1080p: HD luxury or necessity?
If you listen carefully to the belligerent HD format debate pitting 1080i against 720p, you may catch a murmur rising in the background: 1080p.
ESPN’s HD push is based on
progressive-scan, which it says is
better for sports content.
Among the early boosters of the format is high-def programming outlet HDNet. For HDNet, the quality argument of 1080p wins. "1080p is where we think we need to go," says Philip Garvin, HDNet's general manager. "For us, when you come to the HDNet Channel we want you to say, 'Wow, that's the best quality [I] have ever seen'."Getting the picture
That said, Garvin acknowledges there are plenty of steps before cable can bring 1080p to the HDTV screen. That starts with developing video cameras that shoot using 1080p and the associated production gear. 1080p movie cameras are already on the market, and they are producing a noticeable quality improvement, according to Garvin.
"What you are going to start seeing is a greater disparity between programming shot in 1080p as opposed to 35 millimeter. The high-def originated movies are going to start looking better and better in comparison," he says. "Even today, when we show on HDNet Movies a movie shot in HD [and] originated in HD, as opposed to one originated in 35 millimeter, the one in HD is looking better."
On the television production side, equipment makers are starting to come out with 1080p camera designs, and those "will be available next year," Garvin says.
That trend was in evidence at the recent National Association of Broadcasters (NAB) convention, according to Chuck Pagano, ESPN's senior vice president of technology engineering and operations.
"A lot of the vendors were talking about where they are headed with it–some were showing simulations, not necessarily hardware yet. But it is definitely on the dashboard of the equipment manufacturers, especially from the camera side of the equation," Pagano says.The bandwidth problem
Even if such equipment does come to market, probably the biggest issue standing between 1080p and commercial service reality is transport bandwidth. By combining the higher resolution of 1080 with the greater refresh rate of progressive, 1080p is even more data-dense and could soak up even greater bandwidth.
That starts with the video produced from 1080p cameras. At present, 720p and 1080i cameras output video at about 1.5 Gigabits per second, but 1080p would roughly double that to 3 Gbps, Pagano says. To convert that into a standard 19.4 Megabit per second channel for transmission across a cable network, "there's a whole set of other technologies that have got to be accomplished in between there."
While video channel bandwidth does depend on the compression scheme used, 1080p would likely require greater compression or greater bandwidth. That's one reason Starz! Encore Group isn't actively looking at the 1080p format, according to John Beyler, executive vice president of technology operations at Starz!.
"It would take too much bandwidth to do it. 1080i barely fits for some types of content–for example, sports–and concerts and specials," Beyler says. "For some types of content there just are not enough bits with 1080i. 1080p would be even that much more demanding."
Garvin, however, argues that has not yet been proven, especially given advances in MPEG-2 compression. Because of the intricacies of compression algorithms, just because there are more frames to compress doesn't mean the video quality will suffer, he says.
"So the question is, how good of a job can you do going from 1080p to MPEG-2 at 19.4 (Mbps)? And will going from 1080p to 19.4 be better than going from 1080i to 19.4?," Garvin asks. "We know that when we ultimately can record 1080p, the recording will be better. What we don't know yet is whether 1080p looks better compressed at 19.4 than does 1080i. We believe that it will, but we obviously haven't seen that yet."
There is some promise 1080p's bandwidth picture could improve with advanced video codecs, including MPEG-4/H.264 and Microsoft's Windows Media 9, which offer far greater compression rates while maintaining video quality.
Garvin sees possibilities in advanced codecs, "but right now none of our distributors have the ability to handle it," he says. "When we do our tests on MPEG-2, we will certainly see if there is anything else."
And aside from the fact these codecs as yet cannot reach the existing installed base of digital set-top boxes, Beyler also doubts the efficiency they offer would be used to deploy 1080p.
"If you went to MPEG-4 or wavelets or some other algorithms, then you could get much more efficiency. But I don't know that you would use that to go to 1080p or if you would use that to do multiplex screens of 1080i or 720p," Beyler says. "So I don't necessarily see more movement toward higher levels of HD with compression improvements, but for more of the formats we've been delivering."The consumer argument
And finally, 1080p has to pass the business case test with consumer electronics suppliers and cable operators.
