GLOSSARY, DVD:           

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AC3: A term synonymous with Dolby Digital, which provides 5+1 Channels of sound. (see 5.1)

Artiface: Something evident in a picture that was not there to begin with. For example, when you watch an AVI or Quicktime movie on your computer, you often see blocky picture elements. Those blocks are artifacts because they were not a part of the original picture. On DVD, artifacts are usually a symptom of poor mastering, poor playback equipment, or improper adjustment of your television monitor. Make sure to calibrate your picture using a test disc like Video Essentials if you feel you are seeing artifacts.

5.1: Shorthand notation for a movie that has five full-range channels of sound and one channel of subwoofer effects. The number to the left of the dot is the number of full range channels and the number to the right of the dot signifies the presence of the dedicated subwoofer channel (also known as LFE). A movie in 5.0 sound has five full range channels and no subwoofer track; a movie in 2.0 sound can be encoded in Dolby Surround or can just be stereo.

Chapter Index: A DVD movie Chapter is similar to a book chapter or a CD track. The Chapter Index allows you to jump to any scene included in the menu (see Interactive Menus.) Your remote should have a button to display the menu. DVD-ROM menu displays vary; sometimes it is shown below the movie window, and sometimes you have to access it through a mouse-click or keystroke. Most menus consist of anywhere between t and 36 scene depictions. These Chapters are displayed as still frame graphics, thumbnails of scenes in action, or simply test links. You can select the Chapter with your remote arrow keys and jump to the chosen scene.

Copy Protection: Both discs and players come equipped with hardware mechanisms to prevent the illegal copying of DVDs. You will not be able to copy the movie to a VHS tape, your computer’s hard drive or any other data –recording device.

Day and Date: Most major movie studios release almost all movies on the same street date as the VHS Video.

Digital Remastering: Stated simply, the quality of the DVD is much higher than that of the same movie on VHS.

DIVX: DIVX is a DVD disc which has been encoded so that you can buy it for $4.50 typically, watch it twice within 48 hours (on a specially equipped player) and then throw it away. Also if you wanted to watch it at a later date you could pay an additional fee and watch it again and again with a fee for each play. This format was available from approvable June of 1997 until July of 1999 and then the backers (mainly Circuit City) quit manufacturing these.

Dolby Digital: An advanced compression method that allows 1 to 5.1 channels of sound to be to be presented on disc. This is the standard sound format that is required on DVD, and it will also be used in future HDTV broadcasts. Audio equipment with a Dolby Digital decoder is required for playback, although all DVD players will "downmix" the signal into two-channel surround if you don't have the DD equipment.

DTS: Digital Theater Systems; a competing multi-channel audio format that also encodes 1 to 5.1 channels of sound for playback on equipment that has a DTS decoder. Common in movie theaters, on laserdisc, and on compact disc, but there are no DTS DVD's yet. A DTS-compatible DVD player will be required for playback of the DTS signal, and only select recent DVD player have this capability.

DVD: Digital Video Disc, or Digital Versatile Disc (or just DVD...the acronym is easier to say, anyway!) a disc the same size as a Music CD or Computer CD which plays Movies or hold a large amount of data. Must be played on a player or computer drive designed to play DVD. 

DVD, More Detail: DVD which once stood for Digital Video Disc or Digital Versatile Disc, is the next generation of optical disc storage technology. It's essentially a bigger, faster CD that can hold video as well as audio and computer data. DVD aims to encompass home entertainment, computers, and business information with a single digital format, eventually replacing audio CD, videotape, laserdisc, CD-ROM, and perhaps even video game cartridges. DVD has widespread support from all major electronics companies, all major computer hardware companies, and all major movie and music studios now support and release almost all movies day and date with the VHS Video.

DVD, What are the features of DVD-Video?

  • Over 2 hours of high-quality digital video (over 8 on a double-sided, dual-layer disc).
  • Support for widescreen movies on standard or widescreen TVs (4:3 and 16:9 aspect ratios).
  • Up to 8 tracks of digital audio (for multiple languages, DVS, etc.), each with as many as 8 channels.
  • Up to 32 subtitle/karaoke tracks.
  • Automatic "seamless" branching of video (for multiple story lines or ratings on one disc).
  • Up to 9 camera angles (different viewpoints can be selected during playback).
  • Menus and simple interactive features (for games, quizzes, etc.).
  • Multilingual identifying text for title name, album name, song name, cast, crew, etc.
  • "Instant" rewind and fast forward, including search to title, chapter, track, and timecode.
  • Durable (no wear from playing, only from physical damage).
  • Not susceptible to magnetic fields. Resistant to heat.
  • Compact size (easy to handle, store, and ship; players can be portable; replication is cheaper).
  • Noncomedogenic.

