BMP图像处理（jpeg转bmp，以及bmp图片缩放，附代码）

目录

背景

一、BMP图片讲解：

二、代码：

背景

1、主要记录下BMP图片的功能，里面包括jpeg格式图片转bmp格式的图片，还有bmp图片的缩放，因为bmp格式的图片一般都很大。

2、网上搜的代码，好多的代码都有依赖，有些是依赖libjpeg.dll，有些是boost，有些是opencv，后面废了不少力气终于找到没有依赖的，太爱了，直接上代码了。

一、BMP图片讲解：

1、BMP（Bitmap）是一种常见的图像文件格式，它是一种无损压缩的图像格式，也就是说，它不会丢失图像的任何细节信息。BMP文件可以存储黑白、灰度或彩色图像，并且可以支持多种位深度和分辨率。

2、BMP图片格式：

• BMP格式的文件通常包含一个文件头和一个位图信息头。

文件头包含了文件类型、文件大小、保留字、位图数据偏移量等信息；

位图信息头则包括了图像的宽度、高度、颜色位数、压缩方式、颜色表等信息。

在图像数据中，每个像素都被表示为一组二进制数，其中每个数表示一个颜色分量，如红色、绿色和蓝色。

（1）文件头：bitmap file header

BITMAPFILEHEADER是位图文件头的结构体，用于描述位图文件的格式和属性。

它通常位于位图文件的开头，其长度为14个字节，包含以下字段：

BITMAPFILEHEADER结构体的定义如下：
typedef struct tagBITMAPFILEHEADER {WORD  bfType;//文件类型，必须为"BM"，占用2个字节DWORD bfSize;//文件大小，以字节为单位，占用4个字节WORD  bfReserved1;//bfReserved1和bfReserved2：保留字段，占用各2个字节，通常设置为0。WORD  bfReserved2;DWORD bfOffBits;//bfOffBits：位图数据的偏移量，即位图文件头和位图信息头之后的字节数，占用4个字节。
} BITMAPFILEHEADER;
其中，WORD和DWORD分别表示2个字节和4个字节的无符号整数类型。

（2）位图信息头 ： bitmap info header

BITMAPINFOHEADER是Windows中用于描述位图文件头信息的结构体。

它包含了位图的宽度、高度、颜色位深度等信息，用于解析和显示位图文件。

BITMAPINFOHEADER结构体的定义如下：typedef struct tagBITMAPINFOHEADER {DWORD biSize;//结构体的大小，以字节为单位，必须为40。LONG  biWidth;//位图的宽度，以像素为单位。LONG  biHeight;//位图的高度，以像素为单位。如果值为正数，则表示位图是从上到下的；如果值为负数，则表示位图是从下到上的。WORD  biPlanes;//目标设备的位平面数，必须为1WORD  biBitCount;//每个像素的位数，可以是1、4、8、16、24或32。DWORD biCompression;//指定位图压缩类型。常用的有BI_RGB、BI_RLE8和BI_RLE4。DWORD biSizeImage;//位图数据的大小，以字节为单位。LONG  biXPelsPerMeter;//目标设备水平方向上每米像素数。LONG  biYPelsPerMeter;//目标设备垂直方向上每米像素数。DWORD biClrUsed;//位图实际使用的颜色表中的颜色数。DWORD biClrImportant;//对图像显示有重要影响的颜色索引数。
} BITMAPINFOHEADER, *PBITMAPINFOHEADER;BITMAPINFOHEADER结构体是位图文件格式中重要的一部分，通过解析这些信息，可以正确地显示和处理位图文件。

