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
- }
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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。
(1)函数声明:创建一对相邻端口的UDP数据报套接字。rtp套接字是偶数端口,rtcp套接字端口比rtp端口号大一个号。
- // 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 &#61; start; port < 65536; port &#43;&#61; 2) { // rtp最大端口号为65535&#xff0c;此时rtcp端口号为65536
- struct sockaddr_in addr;
- memset(addr.sin_zero, 0, sizeof(addr.sin_zero));
- addr.sin_family &#61; AF_INET;
- addr.sin_addr.s_addr &#61; htonl(INADDR_ANY);
- addr.sin_port &#61; htons(port);
-
- if (bind(*rtpSocket,
- (const struct sockaddr *)&addr, sizeof(addr)) < 0) {
- continue;
- }
-
- addr.sin_port &#61; htons(port &#43; 1);
-
- if (bind(*rtcpSocket,
- (const struct sockaddr *)&addr, sizeof(addr)) &#61;&#61; 0) {
- *rtpPort &#61; port;
- return; // 绑定rtcp端口后返回
- }
- }
-
- TRESPASS();
- }