TQ2440摄像头camera图像捕捉测试程序源码

以下这段代码来自天嵌ARM开发社区,采用OV9650视频控制芯片

/*
 *   TQ2440 camera test program
 *
 *   preview : 320x240 overlay on 320x240 16bpp LCD
 *
 *   TFT LCD size : 320x240
 */
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
 
#include
#include
#include "videodev.h"
#include "videodev2.h"
#include
 
#define PIXFMT_NUM            5
#define INPUT_NUM             5
#define CTRL_NUM             100
 
#define V4L2_DEV_NODE            "/dev/v4l/video0"      //for 2.6
#define FB_DEV_NODE            "/dev/fb/0"

//typedef struct v4l2_input    V_INPUT;
//typedef struct v4l2_format   V_FORMAT;
//typedef struct v4l2_fmtdesc  V_FMTDESC;
//typedef struct v4l2_queryctrl V_QRYCTRL;
 
typedef struct fb_var_screeninfo F_VINFO;
 
unsigned int x_lcd_size, y_lcd_size;
 
static void v4l2_show_on_fb(int fd, char *fbmem, int frames)
{
    int i;
    int ret;
    char preview_buf[240*320*2];
 
    while(1) {
            if ((ret = read (fd, &preview_buf, 240*320*2)) < 0) {
                perror("read");
                return;
            }
    #if 1            //for 320*240,640*480,800*480
            {
            int y;
            for (y = 0; y < 240; y++) 
                memcpy(fbmem + x_lcd_size*2*y, preview_buf + 320*2*y, 320*2);
            }
    #else            //for 240*320
            memcpy(fbmem, &preview_buf, 240*320*2);
    #endif
            fflush(stdout);
     

     
    printf("\n");
}
 
static unsigned int fb_grab(int fd, char **fbmem)
{
    F_VINFO modeinfo;
    unsigned int length;
 
    if (ioctl(fd, FBIOGET_VSCREENINFO, &modeinfo) < 0) {
        perror("FBIOGET_VSCREENINFO");
        exit (EXIT_FAILURE);
    }
    length = modeinfo.xres * modeinfo.yres * (modeinfo.bits_per_pixel >> 3);
 
    x_lcd_size=modeinfo.xres;             //width of tft lcd
    y_lcd_size=modeinfo.yres;             //height of tft lcd
 
    printf("fb memory info=xres (%d) x yres (%d), %d bpp\n",
            modeinfo.xres, modeinfo.yres, modeinfo.bits_per_pixel);
 
    *fbmem = mmap(0, length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (*fbmem < 0) {
        perror("mmap()");
        length = 0;
    }
 
    return length;
}
 
static void fb_ungrab(char **fbmem, unsigned int length)
{
    if (*fbmem)
        munmap(*fbmem, length);
}
 
 
int main(int argc, char *argv[])
{
    int v4l2_fd = -1;
    int fb_fd = -1;
    char *fbmem = NULL;
    unsigned int fb_length = 0;

    int preview_frames = 180;
    int tmp;

    printf("TQ2440 Camera Test Program, Start !\n")
    if (argc > 1) {
        if (sscanf(argv[1], "%d", &tmp) == 1)
            preview_frames = tmp;
    }
 
    v4l2_fd = open(V4L2_DEV_NODE, O_RDWR);
    if (v4l2_fd < 0) {
        perror(V4L2_DEV_NODE);
        goto out;
    }
 
    fb_fd = open(FB_DEV_NODE, O_RDWR);
    if (fb_fd < 0) {
        perror(FB_DEV_NODE);
        goto out;
    }
     
    fflush(stdout);
    if ((fb_length = fb_grab(fb_fd, &fbmem)) == 0)
        goto out;
    memset(fbmem, 0, fb_length);

    printf("Press Ctrl+C to stop !\n");
    fflush(stdout);
 
    v4l2_show_on_fb(v4l2_fd, fbmem, preview_frames);
     
    printf("\n");
 
out:
 
    if (v4l2_fd > 0)
        close(v4l2_fd);
 
    fb_ungrab(&fbmem, fb_length);
 
    return 0;
}