Java yuv422To420

 public static byte[] yuv422To420(byte[] yuv422, int width, int height) {
        int len = width * height;
        //yuv格式数组大小，y亮度占len长度，u,v各占len/4长度。
        byte[] yuv = new byte[len * 3 / 2];

        int y = 0;
        int u = len;

        int index_y = 0, index_u = 0;

        boolean is_u = true;

        for (int i = 0; i < height * 2; i++) {
            for (int j = 0; j < width; j = j + 4) {
                yuv[y + (index_y++)] = yuv422[width * i + j];
                yuv[y + (index_y++)] = yuv422[width * i + j + 2];
            }
        }

        for (int i = 0; i < height; i = i + 2) {
            int base = i * width * 2;
            for (int j = base + 1; j < base + width * 2; j = j + 2) {
                if (is_u) {
                    yuv[u + (index_u++)] = yuv422[j];
                    is_u = false;
                } else {
                    yuv[u + (index_u++)] = yuv422[j];
                    is_u = true;
                }

            }
        }

        return yuv;
    }