artspclient.cpp

#define __STDC_CONSTANT_MACROS

#include "artspclient.h"
#include "artspinput.h"
#include "tools.h"

// A function that outputs a string that identifies each stream (for debugging output).  Modify this if you wish:
UsageEnvironment& operator<<(UsageEnvironment& env, const RTSPClient& rtspClient) {
  return env << "[URL:\"" << rtspClient.url() << "\"]: ";
}

// A function that outputs a string that identifies each subsession (for debugging output).  Modify this if you wish:
UsageEnvironment& operator<<(UsageEnvironment& env, const MediaSubsession& subsession) {
  return env << subsession.mediumName() << "/" << subsession.codecName();
}


RTSPClient * openURL(UsageEnvironment& env, char const* progName, char const* rtspURL, aRTSPInput* _pRTSPInput) {
  // Begin by creating a "RTSPClient" object.  Note that there is a separate "RTSPClient" object for each stream that we wish
  // to receive (even if more than stream uses the same "rtsp://" URL).
  //...
  RTSPClient* rtspClient = ourRTSPClient::createNew(env, rtspURL, RTSP_CLIENT_VERBOSITY_LEVEL, progName, 0, _pRTSPInput);
  if (rtspClient == NULL) {
    env << "Failed to create a RTSP client for URL \"" << rtspURL << "\": " << env.getResultMsg() << "\n";
    return NULL;
  }

//  ++rtspClientCount;
  _pRTSPInput->streamActive = true;

  // Next, send a RTSP "DESCRIBE" command, to get a SDP description for the stream.
  // Note that this command - like all RTSP commands - is sent asynchronously; we do not block, waiting for a response.
  // Instead, the following function call returns immediately, and we handle the RTSP response later, from within the event loop:
  rtspClient->sendDescribeCommand(continueAfterDESCRIBE);
  return rtspClient;
}


// Implementation of the RTSP 'response handlers':

void continueAfterDESCRIBE(RTSPClient* rtspClient, int resultCode, char* resultString) {
  do {
    UsageEnvironment& env = rtspClient->envir(); // alias
    StreamClientState& scs = ((ourRTSPClient*)rtspClient)->scs; // alias

    if (resultCode != 0) {
      env << *rtspClient << "Failed to get a SDP description: " << resultString << "\n";
      delete[] resultString;
      break;
    }

    char* const sdpDescription = resultString;
    env << *rtspClient << "Got a SDP description:\n" << sdpDescription << "\n";

    //...
    //ParseClipRect(sdpDescription);

    // Create a media session object from this SDP description:
    scs.session = MediaSession::createNew(env, sdpDescription);
    delete[] sdpDescription; // because we don't need it anymore
    if (scs.session == NULL) {
      env << *rtspClient << "Failed to create a MediaSession object from the SDP description: " << env.getResultMsg() << "\n";
      break;
    } else if (!scs.session->hasSubsessions()) {
      env << *rtspClient << "This session has no media subsessions (i.e., no \"m=\" lines)\n";
      break;
    }

    // Then, create and set up our data source objects for the session.  We do this by iterating over the session's 'subsessions',
    // calling "MediaSubsession::initiate()", and then sending a RTSP "SETUP" command, on each one.
    // (Each 'subsession' will have its own data source.)
    scs.iter = new MediaSubsessionIterator(*scs.session);
    setupNextSubsession(rtspClient);
    return;
  } while (0);

  // An unrecoverable error occurred with this stream.
  shutdownStream(rtspClient);
}

// By default, we request that the server stream its data using RTP/UDP.
// If, instead, you want to request that the server stream via RTP-over-TCP, change the following to True:
#define REQUEST_STREAMING_OVER_TCP False

void setupNextSubsession(RTSPClient* rtspClient) {
  UsageEnvironment& env = rtspClient->envir(); // alias
  StreamClientState& scs = ((ourRTSPClient*)rtspClient)->scs; // alias

  scs.subsession = scs.iter->next();
  if (scs.subsession != NULL) {
    if (!scs.subsession->initiate()) {
      env << *rtspClient << "Failed to initiate the \"" << *scs.subsession << "\" subsession: " << env.getResultMsg() << "\n";
      setupNextSubsession(rtspClient); // give up on this subsession; go to the next one
    } else {
      env << *rtspClient << "Initiated the \"" << *scs.subsession << "\" subsession (";
      if (scs.subsession->rtcpIsMuxed()) {
          env << "client port " << scs.subsession->clientPortNum();
      } else {
          env << "client ports " << scs.subsession->clientPortNum() << "-" << scs.subsession->clientPortNum()+1;
      }
      env << ")\n";

