NAB Show To Tackle Next-Gen TV Audio

Like TV broadcasters themselves, audio for television at the 2017 NAB Show will find itself with one foot planted in a present where the issues of audio over IP and the allocation of spectrum for wireless mic use impact daily operations, and the other finding terra firma for what’s to come as ATSC 3.0 nears completion and new audio concerns like immersive and personalized sound arise.

“AC-4 has come a long, long way,” says Jeff Riedmiller, VP of the sound group in the office of the CTO at Dolby Laboratories. “We started this thing five years ago with a blank sheet of paper and to come this far is really encouraging.”

Last week, the Advanced Television Systems Committee published the Dolby AC-4 next-gen audio codec specification, A/342 Part 2, as a complete standard in the suite of next-gen television standards making up ATSC 3.0, he says.

At about the same time, the FCC announced it was adopting a Notice of Proposed Rulemaking aimed ultimately at authorizing broadcasters to begin ATSC 3.0 operations on a voluntary basis.

Together, the actions add urgency for U.S. broadcasters attending this year’s NAB Show (April 22-27 in Las Vegas) to get serious about tackling object-based audio, which enables ATSC 3.0 features like immersive sound and personalized audio.

“A big focus of a lot of our discussions in recent years has been object audio,” says Roger Charlesworth, executive director of the DTV Audio Group.

However, many of the opportunities for object-based audio to shine have until recently been limited to Dolby Atmos-cinema presentations and premium episodic content carried by some MVPDs like Comcast.

“We are starting to see object audio production in live television, for instance in Premier League soccer in the U.K.,” he says.

The DTV Audio Group, which will hold its annual audio-for-live TV forum in association with the Sports Video Group at the Alexis Park Hotel in Las Vegas on April 23, will make object-based audio mixing in a live TV production a major theme of the meeting, says Charlesworth, who adds that attendance is not confined to group or SVG members.

Public broadcasters also will tackle day-to-day AC-4 operations during a presentation at the PBS TechCon leading up to the NAB Show, says Dolby’s Riedmiller.

Mike Babbitt, the company’s solutions engineering director, will present “A Broadcaster’s Guide to the AC-4 Audio System for Broadcast & OTT” at the event, which takes place April 19-21 at Caesars Palace in Las Vegas.

On the NAB Show exhibit floor, AC-4 not only will be featured prominently in the Dolby booth, but also will be highlighted in the booths of companies including Harmonic, Ericsson and others that are supporting AC-4 with new features and products, says Riedmiller.

The NAB Show once again will devote a special exhibit area to the consumer experience viewers will have with ATSC 3.0.

Immersive audio and personalized sound will be an important part of the area, which this year is called the Next-Gen TV Hub and is located in the Central Hall of the Las Vegas Convention Center.

All ATSC 3.0 audio isn’t AC-4 centric, however. The standard allows broadcasters to select on a regional basis whether to use AC-4, which the North American Broadcasters Association has approved for the United States, Canada and Mexico, or MPEG-H as their audio system.

(Note: Click here to access TVNewsCheck’s NAB 2017 Resource Guide listing of audio-for-TV vendors and products.)

In South Korea, MPEG-H is the audio codec of choice for ATSC 3.0 broadcasting, and at the NAB Show German technology research institute Fraunhofer, a leading MPEG-H proponent, will be showing the maturing ecosystem of MPEG-H broadcast and consumer products, says Robert Bleidt, division general manager of Fraunhofer USA Digital Media Technologies.

ATSC 3.0 TV sets go on sale this month in South Korea as that nation’s broadcasters target May for the launch of regular next-gen TV service in preparation for OTA delivery of the 2018 Winter Olympics from the peninsula in 4K, he says.

3.0 sets with MPEG-H support will be a part of the Fraunhofer NAB Show exhibit, although Bleidt could not yet specify brands.

As 3.0, an IP-based broadcast standard, nears completion, the Society of Motion Picture and Television Engineers is at work on other IP media standards related to timing and professional video and audio transport. Those efforts are having an effect on audio,

“We are seeing the standardization around IP video, and that is having a really positive impact on audio because it draws into it the standardization of audio as well,” says DTV Audio Group’s Charlesworth.

While audio over IP has grown in importance in the marketplace for several years, it is the momentum behind the SMPTE ST-2110 professional video IP standard, which references a specific implementation of the AES67 IP protocol for audio transport, “that is allowing vendors to implement AES67 in a standardized way,” he says.

While proprietary audio over IP protocols, such as Dante, Livewire, Ravenna and WheatNet-IP, will be featured in vendor booths throughout the exhibit halls at the NAB Show, it is AES67 that will provide the glue to bring together technologies from competing vendors using disparate IP transport protocols, says Josh Rush, VP of marketing at Audinate.

“AES67 is the lowest common denominator in the broadcast world,” he says, adding that was what motivated Audinate to add support for the protocol last year. “It’s a baseline way to connect audio streams,” he says, but it is not a complete audio networking solution.”

Phil Owens, who works in sales at audio console and networking vendor Wheatstone, echoes Rush’s comments. “The thing that needs to be understood about AES67 is that it is a transport protocol for audio only — that it is does not include other audio-over-IP aspects like control and discovery,” he says.

At the NAB Show, Owens says AES67 will continue to play a supporting role enabling hybrid audio-over-IP-based applications in which the core is built on a vertically integrated system, such as one using WheatNet IP, which incorporates control, discovery and transport, and then interfaces with external devices via AES67.

IP transport of audio may also help to drive the related NAB Show audio trend of remote production, using a central production control room rather than remote trucks, Owens adds.

The other big audio issue facing broadcasters at NAB is what to do about wireless mics, a catch-all term that includes a variety of audio gear such as in-ear monitors, mics and IFB.

Now that the FCC spectrum auction is completed and 600 MHz TV spectrum used by wireless mic gear will soon be a distant memory, television broadcasters relying on the wireless equipment for everything from production of sports and entertainment to ENG shots from the field must find an alternative.

At least as of this writing, vendors are playing their cards close to their vests about replacement products they may be showing in Las Vegas.

In the view of the DTV Audio Group’s Charlesworth, there may be some products at NAB that enable what remains of the UHF band for wireless mic use to be packed more densely.

However, the ultimate solution is more likely to entail entirely new technologies, such as spread spectrum, in new bands like 6 or 7 GHz, he says.

“In terms of newsgathering, I don’t know what they will be because we haven’t yet seen them. I think we will, but I don’t see them coming that quickly,” Charlesworth says.

Click here to access TVNewsCheck’s NAB 2017 Resource Guide listing of audio-for-TV vendors and products or click here to download it as a PDF.

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