frame-buffer

 
include <sys/types.h>  
#include <sys/stat.h>  
#include <fcntl.h>  
#include <sys/ioctl.h>  
#include <sys/soundcard.h>  
#include <stdio.h>  
#include <unistd.h>  
#include <math.h>  
#include <string.h>  
#include <stdlib.h>  
  #
static unsigned char sg_BHeader[] = {  
    0x42, 0x4D, 0x36, 0x58, 0x02, 0x00, 0x00, 0x00,  0x00, 0x00, 0x36, 0x00, 0x00, 0x00, 0x28, 0x00,   
    0x00, 0x00, 0x40, 0x01, 0x00, 0x00, 0xF0, 0x00,  0x00, 0x00, 0x01, 0x00, 0x10, 0x00, 0x00, 0x00,   
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,   
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00  
};  
#define RGB565TO1555(rgb) ((unsigned short)((unsigned short)(rgb & 0x001f) | ((unsigned short)(rgb & 0xffc0) >> 1)))  
void SaveBMPFile(unsigned char *raw, char *filename)  
{  
    unsigned short *p = (unsigned short *)raw;  
    typedef unsigned int UINT;  
    typedef unsigned char UCHAR;  
    UINT m_Width = 800, m_Height = 480;  
    UINT i, j;  
    int bmp = open(filename, O_WRONLY | O_CREAT);  
    if(bmp < 0)  
        return;  
    sg_BHeader[0x02] = (UCHAR)(m_Width * m_Height * 2 + 0x36) & 0xff;  
    sg_BHeader[0x03] = (UCHAR)((m_Width * m_Height * 2 + 0x36) >> 8) & 0xff;  
    sg_BHeader[0x04] = (UCHAR)((m_Width * m_Height * 2 + 0x36) >> 16) & 0xff;  
    sg_BHeader[0x05] = (UCHAR)((m_Width * m_Height * 2 + 0x36) >> 24) & 0xff;  
    sg_BHeader[0x12] = (UCHAR)m_Width & 0xff;  
    sg_BHeader[0x13] = (UCHAR)(m_Width >> 8) & 0xff;  
    sg_BHeader[0x14] = (UCHAR)(m_Width >> 16) & 0xff;  
    sg_BHeader[0x15] = (UCHAR)(m_Width >> 24) & 0xff;  
    sg_BHeader[0x16] = (UCHAR)m_Height & 0xff;  
    sg_BHeader[0x17] = (UCHAR)(m_Height >> 8) & 0xff;  
    sg_BHeader[0x18] = (UCHAR)(m_Height >> 16) & 0xff;  
    sg_BHeader[0x19] = (UCHAR)(m_Height >> 24) & 0xff;  
    write(bmp, sg_BHeader, sizeof(sg_BHeader));  
    for(i = 0; i < m_Height; i++)  
    {  
        unsigned short *c = p + (m_Height - 1 - i) * m_Width;  
        unsigned short cc;  
        for(j = 0; j < m_Width; j++)  
        {  
            cc = RGB565TO1555(*(c + j));  
//            cc = *(c + j);  
            write(bmp, &cc, 2);  
        }  
    }  
    close(bmp);  
}  
int main(int argc, char *argv[])  
{  
    unsigned char buf[800*480*2];  
    char *filename;  
    int fb;  
  
      
    fb = open("/dev/fb0", O_RDONLY);  
    if(fb < 0)  
        exit(1);  
    if(argc == 2)  
        filename = argv[1];  
    else  
        exit(1);  
    printf("reading screen...\n");  
    read(fb, buf, 800*480*2);  
    close(fb);  
    printf("saving screen...\n");  
    SaveBMPFile(buf, filename);  
    printf("file %s created successfully\n", filename);  
    exit(0);  
}