LTS 2011: DTV Audio Workshop Touches All the Bases of Digital Workflow

By the time the SVG League Technology Summit’s audio workshop got under way on Dec. 12, more than 50 attendees were ready to hear ideas on how to streamline audio production in a field that continues to move deeper into digital, with more embedded audio, more MADI, and more legislative challenges.

Turner Sports' Tom Sahara discusses legislative issues affecting sports-broadcast audio.

Tom Sahara, VP of operations and technology for Turner Sports, took on the legislative issue and more in the first presentation of the afternoon. In “Harmonizing Audio Deliverable Standards in the Age of Multiplatform Delivery,” he reprised some of what he had presented at the AES Show in November, pointing out that sports-broadcast content is going to have to adapt to being distributed to and consumed on personal mobile devices. “It’s going to have to scale from big home-theater screens with 5.1 speaker configurations to 2-in. screens with earbuds,” he said. “It’s going to be a wide variety of experiences [for the same content].”

He pointed out that the ATSC A/53 digital-television standard was written to address a home-viewing environment that was essentially noise-free and passive, in which viewers watched long-form programming in a linear fashion with an emphasis on sonic fidelity and high resolution. Mobile devices turn that environment on its head: they’re implicitly noisy, and small screens compel short-duration viewing of many channels of content, often with challenging streaming-connectivity issues that make linearity elusive, which further contributes to the brevity of the content.

“Convenience, rather than intelligibility, is paramount,” he said.

Sahara pointed out that mobile devices like phones increasingly have HDMI and other high-definition CE-type ports and thus can be interfaced with docks that can provide higher-quality sound and picture reproduction. The bottom line, he said, is that content’s “new paradigm” will consist of multiple devices and multiple formats for the same content and that content will cross multiple boundaries between those devices and formats, which argues for as much standardization and consistency as possible as soon as possible. In a scenario in which compatibility between such devices as Apple TV and Google TV and formats like Roku and Boxee cannot be guaranteed, metadata is going to have to be the basis for consistency in the distribution of content.

Information About the Content
Metadata will also be the foundation of addressing the tenets of the 21st Century Communications & Video Accessibility Act, which mandates closed captioning for broadcast content that is also distributed via IP channels, something Sahara called “a game changer” for broadcast audio even though the legislation exempts most live sports coverage. Metadata components that will need to be incorporated include content information, such as dates and times; audio track layouts; rights-management information; and even social-media tags. Noting that significant work on creating a consistent metadata format has already been done, he cited the Advanced Media Workflow Association (AMWA) AS-03 MXF Program Delivery Specification, a vendor-neutral subset of the MXF file format to use for delivery of finished programming from program producers and program distributors to broadcast stations. AS-03 files contain defined sets of metadata for identification of content and for verification of content versus program-traffic metadata that is delivered separately.

“We’re not starting from scratch with this,” he said. “There are beacons of light we can follow.”

Toward All-Digital Trucks
The panel “Evolving Production Infrastructure” addressed such issues as high-density routing, digital-console design, and 5.1-audio-monitoring environments aboard remote-production vehicles. Moderator and DTV Audio Group Director Roger Charlesworth raised key issues, including whether the truck can be digital-only going forward and why MADI is important.

ESPN Coordinating Technical Manager Henry Rousseau said his network is already contemplating the “truck of the future,” noting that it will be a combination of in-house engineering and collaboration with truck builders and equipment manufacturers. Technical goals include elimination of analog patch cords in favor of completely digital signal routing via integrated router/console combination, and the use of MADI to transport signals between trucks and other points.

He also addressed a key point for U.S. broadcasters: that any new truck configurations have to be easily accessible to the mainly freelance pool of A1s that U.S. networks rely on. “The GUI has to be easily understood by operators. If there is a degree of difficulty to program routers, that can take time away from preproduction.”

Felix Krueckels, senior product manager at German console manufacturer Lawo, pointed out that European broadcasters made the transition to HD-audio-signal routing some time ago. The main advantage it confers, he said, is that, although programming a truck’s router can be time-consuming, once it’s accomplished, users can create “base files,” templates that adjust the basic router settings for various sports applications and can do so in a matter of seconds from hard drives or flash drives that A1s take with them to hold custom settings.

