n HDMI 2.0 installations we expected that everything would work as described in manuals. Many of us have done that and got terribly frustrated - it's like troubleshooting in the dark - divide and conquer - replace potential defective components with known good components... unfortunately at this point in time the cards are stacked against you as an integrator.
We feel we need to share our findings on the state of UHD/4K today from a practical - "what do we do in the field standpoint" - to the technical - what is it, what are the numbers and what do they mean.
Finally, we will discuss how to not make the mistakes that we did that ultimately drove us to write this series of articles. Enjoy!
4K UHD Field Testing Headaches Series Highlights:
- What is 4K - What are the Numbers - What do they mean? HDMI 2.0, HDBaseT 2.0, HDCP 2.2, 18 GBPS, 600 MHz and more.
- What Drives the New Higher Bandwidth Requirements
- Testing the Hardware and Infrastructure
- Solutions for Testing & Hardware that Exceeds the Standard
Part 1 of 4 ~ 4K UHD Field Testing Headaches
Part 1 will describe what we did here in our lab to start muddling through all of the "4K" noise. As you will see later, we learned very quickly that this was not just sandy beaches and rose petals, so we buckled up for this journey that will take us an ENTIRE SERIES to cover.
To reiterate - Unfortunately, at this point in time the cards are stacked against you as an integrator . The good news - This is the greatest opportunity in years to be ahead of the curve and become a trusted adviser to your customer! Lets dive in...
We have had many 4K UHD TVs and monitors in our lab since the launch of 4K - we are not going down the path of referencing them by name, but 90% of the market is represented in our samples (by brand - we don't have every model, but we do have mostly the mid to higher end models represented - and that REALLY does make a difference.)
The higher end models tend to have the features we seek - they are mostly all "Smart" - beyond that terminology and "features" vary widely
For sources we used Quantum Data 780C generators (HDMI 1.4x) and DVDO TPGs (HDMI 2.0) and others as reference sources. We also used players - FMP-X10, Nvidia Shield, Smart TVs, Android equipped USB players, etc. We also have EDID readers, so we can see what the display says via HDMI it wants first and will be able to do.
For cabling we used various lengths (.5 M to 5 M) from various manufacturers - some rated 10.2 GBP/sec, some rated over 20 GBP/sec. We also have extenders that use HDBaseT technology and H.264 (HD over IP) technology (encode/decode).
Note: the next article in this series will drill down on the numbers so don't get too hung up on that here.
So, in no particular order here is what we found out when we first started "testing" before we actually wrote a process for testing & documentation:
The displays don't always do what they say they do - what it says in the manual, what they say on the phone when you call the manufacturer, and even in some cases what is actually printed on the HDMI port - often doesn't work.
We glanced on the Internet to see if there was volumes of activities posted - we searched by model number to determine if others were seeing the same thing, and sure enough there were many reports. We learned that there are more frustrated early adopters working on this than we had imagined.
In some online case studies we found work arounds to "force the TV into a 2.0 mode - or in some cases UHD 2160P60 4:4:4 mode - or renaming the HDMI port type to PC - or selecting the menu option for UHD Expanded Color.
In other cases there was only 1 port that was setup for UHD and the rest limited connections to 1080P. Even in some cases, where we did all the turn-on tricks the displays still didn't lock on to anything above 30 fps - certainly not a 2.0 input.
HDCP is also an issue that it's hard to find reliable information on - some ports do HDCP 2.2 and others fail. We saw HDCP 2.2 work at 2160P60 4:2:0 and not at 2160P60 4:4:4 (in the same port).
Part 2 of 4 ~ 4K UHD Field Testing Headaches
Part 2 will briefly discuss the impact of cables and extenders...Stuff we use EVERY DAY that just doesn't quite act the same.
Cables & Extenders:
Cable length matters and it doesn't matter...at first we really were not paying much attention to cables and cable length - most likely because at first they all worked out to the 5 meters we were using. Thing of it is, at first we were only testing to the limits of our sources, which meant 2160P60 4:2:0 and 2160P30/24 4:4:4 and everything worked great.
