SetEnabled(false) is used to tell the deinterlacer to forget about the last frame in case low motion is used which needs two frames (current and previous). If you disable deinterlacing and start it again it would otherwise use a wrong or outdated previous frame. But one could also use a more sophisticated approach to pass also frame numbers and let the deinterlacer detect the gap. Also the entire buffer management could be improved that you can switch back and force between vpu/ipu. Currently if the ipu path is taken you cannot switch back to vpu for the same frame. This only affects toggling deinterlacing during pause.