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ALL YOUR QUESTIONS ABOUT DVD'S ANSWERED HERE!


DVD Frequently Asked Questions (and Answers)

This is the December 6, 2005 revision of the official Internet DVD FAQ for the rec.video.dvd Usenet newsgroups.
(See below for what's new.) Send corrections, additions, and new questions to Jim Taylor <jtfrog@usa.net>.

This FAQ is usually updated at least once a month. If you are looking at a version more than a month old, it's probably an out-of-date copy. The most current version is at DVD Demystified.

Contents

Recent changes (last posted to newsgroups on Feb 9):

  • 2005-12-06: Renamed "DVD Production" section to "DVD Creation" (5)

  • 2005-12-04: More about adhesive paper labels. Link to templates for printing. (1.44)

  • 2005-12-03: Changed 4.3.10 to "When will dual-layer rewritable DVDs be available?"

  • 2005-11-21: Refer to "next-generation" DVD instead of "HD DVD" (3.13).

  • 2005-11-15: Note about recording DVDs in NTSC or PAL format (5.8).

  • 2005-11-13: New question:
    [1.53] Will x-rays hurt DVDs?

  • 2005-10-13: Changed title of 5.1. Updated CD and DVD replication prices. (5.1).

  • 2005-10-13: Attempted to catch up on latest products and company acquisitions. (5.2, 5.4).

  • 2005-09-26: More on reading -VR format and .VRO files (renamed question). (4.10).

  • 2005-09-18: More about letterboxed video on widescreen TVs. (1.38).

  • 2005-09-09: Clarifications on DVDs playing in black and white or tinted. (1.33).

  • 2005-09-07: More pointers to ECMA standards. (4.3.2, 4.3.3, 4.3.4, 4.3.5).

  • 2005-09-06: New question (renumbered old 4.3.4.1 to 4.3.4.2):
    [4.3.4.1] What are the DVD-RAM cartridge types?

  • 2005-08-29: Updated info about copying discs, including dual-layer discs. (5.9).

  • 2005-07-28: Noted that 6C ("six company") group now has nine companies in it. (6.1).

  • 2005-06-03: Format unification talks still underway. (6.5).

  • 2005-06-03: Dolby TrueHD. (6.5).

  • 2005-05-05: LightScribe in-drive labeling feature (1.44).

  • 2005-05-05: Info about laser focus change during layer switch (1.18 and 1.27).

  • 2005-04-26: New question:
    [3.3.2] What's a MiniDVD?

  • 2005-04-21: BD and HD DVD formats may be unified (6.5).

  • 2005-04-11: Updated link to Adam Barrat's DTS/Dolby info (3.6.2).

  • 2005-04-05: Grammar correction (2.4.12).

  • 2005-04-04: Link to VideoETA for upcoming release info (1.6.2).

  • 2005-03-04: Reduced royalty fees from 6C (6.1).

  • 2005-01-04: Updated statistics on number of DVD titles available (1.6).

  • 2004-11-15: Note about VMD (6.5).

  • 2004-11-15: Minor corrections to CSS section (1.11).

  • 2004-11-01: Over 40,000 DVD titles are now available (1.6).

  • 2004-10-23: Updated info on next-gen formats (3.13).

  • 2004-10-23: Improved PAL/NTSC information. List of major countries/regions and link to a list at remoteviewing.com (1.19).

  • 2004-10-22: Link DVDEnFrancais (6.4.5).

  • 2004-09-13: Link to list of film transfer services at HomeMovieDay.com (5.8).

  • 2004-09-05: Note about problems from multiple DVD players installed (4.6).

  • 2004-09-03: New German translation (0.1).

  • 2004-08-29: New question:
    [4.3.11] What does 2x, 4x, 16x, and so on mean on recordable discs, and which one should I use?

  • 2004-08-29: Updated info on DVD writing speeds (4.2).

  • 2004-08-16: New question:
    [1.12.1] What's the difference between DVD-Audio discs and DVD-Music discs?

