3D videos in True 4K (4096x2304)
Since you can download the "Original" version of the file, I think you still are going to only get 2 1920 videos side by side, so that isnt 4k, its really just full hd. I use Keepvid to get the files off youtube and that works great. I haven't seen one that is over 3840 pixels wide yet for a side by side formatted 3d video. Its 4k if you mean 4k in width for a 2d video. I don't see anything on the links that would be 4k. That would obviously be close to an 8000 pixel wide video.
|Antz by Deadfisheye|
from Animated Film Title
|The Ladder - Fort Worth Museum of Modern Art by RJD13|
from Lookin' Up!