DVD ('Digital Versatile Disc', once 'Digital Video Disc', and now, officially standing for nothing according to DVD Demystified) is an optical disc storage media format that can be used for data storage, including movies with high video and sound quality. DVDs resemble compact discs as their physical dimensions are the same (120 mm (4.72 inches) or occasionally 80 mm (3.15 inches) in diameter) but they are encoded in a different format and at a much higher density. The official DVD specification is maintained by the DVD Forum.

History

In the early 1990s two high-density optical storage standards were being developed: one was the MultiMedia Compact Disc (MMCD), backed by Philips and Sony, and the other was the Super Density disc (SD), supported by Toshiba, Time-Warner, Matsushita Electric, Hitachi, Mitsubishi Electric, Pioneer, Thomson, and JVC. IBM's president, Lou Gerstner, acting as a matchmaker, led an effort to unite the two camps behind a single standard, anticipating a repeat of the costly format war between VHS and Betamax in the 1980s.

Philips and Sony abandoned their MMCD format (not to be confused with MultiMediaCards) and agreed upon Toshiba's SD format (not to be confused with secure digital cards) with two modifications that are both related to the servo tracking technology. The first one was the adoption of a pit geometry that allows 'push-pull' tracking, a proprietary Philips/Sony technology. The second modification was the adoption of Philips' EFMPlus. EFMPlus, created by Kees Immink, who also designed EFM, is 6% less efficient than Toshiba's SD code, which resulted in a capacity of 4.7 GB as opposed to SD's original 5 GB. The great advantage of EFMPlus is its great resilience against disc damage such as scratches and fingerprints. The result was the DVD specification Version 1.5, announced in 1995 and finalized in September 1996. In May 1997, the DVD Consortium was replaced by the DVD Forum, which is open to all companies.

'DVD' was originally an initialism for 'Digital Versatile Disc.' Many non industry consumers believe that it stands for 'Digital Video Disc' however the format was not specifically for video but rather computer data. At the time there were few commercial computer application that would require the size of a DVD, however there was one for video; because video popularized the DVD format consumers mistakenly refer to it as Digital Video Disc.

Warner Home Video and Toshiba introduced the new format to Wall Street types, Hollywood bigwigs and the investment community at an elaborate staged event on the Warner Bros. lot, hosted by Warner Home Video's then president Warren Lieberfarb. The production included the first ever interactive DVD menu designed by producer Billy Pollina. The first DVD players and discs were available in November 1996 in Japan, March 1997 in the United States, 1998 in Europe and in 1999 in Australia. The first pressed DVD release was the film Twister in 1996. The film had the first test for 2.1 surround sound. The first titles released in the U.S., on March 19, 1997, by Lumivision, authored by AIX Entertainment, were IMAX adaptations: Africa: The Serengeti, Antarctica: An Adventure of a Different Nature, Tropical Rainforest, and Animation Greats.

By the early part of 1999 the price of a DVD player had dropped below $300 US. At that point Wal-Mart began to offer DVD players for sale, but DVDs represented only a small part of their video inventory; VHS tapes of films made up the remainder. Wal-Mart's competitors followed suit, and DVDs began to increase in popularity with American consumers.

DVD rentals first topped those of VHS during the week of June 15, 2003 (27.7 M rentals DVD vs. 27.3 M rentals VHS). Major U.S. retailers Circuit City and Best Buy stopped selling pre-recorded VHS tapes in 2002 and 2003, respectively. In June 2005, Wal-Mart and several other retailers announced plans to phase out the VHS format entirely, in favor of the more popular DVD format, however as of late 2006 Wal-Mart still has a very small stock of VHS Movie titles. Blank VHS tapes are still widely available since DVD video recorders are significantly less common than VHS recorders. Many films released to theaters from 2004 onwards are released solely to DVD format and not to VHS format.

While the growth of theatrical films on DVD has cooled recently, that of television programs and music video has increased dramatically. The price of a DVD player has dropped to below the level of a typical VCR (although DVD recorders are still usually more expensive than VCRs); a low-end player with reasonable quality can be purchased for under $35 US in many retail stores and many modern computers are sold with DVD-ROM drives. Also popular are units that have integrated a DVD and VHS VCR into a single device; these can be purchased for under $100 US. Most, but not all, movie 'sets' or series have been released in boxed sets, as have some entire seasons or selected episode volumes of older and newer television programs.

Format in video game consoles

Sony's PlayStation 2, released in 2000, was the first console with a DVD drive; in addition to playing video games, it was also able to play DVD movies. This proved to be a huge selling point and helped boost DVD sales, as the PS2 cost less than most DVD players in Japan. As a result, many electronic stores that normally did not carry video game consoles carried PS2s. Despite many reports of poor and bad playback and green screens, this proved popular and was often used as a primary DVD player until the prices of good standalone players went down.

The DVD drive gave the PS2 an edge over its main rival at the time: Sega's Dreamcast, which instead used a proprietary media called GD-ROM. At a point, Sega displayed a prototype add-on DVD drive for the Dreamcast; however, since it was never showed working, it is frequently rumored that it was just an empty shell. Ultimately, no such unit was ever released. Some stores offered a bundle of the Dreamcast and a regular DVD video player, which helped clear the stock when the Dreamcast was discontinued in 2001.