      // Continue setting up this subsession, by sending a RTSP "SETUP" command:
      rtspClient->sendSetupCommand(*scs.subsession, continueAfterSETUP, False, REQUEST_STREAMING_OVER_TCP);
    }
    return;
  }

  // We've finished setting up all of the subsessions.  Now, send a RTSP "PLAY" command to start the streaming:
  if (scs.session->absStartTime() != NULL) {
    // Special case: The stream is indexed by 'absolute' time, so send an appropriate "PLAY" command:
    rtspClient->sendPlayCommand(*scs.session, continueAfterPLAY, scs.session->absStartTime(), scs.session->absEndTime());
  } else {
    scs.duration = scs.session->playEndTime() - scs.session->playStartTime();
    rtspClient->sendPlayCommand(*scs.session, continueAfterPLAY);
  }
}

void continueAfterSETUP(RTSPClient* rtspClient, int resultCode, char* resultString) {
  do {
    UsageEnvironment& env = rtspClient->envir(); // alias
    StreamClientState& scs = ((ourRTSPClient*)rtspClient)->scs; // alias

    if (resultCode != 0) {
      env << *rtspClient << "Failed to set up the \"" << *scs.subsession << "\" subsession: " << resultString << "\n";
      break;
    }

    env << *rtspClient << "Set up the \"" << *scs.subsession << "\" subsession (";
    if (scs.subsession->rtcpIsMuxed()) {
      env << "client port " << scs.subsession->clientPortNum();
    } else {
      env << "client ports " << scs.subsession->clientPortNum() << "-" << scs.subsession->clientPortNum()+1;
    }
    env << ")\n";

    // Having successfully setup the subsession, create a data sink for it, and call "startPlaying()" on it.
    // (This will prepare the data sink to receive data; the actual flow of data from the client won't start happening until later,
    // after we've sent a RTSP "PLAY" command.)

    scs.subsession->sink = DummySink::createNew(env, *scs.subsession, rtspClient->url(), ((ourRTSPClient*)rtspClient)->pRTSPInput);
      // perhaps use your own custom "MediaSink" subclass instead
    if (scs.subsession->sink == NULL) {
      env << *rtspClient << "Failed to create a data sink for the \"" << *scs.subsession
	  << "\" subsession: " << env.getResultMsg() << "\n";
      break;
    }

    env << *rtspClient << "Created a data sink for the \"" << *scs.subsession << "\" subsession\n";
    scs.subsession->miscPtr = rtspClient; // a hack to let subsession handle functions get the "RTSPClient" from the subsession 
    scs.subsession->sink->startPlaying(*(scs.subsession->readSource()),
				       subsessionAfterPlaying, scs.subsession);
    // Also set a handler to be called if a RTCP "BYE" arrives for this subsession:
    if (scs.subsession->rtcpInstance() != NULL) {
      scs.subsession->rtcpInstance()->setByeHandler(subsessionByeHandler, scs.subsession);
    }
  } while (0);
  delete[] resultString;

  // Set up the next subsession, if any:
  setupNextSubsession(rtspClient);
}

void continueAfterPLAY(RTSPClient* rtspClient, int resultCode, char* resultString) {
  Boolean success = False;

  do {
    UsageEnvironment& env = rtspClient->envir(); // alias
    StreamClientState& scs = ((ourRTSPClient*)rtspClient)->scs; // alias

    if (resultCode != 0) {
      env << *rtspClient << "Failed to start playing session: " << resultString << "\n";
      break;
    }

    // Set a timer to be handled at the end of the stream's expected duration (if the stream does not already signal its end
    // using a RTCP "BYE").  This is optional.  If, instead, you want to keep the stream active - e.g., so you can later
    // 'seek' back within it and do another RTSP "PLAY" - then you can omit this code.
    // (Alternatively, if you don't want to receive the entire stream, you could set this timer for some shorter value.)
    if (scs.duration > 0) {
      unsigned const delaySlop = 2; // number of seconds extra to delay, after the stream's expected duration.  (This is optional.)
      scs.duration += delaySlop;
      unsigned uSecsToDelay = (unsigned)(scs.duration*1000000);
      scs.streamTimerTask = env.taskScheduler().scheduleDelayedTask(uSecsToDelay, (TaskFunc*)streamTimerHandler, rtspClient);
    }

    env << *rtspClient << "Started playing session";
    if (scs.duration > 0) {
      env << " (for up to " << scs.duration << " seconds)";
    }
    env << "...\n";

    success = True;
  } while (0);
  delete[] resultString;

  if (!success) {
    // An unrecoverable error occurred with this stream.
    shutdownStream(rtspClient);
  }
}


