搗鼓了半天，好不容易成功，先記錄核心程式碼，後面詳細整理。

//YUV 轉 Mat
              Mat mat = new Mat(1440*3/2,1080,CvType.CV_8UC1);//,byteBuffer 1440,1080
              int re =  mat.put(0,0,data);
              Mat bgr_i420 = new Mat();
              Imgproc.cvtColor(mat , bgr_i420, Imgproc.COLOR_YUV2BGR_NV21);//COLOR_YUV2BGR_I420

//jpeg 轉 Mat
Mat mat = Imgcodecs.imdecode(new MatOfByte(jpegData), Imgcodecs.CV_LOAD_IMAGE_UNCHANGED);