All About Plex Subtitles

This month’s sponsored Plex tutorial dives into a frequently requested topic: subtitles.

I will confess that I am not a frequent subtitle user but I know that many of you out there use them quite frequently. One of the challenges of subtitles is getting them to work in a way that won’t trigger a transcode.

Many of us use Plex as a way to store our Blu Ray movie library on our server for convenience. And typically Blu Rays use the PGS subtitle format which are essentially image files that Blu Ray players overlay on top of the video being played. So if you are ripping Blu Ray files and including subtitles in that rip you’ll have those PGS files embedded inside the MKV file you’re using.

The problem with the PGS format is that very few streaming players support them natively. In my testing I’ve found only the Nvidia Shield TV and Apple TV support that. All of the other players I tested triggered transcoding to bake in the captions before sending the video to the client.

The most compatible solution I’ve found are SRT formatted files. These are essentially ASCII text files with time stamps that most players support natively without the need for an additional transcode. Plex Pass users can search for and add SRT files in the Plex interface using the database right on the content playback page. If you don’t have a Plex pass you’ll have to hunt down those files yourself.

Finding subtitles can be tricky as lengths vary from one version of a film to the next. As studios re-release old films on different formats sometimes things don’t line up or like in the case of Star Wars they change a few things here and there that ultimately impact the timing of dialog. Plex does have a subtitle offset feature that we’ll cover in a future video to better align dialog.

A PGS Encoded Forced Subtitle

Another topic we covered are “forced” subtitles that only appear when another language is spoken. A great example of this is when Jabba the Hutt is speaking at the beginning of a Return of the Jedi. Force subtitles need to be enabled for playback like other types of subtitles and the same rules for transcoding apply here too – if you have a PGS encoded forced subtitle it’s going to force a transcode even if those subtitles are used for a very small portion of the film. These are the types of subtitles I use most often.

There is much more to cover on this topic but I have found SRT encoded subtitles to be the most compatible but also the least attractive. How they look will largely depend on how the client renders them. The good news is that because they are just straight ASCII text they are very easy to edit.

Subtitle Edit for Windows

I found a great open source (free) utility called SubtitleEdit that is extremely powerful for editing SRT files. It can even convert PGS to SRT. It only runs on Windows but there is a version that runs in a web browser on their site.

There is much more to cover on this topic. Definitely check out the video and leave a comment about what you’d like to see next!