YUV转为RGB24及IplImage格式(I420和YV12)及Java版实现

mac2022-06-30 26

http://blog.csdn.net/xy365/article/details/18735849

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一、YUV简介一般来说，直接采集到的视频数据是RGB24的格式，RGB24一帧的大小size=width×heigth×3 Byte，RGB32的size=width×heigth×4 Byte，如果是I420（即YUV标准格式4：2：0）的数据量是 size=width×heigth×1.5 Byte。在采集到RGB24数据后，需要对这个格式的数据进行第一次压缩。即将图像的颜色空间由RGB24转化为IYUV。因为，X264在进行编码的时候需要标准的YUV（4：2：0）。但是这里需要注意的是，虽然YV12也是（4：2：0），但是YV12和I420的却是不同的，在存储空间上面有些区别。如下： YV12 ：亮度（行×列） + V（行×列/4) + U（行×列/4） I420 ：亮度（行×列） + U（行×列/4) + V（行×列/4）可以看出，YV12和I420基本上是一样的，就是UV的顺序不同。 YUV420p 和 YUV420的区别在于存储格式上有区别： YUV420p：yyyyyyyy uuuu vvvvv YUV420： yuv yuv yuv 关于YUV 更详细资料可参考：http://zh.wikipedia.org/wiki/YUV。另外，需要注意的是海康设备回调数据类型为YV12格式；而大华设备回调数据类型为YUV420格式。

二、YUV420转IplImage

采用OpenCV转换的方式，代码如下：

IplImage* YUV420_To_IplImage_Opencv(unsigned char* pYUV420, int width, int height) { if (!pYUV420) { return NULL; } IplImage *yuvimage,*rgbimg,*yimg,*uimg,*vimg,*uuimg,*vvimg; int nWidth = width; int nHeight = height; rgbimg = cvCreateImage(cvSize(nWidth, nHeight),IPL_DEPTH_8U,3); yuvimage = cvCreateImage(cvSize(nWidth, nHeight),IPL_DEPTH_8U,3); yimg = cvCreateImageHeader(cvSize(nWidth, nHeight),IPL_DEPTH_8U,1); uimg = cvCreateImageHeader(cvSize(nWidth/2, nHeight/2),IPL_DEPTH_8U,1); vimg = cvCreateImageHeader(cvSize(nWidth/2, nHeight/2),IPL_DEPTH_8U,1); uuimg = cvCreateImage(cvSize(nWidth, nHeight),IPL_DEPTH_8U,1); vvimg = cvCreateImage(cvSize(nWidth, nHeight),IPL_DEPTH_8U,1); cvSetData(yimg,pYUV420, nWidth); cvSetData(uimg,pYUV420+nWidth*nHeight, nWidth/2); cvSetData(vimg,pYUV420+long(nWidth*nHeight*1.25), nWidth/2); cvResize(uimg,uuimg,CV_INTER_LINEAR); cvResize(vimg,vvimg,CV_INTER_LINEAR); cvMerge(yimg,uuimg,vvimg,NULL,yuvimage); cvCvtColor(yuvimage,rgbimg,CV_YCrCb2RGB); cvReleaseImage(&uuimg); cvReleaseImage(&vvimg); cvReleaseImageHeader(&yimg); cvReleaseImageHeader(&uimg); cvReleaseImageHeader(&vimg); cvReleaseImage(&yuvimage); if (!rgbimg) { return NULL; } return rgbimg; }

采用数学转换的方式，代码如下：

bool YUV420_To_BGR24(unsigned char *puc_y, unsigned char *puc_u, unsigned char *puc_v, unsigned char *puc_rgb, int width_y, int height_y) { if (!puc_y || !puc_u || !puc_v || !puc_rgb) { return false; } //初始化变量 int baseSize = width_y * height_y; int rgbSize = baseSize * 3; BYTE* rgbData = new BYTE[rgbSize]; memset(rgbData, 0, rgbSize); /* 变量声明 */ int temp = 0; BYTE* rData = rgbData; //r分量地址 BYTE* gData = rgbData + baseSize; //g分量地址 BYTE* bData = gData + baseSize; //b分量地址 int uvIndex =0, yIndex =0; //YUV->RGB 的转换矩阵 //double Yuv2Rgb[3][3] = {1, 0, 1.4022, // 1, -0.3456, -0.7145, // 1, 1.771, 0}; for(int y=0; y < height_y; y++) { for(int x=0; x < width_y; x++) { uvIndex = (y>>1) * (width_y>>1) + (x>>1); yIndex = y * width_y + x; /* r分量 */ temp = (int)(puc_y[yIndex] + (puc_v[uvIndex] - 128) * 1.4022); rData[yIndex] = temp<0 ? 0 : (temp > 255 ? 255 : temp); /* g分量 */ temp = (int)(puc_y[yIndex] + (puc_u[uvIndex] - 128) * (-0.3456) + (puc_v[uvIndex] - 128) * (-0.7145)); gData[yIndex] = temp < 0 ? 0 : (temp > 255 ? 255 : temp); /* b分量 */ temp = (int)(puc_y[yIndex] + (puc_u[uvIndex] - 128) * 1.771); bData[yIndex] = temp < 0 ? 0 : (temp > 255 ? 255 : temp); } } //将R,G,B三个分量赋给img_data int widthStep = width_y*3; for (int y = 0; y < height_y; y++) { for (int x = 0; x < width_y; x++) { puc_rgb[y * widthStep + x * 3 + 2] = rData[y * width_y + x]; //R puc_rgb[y * widthStep + x * 3 + 1] = gData[y * width_y + x]; //G puc_rgb[y * widthStep + x * 3 + 0] = bData[y * width_y + x]; //B } } if (!puc_rgb) { return false; } delete [] rgbData; return true; } IplImage* YUV420_To_IplImage(unsigned char* pYUV420, int width, int height) { if (!pYUV420) { return NULL; } //初始化变量 int baseSize = width*height; int imgSize = baseSize*3; BYTE* pRGB24 = new BYTE[imgSize]; memset(pRGB24, 0, imgSize); /* 变量声明 */ int temp = 0; BYTE* yData = pYUV420; //y分量地址 BYTE* uData = pYUV420 + baseSize; //u分量地址 BYTE* vData = uData + (baseSize>>2); //v分量地址 if(YUV420_To_BGR24(yData, uData, vData, pRGB24, width, height) == false || !pRGB24) { return NULL; } IplImage *image = cvCreateImage(cvSize(width, height), 8,3); memcpy(image->imageData, pRGB24, imgSize); if (!image) { return NULL; } delete [] pRGB24; return image; }

