The HD TV Evolution: Part 6 – Resolution Wars [Archive]

Felix Torres

07-10-2006, 03:00 PM

Okay, up-front: this is not about whether 720 HD broadcasts are better than 1080 transmissions and it’s not about how or when some person or another can see the detail on a 1080 screen. All the sound and fury behind those arguments are just plain meaningless for two simple reasons: One, consumers don’t get to choose the format in which their HD content is produced and broadcast in, the studios do. Two, manufacturers have already decided what kinds of displays they are going to build. And, with apologies to Alex Trebek, like it or not, folks, the answer is 1080. The question is, of course: “What resolution is full HD?” <!> Content Here is a short list: -- Disney (ABC/ESPN) -- FOX These are all the companies currently broadcasting HD formatted for 720 display. Here is a shorter list: -- Everybody/everything else. Which is of course, the list of the HD sources that format and distribute their content at 1080 resolution. Easy to see how content providers see the future, no? And it is no accident that the two studios most active in promoting highly restrictive blue-laser copy protection schemes are the same vendors dragging their feet on HD broadcast resolution, right? Both have highly profitable DVD sales busineses and they would rather you bought their highest resolution product instead of watching it via broadcast. Fortunately, the other studios aren't quite as consumer-hostile. Displays Here is a much longer list: <img src="http://www.digitalmediathoughts.com/media/users/634/Part%206%20-%20list2.gif" /> That is a partial list of the HD displays and projectors featuring native 1080 display resolution, shown at CES 2006 in Las Vegas last January, and that will ship to North America this year: 68-strong. A very, very incomplete list. In other words, the decisions that matter have already been made: HD content will be produced at 1080 resolution and manufacturers are rushing to sell displays that present that content at native resolution. No amount of carping about fringe issues will change the fact that, moving forward, HD content will be defined as 1080 content. (This isn't to say there won't be tons of new 720 displays out there - there will. But the understanding will be that they are "truncated", downscaled-presentation devices. Low-end products. The 21st century equivalent of B&W TVs in the age of color CRTs.) <PAGEBREAK> Marketing Strategy From the manufacturers’ point of view, this makes sense because it allows them to segment and stratify the market the way they like it into: “good”, “better”, and “best”, with a nice price differential between the categories. In addition, for once, the stratification won’t be artificial but real and easy to explain to consumers. “Good” will be 720 displays, “better” will be 1080 displays, and “best” will (initially) be big 1080 displays with advanced color systems. Soon—possibly as soon as '07/'08—“best” will be defined as QUAD-HD (3840x2160—play with the math and see why). This stratification will be mapped differently across technologies, of course. LCD vendors have the advantage that their tech allows for HDTVs ranging from 19” to 56” today, with bigger models to come, so there will be plenty of room in the design (and pricing) space for different vendors to distinguish their products. Rear-projector vendors will likely take a slightly different tack using triple-LCD and low-res DLP chips on 720 displays as their entry-level loss-leaders. This will hopefully draw traffic and sell the idea of rear projection TVs to folks overly-enthused about flat panels and then highlight the limited cost differential between the entry level and the larger, noticeably sharper, LCOS and high-res DLP models. Not quite a bait and switch, but a reliable, proven sales pitch… This is how the HDTV market of '07 and beyond shapes up, folks: LCD and rear-projection vendors are going to position 720 displays as the low-end, in the full understanding that their competitors committed to Plasma displays (Matsu****a, for one) will be at a disadvantage in a playing field defined by resolution. Small, cheap LCDs and large, cheap triple-LCD rear projectors will sell the idea of 720 as low end products and till the soil for the Premium-priced 1080 and Quad-HD products. Technology The way it works out, 1080 resolution is actually dirt cheap to achieve for rear-projection vendors. DLP manufacturers can use wobulation to tile lower-res blocks generated by lower-than-1080 chips if they don’t want to spring for the newest 1080-native chips. A bit of firmware coding and color-wheel tweaking and they’re in business... (metaphorically speaking). The expectation is that DLP manufacturers will have completed the transition to a 1080-dominated lineup by the second half of '06. The LCOS vendors apparently have a bit of 720 fabrication capability to write off, as they only expect to completely move to 1080 by the first-half of '07. The way one LCOS manufacturer rep described it was that, for their tech, two million pixels per chip is no harder than one million. (Have to wonder if INTEL agrees). On the LCD side, the transition does involve new manufacturing facilities but apparently all the major players have already designed their new capacity coming online this year for the higher-resolution panels. So, they're ready for a phased transition from the top down (40”+ panels first, followed by 37” and possibly even 32”-ers) starting the second half of this year. Beyond that, second-tier vendors looking to improve their credibility are already starting to show off QUAD-HD LCD panels for (promised) late '06 early '07 release. QUAD-HD is the next frontier in the resolution wars, but most consumers won’t have to worry about that particular battle until 2009 