This might end up a feature request as it seems Plex can’t do this.
First of all I should say I can manage to make forced subtitles turn on automatically in the way most people probably use them.
So here’s my issue. In my library I have a large mix of english-speaking movies and french-speaking movies. I and everyone I share my server with speak both languages, therefore I don’t have any language preferences set in the “Languages” tab of the server settings (Prefer audio tracks to: None and Prefer subtitles in: None), because I just want the audio track at the top of the list to be selected by default (meaning, the original language). And I don’t want the full subtitles track to be selected in both cases, just the forced, in both cases.
But if set this way, it seems there is no way to have the forced subtitles automatically selected for all movies. You either get no subtitles at all (when “Manually selected” is on) or the full subtitles track (not the forced) for all movies (when “Shown with foreign audio” is on), I’m assuming because it’s detecting all languages as “foreign”.
I believe I tried all combinations of settings but I should say I tried this:
Prefer audio tracks in: none
Subtitle mode: Shown with foreign audio
Prefer subtitles in: English
The result of this is forced subtitles turn on automatically for all english-speaking films, but the full subtitles are on for all french-speaking films, including when you switch the audio track from english to the french dub. This means any time you watch a french-speaking movie, you have to turn them off, and any time you switch the english audio to the french dub, you lose the forced ones, and have to turn off the full subtitles.
Changing the language preferences either in the server settings or the account settings yield the same results.
I should add I don’t think this is a unique case at all. After, this is how all dvd/blu-ray players work: if you select the english audio track, you get forced subtitles, and if you select the french audio track, you still get forced subtitles. In my case, it’s french, but this should apply to any language around the world.
By the way, if anyone is confused, “forced” subtitles are the subtitles that only show in a movie when characters are speaking a foreign language in a scene (when aliens speak in star wars, when russians speak in an american movie, etc.).
Here are some specifics of what my files look like:
MKV files
All subtitles tracks are embedded in the MKV
The audio track (tagged as default) and forced subtitles both have the “language” tag set correctly
The forced subtitles track are tagged as both default and forced
I also named the subtitles tracks as “Forced” for convenience
I should say the forced subtitles tracks are not at the top of the list of subtitles, but this should make no difference as Plex is correctly choosing the forced track anyway when a language preference is set, so it doesn’t require the subtitles at the top of the list
I’ve extensively tested this and I would greatly appreciate if someone can shed some light on this.
Thank you so much.