src/rfc2833.cxx

   1 /*
   2  * rfc2833.cxx
   3  *
   4  * Open Phone Abstraction Library (OPAL)
   5  * Formally known as the Open H323 project.
   6  *
   7  * Copyright (c) 2001 Equivalence Pty. Ltd.
   8  *
   9  * The contents of this file are subject to the Mozilla Public License
  10  * Version 1.0 (the "License"); you may not use this file except in
  11  * compliance with the License. You may obtain a copy of the License at
  12  * http://www.mozilla.org/MPL/
  13  *
  14  * Software distributed under the License is distributed on an "AS IS"
  15  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
  16  * the License for the specific language governing rights and limitations
  17  * under the License.
  18  *
  19  * The Original Code is Open Phone Abstraction Library.
  20  *
  21  * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
  22  *
  23  * Contributor(s): ______________________________________.
  24  *
  25  * $Log$
  26  * Revision 1.4  2003/06/03 05:02:18  rjongbloed
  27  * Added comment and test for NULL pointer parameter.
  28  *
  29  * Revision 1.3  2002/05/08 04:39:57  robertj
  30  * Fixed problem with receiving RFC2833 data, was still trying to process it as
  31  *   codec and upsettign the channel receiver code.
  32  *
  33  * Revision 1.2  2002/02/19 06:32:38  robertj
  34  * Allowed for RTP filter functions to force output of packet, or prevent it
  35  *   from being sent overriding the n frames per packet algorithm.
  36  * Added more tracing.
  37  *
  38  * Revision 1.1  2002/01/23 05:06:23  robertj
  39  * Added RFC2833 support as separate class
  40  *
  41  */
  42
  43 #include <ptlib.h>
  44
  45 #ifdef __GNUC__
  46 #pragma implementation "rfc2833.h"
  47 #endif
  48
  49 #include "rfc2833.h"
  50
  51
  52 static const char RFC2833Table1Events[] = "0123456789*#ABCD!";
  53
  54
  55 #define new PNEW
  56
  57
  58 ///////////////////////////////////////////////////////////////////////////////
  59
  60 OpalRFC2833Info::OpalRFC2833Info(char t, unsigned d, unsigned ts)
  61 {
  62   tone = t;
  63   duration = d;
  64   timestamp = ts;
  65 }
  66
  67
  68 ///////////////////////////////////////////////////////////////////////////////
  69
  70 OpalRFC2833::OpalRFC2833(const PNotifier & rx)
  71   : receiveNotifier(rx),
  72 #ifdef _MSC_VER
  73 #pragma warning(disable:4355)
  74 #endif
  75     receiveHandler(PCREATE_NOTIFIER(ReceivedPacket)),
  76     transmitHandler(PCREATE_NOTIFIER(TransmitPacket))
  77 #ifdef _MSC_VER
  78 #pragma warning(default:4355)
  79 #endif
  80 {
  81   PTRACE(3, "RFC2833\tHandler created");
  82
  83   payloadType = RTP_DataFrame::IllegalPayloadType;
  84   receiveComplete = TRUE;
  85   receiveTimestamp = 0;
  86   receiveTimer.SetNotifier(PCREATE_NOTIFIER(ReceiveTimeout));
  87
  88   transmitState = TransmitIdle;
  89   transmitTimestamp = 0;
  90   transmitTimer.SetNotifier(PCREATE_NOTIFIER(TransmitEnded));
  91 }
  92
  93
  94 BOOL OpalRFC2833::SendTone(char tone, unsigned duration)
  95 {
  96   if (!BeginTransmit(tone))
  97     return FALSE;
  98
  99   transmitTimer = duration;
 100   return TRUE;
 101 }
 102
 103
 104 BOOL OpalRFC2833::BeginTransmit(char tone)
 105 {
 106   PWaitAndSignal m(mutex);
 107
 108   const char * theChar = strchr(RFC2833Table1Events, tone);
 109   if (theChar == NULL) {
 110     PTRACE(1, "RFC2833\tInvalid tone character.");
 111     return FALSE;
 112   }
 113
 114   if (transmitState != TransmitIdle) {
 115     PTRACE(1, "RFC2833\tAttempt to send tone while currently sending.");
 116     return FALSE;
 117   }
 118
 119   transmitCode = (BYTE)(theChar-RFC2833Table1Events);
 120   transmitState = TransmitActive;
 121   transmitTimestamp = 0;
 122   PTRACE(3, "RFC2833\tBegin transmit tone='" << tone << '\'');
 123   return TRUE;
 124 }
 125
 126
 127 BOOL OpalRFC2833::EndTransmit()
 128 {
 129   PWaitAndSignal m(mutex);
 130
 131   if (transmitState != TransmitActive) {
 132     PTRACE(1, "RFC2833\tAttempt to stop send tone while not sending.");
 133     return FALSE;
 134   }
 135
 136   transmitState = TransmitEnding;
