I may have to crack open my NP-1 at some point and take a peek inside. I don't own a Mad Cats MOJO; it wasn't an interesting product specs-wise.
As for the bitrate for AVC 4K encodes, it's (unsurprisingly) not quite that simple. 35-50mbps is a generalization based on my own AVC encoding experiments and on what I deem acceptable image quality. I'm sure some people would be just fine with less.
Bitrate depends so much on the content being compressed. If the movie is a slow drama, taking place in well-lit locations and shot on a modern digital cinema camera, it will need a lot lower bitrate than an action movie shot on film, full of shaky camera movement and riddled with either film grain or digital camera sensor noise. Generally speaking, of course.
That said, it's certainly possible to deliver AVC-compressed 4K video to playout devices at very low bitrates - if you're willing to take the hit on image quality. Any VOD provider could stream 4K video at 1mbps if they wished. The problem is that the video would look like utter garbage, and the consumers would find that unacceptable.
My testing of the NP-1 suggests UF is not trying to deliver video at ridiculously low bitrates. Like I said earlier, the service tried to push more than 25mbps to my NP-1. Since it couldn't do that for some reason, playback suffered mightily from frame skipping, stuttering and various other glitches. This suggests the stream was encoded at bitrates higher than 25mbps.
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Since I'm in a hurry and won't be able to post for a while after leaving office today, let me make something clear:
All my UF testing has been on the NP-1, and that's what I've based my comments on. I have two 4K professional displays, neither of which runs apps, so I haven't tested UF on a 4K flat/curved screen.
I am most certainly *not* saying UF cannot work. All the necessary technology for 4K streaming is easily available to anyone who can afford it, after all. 4K video streaming exists, as shown by Netflix and others, so I see no technical reason why UF couldn't do that as well.
Someone posted Terminator Genisys as ripped from UF had a filesize of 8 gigabytes. Let's assume that's true. Doing the math says the average bitrate of combined video and audio is slightly more than 11 megabits per second. That's very low for a 4K action movie if encoded in AVC.
And even if encoded in HEVC, I think I would probably find the image quality unsatisfactory, based on my own HEVC encoding experience and 4K HEVC video streams I've seen on Netflix. Again, I'm sure there's a myriad of people out there who are happy with the quality, regardless.