Example live receiver (#496)

CMakeLists.txt

@@ -919,6 +919,9 @@ if (ENABLE_EXAMPLES)
 	srt_add_example(recvfile.cpp apps/logsupport.cpp)
 	srt_make_application(recvfile)
 
+	srt_add_example(recvlive.cpp apps/logsupport.cpp)
+	srt_make_application(recvlive)
+
 	srt_add_example(test-c-client.c)
 	srt_make_application(test-c-client)
 

examples/recvlive.cpp

@@ -0,0 +1,199 @@
+#ifndef WIN32
+   #include <cstdlib>
+   #include <netdb.h>
+#else
+   #include <winsock2.h>
+   #include <ws2tcpip.h>
+#endif
+#include <fstream>
+#include <iostream>
+#include <string>
+#include <cstring>
+#include <srt.h>
+#include <assert.h>             // assert
+
+using namespace std;
+
+int main(int argc, char* argv[])
+{
+   // usage: recvlive [server_port]
+   if ((2 < argc) || ((2 == argc) && (0 == atoi(argv[1]))))
+   {
+      cout << "usage: recvlive [server_port]" << endl;
+      return 0;
+   }
+
+   // use this function to initialize the UDT library
+   srt_startup();
+
+   srt_setloglevel(logging::LogLevel::debug);
+
+   addrinfo hints;
+   addrinfo* res;
+
+   memset(&hints, 0, sizeof(struct addrinfo));
+   hints.ai_flags = AI_PASSIVE;
+   hints.ai_family = AF_INET;
+   hints.ai_socktype = SOCK_DGRAM;
+
+   string service("9000");
+   if (2 == argc)
+      service = argv[1];
+
+   if (0 != getaddrinfo(NULL, service.c_str(), &hints, &res))
+   {
+      cout << "illegal port number or port is busy.\n" << endl;
+      return 0;
+   }
+
+   SRTSOCKET sfd = srt_socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+   if (SRT_INVALID_SOCK == sfd)
+   {
+      cout << "srt_socket: " << srt_getlasterror_str() << endl;
+      return 0;
+   }
+
+   // SRT requires that third argument is always SOCK_DGRAM. The Stream API is set by an option,
+   // although there's also lots of other options to be set, for which there's a convenience option,
+   // SRTO_TRANSTYPE.
+   // SRT_TRANSTYPE tt = SRTT_LIVE;
+   // if (SRT_ERROR == srt_setsockopt(sfd, 0, SRTO_TRANSTYPE, &tt, sizeof tt))
+   // {
+   //    cout << "srt_setsockopt: " << srt_getlasterror_str() << endl;
+   //    return 0;
+   // }
+
+   bool no = false;
+   if (SRT_ERROR == srt_setsockopt(sfd, 0, SRTO_RCVSYN, &no, sizeof no))
+   {
+      cout << "srt_setsockopt: " << srt_getlasterror_str() << endl;
+      return 0;
+   }
+
+   // Windows UDP issue
+   // For better performance, modify HKLM\System\CurrentControlSet\Services\Afd\Parameters\FastSendDatagramThreshold
+#ifdef WIN32
+   int mss = 1052;
+   srt_setsockopt(sfd, 0, SRTO_MSS, &mss, sizeof(int));
+#endif
+
+   // int64_t maxbw = 5000000;
+   // srt_setsockopt(sfd, 0, SRTO_MAXBW, &maxbw, sizeof maxbw);
+
+   if (SRT_ERROR == srt_bind(sfd, res->ai_addr, res->ai_addrlen))
+   {
+      cout << "srt_bind: " << srt_getlasterror_str() << endl;
+      return 0;
+   }
+
+   freeaddrinfo(res);
+
+   cout << "server is ready at port: " << service << endl;
+
+   if (SRT_ERROR == srt_listen(sfd, 10))
+   {
+      cout << "srt_listen: " << srt_getlasterror_str() << endl;
+      return 0;
+   }
+
+   int epid = srt_epoll_create();
+   if (epid < 0)
+   {
+      cout << "srt_epoll_create: " << srt_getlasterror_str() << endl;
+      return 0;
+   }
+
+   int events = SRT_EPOLL_IN | SRT_EPOLL_ERR;
+   if (SRT_ERROR == srt_epoll_add_usock(epid, sfd, &events))
+   {
+      cout << "srt_epoll_add_usock: " << srt_getlasterror_str() << endl;
+      return 0;
+   }
+
+   constexpr int srtrfdslenmax = 100;
+   SRTSOCKET srtrfds[srtrfdslenmax];
+   char data[1500];
+
+   // the event loop
+   while (true)
+   {
+      int srtrfdslen = srtrfdslenmax;
+      int n = srt_epoll_wait(epid, &srtrfds[0], &srtrfdslen, 0, 0, 100, 0, 0, 0, 0);
+      assert(n <= srtrfdslen);
+      for (int i = 0; i < n; i++)
+      {
+         SRTSOCKET s = srtrfds[i];
+         SRT_SOCKSTATUS status = srt_getsockstate(s);
+         if ((status == SRTS_BROKEN) ||
+             (status == SRTS_NONEXIST) ||
+             (status == SRTS_CLOSED))
+         {
+            cout << "source disconnected. status=" << status << endl;
+            srt_close(s);
+            continue;
+         }
+         else if (s == sfd)
+         {
+            assert(status == SRTS_LISTENING);
+
+            SRTSOCKET fhandle;
+            sockaddr_storage clientaddr;
+            int addrlen = sizeof(clientaddr);
+
+            fhandle = srt_accept(sfd, (sockaddr*)&clientaddr, &addrlen);
+            if (SRT_INVALID_SOCK == fhandle)
+            {
+               cout << "srt_accept: " << srt_getlasterror_str() << endl;
+               return 0;
+            }
+
+            char clienthost[NI_MAXHOST];
+            char clientservice[NI_MAXSERV];
+            getnameinfo((sockaddr *)&clientaddr, addrlen,
+                        clienthost, sizeof(clienthost),
+                        clientservice, sizeof(clientservice), NI_NUMERICHOST|NI_NUMERICSERV);
+            cout << "new connection: " << clienthost << ":" << clientservice << endl;
+
+            int events = SRT_EPOLL_IN | SRT_EPOLL_ERR;
+            if (SRT_ERROR == srt_epoll_add_usock(epid, fhandle, &events))
+            {
+               cout << "srt_epoll_add_usock: " << srt_getlasterror_str() << endl;
+               return 0;
+            }
+         }
+         else
+         {
+            while (true)
+            {
+               int ret = srt_recvmsg(s, data, sizeof(data));
+               if (SRT_ERROR == ret)
+               {
+                  // EAGAIN for SRT READING
+                  if (SRT_EASYNCRCV != srt_getlasterror(NULL))
+                  {
+                     cout << "srt_recvmsg: " << srt_getlasterror_str() << endl;
+                     return 0;
+                  }
+                  break;
+               }
+               // cout << ret << " bytes received" << endl;
+            }
+         }
+      }
+   }
+
+   srt_close(sfd);
+
+   srt_epoll_release(epid);
+
+   // use this function to release the UDT library
+   srt_cleanup();
+
+   return 0;
+}
+
+// Local Variables:
+// c-file-style: "ellemtel"
+// c-basic-offset: 3
+// compile-command: "g++ -Wall -O2 -std=c++11 -I.. -I../srtcore -o recvlive recvlive.cpp -L.. -lsrt -lpthread -L/usr/local/opt/openssl/lib -lssl -lcrypto"
+// End: