在2440里面添加截屏功能

gsnap.c

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/mman.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <linux/fb.h>

#include <linux/kd.h>

#include <string.h>

#include "jpeglib.h"



struct FB 

{

	int fd;

	unsigned size;

	unsigned short *bits;

	struct fb_fix_screeninfo fi;

	struct fb_var_screeninfo vi;

};



#define fb_width(fb) ((fb)->vi.xres)

#define fb_height(fb) ((fb)->vi.yres)

#define fb_size(fb) ((fb)->vi.xres * (fb)->vi.yres * 2)



static int fb_open(struct FB *fb, const char* fbfilename)

{

	fb->fd = open(fbfilename, O_RDWR);

	if (fb->fd < 0)

	{

		fprintf(stderr, "can't open %s\n", fbfilename);

		return -1;

	}



	if (ioctl(fb->fd, FBIOGET_FSCREENINFO, &fb->fi) < 0)

		goto fail;

	if (ioctl(fb->fd, FBIOGET_VSCREENINFO, &fb->vi) < 0)

		goto fail;



	fb->bits = mmap(0, fb_size(fb), PROT_READ | PROT_WRITE, 

					MAP_SHARED, fb->fd, 0);

	if (fb->bits == MAP_FAILED)

		goto fail;



	return 0;

fail:

	printf("%s is not a framebuffer.\n", fbfilename);

	close(fb->fd);



	return -1;

}



static void fb_close(struct FB *fb)

{

	munmap(fb->bits, fb_size(fb));

	close(fb->fd);

}



static int snap(const char * filename, int quality, struct FB* fb)

{

	int row_stride = 0; 

	const char fullpath[]="/PIC/";//默认存储路径

	const char exname[]=".jpg"; //默认存储图片类型

	FILE * outfile = NULL;

	JSAMPROW row_pointer[1] = {0};

	struct jpeg_error_mgr jerr = {0};

	struct jpeg_compress_struct cinfo = {0};



	cinfo.err = jpeg_std_error(&jerr);

	jpeg_create_compress(&cinfo);

	strcat(fullpath,filename);

	strcat(fullpath,exname);



	if ((outfile = fopen( fullpath, "wb+" )) == NULL) 

	{

		fprintf(stderr, "can't open %s\n", filename);



		return -1;

	}



	jpeg_stdio_dest(&cinfo, outfile);

	cinfo.image_width = fb_width(fb);

	cinfo.image_height = fb_height(fb);

	cinfo.input_components = 3;

	cinfo.in_color_space = JCS_RGB;

	jpeg_set_defaults(&cinfo);

	jpeg_set_quality(&cinfo, quality, TRUE);

	jpeg_start_compress(&cinfo, TRUE);



	row_stride = fb_width(fb) * 2;

	JSAMPLE* image_buffer = malloc(3 * fb_width(fb));



	while (cinfo.next_scanline < cinfo.image_height) 

	{

		int i = 0;

		unsigned short* line = fb->bits + cinfo.next_scanline * fb_width(fb);

		for(i = 0; i < fb_width(fb); i++)

		{

			int offset = i * 3;

			unsigned short color = line[i];

			unsigned char r = ((color >> 11) & 0xff) << 3;

			unsigned char g = ((color >> 5) & 0xff)  << 2;

			unsigned char b = (color & 0xff )<< 3;

			image_buffer[offset]     = r;

			image_buffer[offset + 1] = g;

			image_buffer[offset + 2] = b;

		}



		row_pointer[0] = image_buffer;

		(void) jpeg_write_scanlines(&cinfo, row_pointer, 1);

	}



	jpeg_finish_compress(&cinfo);

	fclose(outfile);



	jpeg_destroy_compress(&cinfo);



	return 0;

}



int main(int argc, char* argv[])

{

	struct FB fb = {0};

	const char* filename   = NULL;

	const char* fbfilename = NULL;



	if(argc >= 3)

	{	

		printf("\nusage: %s [jpeg] \n", argv[0]);

		printf("-----------------------------------------\n");

		return 0;

	}

	filename    = argv[1];

	fbfilename  = "/dev/fb0";

	if (fb_open(&fb,fbfilename) == 0)

	{

		snap(filename, 100, &fb);

		fb_close(&fb);

	}



	return 0;

}

 Makefile

all:

	arm-linux-gcc -g gsnap.c -ljpeg -o gsnap

clean:

	rm -f gsnap

 将生成的gsnap文件加入到/bin文件中即可……