The cpu issues I detailed above are specific to high-bit rate mpeg2. H264 uses hardware decoding and should not be affected.
If you’re seeing problems in the UK, send me a sample as detailed above. I only received one from @Valentine13 but that one played fine on my ATV4. Also make sure you are using v2.1.39
FYI, I installed V 9.12.204 and I’ve no stuttering anymore.
Thanks @Valentine13, that helps narrow things down. I took another look at your sample and I see it’s using an uncommon feature of H264 which is triggering an edge-case. I will work on a fix.
Thanks for posting. Didn’t realize I had auto update set and had one ATV4 upgrade to tvOS 11. Did notice some slight stuttering (primarily on scrolling tickers) hence I decided to downgrade. What an odyssey followed.
First, I wanted to take some screenshots on the ATV. Found my USB-C cord ordered last year (just in case 
) and went to Xcode to take screen shots…ha!ha!..found I had to upgrade Xcode…then found I had to upgrade to Sierra. After several upgrade failures, finally got Sierra, then Xcode…screenshots taken. Then downgrade to tvOS 10.
Now, I’m loading all of my tvOS apps to replicate prior status. It’s been a pita, but I was glad to still be able to downgrade.
Thanks to all for the warnings and tvOS 11 feedback on ATV4…might not have caught this in time as we are still digging out from Irma. These forums and contributors (especially @Scott) saved our stellar experience on Channels.
I also have the stuttering described above after upgrading to tvOS 11.
New TestFlight build is available which fixes some remaining issues with H264 decoding.
No change to mpeg2 decoding yet. We’re trying to get in touch with Apple about the issue.
Interestingly my system auto updated to tvOS 11 (64 GB) on my Apple TV, and so far so good. Recoding from MPEG-2 streams, wired internet, and haven’t tested 1080i input yet.
The CPU issue in tvOS 11.0 seems to be fixed in the new tvOS 11.1 Developer Beta released today.
Just upgraded to Xcode 9.1 beta and was able to verify that tvOS 11.1 Beta uses 75-80% CPU again when running Channels. So this issue will be resolved once tvOS 11.1 is released publicly.
tvOS v2.1.40 is now available on the App Store with a fix for the H264 decoding issues. The mpeg2 issues will be fixed when Apple releases tvOS 11.1
TestFlight build resolved my stuttering issue on the 2 chan I checked.
Thanks a lot for your work^^
Hmm, wonder when an 11.1 public beta might show up…
Are you seeing reduced CPU usage on the ATV 4K too?
The Apple TV 4K is affected too, but it has a much faster CPU so it doesn’t stutter during playback on either OS.
11.1 beta, just went public.
Been running 11.1 for a few hours and it appears to have resolved the stuttering for me.
tvOS 11.1 was officially released today. Please upgrade and let us know if the issue is fixed.
Was this a problem with iOS as well?
No, tvOS and ATV4 only.