HDMI 2.0: What's in It for Pro AV?


Type: Article, Report or Whitepaper

Topics: AV Equipment; Digital Signage; Video

Date: February 2014

By Tim Kridel, Special to InfoComm International® 

HDMI has a rep for being a consumer-oriented technology, right down to the perpetual lack of a locking connector. So what does the 2.0 version, which debuted in September 2013, have for pro AV?
Plenty, it turns out. Examples include support for high-frame-rate 4K, a 21:9 aspect ratio to enable wide-angle content, and a dual view feature that can cut the number of cable runs in half for some installations.
“Although some of the new features are intended for professional use, the home run is definitely 4K with 50/60 frame rate capability,” says Ron Wysong, R.L. Drake product and market development research manager. “The existing HDMI 1.4b standard is capable of handling 4K TV resolution at 24 and 30 fps as provided by content made for theaters (24 fps is available on Blu-ray disc).
“But only HDMI 2.0 and its 18 Gbps speed can handle 4K TV content produced at 50 or 60 fps and a 10- or 12-bit color depth. This higher frame rate and color depth are required to provide the true 'spatial experience' that 4K UHDTV is capable of delivering.”

Any discussion of a new spec inevitably comes around to how it stacks up against other AV and IT standards. In HDMI’s case, those include DisplayPort and DVI.

“For professional applications, a wide range of supported PC resolutions is an added benefit [of 2.0],” says Teemu Nivala, Gefen vice president of product development. “Now HDMI can be used for all applications previously requiring dual-link DVI or DisplayPort.”

HDMI 1.4 supports up to 10.2 Gbps. Although 2.0 nearly doubles that, there’s still some concern about whether that’s fast enough.

“There seems to be a lot of hand wringing over HDMI 2.0 as many believe it does not go far enough to support display needs in the next few years: that [its] data rate is limited and other approaches are a bit higher, [such as] DisplayPort at 21 Gbps,” says Chris Chinnock, Insight Media president and founder.

When it comes to connectivity standards, the pro-AV industry often follows the IT industry’s lead because signage and projectors frequently are driven by PCs.

“For a while HDMI had a stronghold in the laptop business, but now DisplayPort is making a comeback,” says Dave Silberstein, Creston director of commercial marketing. “Part of it is because it’s got that [21.6] Gig channel, and part of it is that there are other advantages within the laptop environment.”

Most pro-AV applications top out at 1080p, but PCs and tablets have started exceeding that. HDMI 2.0 gives pro AV another way to support 4K at high frame rates.

“We need to expand to at least the 4K space to address the laptops and tablets that are going to be in the marketplace for the next couple of years,” Silberstein says. “Once we start using [4K] on our desktop, we’re going to expect it in our conference room.” 

Seeing double

Some AV pros like HDMI 2.0’s streaming capabilities. 

“It not only has the ability to simultaneously deliver dual video streams to multiple users on the same screen, but it also enables multi-stream audio to multiple users,” says Michael DiBella, Atlona marketing communications manager. “Knowing that HDMI 2.0 is at the forefront of streaming delivery will be reassuring for system designers as streaming becomes more widely used as the preferred method for content distribution.”

Streaming also is an example of how some HDMI 2.0 features have potential pro applications that aren’t immediately obvious. Dual view was designed to allow a single source – such as a cable box – to send multiple video streams to a display for rendering in 3D.
“That was the original intent,” says Jeff Park, HDMI Licensing technology evangelist. “However, one other practical way of using it is to reduce cable runs.”

Imagine a bar with two displays fed by a single source in a back room. One option is to pull a long cable to each one. With dual view, a single cable could be used for most of the run. Near the displays, a splitter would divide the streams and send them the rest of the way over two short HDMI cables.

That architecture could be beneficial if, for example, the bar is in a city where codes or labor laws require an electrician to pull those cables. If the electrician charges by the run, then dual view cuts that labor cost in half.

“So there are some clever ways of using the technology other than the way it was designed,” Park says.

Content wild cards

As 4K content becomes more common, it’s important to understand what each version of HDMI can handle. That’s because “4K” has become a catchall term spanning 30 to 60 fps.

“So consumers and integrators are going to need to be very careful because everybody is going to say 4K, but there are so many flavors that they’re going to have to look at the spec,” says Steve Venuti, HDMI Licensing president.

Things can get tricky when, for example, a commercial installation winds up using consumer 4K TVs after the client had sticker shock with pro 4K displays. Those TVs might not be able to support 50/60, and that would be an issue if the application requires that frame rate.

“HDMI 1.4b can handle 4K TV just fine up to 30 fps,” says Drake’s Wysong. “However, HDMI 2.0 is required for 60 fps, and such content will not be readily available for some time.”

Content protection is another factor. HDMI 2.0 uses HDCP 2.2, which uses a different technology than HDCP 1.x and isn’t backward compatible.

“The folks in Hollywood have said – although I don’t know if it’s going to happen or when – that their 4K content is not going to be released unless HDCP 2.2 is deployed,” Venuti says.

The bottom line is that when projects involve premium content, it’s important to be aware of where HDMI 2.0 and HDCP 2.2 fit in.

“This can be an additional challenge and concern for integrators in the near future,” says Gefen’s Nivala. But for now, there are no devices in the market supporting HDCP 2.2, so the level of the challenge remains to be seen.”

Products coming soon

Sometime this summer, pro-AV vendors should be able to start sourcing 2.0 chips in volume.

“As a manufacturer, are we doing 2.0? Absolutely. We’re all over it,” says Crestron’s Silberstein. “But there’s nothing in the marketplace. The only people who have anything are people who build their silicon: the Sonys of the world.”

It’s up to each vendor to decide whether to provide a firmware upgrade to bring its 1.X products in the field up to 2.X. The decision depends on factors such as whether a particular piece of hardware has a chipset capable of handling 2.0’s additional workload.

“Most HDMI 2.0 firmware upgrade products will only do a partial feature set of HDMI 2.0,” says Gefen’s Nivala. “The hardware has limited bandwidth, and firmware upgrades will not change that.” 

Creston designs its HDMI products using field-programmable gate arrays (FPGAs), along with extra memory headroom, a combination that provides a certain amount of future proofing.

“We always look for our chip vendors to have those kinds of features available to us,” Silberstein says.  

Gefen also tries to provide upgrades as often as possible.

“We aim to upgrade all products that have chipsets that allow adding HDMI 2.0 features,” Nivala says. “We achieved this when 3D came out with HDMI 1.4, and we plan to replicate this with HDMI 2.0. These upgrades will be launched throughout 2014 when validation tools become available and new HDMI 2.0 devices start to hit the market.

“We predict most common firmware upgrade features to be supported for 4K resolution with a 60Hz refresh rate and reduced 4:2:0 color depth, which is needed to support 4K 60Hz with 300 MHz bandwidth available with HDMI 1.4 chips.”

A device’s lifecycle is yet another factor. For example, upgradeability to 2.0 probably would be a non-issue for owners of digital signage deployed in, say, 2011 because that gear is nearing the end of its useful life anyway. As for HDMI itself, considering how many vendors are set to ramp up production later this year, the technology probably will be a staple in pro AV for the foreseeable future.

What’s your take on HDMI 2.0? For example, does the new version make HDMI a better fit for pro-AV applications than 1.4? If you could change anything about HDMI, what would it be? Weigh in at InfoComm’s LinkedIn discussion group.