Originally Posted by bruceames
So if 4k requires 4 times the bit rate using the same codec, then the Blu-ray "equivalent" video rate of Lawrence of Arabia 4k is around 12 mbps (with the actual 4K total bit rate at 49 mbps and assuming the video portion is a couple of mbps under that).
Sony are using eyeIO's tweaked version of AVC which (IIRC) is said to be 50% more efficient, so the bitrates of their 4K Unlimited movies are up to half of what they would be if they were encoded with 'regular' AVC. If we double Lawrence's 4K video-only bitrate to what it would be with normal AVC, let's say 90 Mb/s, and THEN divide it by four, we get 22.5 Mb/s, which just so happens to be the average video bitrate of the Blu-ray version, give or take a few kb/s. (Although the 2-disc Mi4K BD version has fat 34 MB/s encodes for each portion of the movie!)
With that in mind, I do wonder whether eyeIO's compression is taking more out of the PQ than we may think, leading to all the complaints about picture quality with certain material. I'm NOT saying that it's ruining everything, as you'd have to work pretty hard to screw up your average specifically-shot 4K demo video, or indeed something as glorious as Lawrence of Arabia, but the nuances of older 35mm material might be getting lost in translation. That's mere speculation on my part, not having seen any of the 4K Unlimited videos (chance would be a fine thing, **** you very much Sony!), but I've heard that HEVC resolves things like grain even finer than what any flavour of AVC can do, so I think we've yet to see the best of 4K video. (And this is before we even get into HDR, HFR, WCG etc.)