediaFormat.GetMediaType() == OpalMediaType::Video()) {
    if (isSource) {
      PVideoInputDevice * videoDevice;
      PBoolean autoDeleteGrabber;
      if (CreateVideoInputDevice(mediaFormat, videoDevice, autoDeleteGrabber)) {
        PTRACE(4, "OpalCon\tCreated capture device \"" << videoDevice->GetDeviceName() << '"');

        PVideoOutputDevice * previewDevice;
        PBoolean autoDeletePreview;
        if (CreateVideoOutputDevice(mediaFormat, PTrue, previewDevice, autoDeletePreview))
          PTRACE(4, "OpalCon\tCreated preview device \"" << previewDevice->GetDeviceName() << '"');
        else
          previewDevice = NULL;

        return new OpalVideoMediaStream(*this, mediaFormat, sessionID, videoDevice, previewDevice, autoDeleteGrabber, autoDeletePreview);
      }
    }
    else {
      PVideoOutputDevice * videoDevice;
      PBoolean autoDelete;
      if (CreateVideoOutputDevice(mediaFormat, PFalse, videoDevice, autoDelete)) {
        PTRACE(4, "OpalCon\tCreated display device \"" << videoDevice->GetDeviceName() << '"');
        return new OpalVideoMediaStream(*this, mediaFormat, sessionID, NULL, videoDevice, false, autoDelete);
      }
    }
  }

  return NULL;
}
#else
OpalMediaStream * OpalConnection::CreateMediaStream(const OpalMediaFormat &, unsigned, PBoolean)
{
  return NULL;
}
#endif


PBoolean OpalConnection::OnOpenMediaStream(OpalMediaStream & stream)
{
  if (!endpoint.OnOpenMediaStream(*this, stream))
    return PFalse;

  if (!LockReadWrite())
    return PFalse;

  if (GetPhase() == ConnectedPhase) {
    SetPhase(EstablishedPhase);
    OnEstablished();
  }

  UnlockReadWrite();

  return PTrue;
}


void OpalConnection::OnClosedMediaStream(const OpalMediaStream & stream)
{
  OpalMediaPatch * patch = stream.GetPatch();
  if (patch != NULL) {
#if OPAL_HAS_MIXER
    OnStopRecording(patch);
#endif

    if (silenceDetector != NULL && patch->RemoveFilter(silenceDetector->GetReceiveHandler(), m_filterMediaFormat)) {
      PTRACE(4, "OpalCon\tRemoved silence detect filter on connection " << *this << ", patch " << patch);
    }

#if OPAL_AEC
    if (echoCanceler != NULL && patch->RemoveFilter(stream.IsSource() ? echoCanceler->GetReceiveHandler()
                                                  : echoCanceler->GetSendHandler(), m_filterMediaFormat)) {
      PTRACE(4, "OpalCon\tRemoved echo canceler filter on connection " << *this << ", patch " << patch);
    }
#endif

#if OPAL_PTLIB_DTMF
    if (patch->RemoveFilter(m_dtmfDetectNotifier, OpalPCM16)) {
      PTRACE(4, "OpalCon\tRemoved detect DTMF filter on connection " << *this << ", patch " << patch);
    }
    if (!m_dtmfSendFormat.IsEmpty() && patch->RemoveFilter(m_dtmfSendNotifier, m_dtmfSendFormat)) {
      PTRACE(4, "OpalCon\tRemoved DTMF send filter on connection " << *this << ", patch " << patch);
    }
#endif
  }

  endpoint.OnClosedMediaStream(stream);
}

#if OPAL_HAS_MIXER

static PString MakeRecordingKey(const OpalMediaPatch & patch)
{
  return psprintf("%08x", &patch);
}


void OpalConnection::OnStartRecording(OpalMediaPatch * patch)
{
  if (patch == NULL)
    return;

  if (!ownerCall.OnStartRecording(MakeRecordingKey(*patch), patch->GetSource().GetMediaFormat())) {
    PTRACE(4, "OpalCon\tNo record filter added on connection " << *this << ", patch " << *patch);
    return;
  }

  patch->AddFilter(m_recordAudioNotifier, OpalPCM16);
#if OPAL_VIDEO
  patch->AddFilter(m_recordVideoNotifier, OPAL_YUV420P);
#endif

