According to AP sports writer Alan Robinson, the broadcast industry has been waiting for a “killer app” that will make consumers give up tried-and-true analog technology for the “brave new world of high definition.” Sports may be the opening broadcasters have been looking for. Coverage of live sporting events has become a hallmark of broadcast television: a constant supply of fresh content that holds viewers' interest — between trips to the refrigerator and the bathroom.
The networks are beginning to get into HD sports production, supported by a new generation of HD remote production trucks. For instance, NMT’s HD4 unit has signed on to broadcast ABC’s “Monday Night Football” in HD.
The combination of sports and TV has even created an alternative TV viewing venue, the sports bar, which inspired the DTV Drafthouse at this year's NAB. What better way to promote the benefits of the HDTV viewing experience than on the big screens of your local watering hole?
So why has it taken so long for HD coverage of sporting events to gain the critical mass suggested by ESPN's recent announcement of the launch of ESPN HD? And what does this announcement say about HDTV broadcasting?
Up close and personal
For the most part, the broadcast networks have limited the coverage of sporting events in HD to a handful of big championship events. NBC has virtually ignored HD sports. The network did allow HDNet to provide delayed coverage of the 2002 Winter Olympics in HD, but did not air any HD coverage via its broadcast stations and affiliates. FOX decided that widescreen 480p was good enough, even for the Super Bowl. ABC offered one season of “Monday Night Football” (MNF) in HD, then punted; but MNF will be back in HD on ABC this fall, along with “Sunday Night Football” on ESPN HD. CBS has provided the most extensive coverage of sporting events in HD; however, the network elected to produce SD/HD simulcasts from a single remote production unit. The compromises that SD/HD simulcasting impose reveal much about the network's attitude toward HD. Here's the dilemma.
There are more than 250 million legacy TV sets. These sets typically have screens smaller than 30 inches diagonal, and are limited in resolution by legacy analog compression standards — NTSC, PAL, etc. There are now about 5 million HDTV-capable displays in American homes. Less than 500,000 of these displays are capable of receiving DTV broadcasts: Most get their HD programming from a DBS or cable service.
As noted in recent “Download” columns, the driving force behind the recent increased interest in HD is the perception that it is becoming an economically attractive premium niche market. Those willing to fork out the bucks for an HDTV-capable big screen TV are typically among the most willing to pay for premium cable and DBS programming tiers.
In contrast, broadcasters have little incentive to provide HD sports coverage. The audience is still statistically insignificant, and the increased costs can be considerable, especially if versions optimized for the SD and HD audiences are produced. The situation is exacerbated by the fact that most of the networks have been losing money on their major sports packages.
Because of the legacy of small screen size and resolution inherent with analog television, sports production techniques evolved into the “up close and personal” medium that dominates today. The enhanced resolution and wider screen aspect ratio of HDTV are often cited as major advantages for sports production. But these advantages are really differences that make it quite difficult to extract a standard-definition version of an event from the HD version.
When ABC produced “Monday Night Football” in HD, they understood these differences, and decided that HD is a different medium — a big screen medium — that demands a different approach to sports production. Thus two production crews and associated equipment were employed for each broadcast. ABC will continue to produce separate SD and HD versions next season.
Despite the advantage of producing a feed optimized for HD screens, the MNF producers and directors struggled at first with the new medium. They gradually learned that they could pull the cameras back and sit on wider shots for longer periods; they had to overcome decades of instinct to provide up close and personal coverage.
The simulcast techniques developed by CBS are driven by the need to serve the larger SD audience. Wide shots come from HD cameras, while the close-ups and slow-motion replays come from widescreen SD cameras that are upconverted for the HD feed. Extra care is needed to keep critical action within the 4:3 “safe area.” The HD audience sees more of the action thanks to the wide screen, and they get the benefit of HD on the wide shots. But the full HD experience is compromised, and image quality varies considerably during a broadcast.
