Are 4k streams better than regular bluray? I'm really enjoying 4k streaming on Netflix/Amazon/Vudu because it looks a heck of a lot better than their 1080p option, but haven't really done a comparison.
4K streams favor increased resolution over bitrate at this point in time, providing a higher amount of detail, but a bitrate that isn't quite high enough for the resolution. Essentially, with 4K streams, you're getting a bitrate close to 1080p Blu-ray quality, but a resolution that significantly higher.
Standard Blu-rays are more balanced, providing a bitrate that is generally appropriate for the 1080p resolution.
At the end of the day, trust your eyes. Personally, I have found that 4K HDR streams have hit the point where I don't care about the added quality of UHD Blu-rays. The increased detail and clarity is definitely there, in the small handful of movies actually mastered in 4K, but it's not necessarily worth the purchase.
Right, but the dude was asking about "regular blu rays" which are still 1080p VC-1/H264 right? So I think he's wondering how a 4K iTunes movie (HEVC) compares to an HD BR. The latter will for sure have a higher bitrate but I'm curious if Apple is opting for smaller file sizes or higher bitrates with HEVC's efficiencies.
Let's do this.
In
this post, we know that John Wick is 5.39GB in what seems to be either 1080p or 4K HDR. 5.39GB = 43,120Mb.
John Wick's runtime is 1 hour, 41 minutes, or 6060 seconds. Divide 43,120Mb/6060 seconds, and you get an average bitrate of around 7.12Mb/s.
Based off that bitrate, I would have to guess this is a 1080p HDR stream as speculated in that thread. h.265 is capable of bitrates around 50-60% of h.264 at the same quality, so this would be close to a ~15Mbps h.264 bitrate at 1080p.