ESPN’s Chuck Pagano is
keeping an open mind about 1080p.
LC-45G1U, a 45-inch 1080p liquid crystal display. The Sharp unit is set for debut mid-year, while Samsung expects its 1080p set to roll out toward the end of 2004. Pricing isn't yet fixed for the units, although they are expected to be at the high end of the HD cost spectrum.
For the consumers who already have plunked down money for an HD set, will they see a picture improvement from a 1080p signal if it is coming through a digital TV set that displays in a lesser format? There seems to be some argument.
Beyler points out that many of the HD sets available now render in 720p, and when they display an incoming 1080i signal, the viewer doesn't see all of the original pixels.
"Up to now, the high-def displays have really been medium-definition if you look at them closely. The CRT-based displays, they would give you full resolution. But the flat panel displays–the plasmas, the DLPs– most of that technology is topping out at 1,200 or 1,500 pixels per line horizontal," Beyler notes.
But Garvin doesn't think the format has to wait for consumer television sets able to render video at 1080p. While they may still display in a lower format, the situation is much like viewing a higher-quality DVD next to a more stripped-down VHS tape video on the same set; while the format it delivers the video in is the same, there is a noticeable difference in picture quality because the DVD version has more detailed visual data.
"So even though it is coming down to some lower-level format–be it DVD or VHS–you can tell when it starts out at better quality," he says. "Same deal here. If we start out at a better quality 1080p than 720p or even 1080i, we believe that [in] the home–even though the last piece may be an inferior device–you'll see the difference."
Still, others in the industry doubt 1080p will ever make a splash in HD. Harmonic Inc., a supplier of video encoders, isn't exploring development of 1080p, nor do its encoders support the format "and it is not supported because we do not see really a reason to support it," says Yaron Simler, president of Harmonic's convergent systems division.
Contrary to others, Simler says broadcasters at NAB were not talking much about 1080p. While the technology was present, there was not much interest among broadcasters, he says.
"When asked, they are not interested," Simler notes. "I think people are actually moving to (1080)i and they are really looking more at 720p." Based on discussions with other broadcast technology experts, 1080p "is not anything that you will see any time on the television near you," Simler adds.
Likewise, Comcast Corp. hasn't been convinced that 1080p is the way to go, according to Mark Hess, the MSO's vice president of digital television.
"The format itself doesn't provide enough incremental picture quality to warrant the bandwidth and whatever other cost even the content providers get into," he says. "While there might be some display units out there that support it, I don't think anybody is transmitting in it. We have never made any attempt to try to support it."
Advanced codecs might improve the case for 1080p, but again Hess argues there has to be a substantial jump in quality to really make it worth Comcast's while.
"I think at the end of the day the same thing kind of rules–unless there is some kind of 'whoa' jump-in quality, even divided by two or whatever we can get to with codecs, bandwidth is still a valuable commodity. So you really need to have a jump-in experience before someone is going to start jumping on this bandwagon," he says.
Despite all of the obstacles, Pagano won't rule out the idea of 1080p coming to ESPN. It also doesn't hurt that ESPN chose 720p as the format for its broadcasts.
"We're keeping our eye on it and trying to understand the dynamics associated with it. And that gives me even more credence–that I'm glad I went progressive to begin with," Pagano says. "Because it should be a mathematical exercise to get up to 1080p 60 (frames per second) when we do make that decision."
With high-def video stock already in 720p, "at least I will have some stuff in the can that is already progressive," he says. "It's a lot easier to make progressive to progressive than it is to make interlace up to progressive, because you can't make information out of nothing."
Similarly, Starz Encore also is taking a wait-and-see approach.
"There is always new technology and new compression and distribution, and we are going to keep our eyes open. And if it is something that develops in the marketplace and our subscribers want [it], then of course we'll do it," Beyler says. But as for right now "we're just happy our high-def channel is up and running and getting Starz! and Encore out."
In contrast, HDNet's Garvin leaves little doubt about his confidence in 1080p, saying its adoption is not a matter of if, but when.
"The great thing about 1080p is it puts away all of the conversations about 720p versus 1080i. We can just get all of that behind us and all be originating in the 1080p world," he says. Such unification is "not could be, but will be. 720p will almost certainly give way to 1080p and so will 1080i–ultimately, in the long run."