A1 Peteris Saltans seconded a desire to eliminate as much copper from trucks as possible, although he cautioned that some analog technology would be still needed as a backup. “I’d like to see it be in the digital domain as much as possible,” he said. “It would be great to be able to preplan [a setup] while you’re still on the road,” as opposed to waiting until the mixer is on-site.

Kurt Heitmann, VP of sales and marketing for CP Communications, said he’s sold on the idea of the all-digital truck, calling the necessary workflow adjustments “mental engineering” as A1s migrate to a plug-and-play environment. “People will still need to patch, but, as you’re patching, you’re building a file that you won’t have to build again every time.”

The number of channels available using onboard routers can seem mind-boggling compared with analog routing, numbering into the thousands. However, as Kevin Cleary, senior technical audio producer for ESPN Event Operations, pointed out, even that many channels are quickly reduced when all audio is in the six-channel 5.1 discrete configuration.

“That gets a 1,024-channel router down to about 170 channels pretty fast,” he said, after a quick mental calculation.

Consoles and Control
It also raises issues of control over that many channels of audio, which leads to console-work-surface design, which favors the multi-layered approach that most manufacturers are now applying to their products. Rousseau noted that the most recent trucks designed for ESPN feature Calrecs fitted with 144-fader desks. He also said that all-digital trucks will need to develop some kind of standard for intertruck connections.

Heitmann quickly pointed out that MADI already achieves that purpose and that all the major router and console manufacturers can already implement it, although he acknowledged that a better interface needs to be developed. Jason Taubman, VP of design and new technology at Game Creek Video, described MADI as “skinny. I’d like to see a high-density solution developed.”

The remaining two panels, “Going Native: Discrete 5.1 Workflows and Acquisition Techniques for Live Production” and “Making the Case for Single-Unit Surround Microphones,” had some understandable overlap. Charlesworth pointed out that single-point surround microphones of the type offered by Holophone, Sanken, and Soundfield feature a single-point connector, in the form of the X-189, for camera mounting; also, their patterns and capsule configurations can be remotely adjusted to accommodate changing game conditions and can be automatically decoded on the console. Implementation of more 5.1 microphones on sports shows would increase the amount of native 5.1 signal in the workflow.

What To Do With All the Info
The barriers, most agreed, were cost and adjusting the workflow to accommodate all of that new multichannel information. As ESPN’s Cleary said, “When you’re facing over 3,000 entertainment shows a year, plus thousands of pieces inside the [Bristol, CT, headquarters] building’s router, you have to go the board of directors level about, ‘Will there be discrete 5.1 for every piece?’”

Jay Yeary, director of audio and studio engineering for Turner, drew some laughter when he pointed out that, while audio at flagship net TNT is discrete 5.1, the parent company still has subsidiaries in Latin America that are only now considering upgrading their audio to stereo and that only three of the 17 audio rooms at Turner’s main studios in Atlanta are fitted for discrete-5.1 monitoring.

The consensus seemed to be that, while single-point surround microphones can now bring a new perspective to sports audio, their costs — as much as $12,000 for a single unit — are daunting, even for large networks struggling to budget for more and more hours of sports. Also, the vast amount of additional data they would bring could strain existing audio infrastructure.

Pieter Schillebeeckx, R&D director for Soundfield, gamely called single-point surround microphones “the new glue” for sound for large sports broadcasts, creating a consistent foundation for more specific effects to lay over. Bob Dixon, director of sound design and communications for NBC Olympics, said he’d love to see surround mics become more ubiquitous. For the immediate future, though, their use will likely be relatively sparse, and A1s will continue to rely on the combinations of mono and stereo shotgun mics that now make up most of the surround fields for broadcast sports.

Cleary stated that he has no problem with upmixing natural sound to 5.1 for the surrounds. Mixing his metaphors, he added, “If I had to put a $12,000 microphone on 18 greens [for golf], that’s a whole different ballgame.”

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