row_pointer[0] = & bits[(cinfo.image_height - cinfo.next_scanline - 1) * row_stride];
#include "stdafx.h"
#include <atlbase.h>
#include <afxwin.h>
#include <WINDOWSX.H>
#define JPEG_QUALITY 50
//它的大小決定jpg的質量好壞 extern "C" {
#include "jpeglib.h"
#include "jmorecfg.h"
#include "jconfig.h"
}
int savejpeg(
char *filename, unsigned
char *bits,
int width,
int height,
int depth);
void CapScreen(
char filename[]);
BYTE *image_buffer;
//指向位圖buffer的全局指針，window下像素格式: BGRA(4個字節)
int main(
int argc,
char* argv[])
{
image_buffer = (BYTE *)malloc(1440 * 900 * 4);
for(
int i = 0; i < 100; i++){
CapScreen("ok.bmp");
//RGB順序調整
for (
int i=0,
int j=0; j < 1440*900*4; i+=3, j+=4)
{
*(image_buffer+i)=*(image_buffer+j+2);
*(image_buffer+i+1)=*(image_buffer+j+1);
*(image_buffer+i+2)=*(image_buffer+j);
}
savejpeg("ok.jpg", image_buffer, 1440, 900, 3);
}
delete [] image_buffer;
return 0;
}
/*===================================================================================
function: jpeg壓縮
input: 1:生成的文件名,2:bmp的指針,3:位圖寬度,4:位圖高度,5:顏色深度
return: int
description: bmp的像素格式為(RGB)
===================================================================================*/int savejpeg(
char *filename, unsigned
char *bits,
int width,
int height,
int depth)
{
struct jpeg_compress_struct cinfo;
struct jpeg_error_mgr jerr;
FILE * outfile;
/* target file */ JSAMPROW row_pointer[1];
/* pointer to JSAMPLE row[s] */ int row_stride;
/* physical row width in image buffer */ cinfo.err = jpeg_std_error(&jerr);
jpeg_create_compress(&cinfo);
if ((outfile = fopen(filename, "wb")) == NULL) {
fprintf(stderr, "can't open %s/n", filename);
return -1;
}
jpeg_stdio_dest(&cinfo, outfile);
cinfo.image_width = width;
/* image width and height, in pixels */ cinfo.image_height = height;
cinfo.input_components = 3;
/* # of color components per pixel */ cinfo.in_color_space = JCS_RGB;
/* colorspace of input image */ jpeg_set_defaults(&cinfo);
jpeg_set_quality(&cinfo, JPEG_QUALITY, TRUE
/* limit to baseline-JPEG values */);
jpeg_start_compress(&cinfo, TRUE);
row_stride = width * depth;
/* JSAMPLEs per row in image_buffer */ while (cinfo.next_scanline < cinfo.image_height) {
//這里我做過修改，由于jpg文件的圖像是倒的，所以改了一下讀的順序
//這是原代碼：row_pointer[0] = & bits[cinfo.next_scanline * row_stride];
row_pointer[0] = & bits[(cinfo.image_height - cinfo.next_scanline - 1) * row_stride];
(
void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
}
jpeg_finish_compress(&cinfo);
fclose(outfile);
jpeg_destroy_compress(&cinfo);
return 0;
}
void CapScreen(
char filename[])
{
CDC *pDC;
pDC = CDC::FromHandle(GetDC(GetDesktopWindow()));
if(pDC == NULL)
return;
int BitPerPixel = pDC->GetDeviceCaps(BITSPIXEL);
int Width = pDC->GetDeviceCaps(HORZRES);
int Height = pDC->GetDeviceCaps(VERTRES);
CDC memDC;
if(memDC.CreateCompatibleDC(pDC) == 0)
return;
CBitmap memBitmap, *oldmemBitmap;
if(memBitmap.CreateCompatibleBitmap(pDC, Width, Height) == NULL)
return;
oldmemBitmap = memDC.SelectObject(&memBitmap);
if(oldmemBitmap == NULL)
return;
if(memDC.BitBlt(0, 0, Width, Height, pDC, 0, 0, SRCCOPY) == 0)
return;
BITMAP bmp;
memBitmap.GetBitmap(&bmp);
//fp = fopen(filename, "w+b");
BITMAPINFOHEADER bih = {0};
bih.biBitCount = bmp.bmBitsPixel;
bih.biCompression = BI_RGB;
bih.biHeight = bmp.bmHeight;
bih.biPlanes = 1;
bih.biSize =
sizeof(BITMAPINFOHEADER);
bih.biSizeImage = bmp.bmWidthBytes * bmp.bmHeight;
bih.biWidth = bmp.bmWidth;
BITMAPFILEHEADER bfh = {0};
bfh.bfOffBits =
sizeof(BITMAPFILEHEADER) +
sizeof(BITMAPINFOHEADER);
bfh.bfSize = bfh.bfOffBits + bmp.bmWidthBytes * bmp.bmHeight;
bfh.bfType = (WORD)0x4d42;
//fwrite(&bfh, 1, sizeof(BITMAPFILEHEADER), fp);
//fwrite(&bih, 1, sizeof(BITMAPINFOHEADER), fp);
image_buffer =
new BYTE[bmp.bmWidthBytes * bmp.bmHeight];
GetDIBits(memDC.m_hDC,
(HBITMAP) memBitmap.m_hObject,
0,
Height,
image_buffer,
(LPBITMAPINFO) &bih,
DIB_RGB_COLORS);
memDC.SelectObject(oldmemBitmap);
//fwrite(p, 1, 1280 * 800 * 4, fp);
//fclose(fp);
}