Aurich Lawson | Getty Images | Roku
Roku TV owners have been introduced to a number of annoyances recently through the software update pipeline. There was an arbitration-demanding terms of service that locked your TV until you agreed (or mailed a letter). There is the upcoming introduction of ads to the home screen. But the latest irritation hits some Roku owners right in the eyes.
Reports on Roku’s community forums and on Reddit find owners of TCL HDTVs, on which Roku is a built-in OS, experiencing “motion smoothing” without having turned it on after updating to Roku OS 13. Some people are reporting that their TV never offered “Action Smoothing” before, but it is now displaying the results with no way to turn it off. Neither the TV’s general settings, nor the specific settings available while content is playing, offer a way to turn it off, according to some users.
“Action smoothing” is Roku’s name for video interpolation, or motion smoothing. The heart of motion smoothing is Motion Estimation Motion Compensation (MEMC). Fast-moving video, such as live sports or intense action scenes, can have a “juddery” feeling when shown on TVs at a lower frame rate. Motion smoothing uses MEMC hardware and algorithms to artificially boost the frame rate of a video signal by creating its best guess of what a frame between two existing frames would look like and then inserting it to boost the frame rate.
When it works, a signal looks more fluid and, as the name implies, smooth. When it is left on and a more traditional signal at 24 or 30 frames per second is processed, it works somewhat too well. Shows and films look awkwardly realistic, essentially lacking the motion blur and softer movement to which we’re accustomed. Everything looks like a soap opera or like you’re watching a behind-the-scenes smartphone video of your show. It’s so persistent an issue, and often buried in a TV’s settings, that Tom Cruise did a whole PSA about it back in 2018.
Ars has contacted Roku for comment and will update this post with a response. When affected Roku TVs regain their ability to keep motion smoothing at bay, the setting is typically located in the “Expert Settings” area of the TV or by enabling “Movie” mode from the quick settings.