  PTRACE(4, "OpalCon\tAdded record filter on connection " << *this << ", patch " << *patch);
}


void OpalConnection::OnStopRecording(OpalMediaPatch * patch)
{
  if (patch == NULL)
    return;

  ownerCall.OnStopRecording(MakeRecordingKey(*patch));

  patch->RemoveFilter(m_recordAudioNotifier, OpalPCM16);
#if OPAL_VIDEO
  patch->RemoveFilter(m_recordVideoNotifier, OPAL_YUV420P);
#endif

  PTRACE(4, "OpalCon\tRemoved record filter on " << *patch);
}

#endif

void OpalConnection::OnPatchMediaStream(PBoolean isSource, OpalMediaPatch & patch)
{
  OpalMediaFormat mediaFormat = isSource ? patch.GetSource().GetMediaFormat() : patch.GetSink()->GetMediaFormat();

  if (mediaFormat.GetMediaType() == OpalMediaType::Audio()) {
    if (!mediaFormat.IsTransportable()) {
      m_filterMediaFormat = mediaFormat;

      if (isSource && silenceDetector != NULL) {
        silenceDetector->SetParameters(endpoint.GetManager().GetSilenceDetectParams(), mediaFormat.GetClockRate());
        patch.AddFilter(silenceDetector->GetReceiveHandler(), mediaFormat);
        PTRACE(4, "OpalCon\tAdded silence detect filter on connection " << *this << ", patch " << patch);
      }

#if OPAL_AEC
      if (echoCanceler) {
        echoCanceler->SetParameters(endpoint.GetManager().GetEchoCancelParams());
        echoCanceler->SetClockRate(mediaFormat.GetClockRate());
        patch.AddFilter(isSource ? echoCanceler->GetReceiveHandler()
                                 : echoCanceler->GetSendHandler(), mediaFormat);
        PTRACE(4, "OpalCon\tAdded echo canceler filter on connection " << *this << ", patch " << patch);
      }
#endif
    }

#if OPAL_PTLIB_DTMF
    if (m_detectInBandDTMF && isSource) {
      patch.AddFilter(m_dtmfDetectNotifier, OpalPCM16);
      PTRACE(4, "OpalCon\tAdded detect DTMF filter on connection " << *this << ", patch " << patch);
    }

    if (m_sendInBandDTMF && !isSource) {
      if (mediaFormat == OpalG711_ULAW_64K || mediaFormat == OpalG711_ALAW_64K)
        m_dtmfSendFormat = mediaFormat;
      else
        m_dtmfSendFormat = OpalPCM16;
      patch.AddFilter(m_dtmfSendNotifier, mediaFormat);
      PTRACE(4, "OpalCon\tAdded send DTMF filter on connection " << *this << ", patch " << patch);
    }
#endif
  }

#if OPAL_HAS_MIXER
  if (!m_recordingFilename.IsEmpty())
    ownerCall.StartRecording(m_recordingFilename);
  else if (ownerCall.IsRecording())
    OnStartRecording(&patch);
#endif

  PTRACE(3, "OpalCon\t" << (isSource ? "Source" : "Sink") << " stream of connection " << *this << " uses patch " << patch);
}


#if OPAL_HAS_MIXER
void OpalConnection::EnableRecording()
{
  OpalMediaStreamPtr stream = GetMediaStream(OpalMediaType::Audio(), true);
  if (stream != NULL)
    OnStartRecording(stream->GetPatch());

  stream = GetMediaStream(OpalMediaType::Video(), true);
  if (stream != NULL)
    OnStartRecording(stream->GetPatch());
}


void OpalConnection::DisableRecording()
{
  OpalMediaStreamPtr stream = GetMediaStream(OpalMediaType::Audio(), true);
  if (stream != NULL)
    OnStopRecording(stream->GetPatch());

  stream = GetMediaStream(OpalMediaType::Video(), true);
  if (stream != NULL)
    OnStopRecording(stream->GetPatch());
}


void OpalConnection::OnRecordAudio(RTP_DataFrame & frame, INT param)
{
  const OpalMediaPatch * patch = (const OpalMediaPatch *)param;
  ownerCall.OnRecordAudio(MakeRecordingKey(*patch), frame);
}


#if OPAL_VIDEO

void OpalConnection::OnRecordVideo(RTP_DataFrame & frame, INT param)
{
  const OpalMediaPatch * patch = (const OpalMediaPatch *)param;
  ownerCall.OnRecordVideo(MakeRecordingKey(*patch), frame);
}

#endif

#endif


void OpalConnection::AttachRFC2833HandlerToPatch(PBoolean /*isSource*/, OpalMediaPatch & /*patch*/)
{
}


