DM8148 摄像头采集 显示 识别测试 三

显示头文件如下：

#ifndef _DISPLAYFB_H_
#define _DISPLAYFB_H_


extern "C"
{
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <linux/fb.h>
#include <linux/ti81xxfb.h>
#include <linux/ti81xxvin.h>
#include<linux/videodev2.h>

}



#define FB_DEV  "/dev/fb0"
#define __fnc__ __FUNCTION__


class CDisplayFB
{

   public:
      CDisplayFB(){printf("display class \n");}
       ~CDisplayFB();
  public:
        int initFB(char * fb_device,const int width,const int height);
        int initFB(char * fb_device);
        int exitFB();
        int copyImageToFB(unsigned char * source, int width,int height);


        unsigned short RGB888toRGB565(unsigned char red,unsigned char green, unsigned char blue);
        int fb_open(char *fb_device);
	int fb_close(int fd);
	int fb_stat(int fd, unsigned int *width, unsigned int *height, unsigned int *    depth);
	void *fb_mmap(int fd, unsigned int screensize);
	void *fd_mmap(int fd, unsigned int filesize);
	int fb_munmap(void *start, size_t length);
	int fb_pixel(void *fbmem, int width, int height,
        int x, int y, unsigned short color);
public:
    int fd;
    unsigned char *buffer;
    struct stat st;

    int fbdev;
    char *fb_device;
    unsigned char *fbmem;
    unsigned char *fdmem;
    unsigned int screensize;
    unsigned int fb_width;
    unsigned int fb_height;
    unsigned int fb_depth;
    unsigned int x;
    unsigned int y;

   struct fb_fix_screeninfo fb_finfo;
   struct fb_var_screeninfo fb_vinfo;
  
}; 

#endif

显示源文件如下：

#include "displayFb.h"



 int CDisplayFB::fb_open(char *fb_device)
{
    int fd;

    if ((fd = open(fb_device, O_RDWR)) < 0) {
        perror(__fnc__);
        return -1;
    }
    return fd;
}


int CDisplayFB::fb_close(int fd)
{
    return (close(fd));
}


/* get framebuffer's width, height, and depth.
 * return 0 if success, else return -1.
 */
int CDisplayFB::fb_stat(int fd, unsigned int *width, unsigned int *height, unsigned int *    depth)
{
    struct fb_fix_screeninfo fb_finfo;
    struct fb_var_screeninfo fb_vinfo;

    if (ioctl(fd, FBIOGET_FSCREENINFO, &fb_finfo)) {
        perror(__fnc__);
        return -1;
    }

    if (ioctl(fd, FBIOGET_VSCREENINFO, &fb_vinfo)) {
        perror(__fnc__);
        return -1;
    }

    *width = fb_vinfo.xres;
    *height = fb_vinfo.yres;
    *depth = fb_vinfo.bits_per_pixel;

    return 0;
}

/* map shared memory to framebuffer device.
 * return maped memory if success
 * else return -1, as mmap dose
 */
void * CDisplayFB::fb_mmap(int fd, unsigned int screensize)
{
    caddr_t fbmem;

    if ((fbmem = ( char *)mmap(0, screensize, PROT_READ | PROT_WRITE,
                    MAP_SHARED, fd, 0)) == MAP_FAILED) {
        perror(__func__);
        return (void *) (-1);
    }

    return fbmem;
}


/* map shared memmory to a opened file */
void *CDisplayFB::fd_mmap(int fd, unsigned int filesize)
{
    caddr_t fdmem;

    if ((fdmem = ( char *)mmap(0, filesize, PROT_READ,
                    MAP_SHARED, fd, 0)) == MAP_FAILED) {
        perror(__func__);
        return (void *) (-1);
    }

    return fdmem;
}

/* unmap map memory for framebuffer device */
int CDisplayFB::fb_munmap(void *start, size_t length)
{
    return (munmap(start, length));
}

