1.设置RTSP端口号
设置RTSP端口号的处理位于ARTSPConnection.cpp文件中,首先从url中获取端口号,如果读取不到,则设置为默认端口554。代码处理如下:
ARTSPConnection::ParseURL( const char *colonPos = strchr(host->c_str(), ':'); if (colonPos != NULL) { unsigned long x; if (!ParseSingleUnsignedLong(colonPos + 1, &x) || x >= 65536) { // rtsp端口必须小于65536 return false; } *port = x; size_t colonOffset = colonPos - host->c_str(); size_t trailing = host->size() - colonOffset; host->erase(colonOffset, trailing); } else { *port = 554; // 如果从url中获取不到端口,则设置默认端口554 }--------------------------------------------------------------------------------------------------------
2.设置RTP和RTCP端口号
设置RTP和RTCP端口号的处理位于ARTPConnection.cpp文件中中,与设置RTSP端口号的处理分别在不同的文件中。
// Creates a pair of UDP datagram sockets bound to adjacent ports // (the rtpSocket is bound to an even port, the rtcpSocket to the // next higher port). static void MakePortPair( int *rtpSocket, int *rtcpSocket, unsigned *rtpPort);(2)函数定义:具体设置RTP和RTCP端口
// static void ARTPConnection::MakePortPair( int *rtpSocket, int *rtcpSocket, unsigned *rtpPort) { *rtpSocket = socket(AF_INET, SOCK_DGRAM, 0); CHECK_GE(*rtpSocket, 0); bumpSocketBufferSize(*rtpSocket); *rtcpSocket = socket(AF_INET, SOCK_DGRAM, 0); CHECK_GE(*rtcpSocket, 0); bumpSocketBufferSize(*rtcpSocket); unsigned start = (rand() * 1000)/ RAND_MAX + 15550; // 最小端口号为15550 start &= ~1; // 与1取反后的值做与操作,结果就是start变成偶数,端口从偶数开始 for (unsigned port = start; port < 65536; port += 2) { // rtp最大端口号为65535,此时rtcp端口号为65536 struct sockaddr_in addr; memset(addr.sin_zero, 0, sizeof(addr.sin_zero)); addr.sin_family = AF_INET; addr.sin_addr.s_addr = htonl(INADDR_ANY); addr.sin_port = htons(port); if (bind(*rtpSocket, (const struct sockaddr *)&addr, sizeof(addr)) < 0) { continue; } addr.sin_port = htons(port + 1); if (bind(*rtcpSocket, (const struct sockaddr *)&addr, sizeof(addr)) == 0) { *rtpPort = port; return; // 绑定rtcp端口后返回 } } TRESPASS(); }