video input capture一张图片 demo程序

#include 
#include 
#include 
#include 
#include   
#include   
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#define CLEAR(x) memset (&(x), 0, sizeof (x))

#define VIDEO_WIDTH 1280
#define VIDEO_HEIGHT 720


int convert_yuv_to_rgb_pixel(int y, int u, int v)
{
	unsigned int pixel32 = 0;
	unsigned char *pixel = (unsigned char *)&pixel32;
	int r, g, b;
	r = y + (1.370705 * (v-128));
	g = y - (0.698001 * (v-128)) - (0.337633 * (u-128));
	b = y + (1.732446 * (u-128));
	if(r > 255) r = 255;
	if(g > 255) g = 255;
	if(b > 255) b = 255;
	if(r < 0) r = 0;
	if(g < 0) g = 0;
	if(b < 0) b = 0;
	pixel[0] = r ;
	pixel[1] = g ;
	pixel[2] = b ;
	return pixel32;
}

int convert_yuv_to_rgb_buffer(unsigned char *yuv, unsigned char *rgb, unsigned int width, unsigned int height)
{
	unsigned int in, out = 0;
	unsigned int pixel_16;
	unsigned char pixel_24[3];
	unsigned int pixel32;
	int y0, u, y1, v;

	for(in = 0; in < width * height * 2; in += 4)
	{
		pixel_16 =
		yuv[in + 3] << 24 |
		yuv[in + 2] << 16 |
		yuv[in + 1] <<  8 |
		yuv[in + 0];
		y0 = (pixel_16 & 0x000000ff);
		u  = (pixel_16 & 0x0000ff00) >>  8;
		y1 = (pixel_16 & 0x00ff0000) >> 16;
		v  = (pixel_16 & 0xff000000) >> 24;
		pixel32 = convert_yuv_to_rgb_pixel(y0, u, v);
		pixel_24[0] = (pixel32 & 0x000000ff);
		pixel_24[1] = (pixel32 & 0x0000ff00) >> 8;
		pixel_24[2] = (pixel32 & 0x00ff0000) >> 16;
		rgb[out++] = pixel_24[0];
		rgb[out++] = pixel_24[1];
		rgb[out++] = pixel_24[2];
		pixel32 = convert_yuv_to_rgb_pixel(y1, u, v);
		pixel_24[0] = (pixel32 & 0x000000ff);
		pixel_24[1] = (pixel32 & 0x0000ff00) >> 8;
		pixel_24[2] = (pixel32 & 0x00ff0000) >> 16;
		rgb[out++] = pixel_24[0];
		rgb[out++] = pixel_24[1];
		rgb[out++] = pixel_24[2];
	}
	return 0;
}
 
struct buffer {
    void * start;
    size_t length;
};
 
static char * dev_name = NULL;
static int fd = -1;
struct buffer * buffers = NULL;
static unsigned int n_buffers = 0;
static int time_in_sec_capture=5;
static int fbfd = -1;
static struct fb_var_screeninfo vinfo;
static struct fb_fix_screeninfo finfo;
static char *fbp=NULL;
static long screensize=0;
#if 0
//保存为图片test.jpg
void GenJpgFile(buffer *buffers){
	FILE *fp = NULL;
	fp = fopen("/vin_save.yuv", "w");
	if(fp != NULL){
		fwrite(buffers->start, 1,buffers->length, fp);
			sync();
			fclose(fp);
	}
}
#endif
 
static void errno_exit (const char * s)
{
    fprintf (stderr, "%s error %d, %s\n",s, errno, strerror (errno));
    exit (EXIT_FAILURE);
}
 
static int xioctl (int fd,int request,void * arg)
{
    int r;
    do r = ioctl (fd, request, arg);
    while (-1 == r && EINTR == errno);
    return r;
}
 
inline int clip(int value, int min, int max) {
    return (value > max ? max : value < min ? min : value);
  }
 
static void process_image (const void * p){
 
    
    //ConvertYUVToRGB32
// 1;
    unsigned char* in=(char*)p;
    int width=VIDEO_WIDTH;
    int height=VIDEO_HEIGHT;
    int istride=1280;
    int x,y,j;
    int y0,u,y1,v,r,g,b;
    long location=0;
 
    for ( y = 100; y < height + 100; ++y) {
        for (j = 0, x=100; j < width * 2 ; j += 4,x +=2) {
          location = (x+vinfo.xoffset) * (vinfo.bits_per_pixel/8) + (y+vinfo.yoffset) * finfo.line_length;
            
          y0 = in[j];
          u = in[j + 1] - 128;                
          y1 = in[j + 2];        
          v = in[j + 3] - 128;        
 
