Christoph Heinrich
8ea7aa5471
ytdl_hook always set force-media-title, making users unable to force
a media-title via options.
To prevent that, check if force-media-title is already set to avoid
overwriting it.
A better solution would be to use tags like is already done for some
metadata, however that doesn't work when `all_formats=yes` is used.
See cbb8f534b0
A comment was added to hint at why it isn't done via tags.
ref.
https://github.com/mpv-player/mpv/pull/10453#issuecomment-1445277496