How ABC.com Plans to Deliver HD Online
Compressed HD Video Will Not Equal Quality on Cable, DBS
By Todd Spangler -- Multichannel News, 5/31/2007 11:00:00 AM
The “high-definition” TV shows ABC.complans to debut in early July will be extremely compressed versions that -- while saving on bandwidth -- will not be comparable to the HDTV services cable or satellite providers currently offer.
The HD video on the broadcaster’s Web site would technically meet a basic definition of HDTV: It will be delivered at a screen size of 1280 by 720 pixels at 24 frames per second.
But the video will be encoded at bit rates far below the MPEG-based HD streams from cable operators, and compression has a bearing on the visual quality of the picture.
Skarpi Hedinsson, vice president of technology for the Disney-ABC Television Group, said his group has tested HD-resolution video compressed at between 850 kilobits per second and 2 megabits per second. “We’re not talking 5 megabits per second or something crazy like that,” he added.
Cable providers typically encode HD streams at roughly 12-19 mbps using the MPEG-2 format, but even the more-efficient MPEG-4 standard requires at least 5 mbps for HD video displayed on large-screen TV sets.
ABC.com uses a video codec from On2 Technologies, a small New York video-software developer, and Hedinsson said the latest versions of its codecs provide better quality at lower bit rates. “We have invested in a facility that has very sophisticated encoding,” he added. “Three or four months ago, I would have said we wouldn’t have been able to do this.”
The site already provides standard-definition video encoded at 1.5 mbps, Hedinsson said, so the step up to 2 mbps seemed feasible: “For us, the delta between HD and SD is not really that great.”
And because ABC.com’s videos are delivered as files, not as live, streaming bits, the service is not susceptible to fluctuations in a user’s bandwidth. Hedinsson noted that the site will include an automatic bandwidth indicator that shows when someone’s broadband connection is sufficient to deliver HD content.
Still, Hedinsson acknowledged that ABC’s online HD -- for now -- won’t measure up to what viewers are used to getting on their TVs. “Does it look as good as over-the-air or cable [HD]? Well, no, there’s more compression,” he said.
The more highly compressed a video signal is, especially with high-motion content like sports, the more likely it is to exhibit visual aberrations like pixelation or “macroblocking,” in which portions of the screen are spattered with multicolored tiles.
Another caveat: A user’s PC must have sufficient processing capability to be able to decompress the HD video.
“It’s not going to be bandwidth that is the problem -- it’s going to be the horsepower on the PC end,” Hedinsson said. “You do need quite a bit of CPU [central-processing-unit] power to render 24 frames per second. We are going to do our best to educate users on what their experience will be like.”
ABC.com’s HD channel, such as it is, will first feature a limited amount of content from its most popular primetime series, including Lost, Desperate Housewives, Grey's Anatomy and Ugly Betty. When ABC launches its new season in September, the site will expand the HD lineup.
The debate over HD picture quality doesn’t belong only to videophile nerds: It’s central to a raging battle between DirecTV and the country’s two largest MSOs.
Earlier this year, at Time Warner Cable’s request, DirecTV was ordered by a federal judge to stop claiming in advertising that its HDTV quality was better than that of cable operators. The judge did allow the direct-broadcast satellite operator to continue claiming that it will soon have three times the HD capacity of cable; the case is pending.
Then DirecTV earlier this month fired off a lawsuit against Comcast, asserting that the MSO’s ads citing a survey in which Comcast’s HD picture was preferred to satellite’s were false.
While ABC’s online-HD claims may not provoke similar litigious responses, some observers detected mainly marketing hype.
“It might sound sexy per se to say, ‘We’ve got HD programs online,’” said Bruce Leichtman, president of Leichtman Research Group. “But certainly, the best way to watch HD is on a big-screen TV.”
To Hedinsson, though, the business goal of ABC.com’s HD launch is to keep ratcheting up the quality of video available over the Internet as broadband speeds rise. “We derive revenue from every single online viewer,” he said. “The question is: How do you keep the viewer engaged?”