          r = (298 * y0 + 409 * v + 128) >> 8;
          g = (298 * y0 - 100 * u - 208 * v + 128) >> 8;
          b = (298 * y0 + 516 * u + 128) >> 8;
        
          fbp[ location + 0] = clip(b, 0, 255);
          fbp[ location + 1] = clip(g, 0, 255);
          fbp[ location + 2] = clip(r, 0, 255);    
          fbp[ location + 3] = 255;    
 
          r = (298 * y1 + 409 * v + 128) >> 8;
          g = (298 * y1 - 100 * u - 208 * v + 128) >> 8;
          b = (298 * y1 + 516 * u + 128) >> 8;
 
          fbp[ location + 4] = clip(b, 0, 255);
          fbp[ location + 5] = clip(g, 0, 255);
          fbp[ location + 6] = clip(r, 0, 255);    
          fbp[ location + 7] = 255;    
          }
        in +=istride;
      }
}
 
static int read_frame (void)
{
    struct v4l2_buffer buf;
    unsigned int i,j,line_y_pos24bit,line_y_pos32bit;
	char * buf_24bit = NULL;
	char * buf_32bit = NULL;

	line_y_pos24bit = 0;
	line_y_pos32bit = 0;

	buf_24bit = (char*)calloc(1, VIDEO_WIDTH*VIDEO_HEIGHT*3);
    if(buf_24bit == NULL){
        printf("load > malloc buf_24bit bmp out of memory!\n");
        return -1;
    }

	buf_32bit = (char*)calloc(1, VIDEO_WIDTH*VIDEO_HEIGHT*4);
    if(buf_32bit == NULL){
        printf("load > malloc buf_32bit bmp out of memory!\n");
        return -1;
    }
 
    CLEAR (buf);
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    buf.memory = V4L2_MEMORY_MMAP;
 
    if (-1 == xioctl (fd, VIDIOC_DQBUF, &buf)) {
        switch (errno) {
        case EAGAIN:
        return 0;
        case EIO:    
 
        
 
        default:
            errno_exit ("VIDIOC_DQBUF");
        }
    }
 
    assert (buf.index < n_buffers);
 	printf("buf.index = %d, buf.field = %d\n", buf.index,buf.field);
    //assert (buf.field ==V4L2_FIELD_NONE);
   	FILE *fp33 = NULL;
	fp33 = fopen("./vin.yuv", "w");
	if(fp33 != NULL){
		fwrite(buffers[buf.index].start, 1,buffers[buf.index].length, fp33);
			sync();
			fclose(fp33);
			printf("write file[vin.yuv] OK.\n");
	}
//    process_image (buffers[buf.index].start);
	convert_yuv_to_rgb_buffer(buffers[buf.index].start,buf_24bit,VIDEO_WIDTH,VIDEO_HEIGHT);
	for( j = 0; j < VIDEO_HEIGHT; j++ ){
		line_y_pos24bit = j*VIDEO_WIDTH*3;
		line_y_pos32bit = j*VIDEO_WIDTH*4;
		for( i = 0; i < VIDEO_WIDTH; i++ ){
			buf_32bit[i*4+0+line_y_pos32bit] = buf_24bit[i*3+0+line_y_pos24bit];
			buf_32bit[i*4+1+line_y_pos32bit] = buf_24bit[i*3+1+line_y_pos24bit];
			buf_32bit[i*4+2+line_y_pos32bit] = buf_24bit[i*3+2+line_y_pos24bit];
			buf_32bit[i*4+3+line_y_pos32bit] = 0xff;
		}
	}

	memcpy(fbp,buf_32bit,VIDEO_WIDTH*VIDEO_HEIGHT*4);

    if (-1 == xioctl (fd, VIDIOC_QBUF, &buf))
        errno_exit ("VIDIOC_QBUF");


	free(buf_24bit);
    free(buf_32bit);
    return 0;
}
 
static void run (void)
{
    unsigned int count;
    int frames;
    frames = 30 * time_in_sec_capture;
 
    while (frames-- > 0) {
        for (;;) {
            fd_set fds;
            struct timeval tv;
            int r;
            FD_ZERO (&fds);
            FD_SET (fd, &fds);
 
            
            tv.tv_sec = 2;
            tv.tv_usec = 0;
 
            r = select (fd + 1, &fds, NULL, NULL, &tv);
 
            if (-1 == r) {
                if (EINTR == errno)
                    continue;
                errno_exit ("select");
            }
 
            if (0 == r) {
                fprintf (stderr, "select timeout\n");
                exit (EXIT_FAILURE);
            }
 
            if (read_frame ())
                break;
            
            }
    }
}
 
static void stop_capturing (void)
{
    enum v4l2_buf_type type;
 
