ATSC 3.0 Framers To Choose HDR Technical Solution by July 31, Conference Told

S34-1 hasn’t decided whether to go with a single HDR technology or with “multiple” solutions, Stein said. The selection will follow a “comparative demonstration” mid-June in New York of the “several proposals” now before S34-1, he said. Though ATSC 3.0 video was elevated to the status of candidate standard in December without HDR included (see 1505130058), “we believe that we can add HDR capability during our candidate standard period,” which expires July 31, Stein said. “We are in an evaluation period right now. We have several proposals.”

Though the proposals have “common elements,” each “approaches the HDR problem a little differently,” Stein told the conference. In all, there are six HDR proposals before S34-1, Stein told us later, adding he wasn't sure if he was at liberty to identify them publicly. The comparative HDR demonstration on the various proposals will take place the week of June 20 at the CBS lab in New York, he told us. The CBS lab recently acquired two 1,000-nit professional monitors for HDR testing, Robert Seidel, chief technical guru at CBS, told the recent NAB Show (see 1604200018).

One of the reasons HDR and wide color gamut are “so compelling is that they offer a significantly improved user experience -- higher contrast, brighter or deeper colors -- for a relatively minor increase in the bandwidth required to deliver them,” Stein said. Though it takes three times the bits to upgrade to 4K over full HD, the upgrade to HDR from standard dynamic range takes only a 15-20 percent increase in the bandwidth “that’s required to support that,” he said.

The monthslong “process” to choose an ATSC 3.0 audio codec was “intense,” said Jim Starzynski, director and principal audio engineer at NBCUniversal Advanced Engineering and chairman of the S34-2 audio ad hoc group. The three-part A/342 document on ATSC 3.0 audio was elevated to candidate-standard status only last week after long delays (see 1605040050). “We went back and forth on many things, and we found that business decisions certainly do play really heavily in the ATSC process, there’s no question there. But, of course, we married them with the technical needs, and we were able to make progress and get to a result, so all that was terrific.” Of the decision documenting both Dolby AC-4 and MPEG-H as ATSC 3.0 audio codecs with the recommendation that AC-4 be used in the U.S., Starzynski said: “This is great, because I get to say, two technologies are in candidate standard now."

Broadcasters need ATSC 3.0 because “the media landscape is changing,” said Dave Siegler, vice president-technical operations at Cox Media Group. “It’s still undergoing a massive change where we need to adapt, and we need to catch up,” he said. “I think we’re a little bit behind, but with the new standard, we can catch up and surpass some of the delivery systems out there today.”

The future of TV “is already upon us, with multiple devices, multiple consumption changes, and we have to simply adapt and get better,” said Siegler. For example, “Ultra HD change is underway,” he said. “This is happening around us, not with us yet. We need to really be there to provide that platform to get this content distributed out to consumers, who are demanding higher-quality content.”

Progress on ATSC 3.0 is based on the “very extensive body of work” that was developed by “thousands of engineers around the world,” said ATSC President Mark Richer. Day One of the two-day broadcast TV conference in recent years was called the ATSC 3.0 “boot camp,” Richer said. However, the theme of this year’s Day One event, “Planning Your ATSC 3.0 Rollout,” was so renamed to give broadcasters technical advice on the “practical implementation” of the system, now that ATSC 3.0 is progressing toward a suite of final standards expected to be finished before ATSC convenes its next annual broadcast conference in May 2017, Richer said.

Rich Chernock, chief science officer at Triveni Digital, echoed Richer when he said the aim of this year’s conference was to put less emphasis than in the past on “bits and bytes,” but more on the “practical aspects” of the various components of ATSC 3.0's “protocol stack.” Most of those components have reached the status of candidate standard, which symbolizes the functional equivalent of “where we think we got it right,” said Chernock, who chairs ATSC’s Technology Group 3, which supervises all ATSC 3.0 framing activities.

ATSC members approved elevating A/322, the second ingredient of ATSC 3.0's physical layer, to the status of proposed standard after balloting that was completed Friday, said Mark Earnshaw, senior systems architect at Coherent Logix. The A/322 physical-layer protocol document contains virtually all the components of ATSC 3.0's physical layer that aren't contained in the A/321 bootstrap, which in March became the first ATSC 3.0 ingredient to reach the status of final standard (see 1603280043), he said.

The use of “hierarchical control signaling” in the physical layer “provides a robust, yet efficient form of communicating” the physical layer’s various “waveform configurations” to an ATSC 3.0 receiver, Earnshaw said. “The fact that we are able to use a combination of multiple, different operating points” in the physical layer allows for a wide signal-to-noise range, and the ability to “address different types of receivers with different robustness requirements,” he said. “Different services with different robustness requirements can be multiplexed together into the same physical-layer transmission.” ATSC’s S32 specialist group on ATSC 3.0's physical layer has begun work on a “recommended practices” document “that will provide guidance about how to set up all the possible configurations” of ATSC 3.0, “and make optimal use of the technologies that are available,” he said.

Sony Electronics Senior Staff Engineer Luke Fay, who chairs S32, described the physical layer as the “meat” of ATSC 3.0. For questions about ATSC 3.0 “receiver profiles,” ATSC will “refer” those to CTA, which has a “working group that is looking into that right now,” Fay later said in Q&A, responding to a question about ATSC 3.0 receiver implementation. ATSC “is basically a broadcaster forum, and we’re maxing out the options for the broadcaster within the standard,” said Fay. “And that’s our main purpose here, is to allow the broadcaster as many options as possible for that. Receivers are in a different organization at this time, but they know about the ATSC work.”

The CTA working group to which Fay referred “is currently focusing on guidance for the industry related to ATSC 3.0 video profiles,” Dave Wilson, CTA vice president-technology and standards, emailed us Tuesday. “While the group can’t yet predict a completion date, it does intend to complete its work as quickly as possible. Once the work on video profiles is complete, the working group may consider other aspects of ATSC 3.0.”