S3C2440 is displayed on LCD through v4l2 acquisition

#include 
#include 
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//#include 
#include 
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#include 

 

#define COLS 320
#define ROWS 240
#define V4L2_DEV_NODE "/dev/video13"
#define FB_DEV_NODE "/dev/fb0"

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

typedef struct v4l2_format   V_FORMAT;
typedef struct fb_var_screeninfo F_VINFO;

struct fb_var_screeninfo fb_var;
struct fb_fix_screeninfo fb_fix;
char * fb_base_addr = NULL;

static void show_rgb565_img(void *scr, __u16 *data_buf)
{ 

	__u16 x, y;
	__u16 *fb_buf = (__u16 *)scr;
	fb_buf += (320);

	for (y = 0; y < ROWS; y++) {
		for (x = 0; x < COLS; x++) { 
			fb_buf[x] = *data_buf++ ;
		}
		fb_buf += 320;
	}
}

int main(void)
{

	int v4l2_fd = -1;
	int fb_fd = -1;
	int n=0;
	__u8 *fb_buf;
	__u8 *buf;
	__u32 screensize;
 
 	//unsigned int width = 0;
	//unsigned int height = 0;
	//unsigned int bpp = 0;

	V_FORMAT fmt;
	enum v4l2_buf_type type;
	type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
	printf("Start Main \n");
	printf("Before openning video \n");
 
	v4l2_fd = open(V4L2_DEV_NODE, O_RDWR | O_NONBLOCK, 0);
 
	if (v4l2_fd < 0) {
		printf(" open video ERR\n");
		return 0;
	}
	printf("Before openning FB \n");
 
	fb_fd = open(FB_DEV_NODE, O_RDWR);
	if (fb_fd < 0) {
		printf("error open fb_fd\n");
		exit(1);
	}

	/* Get fixed screen information */
	if (ioctl(fb_fd, FBIOGET_FSCREENINFO, &fb_fix)) {
		printf("Error reading fb fixed information.\n");
		exit(1);
	}

	/* Get variable screen information 	*/
	if (ioctl(fb_fd, FBIOGET_VSCREENINFO, &fb_var)) {
		printf("Error reading fb variable information.\n");
		exit(1);
	}
 
	screensize = fb_var.xres * fb_var.yres * fb_var.bits_per_pixel / 8;
	//screensize = 480 * 272 * 16 / 8;
 
	fb_buf = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fb_fd, 0);

	if ((int)fb_buf == -1) {
		printf("Error: failed to map framebuffer device to memory.\n");
		close(fb_fd);
		return -1;
	}

	CLEAR (fmt);
	fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
	fmt.fmt.pix.width = 320;
	fmt.fmt.pix.height = 240;
	//fmt.fmt.pix.depth = 16;
	fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB565;
	//printf("VIDIOC_S_FMT is %x\n",VIDIOC_S_FMT);

	if ((ioctl(v4l2_fd, VIDIOC_S_FMT, &fmt)) < 0) {
		printf("Error: failed to set video format.\n");
		return 0;
	}

	buf = malloc(320 * 240 * 3); 
	//printf("VIDIOC_STREAMON is %x\n",VIDIOC_STREAMON);
 
	if ((ioctl(v4l2_fd, VIDIOC_STREAMON, &type)) < 0) {
		printf("error ioctl streamon\n");
		return 0;
	}

	printf("start to get pic %d\n",(int)fmt.fmt.pix.sizeimage);
	while(1) {
		n=read(v4l2_fd, buf, 320*240*2);
		printf("display %d\n",n);
		show_rgb565_img(fb_buf,buf);
	}
}