Help me with transcode buffering issue when burn subtitles on specific devices!

General Discussions
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1

Hello fellows and Plex team,
Recently,I‘ve been experienced some weird issues when trying to play movies with PGS or ASS subtitles,My PMS is running on a pretty powerful linux machine as a docker container from linuxserver.io ,and it has an E3-1231v3 cpu and a GTX1650 graphic card, and it also runs a Jellyfin server for my friends.it has been worked perfectly fine with Hardware acceleration enabled, even when transcoding some high-bitrate Remux files.
But I noticed that when using specific client devices playing same video ,the Server just can’t run fast enough, here is a list of results:
Plex on Xbox series X —buffering
Plex on LG C2— buffering
Plex on ChromeCast with google TV—buffering
Plex on Mac—fine
Plex on iPhone—fine
Plex on iPad—fine
Plex for HTPC----buffering
Jellyfin on any devices—FINE
Its is weird ,because I test them with same setting: force burn PGS subtitles and transcode to 20Mbps 1080p.

Anyways ,SORRY for my English! and appreciate if anyone can help me fix it or tell me why.

2

does it work at all if you use a lower bitrate?

5

no, Still buffering, and the server has low cpu gpu usage ,and low disk read speed , it does will play after buffering but only for seconds, then go on buffering.

6

Just so understand, they play fine on those devices when subtitles are not enabled?

Like what happens if subtitles disabled and you set it to transcode to 20mbps/1080p ?

7

it will work perfectly fine on any devices.

8

the problem is,Jellyfin on the same server can handle any of these,I dont understand why,'cause they share the same GPU, it’s like so they use different transcoder?

10

Does it transcode those files with subs on jellyfin? Perhaps the player for Jellyfin has support for those sub types, while some on Plex still don’t.

11

YES,I forced subttile burn-in in Jellyfin ,and I can ensure that it was server who did the rendering.

12

yeah they would not have the same transcoder as us.

PS. You don’t need to quote a reply just above yours. that is what we all assume you are replying to.

13

sorry,still new to this forum.got it.

14

PGS subtitles should be able play on LG UHD sets at least without transcoding now in 5.44.3 if you set to automatic but I know that does not help with ASS subtitles

15

but it is really an issue,diffrent clients cause a diverse server performece,it must be a bug or something.

16

wow,that’s is really nice,thanks for the information.

17

Subtitles support in Plex is very poor and it has become even worse in the last couple of years. I do not think they will fix it, it has been like that from the beginning.

Sometimes just having subtitles there but NOT activating them would still cause transcoding. Plex argument: We start transcoding even if you are not using the subtitles because you might decide to activate them later on.

18

All subtitles burning pretty fine without any issue on all of my mobile devices,but for TVs and Game Consoles,it sucks,I dont know why,but jellyfin just did it well ,so i think this is a bug tiggerd by specific situation.AND IT NEEDS TO BE FIXED!

19

Can you turn on logging to server in the LG app or Xbox and reproduce issue then get the server logs.

20

okay,I will try it tonight,I’m at work now,thanks for that.

21

Plex Media Server.log (617.0 KB)

Around 09:59 local time,I played the movie,it started to buffer,then I changed resolution to 1080p 20Mbps,it buffered for seconds before playing,then the stutters came up.

22

And I played the same movie on jellyfin with the same settings(Burned in the same PGS subtitles 1080p 20Mbps), no issue.

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23

It’s been a week,any updates？