There are lots of ways you can get film-on but they do not all give the same quality. I used a small Linux based PC connected to the router with ethernet, so high speed, and to the TV with HDMI. I selected the film-on web site on Firefox browser and then selected full screen. That produced tearing especially on panning shots.
Friends who use the film-on app on an ipad and mirror that to the TV using WiFi get a much better picture despite having a much slower broadband connection. I have also tried the film-on app on an Android smart phone mirrored with WiFi to a smart TV and that also gave a good picture. It looks like the apps access a less compressed video stream than the web browser stream. You can also pay a fee and get a higher resolution stream but if you are prepared to pay a monthly fee I would also consider ex patvision.