Step-by-Step To High-Def
Cable networks conquer production challenges to launch HD channels
By Glen Dickson -- Broadcasting & Cable, 2/26/2006 7:00:00 PM
Premium movie networks like HBO and Starz had plenty of HD-ready film content to draw from when they launched HD services years ago.
But basic-cable HD players like MTV's new MHD, National Geographic's new NGC HD network and Scripps Networks' upcoming HD versions of HGTV and Food Network have had to significantly change their production workflows to ensure a reliable stream of HD content.
Nat Geo's Year of Planning
NGC HD went live in January, after almost a year of planning. The HD network offers a simulcast of the programming on the standard National Geographic network in the 720-line progressive-scan format preferred by Fox for its HD offerings; Fox Cable Networks is a part owner of Nat Geo, and the HD channel is uplinked from Fox facilities in Los Angeles.
“Everything basically comes out of our server uplink that's HD,” says John Ford, Nat Geo executive VP of programming, “and that either goes directly to the HD channel or we do a 'pulldown' for 4:3 [aspect ratio] to run on the standard-definition network.”
But National Geographic doesn't air much content in the 4:3 aspect ratio on its standard-def channel. Instead, it shows many programs letterboxed, and it did so even before its HD launch. Ford asks producers to frame a “safe area” for 4:3 on some shows, to give Nat Geo the option of filling the screen on the standard-def channel.
A year ago, Nat Geo told program producers that they would have to begin providing new material in HD. Previously, most producers used 16mm film or Digital Betacam tape, not 35mm film or HD video.
“We found their budgets went up somewhat but not astronomically, and our producers responded well,” Ford says. “It's a benefit for them, too. It gives more value to their archive and gives material a long-term shelf life.”
Most Nat Geo independent producers rent HD cameras, although National Geographic will also lend out its five Panasonic Varicams. The network prefers HD content in either the Panasonic D-5 or Sony HDCAM SR (Super Resolution) format and has built its operations around HDCAM SR. NGC tries to avoid accepting tape masters in the basic HDCAM format because of its compression rate: The video-data rate of HDCAM is 140 megabits per second (Mbps) compared with 440 Mbps for HDCAM SR. The SR version also records more audio tracks to support Dolby Digital 5.1 sound.
Ford also doesn't want producers to work in the low-cost compressed HDV format, which has a data rate of 25 Mbps. The quality isn't sufficient. But he makes exceptions: “If you are going to hang over the side of a mountain and shoot a snake crawling up into a bird's nest, you probably don't want to do that with a $150,000 camera.”
About 90% of National Geographic's prime time fare is now in HD, and the network is adding 30-35 hours of HD programming each month.
Sometimes, Nat Geo documentaries have to incorporate standard-definition archived footage, which the network improves by running it through a color-correction system and a Teranex upconverter.
“We try to make it look as good as possible, but we're acknowledging it's not HD,” says Ford. “It's like using black-and-white films from the '20s. Viewers expect certain things not to be HD. They know they didn't have HD cameras on D-Day.”
MHD: The Network in a Truck
MTV Networks introduced its high-def channel, MHD, in January. It's delivered in the 1080-line interlace HD format and draws content from MTV and sister channels VH1 and CMT.
MHD is all about live concerts and awards shows. And in reality, that's the best way to bring high-def to music fans. While many music videos are shot on film, only a handful have been produced in HD. MHD is talking with record labels to start filling that void.
MTV created an MHD studio on top of Vail Mountain in Colorado, but that facility is used only to capture short interstitial segments in high-def, such as MTV “veejays” introducing a concert telecast.
Supporting MHD's early high-definition production is Pegasus HD, a new 54-foot mobile HD production truck used to produce a series of live Music With Altitude concert specials in Breckenridge, Colo., last month. The oversize truck will be kept rolling to produce major events, such as the MTV Music Awards, and live music shows, such as CMT's Crossroads.
“It's brand new and built by us to our specifications,” says Steve Kaufman, senior VP, production operations and technology, MTV Networks. “It's an entertainment-specific production truck for major events to shoot high-def.”
Because it has such a specific use, Pegasus HD has a host of digital audio gear for producing concerts in full Dolby Digital 5.1-channel sound, including a Calrec digital audio console and an array of Dolby surround-sound encoders, monitors and decoders.
