Audio Video News

Just a week after a consortium of electronics companies announced its commitment to a new high-capacity DVD, the DVD Forum voted to approve the use of low-bit-rate compression for high-definition DVD. The vote was approved by 11 of the Forum's 17 members, with Matsushita, JVC, and Philips abstaining.

The February 26 vote will officially retain the use of red-laser-based optical discs, despite their larger pit size and resultant lower data capacity—4.7Gigabytes/disc versus the 27Gb/disc promised by "Blu-ray" technology.

The Blu-ray consortium consists of 9 companies—all of them members of the DVD Forum—who want to push forward with the technology as the emerging standard for computer drives and for consumer playback and video recording devices. A capacity of 27Gb is enough to accommodate 13 hours of standard definition television programming, or two hours of ultra-high-definition content.

The use of the MPEG-4 low-bit-rate encoding technology will allow engineers to put as much as 9GB of data, or 40 minutes of high-definition video content onto a two-layer red-laser DVD. The capacity is also sufficient for two full-length movies in 480i. The DVD Forum's technical working group has demonstrated that HD video can be recorded using red lasers and encoding rates as low as 7 Megabits per second (Mbps).

Both moves expand the potential of the DVD, the most successful new format in the history of the electronics industry. The use of low bit-rate compression will push the standard DVD beyond its present limits, while an agreement to develop Blu-ray technology to its maximum potential offers great promise for products to come. "We don't see Blu-ray as replacing DVD; rather, it complements the next-generation DVD format," said Chris Buma, program manager for A/V disk recording at Philips. Some companies have objected to what they see as a needlessly expensive rush into blue-laser technology.

Compatibility issues between the two formats are yet to be resolved. For Blu-ray players and recorders to succeed with consumers, they would need to be backward compatible with red-laser DVDs—including those encoded with MPEG-4. A similar situation faced designers of first-generation DVD players, who wisely chose to make them compatible with audio CDs.