YV12转RGB24的计算转换和bmp（dib）文件的显示保存

#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HBITMAP

bool 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 &lt; height;i++){
    for (int j = 0;j &lt; 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 &lt; 3;k++){
            idx = (i * width + j) * 3 + k;
            if(bgr[k] &gt;= 0 &amp;&amp; bgr[k] &lt;= 255)
                pBGR24[idx] = bgr[k];
            else
                pBGR24[idx] = (bgr[k] &lt; 0)?0:255;
        }
    }
}
return true;

}