// Implementation of the other event handlers:

void subsessionAfterPlaying(void* clientData) {
  MediaSubsession* subsession = (MediaSubsession*)clientData;
  RTSPClient* rtspClient = (RTSPClient*)(subsession->miscPtr);

  // Begin by closing this subsession's stream:
  Medium::close(subsession->sink);
  subsession->sink = NULL;

  // Next, check whether *all* subsessions' streams have now been closed:
  MediaSession& session = subsession->parentSession();
  MediaSubsessionIterator iter(session);
  while ((subsession = iter.next()) != NULL) {
    if (subsession->sink != NULL) return; // this subsession is still active
  }

  // All subsessions' streams have now been closed, so shutdown the client:
  shutdownStream(rtspClient);
}

void subsessionByeHandler(void* clientData) {
  MediaSubsession* subsession = (MediaSubsession*)clientData;
  RTSPClient* rtspClient = (RTSPClient*)subsession->miscPtr;
  UsageEnvironment& env = rtspClient->envir(); // alias

  env << *rtspClient << "Received RTCP \"BYE\" on \"" << *subsession << "\" subsession\n";

  // Now act as if the subsession had closed:
  subsessionAfterPlaying(subsession);
}

void streamTimerHandler(void* clientData) {
  ourRTSPClient* rtspClient = (ourRTSPClient*)clientData;
  StreamClientState& scs = rtspClient->scs; // alias

  scs.streamTimerTask = NULL;

  // Shut down the stream:
  shutdownStream(rtspClient);
}

void shutdownStream(RTSPClient* rtspClient, int exitCode) {
  UsageEnvironment& env = rtspClient->envir(); // alias
  StreamClientState& scs = ((ourRTSPClient*)rtspClient)->scs; // alias

  // First, check whether any subsessions have still to be closed:
  if (scs.session != NULL) { 
    Boolean someSubsessionsWereActive = False;
    MediaSubsessionIterator iter(*scs.session);
    MediaSubsession* subsession;

    while ((subsession = iter.next()) != NULL) {
      if (subsession->sink != NULL) {
	Medium::close(subsession->sink);
	subsession->sink = NULL;

	if (subsession->rtcpInstance() != NULL) {
	  subsession->rtcpInstance()->setByeHandler(NULL, NULL); // in case the server sends a RTCP "BYE" while handling "TEARDOWN"
	}

	someSubsessionsWereActive = True;
      }
    }

    if (someSubsessionsWereActive) {
      // Send a RTSP "TEARDOWN" command, to tell the server to shutdown the stream.
      // Don't bother handling the response to the "TEARDOWN".
      rtspClient->sendTeardownCommand(*scs.session, NULL);
    }
  }

  env << *rtspClient << "Closing the stream.\n";
  Medium::close(rtspClient);
    // Note that this will also cause this stream's "StreamClientState" structure to get reclaimed.

  ((ourRTSPClient*)rtspClient)->pRTSPInput->streamActive = false;

//  if (--rtspClientCount == 0) {
    // The final stream has ended, so exit the application now.
    // (Of course, if you're embedding this code into your own application, you might want to comment this out,
    // and replace it with "eventLoopWatchVariable = 1;", so that we leave the LIVE555 event loop, and continue running "main()".)
    // exit(exitCode);
//  }
}


// Implementation of "ourRTSPClient":

ourRTSPClient* ourRTSPClient::createNew(UsageEnvironment& env, char const* rtspURL,
					int verbosityLevel, char const* applicationName, portNumBits tunnelOverHTTPPortNum, aRTSPInput * _pRTSPInput) {
  return new ourRTSPClient(env, rtspURL, verbosityLevel, applicationName, tunnelOverHTTPPortNum, _pRTSPInput);
}

ourRTSPClient::ourRTSPClient(UsageEnvironment& env, char const* rtspURL,
			     int verbosityLevel, char const* applicationName, portNumBits tunnelOverHTTPPortNum, aRTSPInput* _pRTSPInput)
  : RTSPClient(env,rtspURL, verbosityLevel, applicationName, tunnelOverHTTPPortNum, -1) {
    pRTSPInput = _pRTSPInput;
}

ourRTSPClient::~ourRTSPClient() {
}


// Implementation of "StreamClientState":

