When New Scientist magazine on Monday uncovered a patent filing by three Warner Bros. employees for dual-format optical disc, many saw this development as hope for an end to the format war between HD DVD and Blu-ray Disc. The ongoing format battle hurts both consumers and providers by delaying a single standard for HD content on disc. This announcement provides desperately needed hope for this maddening predicament, but there are a number of questions and reasons for caution. At best, the solution promises to be a half-step forward.

John DiLoreto
Analyst and Editor
of Insight Media

Not to be confused with Toshiba’s recently announced a hybrid DVD/HD DVD disc, the patent, filed in December and published last month, is the first to contain both HD formats. The "multi-layer dual optical disc" technology would store both HD DVD and Blu-ray Disc content on separate single layers. As with the Toshiba hybrid, which uses multiple layers to store both the SD and HD versions of the movie, this new Warner Bros. hybrid can add a third layer for SD DVD or CD content read from the other side of the disc with the usual red laser.

This design requires some tricky optics. Although both HD formats use the same blue (405nm) laser, Blu-ray data is written at 0.1mm from the surface of a disc, while HD-DVD information is written at 0.6mm from the surface. The design contains a Blu-ray top layer backed by a semi-transparent film. Just enough light is reflected for a Blu-ray player to read it okay. Enough light is also transmitted to the next layer to let an HD DVD players see the data image behind the Blu-ray layer.

To see the actual patent, click here.

The downside is that the structure can hold only one layer of each HD format, 25GB for Blu-ray and 15GB for HD DVD (SD DVDs require about 7GB.) With a nominal data rate of 4-6 times that of standard definition, HD content would be limited to a shorter duration than DVDs on this hybrid disc. Another shortcoming is the probable loss of the ability to embed interactive applications and content along with the original movie, which would require more than 25GB.

Yet another shortcoming of the announcement is that a patent is a far cry from a product. Those of us who have led the development of optical components and systems know that a robust, scalable, well performing, cost-effective and widely sold product involves both time and risk of failure. But Warner Bros. did not announce the patent, nor did the applicants reveal their affiliation with Warner, making their intentions to promote or share the technology unclear. So, if Warner Bros. pushes ahead to productize their design, we hope the business executives have the wisdom to license the technology widely, cheaply and quickly.

At best, Warner’s hybrid disc success could help establish both HD DVD and Blu-Ray disc until one format ultimately dominates. But that prospect remains ugly.

Meanwhile, Warner Bros., a backer of both HD formats, will be the first studio to release a film, Lake House on Sept. 26 in all three (DVD, HD DVD and Blu-ray Disc). This format will cost more and acceptance will be based upon the pricing premium (not specified). The studio obviously stands to save a lot by a combined format that requires only one manufacturing run and stores don’t have to stock three versions. We will just have to see how things roll out. –JD