文如其名，最近在做的项目要求利用RTSP协议转发处理完的H264视频数据给上一层客户端，环境是Windows的VS2013，于是就各种百度谷歌找代码。结果在得到利用live555去做比较简单的结论的同时也悲情地发现，网上别人贴出来的代码基本都是Linux上面的。在修改了两份来适用于Windows无效后，又一次陷入了百度谷歌的无尽搜索中。Anyway，最后终于解决了，所以贴出代码跟大家分享下，希望能给和我需求相似的童鞋一点启发，也希望有高手指正其中的问题。
用live555进行RTSP的播放基本上是通过修改其给出来的播放本地文件的DEMO来实现的。但由于其DEMO封装的比较深，所以要直接修改他的fread处的代码变成内存拷贝来实现实时传输会显得比较别扭。本文参考了网上的一些代码，自定义了一个继承自H264VideoFileServerMediaSubsession的类来来进行处理，同时定义了一个继承自FramedSource的类来做内存的拷贝操作，该类亦是区别于读本地文件和实时流之紧要处。
一口气杂七杂八说了好多，，下面贴出代码吧。如果觉得需要或者懒得自己搭建live555的环境亦可以在文中最后的链接中下载该工程（环境为VS2013），如果你的VS版本合适即可直接运行。
主文件（程序入口）
#include "H264LiveVideoServerMediaSubssion.hh"#include "H264FramedLiveSource.hh"#include "liveMedia.hh"#include "BasicUsageEnvironment.hh"#define BUFSIZE 1024*200static void announceStream(RTSPServer* rtspServer, ServerMediaSession* sms,char const* streamName)//显示RTSP连接信息{char* url = rtspServer->rtspURL(sms);UsageEnvironment& env = rtspServer->envir();env <<streamName<< "\n";env << "Play this stream using the URL \&;" << url << "\&;\n";delete[] url;}int main(int argc, char** argv) {//设置环境UsageEnvironment* env;Boolean reuseFirstSource = False;//如果为“true”则其他接入的客户端跟第一个客户端看到一样的视频流，否则其他客户端接入的时候将重新播放TaskScheduler* scheduler = BasicTaskScheduler::createNew();env = BasicUsageEnvironment::createNew(*scheduler);//创建RTSP服务器UserAuthenticationDatabase* authDB = NULL;RTSPServer* rtspServer = RTSPServer::createNew(*env, 8554, authDB);if (rtspServer == NULL) {*env << "Failed to create RTSP server: " << env->getResultMsg() << "\n";exit(1);}char const* descriptionString= "Session streamed by \&;testOnDemandRTSPServer\&;";//模拟实时流发送相关变量int datasize;//数据区长度unsigned char* databuf;//数据区指针databuf = (unsigned char*)malloc(1024*1024);bool dosent;//rtsp发送标志位，为true则发送，否则退出//从文件中拷贝1M数据到内存中作为实时网络传输内存模拟，如果实时网络传输应该是双线程结构，记得在这里加上线程锁//此外实时传输的数据拷贝应该是发生在H264FramedLiveSource文件中，所以这里只是自上往下的传指针过去给它FILE *pf;fopen_s(&pf, "test.264", "rb");fread(databuf, 1, BUFSIZE, pf);datasize = BUFSIZE;dosent = true;fclose(pf);//上面的部分除了模拟网络传输的部分外其他的基本跟live555提供的demo一样，而下面则修改为网络传输的形式，为此重写addSubsession的第一个参数相关文件char const* streamName = "h264ESVideoTest";ServerMediaSession* sms = ServerMediaSession::createNew(*env, streamName, streamName,descriptionString);sms->addSubsession(H264LiveVideoServerMediaSubssion::createNew(*env, reuseFirstSource, &datasize, databuf,&dosent));//修改为自己实现的H264LiveVideoServerMediaSubssionrtspServer->addServerMediaSession(sms);announceStream(rtspServer, sms, streamName);//提示用户输入连接信息env->taskScheduler().doEventLoop(); //循环等待连接free(databuf);//释放掉内存return 0;}自定义H264VideoFileServerMediaSubsession类
H264VideoFileServerMediaSubsession.hh
#ifndef _H264_LIVE_VIDEO_SERVER_MEDIA_SUBSESSION_HH#define _H264_LIVE_VIDEO_SERVER_MEDIA_SUBSESSION_HH#include "H264VideoFileServerMediaSubsession.hh"class H264LiveVideoServerMediaSubssion : public H264VideoFileServerMediaSubsession {public:static H264LiveVideoServerMediaSubssion* createNew(UsageEnvironment& env, Boolean reuseFirstSource, int *datasize, unsigned char* databuf, bool *dosent);protected: // we're a virtual base classH264LiveVideoServerMediaSubssion(UsageEnvironment& env, Boolean reuseFirstSource, int *datasize, unsigned char* databuf, bool *dosent);~H264LiveVideoServerMediaSubssion();protected: // redefined virtual functionsFramedSource* createNewStreamSource(unsigned clientSessionId,unsigned& estBitrate);public:char fFileName[100];int *Server_datasize;//数据区大小指针unsigned char* Server_databuf;//数据区指针bool *Server_dosent;//发送标示};#endifH264VideoFileServerMediaSubsession.cpp#include "H264LiveVideoServerMediaSubssion.hh"#include "H264FramedLiveSource.hh"#include "H264VideoStreamFramer.hh"H264LiveVideoServerMediaSubssion* H264LiveVideoServerMediaSubssion::createNew(UsageEnvironment& env, Boolean reuseFirstSource, int *datasize, unsigned char* databuf, bool *dosent){return new H264LiveVideoServerMediaSubssion(env, reuseFirstSource, datasize, databuf, dosent);}H264LiveVideoServerMediaSubssion::H264LiveVideoServerMediaSubssion(UsageEnvironment& env, Boolean reuseFirstSource, int *datasize, unsigned char* databuf, bool *dosent): H264VideoFileServerMediaSubsession(env, fFileName, reuseFirstSource)//H264VideoFileServerMediaSubsession不是我们需要修改的文件，//但是我们又要用它来初始化我们的函数，//所以给个空数组进去即可{Server_datasize = datasize;//数据区大小指针Server_databuf = databuf;//数据区指针Server_dosent = dosent;//发送标示}H264LiveVideoServerMediaSubssion::~H264LiveVideoServerMediaSubssion(){}FramedSource* H264LiveVideoServerMediaSubssion::createNewStreamSource(unsigned clientSessionId, unsigned& estBitrate){/* Remain to do : assign estBitrate */estBitrate = 1000; // kbps, estimate//创建视频源H264FramedLiveSource* liveSource = H264FramedLiveSource::createNew(envir(), Server_datasize, Server_databuf, Server_dosent);if (liveSource == NULL){return NULL;}// Create a framer for the Video Elementary Stream:return H264VideoStreamFramer::createNew(envir(), liveSource);}自定义H264FramedLiveSource类人之所以有一张嘴，而有两只耳朵，原因是听的要比说的多一倍。
