udp socket: 简单的数据包与视频流传输

简单的包传输

客户端向服务端发送数据包，服务端打印出来。
我们来传送一首诗吧，柳永的《雨霖铃》
服务端：

#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <string.h>
#include <netinet/in.h>
#include <unistd.h>
#include <stdlib.h>
#include <arpa/inet.h>
#define PORT 24000

int main(){ 
    int s=socket(AF_INET,SOCK_DGRAM,0);
    if(s==-1){
        perror("create socket error: ");
        exit(1);
    }
    struct sockaddr_in serv,client;
    bzero(&serv,sizeof(serv));
    serv.sin_family=AF_INET;   
    serv.sin_addr.s_addr=inet_addr("10.21.100.153");// targe IP  
    serv.sin_port=htons(PORT);  
    if(bind(s,(struct sockaddr*)&serv,sizeof(serv))==-1){
        perror("bind error: ");
        exit(1);
    }
    int count = 0;
    char *buff = (char *)malloc(100);
    while(count < 10){
        int addr_len = sizeof(client);
        memset(buff,0,100);
        int ret = recvfrom(s,buff,100,0,(struct sockaddr *)&client,&addr_len); 
        if(ret == -1){
            perror("recvfrom error: ");
            exit(1);
        }
        else {
            count++;
            printf("%s\n",buff);
        }
    }
    close(s);
    if(buff) free(buff);
    return 0;
}

客户端：

#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <string.h>
#include <netinet/in.h>
#include <unistd.h>
#include <stdlib.h>
#include <arpa/inet.h>
#define PORT 24000

int main(){ 
        int s=socket(AF_INET,SOCK_DGRAM,0);
        if(s==-1){
             perror("create socket error: ");
             exit(1);
        }
        struct sockaddr_in serv;
        bzero(&serv,sizeof(serv));
        serv.sin_family=AF_INET;   
        serv.sin_addr.s_addr = inet_addr("10.21.100.153");    // targe IP 
        serv.sin_port=htons(PORT);
        char *buff = NULL;
        int i = 0;
        char str[10][80]={
  
  "雨霖铃","","寒蝉凄切，对长亭晚，骤雨初歇。","都门帐饮无绪，留恋处，兰舟摧发。",
            "执手相看泪眼，竟无语凝噎。","念去去千里烟波，暮霭沈沈楚天阔。","多情自古伤离别，更那堪冷落清秋节。",
        "今宵酒醒何处，杨柳岸、晓风残月。","此去经年，应是良辰好景虚设。","便纵有千种风情，更与何人说。"};
        while(i < 10){
             buff = str[i];
             sendto(s,buff,strlen(buff),0,