庖丁解⽜-----Live555源码彻底解密（根据MediaServer讲解Rtsp的建⽴过程）live555MediaServer.cpp服务端源码讲解int main(int argc, char** argv) {// Begin by setting up our usage environment:TaskScheduler* scheduler = BasicTaskScheduler::createNew();UsageEnvironment* env = BasicUsageEnvironment::createNew(*scheduler);UserAuthenticationDatabase* authDB = NULL;// Create the RTSP server. Try first with the default port number (554),// and then with the alternative port number (8554):RTSPServer* rtspServer;portNumBits rtspServerPortNum = 554;//先使⽤554默认端⼝建⽴Rtsp ServerrtspServer = DynamicRTSPServer::createNew(*env, rtspServerPortNum, authDB);//如果建⽴不成功，使⽤8554建⽴rtsp serverif (rtspServer == NULL) {rtspServerPortNum = 8554;rtspServer = DynamicRTSPServer::createNew(*env, rtspServerPortNum, authDB);}if (rtspServer == NULL) {*env << "Failed to create RTSP server: " << env->getResultMsg() << "\n";// exit(1);return -1;}env->taskScheduler().doEventLoop(); // does not returnreturn 0; // only to prevent compiler warning}跟踪进⼊CreateNew函数;DynamicRTSPServer*DynamicRTSPServer::createNew(UsageEnvironment&env,PortourPort,UserAuthenticationDatabase*authDatabase,unsigned reclamationTestSeconds) {if (ourSocket == -1)returnNULL;return new DynamicRTSPServer(env,ourSocket,ourPort,authDatabase,reclamationTestSeconds);}DynamicRTSPServer::DynamicRTSPServer(UsageEnvironment&env,intourSocket,Port ourPort,UserAuthenticationDatabase*authDatabase,unsignedreclamationTestSeconds): RTSPServerSupportingHTTPStreaming(env,ourSocket,ourPort,authDatabase,reclamationTestSeconds) {}⾸先建⽴socket，然后在调⽤DynamicRtspServer的构造函数，DynamicRtspServer继承RTSPServerSupportingHTTPStreaming类; RTSPServerSupportingHTTPStreaming类⼜继承RTSPServer类；RTSPServerSupportingHTTPStreaming类的主要作⽤是⽀持Http；接着看setUpOurSocket函数在前⾯已经讲过；就是建⽴socket；最后我们跟踪进⼊RTSPServer类的构造函数：RTSPServer::RTSPServer(UsageEnvironment& env,int ourSocket, Port ourPort,UserAuthenticationDatabase* authDatabase,unsigned reclamationTestSeconds): Medium(env),fRTSPServerPort(ourPort), fRTSPServerSocket(ourSocket), fHTTPServerSocket(-1), fHTTPServerPort(0),fServerMediaSessions(HashTable::create(STRING_HASH_KEYS)),fClientConnections(HashTable::create(ONE_WORD_HASH_KEYS)),fClientConnectionsForHTTPTunneling(NULL), // will get created if neededfClientSessions(HashTable::create(STRING_HASH_KEYS)),fPendingRegisterRequests(HashTable::create(ONE_WORD_HASH_KEYS)),fAuthDB(authDatabase), fReclamationTestSeconds(reclamationTestSeconds) {ignoreSigPipeOnSocket(ourSocket); // so that clients on the same host that are killed don't also kill us// Arrange to handle connections from others:env.taskScheduler().turnOnBackgroundReadHandling(fRTSPServerSocket,(TaskScheduler::BackgroundHandlerProc*)&incomingConnectionHandlerRTSP,this);}当fRTSPServerSocket收到数据时，调⽤incomingConnectionHandlerRTSP回调函数，继续跟进到incomingConnectionHandlerRTSP函void RTSPServer::incomingConnectionHandlerRTSP(void* instance,int/*mask*/) {RTSPServer* server = (RTSPServer*)instance;server->incomingConnectionHandlerRTSP1();}void RTSPServer::incomingConnectionHandler(int serverSocket) {struct sockaddr_in clientAddr;SOCKLEN_T clientAddrLen = sizeof clientAddr;int clientSocket = accept(serverSocket, (struct sockaddr*)&clientAddr, &clientAddrLen);if (clientSocket < 0) {int err = envir().getErrno();if (err != EWOULDBLOCK) {envir().setResultErrMsg("accept() failed: ");}return;}makeSocketNonBlocking(clientSocket);increaseSendBufferTo(envir(), clientSocket, 50*1024);#ifdef DEBUGenvir() << "accept()ed connection from " << AddressString(clientAddr).val() << "\n";#endif// Create a new object for handling this RTSP connection:(void)createNewClientConnection(clientSocket, clientAddr);}当收到客户的连接时需保存下代表客户端的新socket，以后⽤这个socket与这个客户通讯。
