Thanks, Popper, all that info is a great help. And I do like to know if subtitles are optional. Very distracting to watch a movie when the subtitles are in the language you're hearing
As for hardcoded, hard-coded (or even hard coded) I've just checked the Oxford English Dictionary and none of those appears, so the choice is yours.
I think I would opt for hard-coded - and I think any version is generally understood to mean "you can't turn the bloody subtitles off" !! Â
I don't know of a decent alternative
PS An added thought: if we post a themed movie would you like us to supply that info when we upload or leave it to you so that it's in a standard format?