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DVD Primer
(last updated: September 6, 2000)

This DVD Primer is designed as an introduction to DVD. We believe that it answers most basic questions, but if you have suggestions for information to add to the Primer, please contact us at the Secretary Office (Tel: +81-3-5777-2881 Fax: +81-3-5777-2881).










What does DVD mean?

The keyword is "versatile." Digital Versatile discs provide superb video, audio and data storage and access -- all on one disc.

What's the basic difference between DVD and CD?

DVD is a high capacity multimedia data storage medium. It can accommodate a complete movie on a single disc, content rich multimedia or very high quality multi-channel audio.

Can I play CDs on my DVD player?

Most DVD hardware will play audio CDs and CD-ROMs. The physical dimensions are identical to compact discs. But you should check with your DVD brand's dealer to confirm compatibility with CDs.


What's the market outlook for DVD?

The market for DVD has grown faster than CD or VHS did in their first two years in the USA, Europe and Asia.

A recent market research study predicts that DVD will become the standard home video format, replacing video cassettes within the next five years.

Sales of DVD hardware will reach 46 million units in 2000, including 21 million in the United States and 17 million in Europe, according to the report. (The different formats included in this forecast.)

The research also predicts that worldwide shipments of set top DVD players will increase by 300 per cent in 2000 and retail revenues across the United States, Europe and Japan will rise by 220 percent to $7 billion.


How does DVD technology differ from CD?

Like CDs, DVDs store data in microscopic grooves running in a spiral around the disc. All DVD drive types use laser beams to scan these grooves: Minuscule reflective bumps (called lands) and nonreflective holes (called pits) aligned along the grooves represent the zeros and ones of digital information.

But that's where the similarities end. DVDs use smaller tracks (0.74 microns wide, compared to 1.6 microns on CDs) as well as new modulation and error correction methods. These technologies allow them to store data seven times as large as that of a CD. The narrow tracks require special lasers--which can't read CD-ROMs, CD-Rs, CD-RWs, or audio CDs. DVD drive makers managed to solve the problem.


How do the various DVD formats differ?

DVD Video

For viewing movies and other visual entertainment. The total capacity is 17 Gbytes if two layers on both sides of the disk are utilized.


Its basic technology is the same as DVD Video, but it also includes computer-friendly file formats. It is used to store data. This product should supplant conventional CD-ROMs in the near future.


Its capacity is 4.7 Gbytes. Originally designed for professional authoring, a version for general consumer use is now under development. As with CD-R, users can write only once to this disk.


This makes DVD a virtual hard disk, with a random read-write access. Originally a 2.6-Gbyte drive, its capacity has increased to 4.7-Gbyte-per-side. It can be re-written more than 100,000 times.


Similar to DVD-RAM except that its technology features a sequential read-write access more like a phonograph than a hard disk. Its read-write capacity is 4.7 Gbytes per side. It can be re-written up to about 1,000 times.

DVD Audio

The latest audio format more than doubles the fidelity of a standard CD. It is expected to become the most popular audio disk.


Is DVD Multi a new format?

DVD Multi is not a new format, but a set of specifications that will define which drives will read and write which disks for the various DVD consumer and computer applications.

DVD Multi is targeted at providing broader compatibility across DVD disks, and will embrace all existing format versions.


What's the storage capacity of DVD?

A DVD can store over two hours of video on one layer of the disc.

A CD can store just 74 minutes of data -- just enough to hold Beethoven's Ninth Symphony.

Why is DVD video superior to that of standard videotape?

DVD video storage provides resolution which is far greater than that offered by laser disc media and almost twice the resolution of standard VHS videotape.

This resolution is dependent on the capabilities of the television monitor used, but you need not have a new monitor to enjoy the benefits of DVD. DVD video also provides low noise.

One more advantage is that a DVD disc is not physically touched while it spins in the player, so there is no wear and tear or loss of fidelity over time. In contrast, videotapes do touch a playback mechanism and eventually break down, degrading the quality of picture.


How is DVD meeting the needs of various industries?

Movies -- The movie industry needs a disc capable of holding a full length movie of execellent quality video with surround sound audio. DVD Video meets this need.

Computers -- The computer industry needs higher capacity for the increasingly complex multimedia applications which are now being developed. DVD-ROM meets this need. The computer industry also needs new recordable and re-writable versions of DVD for data storage and archival. DVD-RAM and DVD-R meet this need.

Entertainment -- The entertainment industry needs DVD for new video games with better and more realistic video content. DVD-ROM meets this need. The music industry wants a higher quality format than CD, as well as increased playing time. DVD-Audio meets this need.


What's the purpose of the DVD Forum?

DVD Forum is the core DVD industry organization for establishing DVD format standards.

We have eight Working Groups to assure the reliability of DVD hardware and software products and 11 format "Class-A" Verification Laboratories around the world which work closely together to maintain DVD product consistency

Who belongs to the DVD Forum?

Virtually every major company involved in DVD is a member of DVD Forum.

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Updated November 14, 2004

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