It is a great step ahead that I can by now add subtitles.
Alas, it doesn't help my daily life all too much, since quite often I get subtitles, sometimes in more than one format, together in the respective container.
I can play them with VLC, select them with VLC, but I can't import them into kdenlive.
May I refer to my respective posting in the ffmpeg mailing list, please:
https://superuser.com/questions/1688760 ... 11#1689411

I understand that these subtitles are images. And i understand that I need an additional file for the time stamps. I wouldn't necessarily need an editor, at least not in most cases here, but just an extra track into which the subtitles can be extracted / dumped. Similar to the overlay in VLC. So that, when editing video / audio, the parallel, grouped, subtitle track gets cut, pasted, duplicated a.s.f. in sync with video and audio.