Note: Most discs do not contain all features (multiple audio/subtitle tracks, seamless branching, parental control, etc.), as each feature must be specially authored. Some discs may not allow searching or skipping.

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DVD, What's the quality of DVD-Video? DVD has the capability to produce near-studio-quality video and better-than-CD-quality audio. DVD is vastly superior to videotape and generally better than laserdisc (see 2.8.). However, quality depends on many production factors. As compression experience and technology improves we will see increasing quality, but as production costs decrease we will also see more shoddily produced discs. A few low-budget DVDs will even use MPEG-1 encoding (which is no better than VHS) instead of higher-quality MPEG-2.

DVD-ROM Compatible: These discs are playable on your computer’s DVD-ROM drive, if equipped with a hardware or software MPEG-2 decoder.

DVD: How should I clean and care for DVDs? Since DVDs are read by a laser, they are resistant—to a point—to fingerprints, dust, smudges, and scratches. However, surface contaminants and scratches can cause data errors. On a video player, the effect of data errors ranges from minor video artifacts to frame skipping to complete unplayability. So it's a good idea to take care of your discs. In general treat them the same way as you would a CD.

Your player can't be harmed by a scratched or dirty disc, unless there are globs of nasty substances on it that might actually hit the lens. Still, it's best to keep your discs clean, which will also keep the inside of your player clean. Never attempt to play a cracked disc, as it could shatter and damage the player. It probably doesn't hurt to leave the disc in the player (even if it's paused and still spinning), but leaving it running unattended for long periods of time is not advisable. 

In general, there's no need to clean the lens on your player, since the air moved by the rotating disc keeps it clean. However, if you commonly use a lens cleaning disc in your CD player, you may want to do the same with your DVD player. I recommend only using a cleaning disc designed for DVD players, since there are minor differences in lens positioning.

Handle only at the hub or outer edge. Don't touch the shiny surface with your popcorn-greasy fingers.

Store in a protective case when not in use. Do not bend the disc when taking it out of the case, and be careful not to scratch the disc when placing it in the case or in the player tray.

Make certain the disc is properly seated in the player tray before you close it. 

Keep away from radiators/heaters, hot equipment surfaces, direct sunlight (near a window or in a car during hot weather), pets, small children, and other destructive forces. Magnetic fields have no effect on DVDs.

Coloring the outside edge of a DVD with a green marker makes no difference in video or audio quality. Data is read based on pit interference at 1/4 of the laser wavelength, or less than 165 nanometers. A bit of dye that on average is more than 3 million times farther away is not going to affect anything.

DVD, Cleaning and repairing DVDs: If you notice problems when playing a disc, you may be able to correct them with a simple cleaning.

  • Do not use strong cleaners, abrasives, solvents, or acids.
  • With a soft, lint-free cloth, wipe gently in only a radial direction (a straight line between the hub and the rim). Since the data is arranged circularly on the disc, the micro scratches you create when cleaning the disc (or the nasty gouge you make with the dirt you didn't see on your cleaning cloth) will cross more error correction blocks and be less likely to cause unrecoverable errors).
  • Don't use canned or compressed air, which can be very cold and may thermally stress the disc.
  • For stubborn dirt or gummy adhesive, use water, water with mild soap, or isopropyl alcohol. As a last resort, try peanut oil. Let it sit for about a minute before wiping it off.
  • There are commercial products that clean discs and provide some protection from dust, fingerprints, and scratches. Cleaning products labeled for use on CDs work as well as those that say they are for DVDs.

If you continue to have problems after cleaning the disc, you may need to attempt to repair one or more scratches. Sometimes even hairline scratches can cause errors if they just happen to cover an entire ECC block. Examine the disc, keeping in mind that the laser reads from the bottom. 


Interactive Menus often consist of the Chapter Index and links to other features on the disc. Selecting them on the Menu can instantly access these extras. The extras may include performers’ bios, movie previews, behind the scenes and virtual playrooms. Interactive Menus may also allow you to select certain settings for the movie, such as language.

Generations of DVD: What's the difference between first, second, and third generation DVD? There is no good answer to this question, since you'll get a different response from everyone you ask. The terms "2nd generation" and "3rd generation" are used refer both to DVD-Video players and to DVD-ROM drives. In general, they simply mean newer versions of basic DVD playback systems. The terms haven't been used (yet) to refer to DVD systems that can record, play video games, or so on.

According to some people, second-generation DVD players came out in the fall of 1997 and third-generation players are those that came out in the beginning of 1998. According to others, the second generation of DVD will be "high-definition" players that won't come out until 2003 or so. There are many confusing variations between these extremes, including the viewpoint that DTS-compatible players or DIVX players or progressive-scan players constitute the third generation.