  • 2004-08-16: Renamed 1.12 to "What about music on DVD: DVD-Audio and SACD?"

  • 2004-08-13: Added DTS to list of licensors (6.1).

  • 2004-07-27: Updated DVD release stats (1.6).

  • 2004-07-27: Latest guidelines on logo licensing (6.1).

  • 2004-07-23: Updated licensing fees (6.1).

  • 2004-07-19: A bit more info on HDMI for digital audio output (3.1).

  • 2004-07-01: Note about poorly mixed dialog tracks (3.6.5).

  • 2004-05-26: Updated licensing info (6.1).

  • 2004-04-26: Clarified encoding of progressive vs. interlaced source (3.4).

  • 2004-04-16: Fixed dozens of outdated links, removed dozens of dead links.

  • 2004-04-16: Defined NBCA (3.11).

  • 2004-04-15: Minor revisions and updated links on longevity info (3.12).

  • 2004-04-14: New question:
    [3.6.5] Why is the dialog hard to hear?

  • 2004-04-14: Additions to 2-channel audio hookup instructions (3.2).

  • 2004-03-21: Added disc write time column to table of drive speeds (4.2).

  • 2004-03-21: New information on HD formats (3.13).

  • 2004-03-21: Minor additions to D-VHS info (2.17).

  • 2004-03-17: Revised 1.27 and renamed it to "Why does playback sometimes freeze for a second?"

  • 2004-02-22: Links to the Laserdisc Database (2.6 and 2.7).

  • 2004-02-15: Link to Robert's DVD Info pages at their new home (6.4.1).

  • 2004-02-09: Removed CopyLeft T-shirt link since the site is apparently taking orders but not fulfilling them (4.8).

  • 2004-02-07: Removed dead link and added Widescreen Museum link (3.5).

  • 2004-02-07: Pointer to DVDRHelp.com to find players that can play MP3 DVDs (2.4.12).

  • 2004-02-07: Listed more optional features (MP3 DVDs, DivX, etc.) (1.2).

  • 2004-01-24: Link to DVD compatibility report (4.3.1).

  • 2004-01-24: Link to NIST guides to disc care (1.39).

  • 2004-01-24: Updates on DivX, 3ivx, and XviD (2.10).

  • 2004-01-24: A few updates to "laser rot" section (1.24).

  • 2004-01-24: Added a little historical context to laserdisc section (2.6).

  • 2004-01-23: A bit more on video and audio problems. (3.2.2)

  • 2004-01-13: Link to new French translation. (0.1)

  • 2004-01-12: Added note about recordable incompatibility to playback problems. (1.41)

[0] Where can I get the DVD FAQ?

[0.1] Has the DVD FAQ been translated into other languages?

The following translations of the DVD FAQ are available. Translations to a few other languages are in progress.

If you'd like to translate the DVD FAQ into another language (Klingon, anyone?), please contact Jim.

Also see 6.4.5 for DVD info in other languages.

[0.2] This FAQ is too long and technical. Is there a simpler version?

Take a gander at Earl's Famous DVD Technology Exposition Web Page Extravaganza Supreme Deluxe <lonestar.texas.net/~bdub/earl/dvd.htm>.

Or you might prefer The Simpsons' DVD Q&A. (Although Lisa erroneously claims DVD stands for "digital versatile disc" -- who you gonna believe, me or an 8-year old genius?)

[0.3] Is this FAQ any good? Who wrote it? How do I know it's accurate?

Here are a few user comments on the DVD FAQ. If you type "DVD" into Google, this Web site is usually the #1 result. It's the most accurate source of DVD information in this galaxy. If you find something you think is in error, please let Jim know. There's plenty of other good information about DVD on the Internet. Pointers to other DVD sites are scattered throughout the FAQ and in section 6.4.