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    if (-1 == xioctl (fd, VIDIOC_STREAMOFF, &type))
        errno_exit ("VIDIOC_STREAMOFF");
}
 
static void start_capturing (void)
{
	unsigned int i;
	enum v4l2_buf_type type;

	for (i = 0; i < n_buffers; ++i) {
		struct v4l2_buffer buf;
		CLEAR (buf);

		buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
		buf.memory = V4L2_MEMORY_MMAP;
		buf.index = i;

		if (-1 == xioctl (fd, VIDIOC_QBUF, &buf))
			errno_exit ("VIDIOC_QBUF");
	}

	type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

	if (-1 == xioctl (fd, VIDIOC_STREAMON, &type))
		errno_exit ("VIDIOC_STREAMON");
    
}
 
static void uninit_device (void)
{
    unsigned int i;
 
    for (i = 0; i < n_buffers; ++i)
        if (-1 == munmap (buffers[i].start, buffers[i].length))
            errno_exit ("munmap");
    
    if (-1 == munmap(fbp, screensize)) {
          printf(" Error: framebuffer device munmap() failed.\n");
          exit (EXIT_FAILURE) ;
        }    
    free (buffers);
}
 
 
static void init_mmap (void)
{
    struct v4l2_requestbuffers req;
 
    //mmap framebuffer
    fbp = (char *)mmap(NULL,screensize,PROT_READ | PROT_WRITE,MAP_SHARED ,fbfd, 0);
    if ((int)fbp == -1) {
        printf("Error: failed to map framebuffer device to memory./n");
        exit (EXIT_FAILURE) ;
    }
    memset(fbp, 0, screensize);
    CLEAR (req);
 
    req.count = 4;
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    req.memory = V4L2_MEMORY_MMAP;
 
    if (-1 == xioctl (fd, VIDIOC_REQBUFS, &req)) {
        if (EINVAL == errno) {
            fprintf (stderr, "%s does not support memory mapping/n", dev_name);
            exit (EXIT_FAILURE);
        } else {
            errno_exit ("VIDIOC_REQBUFS");
        }
    }
 
    if (req.count < 4) {    //if (req.count < 2)
        fprintf (stderr, "Insufficient buffer memory on %s\n",dev_name);
        exit (EXIT_FAILURE);
    }
 
    buffers = calloc (req.count, sizeof (*buffers));
 
    if (!buffers) {
        fprintf (stderr, "Out of memory\n");
        exit (EXIT_FAILURE);
    }
 
    for (n_buffers = 0; n_buffers < req.count; ++n_buffers) {
        struct v4l2_buffer buf;
 
        CLEAR (buf);
 
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        buf.memory = V4L2_MEMORY_MMAP;
        buf.index = n_buffers;
 
        if (-1 == xioctl (fd, VIDIOC_QUERYBUF, &buf))
            errno_exit ("VIDIOC_QUERYBUF");
 
        buffers[n_buffers].length = buf.length;
        buffers[n_buffers].start =mmap (NULL,buf.length,PROT_READ | PROT_WRITE ,MAP_SHARED,fd, buf.m.offset);
 
        if (MAP_FAILED == buffers[n_buffers].start)
            errno_exit ("mmap");
    }
 
}
 
 
 
static void init_device (void)
{
    struct v4l2_capability cap;
    struct v4l2_cropcap cropcap;
    struct v4l2_crop crop;
    struct v4l2_format fmt;
    unsigned int min;
 
 
    // Get fixed screen information
      if (-1==xioctl(fbfd, FBIOGET_FSCREENINFO, &finfo)) {
            printf("Error reading fixed information.\n");
            exit (EXIT_FAILURE);
        }
 
        // Get variable screen information
    if (-1==xioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo)) {
            printf("Error reading variable information.\n");
            exit (EXIT_FAILURE);
      }
    screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
 
 
    if (-1 == xioctl (fd, VIDIOC_QUERYCAP,(void *)&cap)) {
        if (EINVAL == errno) {
            fprintf (stderr, "%s is no V4L2 device\n",dev_name);
            exit (EXIT_FAILURE);
        } else {
            errno_exit ("VIDIOC_QUERYCAP");
        }
    }
 	printf("info: ==========cap.capabilities = 0x%08x.\n",cap.capabilities);
	#if 1
    if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
        fprintf (stderr, "%s is no video capture device\n",dev_name);
        exit (EXIT_FAILURE);
    }
	printf("info: %s is a video capture device.\n",dev_name);
	#else
	if( !(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE_MPLANE) ){
		fprintf (stderr, "%s is not a V4L2_CAP_VIDEO_CAPTURE_MPLANE device \n",dev_name);
        	exit (EXIT_FAILURE);
	}
	printf("[%s] is a  V4L2_CAP_VIDEO_CAPTURE_MPLANE device.\n",dev_name);
	
	CLEAR (fmt);
 
