Video stuttering when playing some 4K HDR files

Platforms iPhone & iPad
1

Since last update (or maybe the one before that?) some files began stuttering heavily during playback.

The files that are affected are all full, uncompressed remuxes from 4K HDR discs. It doesn’t seem to happen with 1080p remuxes from Blu-rays.

Every few seconds the picture will stutter a bit, it’s particularly noticeable during movements. I tried changing the streaming cache setting from Memory Only to Auto but it didn’t help.

I’m using a Plex server.

I noticed the stuttering on my iPad. Unfortunately, I can’t check right now if it’s reproducible on the Apple TV.

Let me know if you need more details. I know this stuttering wasn’t happening before, it started with a recent update.

3 Likes
2

The problem is with the 1080p upscale to 4K. Enable on Apple TV 4K 1080p in video settings.

3

So I had time this morning to do some tests.

I can’t reproduce the issue on an Apple TV.
I can’t reproduce the issue on a MacBook Pro.
I can’t reproduce the issue on an iPhone.

I can ONLY reproduce the issue on my iPad. And ONLY with 4K HDR remuxes coming straight from a UHD disc. All files of this type show the issue consistently. It’s not reproducible with any other type of file.

I need to do more tests to be sure, but it seems the stuttering stops after letting the file play for a little while (1 or 2 minutes?). Edit: See new comment below, the stuttering doesn’t always stop.

My iPad is an iPad Pro M2 12.9-inch if this info can help in any way.

My network didn’t change. I ran a few Speed Tests against affected files from within Infuse on my iPad and the results are all still good and didn’t change from what I was getting before.

And besides:

  1. It was working perfectly before, I think the problem coincides with one of the last Infuse updates.
  2. It works perfectly on everything except the iPad.

So I’m ruling out the possibility of a network issue.

I would describe the issue as if the video was stuttering every 2 or 3 seconds. It’s very distracting, especially when there is movement.

Please let me know if you need anything else to investigate and fix the issue. Thanks so much.

4

That’s possible but also there have been several iOS updates over the last few months that also may have a hand in the problem.

You may want to also add what version number of Infuse you’re using and what iOS number on the iPad.

5

Right!

I’m using Infuse 8.0.8 on iPadOS 18.2.1

6

I just tried watching a movie and the stuttering didn’t stop after 1 or 2 minutes like originally thought. After 10 minutes it was still doing it. I then stopped the movie, it was too distracting.

I don’t know why in some of my tests it sometimes stopped after a while. It apparently doesn’t always stop.

I just hope this bug will be fixed soon, it’s very annoying.

7

I’m experiencing the same issue on my Apple 4K TV, uncompressed remuxes from 4K HDR discs. Network looks healthy and nothing change from that perspective.

8

If you are seeing playback issues with specific files, it could be helpful to send in a sample file we can review here.

Files of any size can be submitted here.

9

Does that mean you’re not seeing the same issue on your end?

Like I said above, in my specific case I’m experiencing the issue only on iPad (iPad Pro M2 12.9-inch), NOT on the Apple TV I’m currently using (which is an Apple TV 4K 3rd gen). It would be interesting to know if the issue @jmedia441 is seeing is related to the same thing.

ALL the 4K HDR remuxes I have are exhibiting the issue on the iPad. I could prepare a sample if you need one, but again, you just need to try playing a remux that’s coming straight from a UHD disc.

In light of this, let me know if I need to prepare and submit a sample. Thanks so much for your help.

10

Out of desperation, I tried to completely delete Infuse from the device to then reinstall it. Just to see if it would help.

  1. I deleted the Infuse app.
  2. Restarted the iPad.
  3. Redownloaded the app.
  4. Reconfigured the app and connected my Plex server.

It didn’t help with this issue, playback was still stuttering when playing all affected files.

I’m putting this here in case the info can somehow help in fixing the problem.

11

While I am not having the issue across all 4K UHD Remuxes, I am seeing it whenever there is a slow motion scene. Happening across multiple files. The rest of the movie plays fine and the issue is specifically limited to slow motion.

12

I am able to reproduce this on my Apple TV. If I play a movie but press the left key to go back 10 seconds then the stuttering happens. But if I scrub back using the track pad, and go a bit further, it plays back fine. Also if paused for long enough (like 4 mins), it stutters when I resume the video.

My infuse and Apple TV are up to date.

13

Yes that is similar to this thread

14

I don’t believe we have any similar reports that are specific to iPad, but one thing to check would be to see if you are getting similar streaming speeds between all your devices. If for some reason the iPad has a slower network connection compared to other devices, it can possibly lead to buffering or other playback issues.

You can test the available streaming speeds from within Infuse by following the steps in this guide.

Also, if you wanted to send in one of the affected files we can test it here. Samples of any size can be uploaded here.

15

Sending in my sample in reference to my comment here. My network works just fine, I max out my Apple TV’s ethernet limit on speed testing so I’ve narrowed it down to Infuse

16

The Infuse speed test doesn’t really do a “max” network speed it simulates all of the needed overhead to make sure the speeds aren’t affected with the overhead so you may want to still check with the Infuse speed test.

17

I checked with the infuse speed test. That’s the only speed test that is relevant here

18

@james

I tested with Infuse 8.1 and the issue persists, so I uploaded a sample file titled “judder-stutter ipad.mkv”.

This is a sample made from the first minute of a movie taken straight from a 4K UHD disc. You can see juddering/stuttering throughout the sample, but particularly when the camera pans through the trees once the movie starts.

Once again, the sample plays perfectly on everything except my iPad Pro M2 12.9-inch.

I retested my network conditions, and everything is perfect. I can also reproduce the issue on the iPad 100% of the time with all files that came from 4K UHD discs (but NOT with any other kind of file). I’m using a Plex server, if it makes a difference. And the affected files play correctly when using the Plex player app instead of Infuse.

Please let me know if you need anything else to help investigating the issue.

19

I can confirm that this happens to me. I noticed it a lot in severance S02E05 when there was a big panning scene. I tried different files and it was the same. It didn’t happen when playing the same file on plex or on Apple TV+ on the same device.

It works perfectly fine on my old 13 pro max with promotion on, but on my new 16 pro max there are stutters everywhere.

Infuse team: Are you doing a perfect sync to 120hz to avoid stutters? Can’t you just reduce the screen refresh rate to 24p or a multiple of it when playing 24p content?

This is on an iPhone 16 pro max, iOS 18.3.1. No battery-save on, 120hz enabled. It happens on local and remote files.

20

I was having this exact issue with all of my direct 4K HDR rips streaming from a local server. Seems like it was maybe an issue with the current version of iPadOS, since I’ve updated to 18.4 beta the problem has disappeared.