//#include "stdafx.h"
#include<stdio.h>
#include "memory.h"
#include<stdlib.h>
//#include "string.h"
extern "C" {
#include "jpeglib.h"
}

#pragma comment(lib, "libjpeg/libjpeg.lib")

#define IMAGESIZE	452400

typedef unsigned long       DWORD;
typedef int                 BOOL;
typedef unsigned char       BYTE;
typedef unsigned short      WORD;
typedef long				LONG;

typedef struct tagBITMAPFILEHEADER {
        WORD    bfType;
        WORD    bfSizeL;
        WORD    bfSizeH;
        WORD    bfReserved1;
        WORD    bfReserved2;
        WORD    bfOffBitsL;
        WORD    bfOffBitsH;
} BITMAPFILEHEADER;



typedef struct tagRGBQUAD {
        BYTE    rgbBlue;
        BYTE    rgbGreen;
        BYTE    rgbRed;
        BYTE    rgbReserved;
} RGBQUAD;

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;
        DWORD      biR;
        DWORD      biG;
        DWORD      biB;
        DWORD      biempty;
} BITMAPINFOHEADER;

typedef struct tagBITMAPINFO {
    BITMAPINFOHEADER    bmiHeader;
    RGBQUAD             bmiColors[1];
} BITMAPINFO;

/***********************************************
*解壓縮jpeg到bmp格式
*對于灰度圖和24位圖，圖像解壓后正常
*對于256色索引位圖，圖像解壓后為灰度圖
**************************************************/
void jpgtobmp(const char *strSourceFileName, const char *strDestFileName)
{
	BITMAPFILEHEADER bfh;		// bmp文件頭
	BITMAPINFOHEADER bih;		// bmp頭信息
	RGBQUAD rq[256];			// 調色板
	DWORD bfSize;
	DWORD bfOffBits;
	WORD RGB;
		printf("%d \n",sizeof(bfh));

	BYTE *data= NULL;//new BYTE[bih.biWidth*bih.biHeight];
	
	
	BYTE *data16 = NULL;
//	WORD *data16 = NULL;


	//BYTE *pDataConv = NULL;//new BYTE[bih.biWidth*bih.biHeight];
	int nComponent = 0;

	// 聲明解壓縮對象及錯誤信息管理器
	struct jpeg_decompress_struct cinfo;
	struct jpeg_error_mgr jerr;

	cinfo.err = jpeg_std_error(&jerr);
	jpeg_create_decompress(&cinfo);

	FILE *f = fopen(strSourceFileName,"rb");
	if (f==NULL)
	{
		printf("Open file error!\n");
		return;
	}
	// 
	jpeg_stdio_src(&cinfo, f);
	jpeg_read_header(&cinfo, TRUE);
	data = new BYTE[cinfo.image_width*cinfo.image_height*3];
	
	
	data16 = new BYTE[cinfo.image_width*cinfo.image_height*2];
//	data16 = new WORD[cinfo.image_width*cinfo.image_height];
	
	
	
	jpeg_start_decompress(&cinfo);

	JSAMPROW row_pointer[1];
	while (cinfo.output_scanline < cinfo.output_height)
	{
		row_pointer[0] = &data[(cinfo.output_height - cinfo.output_scanline-1)*cinfo.image_width*cinfo.num_components];
		jpeg_read_scanlines(&cinfo,row_pointer ,
					1);
	}
	jpeg_finish_decompress(&cinfo);
	jpeg_destroy_decompress(&cinfo);

	fclose(f);

	f=fopen(strDestFileName,"wb");
	if (f==NULL) 
	{
		delete [] data;
		//delete [] pDataConv;
		return;
	}
	
	
	// 寫文件頭

	memset(&bfh,0,sizeof(bfh));
	bfSize = sizeof(bfh)+sizeof(bih);
	printf("%d \n",sizeof(bih));
	bfh.bfSizeH = bfSize/65536;
	bfh.bfSizeL = bfSize%65536;
	bfOffBits = sizeof(bfh)+sizeof(bih);
	bfh.bfOffBitsH = bfOffBits/65536;
	bfh.bfOffBitsL = bfOffBits%65536;
	if (cinfo.num_components==1)
	{
		bfOffBits += 1024;
		bfh.bfOffBitsH = bfOffBits/65536;
		bfh.bfOffBitsL = bfOffBits%65536;
		bfSize += 1024;
		bfh.bfSizeH = bfSize/65536;
		bfh.bfSizeL = bfSize%65536;
	}
	else{
		bfSize += cinfo.image_width*cinfo.image_height*cinfo.num_components;
		bfh.bfSizeH = bfSize/65536;
		bfh.bfSizeL = bfSize%65536;
	}
	bfh.bfType = 0x4d42;
	fwrite(&bfh,sizeof(bfh),1,f);
	// 寫圖像信息
	bih.biBitCount = 16;
	bih.biSize = sizeof(bih);
	bih.biWidth = cinfo.image_width;
	bih.biHeight = cinfo.image_height;
	bih.biPlanes = 1;
	bih.biCompression = 3;
	bih.biSizeImage = cinfo.image_width*cinfo.image_height*2;
	bih.biXPelsPerMeter = 0;
	bih.biYPelsPerMeter = 0;
	bih.biClrUsed = 0;
	bih.biClrImportant = 0;
	bih.biR=0xf800;
	bih.biG=0x7e0;
	bih.biB=0x1f;
	bih.biempty= 0;
	fwrite(&bih,sizeof(bih),1,f);
	
	// 寫調色板
	if (bih.biBitCount==8)
	{
		for (int i=0;i<256;i++)
		{
			rq[i].rgbBlue =i;
			rq[i].rgbGreen = i;
			rq[i].rgbRed = i;
			rq[i].rgbReserved = 0;
		}
		fwrite(rq,1024,1,f);
	}
	
	if (bih.biBitCount==16)
		{
		
			for(int i = 0;i<bih.biWidth*bih.biHeight;i++)
			 {
			BYTE red = data[i*3];
			data[i*3] = data[i*3+2];
			data[i*3+2] = red;
		//	printf("%x \n",data[i]);
		 }
		 
		   for(int j = 0;j<bih.biWidth*bih.biHeight;j++)
		   {
		  	RGB = (data[j*3]>>3) | (data[j*3+1]>>2)<<5 | (data[j*3+2]>>3)<<11; 
		//	printf("%x",RGB);
		   	data16[j*2] = RGB%256;
		  	data16[j*2+1] = RGB/256;
		  }
		  fwrite(data16,cinfo.image_width*cinfo.image_height*2,1,f);
	
		}
	
	if (bih.biBitCount==24)
	{
		// 調整rgb順序
		for (int i = 0;i<bih.biWidth*bih.biHeight;i++)
		{
			BYTE red = data[i*3];
			data[i*3] = data[i*3+2];
			data[i*3+2] = red;
		}
	fwrite(data,cinfo.image_width*cinfo.image_height*3,1,f);
	}
	fclose(f);
	delete [] data;
	delete [] data16;

}

int main()
{
	jpgtobmp("1.jpg","2.bmp");
	return 0;
}