Live555实现数据RTSP流的推送

布满荆棘的人生 2024-02-23 01:51 8阅读 0赞

Live555是使用c++编写的RTSP开源库，以文件为载体进行推流，其中实现了多种类型的音频以及视频的流化。

简述RTSP  
RTSP是一种媒体传输协议，基于TCP协议，主要功能为媒体播放的控制以及开始连接时的握手操作。时间流传输走的时RTP协议，流传输控制协议走的是RTCP，RTP和RTCP具体使用TCP还是UDP，有RTSP SETUP阶段根据客户端选择而定。

实现自定义数据流传输  
首先实现一个比较通用的MediaSubsession，继承OnDemandServerMediaSubsession

class ComMediaSubsession:public OnDemandServerMediaSubsession 
    {
    	public:
    		static ComMediaSubsession* createNew(UsageEnvironment& env, int streamType, int videoType, int channelNO, 
    				bool reuseFirstSource, portNumBits initalNumPort = 6970);
    	protected:
    		ComMediaSubsession(UsageEnvironment& env, int streamType, int videoType, int channelNO, 
    				bool reuseFirstSource, portNumBits initalNumPort);
    		~ComMediaSubsession();
    		
    	protected:
    		// virtual function  new source and rtplink
    		FramedSource* createNewStreamSource(unsigned clientsessionId, unsigned& estBitrate);
    		RTPSink* createNewRTPSink(Groupsock* rtpGroupsock, unsigned char rtpPayloadTypeIfDynamic, FramedSource* inputSource);
    	
    	public:
    		int fStreamType;
    		int fVideoType;
    		int fChannelNO;
    		
    };

#include "ComMediaSubsession.h"
    #include "ComFrameSource.h"
    #include "H264VideoStreamFramer.hh"
    #include "H264VideoRTPSink.hh"
    #include "MP3ADURTPSink.hh"
    #include "MPEG1or2AudioRTPSink.hh"
    
    
    ComMediaSubsession::ComMediaSubsession(UsageEnvironment& env, int streamType, int videoType, int channelNO, bool reuseFirstSource, portNumBits initalNumPort)
    	:OnDemandServerMediaSubsession(env, reuseFirstSource), fStreamType(streamType), fVideoType(videoType), fChannelNO(channelNO)
    {
    }
    
    ComMediaSubsession::~ComMediaSubsession()
    {
    
    }
    
    
    ComMediaSubsession* DemoH264MediaSubsession::createNew(UsageEnvironment& env, int streamType, int videoType, int channelNO, 
    		bool reuseFirstSource, portNumBits initalNumPort)
    {
    	ComMediaSubsession* sms = new ComMediaSubsession(env, streamType, videoType, channelNO, reuseFirstSource, initalNumPort);
    	return sms;
    }
    
    
    FramedSource* ComMediaSubsession::createNewStreamSource(unsigned clientsessionId, unsigned& estBitrate)
    {
    	if(fVideoType == 0x01)
    	{ 
    	    // H264 video 
    		estBitrate = 2000; // kbps 
    		ComFrameSource * source = ComFrameSource::createNew(envir(), fStreamType, fChannelNO, 0);
    		if ( source == NULL )
    		{
    			DBG_LIVE555_PRINT("create source failed videoType:%d!\n", fVideoType );
    			return NULL;
    		}
    		return H264VideoStreamFramer::createNew(envir(), source);
    	}
    	else if ( fVideoType == 0x2) 
    	{   
    	    // Mpeg-4 video  
    	    estBitrate = 128; // kbps 
    		ComFrameSource * source = ComFrameSource::createNew(envir(), fStreamType, fChannelNO, 1);
    		if ( source == NULL )
    		{
    			DBG_LIVE555_PRINT("create source failed videoType:%d!\n", fVideoType );
    			return NULL;
    		}
    		return source;
    	}
    	return NULL;	
    }
    
    
    RTPSink* ComMediaSubsession::createNewRTPSink(Groupsock* rtpGroupsock, unsigned char rtpPayloadTypeIfDynamic, FramedSource* inputSource)
    {
    	if( fVideoType == 0x01)
    	{
    	    // H264 video
    		return H264VideoRTPSink::createNew(envir(), rtpGroupsock, rtpPayloadTypeIfDynamic);
    		
    	}
    	else if( fVideoType == 0x02)
    	{ 
    	    //  Mpeg-4
    		return MP3ADURTPSink::createNew(envir(), rtpGroupsock,rtpPayloadTypeIfDynamic);
    	}
        return NULL;
    }

接着实现数据获取类

#include "FramedSource.hh"
    
    class ComFrameSource:public FramedSource 
    {
    	public:
    		static ComFrameSource* createNew(UsageEnvironment& env, int streamtype, int channelno, int sourceType); 
    	protected:
    		ComFrameSource(UsageEnvironment& env, long sourceHandle, int sourceType);
    		~ComFrameSource();
    	private:
    		virtual void doGetNextFrame();
    	public:
    		void doStopGetFrame();
    	public:
    		unsigned fLastBufSize;
    		unsigned fLeftDataSize;
    		int fSourceType;
    		int fFirstFrame;
    		
    };

#include "ComFrameSource.h"
    
    ComFrameSource::ComFrameSource(UsageEnvironment& env,  int sourceType):
    	FramedSource(env), fLastBufSize(0), fLeftDataSize(0), fSourceType(sourceType), fFirstFrame(1)
    {
     
    }
    
    
    ComFrameSource::~ComFrameSource()
    { 
    
    }
    
    
    ComFrameSource* ComFrameSource::createNew(UsageEnvironment& env, int streamType, int channelNO, int sourceType)
    {
    	
    	return new ComFrameSource(env, sourceType);
    	
    }
    
    
    
    void ComFrameSource::doGetNextFrame()
    {
    	int ret = 0;
    
        /*实现获取数据到fTo，最大fMaxSize*/
    	ret = getStreamData(fSourceHandle, (char *)fTo, fMaxSize);
    	if (ret <= 0)
    	{
    	    fFrameSize = 0;
    		nextTask() = envir().taskScheduler().scheduleDelayedTask(10,
    				  (TaskFunc*)FramedSource::afterGetting, this);
    		return;
    	}
    
    	gettimeofday(&fPresentationTime, NULL);
    	
    	
    	// Switch to another task, and inform the reader that he has data:
    	nextTask() = envir().taskScheduler().scheduleDelayedTask(10,
    				  (TaskFunc*)FramedSource::afterGetting, this);
    
    
    
    }
    
    void ComFrameSource::doStopGetFrame()
    {
    
    }