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写操作手册的时候可能会用到,抓出来的图片肯定比拿相机对着显示器照的效果要真实
- #include <stdio.h>
- #include <unistd.h>
- #include <stdlib.h>
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <fcntl.h>
- #include <linux/fb.h>
- #include <sys/ioctl.h>
- typedef unsigned char BYTE;
- typedef unsigned short WORD;
- typedef unsigned int DWORD;
- typedef long LONG;
- typedef struct tagBITMAPFILEHEADER {
- WORD bfType;
- DWORD bfSize;
- WORD bfReserved1;
- WORD bfReserved2;
- DWORD bfOffBits;
- }__attribute__((packed)) BITMAPFILEHEADER, *PBITMAPFILEHEADER;
- typedef struct tagBITMAPINFOHEADER {
- DWORD biSize;
- LONG biWidth;
- LONG biHeight;
- WORD biPlanes;
- WORD biBitCount;
- DWORD biCompression;
- DWORD biSizeImage;
- LONG biXPelsPerMeter;
- LONG biYPelsPerMeter;
- DWORD biClrUsed;
- DWORD biClrImportant;
- }__attribute__((packed)) BITMAPINFOHEADER, *PBITMAPINFOHEADER;
- typedef struct tagRGBQUAD {
- BYTE rgbBlue;
- BYTE rgbGreen;
- BYTE rgbRed;
- BYTE rgbReserved;
- }__attribute__((packed)) RGBQUAD;
- #define FRAME_BUFFER_PATH "/dev/fb0"
- int main(int argc, char *argv[])
- {
- int i;
- int img_fd, fb_fd;
- int data_size;
- char *img_buf;
- struct fb_var_screeninfo var_info;
- BITMAPFILEHEADER file_head;
- BITMAPINFOHEADER info_head;
- //RGBQUAD rgb_quad;
-
- if (argc != 2)
- {
- printf("usage %s bmp_file\n", argv[0]);
- return -1;
- }
-
- /*open files*/
- fb_fd = open(FRAME_BUFFER_PATH, O_RDWR);
- if (img_fd < 0)
- {
- perror("open framebuff");
- return -1;
- }
- if (ioctl(fb_fd, FBIOGET_VSCREENINFO, &var_info) < 0)
- {
- perror("ioctl FBIOGET_VSCREENINFO");
- close(img_fd);
- return 0;
- }
- printf("xres %d, yres %d\n", var_info.xres, var_info.yres);
-
- img_fd = open(argv[1], O_RDWR | O_CREAT, 0644);
- if (img_fd < 0)
- {
- perror("open image");
- close(img_fd);
- return -1;
- }
-
- data_size = var_info.xres*var_info.yres*(var_info.bits_per_pixel/8);
- /*initialize bmp structs*/
- file_head.bfType = 0x4d42;
- file_head.bfSize = sizeof(file_head) + sizeof(info_head) + data_size;
- file_head.bfReserved1 = file_head.bfReserved2 = 0;
- file_head.bfOffBits = sizeof(file_head) + sizeof(info_head);
-
- info_head.biSize = sizeof(info_head);
- info_head.biWidth = var_info.xres;
- info_head.biHeight = var_info.yres;
- info_head.biPlanes = 1;
- info_head.biBitCount = var_info.bits_per_pixel;
- info_head.biCompression = 0;
- info_head.biSizeImage = 0;
- info_head.biXPelsPerMeter = 0;
- info_head.biYPelsPerMeter = 0;
- info_head.biClrUsed = 0;
- info_head.biClrImportant = 0;
-
- img_buf = (char *)malloc(data_size);
- if (img_buf == NULL)
- {
- printf("malloc failed!\n");
- close(fb_fd);
- close(img_fd);
- return -1;
- }
-
- /*read img data and */
- read(fb_fd, img_buf, data_size);
-
- write(img_fd, &file_head, sizeof(file_head));
- write(img_fd, &info_head, sizeof(info_head));
-
- /*revese img and write to file*/
- for (i = 0; i < var_info.yres; i++)
- {
- write(img_fd, img_buf + var_info.xres*(var_info.yres-i-1)*(var_info.bits_per_pixel/8),
- var_info.xres*(var_info.bits_per_pixel/8));
- }
-
- close(fb_fd);
- close(img_fd);
- return 0;
- }
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