VP9 allowed when?
It's better because:
* it saves bandwidths
* all videos on Youtube are VP9, so no need to waste time on re-encoding
that would explain why youtube-dl > krautchan recently stopped working.
VP9 > VP8
But only for 360p.
>Fact: Youtube encodes every video to both VP8 and VP9, along with H264/AAC.
I don't think so.
My observation is: Youtube used VP8 previously, but switched to VP9 at some point. Every new video you upload now gets a VP9 version. But they didn't bother wasting encoding time to recode all the old VP8s, so they kept them this way.
This video was uploaded less than a week ago.