When playing AV1 files on appletv, it struggles with subtitles

Plex Players
1

Server Version#: 1.41.3.9314
Player Version#: appltv app (newest)

When starting av1 videos on the appletv with subtitles, it either will not start it, or starting to transcode it with the error that the subtitle isn’t the first stream in the video.

If you then change subtitle to the first subtitle, it direct plays it, and starts the video starts if it also refused to do that, then if you switch back to the subtitle you originaly tried starting the video with, it plays fine, and also direct plays it. So the problem only occurs on the startup of the video.

Other codecs like h264 and h265 do not have this issue.

2

AV1 is not supported by plex.
AV1 is not supported in hw by any ATV.
AV1 is a pretty fringe codec with very little industry adoption.

edit

SDR video with AVC/HEVC (Main/Main 10 profile) up to 2160p, 60 fps

Dolby Vision (Profile 5) up to 2160p, 60 fps

HDR10+/HDR10/HLG with HEVC (Main 10 Profile) up to 2160p, 60 fps

H.264 Baseline Profile level 3.0 or lower with AAC-LC audio up to 160 Kbps per channel, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats

MPEG-4 video up to 2.5 Mbps, 640 by 480 pixels, 30 fps, Simple profile with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats

HDMI Quick Media Switching (QMS) for seamless format transitions

Support for 21:9 and other cinematic aspect ratios when playing movies and shows on compatible projectors and displays6

3

But it at least partially works, is it really not supported officially?

YouTube is using AV1. :grimacing:

4

AV1 wasn’t introduced into the iphone chipset until iphone 15 in 2023. The next Apple TV hardware refresh is expected to have AV1 support.

My J4125 nas will transcode it, but taxes the resources more than I like. My N100 mini pc transcodes AV1 pretty well. I haven’t tried subtitles with AV1.

5

Dude, av1 playback has been supported by plex since… eh version 1.30.1.
And actually starting to get quite the the adotion.!

6

I’m aware, allthough the current one have no problems with AV1, it software decodes av1 with no issues. :slight_smile:

7

Yepp, and netflix, facebook and twitch mm:) so guess the frindge part of the industry is quite big :slight_smile:

8

Even the $20 Walmart Onn streamer will decode AV1 in Plex. That is, unless you need an audio transcode because of a soundbar that doesn’t support Opus, then you get a video transcode as well for… reasons?

@raysv Unless this is your post also, you are not alone: Reddit - Dive into anything

9

Hehe yeah, its not my post :slight_smile:

However i have no problems getting it to direct play, if i start the movie/show, then switch it to use the first subtitle, it starts direct playing it, and THEN i can switch back to the one i actually wanted to use, and it will still direct play it!

So its just a weird and very very very annoying bug. Ofcourse, turning off that it automaticly should use subtitle in my language and manually select it each time, is also a workaround that works! but again, annjoying hehe

I would guess this would be a quick thing to fix from plex devs, not sure if its the plex server, or the actuall apple tv app that does this though.

10

Agree. And in 2027 when someone makes a post with the same issue we can just link them to this thread. lol

11

Sort of surprising as my Apple TV direct plays AV1 (using Channels DVR) without any issues…

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12

Also according to this thread, it appears that there is AV1 hardware support on some newer IOS devices - iPhone 15 Pro at least.

13

That’s not direct… shows clearly a custom software decoder by videolan.

14

Still not transcoding on the server though. Looks to be being handled on the client side.

15

I’ve also experienced this with av1 anime with ass subtitles. I’ve seen a similar reason with the order of the audio tracks as well. I have to switch over, then switch back and it direct plays. Though I never reported such a thing since I had to use a custom client profile to get AV1 to work on the Apple TV in the first place.

Would love a fix as the 3rd gen 4K Apple TV seems to be strong enough to software decode av1. I had otherwise just accepted that I’d have to wait for a new Apple TV device that hopefully supports AV1 HW decode.

16

Even on Android devices that do support HW AV1 decode, I see ASS being transcoded into AV1 in Plex. There is also a bug where you have to set the system settings a certain way to get it to not transcode AV1 when the media has Opus audio.
AV1 on Plex generally feels like it’s in the alpha stages. Hopefully they are working on it behind the scenes.