 137   PTRACE(3, "RFC2833\tEnd transmit tone='" << RFC2833Table1Events[transmitCode] << '\'');
 138   return TRUE;
 139 }
 140
 141
 142 void OpalRFC2833::OnStartReceive(char tone)
 143 {
 144   OpalRFC2833Info info(tone);
 145   receiveNotifier(info, 0);
 146 }
 147
 148
 149 void OpalRFC2833::OnEndReceive(char tone, unsigned duration, unsigned timestamp)
 150 {
 151   OpalRFC2833Info info(tone, duration, timestamp);
 152   receiveNotifier(info, 0);
 153 }
 154
 155
 156 void OpalRFC2833::ReceivedPacket(RTP_DataFrame & frame, INT)
 157 {
 158   if (frame.GetPayloadType() != payloadType)
 159     return;
 160
 161   PINDEX payloadSize = frame.GetPayloadSize();
 162   // Zero the payload size so the channel processing ignores this packet
 163   frame.SetPayloadSize(0);
 164
 165   if (payloadSize < 4) {
 166     PTRACE_IF(1, payloadSize > 0,
 167               "RFC2833\tIgnoring packet, too small: " << frame.GetPayloadSize());
 168     return;
 169   }
 170
 171   const BYTE * payload = frame.GetPayloadPtr();
 172   if (payload[0] >= sizeof(RFC2833Table1Events)-1) {
 173     PTRACE(2, "RFC2833\tIgnoring packet, unsupported event.");
 174     return;
 175   }
 176
 177   PWaitAndSignal m(mutex);
 178
 179   receivedTone = RFC2833Table1Events[payload[0]];
 180   receivedDuration = (payload[2]<<8) + payload[3];
 181
 182   unsigned timestamp = frame.GetTimestamp();
 183   if (receiveTimestamp != timestamp) {
 184     PTRACE(3, "RFC2833\tReceived start tone=" << receivedTone);
 185     OnStartReceive(receivedTone);
 186
 187     // Starting a new event.
 188     receiveTimestamp = timestamp;
 189     receiveComplete = FALSE;
 190     receiveTimer = 150;
 191   }
 192   else {
 193     receiveTimer = 150;
 194     if (receiveComplete) {
 195       PTRACE(3, "RFC2833\tIgnoring duplicate packet.");
 196       return;
 197     }
 198   }
 199
 200   if ((payload[1]&0x80) == 0) {
 201     PTRACE(1, "RFC2833\tIgnoring packet, not end of event.");
 202     return;
 203   }
 204
 205   receiveComplete = TRUE;
 206   receiveTimer.Stop();
 207
 208   PTRACE(3, "RFC2833\tReceived end tone=" << receivedTone << " duration=" << receivedDuration);
 209   OnEndReceive(receivedTone, receivedDuration, receiveTimestamp);
 210 }
 211
 212
 213 void OpalRFC2833::ReceiveTimeout(PTimer &, INT)
 214 {
 215   PWaitAndSignal m(mutex);
 216
 217   if (receiveComplete)
 218     return;
 219
 220   receiveComplete = TRUE;
 221   PTRACE(3, "RFC2833\tTimeout tone=" << receivedTone << " duration=" << receivedDuration);
 222   OnEndReceive(receivedTone, receivedDuration, receiveTimestamp);
 223 }
 224
 225
 226 void OpalRFC2833::TransmitPacket(RTP_DataFrame & frame, INT param)
 227 {
 228   if (transmitState == TransmitIdle)
 229     return;
 230
 231   // Set flag to force a packet to be sent.
 232   if (param != 0)
 233     *(BOOL *)param = TRUE;
 234
 235   PWaitAndSignal m(mutex);
 236
 237   //frame.SetMarker(transmitTimestamp == 0);
 238
 239   unsigned actualTimestamp = frame.GetTimestamp();
 240   if (transmitTimestamp == 0)
 241     transmitTimestamp = actualTimestamp;
 242   frame.SetTimestamp(transmitTimestamp);
 243
 244   frame.SetPayloadType(payloadType);
 245   frame.SetPayloadSize(4);
 246
 247   BYTE * payload = frame.GetPayloadPtr();
 248   payload[0] = transmitCode;
 249
 250   payload[1] = 7;  // Volume
 251   if (transmitState == TransmitEnding) {
 252     payload[1] |= 0x80;
 253     transmitState = TransmitIdle;
 254   }
 255
 256   unsigned duration = actualTimestamp - transmitTimestamp;
 257   payload[2] = (BYTE)(duration>>8);
 258   payload[3] = (BYTE) duration    ;
 259
 260   PTRACE(4, "RFC2833\tInserting packet: ts=" << transmitTimestamp
 261          << " code='" << RFC2833Table1Events[transmitCode] << "'"
 262             " duration=" << duration << ' '
 263          << (transmitState == TransmitIdle ? "ending" : "continuing"));
 264 }
 265
 266
 267 void OpalRFC2833::TransmitEnded(PTimer &, INT)
 268 {
 269   EndTransmit();
 270 }
 271
 272
 273 /////////////////////////////////////////////////////////////////////////////