Little/unclear/no documentation on Assets uploading API

[bitspresso]

Background

Hey, as a newcomer to Livepeer, first of all I directed myself to documentation. As available SDKs do not meet my requirements (no support for the stack), the only reference would be API section.

Details

Starting from Asset->Upload an asset, I've been confused. Yes, I receive a JSON - so, what's next? What is the url property and how am I supposed to deal with tusEndpoint? What about encryptionKey: is it arbitrary or should I retrieve a specific one?
After digging a while, I found teeny-tiny block of information regarding direct upload here, which, surprisingly, was misleading (at least for my case).

Still having a bit of patience, so I'll stick with a messy workaround.