组播测试小程序

#include <winsock2.h>
#include <stdio.h>

#define MCASTADDR	"234.5.6.101"	 //本例使用的多播组地址。
#define MCASTPORT	7000			 //绑定的本地端口号。
#define BUFSIZE		5000			 //接收数据缓冲大小。

int main( int argc,char ** argv)
{
	WSADATA wsd;

	struct sockaddr_in local;	//本地
	struct sockaddr_in remote;	//组播源
	struct sockaddr_in from;;	//实际数据来源

	SOCKET sock;
	SOCKET sockM;

	char recvbuf[BUFSIZE];

	int len = sizeof(struct sockaddr_in);
	int ret;
	
	//初始化WinSock2.2
	if(WSAStartup(MAKEWORD(2,2),&wsd) != 0 )
	{
		printf("WSAStartup() failed\n");
		
		return -1;
	}
	
	if((sock = WSASocket(AF_INET, SOCK_DGRAM, 0, NULL, 0,
				WSA_FLAG_MULTIPOINT_C_LEAF | WSA_FLAG_MULTIPOINT_D_LEAF |
				WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)
	{
		printf("socket failed with:%d\n",WSAGetLastError());
		
		WSACleanup();
		
		return -1;	
	}
	
	//将sock绑定到本机某端口上。
	local.sin_family = AF_INET;
	local.sin_port = htons(MCASTPORT);
	local.sin_addr.s_addr = INADDR_ANY;
	
	if(bind(sock, (struct sockaddr*)&local, sizeof(local)) == SOCKET_ERROR )
	{
		printf( "bind failed with:%d \n",WSAGetLastError());
		
		closesocket(sock);
		WSACleanup();
	
		return -1;
	}
	
	//加入多播组
	remote.sin_family = AF_INET;
	remote.sin_port = htons(MCASTPORT);
	remote.sin_addr.s_addr = inet_addr(MCASTADDR );
	
	if((sockM = WSAJoinLeaf(sock,(SOCKADDR*)&remote,sizeof(remote),NULL,NULL,NULL,NULL, JL_BOTH)) == INVALID_SOCKET)
	{
		printf("WSAJoinLeaf() failed:%d\n",WSAGetLastError());

		closesocket(sock);

		WSACleanup();

		return -1;
	}
	
	FILE * pFile;
	
	if ((pFile = fopen(".\\out.264", "wb")) == NULL)
	{
		printf("Cannot open file!\n");
	}

	bool bIsStart = false;

	while(1)
	{
		ret = recvfrom(sock,recvbuf,BUFSIZE,0,(struct sockaddr*)&from, &len);
//		ret = recvfrom(sock, recvbuf, BUFSIZE, 0, NULL, NULL);
		
		if(ret == SOCKET_ERROR)
		{
			printf("recvfrom failed with:%d\n", WSAGetLastError());

			closesocket(sockM);
			closesocket(sock);
			WSACleanup();
			
			return -1;
		}
		
		if (bIsStart == false)
		{
			if ((recvbuf[26] == 0x00) && (recvbuf[27] == 0x01) && (recvbuf[28] == 0x67))
			{
				bIsStart = true;
			}
			else
			{
				continue;
			}
		}
		

		fwrite(recvbuf + 24, sizeof(char), ret - 24, pFile);		
	}
	
	closesocket(sockM);
	closesocket(sock);
	WSACleanup();
	
	return 0;
}

注意：附加依赖项中要添加ws2_32.lib