private Camera.Parameters getDefaultCameraParameters() {
        Camera.Parameters parameters = camera.getParameters();
        if (defaultParameters == null) {
            defaultParameters = parameters.flatten();
        } else {
            parameters.unflatten(defaultParameters);
        }
        return parameters;
    }
@return the camera rotation relative to display rotation, in degrees. Typically 0 if the
   display is in landscape orientation.
zxing-android-embedded/src/com/journeyapps/barcodescanner/camera/CameraManager.java