In keeping with this approach, Sony will incorporate Sony's competing successor to DVD, Blu-ray, into its next console, the PlayStation 3. Problems with implementing this and its Digital Rights Management are the official reason for the delay in launching the system.

Microsoft's Xbox, released in 2001 in the U.S. and on March 13, 2002 in Europe, had the capability to play DVD discs with an add-on remote control kit, cementing DVD's place in video game consoles. Nintendo's GameCube, released on May 3, 2002 in Europe and on November 18, 2001 in the US, cannot play DVDs but uses a proprietary 3-inch optical disc for its game media. However, a version of the GameCube known as the Panasonic Q (sold only in Japan) plays DVDs. With the Xbox 360, the successor to the Xbox, which was released worldwide in November 2005, DVD playback is built in. A HD-DVD Drive add-on is to be be released in late 2006 to play HD-DVD movies. There will be no games released in this format. DVD playback will be available on the upcoming PlayStation 3 as standard, but Nintendo's Wii console, which will use a proprietary 4.5 inch disc for its game media, has been confirmed to be compatible with DVDs at launch, but only in Japan. The Playstation 3 launched in Japan on the 11th of november following the releases in the U.S. in late November 2006 and in Europe in March 2007, with the rest of the world to follow.

Capacity Nomenclature

The four basic types of DVD are referred to by their capacity in gigabytes, rounded up to the nearest integer. The exception to the rule is DVD-18, whose capacity is in fact 17 gigabytes.

Single sided, single layer DVD-5
Single sided, dual layer DVD-9
Double sided, single layer DVD-10
Double sided, dual layer DVD-18

DVD recordable and rewriteable

HP initially developed recordable DVD media from the need to store data for back-up and transport.

DVD recordables are now also used for consumer audio and video recording. Three formats were developed: -R/RW (dash), +R/RW (plus), -RAM (random access memory).

Dual layer recording

Dual Layer recording allows DVD-R and DVD+R discs to store significantly more data, up to 8.5 Gigabytes per disc, compared with 4.7 Gigabytes for single-layer discs. DVD-R DL (dual layer — see figure) was developed for the DVD Forum by Pioneer Corporation, DVD+R DL (double layer — see figure) was developed for the DVD+RW Alliance by Sony.

A Dual Layer disc differs from its usual DVD counterpart by employing a second physical layer within the disc itself; how the drive with Dual Layer capability accesses the second layer is that it could shine the laser through the first semi-transparent layer -- This is something that normal DVD recordable discs do not have. The layer change mechanism in some DVD players can show a noticeable pause, as long as two seconds by some accounts. More than a few viewers have worried that their dual layer discs were damaged or defective.

DVD recordable discs supporting this technology are backward compatible with some existing DVD players and DVD-ROM drives.[citation needed] Many current DVD recorders support dual-layer technology, and the price point is comparable to that of single-layer drives, though the blank media remains significantly more expensive.

DVD-Video

Each DVD-Video disc contains one or more region codes, denoting the area[s] of the world in which distribution and playback are intended. The commercial DVD player specification dictates that a player must only play discs that contain its region code. In theory, this allows the motion picture studios to control the various aspects of a release (including content, date and price) on a region-by-region basis, or ensure the success of 'staggered' or late theatrical releases from country to country. For example, the movie 28 Days Later was released on DVD in Europe several months prior to the film's theatrical release in North America. Regional coding kept the European DVD unplayable for most North American consumers, thereby ensuring that ticket sales would be relatively unaffected by the late theatrical release. To many, this is no more than an objectionable barrier to trade. As a result many websites offer methods with which consumers can by-pass such restrictions.

In practice, many DVD players allow playback of any disc, or can be modified to do so. Entirely independent of encryption, region coding pertains to regional lockout, which originated in the video game industry.

From a worldwide perspective regional coding may be seen as a failure. A huge percentage of players outside of North America can be easily modified (and are even sold pre-modified by mainstream stores such as Amazon.co.uk) to ignore the regional codes on a disc. This, coupled with the fact that almost all televisions in Europe and Australasia are capable of displaying NTSC video, means that consumers in these regions have a huge choice of discs. Contrary to popular belief, this practice is not illegal and in some countries that strongly support free trade (New Zealand is one prominent example) it is encouraged.

A normal DVD player can only play region-coded discs designated for the player's own particular region. However, a code-free or region-free DVD player is capable of playing DVD discs from any of the six regions around the world.

In the US, most low-cost DVD players that are sold in supermarkets or other cheap outlets are not multi-region. Some of the more expensive players (e.g. Sony) are multi-region. Conversely in the UK and Ireland many cheap DVD players are multi-region while more expensive systems, including the majority of home cinema systems, are preset to play only region 2 discs.

DVD-Audio

DVD-Audio is a format for delivering high-fidelity audio content on a DVD. It offers many channel configuration options (from mono to 5.1 surround sound) at various sampling frequencies and sample rates. Compared with the CD format, the much higher capacity DVD format enables the inclusion of either considerably more music (with respect to total running time and quantity of songs) or far higher audio quality (reflected by higher linear sampling rates and higher vertical bit-rates, and/or additional channels for spatial sound reproduction).

