Framing VideoOutput item in Qt QML

Question

I am using a VideoOutput item, which I have placed inside a Rectangle. This VideoOutput goes on top of the Rectangle, of its border and its rounded corners.

  Rectangle{
    radius: 12
    width: 200
    height: width
    border.color: black
    border.width: 15

    VideoOutput {
      fillMode: VideoOutput.PreserveAspectCrop
      anchors.fill: parent
      source: myCamera
      autoOrientation: true
    }
  }

  Camera {
    id: myCamera
    focus {
      focusMode: CameraFocus.FocusContinuous
      focusPointMode: CameraFocus.FocusPointAuto
    }
    captureMode: Camera.CaptureViewfinder
  }

I intentionaly made the border thick so it really shows what is going on. The border is hidden by the VideoOutput, and the rounded corners are ignored.

I can imagine that the VideoOutput item would use some acceleration tricks, so it might not play well with standard QML item behaviour. But is there a way get this to work, without adding a filter element, or is this the expected behaviour?