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。
代码如下，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*200
static 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H264LiveVideoServerMediaSubssion
rtspServer->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 class
H264LiveVideoServerMediaSubssion(UsageEnvironment& env, Boolean reuseFirstSource, int *datasize, unsigned char* databuf, bool *dosent);
~H264LiveVideoServerMediaSubssion();
protected: // redefined virtual functions
FramedSource* 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
H264FramedLiveSource.hh
#ifndef _H264FRAMEDLIVESOURCE_HH
#define _H264FRAMEDLIVESOURCE_HH
#include <FramedSource.hh>
class H264FramedLiveSource : public FramedSource
{
public:
static H264FramedLiveSource* createNew(UsageEnvironment& env, int *datasize, unsigned char* databuf, bool *dosent, unsigned preferredFrameSize = 0, unsigned playTimePerFrame = 0);
protected:
H264FramedLiveSource(UsageEnvironment& env, int *datasize, unsigned char* databuf, bool *dosent, unsigned preferredFrameSize, unsigned playTimePerFrame);