rtspclient.cpp

流媒体传输协议的实现代码,非常有用.可以支持rtsp mms等流媒体传输协议

    // Look for a "Session:" header (to set our session id), and
    // a "Transport: " header (to set the server address/port)
    // For now, ignore other headers.
    char* lineStart;
    char* sessionId = new char[fResponseBufferSize]; // ensures we have enough space
    while (1) {
      lineStart = nextLineStart;
      if (lineStart == NULL) break;

      nextLineStart = getLine(lineStart);

      if (sscanf(lineStart, "Session: %[^;]", sessionId) == 1) {
	subsession.sessionId = strDup(sessionId);
	delete[] fLastSessionId; fLastSessionId = strDup(sessionId);
	continue;
      }

      char* serverAddressStr;
      portNumBits serverPortNum;
      unsigned char rtpChannelId, rtcpChannelId;
      if (parseTransportResponse(lineStart,
				 serverAddressStr, serverPortNum,
				 rtpChannelId, rtcpChannelId)) {
	delete[] subsession.connectionEndpointName();
	subsession.connectionEndpointName() = serverAddressStr;
	subsession.serverPortNum = serverPortNum;
	subsession.rtpChannelId = rtpChannelId;
	subsession.rtcpChannelId = rtcpChannelId;
	continue;
      }
    } 
    delete[] sessionId;

    if (subsession.sessionId == NULL) {
      envir().setResultMsg("\"Session:\" header is missing in the response");
      break;
    }

    if (streamUsingTCP) {
      // Tell the subsession to receive RTP (and send/receive RTCP)
      // over the RTSP stream:
      if (subsession.rtpSource() != NULL)
	subsession.rtpSource()->setStreamSocket(fInputSocketNum,
						subsession.rtpChannelId);
      if (subsession.rtcpInstance() != NULL)
	subsession.rtcpInstance()->setStreamSocket(fInputSocketNum,
						   subsession.rtcpChannelId);
    } else {
      // Normal case.
      // Set the RTP and RTCP sockets' destination address and port
      // from the information in the SETUP response: 
      subsession.setDestinations(fServerAddress);
    }

    delete[] cmd;
    return True;
  } while (0);

  delete[] cmd;
  return False;
}

static char* createScaleString(float scale, float currentScale) {
  char buf[100];
  if (scale == 1.0f && currentScale == 1.0f) {
    // This is the default value; we don't need a "Scale:" header:
    buf[0] = '\0';
  } else {
    sprintf(buf, "Scale: %f\r\n", scale);
  }

  return strDup(buf);
}
      
static char* createRangeString(float start, float end) {
  char buf[100];
  if (start < 0) {
    // We're resuming from a PAUSE; there's no "Range:" header at all
    buf[0] = '\0';
  } else if (end < 0) {
    // There's no end time:
    sprintf(buf, "Range: npt=%.3f-\r\n", start);
  } else {
    // There's both a start and an end time; include them both in the "Range:" hdr
    sprintf(buf, "Range: npt=%.3f-%.3f\r\n", start, end);
  }

  return strDup(buf);
}
      
static char const* NoSessionErr = "No RTSP session is currently in progress\n";

Boolean RTSPClient::playMediaSession(MediaSession& session,
				     float start, float end, float scale) {
#ifdef SUPPORT_REAL_RTSP
  if (session.isRealNetworksRDT) {
    // This is a RealNetworks stream; set the "Subscribe" parameter before proceeding:
    char* streamRuleString = RealGetSubscribeRuleString(&session);
    setMediaSessionParameter(session, "Subscribe", streamRuleString);
    delete[] streamRuleString;
  }
#endif
  char* cmd = NULL;
  do {
    // First, make sure that we have a RTSP session in progress
    if (fLastSessionId == NULL) {
      envir().setResultMsg(NoSessionErr);
      break;
    }

    // Send the PLAY command:

