Originally Posted by Kris Deering
Update on the frame dropping/stutter with Netflix. I tested the same movie with my OLED downstairs playing directly from my ATV4K. Same stutter. So it looks like Netflix is doing some kind of frame rate conversion (output is 23.976) or something else is going on. But Radiance doesn't look to be the culprit.
I've not tried that title, and I'm not sure if it is this issue you are seeing, but note that some Netflix content is 24.00p - which the AppleTV cannot output at native framerate - it has to output at 23.976p which means a dropped frame every 42s or so. It has a similar issue with 60p vs 59.94p, but 60p content is very uncommon.
There are some test streams in the Netflix library for all the rates that you can check - search "Test Patterns" from the search UI.
Some recent titles that are affected:
El Camino: A Breaking Bad Movie
Dolemite Is My Name
The Red Sea Diving Resort
Samsung UHD players do correctly switch to 24.00p output for the above, so if you have one of those then you can check the title in question and look at the output; if it switches to 24.00p then you know why the AppleTV is dropping frames.
Sony players also switch if configured to do so, but only for 23.976 vs 24p. Everything else is played back at 59.94p, including 25p (which is pretty tragic looking).
The only option if you have to use an AppleTV that minimizes the stutter is (rather counter intuitively) to disable rate matching. This converts 24.00p to 59.94p and your eye will usually lose the dropped frames necessary because the cadence is already ruined by the 3:2 pulldown that just occasionally changes to 2:2 for 24.00p content.
Unfortunately on the AppleTV even the Developer HUD won't accurately tell you the framerate for most streaming content so you have to try another player that is known to behave itself if you want to be sure this is the issue.