Immersive audio continues to grow in popularity among content creators and consumers, buoyed by a growing selection of devices for playback in the home or on the go. But while post-produced immersive audio is now well supported by tools and technology, products with a full complement of features and functionality to generate live broadcast content are still relatively scarce.
To be sure, there are already examples of live broadcasts incorporating immersive audio to be found globally, particularly in sports programming. And immersive audio capabilities have been written into the next generation of television standards worldwide. What features are equipment manufacturers considering to meet the challenges in the broadcast market? And when might we be able to regularly experience more live immersive broadcast content?
Wheatstone senior sales engineer Phil Owens believes that it will be some time before immersive audio is commonplace in broadcast television. “Immersive audio at the console end requires two things: more console bus outputs and the ability to pan in 3D. The z aspect—height—has to be added to the panning algorithms,” he says. “It’s definitely a must for the mixing of films, but I don’t think you’ll be seeing immersive audio in your 6 o’clock news anytime soon.”
Larry Schindel, senior product manager for Linear Acoustic, says that, just as 5.1 surround arrived married to HD video 20 years ago during the digital broadcast transition, immersive audio will likely be wed to 4K picture. Consequently, he says, “Products that support immersive audio will need to be prepared for not only the additional audio channels and processing, but for the greater video requirements that will come along with this.”
As the industry transitions to media-over-IP networks, “It will be interesting to watch how quickly SMPTE ST 2110 adoption will take hold on a wide basis,” he adds, “and whether new 4K/immersive buildouts will rely on SMPTE ST 2110 infrastructure or stay with SDI.”
Any new equipment will need to support the requirements of immersive audio mixers, says Mark Davies, director of products and technology, TSL Products. “With even more audio to monitor, it is important that we make life as easy as possible for operators, presenting clear and concise displays for them to confirm everything is in the right place and legal at the point of monitoring—and allowing rapid fault-finding when things do go wrong.”
Calrec Audio already offers an immersive audio solution, the ImPulse audio processing and routing engine, reports vice president of sales Dave Letson. Supporting multiple next-gen audio formats, “height and 3D pan controls are provided, and paths of all widths can coexist within a mix and be routed to/from each other with flexible panning and downmixing built in,” he says of ImPulse’s capabilities.
For the moment, broadcasters are keeping it simple, says Letson. “One of the most common ways that broadcasters and content creators want to add an immersive component at the present is in sports productions by adding some P.A. in the height speakers to help convey more of the atmosphere and drama of a game. Over time, immersive productions will become more ambitious, but it is understandable that currently an air of caution is predominant.”
Support of next-generation immersive audio for ATSC 3.0, Dolby Atmos and MPEG-H is at the heart of SSL’s System T console architecture, says Tom Knowles, product manager, broadcast systems, SSL UK. “System T has immersive paths up to 12 channels wide—for 7.1.4—with 3D panning from the console surface, which can be fed to the encoding system of choice. This is equally important at the front end of the process, where System T has native support for AMBEO and other ambisonic mic inputs, with GUI control of mic orientation and focus.”
With object-based immersive audio schemes, metadata handling will be critical, says Schindel, not least for the potential personalization features such as foreign language commentary. “While metadata will be more critical, and critical to get correct, it’s also going to be easier to author and use,” he says.
“Much of the new metadata will come down to identifying what the audio actually is—dialogue, effects, music, M&E bed mix, et cetera—and where it should be placed in the soundfield. Without this information, downstream encoders and decoders will not know what to do with the various audio elements.”
As with any jump from one audio format to the next, “there are other common-sense elements to consider as well,” Schindel says, “such as making sure that the mix sounds good in immersive, in 5.1 and in stereo. There will be viewers listening in all of those formats.”
Knowles agrees. Content is now watched on a wide range of devices, from TVs to handhelds. “The ability to up- or downmix content for different delivery media without additional work is a massive efficiency for operators and gives solid flexibility and futureproofing to broadcasters,” he says of System T.
Exactly when the immersive content pipeline might start flowing is a chicken-and-egg situation, suggests Schindel, noting that some immersive sports programming is already available in the United States and Europe. “Broadcasters often do not want to integrate a new format until there is content to broadcast, and content creators don’t want to produce content in the new format until they know it can be delivered to the viewer. I think in the next 12 to 24 months you will see immersive content broadcast regularly,” says Schindel.
“Broadcasters have committed to launching ATSC 3.0 services in 60 markets across the U.S. during 2020, and this includes the top 40 markets. The pipeline will largely be in place then, and it’s just a matter of the content.”
Owens is less bullish. “I think we may see it in network content—entertainment shows—that local stations air. Metadata for correct panning can be inserted at the network end. For the local affiliates, it should be a pass-through, but I don’t see widespread implementation for another five years or so.”
“You need to look at different content types,” says Davies. “Movies have been produced for some time with immersive audio, and it is relatively easy to transfer this straight to TV. Live TV, especially sports, attracts the biggest audiences and hence has higher budgets. However, the production of immersive audio for live TV is a big challenge. Many leading broadcasters are still experimenting with ways to produce consistent but compelling immersive audio.”
Wheatstone • www.wheatstone.com
Linear Acoustic • www.telosalliance.com/Linear
TSL Products • www.tslproducts.com
Calrec Audio • calrec.com
Solid State Logic • solidstatelogic.com