or so. Just keep it in mind: 1080 isn’t the end of the road for HD video and advanced electronics can extract enough meaningful data from a 1080i stream to productively drive even a QUAD-HD display. Plus, even as we speak, plans are apparently afoot to establish standards for QUAD-HD video. NHK in Japan has done some interesting demonstrations. Check this for a brief intro: <a href="http://www.arnnet.com.au/index.php?id=1909545513">http://www.arnnet.com.au/index.php?id=1909545513</a>. Even PDP vendors are getting into the game, with both Panasonic and Pioneer announcing 50” 1080p product for this summer. LG already has a 65” product and is promising a 75” panel. Neither is likely to be a volume product but at least it shows the flag… The thing to keep in mind is that the move to 1080 is not a technical matter and it is not up for debate; the issue is economic and competitive and the decisions that matter have already been made by the players that matter. Of course, manufacturers and retailers have to clear out the pipeline of the existing premium 720 products. So, anybody who truly prefers 720 displays should be on the look-out for bargains as they close out the existing models and replace them with feature-lean models intended to serve a lower-priced market. You have been warned: you can’t buy what isn’t sold, after all, and moving forward, the feature-rich, mid-range and high-end replacements for today's models will be 1080s, not 720. <PAGEBREAK> The Interlacing Question Now, there is one technical aspect of 1080 displays that does need addressing - interlacing (and de-interlacing). Two aspects of it: First, most folks don’t realize that all fixed-pixel HDTVs are, internally, 1080 displays. Every last one. LCDs, rear-projectors, even ED Plasmas. They have to be in order to properly decode all the 1080 content they receive. The way the process works is that the incoming video signal (whether via cable or over the air) gets decoded into a 1080i data stream that then gets de-interlaced into a 60 frame per second frame buffer. On native 1080 displays, this frame buffer simply gets presented to the viewer with no further processing or scaling, unless the user asks for it (zoom factors, overscan settings, that kind of stuff). On other displays, the frame buffer gets downscaled and mapped to the display’s native resolution, whether WXGA, 720, or even ED. Here's where things get touchy: 1080i data streams provide interlaced video fields in pairs (even scan lines in one, odd scan lines in the other) but the field pairs are not each one half of one 1080p/30 frame. Instead, each one is half of a different 1080p/60 frame so that the data from one field to the other is displaced in time by one 60th of a second. Proper de-interlacing of this content requires motion-adaptive processing of the data so that the true matching field for each field received can be properly calculated to generate a full 1080p/60 data stream for display. To put it another way, each displayed frame should contain one transmitted field and one calculated field. And a lot—repeat, a lot—of pre-2005 HDTVs do not properly calculate the “missing” field data in building the frame buffer data stream. Reports are that something like half of the HD display models tested do not build the internal 1080 frame buffer properly. Instead of calculating the proper complementary field, they just replicate the received field line by line, resulting in an actual frame buffer resolution of 1920 by 540 instead of 1920 by 1080, and then they scale down that mangled data stream to the native resolution. Of course, 720 content—what there is of it—doesn’t get shredded this way, which is why a lot of people properly swear that 720 content looks way better on their sets. It does. Not because 720 content is better but because 1080 content is being improperly processed. Which brings us to the second technical aspect of the 1080 "war" - interlaced data streams versus progressive streams. Lots of sound and fury about the lack of 1080p content, or a given display’s lack of 1080p inputs. Well, yes, it would be great if all 1080 displays accepted 1080p signals. But it’s not all that critical. If you think about the reality of what the data transmission process described above does, it's clear that interlacing in a modern HDTV is just another form of data compression and one that is very, very effective. You get 50% compression for an almost un-measurable loss in image quality. Frankly, anybody who can see the difference between the exact same content on the exact same display transmitted from the exact same source, via the exact same port, at 1080i and 1080p had better be hitting .300 with power in the major leagues. Anybody out there looking to buy a 1080 display today and who isn’t going to run PC productivity applications via that display should not hold back on that account. (There are plenty of good reasons to wait to buy an HDTV until you absolutely positively have to—things like 25% yearly price drops, for one, rapidly improving technology for another. But not that one - 1080 content is 1080 content and it all ends up in a 60fps frame buffer anyway). Simply put: the best way to watch 1080 HD content is a 1080-native display. Just make sure it has good quality electronics and you’ll be covered because if the electronics aren’t up to snuff the rest of it won’t matter one whit. And since the vast majority of all available HD content is and will be 1080-resolution… Enough said. Next up: wrapping it all up with a bow so I can skip town. Felix Torres is a dabbler in home entertainment electronics and a survivor of both the home computing wars of the 80's and the multimedia wars of the 90's who is currently most interested in home media networks and the North American transition away from broadcast media.