Plex burn non-English SRT subtitles. Is this a feature or a bug? (and other questions)

[Bjoure]

Server Version#: 1.20.1.3252
Player Version#: 6.60.10.6637

Hi all, I’m using TCL 55" 6 series 2020 TV, running the latest server/player.

All in all everything’s up and running smoothly. 4K, HDR, etc. That is, until I try to play something with non-English SRT subtitles.

I set subtitles burn to “only image formats” and turned on Roku caption mode. I usually watch without subtitles, or with English SRT subtitles. Plex would direct-play all of them, as far as I can tell, without any hiccup.

But the roku Plex app always burn Chinese SRT subtitles, whether they are embedded in the video file or external, whether they are encoded in UTF-8 or not.

I then tried playing SRT subtitles in other languages, it looks like Plex would burn all of them. The only SRT subtitles Plex won’t burn are the ones in English.

I read the only other thread that seems to be about the same issue I had.

https://forums.plex.tv/t/bug-language-code-in-external-subtitle-filename-triggers-roku-to-burn-subtitles/540857/2

So I renamed my SRT files to delete the language code, and Plex recognized them as unknown language.

I could direct-play them on my TCL roku TV this way. The problem is the subtitles is all square boxes-- no characters whatsoever.

I do not understand, Is this a technical limitation on roku, or a bug?

For what it’s worth, from the tests I have done, the burn-in isn’t triggered by 1) audio transcoding, or 2) SRT file character encoding (UTF-8 or not, no difference), or 3) video file format, resolution, HDR, etc.

If anyone has any insight, please let me know. Thanks.

[BigWheel]

The Roku just cannot render the Chinese characters that is why you get squares when unknown and it tries to direct play. The when you label tag it the app I knows it cannot render them and transcodes instead so they show up.

[Bjoure]

Understood. It’s disappointing. Plex could do a better job telling its customers all the intricate limitations on its various apps. Had I known this, I’d probably get Android TV or Nvidia shield.

Also, the latest server build seems to have broken language codes? I use “zh-hans” to indicate simplified Chinese, which conforms with latest W3C standard. Plex used to recognize it no problem but now, they are all “unknown.”