Starting this fall, NBC’s Today is being broadcast in high definition with Dolby® Digital 5.1 audio. The popular and long-standing morning show made its latest pioneering move when it premiered in HD on September 13. While many programs on NBC are now being delivered and broadcast in HD with surround sound, Today presents special opportunities for the use of surround sound as it is a live presentation from multiple locations with regular musical performances.

We spoke with Jim Starzynski, Principal Engineer for NBC Universal Advanced Technology, about how the network prepares its surround sound for broadcast. Starzynski is responsible for establishing NBC's audio strategy for DTV and works with leading manufacturers to develop next-generation audio and video systems.

Switching to Surround
According to Starzynski, “When we made the switch to HD, there was no question that all the audio accompanying those spectacular 1080i pictures would be in 5.1-channel surround sound on a daily basis. For Today, we spoke about the exciting possibilities for the concert series at Rockefeller Plaza, and from inside Studio 1A [the show’s main location at 10 Rockefeller Plaza, situated across the street from NBC headquarters at 30 Rockefeller Plaza].”

When preparing the mix, dialogue is steered to the Center channel with a slight spread across the Left and Right channels. Ambience from Rockefeller Plaza is captured with multiple microphones and sent to the surround channels. In addition, original stereo background-music playback along with stereo packages sent to Studio 1A from the 2K pre-control room are processed to create a 5.1-channel mix in 1A control. Engineers use bass management to send low-frequency content to the LFE channel.

NBC built a separate music control room that is dedicated to producing concert audio. Mix engineers can use the LFE here as well to enhance low-frequency content during the musical performances.

The HD audio infrastructure at 10 and 30 Rockefeller Plaza is centered around an HD-SDI system capable of routing 16 channels of 24-bit/48 kHz PCM audio. “Gear connected to the I/O of this routing system determines the placement and the amount of channels used for any signal,” remarked Starzynski. “We use the SMPTE standard for audio channel placement, and a forthcoming SMPTE standard for the insertion of audio metadata into the vertical ancillary [VANC] space of these SMPTE 292 signals.

“In addition, we specified new features for our audio monitoring panels that can mix down 5.1 to an Lt/Rt signal, as well as read and display channel, dialogue normalization, and dynamic range control metadata from the VANC. We also deploy a Dolby LM100 Broadcast Loudness Meter in each HD control room in direct line of sight of the mixing engineer to establish and maintain proper perceptual loudness of each show’s dialogue.”

Metadata Support
Starzynski and his staff also researched the best way to maximize the use of metadata in the audio streams. “The audio metadata component may be the most critical, and most misunderstood, element of a DTV broadcast,” he said. “Because of our familiarity with earlier 5.1 shows, we were prepared to set up metadata for Today. We encouraged our engineers to mix and measure dialogue with a Dolby LM100 at a network standard –23 dBFS, which is compatible with the metadata for our encoders. We went over the benefits of dynamic range profiles, and discussed the differences between how 5.1- and two-channel market stations transmit audio and data to each of our viewer’s home receivers. We listened to and critiqued sample 5.1- and two-channel HD shows that used metadata both properly and improperly to hear and understand the results, good and bad.”

Loudness Levels Across NBC Programming
In addition to Today, NBC has taken various steps to help maintain program loudness for all of its network programming. The network currently uses fixed dialogue normalization and requires each DTV show to match a predetermined loudness level. “Once we test and approve some pending equipment that can sense and pass existing upstream metadata, or generate local metadata when needed, our goal is to distribute all metadata dynamically to our DTV stations,” said Starzynski. (Currently, there are approximately 180 NBC DTV stations; of those, roughly 80 have 5.1 capability.)

NBC also clearly states to all content providers that dialogue level must be measured for Leq(A) with a Dolby LM100 or similar device at –23 dBFS, and dialogue normalization metadata must match the actual audio for transmission as expressed by the ATSC in document A/53D. This applies to all content, including commercials, promotional spots, and programs. (In fact, since the Torino Games in February, NBC has received substantially more HD commercials scheduled for all dayparts, and a growing percentage of this content is provided with 5.1 audio.) Currently, the practice of standardizing metadata permits NBC to pass audio and data consistent with their provider’s content, based on their creative choices.

“NBC is also preparing to roll out a DTV station guide to help all of our DTV O&Os [stations owned and operated by NBC] manage loudness using metadata,” said Starzynski. “We encourage our affiliates and others to employ similar practices as well. All that’s necessary is to take Leq(A) readings across all local dayparts with a Dolby LM100 or similar device, come up with an average for local content, and match the local DTV audio station’s dialogue normalization to that average. It’s simple, very effective, and it completely eliminates outdated techniques and the artifacts associated with loudness processing from the old analog system.”

And NBC’s audience has taken notice. Said Starzynski, “Once Today went HD and 5.1, we heard from our early-morning audience. Like many of our prime-time viewers, the early-morning crowd is excited to receive the crystal-clear pictures and sound that already delighted our evening HD audience.”

To find out more about the Today show broadcasts, visit www.today.msnbc.com
Read more about NBCU and Loudness Management for DTV.
For more information on broadcast loudness and the Dolby LM100 Broadcast Loudness Meter, click here.
And find information on Dolby’s innovative solutions and tools for DTV and HDTV broadcasts here.

BSkyB Captures Soccer in 5.1

The English FA Premier League is one of the most popular soccer leagues in the world, whose games are watched by more than 450 million television viewers in 195 countries. With its exclusive UK broadcast rights for Premier League matches, UK satellite broadcaster BSkyB decided in 2005 to begin producing up to four games per weekend in HD and Dolby® Digital 5.1 surround sound. To maintain the high standards already in place for its SD and stereo service, Sky faced a number of challenges going to HD and 5.1. First, engineers needed to capture enough audio within the stadium for mixers to create an involving 5.1 mix. They also had to develop a robust contribution system using Dolby E technology, and design the entire system to be as easy to rig up and dismantle as possible.