Kaufman contends that producing live music events in Dolby Digital sound is more challenging than sports audio. Part of the challenge is technical; the rest, creative.
“It's difficult to do a live surround-sound 5.1-channel mix,” he says. “Usually, we do a reference mix for an event, a 48-track recording, and remix it later to surround sound. Switching from band-to-band music mixing in surround is a bit more delicate. Surround-sound music is historically two-channel front, left and right. And psycho-acoustically, when you're watching a performance in front of you, you don't expect [to hear] music behind you, like a movie, where you might expect noise behind you when a train or plane goes by.
“There has got to be some sort of psychological basis for putting it behind the viewer,” Kaufman continues, “and we're still playing with what goes behind you in the performance. You have to delicately listen to that in the production truck, and it's hard to get a delicate mix done [live].”
To keep the quality as high as possible, MHD uses Dolby E compression technology only to deliver satellite feeds back to its Long Island, N.Y., tech center. It does not use Dolby E to record audio on tape or server, instead recording six discrete audio channels.
In part, that is why MHD adopted the Sony HDCAM SR tape format, which has 12 audio channels in addition to MPEG-4 advanced video-encoding technology.
Other Pegasus HD gear: Ikegami cameras with Fujinon HD lenses, a Sony MVS-8000 video switcher, Chyron graphics systems, EVS disk recorders and Utah Scientific routers. Most editing is done in New York on a mix of Avid Media Composer and Apple Final Cut systems.
MHD records most camera feeds to Sony HDCAM SR tape decks. Kaufman says that's because the network experiences a “format-compatibility problem” with different manufacturers' servers.
“That is one of the hazards in the digital world,” he says. “When you make a Betacam tape, you can carry it anywhere and play it. In the digital world, it's a much different bag. There are no assumptions you can make about the compatibility of media; you have to call ahead and see what to bring with you.”
Scripps set to launch two networks
Scripps Networks is playing a doubleheader. It will launch HGTV HD in late March and Food Network HD in the second quarter. Executive VP of Operations Mark Hale began preparing for the shift to 1080-line interlace HD early last year, getting gear in place at the network's Knoxville, Tenn., headquarters and in New York.
He replaced several aging post-production systems in Knoxville with new HD-capable systems, including Avid Symphony Nitris and Adrenaline editing systems and Discreet Flame graphics. Scripps also began augmenting Food Network's newer New York production facility with HD gear. Hale estimates that a third of Scripps' post-production systems are already HD-capable.
Scripps used Sony Digital Betacam as its house tape format but is shifting to HDCAM tape, which is backwards-compatible with Digital Betacam.
In Knoxville, Scripps up-­ graded field cameras to Sony Cine­Alta F900 models. In New York, HD video-processing cards were added to Thomson 5000 studio cameras.
“From a legacy standpoint, we want a format that can move content back and forth,” says Hale about Scripps' decision to go with HDCAM.
Other HD gear at Knoxville: Thomson Grass Valley Trinix HD signal router and the Octimax 5.1 audio processor by Linear Acoustic for 5.1 surround-sound simulation. Scripps is also testing an Omneon HD server for playing out programming.
Scripps hasn'tripped out Knoxville's existing routing infrastructure, already standard-def digital, but it has overlaid high-def capability where necessary.
Because 90% of HGTV's programming is produced by outside companies, Scripps needed their cooperation. It mandated that all its programs be delivered in two versions: one on HDCAM tape, the other in a standard-definition version on Digital Betacam.
So far, Scripps has amassed a library of 750 hours of HD material and plans to broadcast 1080i HD at a data rate of 15 Mbps. It will use a Teranex format converter to upconvert standard-def interstitials and commercials to maintain a consistent look.
Teranex technology, Hale says, “takes the center 50% of screen and leaves it untouched and takes the outer 25% [at each side of] the screen and gently stretches it to fill the 16:9 raster [display area]. So you don't get pillar-boxing going in and out of breaks.”
HGTV HD won't simulcast the standard-definition service but will instead offer distinct content, including different episodes of the same show in a given time slot. The new network will also draw high-def content from sister networks DIY and Fine Living.
The programming strategy for Food Network HD, where the bulk of production is field- and studio-based, is being fine-tuned, says Hale, but likely will be similar to HGTV's. He says, “We have an interesting year ahead of us as we see where the audience migrates.”
Next week: Tech pioneers in local HDTV news
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