海康IP-camera在linux進行變焦

發現還海康相機在linux上面焦距是固定的，不能像在windows那樣直接在web端進行調焦，因此只能通過代碼來給它加個控制。

/*************************************************************************
	> File Name: 485.c
	> Author: fqlovetb
	> Created Time: Thurs  September 2019 14:45:21 
 ************************************************************************/
 
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <arpa/inet.h>
#include <netinet/in.h>

//5004 is to port1 
//IP address 192.168.1.125
const int port = 5004;
const char* ip = "192.168.1.125"; 
 
int main()
{
	  //create socket 
	  int clt_sock = socket(AF_INET, SOCK_STREAM, 0); 
	  if(clt_sock < 0)
	  {

		  perror("socket");
		  return 1;
	  }
 
	  //name is socket 
	  struct sockaddr_in addr; 
	  addr.sin_family = AF_INET; 
	  addr.sin_port = htons(port); 
	  //IPv4 address
	  addr.sin_addr.s_addr = inet_addr(ip); 

          //struct sockaddr_in peer;
	  socklen_t addr_len = sizeof(addr);
	  int connect_fd = connect(clt_sock, (struct sockaddr*)&addr, addr_len);
	  if(connect_fd < 0)
	  {
		  perror("connect");
		  return 2;
	  }
	  
 	char red_buf[64];

	char buf[8];
	  while(1)
	  {
		  //memset(buf, '\0', sizeof(buf));
		  fflush(stdout);
			buf[0] = 0xFF;
			buf[1] = 0x01;
			buf[2] = 0x00;
			buf[3] = 0x20;
			buf[4] = 0x00;
			buf[5] = 0x00;
			buf[6] = 0x21;
		printf("**Send successfully**\n");
		  //{0xFF,0x01,0x00,0x20,0x00,0x00,0x21,}變倍短
		  //{0xFF,0x01,0x00,0x40,0x00,0x00,0x41,}變倍長
		sleep(30);
          write(clt_sock, buf, strlen(buf));
	   }
	  close(clt_sock);
	  return 0;
}