The DVD FAQ is written by Jim Taylor, the author of DVD Demystified and Everything You Ever Wanted to Know About DVD. Jim has been in the DVD business since before there was a DVD business. He found out about the upcoming DVD format in 1995 and began writing articles to let others know about this amazing new technology. Jim received the 2000 DVD Pro Discus Award for Outstanding Contribution to the Industry, was named one of the 21 most influential DVD executives by DVD Report, was an inaugural inductee into the 2002 Digital Media Hall of Fame, and was named one of the Pioneers of DVD in the October 2003 issue of One to One magazine. Jim has worked with interactive media for over 20 years, developing educational software, laserdiscs, CD-ROMs, Web sites, and DVDs, along with teaching workshops, seminars, and university courses. He writes articles and columns about DVD for publications such as Widescreen Review, serves as President of the DVD Association, and sits on advisory boards of leading-edge companies in the DVD industry. Jim was formerly DVD Evangelist at Microsoft, and is currently Chief of DVD Technology and General Manager of the Advanced Technology Group at Sonic Solutions, the leading developer of DVD authoring systems.

[0.4] How big is this thing?

Since you asked, here are the stats as of Oct, 2005:

Size: 596 KB
Number of words: 71,043
Number of external links: 1,701

If you're wondering why it's all in one big piece instead of broken into smaller pieces that would load faster, the main reason is so you can use the find feature of your browser to easily search the entire FAQ. I realize this causes problems with WebTV browsers. Sorry. I might break it up some day.

[1] General DVD

[1.1] What is DVD?

DVD is the new generation of optical disc storage technology. DVD is essentially a bigger, faster CD that can hold cinema-like video, better-than-CD audio, still photos, and computer data. DVD aims to encompass home entertainment, computers, and business information with a single digital format. It has replaced laserdisc, is well on the way to replacing videotape and video game cartridges, and could eventually replace audio CD and CD-ROM. DVD has widespread support from all major electronics companies, all major computer hardware companies, and all major movie and music studios. With this unprecedented support, DVD became the most successful consumer electronics product of all time in less than three years of its introduction. In 2003, six years after introduction, there were over 250 million DVD playback devices worldwide, counting DVD players, DVD PCs, and DVD game consoles. This was more than half the numbers of VCRs, setting DVD up to become the new standard for video publishing.

It's important to understand the difference between the physical formats (such as DVD-ROM and DVD-R) and the application formats (such as DVD-Video and DVD-Audio). DVD-ROM is the base format that holds data. DVD-Video (often simply called DVD) defines how video programs such as movies are stored on disc and played in a DVD-Video player or a DVD computer (see 4.1). The difference is similar to that between CD-ROM and Audio CD. DVD-ROM includes recordable variations: DVD-R/RW, DVD-RAM, and DVD+R/RW (see 4.3). The application formats include DVD-Video, DVD-Video Recording (DVD-VR), DVD+RW Video Recording (DVD+VR), DVD-Audio Recording (DVD-AR), DVD Stream Recording (DVD-SR), DVD-Audio (DVD-A), and Super Audio CD (SACD). There are also special application formats for game consoles such as Sony PlayStation 2 and Microsoft Xbox.

[1.1.1] What do the letters DVD stand for?

All of the following have been proposed as the words behind the letters DVD.

  • Delayed, very delayed (referring to the many late releases of DVD formats)
  • Diversified, very diversified (referring to the proliferation of recordable formats and other spinoffs)
  • Digital venereal disease (referring to piracy and copying of DVDs)
  • Dead, very dead (from naysayers who predicted DVD would never take off)
  • Digital video disc (the original meaning proposed by some of DVD's creators)
  • Digital versatile disc (a meaning later proposed by some of DVD's creators)
  • Nothing

And the official answer is? "Nothing." The original acronym came from "digital video disc." Some members of the DVD Forum (see 6.1) tried to express that DVD goes far beyond video by retrofitting the painfully contorted phrase "digital versatile disc," but this has never been officially accepted by the DVD Forum as a whole. The DVD Forum decreed in 1999 that DVD, as an international standard, is simply three letters. After all, how many people ask what VHS stands for? (Guess what, no one agrees on that one either.)