    // First, construct an authenticator string:
    char* authenticatorStr
      = createAuthenticatorString(&fCurrentAuthenticator, "PLAY", fBaseURL);
    // And then a "Scale:" string:
    char* scaleStr = createScaleString(scale, session.scale());
    // And then a "Range:" string:
    char* rangeStr = createRangeString(start, end);

    char* const cmdFmt =
      "PLAY %s RTSP/1.0\r\n"
      "CSeq: %d\r\n"
      "Session: %s\r\n"
      "%s"
      "%s"
      "%s"
      "%s"
      "\r\n";

    unsigned cmdSize = strlen(cmdFmt)
      + strlen(fBaseURL)
      + 20 /* max int len */
      + strlen(fLastSessionId)
      + strlen(scaleStr)
      + strlen(rangeStr)
      + strlen(authenticatorStr)
      + fUserAgentHeaderStrSize;
    cmd = new char[cmdSize];
    sprintf(cmd, cmdFmt,
	    fBaseURL,
	    ++fCSeq,
	    fLastSessionId,
	    scaleStr,
	    rangeStr,
	    authenticatorStr,
	    fUserAgentHeaderStr);
    delete[] scaleStr;
    delete[] rangeStr;
    delete[] authenticatorStr;

    if (!sendRequest(cmd, "PLAY")) break;

    // Get the response from the server:
    unsigned bytesRead; unsigned responseCode;
    char* firstLine; char* nextLineStart;
    if (!getResponse("PLAY", bytesRead, responseCode, firstLine, nextLineStart)) break;

    // Look for various headers that we understand:
    char* lineStart;
    while (1) {
      lineStart = nextLineStart;
      if (lineStart == NULL) break;

      nextLineStart = getLine(lineStart);

      if (parseScaleHeader(lineStart, session.scale())) break;
    }

    delete[] cmd;
    return True;
  } while (0);

  delete[] cmd;
  return False;
}

Boolean RTSPClient::playMediaSubsession(MediaSubsession& subsession,
					float start, float end, float scale,
					Boolean hackForDSS) {
  char* cmd = NULL;
  do {
    // First, make sure that we have a RTSP session in progress
    if (subsession.sessionId == NULL) {
      envir().setResultMsg(NoSessionErr);
      break;
    }

    // Send the PLAY command:

    // First, construct an authenticator string:
    char* authenticatorStr
      = createAuthenticatorString(&fCurrentAuthenticator, "PLAY", fBaseURL);
    // And then a "Scale:" string:
    char* scaleStr = createScaleString(scale, subsession.scale());
    // And then a "Range:" string:
    char* rangeStr = createRangeString(start, end);

    char* const cmdFmt =
      "PLAY %s%s%s RTSP/1.0\r\n"
      "CSeq: %d\r\n"
      "Session: %s\r\n"
      "%s"
      "%s"
      "%s"
      "%s"
      "\r\n";

    char const *prefix, *separator, *suffix;
    constructSubsessionURL(subsession, prefix, separator, suffix);
    if (hackForDSS || fServerIsKasenna) {
      // When "PLAY" is used to inject RTP packets into a DSS
      // (violating the RTSP spec, btw; "RECORD" should have been used)
      // the DSS can crash (or hang) if the '/trackid=...' portion of
      // the URL is present.
      separator = suffix = "";
    }

    unsigned cmdSize = strlen(cmdFmt)
      + strlen(prefix) + strlen(separator) + strlen(suffix)
      + 20 /* max int len */
      + strlen(subsession.sessionId)
      + strlen(scaleStr)
      + strlen(rangeStr)
      + strlen(authenticatorStr)
      + fUserAgentHeaderStrSize;
    cmd = new char[cmdSize];
    sprintf(cmd, cmdFmt,
	    prefix, separator, suffix,
	    ++fCSeq,
	    subsession.sessionId,
	    scaleStr,
	    rangeStr,
	    authenticatorStr,
	    fUserAgentHeaderStr);
    delete[] scaleStr;
    delete[] rangeStr;
    delete[] authenticatorStr;

    if (!sendRequest(cmd, "PLAY")) break;

    // Get the response from the server:
    unsigned bytesRead; unsigned responseCode;
    char* firstLine; char* nextLineStart;
    if (!getResponse("PLAY", bytesRead, responseCode, firstLine, nextLineStart)) break;

    // Look for various headers that we understand:
    char* lineStart;
    while (1) {
      lineStart = nextLineStart;
      if (lineStart == NULL) break;

      nextLineStart = getLine(lineStart);

      if (parseRTPInfoHeader(lineStart,
			     subsession.rtpInfo.trackId,
			     subsession.rtpInfo.seqNum,
			     subsession.rtpInfo.timestamp)) {
	continue;
      }
      if (parseScaleHeader(lineStart, subsession.scale())) continue;
    }

    delete[] cmd;
    return True;
  } while (0);

  delete[] cmd;
  return False;
}

Boolean RTSPClient::pauseMediaSession(MediaSession& session) {
  char* cmd = NULL;
  do {
    // First, make sure that we have a RTSP session in progress
    if (fLastSessionId == NULL) {
      envir().setResultMsg(NoSessionErr);
      break;
    }

