[Live-devel] about mjpeg ondemandrtspserver

[Zhixue Zhang]

Hi, Ross Finlayson

I am trying to set up an MJPEGOnDemandRTSPServer. The following is my subsession's code. But When I tried OpenRTSP, I failed to get SDPDescription. Can you help me?





GXCJMPEGServerMediaSubsession* 
GXCJMPEGServerMediaSubsession::createNew( UsageEnvironment& env, 
			Boolean _reuseFirstSource, GXCBasicSource* _source)
{
	return new GXCJMPEGServerMediaSubsession( env, _reuseFirstSource, _source );
}

GXCJMPEGServerMediaSubsession
::GXCJMPEGServerMediaSubsession( UsageEnvironment& env,
						Boolean _reuseFirstSource, GXCBasicSource *_source )
						:OnDemandServerMediaSubsession( env, _reuseFirstSource ),
						fDoneFlag(0), fInputSource( _source )
															 
{
	
}

GXCJMPEGServerMediaSubsession::~GXCJMPEGServerMediaSubsession()
{
	
}

static void afterPlayingDummy( void* cliendata)
{
	GXCJMPEGServerMediaSubsession* subsess
		= ( GXCJMPEGServerMediaSubsession* )cliendata;
	// Signal the event loop that we're done:
	subsess->setDoneFlag();
}

static void checkForAuxSDPLine( void* clienData )
{
	GXCJMPEGServerMediaSubsession* subsess
		= (GXCJMPEGServerMediaSubsession*) clienData;
	subsess->checkForAuxSDPLine1();
}

void GXCJMPEGServerMediaSubsession::setDoneFlag()
{
	fDoneFlag = ~0;
}

void GXCJMPEGServerMediaSubsession::checkForAuxSDPLine1()
{
	if ( fDummyRTPSink->auxSDPLine() != NULL )
	{
		// Signal the event loop that we're done:
		setDoneFlag();
	} else {
		// try again after a brief delay:
		int uSecsToDelay = 100000; // 100 ms
		nextTask() = envir().taskScheduler().scheduleDelayedTask(uSecsToDelay,
			(TaskFunc*)checkForAuxSDPLine, this);
	}
}

char const* GXCJMPEGServerMediaSubsession
::getAuxSDPLine( RTPSink* rtpSink, FramedSource* inputSource )
{
	// Note: For MPEG-4 video files, the 'config' information isn't known
	// until we start reading the file.  This means that "rtpSink"s
	// "auxSDPLine()" will be NULL initially, and we need to start reading
	// data from our file until this changes.
	fDummyRTPSink = rtpSink;
    
	// Start reading the file:
	fDummyRTPSink->startPlaying(*inputSource, afterPlayingDummy, this);
    
	// Check whether the sink's 'auxSDPLine()' is ready:
	checkForAuxSDPLine(this);
    
	envir().taskScheduler().doEventLoop(&fDoneFlag);
    
	char const* auxSDPLine = fDummyRTPSink->auxSDPLine();
	return auxSDPLine;
}

FramedSource* GXCJMPEGServerMediaSubsession
::createNewStreamSource( unsigned /*cliendSessionId*/, unsigned& estBitrate)
{
	estBitrate = 500; // kbps, estimate

	// Create a framer for the Video Elementary Stream:
	return GXCJPEGFramerSource::createNew(envir(), fInputSource);
}

RTPSink* GXCJMPEGServerMediaSubsession
::createNewRTPSink( Groupsock* rtpGroupsock,
				   unsigned char /*rtpPayloadTypeIfDynamic*/,
				   FramedSource* /*inputSource*/)
{
	return JPEGVideoRTPSink::createNew( envir(), rtpGroupsock );
}	



And     GXCJPEGFramerSource is defined as following:

class GXCJPEGFramerSource: public JPEGVideoSource{
public:
	static GXCJPEGFramerSource* createNew(UsageEnvironment& env,
					 GXCBasicSource *_source,
					 unsigned preferredFrameSize = 0,
					 unsigned playTimePerFrame = 0);
	// "preferredFrameSize" == 0 means 'no preference'
	// "playTimePerFrame" is in microseconds
	
	unsigned fileSize() const { return fFileSize; }
    // 0 means zero-length, unbounded, or unknown
	u_int8_t type() { return 1;}
	u_int8_t qFactor() {return 1;}
	u_int8_t width() {return 44;} // # pixels/8 (or 0 for 2048 pixels)
	u_int8_t height() {return 36;} // # pixels/8 (or 0 for 2048 pixels)

protected:
	GXCJPEGFramerSource(UsageEnvironment& env,
		       GXCBasicSource *_source,
		       unsigned preferredFrameSize,
		       unsigned playTimePerFrame);
	// called only by createNew()
	virtual ~GXCJPEGFramerSource();

private:
	// redefined virtual functions:
	virtual void doGetNextFrame();

private:
	unsigned fPreferredFrameSize;
	unsigned fPlayTimePerFrame;
	unsigned fFileSize;
	FILE	 *fFid;
};				 
¡¡¡¡¡¡
thanks a lot.
¡¡¡¡¡¡¡¡¡¡Zhixue Zhang
¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡zhangzx at rcs-9000.com
¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡2005-12-06