4K playback not working on Apple TV 4K

apple-tv

#1

I have a bit of a mystery on my hand.

I am running the latest version of Plex Media Server, and the latest client on Apple TV. Plex is completely unable to play back any 4K content.

My server can transcode it easily enough as it can transcode and playback easily on non-4K Apple TV.

However the 4K apple tv timeline makes it look like the server is fast forwarding through the content. Any help would be great appreciated.


#2

Okay, it’s looking more and more like there’s a bug in PMS for transcoding 4K content.

I’ve tried a variety of things now; and the only common theme is that PMS completely ■■■■■ itself when it touches 4K content on a 4K player.

Here’s the devices I’ve attempted playback on:

  • iPhone 7 w/ Plex for iOS 4.29
  • iPad Pro w/ Plex for iOS 4.29
  • Apple TV 4th gen (1080p model)
  • Apple TV 4th gen (w/ 4K)

All devices except the 4K apple tv receive 4K content transcoded and properly downscaled. Apple TV 4K shows a black screen and a progress bar that make it appear as if the content is being fast forwarded.

I’ve tried this via two different Plex Media Server boxes. One an Ubuntu server running on a Dell PowerEdge T30 and the other running on Windows 10 (quad core Kaby Lake i5). Both of the react in exactly the same way.

I am seriously at a loss here, and would love some suggestions or ideas.


#3

@tmertz said:
All devices except the 4K apple tv receive 4K content transcoded and properly downscaled. Apple TV 4K shows a black screen and a progress bar that make it appear as if the content is being fast forwarded.

When I get a situation like that it’s usually because that particular HEVC format isn’t supported by tvOS. What Plex does is to convert the container (if necessary) to mp4 and then the client plays it as a mp4 HEVC 4K video. But if the received mp4 video isn’t compatible Plex sends it anyway and the client goes banana. This happens to me with most 4K HEVC demo videos I have downloaded.

You’d need to verify if with a video supposed to work (for example Planet Earth II in 4K HDR plays well… Try to find a “demo” :smiley: ) you get no issues.

Another thing you may try is to disable the “Direct Play” option in the client. In that way the server should be forced to transcode it, hopefully still in 4K (I think it does, but with my server it goes slower than a slideshow). If you have the horsepower needed that could be an option.

I’ve tried this via two different Plex Media Server boxes. One an Ubuntu server running on a Dell PowerEdge T30 and the other running on Windows 10 (quad core Kaby Lake i5). Both of the react in exactly the same way.

Because they are basically the same server (well, assuming the version is identical). The platform running it doesn’t matter.


#4

Hi Jecht,

Thanks for your suggestions. :slight_smile: I’ll try to find a sane sample to verify.

I have tried to disable Direct Play. But that changes nothing. Still a black screen with a progress bar that’s fast forwarded. :confused:


#5

@tmertz said:

I have tried to disable Direct Play. But that changes nothing. Still a black screen with a progress bar that’s fast forwarded. :confused:

Can you at least see if Plex is transcoding? You may want to monitor from your PC what kind of CPU and network activity you’re getting. Also in the Plex web interface there are some info about how a video is currently played.

I am not much of an expert on forcing the transcoding because my goal is always the opposite. But I was quite sure disabling “Direct Play” had to do the job. Then to be honest I’m not 100% sure anymore if transcoding it would output in 4K (but I was quite sure it did).

Still the HEVC 4K direct play is mostly working for me (and other people from what I’ve read) now, so I would investigate more in finding a format that is liked by the Plex client. If your PC is powerful enough you may even consider to convert beforehand the videos yourself.


#6

Plex is stuck in a kinda transcoding loop. It shows up on the server dashboard, but even here the behaviour with apparent fast forwarding is replicated. :confused:

I have plenty of computing power on hand, so converting might be an option. But here’s a fun little twist. The Plex client for my tv (an LG something-something), readily plays back 4K content no problem (not sure if that’s transcoded or not, though. I will have to check into that.


#7

That’s most likely because the LG webOS API support more formats than the Apple TV 4K. It’s the same with the Plex Exoplayer on my Bravia with Android TV (when it works, sure!!). It can play 4K HDR HEVC videos at 60fps for example (again… when it works, sure!!). Those same videos in my ATV4K may have the same behaviour you’re reporting.

The problem with the ATV4K Plex client is that we are limited by the formats supported by tvOS (basically the ones iTunes likes, when in MP4).


#8

@“Jecht Sin” said:
That’s most likely because the LG webOS API support more formats than the Apple TV 4K. It’s the same with the Plex Exoplayer on my Bravia with Android TV (when it works, sure!!). It can play 4K HDR HEVC videos at 60fps for example (again… when it works, sure!!). Those same videos in my ATV4K may have the same behaviour you’re reporting.

The problem with the ATV4K Plex client is that we are limited by the formats supported by tvOS (basically the ones iTunes likes, when in MP4).

The limitations of the ATV4K Plex client using the ATV4K native player can be overcome by purchasing at modest cost Infuse or MrMC both of which have a decent Plex client & will Direct Play pretty much all media.


#9

Just want to chime in and say I have the same issue of both the ATV4K and Plex “Now Playing” seeming to fast forward through 4K content. The “Now Playing” status flashes quickly between Buffering and Playing the entire time.