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Real convergence

The annual NAB conference in Las Vegas is advertised as the world’s largest electronic media show. To accommodate all of the new technologies that have been converging during the past decade to create and distribute electronic media, the NAB expanded the show to include the multimedia world.

While the NAB has been officially promoting convergence, for most of the past decade the multimedia world exibits were segregated from the broadcasting exhibits and inconveniently located in the Sands Convention Center. Now that the Las Vegas Convention Center (LVCC) has expanded, the multimedia world exhibits have gradually been integrated into the NAB mainstream.

This past April, as I walked into the lower level of the LVCC South Hall — the hall that the NAB calls multimedia exhibits — I could not help but feel that the much-ballyhooed convergence was finally happening. Apple and Avid dominated the entrance to the lower level of the south hall, much as they have come to dominate the new landscape of digital media. Farther into the hall you could find Adobe and Discreet Logic. Together, these companies now command the markets for tools used to create TV, video and film. Thanks to convergence, the concept of digital motion imaging is being devoured just as the world of digital audio was a decade ago.

Figure 1. There are three important areas of technology that are facilitating the real convergence that is transforming the landscape of digital media. Perhaps the most important is high-resolution display technology. The most powerful force is cheap IT-based digital processing components. The most elusive is high-resolution image acquisition. Click here to see an enlarged diagram.

The myth of convergence
The classic myth of convergence is that the worlds of television and personal computing would become one, and that everyone would surf the Web on their TVs or watch TV on their PCs.

But the TV has traditionally been a device viewed passively at a distance. This has become known as the lean-back viewing experience. TVs, especially the big screens in the family room, are often viewed by groups of people. Interactivity has been limited to the remote control; efforts to make the TV viewing experience more interactive have largely been met with disapointment. This may change, but the big-screen TV in the family room will likely continue to be used primarily for the lean-back viewing experience.

The PC has traditionally been a device used up-close and interactively, by individuals. This has become known as the lean-forward viewing experience. Studies suggest that millions of people multitask and use their PCs while watching TV. Many people have equipped their PCs with TV tuners, but it is both easier and cheaper in most cases to put a TV in the same room with the PC. As the average screen size of a PC increases, however, it is becoming more practical to use this relatively expensive digital-media appliance as a PC, TV and stereo.

The classic definition of convergence misses an important point. With a myriad of choices in cheap consumer-electronics gear, consumers have become accustomed to buying purpose-built devices. People are more interested in having these devices share their media content, and consumers tend to choose appliances that are appropriate for the venues in which they will use them.

The reality of convergence
The unreality of convergence for the past decade has been due more to political concerns than technical limitations. We are experiencing a classic technology shift, and it is shaking the foundations of several media industries. These industries are converging around a new reality: Virtually all forms of media can be represented as bits. In the legacy analog world, media and the appliances people used to consume them were tightly coupled. In the new digital world, media are files, and the ability to use these files is more dependent on software than the underlying hardware that executes the programs and algorithms. Over the past two decades, there has been a relentless progression as all things digital consume one medium after another. The typewriter gave way to the word processor and the artist’s paste-up board gave way to desktop publishing. Audio was consumed next, and SD video was swallowed up by the end of the last decade. Now it is HD video’s turn. This progression will soon take over the world of film as well.

The reality of convergence has more to do with the underlying technologies for creating, distributing and viewing all forms of digital media content than the classic definition implies. Figure 1 shows that the applications are not converging. Instead, the technologies that support these applications are converging.

The venerable CRT display is finally reaching its end of life. In the past year, major manufacturers of CRT displays have announced that they are shifting investment to next-generation display technologies, including LCD and plasma panels, and LCD, DLP and LCOS projection systems. All of these displays have individually addressable pixels that create image rasters nearly free of the geometric distortions common with scanning CRT displays. All of these displays have the ability to present both Nyquist-filtered imagery (video, film and digital photos) and the unfiltered imagery common to many computing applications, including the ubiquitous Web browser.

This past December, these new display technologies began to outsell CRT-based direct-view and projection sets in the rapidly growing home theater/HDTV product segment. While cheap, CRT-based TVs still dominate the market, the era of the CRT is clearly drawing to a close. With it, one of the last barriers to real convergence is crumbling. The increasing speed and/or storage capacity of cheap components used in the IT-industry continues to devour applications that place heavy demands on digital media, including high-resolution motion imaging. Compression-based desktop video systems soon gave way to uncompressed video systems. And, as HD production became a priority, cheap IT technology became a solution.

Figure 2. The progression in storage capacity for Panasonic’s P2 storage cards is symbolic of the trends in CPU performance and hard-disk storage that are making the shift to HD affordable for everyone. Click here to see an enlarged diagram.

A prime example of how this avalanche of bit-processing power is impacting the future of digital media production can be found in the Panasonic P2 product line introduced at NAB2003. Based on Panasonic’s SD memory-card technology, P2 camcorders will capture images directly to memory cards or to cheap hard disks using an IEEE 1394 cable. The first SD P2 camcorder is now shipping, and Panasonic showed a mock-up of an HD P2 camcorder at NAB this year. Figure 2 shows how these P2 products will be able to leverage the geometric progression in storage capacity over their useful life.

The ability to acquire high-resolution imagery continues to be the most elusive barrier to convergence. This is largely due to the fact that the core technologies are not being driven by the same geometric progression that is influencing all things digital. Cameras are, by nature, analog; they capture photons, not bits. The CCD sensors used in virtually all HD cameras today are analog devices devices that are nearing their practical limits in terms of resolution versus SNR performance. There are signs that the HD acquisition problem may be yielding to other technical innovations. Perhaps the most promising is a new generation of high-resolution CMOS image sensors that overcome some of the limitations of CCDs. These sensors take advantage of many of the chip-level manufacturing techniques that drive the relentless progression in CPU- and memory-chip performance.

HD for everyone
Apple has been riding the IT-performance curve through its support for the compression codecs used in Panasonic’s DVCPRO products. DV-25 and DV-50 software codecs were introduced over the past two years. At this year’s NAB, the companies introduced the DVCPRO HD codec (100Mb/s), which can support Panasonic’s 1080i and 720p Varicam products.

At the Panasonic press conference, vice president of marketing Stewart English plugged an Apple Powerbook into a Panasonic DLP projector and played a three-minute infomercial at full 720p resolution. HD has been devoured. Soon, digital media professionals will look upon the soft, fuzzy images of interlaced SD video just as people looked at those jerky, postage-stamp QuickTime movies a decade ago. HD is about to become the new currency of motion imaging.

Craig Birkmaier is a technology consultant at Pcube Labs, and he hosts and moderates the OpenDTV Forum.