I’ve read the forum here as well as others (Reddit, the StackExchange family of websites, etc.), and I’ve not quite found the correct thread that definitively addresses this topic.
I have several video files that include subtitle streams, some of which are marked as “forced.” That is, the subtitle is designed to always be displayed. For my use case, I mostly use this for videos where the language being spoken on the screen is temporarily different from the rest of the dialogue, like a section of a film where the primary dialogue is in English, but the scene features people speaking in a different language. This is also useful for movies and TV episodes that feature people speaking in sign language, or occasionally with heavy accents.
Here’s the complication for this particular use case: I use the MP4 media container. Plex does not display these forced subtitle tracks by default. Yes, I can choose the forced subtitle track within the Plex player, but this is incredibly cumbersome, as the Plex player does not display any easy way to distinguish between multiple subtitle tracks, as is the case where one has a forced subtitle track, and a normal subtitle track with full subtitles for the same language.
I fully understand the advantages of other container formats like Matroska; use of MP4 is a conscious choice, since I’m deeply invested in the Apple device ecosystem, and want to avoid transcoding at all costs. Any solution that suggests switching to a different container format is a non-starter for me.
With these same files, other media players (Quicktime, VLC, and others), the forced tracks are automatically displayed, without any action from me. This tells me that there is some combination of track metadata flags, file-level metadata, and features from the media player that make what I want possible. What is the magic combination to get this to work in Plex? If the answer includes, “Plex needs to add support for this,” where is the feature request so that I can add a vote for it?