二、代码：

1、头文件：

/*
* @Description: BMP图片的功能
* @Author: Ivy
* @Date: 2022-04-25 09:34:43
* @LastEditTime: 2023-02-24 11:28:29
* @LastEditors: XTZJ-2022OQEHLZ
*/#pragma once
#include "SingleTon.h"#include 
#include 
#include 
#include  
#include 
#include 
#include using namespace std;#define M_SOF0  0xc0
#define M_DHT   0xc4
#define M_EOI   0xd9
#define M_SOS   0xda
#define M_DQT   0xdb
#define M_DRI   0xdd
#define M_APP0  0xe0static int Zig_Zag[8][8] = { { 0, 1, 5, 6, 14, 15, 27, 28 },
{ 2, 4, 7, 13, 16, 26, 29, 42 },
{ 3, 8, 12, 17, 25, 30, 41, 43 },
{ 9, 11, 18, 24, 37, 40, 44, 53 },
{ 10, 19, 23, 32, 39, 45, 52, 54 },
{ 20, 22, 33, 38, 46, 51, 55, 60 },
{ 21, 34, 37, 47, 50, 56, 59, 61 },
{ 35, 36, 48, 49, 57, 58, 62, 63 }
};#define W1 2841 /* 2048*sqrt(2)*cos(1*pi/16) */
#define W2 2676 /* 2048*sqrt(2)*cos(2*pi/16) */
#define W3 2408 /* 2048*sqrt(2)*cos(3*pi/16) */
#define W5 1609 /* 2048*sqrt(2)*cos(5*pi/16) */
#define W6 1108 /* 2048*sqrt(2)*cos(6*pi/16) */
#define W7 565  /* 2048*sqrt(2)*cos(7*pi/16) *///*************************************************************************************
typedef char CHAR;
typedef short SHORT;
typedef long LONG;typedef unsigned long       DWORD;
typedef int                 BOOL;
typedef unsigned char       BYTE;
typedef unsigned short      WORD;typedef int HFILE;
typedef CHAR *LPSTR, *PSTR;#define FALSE 0
#define TRUE 1//macro definitio
#define WIDTHBYTES(i)    ((i+31)/32*4)
#define PI 3.1415926535
#define FUNC_OK 0
#define FUNC_MEMORY_ERROR 1
#define FUNC_FILE_ERROR 2
#define FUNC_FORMAT_ERROR 3class CBitmap : public SingleTon
{friend class SingleTon;public:CBitmap(void);virtual ~CBitmap(void);public:bool Jpeg2Bmp(const char* pszSrc, int nSrcLength, unsigned char** pszDst, unsigned int& nDstLength);private:int  InitTag();void InitTable();int  Decode();int  DecodeMCUBlock();int  HufBlock(BYTE dchufindex, BYTE achufindex);int  DecodeElement();void IQtIZzMCUComponent(short flag);void IQtIZzBlock(short  *s, int * d, short flag);void GetYUV(short flag);void StoreBuffer();BYTE ReadByte();void Initialize_Fast_IDCT();void Fast_IDCT(int * block);void idctrow(int * blk);void idctcol(int * blk);string getModulePath();bool BmpZoom(BITMAPFILEHEADER head, BITMAPINFOHEADER info, unsigned char** pszSrc, unsigned int nSrcLength, unsigned char** pszDst, unsigned int& nDstLength);private://global variable declaration//char *            hImgData = NULL;//std::shared_ptr hImgData;DWORD              NumColors;DWORD              LineBytes;DWORD              ImgWidth = 0, ImgHeight = 0;char*             lpPtr;////variables used in jpeg functionshort   SampRate_Y_H, SampRate_Y_V;short   SampRate_U_H, SampRate_U_V;short   SampRate_V_H, SampRate_V_V;short   H_YtoU, V_YtoU, H_YtoV, V_YtoV;short   Y_in_MCU, U_in_MCU, V_in_MCU;unsigned char   *lpJpegBuf = NULL;unsigned char   *lp;short   qt_table[3][64];short   comp_num;BYTE   comp_index[3];BYTE      YDcIndex, YAcIndex, UVDcIndex, UVAcIndex;BYTE   HufTabIndex;short      *YQtTable, *UQtTable, *VQtTable;short      code_pos_table[4][16], code_len_table[4][16];unsigned short code_value_table[4][256];unsigned short huf_max_value[4][16], huf_min_value[4][16];short   BitPos, CurByte;short   rrun, vvalue;short   MCUBuffer[10 * 64];int    QtZzMCUBuffer[10 * 64];short   BlockBuffer[64];short   ycoef, ucoef, vcoef;BOOL   IntervalFlag;short   interval = 0;int    Y[4 * 64], U[4 * 64], V[4 * 64];DWORD      sizei, sizej;short    restart;
};#define Bitmap CBitmap::getInstance()