StreamClientState::StreamClientState()
  : iter(NULL), session(NULL), subsession(NULL), streamTimerTask(NULL), duration(0.0) {
}

StreamClientState::~StreamClientState() {
  delete iter;
  if (session != NULL) {
    // We also need to delete "session", and unschedule "streamTimerTask" (if set)
    UsageEnvironment& env = session->envir(); // alias

    env.taskScheduler().unscheduleDelayedTask(streamTimerTask);
    Medium::close(session);
  }
}


// Implementation of "DummySink":

// Even though we're not going to be doing anything with the incoming data, we still need to receive it.
// Define the size of the buffer that we'll use:
#define DUMMY_SINK_RECEIVE_BUFFER_SIZE 3000000

DummySink* DummySink::createNew(UsageEnvironment& env, MediaSubsession& subsession, char const* streamId, aRTSPInput* _pRTSPInput) {
  return new DummySink(env, subsession, streamId, _pRTSPInput);
}

DummySink::DummySink(UsageEnvironment& env, MediaSubsession& subsession, char const* streamId, aRTSPInput* _pRTSPInput)
  : MediaSink(env),
    fSubsession(subsession) {
  fStreamId = strDup(streamId);
  fReceiveBuffer = new u_int8_t[DUMMY_SINK_RECEIVE_BUFFER_SIZE];
  pRTSPInput = _pRTSPInput;
}

DummySink::~DummySink() {
  delete[] fReceiveBuffer;
  delete[] fStreamId;
}

void DummySink::afterGettingFrame(void* clientData, unsigned frameSize, unsigned numTruncatedBytes,
				  struct timeval presentationTime, unsigned durationInMicroseconds) {
  DummySink* sink = (DummySink*)clientData;
  sink->afterGettingFrame(frameSize, numTruncatedBytes, presentationTime, durationInMicroseconds);
}

// If you don't want to see debugging output for each received frame, then comment out the following line:
//#define DEBUG_PRINT_EACH_RECEIVED_FRAME 1

void DummySink::afterGettingFrame(unsigned frameSize, unsigned numTruncatedBytes,
				  struct timeval presentationTime, unsigned /*durationInMicroseconds*/) {
  // We've just received a frame of data.  (Optionally) print out information about it:
#ifdef DEBUG_PRINT_EACH_RECEIVED_FRAME
  if (fStreamId != NULL) envir() << "Stream \"" << fStreamId << "\"; ";
  envir() << fSubsession.mediumName() << "/" << fSubsession.codecName() << ":\tReceived " << frameSize << " bytes";
  if (numTruncatedBytes > 0) envir() << " (with " << numTruncatedBytes << " bytes truncated)";
  char uSecsStr[6+1]; // used to output the 'microseconds' part of the presentation time
  sprintf(uSecsStr, "%06u", (unsigned)presentationTime.tv_usec);
  envir() << ".\tPresentation time: " << (int)presentationTime.tv_sec << "." << uSecsStr;
  if (fSubsession.rtpSource() != NULL && !fSubsession.rtpSource()->hasBeenSynchronizedUsingRTCP()) {
    envir() << "!"; // mark the debugging output to indicate that this presentation time is not RTCP-synchronized
  }
#ifdef DEBUG_PRINT_NPT
  envir() << "\tNPT: " << fSubsession.getNormalPlayTime(presentationTime);
#endif
  envir() << "\n";
#endif

  pRTSPInput->receiveFrame(fReceiveBuffer, frameSize);

  // Then continue, to request the next frame of data:
  continuePlaying();
}

Boolean DummySink::continuePlaying() {
  if (fSource == NULL) return False; // sanity check (should not happen)

  // Request the next frame of data from our input source.  "afterGettingFrame()" will get called later, when it arrives:
  fSource->getNextFrame(fReceiveBuffer, DUMMY_SINK_RECEIVE_BUFFER_SIZE,
                        afterGettingFrame, this,
                        onSourceClosure, this);
  return True;
}