Philips Research and Mitsubishi Kagaku Media/Verbatim demonstrated a technology that nearly doubles data storage capacity on DVD+R recordable discs from 4.7GB to 8.5GB. The best feature, according to sources, is that the format is compatible with existing DVD-Video players and DVD-ROM drives. On the consumer side, the benefits are obvious—up to four hours of video on a single disc, while PC users will be able to archive nearly double the amount of data that they can on currently available recordable media.
The dual-layer DVD+R format book, published by the DVD+RW Alliance is expected to be ready before the end of 2003. Recorders for both the PC and consumer electronics markets are expected to become available sometime in 2004.
DVD+RW Alliance member MKM/Verbatim will be one of the first companies to manufacture dual-layer DVD+R media. Tim Clatterbuck, optical marketing manager for Verbatim, says, "We assume that other companies in the +RW Alliance also will make media." Verbatim's target launch date is spring 2004, though the company has not yet determined initial quantities. Upon its introduction, Verbatim's dual-layer media will be more than twice the cost of single-layer DVD+R, says Clatterbuck.
The DVD+RW Alliance has programs for independent software vendors to support dual-layer recording, according to Clatterbuck. Sonic Solutions' AuthorScript engine is already capable of writing "DVD-9" disc images to digital linear tape, as an intermediary step in the replicated DVD production process. Professional authors using high-end Sonic products like Scenarist, Creator, and Producer can take advantage of this capability.
But the potential extends well beyond those upper-level applications. "Even our simplest application is built on the same authoring engine as our top-end tools," says Jim Taylor, general manger of Sonic's advanced technology group. Sonic is working with the companies developing dual-layer recorders to ensure that the Sonic tools that ship with the drives will be able to create dual-layer discs, which accommodate higher video bit rates and longer movie durations.
Philips will adopt dual-layer DVD+R technology in both desktop and set-top recorders, with the technology likely first appearing in the PC market. First-generation will write dual-layer DVD+R discs at 2.4X speed, according to Clatterbuck.
As for dual-layer's DVD-R implications, Philips intends to propose the format to the DVD Forum after further improvement in performance, which may mean finalization of the 8X spec and availability of 8X-ready drives and media. Pioneer Electronics, developer of the DVD-R/RW format, has also developed dual-layer recording for DVD-R media. They, too, claim that these discs can be played on most existing DVD drives and players (when written in DVD-Video format), but that legacy burners will become read-only when faced with dual-layer media.
The dye-recording film layer method is similar for +R and -R. Both use a silver alloy as the reflector material in the upper layer. Philips claims a reflectivity of at least 18 percent on both layers. Pioneer claims a 17.3 percent reflection rate on layer 0 and a 19.5 percent reflection rate on layer 1. These reflectivity levels ensure compatibility with current DVD standards. Andy Parsons, senior vice president of business solutions for Pioneer, says both formats are "fundamentally pretty similar."
It's hard to say whether dual-layer DVD-R recording will become standard throughout the DVD burning world, Parsons says, but the capability will be there. "Since the engineering changes necessary to support dual-layer recording should not be difficult to achieve, it's likely that this feature could become commonplace in future drives."
Authoring should not be a problem for DVD-R either. Support for dual-layer capacities already exists in high-end authoring tools, so adding the ability to write dual-layer DVD images to DVD recordable media (as opposed to DLT) should come naturally in these environments. "More basic tools would need modifications, of course, but I don't think this should prove very difficult to achieve," says Parsons.
While desktop technology is driving development, set-top technology won't be far behind. Desktop drive components are often also used in set-top video recorders, Parsons says. "There should not be any technical barrier to including dual-layer recording in set-top devices once it's available," he adds. "It's not a question of favoring one over the other. It's just a matter of how desirable the feature will be in a set-top device, and how long it takes to develop procedures for handling tasks like clean layer changes during recording in the video recorder's design."
Set-top video recorders have a lot more to deal with because they are creating an application layer in real time, as opposed to computer-based tools that may do this sequentially over a more extended time.
On the question of price, Parsons says dual-layer DVD-R—much like dual-layer DVD+R—would be about two times the price of single-layer media. Pricing isn't as clear cut for drives, which are still in development. "We don't expect dramatic changes to drive designs, so the cost impact should not be very significant," Parsons says.
Little has been said so far about dual-layer's viability in the rewritable realm, but at least one industry expert isn't holding his breath. "I have my doubts that we'll see much dual-layer recording at all, much less rewritable dual-layer recording," says Rich D'Ambrise, director of technology for Maxell. "People aren't going to want to invest in the hardware to just double capacity."
With blue laser "DVDs" on the roadmap in the BluRay format, some people believe that users will pass over dual-layer DVD for precisely this reason. Of course, the same was said about CD-RW, deemed by some as simply a "bridge technology" between CD and DVD. But here we are, years into DVD recording, and CD-RW is still going strong. Thus it's anybody's guess how—or if—the anticipation for blue laser will inhibit the adoption of dual-layer DVD.