2、源文件：

#include "Jpeg2Bmp.h"#pragma pack(1)
/* constants for the biCompression field */
#define BI_RGB        0L
#define BI_RLE8       1L
#define BI_RLE4       2L
#define BI_BITFIELDS  3Lstatic  long iclip[1024];
static  long *iclp;
BYTE   And[9] = { 0, 1, 3, 7, 0xf, 0x1f, 0x3f, 0x7f, 0xff };#define OLD_BMP_PATH "\\oldBmp.bmp"
#define NEW_BMP_PATH "\\newBmp.bmp"CBitmap::CBitmap(void)
{
}CBitmap::~CBitmap(void)
{
}void CBitmap::GetYUV(short flag)
{short H, VV;short i, j, k, h;int  *buf;int  *pQtZzMCU;buf = Y;pQtZzMCU = QtZzMCUBuffer;switch (flag) {case 0:H = SampRate_Y_H;VV = SampRate_Y_V;buf = Y;pQtZzMCU = QtZzMCUBuffer;break;case 1:H = SampRate_U_H;VV = SampRate_U_V;buf = U;pQtZzMCU = QtZzMCUBuffer + Y_in_MCU * 64;break;case 2:H = SampRate_V_H;VV = SampRate_V_V;buf = V;pQtZzMCU = QtZzMCUBuffer + (Y_in_MCU + U_in_MCU) * 64;break;}for (i = 0; i < VV; i++)for (j = 0; j < H; j++)for (k = 0; k < 8; k++)for (h = 0; h < 8; h++)buf[(i * 8 + k)*SampRate_Y_H * 8 + j * 8 + h] = *pQtZzMCU++;
}void CBitmap::StoreBuffer()
{short i, j;unsigned char  *lpbmp;unsigned char R, G, B;int y, u, v, rr, gg, bb;for (i = 0; i < SampRate_Y_V * 8; i++) {if ((sizei + i) < ImgHeight) {lpbmp = ((unsigned char *)lpPtr + (DWORD)(ImgHeight - sizei - i - 1)*LineBytes + sizej * 3);for (j = 0; j < SampRate_Y_H * 8; j++) {if ((sizej + j) < ImgWidth) {y = Y[i * 8 * SampRate_Y_H + j];u = U[(i / V_YtoU) * 8 * SampRate_Y_H + j / H_YtoU];v = V[(i / V_YtoV) * 8 * SampRate_Y_H + j / H_YtoV];rr = ((y << 8) + 18 * u + 367 * v) >> 8;gg = ((y << 8) - 159 * u - 220 * v) >> 8;bb = ((y << 8) + 411 * u - 29 * v) >> 8;R = (unsigned char)rr;G = (unsigned char)gg;B = (unsigned char)bb;if (rr & 0xffffff00) if (rr > 255) R = 255; else if (rr < 0) R = 0;if (gg & 0xffffff00) if (gg > 255) G = 255; else if (gg < 0) G = 0;if (bb & 0xffffff00) if (bb > 255) B = 255; else if (bb < 0) B = 0;*lpbmp++ = B;*lpbmp++ = G;*lpbmp++ = R;}else  break;}}else break;}
}void CBitmap::Fast_IDCT(int * block)
{short i;for (i = 0; i < 8; i++)idctrow(block + 8 * i);for (i = 0; i < 8; i++)idctcol(block + i);
}string CBitmap::getModulePath()
{char szDir[2048] = { 0 };::GetModuleFileNameA(NULL, szDir, sizeof(szDir));string strResult = szDir;strResult = strResult.substr(0, strResult.find_last_of("\\"));return strResult;
}bool CBitmap::BmpZoom(BITMAPFILEHEADER head, BITMAPINFOHEADER info, unsigned char** pszSrc, unsigned int nSrcLength, unsigned char** pszDst, unsigned int& nDstLength)
{printf("BmpZoom~~调用开始!\n");bool bReturn = false;try{FILE* file = fopen(string(getModulePath() + OLD_BMP_PATH).c_str(), "wb");if (file == NULL)throw - 1;fwrite(*pszSrc, 1, nSrcLength, file);fclose(file);FILE *fpr1 = fopen(string(getModulePath() + OLD_BMP_PATH).c_str(), "rb");FILE *fpw2 = fopen(string(getModulePath() + NEW_BMP_PATH).c_str(), "wb");if (fpr1 == NULL || fpw2 == NULL)throw - 2;//读取原照片的头信息fread(&head, sizeof(BITMAPFILEHEADER), 1, fpr1);fread(&info, sizeof(BITMAPINFOHEADER), 1, fpr1);unsigned int old_width = info.biWidth;//获取原图片的宽unsigned int old_height = info.biHeight;//获取原图片的高//获取原图片的位图数据printf("BmpZoom~~old_width：%d \n", old_width);printf("BmpZoom~~old_height：%d \n", old_height);LONG srcDataLen = old_width*old_height * 3;printf("BmpZoom~~srcDataLen：%d \n", srcDataLen);if (srcDataLen <= 0)throw - 3;unsigned char *src_data = new unsigned char[srcDataLen];if (src_data == NULL)throw - 4;printf("BmpZoom~~fseek!\n");{ // 测试文件的大小int errer = _fseeki64(fpr1, 0, SEEK_END);if (errer != 0){	// 不等0，移动文件光标失败printf("Failed to move cursor!(SEEK_END)\n");return false;}// 获得当前文件指针位置，也就是间接获得文件大小int fileSize = _ftelli64(fpr1);printf("fpr1文件的大小：%d\n ", fileSize);if (fileSize <= 54)throw - 5;errer = _fseeki64(fpr1, 0, SEEK_SET);if (errer != 0) {	// 不等0，移动文件光标失败printf("Failed to move cursor!