Muxite

Muxite is the companion app for a Muxite server: the MKV stream manager you run alongside your own media library. Browse your libraries and open any file to see what is inside it: every video, audio and subtitle track, with codec, language, channels and flags. Rename tracks, set languages, and switch default and forced flags in place. Remove tracks or attachments and watch the remux run as a background job. Add subtitles from OpenSubtitles or a file, edit them, or fix chapters and tags without touching the rest of the file. Everything happens on your server. The app signs in to it and shows you what is there; nothing is stored anywhere else, and there is no account beyond the one you set up on your own machine. You need a Muxite server to use this app.