OpalMediaStreamPtr OpalConnection::GetMediaStream(const PString & streamID, bool source) const
{
  for (PSafePtr<OpalMediaStream> mediaStream(mediaStreams, PSafeReference); mediaStream != NULL; ++mediaStream) {
    if ((streamID.IsEmpty() || mediaStream->GetID() == streamID) && mediaStream->IsSource() == source)
      return mediaStream;
  }

  return NULL;
}


OpalMediaStreamPtr OpalConnection::GetMediaStream(unsigned sessionId, bool source) const
{
  for (OpalMediaStreamPtr mediaStream(mediaStreams, PSafeReference); mediaStream != NULL; ++mediaStream) {
    if (mediaStream->GetSessionID() == sessionId && mediaStream->IsSource() == source)
      return mediaStream;
  }

  return NULL;
}


OpalMediaStreamPtr OpalConnection::GetMediaStream(const OpalMediaType & mediaType,
                                                  bool source,
                                                  OpalMediaStreamPtr mediaStream) const
{
  if (mediaStream == NULL)
    mediaStream = OpalMediaStreamPtr(mediaStreams, PSafeReference);
  else
    ++mediaStream;

  while (mediaStream != NULL) {
    if ((mediaType.empty() || mediaStream->GetMediaFormat().GetMediaType() == mediaType) && mediaStream->IsSource() == source)
      return mediaStream;
    ++mediaStream;
  }

  return NULL;
}


PBoolean OpalConnection::IsMediaBypassPossible(unsigned /*sessionID*/) const
{
  PTRACE(4, "OpalCon\tIsMediaBypassPossible: default returns false");
  return false;
}


#if OPAL_VIDEO

PBoolean OpalConnection::CreateVideoInputDevice(const OpalMediaFormat & mediaFormat,
                                            PVideoInputDevice * & device,
                                            PBoolean & autoDelete)
{
  return endpoint.CreateVideoInputDevice(*this, mediaFormat, device, autoDelete);
}


PBoolean OpalConnection::CreateVideoOutputDevice(const OpalMediaFormat & mediaFormat,
                                             PBoolean preview,
                                             PVideoOutputDevice * & device,
                                             PBoolean & autoDelete)
{
  return endpoint.CreateVideoOutputDevice(*this, mediaFormat, preview, device, autoDelete);
}


bool OpalConnection::SendVideoUpdatePicture(unsigned sessionID, bool force) const
{
  if (IsReleased())
    return false;

  OpalMediaStreamPtr stream = sessionID != 0 ? GetMediaStream(sessionID, false)
                                             : GetMediaStream(OpalMediaType::Video(), false);
  if (stream == NULL) {
    PTRACE(3, "OpalCon\tNo video stream do video update picture in connection " << *this);
    return false;
  }

  PTRACE(3, "OpalCon\tVideo update picture (I-Frame) requested in video stream " << *stream << " on " << *this);
  if (force)
    stream->ExecuteCommand(OpalVideoUpdatePicture());
  else
    stream->ExecuteCommand(OpalVideoPictureLoss());

  return true;
}

#endif // OPAL_VIDEO


PBoolean OpalConnection::SetAudioVolume(PBoolean /*source*/, unsigned /*percentage*/)
{
  return PFalse;
}


PBoolean OpalConnection::GetAudioVolume(PBoolean /*source*/, unsigned & /*percentage*/)
{
  return PFalse;
}


bool OpalConnection::SetAudioMute(bool /*source*/, bool /*mute*/)
{
  return false;
}


bool OpalConnection::GetAudioMute(bool /*source*/, bool & /*mute*/)
{
  return false;
}


unsigned OpalConnection::GetAudioSignalLevel(PBoolean /*source*/)
{
    return UINT_MAX;
}

PBoolean OpalConnection::SetBandwidthAvailable(unsigned newBandwidth, PBoolean force)
{
  PTRACE(3, "OpalCon\tSetting bandwidth to " << newBandwidth << "00b/s on connection " << *this);

  unsigned used = GetBandwidthUsed();
  if (used > newBandwidth) {
    if (!force)
      return PFalse;

#if 0
    // Go through media channels and close down some.
    PINDEX chanIdx = GetmediaStreams->GetSize();
    while (used > newBandwidth && chanIdx-- > 0) {
      OpalChannel * channel = logicalChannels->GetChannelAt(chanIdx);
      if (channel != NULL) {
        used -= channel->GetBandwidthUsed();
        const H323ChannelNumber & number = channel->GetNumber();
        CloseLogicalChannel(number, number.IsFromRemote());
      }
    }
#endif
  }

  bandwidthAvailable = newBandwidth - used;
  return PTrue;
}


unsigned OpalConnection::GetBandwidthUsed() const
{
  unsigned used = 0;

