by default live library includes winsock.h through windows.h instead of winsock2.h, but requires Winsock 2 in initializeWinsockIfNecessary(...) function.
IP_ADD_MEMBERSHIP value for Winsock1 is 5, and for Winsock 2 is 12.
Therefore socketJoinGroup(...) function is trying to call setsockopt(IP_ADD_MEMBERSHIP) from Winsock 2 with optname from Winsock 1.
There is the confusion between Winsock versions.
live555的 组播的code如下 :
testAddr.s_addr = our_inet_addr("228.67.43.91"); // arbitrary
Port testPort(15947); // ditto
sock = setupDatagramSocket(env, testPort);
if (sock < 0) break;
if (!socketJoinGroup(env, sock, testAddr.s_addr))
{
env<<"Failed to socket Join Group\n";
break;
}
结果：
if (setsockopt(socket, IPPROTO_IP, IP_ADD_MEMBERSHIP,
(const char*)&imr, sizeof (struct ip_mreq)) < 0) {
一直失败：错误提示为： 10042：
修改为： if (setsockopt(socket, IPPROTO_IP, 12,
(const char*)&imr, sizeof (struct ip_mreq)) < 0) {
因为不同的socket版本，定义IP_ADD_MEMBERSHIP 的值不同：
in socket ver1.0中：
＃define IP_ADD_MEMBERSHIP 5
in socket ver2.0中：
＃define IP_ADD_MEMBERSHIP 12