[1.2] What are the features of DVD-Video?

  • Over 2 hours of high-quality digital video (a double-sided, dual-layer disc can hold about 8 hours of high-quality video, or 30 hours of VHS quality video).
  • 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, commentaries, 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).
  • On-screen 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 (no "be kind, rewind" stickers and threats on rental discs)
  • Instant search to title, chapter, music 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 than tapes or laserdiscs).
  • 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.

Most players support a standard set of features:

  • Language choice (for automatic selection of video scenes, audio tracks, subtitle tracks, and menus).*
  • Special effects playback: freeze, step, slow, fast, and scan.
  • Parental lock (for denying playback of discs or scenes with objectionable material).*
  • Programmability (playback of selected sections in a desired sequence).
  • Random play and repeat play.
  • Digital audio output (PCM stereo and Dolby Digital).
  • Recognition and output of DTS Digital Surround audio tracks.
  • Playback of audio CDs.

* Must be supported by additional content on the disc.

Some players include additional features:

  • Component video output (YUV or RGB) for higher quality picture.
  • Progressive-scan component output (YUV or RGB) for highest quality analog picture.
  • Digital video output (SDI, 1394, or DVI/HDMI) for perfect digital picture.
  • Six-channel analog output from internal audio decoder (Dolby Digital, DTS, or MLP).
  • Playback of Video CDs or Super Video CDs.
  • Playback of MP3 CDs.
  • Playback of MP3 DVDs.
  • Playback of video files in other formats such as DivX and MPEG-4.
  • Playback of Picture CDs and Photo CDs.
  • Playback of laserdiscs and CDVs.
  • Reverse single frame stepping.
  • Reverse play (normal speed).
  • RF output (for TVs with no direct video input).
  • Multilingual on-screen display.
  • Multiple disc capacity.
  • Digital zoom (2x or 4x enlargement of a section of the picture). This is a player feature, not a DVD disc feature.

[1.3] 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 consumer videotape and generally better than laserdisc (see 2.7.). However, quality depends on many production factors. As compression experience and technology improves we see increasing quality, but as production costs decrease and DVD authoring software becomes widely available we also see more shoddily produced discs. A few low-budget DVDs even use MPEG-1 encoding (which is no better than VHS) instead of higher-quality MPEG-2.

DVD video is usually encoded from digital studio master tapes to MPEG-2 format. The encoding process uses lossy compression that removes redundant information (such as areas of the picture that don't change) and information that's not readily perceptible by the human eye. The resulting video, especially when it is complex or changing quickly, may sometimes contain visual flaws, depending on the processing quality and amount of compression. At average video data rates of 3.5 to 6 Mbps (million bits/second), compression artifacts may be occasionally noticeable. Higher data rates can result in higher quality, with almost no perceptible difference from the master at rates above 6 Mbps. As MPEG compression technology improves, better quality is being achieved at lower rates.

Video from DVD sometimes contains visible artifacts such as color banding, blurriness, blockiness, fuzzy dots, shimmering, missing detail, and even effects such as a face that "floats" behind the rest of the moving picture. It's important to understand that the term "artifact" refers to anything that is not supposed to be in the picture. Artifacts are sometimes caused by poor MPEG encoding, but artifacts are more often caused by a poorly adjusted TV, bad cables, electrical interference, sloppy digital noise reduction, improper picture enhancement, poor film-to-video transfer, film grain, player faults, disc read errors, and so on. Most DVDs exhibit few visible MPEG compression artifacts on a properly configured system.. If you think otherwise, you are misinterpreting what you see.

Some early DVD demos were not very good, but this is simply an indication of how bad DVD can be if not properly processed and correctly reproduced. In-store demos should be viewed with a grain of salt, since most salespeople are incapable of properly adjusting a television set. 

