udpclient1.c

LINUX下编写的视频采集客户端接收程序 用udp协议实现的

#include <stdio.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <netdb.h>

#define PORT 1234
#define MAX  13000
int main(int argc,char *argv[])
{
int fd, numbytes,i,jpegsize;
unsigned char buf[MAX];
struct sockaddr_in server,reply;
FILE *fp;
struct hostent *he;
if(argc!=3){
printf("usage:%s<ip address>\n",argv[0]);
exit(1);
}
if((he=gethostbyname(argv[1]))==NULL){
printf("get error");
exit(1);
}

if((fd=socket(AF_INET,SOCK_DGRAM,0))==-1){
printf("creat socket error");
exit(1);
}

bzero(&server,sizeof(server));
server.sin_family=AF_INET;
server.sin_port=htons(PORT);
server.sin_addr=*((struct in_addr *)he->h_addr);
sendto(fd,argv[2],strlen(argv[2]),0,(struct sockaddr *)&server,sizeof(struct sockaddr));
while(1){
int len;
static int l=0;
//static int k=0;
//numbytes=recvfrom(fd,buf,MAX,0,(struct sockaddr *)&reply,&len);
//printf("server message: %d ",numbytes);
if((numbytes=recvfrom(fd,buf,MAX,0,(struct sockaddr *)&reply,&len))==-1){
printf("recv eoor");
exit(1);
}
else  l++;
printf("the frame number is %d\n",l);
//printf("len is %d",len);
//if(len!=sizeof(struct sockaddr)){
//printf("re ma from other server");
//continue;}

for ( i=7000; i< MAX; i++) {
 	if ((buf[i] == 0xFF) && (buf[i+1] == 0xD9)){
 	jpegsize=i+2;
 	break;}
}
if(l==1150)
{fp = fopen("/usr/4.jpg", "w");
//if (fp == NULL) {
//fprintf(stderr, "file creation failed");
//exit(1);}
fwrite(buf, jpegsize, 1, fp);
fclose(fp);}
//if(getchar()=='q')break;
}
close(fd);
}