Betty有一个很棒的灵活抽象层，用于表示可以与NIO一起运行的读写缓冲区。在Netty 4中，这是ByteBuf类，在Netty 3中，这是ChannelBuffer。
我正在处理一个库（JDBC），它为一段数据返回一个InputStream，作为内部存储引擎的一部分。当前代码将此副本复制到中间字节数组，并在将此字节数组提供给Netty进行处理之前构建ChannelBuffer。我正在尝试减少在此堆栈中发生的不必要的副本的数量，并且希望将InputStream直接传递给Netty而不使用中间副本，以便Netty可以将InputStream的内容直接写入套接字而无需分配任何大型中间对象。 Netty中是否有任何工具允许从不调用数据集完整副本的InputStream创建只读ChannelBuffer / ByteBuf？
答案 0 :(得分：1)
您所寻找的可能是 //--------------Compute for calibration-------------------
N = n_boards*n;
objectPoints.resize(N);
for( i = 0; i < ny; i++ )
for(j = 0; j < nx; j++ ) objectPoints[i*nx + j] = cvPoint3D32f(i*squareSize, j*squareSize, 0);
for( i = 1; i < n_boards; i++ ) copy( objectPoints.begin(), objectPoints.begin() + n, objectPoints.begin() + i*n );
npoints.resize(n_boards,n);
CvMat _objectPoints = cvMat(1, N, CV_32FC3, &objectPoints[0] );
CvMat _imagePoints1 = cvMat(1, N, CV_32FC2, &points[0][0] );
CvMat _imagePoints2 = cvMat(1, N, CV_32FC2, &points[1][0] );
CvMat _npoints = cvMat(1, npoints.size(), CV_32S, &npoints[0] );
cvSetIdentity(&_M1calib);
cvSetIdentity(&_M2calib);
cvZero(&_D1);
cvZero(&_D2);
printf("\nRunning stereo calibration ...");
fflush(stdout);
cvStereoCalibrate( &_objectPoints, &_imagePoints1, &_imagePoints2, &_npoints,&_M1calib, &_D1, &_M2calib, &_D2,imageSize, &_R, &_Tcalib, &_E, &_F,
cvTermCriteria(CV_TERMCRIT_ITER+CV_TERMCRIT_EPS, 100, 1e-5),
CV_CALIB_FIX_ASPECT_RATIO+CV_CALIB_ZERO_TANGENT_DIST + CV_CALIB_SAME_FOCAL_LENGTH );
printf("\nDone Calibration");
cvUndistortPoints( &_imagePoints1, &_imagePoints1,&_M1calib, &_D1, 0, &_M1calib );
cvUndistortPoints( &_imagePoints2, &_imagePoints2,&_M2calib, &_D2, 0, &_M2calib );
CvMat* mx1calib = cvCreateMat( imageSize.height,imageSize.width, CV_32F );
CvMat* my1calib = cvCreateMat( imageSize.height,imageSize.width, CV_32F );
CvMat* mx2calib = cvCreateMat( imageSize.height,imageSize.width, CV_32F );
CvMat* my2calib = cvCreateMat( imageSize.height,imageSize.width, CV_32F );
double R1[3][3], R2[3][3], P1[3][4], P2[3][4];
CvMat _R1 = cvMat(3, 3, CV_64F, R1);
CvMat _R2 = cvMat(3, 3, CV_64F, R2);
CvMat _P1 = cvMat(3, 4, CV_64F, P1);
CvMat _P2 = cvMat(3, 4, CV_64F, P2);
cvStereoRectify( &_M1calib, &_M2calib, &_D1, &_D2, imageSize,&_R, &_Tcalib,&_R1, &_R2, &_P1, &_P2, &_Qcalib,0/*CV_CALIB_ZERO_DISPARITY*/ );
cvInitUndistortRectifyMap(&_M1calib,&_D1,&_R1,&_P1,mx1calib,my1calib);
cvInitUndistortRectifyMap(&_M2calib,&_D2,&_R2,&_P2,mx2calib,my2calib);
和ChunkedWriteHandler？