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
 printf("------------VIDIOC_G_FMT start----------------------\n");
    if (-1 == xioctl (fd, VIDIOC_G_FMT, &fmt))
        errno_exit ("VIDIOC_G_FMT");

	printf(" fmt.fmt.pix_mp.width = 0x%08x.\n ",fmt.fmt.pix_mp.width);
	printf(" fmt.fmt.pix_mp.height = 0x%08x.\n ",fmt.fmt.pix_mp.height);
	printf(" fmt.fmt.pix_mp.pixelformat = 0x%08x.\n ",fmt.fmt.pix_mp.pixelformat);
	printf("------------VIDIOC_G_FMT end----------------------\n");
 	return;
	#endif
/***************************************************/
	
    if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
        fprintf (stderr, "%s does not support streaming i/o\n",dev_name);
        exit (EXIT_FAILURE);
    }
 	printf("info: %s support streaming i/o.\n",dev_name);
    
 
    CLEAR (cropcap);
 
    cropcap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 
    if (0 == xioctl (fd, VIDIOC_CROPCAP, &cropcap)) {
        crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        crop.c = cropcap.defrect;
 
        if (-1 == xioctl (fd, VIDIOC_S_CROP, &crop)) {
            switch (errno) {
	            case EINVAL:    
				printf("VIDIOC_S_CROP error!\n");
	           		break;
	            default:
	            	break;
            }
        }
    }else {   
    	printf("VIDIOC_S_CROP error 1!\n");
    }
 
    CLEAR (fmt);
 
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    fmt.fmt.pix.width = VIDEO_WIDTH;  
    fmt.fmt.pix.height = VIDEO_HEIGHT;
    fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
//    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
	fmt.fmt.pix.field = V4L2_FIELD_NONE;
 
    if (-1 == xioctl (fd, VIDIOC_S_FMT, &fmt))
        errno_exit ("VIDIOC_S_FMT");

 	printf("-->VIDIOC_S_FMT OK.\n");
    init_mmap ();
 
}
 
static void close_device (void)
{
    if (-1 == close (fd))
   		errno_exit ("close");
//    fd = -1;
    close(fbfd);
	printf("info:close device OK.\n");
}
 
static void open_device (void)
{
	struct stat st;  

	if (-1 == stat (dev_name, &st)) {
		fprintf (stderr, "Cannot identify '%s': %d, %s\n",dev_name, errno, strerror (errno));
		exit (EXIT_FAILURE);
	}

	if (!S_ISCHR (st.st_mode)) {
		fprintf (stderr, "%s is no device\n", dev_name);
		exit (EXIT_FAILURE);
	}

	//open framebuffer
	fbfd = open("/dev/fb0", O_RDWR);
	if (fbfd==-1) {
		printf("Error: cannot open framebuffer device.\n");
		exit (EXIT_FAILURE);
	}
	printf("info: opened framebuffer /dev/fb0 device.\n");

	//open camera
	fd = open (dev_name, O_RDWR| O_NONBLOCK, 0);

	if (-1 == fd) {
		fprintf (stderr, "Cannot open '%s': %d, %s\n",dev_name, errno, strerror (errno));
		exit (EXIT_FAILURE);
	}
	printf("info: opened camera device [%s].\n",dev_name);
	
}
 
static void usage (FILE * fp,int argc,char ** argv)
{
fprintf (fp,
"Usage: %s [options]\n\n"
"Options:\n"
"-d | --device name Video device name [/dev/video]\n"
"-h | --help Print this message\n"
"-t | --how long will display in seconds\n"
"",
argv[0]);
}
 
static const char short_options [] = "d:ht:";
static const struct option long_options [] = {
	{ "device", required_argument, NULL, 'd' },
	{ "help", no_argument, NULL, 'h' },
	{ "time", no_argument, NULL, 't' },
	{ 0, 0, 0, 0 }
};
 
int main (int argc,char ** argv)
{
//	dev_name = "/dev/video32";
#if 1		
	for (;;)  
	{
		int index;
		int c;

		c = getopt_long (argc, argv,short_options, long_options,&index);
		if (-1 == c)
			break;

		switch (c) {
			case 0:
				break;

			case 'd':
				dev_name = optarg;
				break;

			case 'h':
				usage (stdout, argc, argv);
				exit (EXIT_SUCCESS);
			case 't':
				time_in_sec_capture = atoi(optarg);
				break;

			default:
				usage (stderr, argc, argv);
				exit (EXIT_FAILURE);
				break;
		}
	}
#endif
	open_device ();	// open fb & camera device

	init_device ();

	start_capturing ();

	run ();

	stop_capturing ();

	uninit_device ();

	close_device ();

	exit (EXIT_SUCCESS);

	return 0;
}