AppleTV4K Plex 8.6 stutters on 1080p playback

[andreizm]

Server Version#: 1.28.0.5999
Player Version#: 8.6

I noticed recently that playback of HEVC encoded 1080p content has very noticeable stuttering. Both audio and video are using DirectPlay and neither bandwidth nor CPU on the server seem to be the culprit. This is definitely something new because I used to be able to play the same content just fine.

Turned on debug output during playback and it shows significant frame dropping.

Is this a known issue? If not, what other data should I gather to help investigate this?

I’m attaching the logs from AppleTV app.
logging.zip (1.4 MB)

[raxiel87]

in the apple tv setting try to enable frame sync under setting/video/

[andreizm]

in the apple tv setting try to enable frame sync under setting/video/

You mean Match Frame Rate? That has nothing to do with it. I’ve had it at the same setting forever, but the stuttering issue appeared only in the last couple of weeks or so.

[skc176]

Having the same problem. I managed to narrow it down to 1080p HDR streams from Netflix. 4K HDR are fine from anywhere. 1080p HDR are fine from everywhere else except from Netflix. Also only happens when direct playing. Direct streaming works fine. OP has a 1080p HDR video from Netflix.

Match Frame Rate setting does not make any difference. Direct Play/Direct Stream does.

[andreizm]

Interesting, I think you may be right. Any word from the support staff?

[andreizm]

Any comment from support? @ChuckPa?

[ChuckPa]

I don’t normally monitor ATV.

I do see this in the logs:

022/08/02 19:03:44.967 (547 MB) (437866) ➖ PMKPlaybackEngine.m:666 | Received timeline response: <PMKServerTimelineResponse: 0x281777380>
2022/08/02 19:03:44.976 (548 MB) (438043) 🔧 PMKMPVVideoPlayer.m:951 | event: set-property-reply
2022/08/02 19:03:44.976 (548 MB) (438043) 🔧 PMKMPVClient.m:508 | [cplayer] v: Set property: mute=false -> 1
2022/08/02 19:03:49.400 (699 MB) (438126) ⚠️ PMKMPVClient.m:496 | [cplayer] warn: 
2022/08/02 19:03:49.400 (699 MB) (438126) ⚠️ PMKMPVClient.m:496 | [cplayer] warn: Audio/Video desynchronisation detected! Possible reasons include too slow
2022/08/02 19:03:49.400 (699 MB) (438126) ⚠️ PMKMPVClient.m:496 | [cplayer] warn: hardware, temporary CPU spikes, broken drivers, and broken files. Audio
2022/08/02 19:03:49.400 (699 MB) (438126) ⚠️ PMKMPVClient.m:496 | [cplayer] warn: position will not match to the video (see A-V status field).
2022/08/02 19:03:49.400 (699 MB) (438126) ⚠️ PMKMPVClient.m:496 | [cplayer] warn: 
2022/08/02 19:03:50.011 (718 MB) (438107) 🔧 PMKNetworkTask.m:201 | Started: 93: seatac (b66dda265e6ea5d724810ee0f0b97f38eeeb8238): GET /:/timeline?bufferedTime=136&col=0&context=preplay&duration=5157536&key=/library/metadata/32834&location=lan&playQueueItemID=56481&playbackTime=5106&ratingKey=32834&row=0&state=playing&time=4420

Don’t know if the ATV CPU is spiking or the server.

I will test myself here with HEVC

[ChuckPa]

Testing here, using an ARMv8 CPU (DS418 NAS)

I get the HDR direct play into a HDR TV with 8.6 (build 3177)

The NAS CPU did spike up hard (it’s a small CPU) while it filled the ATV’s buffers but then settled to what you see above

[andreizm]

It’s definitely not the server CPU at fault. This is graph of CPU on my NUC where PMS is running on. There’s an initial spike, of course, but then it settles into a regular rhythm.

Additional supporting evidence is that this video plays just fine on my Nvidia Shield. So it’s the ATV player that has the issue. And it started happening (based on timing) after 8.6 release.

Could you tag someone who’s monitoring this ATV forum?

[skc176]

The videos that stutter on the ATV are fine on a Firestick 4K & 4K Max. This has been happening for a while. ATV using direct streaming instead of direct play work fine.

[andreizm]

Bump

@DaveBinM @anon18523487 - could you please take a look?

[anon18523487]

The error that Chuck mentioned above is typically caused by a badly muxed file. Try remuxing it and see if that helps.

[andreizm]

If it’s a badly muxed file how come it happens only with DirectPlay and not DirectStream?

[DaveBinM]

Because when something is played via direct stream, we remux it

[andreizm]

Okay, a couple more questions then. How come the playback of the same supposedly badly remuxed file was fine before 8.6? Did something get fixed in it?

Also, is there a way to tell if a file is badly remuxed using ffmpeg or something?

[skc176]

It has been happening long before 8.6. Plenty of reports on reddit going back a couple of years (as far I remember).

[BrazMan]

Hi All!

I recentlly convert all my library to H265 MKV files with EAC3 384K audio using ffmpeg and since this i am having this “issue”. When i try to direct play the files on my wired 1gbps network i got Frame-stutter. On ATV 4K it goes better… but on the non 4K model is terrible.

I see some posts about this since 2019 but nothing that really fix it .

If i transcode it works fine (same files). I already try to change the setiing on video but does not work. The only way that i could play the file fine was transconding everything.

Detais:

Server Version#: 1.25.9.5721 (unraid)
Player Version#: AppleTV (Standard / 4K) models withe latest iOS and Plex App

Any help will be appreciated!

THX!
Braz.