android - 将 Flutter Frame Camera 转换为 android Bitmap

Question

我正在使用颤振插件相机（https://pub.dev/packages/camera）为 android 和 ios 开发颤振插件，所以首先我使用这种方法从插件流式传输帧：

controller.startImageStream((CameraImage img) {
     runlOnFrame(
                bytesList: img.planes.map((plane) {
                  return plane.bytes;
                }).toList(),
                imageHeight: img.height,
                imageWidth: img.width,
              )
}

runlOnFrame 方法是用 java 开发的，它可以将 YUV 字节转换为 RGBA 格式的位图，如下所示：

获取参数函数：

getArgs(HashMap args){
     List<byte[]> bytesList = (ArrayList) args.get("bytesList");
     int imageHeight = (int) (args.get("imageHeight"));
     int imageWidth = (int) (args.get("imageWidth"));
}

runOnFrame(List<byte[]> bytesList, int imageHeight, int imageWidth, ) throws IOException {
    int rotation = 90;
    ByteBuffer Y = ByteBuffer.wrap(bytesList.get(0));
    ByteBuffer U = ByteBuffer.wrap(bytesList.get(1));
    ByteBuffer V = ByteBuffer.wrap(bytesList.get(2));

    int Yb = Y.remaining();
    int Ub = U.remaining();
    int Vb = V.remaining();

    byte[] data = new byte[Yb + Ub + Vb];

    Y.get(data, 0, Yb);
    V.get(data, Yb, Vb);
    U.get(data, Yb + Vb, Ub);

    Bitmap bitmapRaw = Bitmap.createBitmap(imageWidth, imageHeight, Bitmap.Config.ARGB_8888);
    Allocation bmData = renderScriptNV21ToRGBA888(
        mRegistrar.context(),
        imageWidth,
        imageHeight,
        data);
    bmData.copyTo(bitmapRaw);

    Matrix matrix = new Matrix();
    matrix.postRotate(rotation);
    Bitmap finalbitmapRaw = Bitmap.createBitmap(bitmapRaw, 0, 0, bitmapRaw.getWidth(), bitmapRaw.getHeight(), matrix, true);
    saveBitm(finalbitmapRaw); // Function to save converted bitmap

  } 

  public Allocation renderScriptNV21ToRGBA888(Context context, int width, int height, byte[] nv21) {
    // https://stackoverflow.com/a/36409748
    RenderScript rs = RenderScript.create(context);
    ScriptIntrinsicYuvToRGB yuvToRgbIntrinsic = ScriptIntrinsicYuvToRGB.create(rs, Element.U8_4(rs));

    Type.Builder yuvType = new Type.Builder(rs, Element.U8(rs)).setX(nv21.length);
    Allocation in = Allocation.createTyped(rs, yuvType.create(), Allocation.USAGE_SCRIPT);

    Type.Builder rgbaType = new Type.Builder(rs, Element.RGBA_8888(rs)).setX(width).setY(height);
    Allocation out = Allocation.createTyped(rs, rgbaType.create(), Allocation.USAGE_SCRIPT);

    in.copyFrom(nv21);

    yuvToRgbIntrinsic.setInput(in);
    yuvToRgbIntrinsic.forEach(out);
    return out;
  }

问题是我得到这样的绿色位图图像：

https://imgur.com/2Gcgcc9

https://imgur.com/2Gcgcc9

标签： androidflutterdartandroid-cameraflutter-plugin