The new ATV 4k looks better in SDR. Significantly better. The whole interface is brighter, more responsive, better colors. And no dimming effect noticed with overlays. Solution: Step 1 - Set the ATV output to 4k SDR. Done. Awesome.
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I noticed something similar. Mine looks fine with 4k HDR but dimmed when i turn on 4k dolby vision. The 4k dolby vision looks good with netflix though.
Agree 100%. It’s ridiculous that the ATV 4K wants to output everything in HDR. Apple need to implement automatic resolution/framerate/HDR switching…I don’t care if it’s ‘inelegant’. I’ve set mine to 1080p SDR, and I manually switch to 4K HDR if I’m going to watch something in that format.
I like the way the UI looks in 4k SDR 60hz, and Channels standard HD content looks great still. I do manually switch output to 24hz when watching movies in other apps though, since this prevents the periodic motion judder that occurs when watching movies at 60hz. Major motion pictures are filmed at 24fps.
An automatic switch to 24hz for movies would be nice.
EDIT: I think the reason that Apple hasn’t implemented auto-switching is that not all TVs are compatible with the best possible output formats for each medium.
They use the EDID from the TV already to know what resolutions the TV supports, so that’s not the reason. Switching resolution always makes the screen go black with a delay, and Apple doesn’t like that, it doesn’t play well with their model of “it just works” when they’re reliant on the tv switching resolutions which can rarely cause issues and the tv won’t accept the input or show static with HDCP 2.2.
They also don’t like that their animations end up happening at 24fps when designed for 60fps. They look like crap.
But hey, let’s trade judder for better animations on the player controls UI.
The new ATV has a 24hz output option, I would guess its there because so many people who watch movies requested it. 120hz would be the best compromise to watch both frame rates without switching the output setting, but I don’t know if the ATV4k does this. I know my TV won’t do 4k at 120hz.
Manually switching is not a huge deal for me though, I don’t watch movies often enough for it to bother me. But having the output frame rate automatically switch to the frame rate of the source content would be a cool feature, even if it takes a second to switch.
Yup me too. I’m exhausted complaining about it at his point. At least we finally have a 24hz option. And I’m in the same boat about movies, I don’t warch enough for it to be a pain to switch so I’m just happy I can at all, heh.
Personally I set mine to 4K SDR. With a 1080p UI or video source the TV or the ATV will just pixel double anyway and I can’t tell the difference whichever does it. With 4K sources then I don’t have to switch. The only time I would have to switch is with a HDR source but my TV is worse in HDR than in SDR so I don’t bother (Samsung 60” Series 6 LCD).
From the tvOS 11.2 beta notes (below). Could this finally be the answer to our requests?! @tmm1 @maddox
Mode Switching
Notes
AVKit uses automatic frame rate and dynamic range switching for fullscreen video playback on Apple TV 4K under most circumstances. tvOS 11.2 adds APIs for these features for apps that don’t use AVKit for video playback. For information, see https:// developer.apple.com/fall17/503.
Still waiting on the documentation for AVDisplayCriteria to be published, but it sounds like this would let us force 50hz in the Channels video player (although perhaps only on the new 4K model).
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This was the first thing I thought of when I read this on macrumors. Lol. Here’s hoping! Good excuse to upgrade my Apple TV to 4K… then I guess a new 4K TV as well?? 
4k tvs are cheap. And 4k streaming is really awesome to look at. Everyone who watches movies should get one. If all you use is Channels, it works the same. It would be nice if there were 4k OTA broadcasts already, but I think they will come in 2019. But I’ve currently settled on the ATV 4k SDR 60hz setting for everything, which looks great in the USA. My wife is not going to bother manually switching resolutions. I would welcome the auto-switching to match native movie frame rates though.
Thank goodness Apple have come around to frame rate and range switching. 24Hz for movies and I can keep the SDR setting and only switch to HDR with HDR content.
Glad they have also done APIs for apps like Channels that use its own player rather than AVKit. On the subject of which - does Channels use AVKit for h264 and h265 and only use mplayer for mpeg2 or does it use mplayer for everything??
Any news of bitstream sound output in 11.2 to support Atmos? Also we all want the Dolby/DTS lights on our receivers to light up too rather than use PCM even though the quality is identicle!!
We use VideoToolbox to decode h264/hevc but playback is still via the custom player.
Unlikely to happen, since the ATV needs to decode the audio to add in any system sounds before outputting to the speakers. Bitstream pass-through would not allow for navigation and other system sounds effects.
Yes that was the reason for only outputting PCM with the XBO as well. However MS eventually had to add bitstream to support Atmos/DTS:X. It is a selectable option in the BluRay disc settings - streamed video isn’t supported.
I suspect Apple will too even though you will lose navigation sounds in fullscreen video. How many of us are going to miss a little beep when we press play/pause?? Games and the ATV UI can still output PCM so no issue there. PIP would be an issue but as this isn’t implemented on the ATV it isn’t.
Yes of course. Forgot you have to deinterlace it as well.
So will Channels be able to use the new APIs to set frame rate to 50Hz or 60Hz to match the broadcast frame rate?. I don’t know of any broadcasters that change frame rates to 24Hz for movies or whether this is even possible with ATSC or DVB. If it is perhaps (I hope) it’s only a matter of time before broadcasters just broadcast in the original framerate and let the TV adapt to it. How many fixed frequency TVs are there out there that are digital compatible anyway if such a thing ever existed.
Just watched the Apple developer video. It recommends leaving the app UI in the system default (which is more than likely going to be 60Hz) and only switching framerate when playing full screen video. This is so the app UI remains “fluid”.
For the Channels app this makes little sense as the choice is only going to be between 50 and 60Hz both of which are fluid. The UI animations only suffer at 24Hz and Channels won’t be using this framerate. If Channels does follow the Apple guidelines in the countries with 50Hz TV it will mode switch back and forth with each play/stop with annoying TV flickers/blanks if you are a channel hopper. However if you are an app hopper then that could be annoying too if the Channels UI was in 50Hz.
The video is also specific about only the 4K ATV supporting the the new feature. I guess that makes sense for depth switching if the driver for this is that Apple is fed up getting complaints about how crap SDR content looks in HDR mode on many common TVs. Not Apple’s fault but they get the fallout.
Don’t know why they offered framerate switching though. Are there TVs that don’t offer HDR 60Hz? Or are the current Movies streamed at 60Hz and they want to save bandwidth by being able to stream at native 24Hz???
Frame rate switching has nothing to do with bandwidth, but it has everything to do with removing judder and 3:2 pulldown. Its currently working in Netflix, Hulu, and iTunes Movies that I’ve tested and it’s working amazing.
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Right, the movies are filmed at 24fps, and the stream is 24fps. Whatever hz your TV is set to, it compensates by adding/dropping frames. This produces a slight judder at certain intervals and is mostly evident in scenes where there is panning or scrolling. 24hz allows for one screen refresh for exactly every single movie frame. You are viewing the source content as it was intended to be viewed.
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