#if 0
  for (PINDEX i = 0; i < logicalChannels->GetSize(); i++) {
    OpalChannel * channel = logicalChannels->GetChannelAt(i);
    if (channel != NULL)
      used += channel->GetBandwidthUsed();
  }
#endif

  PTRACE(3, "OpalCon\tBandwidth used is "
         << used << "00b/s for " << *this);

  return used;
}


PBoolean OpalConnection::SetBandwidthUsed(unsigned releasedBandwidth,
                                      unsigned requiredBandwidth)
{
  PTRACE_IF(3, releasedBandwidth > 0, "OpalCon\tBandwidth release of "
            << releasedBandwidth/10 << '.' << releasedBandwidth%10 << "kb/s");

  bandwidthAvailable += releasedBandwidth;

  PTRACE_IF(3, requiredBandwidth > 0, "OpalCon\tBandwidth request of "
            << requiredBandwidth/10 << '.' << requiredBandwidth%10
            << "kb/s, available: "
            << bandwidthAvailable/10 << '.' << bandwidthAvailable%10
            << "kb/s");

  if (requiredBandwidth > bandwidthAvailable) {
    PTRACE(2, "OpalCon\tAvailable bandwidth exceeded on " << *this);
    return PFalse;
  }

  bandwidthAvailable -= requiredBandwidth;

  return PTrue;
}

void OpalConnection::SetSendUserInputMode(SendUserInputModes mode)
{
  PTRACE(3, "OPAL\tSetting default User Input send mode to " << mode);
  sendUserInputMode = mode;
}

PBoolean OpalConnection::SendUserInputString(const PString & value)
{
  for (const char * c = value; *c != '\0'; c++) {
    if (!SendUserInputTone(*c, 0))
      return PFalse;
  }
  return PTrue;
}


#if OPAL_PTLIB_DTMF
PBoolean OpalConnection::SendUserInputTone(char tone, unsigned duration)
{
  if (m_dtmfSendFormat.IsEmpty())
    return false;

  if (duration <= 0)
    duration = PDTMFEncoder::DefaultToneLen;

  PTRACE(3, "OPAL\tSending in-band DTMF tone '" << tone << "', duration=" << duration);

  PDTMFEncoder dtmfSamples;
  dtmfSamples.AddTone(tone, duration);
  PINDEX size = dtmfSamples.GetSize();

  m_inBandMutex.Wait();

  switch (m_dtmfSendFormat.GetPayloadType()) {
    case RTP_DataFrame::PCMU :
      if (m_inBandDTMF.SetSize(size)) {
        for (PINDEX i = 0; i < size; ++i)
          m_inBandDTMF[i] = (BYTE)Opal_PCM_G711_uLaw::ConvertSample(dtmfSamples[i]);
      }
      break;

    case RTP_DataFrame::PCMA :
      if (m_inBandDTMF.SetSize(size)) {
        for (PINDEX i = 0; i < size; ++i)
          m_inBandDTMF[i] = (BYTE)Opal_PCM_G711_ALaw::ConvertSample(dtmfSamples[i]);
      }
      break;

    default :
      size *= sizeof(short);
      if (m_inBandDTMF.SetSize(size))
        memcpy(m_inBandDTMF.GetPointer(), dtmfSamples, size);
  }

  m_inBandMutex.Signal();

  return true;
}
#else
PBoolean OpalConnection::SendUserInputTone(char /*tone*/, unsigned /*duration*/)
{
  return false;
}
#endif


void OpalConnection::OnUserInputString(const PString & value)
{
  endpoint.OnUserInputString(*this, value);
}


void OpalConnection::OnUserInputTone(char tone, unsigned duration)
{
  endpoint.OnUserInputTone(*this, tone, duration);
}


PString OpalConnection::GetUserInput(unsigned timeout)
{
  PString reply;
  if (userInputAvailable.Wait(PTimeInterval(0, timeout)) && !IsReleased() && LockReadWrite()) {
    reply = userInputString;
    userInputString = PString();
    UnlockReadWrite();
  }
  return reply;
}


void OpalConnection::SetUserInput(const PString & input)
{
  if (LockReadWrite()) {
    userInputString += input;
    userInputAvailable.Signal();
    UnlockReadWrite();
  }
}


