Record if additional software downscaling is needed for a particular stream in the RPi::Stream class. Additional software downscaling may be needed if the user required downscale factor is greater than what the ISP hardware is capable of. Signed-off-by: Naushir Patuck <naush@raspberrypi.com> Reviewed-by: David Plowman <david.plowman@raspberrypi.com> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>