The system Sky devised first captures surround sound using a SoundField system. This device produces four feeds covering width, depth, and height, while providing a fixed center point that helps mixers avoid phase issues when the resulting 5.1 mix is collapsed to stereo. The SoundField mic array’s four feeds are delivered to a dedicated matrix decoder that provides the L, C, R, Ls, Rs, and LFE channels, which are then input to a Calrec mixing console installed in the OB truck. The microphone array itself is mounted below the stadium’s roof (on the same side of the stadium as the primary camera position), and aligned horizontally with the center line of the pitch (the playing field) to provide the most natural image.

The SoundField provides Sky mixers with a baseline 5.1 signal, but they also use additional microphones closer in to the action for specific sounds such as ball kicks and tackles. Multiple Sennheiser 416 directional shotgun mikes surround the pitch. Though this increases the complexity of the mix, it ensures that all on-pitch audio action is captured, allowing mixers to provide the best experience possible to viewers at home.

To help capture the sound of the crowd and stadium ambience, omnidirectional microphones are hung above each end of the stadium. Rival fans usually occupy opposite ends of a soccer stadium, so the omnis help mixers capture all the cheers, boos, and taunts that fans throw at each other.

While testing the 5.1 system, Sky recorded a single match, complete with all the audio feeds, and built a mix in postproduction. The result provided a baseline for subsequent mixing. As the mixers have since become more experienced, more individualized settings have evolved to suit different sites. Also derived during the testing phase were predetermined Dolby E metadata settings. (It is difficult for mixers to set metadata properly in real time, considering soccer’s fast-paced broadcast environment.) Because no metadata is passed on from decoder to encoder during the production and contribution phase of the outside broadcast, no problems will arise should the metadata settings get changed.

Sky mixers steer the on-site or studio presenters slightly apart, on either side of the Center channel. This is done to smooth out the transitions for the stereo taped packages that are sold to other broadcasters. Commentary is steered to the Center channel. (Crowd ambience is also mixed to the Center Channel to further enhance the mix and to help mask the commentators when they need to divert their microphones away from on-air use while talking to the director.) The sound of ball kicks and tackles (picked up by the shotgun microphones) is mixed to the Left and Right channels.

To make the most of the crowd ambience at all times—whether it is quiet and there is very little happening, or when a goal is scored, and the crowd begins to cheer and clap—compression of varying degrees is applied to the constituent parts of the mix. This not only helps to continuously convey the aural excitement and envelop the viewer in stadium sound, but it also allow mixers to maintain focus on the close ball kick sound, which forms a major part of the Sky sound.

The result of all this careful planning is a quick and simple microphone setup (most of the cabling is permanently installed to help with rigging), a console that is already fully configured for the audio inputs and outputs, and Dolby E encoders that are preinstalled with appropriate metadata to ensure quality playback at home. All of this helps Sky produce four matches every weekend in HD and 5.1 with minimal setup and guaranteed audio quality.

See A Guide to for HDTV in Europe for more information about the production, distribution, and transmission of 5.1-channel surround for HDTV broadcasts.

Sound Bytes

Minnetonka Audio Software has released Pro Tools HD RTAS plug-in versions of its award-winning SurCode™ for Dolby® Pro Logic® II for both Mac and PC. The new real-time encoder/decoder plug-in was unveiled at Minnetonka’s booth during the 121st AES Convention in San Francisco after receiving Dolby certification.

Dolby Pro Logic II provides a surround sound experience on any stereo-only television broadcast, turning ordinary television into a total entertainment experience. With over 49 million decoders already in use, Dolby Pro Logic II is the de facto standard for matrix surround in television.

For more information on SurCode for Dolby Pro Logic II, click here.

The 40th Annual CMA Awards were broadcast in Dolby Digital 5.1 surround sound. The three-hour event was broadcast live by ABC on their HD service on November 6 from the Gaylord Entertainment Center in Nashville. This is the first time the CMA has been broadcast in 5.1.

See our press release on Country Music’s Biggest Night™.

The Dolby DP600 Program Optimizer won three awards at IBC2006. These include Broadcast Engineering’s Pick Hit award, the What Caught My Eye award (September 12 issue of IBC Daily), and TVBEurope’s Best of IBC Editors' award. The product will be available in the first quarter of 2007.

The DP600 is our innovative new system for automatic file-based loudness analysis and correction, as well as optional file-based audio encoding and decoding of Dolby technologies for cable, satellite, IPTV, and terrestrial broadcasters.

View our DP600 preliminary spec sheet to learn more about this new product.

The entire Dolby Media Producer suite of products is now available. The Dolby Media Producer suite provides a powerful and convenient software solution for mastering audio files for DVD-Video, DVD-Audio, HD DVD, and Blu-ray Disc media, and the encoder utilizes a client-server model to improve the work flow of postproduction facilities. Contact your local Dolby distributor for demonstration opportunities.

See our DVD authoring/mastering webpage for more information.

Virtually all US prime-time scripted shows are broadcast in Dolby Digital 5.1 on HD services. This includes popular new shows such as:

Brothers and Sisters (ABC)
Heroes (NBC)
In Justice (ABC)
Shark (CBS)
Studio 60 on the Sunset Strip (NBC)
Ugly Betty (ABC)

For a list of digital television shows presented in Dolby Digital 5.1, click here.