PString OpalConnection::ReadUserInput(const char * terminators,
                                      unsigned lastDigitTimeout,
                                      unsigned firstDigitTimeout)
{
  return endpoint.ReadUserInput(*this, terminators, lastDigitTimeout, firstDigitTimeout);
}


PBoolean OpalConnection::PromptUserInput(PBoolean /*play*/)
{
  return PTrue;
}


#if OPAL_PTLIB_DTMF
void OpalConnection::OnDetectInBandDTMF(RTP_DataFrame & frame, INT)
{
  // This function is set up as an 'audio filter'.
  // This allows us to access the 16 bit PCM audio (at 8Khz sample rate)
  // before the audio is passed on to the sound card (or other output device)

  // Pass the 16 bit PCM audio through the DTMF decoder
  PString tones = m_dtmfDecoder.Decode((const short *)frame.GetPayloadPtr(),
                                       frame.GetPayloadSize()/sizeof(short),
                                       m_dtmfScaleMultiplier,
                                       m_dtmfScaleDivisor);
  if (!tones.IsEmpty()) {
    PTRACE(3, "OPAL\tDTMF detected: \"" << tones << '"');
    for (PINDEX i = 0; i < tones.GetLength(); i++)
      OnUserInputTone(tones[i], PDTMFDecoder::DetectTime);
  }
}

void OpalConnection::OnSendInBandDTMF(RTP_DataFrame & frame, INT)
{
  if (m_inBandDTMF.IsEmpty())
    return;

  // Can't do the usual LockReadWrite() as deadlocks
  m_inBandMutex.Wait();

  PINDEX bytes = m_inBandDTMF.GetSize() - m_emittedInBandDTMF;
  if (bytes > frame.GetPayloadSize())
    bytes = frame.GetPayloadSize();
  memcpy(frame.GetPayloadPtr(), &m_inBandDTMF[m_emittedInBandDTMF], bytes);

  m_emittedInBandDTMF += bytes;

  if (m_emittedInBandDTMF >= m_inBandDTMF.GetSize()) {
    PTRACE(4, "OPAL\tSent in-band DTMF tone, " << m_inBandDTMF.GetSize() << " bytes");
    m_inBandDTMF.SetSize(0);
    m_emittedInBandDTMF = 0;
  }

  m_inBandMutex.Signal();
}
#endif


PString OpalConnection::GetPrefixName() const
{
  return endpoint.GetPrefixName();
}


void OpalConnection::SetLocalPartyName(const PString & name)
{
  localPartyName = name;
}


PString OpalConnection::GetLocalPartyURL() const
{
  return GetPrefixName() + ':' + PURL::TranslateString(GetLocalPartyName(), PURL::LoginTranslation);
}


bool OpalConnection::IsPresentationBlocked() const
{
  return m_stringOptions.GetBoolean(OPAL_OPT_PRESENTATION_BLOCK);
}


static PString MakeURL(const PString & prefix, const PString & partyName)
{
  if (partyName.IsEmpty())
    return PString::Empty();

  PINDEX colon = partyName.Find(':');
  if (colon != P_MAX_INDEX && partyName.FindSpan("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") == colon)
    return partyName;

  PStringStream url;
  url << prefix << ':' << partyName;
  return url;
}


PString OpalConnection::GetRemotePartyURL() const
{
  if (!remotePartyURL.IsEmpty())
    return remotePartyURL;

  return MakeURL(GetPrefixName(), GetRemotePartyAddress());
}


PString OpalConnection::GetCalledPartyURL()
{
  return MakeURL(GetPrefixName(), GetDestinationAddress());
}


void OpalConnection::CopyPartyNames(const OpalConnection & other)
{
  remotePartyName     = other.remotePartyName;
  remotePartyNumber   = other.remotePartyNumber;
  remotePartyAddress  = other.remotePartyAddress;
  remotePartyURL      = other.remotePartyURL;
  m_calledPartyName   = other.m_calledPartyName;
  m_calledPartyNumber = other.m_calledPartyNumber;
  remoteProductInfo   = other.remoteProductInfo;
}


PString OpalConnection::GetAlertingType() const
{
  return PString::Empty();
}


bool OpalConnection::SetAlertingType(const PString & /*info*/)
{
  return false;
}