Despite DVD-Audio's superior technical specifications, there is debate as to whether or not the resulting audio enhancements are distinguishable to typical human ears. DVD-Audio currently forms a niche market, probably due to its dependency upon new and relatively expensive equipment.

Security

DVD-Audio discs employ a robust copy prevention mechanism, called Content Protection for Prerecorded Media (CPPM) developed by the 4C group (IBM, Intel, Matsushita, and Toshiba).

CPPM can be circumvented on a PC by capturing decoded audio streams in PCM format, but the underlying protection mechanism, encryption algorithms, and keys have not yet been cracked.

Players and recorders

Modern DVD recorders often support additional formats, including DVD+/-R/RW, CD-R/RW, MP3, WMA, SVCD, JPEG, PNG, SVG, KAR and MPEG-4 (DivX/XviD). Some also include USB ports or flash memory readers. Many players are priced from under $/€ 25 and recorders from $/€ 50.

DVD drives for computers usually come with one of two kinds of Regional Playback Control (RPC), either RPC-1 or RPC-2; This is used to enforce the publisher's restrictions on what regions of the world the DVD can be played. See Regional lockout.

Competitors and successors

There are several possible successors to DVD being developed by different consortiums: Sony/Panasonic's Blu-ray Disc (BD), Toshiba's HD DVD and Maxell's Holographic Versatile Disc (HVD).

The first generation of holographic media with 300 GB of storage capacity and a 160 Mbit/s transfer rate is scheduled for release in late 2006 by Maxell and its partner, InPhase.

On November 18, 2003, the Chinese news agency Xinhua reported the final standard of the Chinese government-sponsored Enhanced Versatile Disc (EVD), and several patents for it. However, since then the format has generally failed to live up to expectations.

On November 19, 2003, the DVD Forum decided by a vote of eight to six that HD DVD will be its official HDTV successor to DVD. This had no effect on the competing Blu-ray Disc Association's (BDA) determination that its format would succeed DVD, especially since most of the voters belonged to both groups.

On April 15, 2004, in a co-op project with TOPPAN Printing Co., the electronics giant Sony Corp. successfully developed the paper disc, a storage medium that is made out of 51% paper and offers up to 25 GB of storage, about five times more than the standard 4.7 GB DVD. The disc can be easily cut with scissors and recycled, offering foolproof data security and an environment-friendly storage media.

As reported in a mid 2005 issue of Popular Mechanics, it is not yet clear which technology will win the format war over DVD. HD DVD discs have a lower capacity than Blu-ray discs (15 GB vs. 25 GB for single layer, 30 GB vs. 50 GB for dual layer), but Blu-ray requires changes in manufacturing machinery and techniques and is thus more expensive.

In April, 2000, Sonic Solutions and Ravisent announced hDVD, an HDTV extension to DVD that presaged the HD formats that debuted 6 years later.

This situation—multiple new formats fighting as the successor to a format approaching purported obsolescence—previously appeared as the 'war of the speeds' in the record industry of the 1950s. It is also, of course, similar to the VHS/Betamax war in consumer video recorders in the late 1980s.

It is possible that neither Blu-ray, HD DVD, nor a next-generation optical recording products will succeed. The storage capacities of hard disk drives and solid-state memory have grown faster than those of optical discs (since CD's introduction year, 1983, storage capacity of HDDs grew by a factor of about 150,000, from 5 MB to 750 GB, while the capacity of Blu-ray is only 90 times larger than CD), and all three are much more capable of storing general consumer content —such as photos, music, and video— than in the past. Hard disk drives having a few terabytes of storage capacity will be on the market before 2008. A terabyte is equivalent to about 2000 CD-ROMs, 130 DVD-9s, or 20 dual-layer BDs. However, hard disk drives and memory cards are at the moment hundreds of times more expensive than optical discs (US$50 or more compared to $0.50). The price per gigabyte of a hard disk drive, $0.40 ($200/500 GB), is growing closer to that of a DVD-ROM, $0.06 ($0.50/8.5 GB); BD-ROM, $0.03 ($1.50/50 GB); recordable DVD-5, $0.10 ($0.50/4.7 GB); or recordable DVD-9, $0.30 ($2.50/8.5 GB); and is lower than the cost of a BD-RE25, $1.20 ($30/25 GB). Direct access to large amounts of information is much more convenient with a hard disk drive. As broadband becomes fast enough (40 Mbit/s and higher) and more widely available, physical media will become less important as a distribution format.

One last possibility is that DVD will not be replaced in terms of Home Theatre by any format currently developed. People may not be so keen to upgrade their DVD collection so (relatively) soon. DVD may remain the format of choice for many more years, which may lead to the creation of a better technology that will replace it.

The new generations of optical formats have restricted access (anti-copy mechanisms), and it is therefore possible that consumers may ignore them.


Wikipedia information about DVD. This article is licensed under the GNU Free Documentation License . It uses material from the Wikipedia article 'DVD'