(SEEK_END)\n");return false;}fileSize = _ftelli64(fpr1);}fseek(fpr1, 54, SEEK_SET);//向后偏移，就算超出文件，也只是指在文件尾部，不会返回-1fread(src_data, old_width*old_height * 3, 1, fpr1);fclose(fpr1);printf("原图片的宽:%d\n", old_width);printf("原图片的高:%d\n", old_height);//修改原照片的宽高unsigned int new_Width, new_Height;old_width > 480 ? new_Width = 480 : new_Width = old_width;old_height > 300 ? new_Height = 300 : new_Height = old_height;unsigned int newSize = new_Width * new_Height * 3;head.bfSize = newSize + 54;info.biWidth = new_Width;info.biHeight = new_Height;//将修改过的头信息写进新照片fwrite(&head, sizeof(BITMAPFILEHEADER), 1, fpw2);fwrite(&info, sizeof(BITMAPINFOHEADER), 1, fpw2);unsigned int i = 0, j = 0;unsigned long dwsrcX, dwsrcY;unsigned char *pucDest;unsigned char *pucSrc;unsigned char *dest_data = new unsigned char[newSize];for (i = 0; i < new_Height; i++){dwsrcY = i * old_height / new_Height;pucDest = dest_data + i * new_Width * 3;pucSrc = src_data + dwsrcY * old_width * 3;for (j = 0; j < new_Width; j++){dwsrcX = j * old_width / new_Width;memcpy(pucDest + j * 3, pucSrc + dwsrcX * 3, 3);//数据拷贝}}fseek(fpw2, 54, SEEK_SET);fwrite(dest_data, newSize, 1, fpw2);printf("生成 压缩bmp图片 成功!\n");fclose(fpw2);nDstLength = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + newSize;*pszDst = new unsigned char[nDstLength];unsigned char* tmpData = *pszDst;memcpy_s(tmpData, sizeof(BITMAPFILEHEADER), &head, sizeof(BITMAPFILEHEADER));tmpData += sizeof(BITMAPFILEHEADER);memcpy_s(tmpData, sizeof(BITMAPINFOHEADER), &info, sizeof(BITMAPINFOHEADER));tmpData += sizeof(BITMAPINFOHEADER);memcpy_s(tmpData, newSize, dest_data, newSize);//释放堆空间delete[] dest_data;dest_data = NULL;delete[] src_data;src_data = NULL;return true;}catch (int& iErrorCode){switch (iErrorCode){case -1:printf("生成old bmp文件 失败!\n");break;case -2:printf("打开old bmp文件 失败 or 生成new bmp文件 失败!\n");break;case -3:printf("BmpZoom~~srcDataLen <=0 返回!\n");break;case -4:printf("BmpZoom~~src_data 申请内存失败!\n");break;case -5:printf("fpr1文件的大小，小于54，返回\n");break;}}return bReturn;
}bool CBitmap::Jpeg2Bmp(const char* pszSrc, int nSrcLength, unsigned char** pszDst, unsigned int& nDstLength)
{FILE*      hfjpg;//打开原本jpg格式的文件DWORD      ImgSize;DWORD      BufSize, JpegBufSize;FILE*      hfbmp;//生成目标bmp文件unsigned char * hJpegBuf = NULL;//存储原本jpg格式的文件数据unsigned char * hImgData = NULL;//存储新的数据的变量int        funcret;LPBITMAPINFOHEADER lpImgData;BITMAPFILEHEADER   bf;//描述位图文件头的结构体BITMAPINFOHEADER   bi;//描述位图文件头信息的结构体printf("传进来的图片路径：%s\n", pszSrc);errno_t err = fopen_s(&hfjpg, pszSrc, "rb");//正确返回0，不正确返回非0if (err != 0){printf("文件打开失败\n");}//get jpg file lengthfseek(hfjpg, 0L, SEEK_END);JpegBufSize = ftell(hfjpg);printf("原本图片数据（JpegBufSize）大小:%d\n", JpegBufSize);//rewind to the beginning of the filefseek(hfjpg, 0L, SEEK_SET);hJpegBuf = new unsigned char[JpegBufSize];if (hJpegBuf == NULL){printf("存储原本jpg格式的文件数据（hJpegBuf） 分配内存失败，返回\n");return false;}lpJpegBuf = hJpegBuf;//多一个变量指向这块内存fread(hJpegBuf, sizeof(char), JpegBufSize, hfjpg);fclose(hfjpg);InitTable();if ((funcret = InitTag()) != FUNC_OK){delete[] hJpegBuf;hJpegBuf = NULL;return false;}//create new bitmapfileheader and bitmapinfoheadermemset((char *)&bf, 0, sizeof(BITMAPFILEHEADER));memset((char *)&bi, 0, sizeof(BITMAPINFOHEADER));bi.biSize = (DWORD)sizeof(BITMAPINFOHEADER);bi.biWidth = (LONG)(ImgWidth);bi.biHeight = (LONG)(ImgHeight);bi.biPlanes = 1;bi.biBitCount = 24;bi.biClrUsed = 0;bi.biClrImportant = 0;bi.biCompression = BI_RGB;NumColors = 0;LineBytes = (DWORD)WIDTHBYTES(bi.biWidth*bi.biBitCount);ImgSize = (DWORD)LineBytes*bi.biHeight;bf.bfType = 0x4d42;printf("描述位图文件头的结构体（BITMAPFILEHEADER）：%d\n", sizeof(BITMAPFILEHEADER));//如果没有#pragma pack(1)，sizeof(BITMAPFILEHEADER)是16printf("描述位图文件头信息的结构体（BITMAPINFOHEADER）：%d\n", sizeof(BITMAPINFOHEADER));printf("NumColors * sizeof(RGBQUAD)：%d\n", NumColors * sizeof(RGBQUAD));bf.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + NumColors * sizeof(RGBQUAD) + ImgSize;bf.bfOffBits = 54;//位图数据的偏移量，即位图文件头和位图信息头之后的字节数BufSize = bf.bfSize - sizeof(BITMAPFILEHEADER); //描述位图文件头的结构体，文件头的结构体的大小是固定的，所以先减去，后面直接复制文件头的结构体即可printf("文件大小(bf.bfSize)：%d\n", bf.bfSize);printf("文件大小 - 位图文件头的结构体 = BufSize：%d\n", BufSize);if (BufSize <= 0){delete[] hJpegBuf;hJpegBuf = NULL;return FALSE;}hImgData = new unsigned char[BufSize];if (hImgData == NULL){printf("hImgData 申请内存失败！