RED open up a 4K channel on YouTube and had YT tinker with the VP9 Codec for smoother uploads of R3D vision.
We recently worked with YouTube engineers to enable 4K VP9 encoding, and we are very happy that all new 4k videos uploaded to select youtube channels will now be encoded with the updated VP9 Codec.
You guys need to try it out, It is a considerable improvement. Jarred Land
See more at Shot On RED