PString OpalConnection::GetCallInfo() const
{
  return PString::Empty();
}


void OpalConnection::SetAudioJitterDelay(unsigned minDelay, unsigned maxDelay)
{
  maxDelay = PMAX(10, PMIN(maxDelay, 999));
  minDelay = PMAX(10, PMIN(minDelay, 999));

  if (maxDelay < minDelay)
    maxDelay = minDelay;

  minAudioJitterDelay = minDelay;
  maxAudioJitterDelay = maxDelay;
}


PString OpalConnection::GetIdentifier() const
{
  return GetToken();
}


PINDEX OpalConnection::GetMaxRtpPayloadSize() const
{
  return endpoint.GetManager().GetMaxRtpPayloadSize();
}


void OpalConnection::SetPhase(Phases phaseToSet)
{
  PTRACE(3, "OpalCon\tSetPhase from " << m_phase << " to " << phaseToSet << " for " << *this);

  PWaitAndSignal mutex(m_phaseMutex);

  // With next few lines we will prevent phase to ever go down when it
  // reaches ReleasingPhase - end result - once you call Release you never
  // go back.
  if (m_phase < ReleasingPhase || (m_phase == ReleasingPhase && phaseToSet == ReleasedPhase)) {
    m_phase = phaseToSet;
    if (!m_phaseTime[m_phase].IsValid())
      m_phaseTime[m_phase].SetCurrentTime();
  }
}


void OpalConnection::SetStringOptions(const StringOptions & options, bool overwrite)
{
  if (overwrite)
    m_stringOptions = options;
  else {
    for (PINDEX i = 0; i < options.GetSize(); ++i)
      m_stringOptions.SetAt(options.GetKeyAt(i), options.GetDataAt(i));
  }

  OnApplyStringOptions();
}

void OpalConnection::OnApplyStringOptions()
{
  endpoint.GetManager().OnApplyStringOptions(*this, m_stringOptions);

  PTRACE_IF(4, !m_stringOptions.IsEmpty(), "OpalCon\tApplying string options:\n" << m_stringOptions);

  if (LockReadWrite()) {
    PCaselessString str;

    str = m_stringOptions(IsOriginating() ? OPAL_OPT_CALLING_PARTY_NAME : OPAL_OPT_CALLED_PARTY_NAME);
    if (!str.IsEmpty())
      SetLocalPartyName(str);

    // Allow for explicitly haveing empty string for display name
    str = IsOriginating() ? OPAL_OPT_CALLING_DISPLAY_NAME : OPAL_OPT_CALLED_DISPLAY_NAME;
    if (m_stringOptions.Contains(str))
      SetDisplayName(m_stringOptions[str]);

    str = m_stringOptions(OPAL_OPT_USER_INPUT_MODE);
    if (str == "RFC2833")
      SetSendUserInputMode(SendUserInputAsRFC2833);
    else if (str == "String")
      SetSendUserInputMode(SendUserInputAsString);
    else if (str == "Tone")
      SetSendUserInputMode(SendUserInputAsTone);
    else if (str == "Q.931")
      SetSendUserInputMode(SendUserInputAsQ931);
    else if (str == "InBand") {
      SetSendUserInputMode(SendUserInputInBand);
      m_sendInBandDTMF = true;
    }

#if OPAL_PTLIB_DTMF
    m_sendInBandDTMF   = m_stringOptions.GetBoolean(OPAL_OPT_ENABLE_INBAND_DTMF, m_sendInBandDTMF);
    m_detectInBandDTMF = m_stringOptions.GetBoolean(OPAL_OPT_DETECT_INBAND_DTMF, m_detectInBandDTMF);
    m_sendInBandDTMF   = m_stringOptions.GetBoolean(OPAL_OPT_SEND_INBAND_DTMF,   m_sendInBandDTMF);

    m_dtmfScaleMultiplier = m_stringOptions.GetInteger(OPAL_OPT_DTMF_MULT, m_dtmfScaleMultiplier);
    m_dtmfScaleDivisor    = m_stringOptions.GetInteger(OPAL_OPT_DTMF_DIV,  m_dtmfScaleDivisor);
#endif

    m_autoStartInfo.Initialise(m_stringOptions);

    if (m_stringOptions.GetBoolean(OPAL_OPT_DISABLE_JITTER))
      maxAudioJitterDelay = minAudioJitterDelay = 0;
    else {
      maxAudioJitterDelay = m_stringOptions.GetInteger(OPAL_OPT_MAX_JITTER, maxAudioJitterDelay);
      minAudioJitterDelay = m_stringOptions.GetInteger(OPAL_OPT_MIN_JITTER, minAudioJitterDelay);
    }

