项目中用到,用来对YUV数据(图片的yuv或者视频单帧yuv数据)进行裁剪。
格式介绍:http://blog.csdn.net/vblittleboy/article/details/10945143
import android.graphics.RectF; import android.util.Log; /** * 用来裁剪yuv图像 * @author willhua * */ public class YuvCroper { private static String LOG_TAG = "VideoCrop"; public static int YUV_420SP = 0; //也即NV12 YYY...UVUVUV... public static int YUV_420P = 1; //也即I420 YYY...UUU...VVV... private final int mType; private byte[] mData; private final int mWidth; private final int mHeight; private final int mYLenght; private final int mCropLeft; private final int mCropTop; private int mCropWidth; private int mCropHeight; /** * * @param type yuv数据类型:YUV_SP() YUV_420P() * @param width yuv数据的原始宽度 * @param height yuv数据的原始高度 * @param crop 裁剪的区域。比如(0.25,0,1,0.85),每个值都在0-1之间 * @throws Exception */ public YuvCroper(int type, int width, int height, RectF crop) throws Exception{ if(width <= 0 || height <= 0 || crop == null || crop.width() <= 0 || crop.height() <= 0){ throw new Exception("ViewCrop:Wrong param! size:" + width + "*" + height + ". Crop:"+ crop); } mType = type; mWidth = width; mHeight = height; mYLenght = mWidth * mHeight; mCropHeight = (int)(crop.height() * mHeight); mCropWidth = (int)(crop.width() * mWidth); mCropHeight = roundTo16(mCropHeight, mHeight); mCropWidth = roundTo16(mCropWidth, mWidth); mCropLeft = (int)(crop.left * mWidth) / 16 * 16; mCropTop = (int)(crop.top * mHeight) / 16 * 16; mData = new byte[mCropHeight * mCropWidth * 3 / 2]; Log.d(LOG_TAG, "crop point:" + mCropLeft + "*" + mCropTop + " size:" + mCropWidth + "*" + mCropHeight); } /** * 单帧yuv数据 * @param oriData * @return */ public byte[] crop(byte[] oriData){ if(oriData == null || oriData.length != mYLenght * 3 / 2){ Log.d(LOG_TAG, "crop:wrong oriData!!!"); return mData; } if(mType == YUV_420SP){ processYuvsp(oriData); }else if(mType == YUV_420P){ processYuv420p(oriData); } return mData; } private void processYuvsp(byte[] oriData){ //copy y; int index = 0; int start = mCropLeft + mWidth * mCropTop; int end = mWidth * (mCropTop + mCropHeight); int oriStep = mWidth; int newstep = mCropWidth; index = copy(oriData, start, end, oriStep, newstep, index); //copy uv start = mYLenght + mWidth * mCropTop / 2 + mCropLeft; end = mYLenght + mWidth * (mCropTop + mCropHeight) / 2; oriStep = mWidth; newstep = mCropWidth; copy(oriData, start, end, oriStep, newstep, index); } private void processYuv420p(byte[] oriData){ int index = 0; int start = mCropLeft + mCropTop * mWidth; int end = mWidth * (mCropTop + mCropHeight); int oriStep = mWidth; int newstep = mCropWidth; //copy y; index = copy(oriData, start, end, oriStep, newstep, index); //copy u start = mYLenght + (mWidth * mCropTop / 4 + mCropLeft / 2) ; end = mYLenght + mWidth * (mCropTop + mCropHeight) / 4; oriStep = mWidth / 2; newstep = mCropWidth / 2; index = copy(oriData, start, end, oriStep, newstep, index); //copy v start = mYLenght / 4 * 5 + mWidth * mCropTop / 4 + mCropLeft / 2; end = mYLenght / 4 * 5 + mWidth * (mCropTop + mCropHeight) / 4; copy(oriData, start, end, oriStep, newstep, index); } private int copy(byte[] oriData, int start, int end, int oriStep, int newstep, int index){ for(int i = start; i < end; i += oriStep){ System.arraycopy(oriData, i, mData, index, newstep); index += newstep; } return index; } /** * 对于高通或者MTK平台,只支持宽高为16的整数备的数据 * @param size * @param limit * @return */ private int roundTo16(int size, int limit){ if(size >= limit){ return limit; } float f = size / 16f; int m; if(f - (int)f > 0.5f){ m = ((int)(f + 0.5)) * 16; }else{ m = (int)f * 16; } return m < 16 ? 16 : m; } }