Things are a little more clear cut on the PC side, where second generation (DVD II) usually means 2x DVD-ROM drives that can read CD-Rs, and third generation (DVD III) usually means 5x (or sometimes 2x or 4.8x or 6x) DVD-ROM drives, a few of which can read DVD-RAMs, and some of which are RPC2 format. See section 4.2 for more speed info. 

LFE: Low Frequency Effects; name given to the dedicated subwoofer channel in Dolby Digital and DTS audio formats.

Multi-angle: What better way to enjoy an adult movie than play cameraman? You choose the angle while you watch. Some DVDs offer nine different viewing angles. Multi-angle is the ultimate use of DVD technology. This feature, however, does not mean that you may change angles throughout the entire movie. Multi-angle scenes have an icon on the screen to let you know that you can change angles.

Parental Lock: Allows you to deny playback of discs or scenes through player mechanisms supported by disc specific content.

Recording on DVD: Short Answer: No. (Not in this century, however this century is almost over.) Long answer: The minimum requirement for reproducing audio and video on DVD is an MPEG video stream and a PCM audio track. (Other streams such as Dolby Digital audio, MPEG audio, and subpicture are not necessary for the simplest case.) Basic DVD control codes are also needed. At the moment it's difficult in real time to encode the video and audio, combine them with DVD-V info, and write the whole thing to DVD. Even if you could do all this in a home recorder, it would be extremely expensive. Prices for DVD production systems are dropping from millions of dollars to thousands of dollars, but they won't be in the <$500 range for home use for several years yet. In June 1997, Hitachi demonstrated a home DVD video recorder containing a DVD-RAM drive, a hard disk drive (as a buffer), two MPEG-1 encoders, and an MPEG-2 decoder. No production date was mentioned. It's possible the first home DVD recorders will require a digital source of already-compressed audio and video, such as DBS.

Other obstacles: Price of blank discs initially will be $30 and up. The first generation of recordable media will hold less than 3/4 as much as prerecorded discs. Real-time compression requires higher bit rates for decent quality, lowering capacity even more. MPEG-2 compression works much better with high-quality source, so recording from VHS or broadcast/cable may not give very good results (unless the DVD recorder has prefilters, which raises the cost).

Regional Coding: What are "regional codes," "country codes," or "zone locks"? A method by which DVD playback is restricted by geographic region. For example, DVD's and DVD players sold in the United States, Canada, and Mexico are usually coded for Region 1. A Region 2 disc from Japan will not play on a Region 1 player, unless that player has been specially modified to do so.

Why are there Regional Codes?:  Motion picture studios want to control the home release of movies in different countries because theater releases aren't simultaneous (a movie may come out on video in the U.S. when it's just hitting screens in Europe). Also, studios sell distribution rights to different foreign distributors and would like to guarantee an exclusive market. Therefore they have required that the DVD standard include codes that can be used to prevent playback of certain discs in certain geographical regions. Each player is given a code for the region in which it's sold. The player will refuse to play discs that are not allowed in that region. This means that discs bought in one country may not play on players bought in another country.

Regional codes are entirely optional for the maker of a disc. Discs without codes will play on any player in any country. It's not an encryption system, it's just one byte of information on the disc that the player checks. Some studios originally announced that only their new releases will have regional codes, but so far almost all releases play in only one region. Region codes are a permanent part of the disc, they won't "unlock" after a period of time.

There are 8 regions (also called "locales"). Players and discs are identified by the region number superimposed on a world globe. If a disc plays in more than one region it will have more than one number on the globe.
1: Canada, U.S., U.S. Territories
2: Japan, Europe, South Africa, Middle East (including Egypt)
3: Southeast Asia, East Asia (including Hong Kong)
4: Australia, New Zealand, Pacific Islands, Central America, Mexico, South America, Caribbean
5: Former Soviet Union, Indian Subcontinent, Africa (also North Korea, Mongolia)
6: China
7: Reserved
8: Special international venues (airplanes, cruise ships, etc.)

Adult DVDs, No Regional Coding: Almost all Adult DVD's do not contain regional coding, so no matter where you are or where your DVD player comes from, you can enjoy Adult top quality DVD titles.

RSDL: Reverse Spiral Dual Layer; a technique by which a movie is split across two layers of a single disc and is joined together for continuous playback. Allows longer movies (or movies with extra content) to be shown uninterrupted on a single side of a disc.

Web Access: At this time Web Access simply means a hyperlink to a website (DVD-ROM) or information about a website (DVD player.) In the near future, this feature will describe interactivity between the DVD and a website.

Glossaries | General | Video &  DVD | Basic Internet Terms | Video & the Internet | Adult | FAQ's | Glossaries