Most TVs have the sharpness set too high for the clarity of DVD. This exaggerates high-frequency video and causes distortion, just as the treble control set too high on a stereo causes the audio to sound harsh. For best quality the sharpness control should be set very low. Brightness should also not be set too high. Some DVD players output video with a black-level setup of 0 IRE (Japanese standard) rather than 7.5 IRE (US standard). On TVs that are not properly adjusted this can cause some blotchiness in dark scenes. There may be an option in the player menu to use standard black level. DVD video has exceptional color fidelity, so muddy or washed-out colors are almost always a problem in the display (or the original source), not in the DVD player or disc.

DVD audio quality is superb. DVD includes the option of PCM (pulse code modulation) digital audio with sampling sizes and rates higher than audio CD. Alternatively, audio for most movies is stored as discrete, multi-channel surround sound using Dolby Digital or DTS audio compression similar to the digital surround sound formats used in theaters. As with video, audio quality depends on how well the processing and encoding was done. In spite of compression, Dolby Digital and DTS can be close to or better than CD quality.

[1.4] What are the disadvantages of DVD?

  • Vagueness of the DVD specification and inadequate testing of players and discs has resulted in incompatibilities. Some movie discs don't function fully (or don't play at all) on some players. (See 1.41)
  • DVD recorders are more expensive than VCRs. (See 1.14 and 4.3)
  • DVD has built-in copy protection and regional lockout. (See 1.11 and 1.10)
  • DVD uses digital compression. Poorly compressed audio or video may be blocky, fuzzy, harsh, or vague. (See 1.3)
  • The audio downmix process for stereo/Dolby Surround may reduce dynamic range. (See 3.6)
  • DVD doesn't fully support HDTV. (See 2.9)
  • Some DVD players and drives can't read CD-Rs. (See 2.4.3)
  • Some DVD players and drives can't read recordable DVDs. (See 4.3.1)
  • Most DVD players and drives can't read DVD-RAM discs. (See 4.3.4)
  • Very few players can play in reverse at normal speed.
  • Variations and options such as DVD-Audio, DVD-VR, and DTS audio tracks are not supported by all players.

[1.5] What DVD players and drives are available?

Some manufacturers originally announced that DVD players would be available as early as the middle of 1996. These predictions were woefully optimistic. Delivery was initially held up for "political" reasons of copy protection demanded by movie studios, but was later delayed by lack of titles. The first players appeared in Japan in November, 1996, followed by U.S. players in March, 1997, with distribution limited to only 7 major cities for the first 6 months. Players slowly trickled in to other regions around the world. Prices for the first players in 1997 were and up. By the end of 2000, players were available for under at discount retailers. In 2003 players became available for under . Six years after the initial launch, close to one thousand models of DVD players were available from over a hundred consumer electronics manufacturers (see 6.2).

Fujitsu supposedly released the first DVD-ROM-equipped computer on Nov. 6 in Japan. Toshiba released a DVD-ROM-equipped computer and a DVD-ROM drive in Japan in early 1997 (moved back from December which was moved back from November). DVD-ROM drives from Toshiba, Pioneer, Panasonic, Hitachi, and Sony began appearing in sample quantities as early as January 1997, but none were available before May. The first PC upgrade kits (a combination of DVD-ROM drive and hardware decoder card) became available from Creative Labs, Hi-Val, and Diamond Multimedia in April and May of 1997.

Today, every major PC manufacturer has models that include DVD-ROM drives. The price difference from the same system with a CD-ROM drive ranges from to (laptops have more expensive drives). Upgrade kits for older computers have been available over the years for to from companies such as Creative Labs, DynaTek, E4 (Elecede), Hi-Val, Leadtek, Margi Systems (for laptops), Media Forte, Pacific Digital, Sigma Designs, Sony, Toshiba, Utobia, and others. For more information about DVDs on computers, including writable DVD drives, see section 4.

