Turn on the subtitles that came with the stream
Provider tracks, embedded tracks and why a track can be listed but grayed out.
Most films and series carry subtitle tracks. mtivi reads the ones inside the file as well as the ones your service lists separately.
Choose a track
Open the player controls and choose subtitles. Provider tracks, embedded tracks and any file you added appear in the same list.
A track that is grayed out
mtivi checks tracks before offering them, and grays out the ones that are empty or broken. That is deliberate: a dead track that silently shows nothing is worse than one you can see is unavailable.
Picture-based subtitles
Some discs and broadcasts carry subtitles as images rather than text. They display normally, but they cannot be translated or restyled, because there is no text in them to work with.
Live channels rarely carry subtitles at all. When a stream has none, mtivi can generate them on the device instead. See Create subtitles when a stream has none.
Appearance
Size, text color and background are in Settings, then Playback. See Change how subtitles look.
Related reading: getting captions back on live TV and VOD.