linux下v4l2实现图片采集

#include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <stdio.h> #include <sys/ioctl.h> #include <stdlib.h> #include <sys/mman.h> #include <linux/types.h> #include <linux/videodev2.h> #include <time.h> #include <stdarg.h> #include <netinet/in.h> #include <sys/socket.h> #include <sys/errno.h> #include <arpa/inet.h> #include <string.h> #include "v4l2grab.h" #define TRUE 1 #define FALSE 0 #define FILE_VIDEO "/dev/video0" #define BMP "image_bmp.bmp" #define YUV "image_yuv.yuv" #define IMAGEWIDTH 640 #define IMAGEHEIGHT 480 static int fd; static struct v4l2_capability cap; struct v4l2_fmtdesc fmtdesc; struct v4l2_format fmt,fmtack; struct v4l2_streamparm setfps; struct v4l2_requestbuffers req; struct v4l2_buffer buf; enum v4l2_buf_type type; unsigned char frame_buffer[IMAGEWIDTH*IMAGEHEIGHT*3]; struct buffer { void * start; unsigned int length; } * buffers; int init_v4l2(void) { int i; int ret = 0; //opendev if ((fd = open(FILE_VIDEO, O_RDWR)) == -1) { printf("Error opening V4L interface\n"); return (FALSE); } //query cap if (ioctl(fd, VIDIOC_QUERYCAP, &cap) == -1) { printf("Error opening device %s: unable to query device.\n",FILE_VIDEO); return (FALSE); } else { printf("driver:\t\t%s\n",cap.driver); printf("card:\t\t%s\n",cap.card); printf("bus_info:\t%s\n",cap.bus_info); printf("version:\t%d\n",cap.version); printf("capabilities:\t%x\n",cap.capabilities); if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == V4L2_CAP_VIDEO_CAPTURE) { printf("Device %s: supports capture.\n",FILE_VIDEO); } if ((cap.capabilities & V4L2_CAP_STREAMING) == V4L2_CAP_STREAMING) { printf("Device %s: supports streaming.\n",FILE_VIDEO); } } //emu all support fmt fmtdesc.index=0; fmtdesc.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; printf("Support format:\n"); while(ioctl(fd,VIDIOC_ENUM_FMT,&fmtdesc)!=-1) { printf("\t%d.%s\n",fmtdesc.index+1,fmtdesc.description); fmtdesc.index++; } //set fmt fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV; fmt.fmt.pix.height = IMAGEHEIGHT; fmt.fmt.pix.width = IMAGEWIDTH; fmt.fmt.pix.field = V4L2_FIELD_INTERLACED; if(ioctl(fd, VIDIOC_S_FMT, &fmt) == -1) { printf("Unable to set format\n"); return FALSE; } if(ioctl(fd, VIDIOC_G_FMT, &fmt) == -1) { printf("Unable to get format\n"); return FALSE; } { printf("fmt.type:\t\t%d\n",fmt.type); printf("pix.pixelformat:\t%c%c%c%c\n",fmt.fmt.pix.pixelformat & 0xFF, (fmt.fmt.pix.pixelformat >> 8) & 0xFF,(fmt.fmt.pix.pixelformat >> 16) & 0xFF, (fmt.fmt.pix.pixelformat >> 24) & 0xFF); printf("pix.height:\t\t%d\n",fmt.fmt.pix.height); printf("pix.width:\t\t%d\n",fmt.fmt.pix.width); printf("pix.field:\t\t%d\n",fmt.fmt.pix.field); } //set fps setfps.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; setfps.parm.capture.timeperframe.numerator = 10; setfps.parm.capture.timeperframe.denominator = 10; printf("init %s \t[OK]\n",FILE_VIDEO); return TRUE; } int v4l2_grab(void) { unsigned int n_buffers; //request for 4 buffers req.count=4; req.