Peertube is server software from Framasoft. It uses webtorrent, HLS and activitypub protocol to stream a/v content to client devices P2P (see "Fediverse"). It's not a blockchain, however if you install the Hive-Tube plugin onto a Peertube server, then the content can be monetized.

Videos can be removed from Peertube servers, just like 3speak servers, so those videos are not immutable. The blockchain that those videos get connected to, Hive in this case, is immutable.