HDTV Past, Present and Future - Part 2 Future

In our last article we traced the origins of HDTV and looked at practical considerations for HDTV enthusiasts and system designers. (Part I is available here) In this article we'll take a closer look at the trends and technology that are shaping tomorrow's HDTV systems and examine their impact on today's planning and purchasing decisions.

HDTV Tomorrow

Just as HDTV begins to enter consumer electronics mainstream, it is poised for yet another evolution. The architects of today's HDTV system, long ago, envisioned a day when advancing technology would enable what is now known as "full HD resolution." For HDTV buffs this resolution is known simply as "1080p."

While today's HDTV standards actually embrace a multiplicity of different display standards, the most common HD resolutions are known as 720p (1280 x 720 pixels @ 60 Hz refresh) and 1080i (1920 x 1080 pixels @ 30 Hz refresh). Where the "p" denotes a progressive (a.k.a. non-interlaced) scanning system and the "i" denotes an interlaced scanning system. Without delving too deeply into video theory it is sufficient to say that a progressive scanning system is superior to an interlaced system if the resolutions of both are the same. This is because certain artifacts cause a loss of vertical resolution in interlaced scanning systems, particularly if there is vertical motion (e.g. movie credits that scroll up the screen). There is much debate between video enthusiasts as to which of these two formats is "better" -- 720p because of its inherently stable progressive scanning system or 1080i with its ostensibly higher resolution. While these two formats have fundamental differences, they have one surprising thing in common - they require the exact same amount of bandwidth. This is because both systems use a pixel clock frequency of 74.25 MHz in the analog domain. In the digital domain, DVI and HDMI signals based on these resolutions have a bit rate of 742.5 Mbit/sec. (see Figure 1).

1080p

The debate over 720p vs. 1080i continues, but one thing is clear - a system that offers the best of both would be ideal. In other words, combine the high resolution of the 1080i system with the stable progressive scanning of 720p. The result is 1080p (1920 x 1080 pixels @ 60 Hz refresh). A very important aspect of 1080p is that it requires double the bandwidth of its lesser HD siblings 720p and 1080i. The SMPTE 274M standard defines the pixel frequency for 1080p/60 as 148.5 MHz; the digital bit rate is 1.485 Gbit/sec.

From its earliest days in the primordial cosmos of HD, 1080p has been the "holy grail" of HDTV developers. However, the technology to create and display 1080p images has been astronomically expensive until just recently. There are now a few 1080p displays on the market such as Sharp's PN-455, a breathtaking 45" LCD monitor. More 1080p capable displays are appearing and many more are in development.

Next-Generation DVDs

The real driver for widespread adoption of 1080p hinges not only on the availability of 1080p displays, but the accessibility of usable source material. There are relatively few 1080p sources that are within the grasp of most consumers. One good example is Microsoft's Windows Media High Definition Video. Microsoft allows users to download 1080p video clips from Microsoft's WMV HD Content Showcase and play them back using a current version of Microsoft Windows Media Player (version 9 or higher):

http://www.microsoft.com/windows/windowsmedia/content_provider/film/ContentShowcase.aspx

There are only a small handful of DVD titles available using Microsoft's WMV-HD format, but as long as your PC and monitor are up to snuff, you can watch these 1080p flicks right now. For the rest of us, we'll have to wait for the next-generation DVD players to hit the market. If the consumer electronics manufacturer's have their way, that wait will be measured in months, not years.

Currently, two formats are competing for the next generation of high definition DVD players: the HD-DVD standard, developed by Toshiba and NEC, and Blu-Ray, developed by Sony. Each group has a backing of diverse constituents from the video and PC industries as well as Hollywood studios. So far, each group has not made any compromise that would allow a single, unified standard to emerge. The stakes are incredibly high, as today the home DVD player and recorder market is valued at $10 billion per year. The global value of all DVD non-hardware products is expected to grow at an average 18 percent a year to $77 billion by 2009, up from $33 billion in 2004, based on market research from In-Stat, a high-tech market research firm.

What is clear is that the companies that establish the next DVD standard will reap royalties on their technology for many years to come. It is also clear that these next-generation DVDs will accelerate adoption of full resolution HDTV (1080p) because other forms of delivery (cable, satellite, off-air) will probably take years to catch-up because of the huge amount of spectrum required to broadcast HDTV at 1080p resolution.

Many industry analysts agree that the rapidly accelerating move toward 1080p may eclipse today's HDTV standards. In its February 2005 issue of Projection Monthly , Insight Media, a respected market research firm based in Norwalk, Connecticut had this to say about 1080p's potential:

We believe that 1080p will emerge as the new HD standard for all consumers. This will be driven primarily by consumer preference in not wanting to be "burned" from buying into a technology too soon. No one wants to buy a product that eventually devolves into a "stop-gap" solution with "limited" display resolution. Never mind the present content void, or the fact that very few consumers can discern the difference between the formats - the 1080p display spec will become a check-box line item required to "future proof" their purchases. Imagine plopping down $4K, $6K, or even $8K for the hottest new display only to learn 9 to 12 months later that a 1080p broadcast or Blu-Ray HD DVD movie is "downrezed" to match your lower display resolution.

Future-Ready HDTV

Does this sound great, or just sound confusing? No matter how you look at it, technology marches inexorably onward. The big question is what to do about it? If you recently purchased an analog HDTV system, don't open the window just yet. There's a good chance that your system will be supported, albeit at lower resolutions, for years to come. However, if you are contemplating a new HDTV system, take a moment to consider these important questions:

1. Do I want a system that will display 720p and 1080i only, or do I want a system that will show full HD resolution (1080p) either now or in the future?
2. If my system only does 720p and 1080i, how important is it for me to have an upgrade path to 1080p? What system level infrastructure would be needed to support a future 1080p upgrade?
3. How can I be sure that ALL my system components will work in a 1080p environment?
4. I'm running DVI and/or HDMI cables inside my walls, how can I be sure they will work with 1080p sources when I upgrade my system down the road?
5. How far away can my system components be from my display?
6. Who can help me figure all of this out?

These are just a few of the important questions that the owners of HD systems must consider as 1080p emerges into preeminence as the HD format of choice in the new era of digital television. Fortunately, there are people to help you make this transition.

We would like to thank Steven Barlow of DVIGear for allowing us to reprint this informative article.

About DVIGear
DVIGear has been at the forefront of the digital connectivity revolution since 1999 when the DVI standard was first introduced. DVIGear offers a wide range of digital connectivity solutions in four key areas: high resolution digital cables, adapters, wall plates and electronic distribution and conversion products.

DVIGear operates in three distinct disciplines: digital Education, Solutions and Products. These elements form the core of DVIGear's d-ESP support program. Our belief is by engineering superior products and offering world-class technical support, we can deliver superior solutions that not only take the hassle out of dealing with changes in technology, but actually make it fun. Contact us to learn how we can put our digital expertise to work for you.