Hello there,

So I've got some files being muxed into an mkv file but I'd like to add a subtitle to it. This is what I'm currently doing but the subtitle does not load automatically and the naming instead of language (eg English) shows ass.. Any ideas how to fix these two?

Code:
ffmpeg -i video.mp4 -i audio.m4a -i subtitle.vtt -vcodec copy -acodec copy final.mkv
Thank you!