Serviio

Background - I have a WIN11 PC acting as a fileserver, serving mostly HEVC MKV files to my Sony BDP-U700 via DLNA. Denon AVR and Sharp TV. I'm using the Serviiio SHARP TV profile as its the only one that supports the audio formats I need transcoded.

I rarely have any need for subtitles. When i do, they are sometimed present in the movie file(but not always) or I provide a .SRT for for them if not. However , SRT file approach can be problematic and annoying since it will often say thing like "speaking Japenese" or "gasp", "Grunts" etc. In a perfect world - It would only display subtitles for non-english dialog.
If I play these MKV files on my PC instead of the sony bluray, it's clear these files actually DO have subtitles embedded in them (sometimes more than 1), even though my Sony Bluray (or maybe Serviio) does not recognise them or allow me to select them on the DVD player. If i try to turn on subs from the dvd player remote, I'll usually get a "not supported' error or the like.

I am using the following options on the subtitle option page (see attachment)and nothing is set on the languages page. When I play these files on my pc using VLC player , I can select the first subtitle option on, and everything is perfect. Foriegn langauge (and only that) is subtitled without auxilliary description, but if using that same file under serviio from the bluray, it shows nothing without an SRT file and I'm a slave to whaever text is in that file. Should I have something set differently or is the Sony (or Serviio) simply not capable to extract the subtitles from these files that VLC can?
Thanks!

When you select the option to burn in the subtitles, Serviio will take the caption that that is marked as default and burn it in. You don't have an option to select the caption track (assuming the media file has more than one caption track). You could use something like TSMuxer to remove any unwanted caption tracks, but then you are bound to that single caption track.

VLC is a great video player (with a terrible user interface) and plays almost anything without requiring transcoding. Without looking at the Sharp TV profile you're using and comparing it to some examples of your media, I can't say exactly what transcoding you need accomplished. I would guess that the Sharp profile is transcoding more than necessary, but that's only a guess.