\n");delete[] hJpegBuf;hJpegBuf = NULL;return FALSE;}printf("存储新的数据的变量（hImgData） 申请内存成功！\n");lpImgData = (LPBITMAPINFOHEADER)hImgData;printf("sizeof(BITMAPINFOHEADER)：%d\n", sizeof(BITMAPINFOHEADER));printf("sizeof(bi)：%d\n", sizeof(bi));memcpy(lpImgData, (char *)&bi, sizeof(BITMAPINFOHEADER));//描述位图文件头信息的结构体if (lpImgData==NULL){printf("lpImgData = NULL 返回 \n");return false;}printf("sizeof(lpImgData)：%d\n", sizeof(lpImgData));lpPtr = (char *)lpImgData + sizeof(BITMAPINFOHEADER);//mencpy完，指针往后移，并赋给新的全局指针（其他函数做一些格式转换处理）if ((SampRate_Y_H == 0) || (SampRate_Y_V == 0)){delete[] hJpegBuf;hJpegBuf = NULL;delete[] hImgData;hImgData = NULL;printf("(SampRate_Y_H == 0) || (SampRate_Y_V == 0) 失败，返回\n");return false;}printf("Decode接口，调用开始\n");funcret = Decode();//格式转换的主要函数printf("Decode接口，调用结束\n");bool retOK = false;if (funcret == FUNC_OK){//生成bmp图片（可以不生成这个文件的，只是为了看）fopen_s(&hfbmp, string(getModulePath() + "\\jpeg2bmp.bmp").c_str(), "wb");fwrite((LPSTR)&bf, sizeof(BITMAPFILEHEADER), 1, hfbmp);fwrite((LPSTR)lpImgData, sizeof(char), BufSize, hfbmp);fclose(hfbmp);printf(" 生成目标 bmp 图片成功 \n");{//bmp图片转为二进制unsigned int nSrcLength = BufSize + sizeof(BITMAPFILEHEADER);//生成目标bmp文件的大小printf("生成目标bmp文件的大小(nSrcLength)：%d\n", nSrcLength);unsigned char *pszSrcZoom = new unsigned char[nSrcLength]; //申请内存，主要是想把bmp文件的数据读出来if (pszSrcZoom == NULL){printf("pszSrcZoom 申请内存失败！\n");delete[] hJpegBuf;hJpegBuf = NULL;delete[] hImgData;hImgData = NULL;return false;}unsigned char* tmpData = pszSrcZoom;memcpy_s(tmpData, sizeof(BITMAPFILEHEADER), &bf, sizeof(BITMAPFILEHEADER));//位图的文件头结构体tmpData += sizeof(BITMAPFILEHEADER);//指针往后移memcpy_s(tmpData, BufSize, lpImgData, BufSize);//复制bmp的数据printf("测试 ~~~~aaaaaaaaaaaaa\n");unsigned char* pszDstZoom = NULL;//存bmp图片压缩后的数据bool retBmpZoom = BmpZoom(bf, *lpImgData, &pszSrcZoom, nSrcLength, &pszDstZoom, nDstLength);if (pszSrcZoom != NULL){delete[] pszSrcZoom;pszSrcZoom = NULL;}if (retBmpZoom && pszDstZoom != NULL){*pszDst = new unsigned char[nDstLength];if (*pszDst == NULL){printf("*pszDst 申请内存失败！\n");delete[] hJpegBuf;hJpegBuf = NULL;delete[] hImgData;hImgData = NULL;return false;}memcpy_s(*pszDst, nDstLength, pszDstZoom, nDstLength);delete[] pszDstZoom;pszDstZoom = NULL;retOK = true;}}}delete[] hJpegBuf;hJpegBuf = NULL;delete[] hImgData;hImgData = NULL;retOK ? printf("retBmpZoom压缩成功!\n") : printf("retBmpZoom压缩失败!\n");return retOK;
}int CBitmap::InitTag()
{BOOL finish = FALSE;BYTE id;short  llength;short  i, j, k;short  huftab1, huftab2;short  huftabindex;BYTE hf_table_index;BYTE qt_table_index;BYTE comnum;unsigned char  *lptemp;short  ccount;lp = lpJpegBuf + 2;while (!finish) {id = *(lp + 1);lp += 2;switch (id) {case M_APP0:llength = MAKEWORD(*(lp + 1), *lp);lp += llength;break;case M_DQT:llength = MAKEWORD(*(lp + 1), *lp);qt_table_index = (*(lp + 2)) & 0x0f;lptemp = lp + 3;if (llength < 80) {for (i = 0; i < 64; i++)qt_table[qt_table_index][i] = (short)*(lptemp++);}else {for (i = 0; i < 64; i++)qt_table[qt_table_index][i] = (short)*(lptemp++);qt_table_index = (*(lptemp++)) & 0x0f;for (i = 0; i < 64; i++)qt_table[qt_table_index][i] = (short)*(lptemp++);}lp += llength;break;case M_SOF0:llength = MAKEWORD(*(lp + 1), *lp);ImgHeight = MAKEWORD(*(lp + 4), *(lp + 3));ImgWidth = MAKEWORD(*(lp + 6), *(lp + 5));comp_num = *(lp + 7);if ((comp_num != 1) && (comp_num != 3))return FUNC_FORMAT_ERROR;if (comp_num == 3) {comp_index[0] = *(lp + 8);SampRate_Y_H = (*(lp + 9)) >> 4;SampRate_Y_V = (*(lp + 9)) & 0x0f;YQtTable = (short *)qt_table[*(lp + 10)];comp_index[1] = *(lp + 11);SampRate_U_H = (*(lp + 12)) >> 4;SampRate_U_V = (*(lp + 12)) & 0x0f;UQtTable = (short *)qt_table[*(lp + 13)];comp_index[2] = *(lp + 14);SampRate_V_H = (*(lp + 15)) >> 4;SampRate_V_V = (*(lp + 15)) & 0x0f;VQtTable = (short *)qt_table[*(lp + 16)];}else {comp_index[0] = *(lp + 8);SampRate_Y_H = (*(lp + 9)) >> 4;SampRate_Y_V = (*(lp + 9)) & 0x0f;YQtTable = (short *)qt_table[*(lp + 10)];comp_index[1] = *(lp + 8);SampRate_U_H = 1;SampRate_U_V = 1;UQtTable = (short *)qt_table[*(lp + 10)];comp_index[2] = *(lp + 8);SampRate_V_H = 1;SampRate_V_V = 1;VQtTable = (short *)qt_table[*(lp + 10)];}lp += llength;break;case M_DHT:llength = MAKEWORD(*(lp + 1), *lp);if (llength < 0xd0) {huftab1 = (short)(*(lp + 2)) >> 4;     //huftab1=0,1huftab2 = (short)(*(lp + 2)) & 0x0f;   //huftab2=0,1huftabindex = huftab1 * 2 + huftab2;lptemp = lp + 3;for (i = 0; i < 16; i++)code_len_table[huftabindex][i] = (short)(*(lptemp++));j = 0;for (i = 0; i < 16; i++)if (code_len_table[huftabindex][i] != 0) {k = 0;while (k < code_len_table[huftabindex][i]) {code_value_table[huftabindex][k + j] = (short)(*(lptemp++));k++;}j += k;}i = 0;while (code_len_table[huftabindex][i] == 0)i++;for (j = 0; j < i; j++) {huf_min_value[huftabindex][j] = 0;huf_max_value[huftabindex][j] = 0;}huf_min_value[huftabindex][i] = 0;huf_max_value[huftabindex][i] = code_len_table[huftabindex][i] - 1;for (j = i + 1; j < 16; j++) {huf_min_value[huftabindex][j] = (huf_max_value[huftabindex][j - 1] + 1) << 1;huf_max_value[huftabindex][j] = huf_min_value[huftabindex][j] + code_len_table[huftabindex][j] - 1;}code_pos_table[huftabindex][0] = 0;for (j = 1; j < 16; j++)code_pos_table[huftabindex][j] = code_len_table[huftabindex][j - 1] + code_pos_table[huftabindex][j - 1];lp += llength;}  //ifelse {hf_table_index = *(lp + 2);lp += 2;while (hf_table_index != 0xff) {huftab1 = (short)hf_table_index >> 4;     //huftab1=0,1huftab2 = (short)hf_table_index & 0x0f;   //huftab2=0,1huftabindex = huftab1 * 2 + huftab2;lptemp = lp + 1;ccount = 0;for (i = 0; i < 16; i++) {code_len_table[huftabindex][i] = (short)(*(lptemp++));ccount += code_len_table[huftabindex][i];}ccount += 17;j = 0;for (i = 0; i < 16; i++)if (code_len_table[huftabindex][i] != 0) {k = 0;while (k < code_len_table[huftabindex][i]){code_value_table[huftabindex][k + j] = (short)(*(lptemp++));k++;}j += k;}i = 0;while (code_len_table[huftabindex][i] == 0)i++;for (j = 0; j < i; j++) {huf_min_value[huftabindex][j] = 0;huf_max_value[huftabindex][j] = 0;}huf_min_value[huftabindex][i] = 0;huf_max_value[huftabindex][i] = code_len_table[huftabindex][i] - 1;for (j = i + 1; j < 16; j++) {huf_min_value[huftabindex][j] = (huf_max_value[huftabindex][j - 1] + 1) << 1;huf_max_value[huftabindex][j] = huf_min_value[huftabindex][j] + code_len_table[huftabindex][j] - 1;}code_pos_table[huftabindex][0] = 0;for (j = 1; j < 16; j++)code_pos_table[huftabindex][j] = code_len_table[huftabindex][j - 1] + code_pos_table[huftabindex][j - 1];lp += ccount;hf_table_index = *lp;}  //while}  //elsebreak;case M_DRI:llength = MAKEWORD(*(lp + 1), *lp);restart = MAKEWORD(*(lp + 3), *(lp + 2));lp += llength;break;case M_SOS:llength = MAKEWORD(*(lp + 1), *lp);comnum = *(lp + 2);if (comnum != comp_num)return FUNC_FORMAT_ERROR;lptemp = lp + 3;for (i = 0; i < comp_num; i++) {if (*lptemp == comp_index[0]) {YDcIndex = (*(lptemp + 1)) >> 4;   //YYAcIndex = ((*(lptemp + 1)) & 0x0f) + 2;}else {UVDcIndex = (*(lptemp + 1)) >> 4;   //U,VUVAcIndex = ((*(lptemp + 1)) & 0x0f) + 2;}lptemp += 2;}lp += llength;finish = TRUE;break;case M_EOI:return FUNC_FORMAT_ERROR;break;default:if ((id & 0xf0) != 0xd0) {llength = MAKEWORD(*(lp + 1), *lp);lp += llength;}else lp += 2;break;}  //switch} //whilereturn FUNC_OK;
}void CBitmap::InitTable()
{short i, j;sizei = sizej = 0;ImgWidth = ImgHeight = 0;rrun = vvalue = 0;BitPos = 0;CurByte = 0;IntervalFlag = FALSE;restart = 0;for (i = 0; i < 3; i++)for (j = 0; j < 64; j++)qt_table[i][j] = 0;comp_num = 0;HufTabIndex = 0;for (i = 0; i < 3; i++)comp_index[i] = 0;for (i = 0; i < 4; i++)for (j = 0; j < 16; j++) {code_len_table[i][j] = 0;code_pos_table[i][j] = 0;huf_max_value[i][j] = 0;huf_min_value[i][j] = 0;}for (i = 0; i < 4; i++)for (j = 0; j < 256; j++)code_value_table[i][j] = 0;for (i = 0; i < 10 * 64; i++) {MCUBuffer[i] = 0;QtZzMCUBuffer[i] = 0;}for (i = 0; i < 64; i++) {Y[i] = 0;U[i] = 0;V[i] = 0;BlockBuffer[i] = 0;}ycoef = ucoef = vcoef = 0;