#if OPAL_HAS_MIXER
    if (m_stringOptions.Contains(OPAL_OPT_RECORD_AUDIO))
      m_recordingFilename = m_stringOptions(OPAL_OPT_RECORD_AUDIO);
#endif

    str = m_stringOptions(OPAL_OPT_ALERTING_TYPE);
    if (!str.IsEmpty())
      SetAlertingType(str);

#if P_LUA
    if (!m_luaScriptLoaded) {
      str = m_stringOptions("script");
      bool ok = true;
      if (!str.IsEmpty())
        ok = m_lua.LoadString(str);
      else {
        str = m_stringOptions("scriptfile");
        if (!str.IsEmpty())
          m_lua.LoadFile(str);
      }
    }
    m_lua.CallLuaFunction("OnSetOptions");
#endif

    UnlockReadWrite();
  }
}


OpalMediaFormatList OpalConnection::GetMediaFormats() const
{
  return endpoint.GetMediaFormats();
}


OpalMediaFormatList OpalConnection::GetLocalMediaFormats()
{
  if (m_localMediaFormats.IsEmpty()) {
    m_localMediaFormats = ownerCall.GetMediaFormats(*this);
    PTRACE(4, "SIP\tLocal media formats set:\n    " << setfill(',') << m_localMediaFormats << setfill(' '));
  }
  return m_localMediaFormats;
}


void OpalConnection::OnStartMediaPatch(OpalMediaPatch & patch)
{
#if P_LUA
  m_lua.CallLuaFunction("OnStartMediaPatch");
#endif
  GetEndPoint().GetManager().OnStartMediaPatch(*this, patch);
}


void OpalConnection::OnStopMediaPatch(OpalMediaPatch & patch)
{
#if P_LUA
  m_lua.CallLuaFunction("OnStopMediaPatch");
#endif
  GetEndPoint().GetManager().OnStopMediaPatch(*this, patch);
}


bool OpalConnection::OnMediaCommand(OpalMediaStream & stream, const OpalMediaCommand & command)
{
  PTRACE(3, "OpalCon\tOnMediaCommand \"" << command << "\" on " << stream << " for " << *this);
  if (&stream.GetConnection() != this)
    return false;

  PSafePtr<OpalConnection> other = GetOtherPartyConnection();
  return other != NULL && other->OnMediaCommand(stream, command);
}


OpalMediaType::AutoStartMode OpalConnection::GetAutoStart(const OpalMediaType & mediaType) const
{
  return m_autoStartInfo.GetAutoStart(mediaType);
}


OpalConnection::AutoStartMap::AutoStartMap()
{
  m_initialised = false;
}


void OpalConnection::AutoStartMap::Initialise(const OpalConnection::StringOptions & stringOptions)
{
  PWaitAndSignal m(m_mutex);

  // make function idempotent
  if (m_initialised)
    return;

  m_initialised = true;

  // get autostart option as lines
  PStringArray lines = stringOptions(OPAL_OPT_AUTO_START).Lines();
  for (PINDEX i = 0; i < lines.GetSize(); ++i) {
    PString line = lines[i];
    PINDEX colon = line.Find(':');
    OpalMediaType mediaType = line.Left(colon);

    // see if media type is known, and if it is, enable it
    OpalMediaTypeDefinition * def = mediaType.GetDefinition();
    if (def != NULL) {
      if (colon == P_MAX_INDEX)
        SetAutoStart(mediaType, OpalMediaType::ReceiveTransmit);
      else {
        PStringArray tokens = line.Mid(colon+1).Tokenise(";", FALSE);
        PINDEX j;
        for (j = 0; j < tokens.GetSize(); ++j) {
          if ((tokens[i] *= "no") || (tokens[i] *= "false") || (tokens[i] *= "0"))
            SetAutoStart(mediaType, OpalMediaType::DontOffer);
          else if ((tokens[i] *= "yes") || (tokens[i] *= "true") || (tokens[i] *= "1") || (tokens[i] *= "sendrecv"))
            SetAutoStart(mediaType, OpalMediaType::ReceiveTransmit);
          else if (tokens[i] *= "recvonly")
            SetAutoStart(mediaType, OpalMediaType::Receive);
          else if (tokens[i] *= "sendonly")
            SetAutoStart(mediaType, OpalMediaType::Transmit);
          else if ((tokens[i] *= "offer") || (tokens[i] *= "inactive"))
            SetAutoStart(mediaType, OpalMediaType::OfferInactive);
          else if (tokens[i] *= "exclusive") {
            OpalMediaTypeFactory::KeyList_T types = OpalMediaType::GetList();
            for (OpalMediaTypeFactory::KeyList_T::iterator r = types.begin(); r != types.end(); ++r)
              SetAutoStart(*r, *r == mediaType ? OpalMediaType::ReceiveTransmit : OpalMediaType::DontOffer);
          }
        }
      }
    }
  }
}


