Earlier quoted context omitted.
> Not true at all, most YouTube videos are offered as plain webm files. It's been a while since I've written a video streaming scraper but it used to be quite common for a file to be served over HTTP but that file was a small "shortcut" type file to an RTMP stream. So a webm file wasn't the content itself but instead a pointer to where to stream the content from. I'd imagine the same would still be true for YouTube s…
This hasn't been the case in a long time, most streaming sites no longer do RTMP unless specialised cases, because of scaling and ease of scaling. They're mostly HLS or equivalent now.
HLS is not about downloading a file, it's about downloading chunked data. It wasn't intended (though it can't be prevented) that the chunks would be used to recreate a video in full, unlike with a stream of bytes from a HTTP GET which are very much intended to be recreated in full at the receivers end.
HLS really only uses HTTP transport as headers to circumvent many firewalls (and in fact you can do this with RTMP too, eg RTMPT) but aside from that it's a completely different beast to GET.