HDMI 2.0a, HDCP 2.2, 4K UHD, HDR…uh…hut-hut? No, this is not a Tom Brady audible while running the fire drill deep in the red zone. These are the buzzwords you were probably inundated with if you were anywhere near a TV this holiday shopping season. Or…not. Because while you may have seen terms like “4K ready” or “4K compatible”, or any other remotely plausible way to mention “4K! (but just barely)”, there are certain requirements for your TV and whatever you wish to connect to it that truly determine whether you will see what 4K UHD can be.
Beginning with HDMI, like most modes of communication there is a language used for formal occasions. (“We didn’t spend all that money on college for nothing, young man!”) Most of the stuff you currently have with an HDMI connection is probably version 1.4. Some may be older. That’s okay, but important because actual 4K UHD video requires at least HDMI 1.4 to work at all. Not that a 4K TV won’t work with older devices, of course. It just won’t be 4K without upscaling, which can produce various results.
Alas, trying to shove the data for four times the resolution down the same sized pipe designed for “standard” HD means something else has to give. Mostly refresh rates, in this case. Refresh rate is what largely determines whether objects move smoothly, or more like Rudolph the Red Nosed Reindeer. In audio terms, think sample rate (44.1 khz) as opposed to resolution (16 bit).
The maximum refresh rate of 4K content over HDMI 1.4 is 24 or 30 frames per second, which is the basic minimum by today’s standards. Much HD content is now 60 fps, and many of the better HD displays distinguish themselves by using their own processing to push out to 120 and 240 fps to smooth out the ride.
So. With HDMI 1.4 you can see basically the same picture as HD, at the lowest frame rate, but with four times the resolution……which testing has shown can only be noticed once you’re within about three feet of a 50-60″ display. With roughly 40″ or less displays, you’re probably going to start seriously invading the TV’s comfort zone before you notice much. Back off, mister.
Where am I going with this? Anything you buy going forward with an HDMI connection should be HDMI 2.0. Period. Ask. Verify. Because the things that are going to give substance to the 4K revolution are emerging right now, and they require the larger bandwidth pipe that 2.0 provides.
Refresh rates above 30 fps at 4K resolution. Enough said on that.
HDR is probably going to be this year’s video buzzword. It should be. High Dynamic Range video can bring grown men to tears. (Disclaimer: Billy Dee’s trophy speech eulogy for Brian Piccolo in Brian’s Song may be required for grown men over 50.) I won’t get pedantic about describing HDR here, but give it a Google to find plenty of breathless reviews. HDR is a dramatic improvement even at HD resolutions that is noticeable at real world distances. Yes, please.
The other developing use of the larger data rates HDMI 2.0 provides is color depth. Akin to the 16-bit digital audio sample mentioned previously, HD video can have up to 24-bit color depth. On top of this is color data compression, which shows up obscurely on spec sheets looking like 4:2:2 or 4:2:0. Because we are much more sensitive to gradients in black and white, it is the color gradients which are squeezed out. HDMI 2.0 provides the bandwidth to increase bit depth, and use less or no compression in various combinations for more detailed color variation. In plain English, you will notice much less color banding in those beautiful sunrises and sunsets.
If you’re considering laying down some of that Christmas bonus on a Super Bowl Sale TV, remember 4:2:2 is more than a defensive back formation, and call for HDMI 2.0 if you want to go long.