三、YV12转IplImage

//YV12转为BGR24数据 bool YV12_To_BGR24(unsigned char* pYV12, unsigned char* pRGB24,int width, int height) { if(!pYV12 || !pRGB24) { return false; } const long nYLen = long(height * width); const int halfWidth = (width>>1); if(nYLen<1 || halfWidth<1) { return false; } // yv12's data structure // |WIDTH | // y......y-------- // y......y HEIGHT // y......y // y......y-------- // v..v // v..v // u..u // u..u unsigned char* yData = pYV12; unsigned char* vData = &yData[nYLen]; unsigned char* uData = &vData[nYLen>>2]; if(!uData || !vData) { return false; } // Convert YV12 to RGB24 int rgb[3]; int i, j, m, n, x, y; m = -width; n = -halfWidth; for(y=0; y<height;y++) { m += width; if(!(y % 2)) n += halfWidth; for(x=0; x<width;x++) { i = m + x; j = n + (x>>1); rgb[2] = int(yData[i] + 1.370705 * (vData[j] - 128)); // r rgb[1] = int(yData[i] - 0.698001 * (uData[j] - 128) - 0.703125 * (vData[j] - 128)); // g rgb[0] = int(yData[i] + 1.732446 * (uData[j] - 128)); // b //j = nYLen - iWidth - m + x; //i = (j<<1) + j; //图像是上下颠倒的 j = m + x; i = (j<<1) + j; for(j=0; j<3; j++) { if(rgb[j]>=0 && rgb[j]<=255) pRGB24[i + j] = rgb[j]; else pRGB24[i + j] = (rgb[j] < 0)? 0 : 255; } } } if (pRGB24 == NULL) { return false; } return true; } IplImage* YV12_To_IplImage(unsigned char* pYV12, int width, int height) { if (!pYV12) { return NULL; } int sizeRGB = width* height *3; unsigned char* pRGB24 = new unsigned char[sizeRGB]; memset(pRGB24, 0, sizeRGB); if(YV12_To_BGR24(pYV12, pRGB24 ,width, height) == false || (!pRGB24)) { return NULL; } IplImage* pImage = cvCreateImage(cvSize(width, height), 8, 3); if(!pImage) { return NULL; } memcpy(pImage->imageData, pRGB24, sizeRGB); if (!(pImage->imageData)) { return NULL; } delete [] pRGB24; return pImage; }

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参考以上代码，实现了Java版（注意无符号数及指针的处理）

// YV12格式一个像素占1.5个字节 private byte[] YV12_To_RGB24( byte[] yv12, int width, int height) { if(yv12 == null) { return null; } int nYLen = ( int)width * height; int halfWidth = width >> 1; if(nYLen<1 || halfWidth<1) { return null; } // yv12's data structure // |WIDTH | // y......y-------- // y......y HEIGHT // y......y // y......y-------- // v..v // v..v // u..u // u..u // Convert YV12 to RGB24 byte[] rgb24 = new byte[width * height * 3]; int[] rgb = new int[3]; int i, j, m, n, x, y; m = -width; n = -halfWidth; for(y=0; y<height; y++) { m += width; if(y%2 != 0) { n += halfWidth; } for(x=0; x<width; x++) { i = m+x; j = n + (x>>1); rgb[2] = ( int)(( int)(yv12[i]&0xFF) + 1.370705 * (( int)(yv12[nYLen+j]&0xFF) - 128)); // r rgb[1] = ( int)(( int)(yv12[i]&0xFF) - 0.698001 * (( int)(yv12[nYLen+(nYLen>>2)+j]&0xFF) - 128) - 0.703125 * (( int)(yv12[nYLen+j]&0xFF) - 128)); // g rgb[0] = ( int)(( int)(yv12[i]&0xFF) + 1.732446 * (( int)(yv12[nYLen+(nYLen>>2)+j]&0xFF) - 128)); // b // j = nYLen - iWidth - m + x; // i = (j<<1) + j; // 图像是上下颠倒的 j = m + x; i = (j<<1) + j; for(j=0; j<3; j++) { if(rgb[j]>=0 && rgb[j]<=255) { rgb24[i+j] = ( byte)rgb[j]; } else { rgb24[i+j] = ( byte) ((rgb[j] < 0)? 0 : 255); } } } } return rgb24; } private IplImage YV12_ToIplImage( byte[] yv12, int width, int height) { if(yv12 == null) { return null; } byte[] rgb24 = YV12_To_RGB24(yv12, width, height); if(rgb24 == null) { return null; } IplImage image = cvCreateImage(cvSize(width, height), 8, 3); image.imageData( new BytePointer(rgb24)); return image; }

转载于:https://www.cnblogs.com/cuizhf/p/3722471.html

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