DTV Audio Group Readies for ‘Period of Intense Change’

DTV Audio Group Executive Director Roger Charlesworth’s opening remarks for the organization’s Oct. 30 event, co-located with the AES Show at New York’s Javits Convention Center, applied equally to the agenda at hand and to the group’s larger purpose. “We set out to create a conversation,” he said, “one that would help content creators and distributors prepare for a period of intense change.”

12-8-DTVagPG800It was a conversation that began nearly a decade ago and has led to novel education and training initiatives and to an ongoing advocacy for professional users of wireless microphones as broadcasting prepares to undergo yet another wrenching round of spectrum loss. Most recently, it has been about the next major inflection point in multichannel audio, which will see it migrate from channel-based to object-based configurations.

The DTV Audio Group — through a working group made of DTVAG member manufacturers, network users, and service providers — has been highly proactive regarding decisions made by the FCC on spectrum reallocation. That high level of participation is warranted, according to Charlesworth.

“We secured a small amount of additional spectrum to make up for the huge chunk of 600 MHz we are losing, but it isn’t nearly enough. If we don’t ask for additional replacement spectrum now, we won’t be able to ask later,” he said, underlining how megacorporation lobbying and government decision-making could leave the relatively small but critical niche of wireless operations hemmed in.

During the meeting, representative presenters from network sports divisions, technology developers, and product manufacturers outlined where object-based audio, a foundational aspect of the forthcoming ATSC 3.0 standard, stands at the moment.

Administratively, although no final decisions have been announced on key issues, such as the choice of audio format as the successor to the current AC-3, the ATSC S34-2 working group has completed testing of proponent systems. A decision on the eventual audio format is expected this year, with the completed ATSC 3.0 standard likely to be announced in 2017, with implementation to take place the following year.

MVPDs and content distributors are not waiting for a new over-the-air standard to begin implementing next-generation audio services, and the group heard from members on implementation of advanced features and encoding technologies currently being rolled out for streamed direct-to-consumer delivery and by advanced cable and satellite services on fixed and mobile devices.

Although immersive experiences are an important feature of next-generation audio systems, enhanced accessibility, bandwidth efficiency and personalization are considered the fundamental drivers. Presenters stressed that personalization will be key to new services. In addition to providing improved video description and the ability to let viewers choose multiple languages with full multichannel audio presentations, consumers will have a number of ways to customize broadcast audio to enhance intelligibility or tailor experiences to individual tastes, with content creators defining presets and degrees of customization allowed and a reset feature to return to baseline any parameters changed. Sources of personalized content would be far wider as television integrates more deeply with the Internet: the radio broadcast from the away team’s hometown could, for instance, be used to supplant the announcer channel of a national sports broadcast.

By way of example of personalization in action, the group passed around an Android tablet with a Dolby AC4-based app and content provided by various DTVAG members demonstrating personalization and accessibility features being prepared for rollout.

Attendees also learned that next-generation audio codecs will be considerably more efficient. Today, 5.1-surround audio in AC3 transfers at 384 kbps to the broadcast encoder before going to the transmitter, with a second mono SAP track adding 192 kbps. Next-generation codecs, such as Dolby’s AC4 and Fraunhofer’s version of MPEG-H, will be able to use the same 384 kbps to carry a 7.1+4 (seven LCR and surround channels, an LFE channel, and up to four auxiliary objects, such as alternate languages) configuration. This will also include the metadata needed to operate personalization features.

Context
Beyond the technical side of broadcast audio’s ongoing evolution, presenters noted that the context surrounding the industry is changing. Cord-cutters and cord-nevers — millennials who bypass conventional television distribution and watch its content via YouTube and other Internet and mobile sources — have disrupted the industry, lowering revenues and clouding expectations.

“Apps like Periscope and Meerkat make every mobile device a broadcaster,” observed Tom Sahara, VP, operations and technology, Turner Sports, delivering the event’s keynote address. “Apps have created expectations of instant results. Winter X Games generated 30 million views of user-generated content in 24 hours. It’s what consumers have come to expect.”

In less than three years, broadcast audio will have undergone a set of changes more radical than the transitions from mono to stereo to surround, and it will have done so within a dramatically disrupted economic and spectral environment. This year’s DTV Audio Group meeting was a moment to review what has been accomplished and to anticipate what is still to come.

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