I versus P
To make matters worse, there is another dilemma for the companies that provide the remote production facilities to the networks that produce HD sports. The ATSC standard provides a Chinese menu of format options. FOX uses widescreen 480@60p; CBS and NBC use interlaced 1920×1080@30i; ABC and ESPN prefer progressive scan 1280×720@60p. The cost of an HD-capable remote production vehicle is typically about double that of an SD production vehicle with equivalent capabilities. The latest generation of HD trucks cost between $7 million and $10 million, and typically have a minimum of 16 HD cameras.
From an image processing perspective, it is relatively easy to build production gear — including video mixers, DVEs and graphics systems — that can operate using either 1080@30i or 720@60p.
Cameras are another issue. Most vendors have focused on 1080@24p or 720@24p for the digital cinematography market, and 1080@30i or 720@60p for the live events markets. This changed at NAB 2002, with the introduction of the Thomson Grass Valley LDK 6000 MK II Worldcam. This camera uses an oversampling sensor that allows it to provide outputs for both 1080@30i and 720@60p, which is useful in the remote production vehicle market. To support the growing markets for HD sports production, National Mobile Television (NMT), NEP and New Century Productions have built a new generation of multiformat remote production vehicles with complements of Thomson Grass Valley Worldcams.
Panasonic has enjoyed considerable success in HD sports production with the AK-HC900 HD point-of-view camera. This 720@60p “box” camera weighs in at 3.9 pounds, lending it to use for a variety of unmanned camera positions and for use on lightweight booms and movable camera rigging.
It is likely that the debate over the advantages of interlace vs. progressive formats for sports production will grow in volume in the coming year as “the rubber hits the road.” The progressive proponents note the dramatic improvement in slow-motion playbacks. Many HD sports productions have used SD super-slo-mo systems that are upconverted to HD resolution.
And then there's the question of digital compression efficiency. High-action sports can produce some of the most demanding scenes that an MPEG-2 encoder will ever encounter. Panning cameras and athletes running in and out of the shot — often in different directions — can stress the motion-compensated prediction algorithms in MPEG-2. Many sporting venues have crowds that are close to the action; basketball and tennis may have a large portion of the background in wider shots filled with hundreds of faces that are in reasonably sharp focus. Lighting issues may affect SNR, especially when panning across dimly lit stands; and still photography flashes can create dramatic momentary changes in video levels. All of these issues can add up to produce severe compression artifacts, or the need for resolution-limiting pre-filtering to prevent them.
It is generally held that 720p compresses more efficiently; however, the delivered quality may vary based on downstream interformat conversions. During the recent NBA finals there were reports of widely varying image quality in different TV markets. ABC delivered a contribution quality feed to affiliates, which have different house formats and encoders — interformat conversions and variations in encoder implementations and/or setup may have been responsible for the observed differences.
The stage is set
In the coming year, hundreds of sporting events will be covered in HD. It appears that the majority will be optimized for the HD audience. So the stage is set to answer some competitive questions. There is little doubt that HD sports coverage is going to help the consumer electronics industry sell more HD-capable TVs. Likewise, HD sports will be the cornerstone of strategies being developed by the cable and DBS industries to contend for premium subscribers.
Will HD sports be the “killer app” that will kick the broadcast DTV transition into high gear? Or will it be the technology that causes sports to migrate from “Free TV” to subscriptions services?
Craig Birkmaier is a technology consultant at Pcube Labs, and hosts and moderates the OpenDTV Forum.
NEP Supershooter 20HD production vehicle guardian.nepinc.com/packages/ss20/index.php
National Mobile Television HD production vehicles www.nmtv.com/facilities/fac_trucks.asp
New Century Productions NCP 5 HD production vehicle www.ncpvideo.com/truck-frameset.html
Thomson Grass Valley LDK 6000 MK II HD Worldcam www.thomsongrassvalley.com/products/cameras/ldk6000_worldcam/
Panasonic AK-HC900 HD POV camera www.panasonic.com/PBDS/subcat/Products/cams_ccorders/f_ak-hc900.html
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