/* convert 24bit RGB888 to 16bit RGB565 color format */
unsigned short CDisplayFB::RGB888toRGB565(unsigned char red,
        unsigned char green, unsigned char blue)
{
    unsigned short B = (blue >> 3) & 0x001F;
    unsigned short G = ((green >> 2) << 5) & 0x07E0;
    unsigned short R = ((red >> 3) << 11) & 0xF800;

    return (unsigned short) (R | G | B);
}

/* display a pixel on the framebuffer device.
 * fbmem is the starting memory of framebuffer,
 * width and height are dimension of framebuffer,
 * width and height are dimension of framebuffer,
 * x and y are the coordinates to display,
 * color is the pixel's color value.
 * return 0 if success, otherwise return -1.
 */
int CDisplayFB::fb_pixel(void *fbmem, int width, int height,
        int x, int y, unsigned short color)
{
    if ((x > width) || (y > height))
        return -1;

    unsigned short *dst = ((unsigned short *) fbmem + y * width + x);

    *dst = color;
    return 0;
}




int CDisplayFB::initFB(char * fb_device,const int width,const int height)
{
    /* open framebuffer device */
   // if ((fb_device = getenv("FRAMEBUFFER")) == NULL)
       // fb_device = FB_DEV;
    fbdev = fb_open(fb_device);

   /* get status of framebuffer device */
    fb_stat(fbdev, &fb_width, &fb_height, &fb_depth);
    if(fb_width < width)
	{
     	 fb_width=width;
         printf("fb_width= %d \n", fb_width);
	}
    if(fb_height < height)
	{
   	 fb_height = height;
          printf("fb_height= %d \n",fb_height);
	}
	printf("fb_width= %d \n", fb_width);
	printf("fb_height= %d \n",fb_height);
	

    /* map framebuffer device to shared memory */
    screensize = fb_width * fb_height * fb_depth / 8;
    fbmem = (unsigned char *)fb_mmap(fbdev, screensize);

    if (ioctl(fbdev, FBIOGET_FSCREENINFO, &fb_finfo)) {
        perror(__fnc__);
        return -1;
    }
     printf("ioctl FBIOGET_FSCREENINFO ok\n");

    if (ioctl(fbdev, FBIOGET_VSCREENINFO, &fb_vinfo)) {
        perror(__fnc__);
        return -1;
    }

     printf("ioctl FBIOGET_VSCREENINFO ok\n");

   return 0;
}


int CDisplayFB::initFB(char * fb_device)
{
    /* open framebuffer device */
   // if ((fb_device = getenv("FRAMEBUFFER")) == NULL)
       // fb_device = FB_DEV;
    fbdev = fb_open(fb_device);

   /* get status of framebuffer device */
    fb_stat(fbdev, &fb_width, &fb_height, &fb_depth);
    //fb_width=width;
    //fb_height = height;

    /* map framebuffer device to shared memory */
    screensize = fb_width * fb_height * fb_depth / 8;
    fbmem = (unsigned char *)fb_mmap(fbdev, screensize);

    if (ioctl(fbdev, FBIOGET_FSCREENINFO, &fb_finfo)) {
        perror(__fnc__);
        return -1;
    }
     printf("ioctl FBIOGET_FSCREENINFO ok\n");

    if (ioctl(fbdev, FBIOGET_VSCREENINFO, &fb_vinfo)) {
        perror(__fnc__);
        return -1;
    }

     printf("ioctl FBIOGET_VSCREENINFO ok\n");

   return 0;
}

 int CDisplayFB::copyImageToFB(unsigned char * source, int width,int height)
{
     int x,y;
     for(y = 0; y < height; y++)
     for (x = 0; x < width; x++) {
                * (fbmem + y * fb_width * 4 + x * 4)     = (unsigned char)       source[y * width *3 + x * 3 + 2];
                * (fbmem + y * fb_width * 4 + x * 4 + 1) = (unsigned char)       source[y * width *3 + x * 3 + 1];
                * (fbmem + y * fb_width * 4 + x * 4 + 2) = (unsigned char)       source[y * width *3 + x * 3 + 0];
                * (fbmem + y * fb_width * 4 + x * 4 + 3) = (unsigned char) 0;
            }
  return 0;
}

int CDisplayFB::exitFB()
{
    
    /* unmap framebuffer's shared memory */
    fb_munmap(fbmem, screensize);
    /* close framebuffer device */
    fb_close(fbdev);
   return 0;
}