android视频采集YUV420旋转角度算法

红太狼 2022-06-15 07:48 266阅读 0赞

常用的YUV420旋转角度算法，选择90度的算法已经优化过了。网上也很多，不过有一些不能用，这些是本人亲测过的。有一点需要注意。如果你需要旋转90度或者270度，那么需要把宽和高对调。否则会花屏。因为比如你320 X 240，图像旋转90°之后宽高变成了240 X 320。

//顺时针旋转270度
        private void YUV420spRotate270(byte[] des, byte[] src, int width, int height) {
            int n = 0;
            int uvHeight = height >> 1;
            int wh = width * height;
            //copy y
            for (int j = width - 1; j >= 0; j--) {
                for (int i = 0; i < height; i++) {
                    des[n++] = src[width * i + j];
                }
            }
    
            for (int j = width - 1; j > 0; j -= 2) {
                for (int i = 0; i < uvHeight; i++) {
                    des[n++] = src[wh + width * i + j - 1];
                    des[n++] = src[wh + width * i + j];
                }
            }
        }
    
        //旋转180度（顺时逆时结果是一样的）
        private void YUV420spRotate180(byte[] src, byte[] des, int width, int height) {
    
            int n = 0;
            int uh = height >> 1;
            int wh = width * height;
            //copy y
            for (int j = height - 1; j >= 0; j--) {
                for (int i = width - 1; i >= 0; i--) {
                    des[n++] = src[width * j + i];
                }
            }
    
    
            for (int j = uh - 1; j >= 0; j--) {
                for (int i = width - 1; i > 0; i -= 2) {
                    des[n] = src[wh + width * j + i - 1];
                    des[n + 1] = src[wh + width * j + i];
                    n += 2;
                }
            }
        }
    
        //顺时针旋转90
        private void YUV420spRotate90Clockwise(byte[] src, byte[] dst, int srcWidth, int srcHeight) {
    //        int wh = width * height;
    //        int k = 0;
    //        for (int i = 0; i < width; i++) {
    //            for (int j = height - 1; j >= 0; j--) {
    //                des[k] = src[width * j + i];
    //                k++;
    //            }
    //        }
    //        for (int i = 0; i < width; i += 2) {
    //            for (int j = height / 2 - 1; j >= 0; j--) {
    //                des[k] = src[wh + width * j + i];
    //                des[k + 1] = src[wh + width * j + i + 1];
    //                k += 2;
    //            }
    //        }
    
            int wh = srcWidth * srcHeight;
            int uvHeight = srcHeight >> 1;
    
            //旋转Y
            int k = 0;
            for (int i = 0; i < srcWidth; i++) {
                int nPos = 0;
                for (int j = 0; j < srcHeight; j++) {
                    dst[k] = src[nPos + i];
                    k++;
                    nPos += srcWidth;
                }
            }
    
            for (int i = 0; i < srcWidth; i += 2) {
                int nPos = wh;
                for (int j = 0; j < uvHeight; j++) {
                    dst[k] = src[nPos + i];
                    dst[k + 1] = src[nPos + i + 1];
                    k += 2;
                    nPos += srcWidth;
                }
            }
    
        }
    
        //逆时针旋转90
        private void YUV420spRotate90Anticlockwise(byte[] src, byte[] dst, int width, int height) {
            int wh = width * height;
            int uvHeight = height >> 1;
    
            //旋转Y
            int k = 0;
            for (int i = 0; i < width; i++) {
                int nPos = width - 1;
                for (int j = 0; j < height; j++) {
                    dst[k] = src[nPos - i];
                    k++;
                    nPos += width;
                }
            }
    
            for (int i = 0; i < width; i += 2) {
                int nPos = wh + width - 1;
                for (int j = 0; j < uvHeight; j++) {
                    dst[k] = src[nPos - i - 1];
                    dst[k + 1] = src[nPos - i];
                    k += 2;
                    nPos += width;
                }
            }
    
            //不进行镜像翻转
    //        for (int i = 0; i < width; i++) {
    //            int nPos = width - 1;
    //            for (int j = 0; j < height; j++) {
    //                dst[k] = src[nPos - i];
    //                k++;
    //                nPos += width;
    //            }
    //        }
    //        for (int i = 0; i < width; i += 2) {
    //            int nPos = wh + width - 2;
    //            for (int j = 0; j < uvHeight; j++) {
    //                dst[k] = src[nPos - i];
    //                dst[k + 1] = src[nPos - i + 1];
    //                k += 2;
    //                nPos += width;
    //            }
    //        }
    
        }
    
        //镜像
        private void Mirror(byte[] yuv_temp, int w, int h) {
            int i, j;
    
            int a, b;
            byte temp;
            //mirror y
            for (i = 0; i < h; i++) {
                a = i * w;
                b = (i + 1) * w - 1;
                while (a < b) {
                    temp = yuv_temp[a];
                    yuv_temp[a] = yuv_temp[b];
                    yuv_temp[b] = temp;
                    a++;
                    b--;
                }
            }
            //mirror u
            int uindex = w * h;
            for (i = 0; i < h / 2; i++) {
                a = i * w / 2;
                b = (i + 1) * w / 2 - 1;
                while (a < b) {
                    temp = yuv_temp[a + uindex];
                    yuv_temp[a + uindex] = yuv_temp[b + uindex];
                    yuv_temp[b + uindex] = temp;
                    a++;
                    b--;
                }
            }
            //mirror v
            uindex = w * h / 4 * 5;
            for (i = 0; i < h / 2; i++) {
                a = i * w / 2;
                b = (i + 1) * w / 2 - 1;
                while (a < b) {
                    temp = yuv_temp[a + uindex];
                    yuv_temp[a + uindex] = yuv_temp[b + uindex];
                    yuv_temp[b + uindex] = temp;
                    a++;
                    b--;
                }
            }
        }