The additional capacity afforded by DVD-R EX, says BeAll's general manager Seong-Joon Kim, makes the media "ideal for two-hour DV tape video transfers, personal backup of DVD-Videos, and especially for DVD games which are sometimes a little larger than regular 4.7GB discs." For content creators authoring DVDs from scratch, the added space accommodates roughly four more minutes of typical-quality audio and video. More sophisticated titles will benefit from less compression, an additional audio track, supplementary material, motion menus, subtitles, or even some DVD-ROM content.
Officially, a blank DVD-R disc (12cm, single-sided, single-layer) offers 4.7GB (i.e., 4.7 billion bytes) of space to store user information. In practice, discs hold a little more than that (4 billion, 7.32 million bytes) and DVD-R EX discs still more (an additional 150 million bytes). BeAll representatives are reluctant to reveal precisely how they achieve this increase but we know that tolerances in the DVD physical format specifications allow for some manufacturing leeway. Tracy Habecker, technical manager at Singulus Mastering, suggests one way to increase disc capacity "is to adjust the end radius of the program area (beyond the usual 58mm)," but there are consequences. "This can cause various playability issues, since the closer you get to the outer edge, the worse the electrical signals." BeAll's Kim also explains, "In our experience, most DVD-R drives have problems performing outer edge recording." DVD-R EX discs avoid these issues, he says, by maintaining a 3mm "buffer zone" at the disc's edge.
According to Habecker, more capacity can also be had by "decreasing the disc's channel bit rate" (scanning velocity), resulting in smaller marks and lands or even by reducing the distance between tracks (track pitch) to expand the total length of the disc's recording groove. Increasing storage capacity while maintaining compatibility with existing drives is "very difficult," says BeAll's Kim, "but after a lot of trial and error we succeeded in optimizing these physical parameters within DVD Forum specifications."
BeAll provided me with sample discs that I ran through a handful of recorders, drives, and players, and all the discs wrote and read successfully. Extensive industry testing has yet to be done. Given the history of optical storage, it's reasonable to assume that DVD-R EX will encounter some of the physical and application compatibility hiccups experienced by early 80-minute CD-R. For example, not all recording hardware or software appears to address DVD-R EX's additional capacity. This was apparent in one of my consumer electronics recorders that wrote the same amount of material to both standard and the enhanced discs.
In professional and corporate circles, writable DVDs are also sometimes used as input sources for duplicating prerecorded DVD-ROMs and non CSS-encrypted DVD-Video titles. In such cases, DVD-R EX discs may prove too big for the job. "A 4.85GB DVD-R filled to capacity would cause problems with the default configurations of DVD physical formatters," says Brad Rickelman, new products manager at premastering and verification pioneer DCA Inc. "The disc manufacturer would have to change the radii points, track pitch, and linear velocity which may cause some playability issues."
An informal survey I conducted of top North American disc manufacturers suggests that most are not looking to offer 4.85GB discs. "We're concentrating on improving features and benefits like scratch- and smudge-resistance and the quality of printable surfaces," says Maxell technical director Rich D'Ambrise. At this stage, DVD-R EX may simply represent the efforts of BeAll looking to differentiate its products, but it's possible that others will eventually follow, taking the same path that saw CD-R discs gradually evolve from 63 to 80 and even 99-minute sizes.
As it stands today, there are a couple of options other than using DVD-R EX to obtain more DVD storage space. The least publicized is "overburning," which squeezes extra capacity out of a standard 4.7GB disc by writing data into its Lead-out zone. According to engineering representatives of Ahead Software, publishers of Nero, a handful of available recorders allow overburning to DVD+R media (I had success using Nero with Plextor PX-708A and PX-712A recorders writing standard MBI discs up to 4.82GB). However, it's not an officially approved practice and carries with it potentially serious playback and data integrity concerns. New 8.5GB DVD+R Double Layer (DL) discs provide another extra-capacity alternative but are very expensive, won't write in older recorders, and have experienced hit-and-miss playback compatibility.
Not the most widely known name in blank disc circles, BeAll is a spin-off of Samsung Electronics and, according to Philips' Intellectual Property and Standards office, is one of three producers currently fabricating DVD-R discs in South Korea. With a declared manufacturing capacity of 2.5 million units per month, BeAll is small by world standards, although it counts among its North American customers such prominent players as Primera Technology, which re-brands BeAll's hub-coated inkjet-printable media.
For more information contact BeAll Developers, Inc. at email@example.com.