I was waiting until I saw something show up in my feed to verify and I just saw it.
Peertube is the fediverse version of youtube. Different peertube instances can connect together so people can view videos from all over the Internet from the one user interface.
I was running some testing figuring out what I could federate with, and I found that if I plug the URL from a peertube channel into my lemmy search, it shows up like a community. Then I can follow it and new videos will show up in my lemmy feed. (I expect the same would work in kbin)
So for example, the minetest videos channel is at https://share.tube/c/minetestvideos/videos – Just plug this URL into search, and suddenly minetestvideos is a community you’re following on lemmy or kbin, and new videos will show up in your feed and you can watch them and comment on them right from here!
It’s a really great example of how ActivityPub support lets you connect things you’d never expect to be able to connect. Imagine if on reddit you could just subscribe to a youtube channel!
Tilvids doesn’t federate like other peertube instances, which can be an issue. I don’t know how federation with mastodon and Lemmy are, but peertube doesn’t federate with it. (If tilvids does federate with Lemmy that’d be amazing because there’s some great content but I’m not going to specifically visit the site… I’m going to give that a shot!)
Another thing is that most of the time federation starts with the time you subscribe for the first time on an instance. The peertube channel I subscribed to has 3 videos on my Lemmy instance but hundreds on the parent instance. This is normal behavior for activitypub. It’s unusual the way Lemmy (and presumably kbin) pull the history of communities the way they do. I suspect there’s something going on to achieve that which may not happen with every kind of community.