The Nvidia Shield that we picked up only a few weeks ago does do 2160P60 @ 4:4:4, but it is not a setting you can force - it reads the EDID and sends a 4K signal that will lock on - meaning we got tricked into thinking everything was all warm and fuzzy and working great. When we actually got to the point where we were able to actually force a 2160P60 4:4:4 signal (>17 GBP/sec TMDS throughput) cable length began to matter
In our testing last weekend we could not pass 2160P60 4:4:4 signal more than 6 feet (around 2 meters) - admittedly, we didn't test a thousand different cables, but the results were consistent across 5 major brands. We also did not test powered cables or cable booster boxes. When the cables got longer than 6 feet the picture started to blink - sometimes every 5 seconds and sometimes every 60 seconds. Cable length appears to matter a lot at high bandwidth.
Extenders work and don't work...this is already well documented so no suprizes here 2160P60 4:4:4 8-bit NOGO, 2160P60 4:2:0 8-bit GO HDBaseT is limited by bandwidth to 10.2 GBP/sec and it works perfectly well up to that point and handles HDCP 2.2 fine also. I'm not spending a lot of time on extenders in this article as we were really focusing more on the displays. HDIP is also limited to 4:2:0 8-bit, but HDCP 2.2 works well there also.
Part 3 of 4 ~ 4K UHD Field Testing Headaches
Sources are tricky and HDMI 2.0 reminds me of 5-Play when HDBaseT came out - the spec is there, but some items are optional and not required to call yourself 4K UHD 2.0 - depending on who you are (or more so, who your customer is and what they want to watch) the devil is in the details. Most consumer devices - and for good reason - lock on to the preferred format from the TVs EDID to make sure there is always a picture. They also handle passing HDCP 2.2 keys for encrypted content. Generators are the trick for forcing signals through systems - problem is, there is not a low cost option to do everything we wanted to do.
The current flavor for 4K is H.265 which is twice as efficient as H.264 (uses 1/2 the bandwidth) - H.265 is what Netflix uses - the proof is in the pudding - a full resolution 4K image on Netflix may be softer, and often times is softer than an image produced from a 1080P blu ray player. Why? Bandwidth - the blu ray is running at about 36 MBP/sec and your home internet speed is at best in the USA is around 10 MBP/sec thus the blu ray player has almost 4 times the bandwidth. MPEG compresses files enough to get through the available pipeline to your TV - thus higher speeds (bandwidth) results in better picture quality and experience.
Another way to prove this out is via off-air UHF antenna - that picture is crisper and higher definition than the one from your cable or satellite provider because of the FCCs mandated 19.2 MBP/s requirement vs. under 10 MBP/s - DSL is even lower at 5 MBP/s.
The new blu-ray player is said to be 100+ MBP/s and will likely be (I'm speculating now) 2160P24 4:4:4 10-bit to match films frame rate - although there is a camp that is saying it will be 2160P60 4:2:2 10-bit. In some commercial applications, and for obvious reasons, no compression is a must - engineering, simulation, graphics/CGI, etc.
We'll cover chroma sub-sampling and bit depth in the next article - chroma sub-sampling saves bandwidth and increased bit-depth uses more...
Part 4 of 4 ~ 4K UHD Field Testing Headaches
So this is what we did - not real scientific - because we expected that everything would just work as described in manuals, specifications, etc. you have probably done the same thing and got downright frustrated with the process - it's like troubleshooting, which I have done for a long time - divide and conquer - replace potential defective components with known good components...unfortunately at this point in time the cards are stacked against you as an integrator, which to be honest presents a great opportunity to be ahead of the curve and become a trusted adviser to your customer.
What every integrator needs today is knowledge - we will strive to bring you that knowledge - what every integrator also needs is a tool to provide known good signals up to 2160P60 4:4:4 with HDCP 2.2 for validation that the systems they install will work and meet the customers application and requirements and don't waste time.
Opportunity knocks - this IS the next big thing.