M+E Connections

Dolby, Elemental Execs: HDR Making Major Strides, But Challenges Remain

High dynamic range (HDR) continues to make significant strides on multiple fronts, but challenges remain, according to executives at Dolby Laboratories and Amazon Web Services division Elemental, a supplier of software-defined video solutions for multi-screen content delivery.

After all, there’s still multiple formats and standards, as well as single- and dual-layer implementations, and a growing array of display options, they pointed out Dec. 8 in an Elemental-sponsored webcast called “Mapping the Future of Video with High Dynamic Range.”

While the “baseline standards are basically done” for HDR, the “application standards are in the works, especially in broadcast,” Roland Vlaicu, VP of multi-screen services video at Dolby, said. There is a “standardization effort under way” in China and “we’re participating in those, trying to get these broadcasters and the groups to understand … the benefit of starting with a generic HDR experience that allows you to have static metadata” and HDR 10, but also then “allowing the option for enhancing through dynamic metadata to enable the best possible experience down the road,” he said.

Metadata plays an important role in HDR workflow, said Mike Callahan, Elemental senior director of solutions marketing, explaining that “it’s required to be able to tell the display that the signal has something unique or explains some of the properties around the signal that the display is receiving.”

Depending on the HDR being used, the metadata is either dynamic or static. In the static case, the metadata is “defined once per asset and that asset has the exact same metadata applied” for the entire film, TV show episode or other piece of content, Callahan said. Dynamic metadata “changes depending on the implementation type, but typically is either scene-based or frame-based,” he said.

There are, however, some challenges with HDR metadata, Callahan said, pointing as an example to the fact that “there isn’t really a standard location for where the metadata goes.” Proposals include “layering it with multiple video elements” or including it in the transport layer, he said, but added: “It’s a little bit up in the air right now which of these is going to be the most robust for production workflow, and that changes depending on the type of video that we’re delivering — whether it’s live or VOD, for example.”

There’s still no clear indication that a single approach to HDR will be agreed upon in the near term by all companies involved in the ecosystem.

That’s why Dolby “took an ecosystem perspective from day one,” Vlaicu said, explaining: “Making high dynamic range work isn’t going to happen if you only focus on the TV or if you only focus on the camera. You have to really focus on everything in between” also. Therefore, Dolby spent a lot of time “enabling the entire chain,” by working with camera and TV makers, content creators, post-production facilities, encoding and distribution companies, and the companies that make the chips that go into TVs and other devices, he said, adding: “What is important is to understand that everybody needs to be able to benefit from this activity. So, in order to make HDR work, everybody needs to win.”

Pointing to the strides that the VOD market, in particular, has made with HDR, Vlaicu said: “We are now at a point where … the video on demand workflow is established, so we have the necessary tools in place, where Hollywood and Netflix and Amazon, etcetera, are creating content at the highest level of standard, which is Dolby Vision.”

Most of the Hollywood studios, meanwhile, have started mastering their content in HDR, and that’s become “their standard way of doing things now,” Callahan said. As a result, he said, “there’s been a lot of progress on this kind of front half of the workflow, especially on content creation, and then that’s slowly moving its way through the chain and not only the playback device, like Ultra HD players, but also to the streaming video providers.”

Companies including Amazon, Netflix and Vudu have “taken the lead essentially on this new type of content, and part of it is because they have a distribution platform that’s very flexible when it comes to the Internet,” and makes it easy for them to make HDR and standard-definition versions of the same content available to consumers side by side, he said.

On the other hand, pay TV distributors haven’t been so fast to fully jump on the HDR bandwagon with sports and other live content, Callahan said, adding they’re still “in the middle of working out what those tool chains look like.” On a positive note, he said with a laugh: “We’re not talking about years out. We’re talking very, very soon we’ll start seeing live productions” in HDR. He predicted it will happen in a way similar to the way it did with VOD, with a small amount of live broadcasts in HDR and then “we’ll start to gain momentum.” Elemental has already done some “proof of concepts” with those companies, he said.

An increasing number of HDR-capable TVs, meanwhile, are reaching the market, including TVs featuring Dolby Vision from LG and Vizio, Vlaicu said, adding the consumer electronics industry is “embracing” HDR. “After the failure of 3D in the home, there was really the desire for a new feature,” and Ultra High-Def (UHD)/4K “on its own didn’t really quite cut it because the immediate consumer benefit wasn’t as visible,” he said, but added the combination of UHD and High Dynamic Range should convince consumers — especially if they see it for themselves.

Meanwhile, not all content is going to have to be UHD to take advantage of HDR, Vlaicu went on to say, adding: “A lot of broadcasters that I’m talking to have the intent to — especially for live production — actually combine HD with HDR because that gives you a unique value proposition.” That’s a cheaper alternative than broadcasting live HDR content that is also UHD and “there’s definitely a path for that,” he said.

Similarly, Callahan predicted that there will be a growing number of HD and UHD devices, including mobile phones, that support HDR — although he predicted there will probably not be HD TVs that support HDR. Agreeing, Vlaicu said the rapidly declining pricing of TV panels and rapid adoption of UHD TVs provide little economic incentive for TV makers to make HD-only HDR TVs.