嵌入式linux截屏程序

基于网上一个代码改的。

源地址：http://blog.csdn.net/z1179675084/article/details/14645359

// 注意，由于fb_bpp = 16的情况没用到，以下修改后的代码只调整了fb_bpp不为16的情况

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <ctype.h>
#include <errno.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <asm/types.h>
#include <linux/videodev2.h>
#include <linux/fb.h>

static unsigned int capframe = 0;
static unsigned char filename[30];
FILE *bmpFile;

unsigned char bmp_head_t[] = {
0x42,0x4d,0x42,0x58,0x02,0x00,0x00,0x00,0x00,0x00,
0x42,0x00,0x00,0x00,0x28,0x00,0x00,0x00,0xf0,0x00,
0x00,0x00,0x40,0x01,0x00,0x00,0x01,0x00,0x10,0x00,
0x03,0x00,0x00,0x00,0x00,0x58,0x02,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0xf8,0x00,0x00,0xe0,0x07,
0x00,0x00,0x1f,0x00,0x00,0x00
};

static int fb_bpp;

//14byte
typedef struct
{
char cfType[2];         /* 文件类型, 必须为 "BM" (0x4D42)*/
unsigned int cfSize;         /* 文件的大小(字节) */
unsigned int cfReserved;     /* 保留, 必须为 0 */
unsigned int cfoffBits;      /* 位图阵列相对于文件头的偏移量(字节)*/
}__attribute__((packed)) BITMAPFILEHEADER;       /* 文件头结构 */

//40byte
typedef struct
{
unsigned int ciSize;         /* size of BITMAPINFOHEADER */
unsigned int ciWidth;        /* 位图宽度(像素) */
unsigned int ciHeight;       /* 位图高度(像素) */
unsigned short ciPlanes;       /* 目标设备的位平面数, 必须置为1 */
unsigned short ciBitCount;     /* 每个像素的位数, 1,4,8或24 */
unsigned int ciCompress;     /* 位图阵列的压缩方法,0=不压缩 */
unsigned int ciSizeImage;    /* 图像大小(字节) */
unsigned int ciXPelsPerMeter;/* 目标设备水平每米像素个数 */
unsigned int ciYPelsPerMeter;/* 目标设备垂直每米像素个数 */
unsigned int ciClrUsed;      /* 位图实际使用的颜色表的颜色数 */
unsigned int ciClrImportant; /* 重要颜色索引的个数 */
}__attribute__((packed)) BITMAPINFOHEADER;       /* 位图信息头结构 */

BITMAPFILEHEADER FileHead;
BITMAPINFOHEADER InfoHead;

unsigned char bmp_head[54];

static int fb_fp = -1;
static char *fb_addr = NULL;

int width=0;
int height=0;

static inline int fb_init(void)
{
int dev_fp = -1;
int fb_size;
struct fb_var_screeninfo vinfo;

dev_fp = open("/dev/fb0", O_RDWR);
if (dev_fp < 0) {
perror("/dev/fb0");
return -1;
}
if (ioctl(dev_fp, FBIOGET_VSCREENINFO, &vinfo)) {
printf("Error reading variable information.\n");
exit(1);
}
width=vinfo.xres;
height=vinfo.yres;
fb_bpp=vinfo.bits_per_pixel;
//if(fb_bpp==24) fb_bpp=32;
fb_size=width*height*fb_bpp/8;
if ((fb_addr = (char*)mmap(0, fb_size,
PROT_READ | PROT_WRITE, MAP_SHARED, dev_fp, 0)) < 0) {
perror("mmap()");
return -1;
}
printf("%dx%d bpp:%d mmaped 0x%08x\n",width,height,fb_bpp,fb_addr);

return dev_fp;
}

void writeImageToFile(unsigned int size)
{
sprintf(filename,"/mnt/sd/0%d.bmp",capframe);
bmpFile=fopen(filename, "w+");
if(fb_bpp == 16)
fwrite(bmp_head_t,1,66,bmpFile);
else
{
fwrite(&FileHead,1,14,bmpFile);
fwrite(&InfoHead,1,40,bmpFile);
}
//fwrite(fb_addr,1,size,bmpFile);
int h = 0;
for (h = height-1; h > 0; h--)
{
fwrite(fb_addr + h * width*fb_bpp/8, 1, width*fb_bpp/8, bmpFile);
}
fclose(bmpFile);

printf("%s\n", filename);
}

int main(int argc, char *argv[])
{
unsigned int i = 10;
unsigned long size = 0;
fb_fp = fb_init();
size=width*height*fb_bpp/8;

if (argc < 2)
{
printf("run like 'prntscr num', num is bmpname'\n");
return 0;
}

capframe = atoi(argv[1]);

if(fb_bpp==16){
*((unsigned int*)(bmp_head_t+18)) = width;
*((unsigned int*)(bmp_head_t+22)) = height;
*((unsigned short*)(bmp_head+28)) = 16;
}else{
FileHead.cfType[0] = 'B';
FileHead.cfType[1] = 'M';
unsigned int tmp = width*height*fb_bpp/8;+54;
FileHead.cfSize = tmp;
FileHead.cfoffBits = 54;
InfoHead.ciSize = 40;
InfoHead.ciWidth = width;
InfoHead.ciHeight = height;
InfoHead.ciBitCount = 32;
InfoHead.ciCompress = 0;
InfoHead.ciSizeImage = size;
}

//while(i--)
{
writeImageToFile(size);

}

return 0;
}