Choppy 24p w/HDR playback on iPhone XS

Just an FYI but it appears the iPhone XS/Max are having choppy playback with 4K HDR video. James are you aware of this and if so have you sent anything to Apple?

For me it seems to affect local Infuse movies, iTunes, and Netflix HDR content. iOS Beta 12.1 doesn’t seem to fix the issue.

And just like that it appears to have stopped in Infuse. I’ll need to do more testing to completely verify.

Massive stuttering still occurs in Netflix and iTunes but that’s not a problem that needs to be addressed here.

There have been others with similar problems not necessarily on iOS devices that was traced back to something else on the same network hogging bandwidth so many something else was eating bandwidth and causing the chop. Just a thought.

No it wasn’t a bandwidth issue. I checked my network monitor on my Cisco ASA and could verify no saturation.

I ran across this today https://forums.macrumors.com/threads/iphone-xs-max-hdr-problem-in-netflix.2140783/ and other users are having similar issues.

This needs to be re-investigated. The stutter is back. It’s really apparent on any content that has a lot of zooming or panning. It’s like judder you’d see on a TV. I downloaded the videos to my phone and they judder as well. This only seems to affect 24p content. 60fps video seems to play back better.

I’m seeing it, too. I have a hevc 24p hdr 4K file of Blade Runner 2049 and I transferred it local to my iPhone Xs Max and I’m experiencing that judder on nearly every scene that pans.

The picture is stellar, though!!

I’m thinking this might be either hardware or iOS related. It probably has something to do with the 120hz panel in the phone. It’s not just Infuse with the problem… even apples own iTunes content has the problem.

I’m wondering if the Infuse folks raise the issue with apple if it’ll get more traction for a fix.

What brand and model of router are you using?

Cisco ASA 5505 and ubiquiti UAP-HD. I also have a gigabit unifi switch. The judder happens on content that is downloaded and stored on my phone as well as with streaming from my NAS.

We’re seeing the same thing here with some files, and are looking to see if there’s anything we can do on the Infuse side.

If it is in fact a system-wide iOS bug, then the fix will probably need to come from Apple.

After a few quick tests, it looks like this may have been resolved in today’s iOS 12.1 b2 release.

Ive done some testing too and though it seems a lot better I do notice some slowdown stutter on panning shots. Disabling True Tone auto brightness improves it even more. I think it’s safe to say that this is definitely an apple issue and not an Infuse problem.

Side note: thanks for the quick feedback and attention to this issue. I wish other companies (aka Zidoo) provided the same level of support.

Thanks for all of your testing! Sorry about the goose chase but wanted to try and help with the tidbits I’ve gleaned here in the forum. Now to add another gremlin to the possibilities.

I’ll have an iPhone X when the XX is released. LOL

It’s not a hardware or software issue. It’s the OLED display. Google “OLED stutter” and you’ll read of people seeing it for the first time.

OLED pixels can change color/state nearly instantly. LCDs displays, on the other hand, are slower to change and sort of fade between colors/states. Some motions like panning look smoother on LCDs because the frames are blending together and make a nice motion blur. OLEDs can easily keep up with a rapidly moving scene so it’ll look stuttery.

There may be something Apple can do about it to lessen the effect, but it may just be something to get used to as OLED becomes more common.

To some degree yes but if I disable auto brightness on the phone the stutter almost completely disappears. This is only for 24p content. 30fps and 60fps content plays back perfectly without having to do any tweaks. So the issue is with how Apple is handling 24p content in iOS.

Except I did not have this issue on any videos I watched with my previous iPhone X. Now that I have the XS Max, I notice it quite a bit. Both phones have OLED.

turning off auto brightness in accessibility settings should fix the problem. This points to a software or processor issue.

iOS 12.1 beta 3 might have fixed the issue… I’ve only had enough time to test on two problematic movies and they re playing back much better

I don’t know if this helped. Almost all videos I play have choppy playback, and I’m not playing HDR videos, normal mkv, fullhd clips. I did not have the same issues on iPhone X.
Could it be that the display is not capable of synchronizing to the video content, in sense that if you have 24fps content then the screen refresh should also be lowered to 24Hz, like on the AppleTV. This is really strange. If Apple doesn’t fix that soon I will probably return the phone, this is my main multimedia consumption device and it’s very frustrating.

Playback is better with the latest 12.1.1 beta 3 but not perfect. Try turning off auto brightness. It’ll fix your playback issues.