Industry agrees on rewritable DVD standards

After negotiations stretching over more than a year, 10 electronics firms from Japan, the U.S. and Europe have finally agreed on standardized DVD formats for rewritable and write-once applications, a consortium of companies said April 14.

The standardization for rewritable DVDs, called DVD-RAM, and for write-once DVDs, known as DVD-R, will help manufacturers develop and sell new large-capacity storage devices for personal computers and audiovisual equipment as early as this year, according to DVD forum officials. DVD is seen as a potential replacement for current compact discs, CD-ROMs, laser discs and even conventional videotapes, and the DVD device market is expected to reach 3 trillion yen by 2000.

“The specifications were optimized following intensive consideration of industry requirements, and with full consideration for compatibility with and the future expandability of the overall DVD format,” the forum said in a statement. The officials said format books explaining the detailed specifications will be issued April 22.

The rewritable DVD, which enables users to store and modify data in addition to playing back prerecorded data, will have a capacity of 2.6 gigabytes for a single-sided disc and double that for a two-sided disc.

The standardized format for rewritable DVD was a compromise between a method endorsed by Matsushita Electric Industrial Co. and Toshiba Corp. and another one backed by Sony Corp. and Philips Electronics NV of the Netherlands. The adopted format, called the “wobble land groove” recording method, will record signals on both the lands, or areas between grooves, and the grooves formed on the disc. Clock data is formed on the track wobbles at the disc manufacturing stage, the forum said.

DVD-R, the write-once disc, can be used as a test disc for developed applications. It has a single-sided storage capacity of 3.95 gigabytes, according to the forum. A two-sided DVD-R has double that capacity. To assure compatibility with other DVD formats, modulation and error correction codes for DVD-RAM and DVD-R are the same as for DVD video and DVD-ROM, which are only for playing back prerecorded data.