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; req.memory=V4L2_MEMORY_MMAP; if(ioctl(fd,VIDIOC_REQBUFS,&req)==-1) { printf("request for buffers error\n"); } //mmap for buffers buffers = malloc(req.count*sizeof (*buffers)); if (!buffers) { printf ("Out of memory\n"); return(FALSE); } for (n_buffers = 0; n_buffers < req.count; n_buffers++) { buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; buf.memory = V4L2_MEMORY_MMAP; buf.index = n_buffers; //query buffers if (ioctl (fd, VIDIOC_QUERYBUF, &buf) == -1) { printf("query buffer error\n"); return(FALSE); } buffers[n_buffers].length = buf.length; //map buffers[n_buffers].start = mmap(NULL,buf.length,PROT_READ |PROT_WRITE, MAP_SHARED, fd, buf.m.offset); if (buffers[n_buffers].start == MAP_FAILED) { printf("buffer map error\n"); return(FALSE); } } //queue for (n_buffers = 0; n_buffers < req.count; n_buffers++) { buf.index = n_buffers; ioctl(fd, VIDIOC_QBUF, &buf); } type = V4L2_BUF_TYPE_VIDEO_CAPTURE; ioctl (fd, VIDIOC_STREAMON, &type); ioctl(fd, VIDIOC_DQBUF, &buf); printf("grab yuyv OK\n"); return(TRUE); } int yuyv_2_rgb888(void) { int i,j; unsigned char y1,y2,u,v; int r1,g1,b1,r2,g2,b2; char * pointer; pointer = buffers[0].start; for(i=0;i<480;i++) { for(j=0;j<320;j++) { y1 = *( pointer + (i*320+j)*4); u = *( pointer + (i*320+j)*4 + 1); y2 = *( pointer + (i*320+j)*4 + 2); v = *( pointer + (i*320+j)*4 + 3); r1 = y1 + 1.042*(v-128); g1 = y1 - 0.34414*(u-128) - 0.71414*(v-128); b1 = y1 + 1.772*(u-128); r2 = y2 + 1.042*(v-128); g2 = y2 - 0.34414*(u-128) - 0.71414*(v-128); b2 = y2 + 1.772*(u-128); if(r1>255) r1 = 255; else if(r1<0) r1 = 0; if(b1>255) b1 = 255; else if(b1<0) b1 = 0; if(g1>255) g1 = 255; else if(g1<0) g1 = 0; if(r2>255) r2 = 255; else if(r2<0) r2 = 0; if(b2>255) b2 = 255; else if(b2<0) b2 = 0; if(g2>255) g2 = 255; else if(g2<0) g2 = 0; *(frame_buffer + ((480-1-i)*320+j)*6 ) = (unsigned char)b1; *(frame_buffer + ((480-1-i)*320+j)*6 + 1) = (unsigned char)g1; *(frame_buffer + ((480-1-i)*320+j)*6 + 2) = (unsigned char)r1; *(frame_buffer + ((480-1-i)*320+j)*6 + 3) = (unsigned char)b2; *(frame_buffer + ((480-1-i)*320+j)*6 + 4) = (unsigned char)g2; *(frame_buffer + ((480-1-i)*320+j)*6 + 5) = (unsigned char)r2; } } printf("change to RGB OK \n"); } int close_v4l2(void) { if(fd != -1) { close(fd); return (TRUE); } return (FALSE); } int PtTcpSnd(int sockfd, char *buffer, int length) { int len; int totalcnt; totalcnt = 0; printf("Now Send Socket[%d]...\n",sockfd); while(totalcnt < length) { len = write(sockfd, buffer + totalcnt, length - totalcnt); printf("Send Socket len[%d]\n",len); if (len < 0) { if (errno == EINTR) { len = 0; break; } else return(-1); } else if (len == 0) break; totalcnt = totalcnt + len; } return(totalcnt); } int sendpitctue(void)//发送图片 { int cfd; struct sockaddr_in s_add; unsigned short portnum=12306; printf("Hello,welcome to client !\r\n"); cfd = socket(AF_INET, SOCK_STREAM, 0); if(-1 == cfd) { printf("socket fail ! \r\n"); return -1; } printf("socket ok !\r\n"); bzero(&s_add,sizeof(struct sockaddr_in)); s_add.sin_family=AF_INET; s_add.sin_addr.s_addr= inet_addr("192.168.1.5"); s_add.sin_port=htons(portnum); if(-1 == connect(cfd,(struct sockaddr *)(&s_add), sizeof(struct sockaddr))) { printf("connect fail !\r\n"); return -1; } printf("connect ok !\r\n"); FILE *fp = fopen(BMP, "rb"); if (fp == NULL) { fprintf(stderr, "cannot open image file\n"); exit(1); } fseek(fp, 0, SEEK_END); if (ferror(fp)) { fprintf(stderr, "fseek() failed\n"); int r = fclose(fp); if (r == EOF) { fprintf(stderr, "cannot close file handler\n"); } exit(1); } int flen = ftell(fp); if (flen == -1) { perror("error occurred"); int r = fclose(fp); if (r == EOF) { fprintf(stderr, "cannot close file handler\n"); } exit(1); } fseek(fp, 0, SEEK_SET); if (ferror(fp)) { fprintf(stderr, "fseek() failed\n"); int r = fclose(fp); if (r == EOF) { fprintf(stderr, "cannot close file handler\n"); } exit(1)