    // Send the PAUSE command:

    // First, construct an authenticator string:
    char* authenticatorStr
      = createAuthenticatorString(&fCurrentAuthenticator, "PAUSE", fBaseURL);

    char* const cmdFmt =
      "PAUSE %s RTSP/1.0\r\n"
      "CSeq: %d\r\n"
      "Session: %s\r\n"
      "%s"
      "%s"
      "\r\n";

    unsigned cmdSize = strlen(cmdFmt)
      + strlen(fBaseURL)
      + 20 /* max int len */
      + strlen(fLastSessionId)
      + strlen(authenticatorStr)
      + fUserAgentHeaderStrSize;
    cmd = new char[cmdSize];
    sprintf(cmd, cmdFmt,
	    fBaseURL,
	    ++fCSeq,
	    fLastSessionId,
	    authenticatorStr,
	    fUserAgentHeaderStr);
    delete[] authenticatorStr;

    if (!sendRequest(cmd, "PAUSE")) break;

    if (fTCPStreamIdCount == 0) { // When TCP streaming, don't look for a response
      // Get the response from the server:
      unsigned bytesRead; unsigned responseCode;
      char* firstLine; char* nextLineStart;
      if (!getResponse("PAUSE", bytesRead, responseCode, firstLine, nextLineStart)) break;
    }

    delete[] cmd;
    return True;
  } while (0);

  delete[] cmd;
  return False;
}

Boolean RTSPClient::pauseMediaSubsession(MediaSubsession& subsession) {
  char* cmd = NULL;
  do {
    // First, make sure that we have a RTSP session in progress
    if (subsession.sessionId == NULL) {
      envir().setResultMsg(NoSessionErr);
      break;
    }
    
    // Send the PAUSE command:
    
    // First, construct an authenticator string:
    char* authenticatorStr
      = createAuthenticatorString(&fCurrentAuthenticator, "PAUSE", fBaseURL);
    
    char* const cmdFmt =
      "PAUSE %s%s%s RTSP/1.0\r\n"
      "CSeq: %d\r\n"
      "Session: %s\r\n"
      "%s"
      "%s"
      "\r\n";
    
    char const *prefix, *separator, *suffix;
    constructSubsessionURL(subsession, prefix, separator, suffix);
    if (fServerIsKasenna) separator = suffix = "";

    unsigned cmdSize = strlen(cmdFmt)
      + strlen(prefix) + strlen(separator) + strlen(suffix)
      + 20 /* max int len */
      + strlen(subsession.sessionId)
      + strlen(authenticatorStr)
      + fUserAgentHeaderStrSize;
    cmd = new char[cmdSize];
    sprintf(cmd, cmdFmt,
	    prefix, separator, suffix,
	    ++fCSeq,
	    subsession.sessionId,
	    authenticatorStr,
	    fUserAgentHeaderStr);
    delete[] authenticatorStr;
    
    if (!sendRequest(cmd, "PAUSE")) break;
    
    if (fTCPStreamIdCount == 0) { // When TCP streaming, don't look for a response
      // Get the response from the server:
      unsigned bytesRead; unsigned responseCode;
      char* firstLine; char* nextLineStart;
      if (!getResponse("PAUSE", bytesRead, responseCode, firstLine, nextLineStart)) break;
    }
      
    delete[] cmd;
    return True;
  } while (0);
  
  delete[] cmd;
  return False;
}

Boolean RTSPClient::recordMediaSubsession(MediaSubsession& subsession) {
  char* cmd = NULL;
  do {
    // First, make sure that we have a RTSP session in progress
    if (subsession.sessionId == NULL) {
      envir().setResultMsg(NoSessionErr);
      break;
    }

    // Send the RECORD command:

    // First, construct an authenticator string:
    char* authenticatorStr
      = createAuthenticatorString(&fCurrentAuthenticator,
				  "RECORD", fBaseURL);

    char* const cmdFmt =
      "RECORD %s%s%s RTSP/1.0\r\n"
      "CSeq: %d\r\n"
      "Session: %s\r\n"
      "Range: npt=0-\r\n"
      "%s"
      "%s"
      "\r\n";

    char const *prefix, *separator, *suffix;
    constructSubsessionURL(subsession, prefix, separator, suffix);

    unsigned cmdSize = strlen(cmdFmt)
      + strlen(prefix) + strlen(separator) + strlen(suffix)
      + 20 /* max int len */