Error taking and saving .dng picture using the Camera2 API

Question

I'm creating an app that takes pictures in .dng format in order to process them. I'm using the camera2 API. I was able to take pictures and save them into my smartphone Android 13, but in .jpg format. But when I change my code in order to save them with .dng extension, I get an error.

The part of my code that takes and saves the picture is as follows:

Size largest = choosePictureSize(map.getOutputSizes(ImageFormat.RAW_SENSOR));
mImageReader = ImageReader.newInstance(largest.getWidth(), largest.getHeight(),
ImageFormat.RAW_SENSOR, /*maxImages*/1);
mImageReader.setOnImageAvailableListener(mOnImageAvailableListener, mBackgroundHandler);

private String getPictureFilePath(Context context) {
        final File dir = context.getExternalFilesDir(null);
        return (dir == null ? "" : (dir.getAbsolutePath() + "/"))
                + System.currentTimeMillis() + ".dng";
    }

Listener:

case ImageFormat.RAW_SENSOR: {
                    DngCreator dngCreator = new DngCreator(mCameraCharacteristics, mCaptureResult);
                    FileOutputStream output = null;
                    try {
                        output = new FileOutputStream(mFile);
                        dngCreator.writeImage(output, mImage);
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                        mImage.close();
                        if (null != output) {
                            try {
                                output.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                    }
                    break;
                }

@Override
        public void onCaptureProgressed(@NonNull CameraCaptureSession session,
                                        @NonNull CaptureRequest request,
                                        @NonNull CaptureResult partialResult) {
            process(partialResult);
        }

        @Override
        public void onCaptureCompleted(@NonNull CameraCaptureSession session,
                                       @NonNull CaptureRequest request,
                                       @NonNull TotalCaptureResult result) {
            process(result);
        }

I'm having this error:

java.lang.IllegalArgumentException: Null argument to DngCreator constructor

Answer 1

Based on the error message, either mCameraCharacteristics or mCaptureResult is null. Maybe you're clearing one of them before your callback has a chance to run?