void OpalConnection::AutoStartMap::SetAutoStart(const OpalMediaType & mediaType, OpalMediaType::AutoStartMode autoStart)
{
  PWaitAndSignal m(m_mutex);
  m_initialised = true;

  // deconflict session ID
  unsigned sessionID = mediaType.GetDefinition()->GetDefaultSessionId();
  if (size() == 0) {
    if (sessionID == 0)
      sessionID = 1;
  }
  else {
    iterator r = begin();
    while (r != end()) {
      if (r->second.preferredSessionId != sessionID)
        ++r;
      else {
        ++sessionID;
        r = begin();
      }
    }
  }

  AutoStartInfo info;
  info.autoStart = autoStart;
  info.preferredSessionId = sessionID;

  insert(value_type(mediaType, info));
}


OpalMediaType::AutoStartMode OpalConnection::AutoStartMap::GetAutoStart(const OpalMediaType & mediaType) const
{
  PWaitAndSignal m(m_mutex);
  const_iterator r = find(mediaType);
  return r == end() ? mediaType.GetAutoStart() : r->second.autoStart;
}


#if 0 //OPAL_HAS_IM

bool OpalConnection::TransmitInternalIM(const OpalMediaFormat & format, RTP_IMFrame & frame)
{
  // if the call contains any compatible IM stream, use it
  for (OpalMediaStreamPtr mediaStream(mediaStreams, PSafeReference); mediaStream != NULL; ++mediaStream) {
    if (mediaStream->IsSource() && (mediaStream->GetMediaFormat() == format)) {
      PTRACE(3, "OpalCon\tSending " << format << " IM message within call");
      return mediaStream->GetPatch()->PushFrame(frame);
    }
  }

  // otherwise push the frame directly to the other connection
  PSafePtr<OpalConnection> other = GetOtherPartyConnection();
  if (other != NULL) {
    PTRACE(3, "OpalCon\tSending " << format << " IM message directly to other connection");
    other->OnReceiveInternalIM(format, frame);
  }
  return true;
}


void OpalConnection::OnReceiveInternalIM(const OpalMediaFormat & format, RTP_IMFrame & rtp)
{
  TransmitExternalIM(format, rtp);
}


bool OpalConnection::TransmitExternalIM(const OpalMediaFormat & /*format*/, RTP_IMFrame & frame)
{
  PURL remotePartyURL, localPartyURL;
  PString remotePartyName;

  // get information about sender
  PSafePtr<OpalConnection> otherParty = GetOtherPartyConnectionAs<OpalConnection>();
  if (otherParty != NULL) {
    remotePartyURL  = otherParty->GetRemotePartyCallbackURL();
    remotePartyName = otherParty->GetRemotePartyName();
    localPartyURL   = otherParty->GetLocalPartyURL();
  }

  // pass information up the chain

  OpalIM message;
  message.m_conversationId = GetToken();
  message.m_to             = localPartyURL;
  message.m_from           = remotePartyURL;
  message.m_fromName       = remotePartyName;
  message.m_mimeType       = frame.GetContentType();

  T140String t140;
  frame.GetContent(t140);
  t140.AsString(message.m_body);

  endpoint.OnMessageReceived(message);

  return true;
}

bool OpalConnection::OnReceiveExternalIM(const OpalMediaFormat & format, RTP_IMFrame & body)
{
  return TransmitInternalIM(format, body);
}

#endif


void OpalConnection::StringOptions::ExtractFromURL(PURL & url)
{
  PStringToString params = url.GetParamVars();
  params.MakeUnique();
  for (PINDEX i = 0; i < params.GetSize(); ++i) {
    PCaselessString key = params.GetKeyAt(i);
    if (key.NumCompare(OPAL_URL_PARAM_PREFIX) == EqualTo) {
      SetAt(key.Mid(5), params.GetDataAt(i));
      url.SetParamVar(key, PString::Empty());
    }
  }
}

#if P_LUA

int OpalConnection::LuaSetOption(lua_State * /*lua*/)
{
  return 0;
}

#endif

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