}int CBitmap::Decode()
{int funcret;Y_in_MCU = SampRate_Y_H * SampRate_Y_V;U_in_MCU = SampRate_U_H * SampRate_U_V;V_in_MCU = SampRate_V_H * SampRate_V_V;H_YtoU = SampRate_Y_H / SampRate_U_H;V_YtoU = SampRate_Y_V / SampRate_U_V;H_YtoV = SampRate_Y_H / SampRate_V_H;V_YtoV = SampRate_Y_V / SampRate_V_V;Initialize_Fast_IDCT();while ((funcret = DecodeMCUBlock()) == FUNC_OK) {interval++;if ((restart) && (interval % restart == 0))IntervalFlag = TRUE;elseIntervalFlag = FALSE;IQtIZzMCUComponent(0);IQtIZzMCUComponent(1);IQtIZzMCUComponent(2);GetYUV(0);GetYUV(1);GetYUV(2);StoreBuffer();sizej += SampRate_Y_H * 8;if (sizej >= ImgWidth) {sizej = 0;sizei += SampRate_Y_V * 8;}if ((sizej == 0) && (sizei >= ImgHeight))break;}return funcret;
}int CBitmap::DecodeMCUBlock()
{short *lpMCUBuffer;short i, j;int funcret;if (IntervalFlag) {lp += 2;ycoef = ucoef = vcoef = 0;BitPos = 0;CurByte = 0;}switch (comp_num) {case 3:lpMCUBuffer = MCUBuffer;for (i = 0; i < SampRate_Y_H*SampRate_Y_V; i++)  //Y{funcret = HufBlock(YDcIndex, YAcIndex);if (funcret != FUNC_OK)return funcret;BlockBuffer[0] = BlockBuffer[0] + ycoef;ycoef = BlockBuffer[0];for (j = 0; j < 64; j++)*lpMCUBuffer++ = BlockBuffer[j];}for (i = 0; i < SampRate_U_H*SampRate_U_V; i++)  //U{funcret = HufBlock(UVDcIndex, UVAcIndex);if (funcret != FUNC_OK)return funcret;BlockBuffer[0] = BlockBuffer[0] + ucoef;ucoef = BlockBuffer[0];for (j = 0; j < 64; j++)*lpMCUBuffer++ = BlockBuffer[j];}for (i = 0; i < SampRate_V_H*SampRate_V_V; i++)  //V{funcret = HufBlock(UVDcIndex, UVAcIndex);if (funcret != FUNC_OK)return funcret;BlockBuffer[0] = BlockBuffer[0] + vcoef;vcoef = BlockBuffer[0];for (j = 0; j < 64; j++)*lpMCUBuffer++ = BlockBuffer[j];}break;case 1:lpMCUBuffer = MCUBuffer;funcret = HufBlock(YDcIndex, YAcIndex);if (funcret != FUNC_OK)return funcret;BlockBuffer[0] = BlockBuffer[0] + ycoef;ycoef = BlockBuffer[0];for (j = 0; j < 64; j++)*lpMCUBuffer++ = BlockBuffer[j];for (i = 0; i < 128; i++)*lpMCUBuffer++ = 0;break;default:return FUNC_FORMAT_ERROR;}return FUNC_OK;
}int CBitmap::HufBlock(BYTE dchufindex, BYTE achufindex)
{short count = 0;short i;int funcret;//dcHufTabIndex = dchufindex;funcret = DecodeElement();if (funcret != FUNC_OK)return funcret;BlockBuffer[count++] = vvalue;//acHufTabIndex = achufindex;while (count < 64) {funcret = DecodeElement();if (funcret != FUNC_OK)return funcret;if ((rrun == 0) && (vvalue == 0)) {for (i = count; i < 64; i++)BlockBuffer[i] = 0;count = 64;}else {for (i = 0; i < rrun; i++)BlockBuffer[count++] = 0;BlockBuffer[count++] = vvalue;}}return FUNC_OK;
}int CBitmap::DecodeElement()
{int thiscode, tempcode;unsigned short temp, valueex;short codelen;BYTE hufexbyte, runsize, tempsize, sign;BYTE newbyte, lastbyte;if (BitPos >= 1) {BitPos--;thiscode = (BYTE)CurByte >> BitPos;CurByte = CurByte & And[BitPos];}else {lastbyte = ReadByte();BitPos--;newbyte = CurByte & And[BitPos];thiscode = lastbyte >> 7;CurByte = newbyte;}codelen = 1;while ((thiscode < huf_min_value[HufTabIndex][codelen - 1]) ||(code_len_table[HufTabIndex][codelen - 1] == 0) ||(thiscode > huf_max_value[HufTabIndex][codelen - 1])){if (BitPos >= 1) {BitPos--;tempcode = (BYTE)CurByte >> BitPos;CurByte = CurByte & And[BitPos];}else {lastbyte = ReadByte();BitPos--;newbyte = CurByte & And[BitPos];tempcode = (BYTE)lastbyte >> 7;CurByte = newbyte;}thiscode = (thiscode << 1) + tempcode;codelen++;if (codelen > 16)return FUNC_FORMAT_ERROR;}  //whiletemp = thiscode - huf_min_value[HufTabIndex][codelen - 1] + code_pos_table[HufTabIndex][codelen - 1];hufexbyte = (BYTE)code_value_table[HufTabIndex][temp];rrun = (short)(hufexbyte >> 4);runsize = hufexbyte & 0x0f;if (runsize == 0) {vvalue = 0;return FUNC_OK;}tempsize = runsize;if (BitPos >= runsize) {BitPos -= runsize;valueex = (BYTE)CurByte >> BitPos;CurByte = CurByte & And[BitPos];}else {valueex = CurByte;tempsize -= BitPos;while (tempsize > 8) {lastbyte = ReadByte();valueex = (valueex << 8) + (BYTE)lastbyte;tempsize -= 8;}  //whilelastbyte = ReadByte();BitPos -= tempsize;valueex = (valueex << tempsize) + (lastbyte >> BitPos);CurByte = lastbyte & And[BitPos];}  //elsesign = valueex >> (runsize - 1);if (sign)vvalue = valueex;else {valueex = valueex ^ 0xffff;temp = 0xffff << runsize;vvalue = -(short)(valueex^temp);}return FUNC_OK;
