YV12转RGB24的计算转换和bmp（dib）文件的显示保存

最近又接触到图像处理这一块，翻查到一年前自己写的代码http://blog.csdn.net/gongluck93/article/details/52813042，发现有点看不懂了！

所以自己又整理了一波（YV12转RGB24，显示和保存dib）：

#include "stdafx.h"/******************************************************************* *  Copyright(c) 2017 *  All rights reserved. * *  文件名称: Bmp.cpp *  简要描述: bmp位图相关处理 * *  创建日期: 2017-08-04 *  作者:  gongluck *  说明: * *  修改日期: *  作者:  *  说明: ******************************************************************/#include "Bmp.h"//根据文件头和dib数据保存bmp文件bool SaveBmpWithFileInfo(const char* filename,const BITMAPFILEHEADER* fileheader,const BITMAPINFO* bmpinfo,const void* bits){    FILE* fp = NULL;    if(filename == NULL || fileheader == NULL || bmpinfo == NULL || bits == NULL)        return false;    if((fp = fopen(filename,"wb")) == NULL)        return false;    fwrite(fileheader,sizeof(BITMAPFILEHEADER),1,fp);    fwrite(bmpinfo,sizeof(BITMAPINFO),1,fp);    fwrite(bits,bmpinfo->bmiHeader.biSizeImage,1,fp);    fclose(fp);    return true;}//根据位深度、像素宽、像素高和dib数据保存bmp文件//深度24以下的不能处理（没有考虑有调色板的情况）bool SaveBmpWithBitscountAndWH(const char* filename,int nBits,int width,int height,const void* bits){    BITMAPFILEHEADER header = {0};    BITMAPINFO info = {0};    info.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);    info.bmiHeader.biWidth = width;    info.bmiHeader.biHeight = -height;    info.bmiHeader.biPlanes = 1;    info.bmiHeader.biBitCount = nBits;    info.bmiHeader.biCompression = BI_RGB;    info.bmiHeader.biSizeImage = (width * nBits + 31) / 32 * 4 * height;    header.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFO) + info.bmiHeader.biSizeImage;    header.bfType = 0x4d42;//"BM"    header.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFO);    return SaveBmpWithFileInfo(filename,&header,&info,bits);}//由位图句柄（HBITMAP）保存成bmp图片//可以用CreateDIBitmap、CreateDIBSection等函数获取HBITMAPbool SavePicture(HBITMAP hbitmap,const char* filepath){      HDC hdc= GetDC(NULL);      BITMAP bitmap = {0};      WORD clrbits = 0;      BITMAPINFO* bitmapinfo = NULL;      BITMAPFILEHEADER fileheader;      DWORD temp;      void* buf = NULL;      FILE* fp = NULL;      GetObject(hbitmap,sizeof(BITMAP),&bitmap);      clrbits = bitmap.bmBitsPixel * bitmap.bmPlanes;//每点的颜色位数*平面数      if(clrbits == 1) ;      else if(clrbits <= 4) clrbits = 4;      else if(clrbits <= 8) clrbits = 8;      else if(clrbits <= 16) clrbits = 16;      else if(clrbits <= 24) clrbits = 24;      else clrbits = 32;      if(clrbits < 24)//24位以下需要调色板         bitmapinfo = (BITMAPINFO*)malloc(sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD)*(1<<clrbits));      else         bitmapinfo = (BITMAPINFO*)malloc(sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD));      bitmapinfo->bmiHeader.biBitCount = clrbits;//图像颜色位数      bitmapinfo->bmiHeader.biClrImportant = 0;      bitmapinfo->bmiHeader.biClrUsed = (clrbits<24) ? (1<<clrbits) : 0;//使用的颜色数      bitmapinfo->bmiHeader.biCompression = BI_RGB;//压缩方式,BI_RGB不压缩      bitmapinfo->bmiHeader.biHeight = bitmap.bmHeight;//位图高度      bitmapinfo->bmiHeader.biPlanes = bitmap.bmPlanes;//设备平面数      bitmapinfo->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);//BITMAPINFOHEADER结构体大小      bitmapinfo->bmiHeader.biSizeImage = (bitmap.bmWidth * clrbits + 31) / 32 * 4 * bitmap.bmHeight;//位图数据大小      bitmapinfo->bmiHeader.biWidth = bitmap.bmWidth;//位图宽度      bitmapinfo->bmiHeader.biXPelsPerMeter = bitmapinfo->bmiHeader.biYPelsPerMeter = 0;      fileheader.bfType = 0x4d42;      fileheader.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFO)         + sizeof(RGBQUAD)*(bitmapinfo->bmiHeader.biClrUsed==0 ? 0 : bitmapinfo->bmiHeader.biClrUsed)          + bitmapinfo->bmiHeader.biSizeImage;      fileheader.bfReserved1 = fileheader.bfReserved2 = 0;      fileheader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFO) +           sizeof(RGBQUAD)*(bitmapinfo->bmiHeader.biClrUsed==0 ? 0 : bitmapinfo->bmiHeader.biClrUsed);      buf = malloc(bitmapinfo->bmiHeader.biSizeImage);      GetDIBits(hdc,hbitmap,0,bitmap.bmHeight,buf,bitmapinfo,DIB_RGB_COLORS);    fp = fopen(filepath,"wb");      fwrite(&fileheader,sizeof(BITMAPFILEHEADER),1,fp);      fwrite(bitmapinfo,sizeof(BITMAPINFO),1,fp);      fwrite(buf,bitmapinfo->bmiHeader.biSizeImage,1,fp);      fclose(fp);      free(buf);    free(bitmapinfo);    ReleaseDC(NULL,hdc);      return true;}  //将YV12转BGR24，没有效率可言（推荐使用ffmpeg）bool YV12ToBGR24_Native(unsigned char* pYUV,unsigned char* pBGR24,int width,int height){    if (width < 1 || height < 1 || pYUV == NULL || pBGR24 == NULL)        return false;    const long len = width * height;    unsigned char* yData = pYUV;    unsigned char* vData = &yData[len];    unsigned char* uData = &vData[len >> 2];    int bgr[3];    int yIdx,uIdx,vIdx,idx;    for (int i = 0;i < height;i++){        for (int j = 0;j < width;j++){            yIdx = i * width + j;            vIdx = (i/2) * (width/2) + (j/2);            uIdx = vIdx;            bgr[0] = (int)(yData[yIdx] + 1.732446 * (uData[vIdx] - 128));                                    // b分量            bgr[1] = (int)(yData[yIdx] - 0.698001 * (uData[uIdx] - 128) - 0.703125 * (vData[vIdx] - 128));    // g分量            bgr[2] = (int)(yData[yIdx] + 1.370705 * (vData[uIdx] - 128));                                    // r分量            for (int k = 0;k < 3;k++){                idx = (i * width + j) * 3 + k;                if(bgr[k] >= 0 && bgr[k] <= 255)                    pBGR24[idx] = bgr[k];                else                    pBGR24[idx] = (bgr[k] < 0)?0:255;            }        }    }    return true;}

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