Trouble with MKV + subtitles + Plex

[alumriel]

Edit/Update - External SRT subtitles working fine now, with MKV without embedded subtitles. Thanks again for all the tips!

Hello folks,
New user here.
I'm having issues with external subtitles not working with my MKV rips. I'm not sure what I did wrong during the rip, but maybe there is some option I need to enable or disable.

End goal - playback MKV rips of my UHD movies, with external Chinese subtitles (for g/f), since most don't come with them on the disc.
Behavior - When playing back the movie in Plex, I can select the chinese subtitle file, but it displays English during playback (and the SRT files on contains Chinese). So it seems to be clearly forcing the internal English subtitle for some strange reason. I also noticed that if I attempt to display the baked in Spanish or French (which came with the movie), Plex errors out and won't play the movie.

Any ideas what I missed during the rip process?

Thanks!

[Woodstock]

External subtitles aren't something MakeMKV can affect. This would seem to be a Plex issue, because you are relying on it to merge in the external subtitle file on playback.

[alumriel]

I’m not sure I follow, because I have other MKV files I got from elsewhere that play fine with external SRT subtitle files.
Clearly something is different with the MKV files I created myself.

[dcoke22]

Subtitles in Plex is a bit of a messy subject. I assume you've seen this: https://support.plex.tv/articles/200471 ... our-media/

[Woodstock]

I don't use Plex, but, from what I've read, the external subtitles are "automatic" if they are in the SAME directory as the media file, and have the SAME NAME (except for extension) as the media file.

The default for MakeMKV is to replace spaces with underscores, so you get names like "A_Town_Where_You_Live_t20.mkv". To automatically be used by Plex, the SRT file would have to be something like "A_Town_Where_You_Live_t20.srt.cn". You can change the template for names in MakeMKV to use spaces, but the SRT has to match whatever you're using.

[alumriel]

Sorry if I wasn't clear before.
To clarify, I know how to make subtitles work in Plex with an MKV. I have other MKV files that I did not create and they work perfectly fine with SRT subtitle files I've gotten elsewhere.
The problem is specifically with the MKV files I am creating by ripping my own discs. Clearly I'm doing something different than what other people have done to create the ones I got from elsewhere. It could be just as simple as unchecking all the subtitle objects from the tree before export. I'm not sure yet, but I will experiment more. It just takes a while to re-rip for each test, so I was hoping someone here had a quick tip for what objects to include in the MKV file, or what options to select/deselect in the software (if any).

[dcoke22]

I generally rip the English subtitles to my English (and occasionally Japanese) language titles. They are PGS subtitles as is native to blu-rays and UHDs. My Plex server is a Raspberry Pi 4 and thus does not have enough compute capacity to do transcoding. I'm direct play all the time. Fortunately, the Plex client on Apple TV 4K is capable of displaying PGS subtitles without having to transcode and burn them in. This is not true for all Plex clients, some of which require the server to transcode the video to 'burn-in' the PGS subtitles.

I've never had to mess with SRT subtitles. SRT subtitles are text based whereas PGS subtitles are image based. That means PGS subtitles are just a graphic overlay on top of the video. SRT, on the other hand, requires the player to render the text to place over the video. That implies that the player has to have access to a font that can display the language of the SRT subtitles. If you look around on the Plex forums, you'll see a lot of people talking about when Plex detects the wrong 'language' and then displays the SRT subtitles incorrectly.

I haven't experienced the problem you've described, but I can make a couple of suggestions. First, hopefully you've learned how to make a decrypted backup with MakeMKV. Once you've made the backup, you can make .mkv files from that backup much faster than you can make them from the optical disc. This will allow you to test with a blu-ray (no need to test with a UHD until you make a blu-ray work) without having to wait for your optical drive. You can also use the MKVToolNix tools to add or remove subtitle tracks to your .mkv file.

I think you've said you successfully got Plex to display English PGS subtitles, but failed with Spanish and French. It would be interesting to know why Plex failed. There's probably some info in the various Plex logs. In any case, does your Plex have to transcode when displaying PGS subtitles?

I think it'd be an interesting test to make a .mkv without any PGS subtitles and see if you can get an external English SRT subtitle to work. And perhaps a Spanish or French external SRT to work. And then, of course, a external Chinese SRT. I wonder if Plex is correctly detecting and has access to the right fonts to display languages other than English?

If you use MediaInfo to compare one of the .mkv files that doesn't work vs. one that does, what does it show?

[Chetwood]

To automatically be used by Plex, the SRT file would have to be something like "A_Town_Where_You_Live_t20.srt.cn".

I guess you meant "A_Town_Where_You_Live_t20.cn.srt".

[Woodstock]

Shows you how often I've used SRT subtitles...

[alumriel]

Thanks for the replies.
I used MediaInfo to see what the MKV contents are in the other MKV files I got elsewhere, which work fine with my externally sourced SRT subtitle files. What I found was that they either have NO subtitiles, or they have UTF-8 subtitles, rather than PGS.
So I'm going to make new MKV rips without any subtitles and try again.
Thanks!

Edit/Update - External SRT subtitles working fine now, with MKV without embedded subtitles. Thanks again for all the tips!