}void CBitmap::IQtIZzMCUComponent(short flag)
{short H, VV;short i, j;int *pQtZzMCUBuffer;short  *pMCUBuffer;pMCUBuffer = MCUBuffer;pQtZzMCUBuffer = QtZzMCUBuffer;switch (flag) {case 0:H = SampRate_Y_H;VV = SampRate_Y_V;pMCUBuffer = MCUBuffer;pQtZzMCUBuffer = QtZzMCUBuffer;break;case 1:H = SampRate_U_H;VV = SampRate_U_V;pMCUBuffer = MCUBuffer + Y_in_MCU * 64;pQtZzMCUBuffer = QtZzMCUBuffer + Y_in_MCU * 64;break;case 2:H = SampRate_V_H;VV = SampRate_V_V;pMCUBuffer = MCUBuffer + (Y_in_MCU + U_in_MCU) * 64;pQtZzMCUBuffer = QtZzMCUBuffer + (Y_in_MCU + U_in_MCU) * 64;break;}for (i = 0; i < VV; i++)for (j = 0; j < H; j++)IQtIZzBlock(pMCUBuffer + (i*H + j) * 64, pQtZzMCUBuffer + (i*H + j) * 64, flag);
}void CBitmap::IQtIZzBlock(short  *s, int * d, short flag)
{short i, j;short tag;short *pQt;int buffer2[8][8];int *buffer1;short offset;pQt = YQtTable;switch (flag) {case 0:pQt = YQtTable;offset = 128;break;case 1:pQt = UQtTable;offset = 0;break;case 2:pQt = VQtTable;offset = 0;break;}for (i = 0; i < 8; i++)for (j = 0; j < 8; j++) {tag = Zig_Zag[i][j];buffer2[i][j] = (int)s[tag] * (int)pQt[tag];}buffer1 = (int *)buffer2;Fast_IDCT(buffer1);for (i = 0; i < 8; i++)for (j = 0; j < 8; j++)d[i * 8 + j] = buffer2[i][j] + offset;
}BYTE CBitmap::ReadByte()
{BYTE  i;i = *(lp++);if (i == 0xff)lp++;BitPos = 8;CurByte = i;return i;
}void CBitmap::Initialize_Fast_IDCT()
{short i;iclp = iclip + 512;for (i = -512; i < 512; i++)iclp[i] = (i < -256) ? -256 : ((i > 255) ? 255 : i);
}void CBitmap::idctrow(int * blk)
{int x0, x1, x2, x3, x4, x5, x6, x7, x8;//intcutif (!((x1 = blk[4] << 11) | (x2 = blk[6]) | (x3 = blk[2]) |(x4 = blk[1]) | (x5 = blk[7]) | (x6 = blk[5]) | (x7 = blk[3]))){blk[0] = blk[1] = blk[2] = blk[3] = blk[4] = blk[5] = blk[6] = blk[7] = blk[0] << 3;return;}x0 = (blk[0] << 11) + 128; // for proper rounding in the fourth stage //first stagex8 = W7 * (x4 + x5);x4 = x8 + (W1 - W7)*x4;x5 = x8 - (W1 + W7)*x5;x8 = W3 * (x6 + x7);x6 = x8 - (W3 - W5)*x6;x7 = x8 - (W3 + W5)*x7;//second stagex8 = x0 + x1;x0 -= x1;x1 = W6 * (x3 + x2);x2 = x1 - (W2 + W6)*x2;x3 = x1 + (W2 - W6)*x3;x1 = x4 + x6;x4 -= x6;x6 = x5 + x7;x5 -= x7;//third stagex7 = x8 + x3;x8 -= x3;x3 = x0 + x2;x0 -= x2;x2 = (181 * (x4 + x5) + 128) >> 8;x4 = (181 * (x4 - x5) + 128) >> 8;//fourth stageblk[0] = (x7 + x1) >> 8;blk[1] = (x3 + x2) >> 8;blk[2] = (x0 + x4) >> 8;blk[3] = (x8 + x6) >> 8;blk[4] = (x8 - x6) >> 8;blk[5] = (x0 - x4) >> 8;blk[6] = (x3 - x2) >> 8;blk[7] = (x7 - x1) >> 8;
}void CBitmap::idctcol(int * blk)
{int x0, x1, x2, x3, x4, x5, x6, x7, x8;//intcutif (!((x1 = (blk[8 * 4] << 8)) | (x2 = blk[8 * 6]) | (x3 = blk[8 * 2]) |(x4 = blk[8 * 1]) | (x5 = blk[8 * 7]) | (x6 = blk[8 * 5]) | (x7 = blk[8 * 3]))){blk[8 * 0] = blk[8 * 1] = blk[8 * 2] = blk[8 * 3] = blk[8 * 4] = blk[8 * 5]= blk[8 * 6] = blk[8 * 7] = iclp[(blk[8 * 0] + 32) >> 6];return;}x0 = (blk[8 * 0] << 8) + 8192;//first stagex8 = W7 * (x4 + x5) + 4;x4 = (x8 + (W1 - W7)*x4) >> 3;x5 = (x8 - (W1 + W7)*x5) >> 3;x8 = W3 * (x6 + x7) + 4;x6 = (x8 - (W3 - W5)*x6) >> 3;x7 = (x8 - (W3 + W5)*x7) >> 3;//second stagex8 = x0 + x1;x0 -= x1;x1 = W6 * (x3 + x2) + 4;x2 = (x1 - (W2 + W6)*x2) >> 3;x3 = (x1 + (W2 - W6)*x3) >> 3;x1 = x4 + x6;x4 -= x6;x6 = x5 + x7;x5 -= x7;//third stagex7 = x8 + x3;x8 -= x3;x3 = x0 + x2;x0 -= x2;x2 = (181 * (x4 + x5) + 128) >> 8;x4 = (181 * (x4 - x5) + 128) >> 8;//fourth stageblk[8 * 0] = iclp[(x7 + x1) >> 14];blk[8 * 1] = iclp[(x3 + x2) >> 14];blk[8 * 2] = iclp[(x0 + x4) >> 14];blk[8 * 3] = iclp[(x8 + x6) >> 14];blk[8 * 4] = iclp[(x8 - x6) >> 14];blk[8 * 5] = iclp[(x0 - x4) >> 14];blk[8 * 6] = iclp[(x3 - x2) >> 14];blk[8 * 7] = iclp[(x7 - x1) >> 14];
}

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