Multiple DVD formats here to say.
Since the introduction of the original audio CD (Compact Disc) in 1982 and the CD-ROM for the computer in 1985, there has been a leap of computing power that has led to a need for even higher quality and greater storage capacity. DVD offers up to 26 times more data storage than the CD, and equivalent to over 11,800 3.5-inch floppy disks. The enormous capacity allows four feature films or about eight hours of theater quality video and multi-channel surround sound audio. One DVD disc can eventually hold up to 17.0 GB of interactive multimedia computer programs, 30 hours of CD audio, or other digital data such as graphics, text, and photos. The growing availability of DVD-ROM drives will soon allow companies to distribute their software applications on a DVD-ROM disc just as CD-ROM is used today.
Today's read-only DVD or the pre-packaged titles available at stores are standardized for compatible playback in DVD players and/or DVD-ROM drives. However, the same statement about standardization cannot be said for write-once or rewritable DVDs.
There are several choices when it comes to writing data from the desktop onto a DVD. If you want to permanently write data to a disc, DVD-R is available today and DVD+R (plus R) is planned for introduction. To write data and then erase or change that data on the same disc, DVD-RAM, DVD-RW, and DVD+RW are available.
But what's best to use and when? With write-once DVD such as DVD-R the disc is written for data permanence. This means that any portion of the disc that contains data can never be erased or overwritten. When a file is revised and resaved, the table of contents of the disc is changed but the disc appends to the existing data already written on the disc. Both DVD formats provide 4.7GB of storage capacity per disc and have a physical disc size of 120mm (same as a CD), but the media cannot be written in the other's drive. From a practical view, the two media formats are identical and once the discs are written, they should be highly compatible with most DVD players or DVD-ROM drives. The main differences between the two media types are that 4.7 GB DVD-R has been shipping for almost a year, while DVD+R is just now under development.
Rewritable DVD offers three format choices: DVD-RAM, DVD-RW, and DVD+RW. DVD-RAM was the first to market in 1998. After three years, it has established itself in several niche markets but has yet to become dominant in the mass market. DVD-RAM can be considered a standalone format. DVD-RAM media is ideal if used in the drive that was used to write data but its low compatibility with DVD-ROM drives and DVD players limits its appeal for data interchange. However, today's DVD-RAM drives also read and write DVD-R to provide for the data interchange function.
DVD-RAM is ideally suited for data storage and is a good candidate for computer system backup and data archiving. DVD-RAM media has data storage capacity of 4.7GB per side (9.4 GB per disc), rewritability up to 100,000 times, sophisticated error correction capability, and superior durability for serious data storage, including jukebox applications. RAM media is available both as a bare disc and in a protective cartridge.
The DVD-RW (referred to as 'RW') format was introduced last year featuring the ability to read and write rewritable RW media as well as popular DVD-R discs. DVD-RW media is a bare disc like today's CD-RW and is highly compatible with drives and players once the files written on it are closed. The downside is in the time it takes to initially format the disc and the higher cost of the disc itself relative to CD-RW. Once the disc is "closed," it reads in most DVD-ROM drives but the user can't expect to use that disc again to edit and add data since all of the data on it must be erased before written to again. Users who want to utilize DVD-RW to store and show home movies or recorded television content, can store fully edited copy and play it on most home DVD players.
DVD+RW (plus RW) is the latest DVD format to come to market but, unlike-RAM and-RW, is not recognized by the standard-setting DVD Forum. Like DVD-RW, the disc must be erased before rewritten and thus for video applications, it cannot be modified after it is "closed," but it is being aimed at the purchaser who requires both data storage and home video playback with the ability to use it in both DVD-ROM drives and DVD players. DVD+R, a write-once version of the +RW format, is now coming to market to satisfy the requirement for data permanence and maximum compatibility for data interchange.
With respect to store-bought, pre-recorded DVD content, it must be emphasized that none of the home recorders or computer writers, no matter the format, will be able to make copies of that material.
Should there be one standard? Probably. But many observers say that there is room for all formats and this may prove true since the applications for writable DVD are in their infancy and their popularity and usefulness will determine whether writable DVD reaches the mainstream. The problem for manufacturers in a world of competing formats is the lack of volume and economics of scale required to produce an affordable solution for the mass market. For now, all of the DVD formats have been adopted by significant computer manufacturers, each for their own reasons. As a result, we won't see a format shake out in the foreseeable future. The challenge, therefore, for companies supporting the DVD market is to provide solutions for all three competing formats. Maxell, for example, is planning to provide write-once and rewritable media to support RAM,-RW, and +RW hardware.
Finally, unlike some technologies and products, where an engineer designs it before the market demands it, DVD is the result of the requests of the movie, broadcast, and computer industries for better quality and greater capacity. Ten years ago, the computer offered simple CGA-based graphics, text-based programming, and simple applications such as calculator and word processing programs. Today, we have 3-D animation, motion video, photo images, high-speed communications, and applications requiring advanced processing such as sophisticated games with full motion video. DVD is a technology that not only keeps pace with today's computing needs, it exceeds them and will satisfy the requirements of future computing and video storage demands, as well.
Rich Gadomski is the director of marketing at Maxell Corporation of America (Fair Lawn, NJ).
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|Title Annotation:||Tape/Disk/Optical Storage|
|Publication:||Computer Technology Review|
|Date:||Feb 1, 2002|
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