Live555 many such functions return unsigned
unsigned RTSPServer::registerStream(ServerMediaSession* serverMediaSession,
char const* remoteClientNameOrAddress, portNumBits remoteClientPortNum,
responseHandlerForREGISTER* responseHandler,
char const* username, char const* password,
Boolean receiveOurStreamViaTCP, char const* proxyURLSuffix)
unsigned is actually unsigned int, which means unsigned integer, you can omit int, which is equivalent to unsigned int