Note: If you buy a player or drive from outside your country (e.g., a Japanese player for use in the US) you may not be able to play region-locked discs on it. (See 1.10.)

The first DVD-Audio players were released in Japan by Pioneer in late 1999, but they did not play copy-protected discs. Matsushita (under the Panasonic and Technics labels) first released full-fledged players in July 2000 for to $1,200. DVD-Audio players are now also made by Aiwa, Denon, JVC, Kenwood, Madrigal, Marantz, Nakamichi, Onkyo, Toshiba, Yamaha, and others. Sony released the first SACD players in May 1999 for ,000. Pioneer's first DVD-Audio players released in late 1999 also played SACD. SACD players are now also made by Accuphase, Aiwa, Denon, Kenwood, Marantz, Philips, Sharp, and others. (See 1.12 for more information on DVD-Audio and SACD.)

More information on players and drives:

[1.5.1] Which player should I buy?

There are many good players available. Video and audio performance in all modern DVD players is excellent. Personal preferences, your budget, and your existing home theater setup all play a large role in determining which player is best for you. Unless you have a high-end home theater setup, a player that costs under should be completely adequate. Make a list of things that are important to you (such as ability to play CD-Rs, ability to play Video CDs, 96 kHz/24-bit audio decoding, DTS Digital Out, internal 6-channel Dolby Digital decoder) to help you come up with a set of players. Then try out a few of the players in your price range, focusing on ease of use (remote control design, user interface, front-panel controls). Since there is not a big variation in picture quality and sound quality within a given price range, convenience features play a big part. The remote control, which you'll use all the time, can drive you crazy if it doesn't suit your style.

Some players, especially cheaper models, don't properly play all discs. Before buying a player, you may want to test it with a few complex discs such as The Matrix, The Abyss, Independence Day, and DVD Demystified. See 1.41 for more information.

In certain cases, you might want to buy a DVD PC instead of a standard DVD player, especially if you want progressive video. See 1.40 and 4.1. 

Here are a few questions to ask yourself.

  • Do I want selectable sound tracks and subtitles, multiangle viewing, aspect ratio control, parental/multirating features, fast and slow playback, great digital video, multichannel digital audio, compatibility with Dolby Pro Logic receivers, on-screen menus, dual-layer playback, and ability to play audio CDs? This is a trick question, since all DVD players have all of these features.
  • Do I want DTS audio? If so, look for a player with the "DTS Digital Out" logo. (See 3.6.2.)
  • Do I want to play Video CDs? If so, check the specs for Video CD compatibility. (See 2.4.5.)
  • Do I want to play recordable DVDs? If so, check the specs or compatibility reports for ability to read -R, -RW, +R, and +RW formats . (See 4.3.1.)
  • Do I need a headphone jack?
  • Do I want player setup menus in languages other than English? If so, look for a multilanguage setup feature. (Note: all players support on-disc multilanguage menus.)
  • Do I want to play homemade CD-R audio discs? If so look for the "dual laser" feature. (See 2.4.3.)
  • Do I want to replace my CD player? If so, you might want a changer that can hold 3, 5, or even hundreds of discs.
  • Do I want to play discs from other countries? If so, beware of regions (see 1.10) and TV formats (see 1.19).
  • Do I want to control all my entertainment devices with one remote control? If so, look for a player with a programmable universal remote, or make sure your existing universal remote is compatible with the DVD player.
  • Do I want to zoom in to check details of the picture or get rid of the black letterbox bars? If so, look for players with picture zoom.
  • Do I have a DTV or progressive-scan display? If so, get a progressive-scan player. (See 1.40.)
  • Do I want to play HDCDs? If so, check for the HDCD logo. (See 2.4.13.)
  • Does my receiver have only optical or only coax digital audio inputs? If so, make sure the player has outputs to match. (See 3.2.)
  • Do I care about black-level adjustment?
  • Do I value special deals? If so, look for free DVD coupons and free DVD rentals that are available with many players.

For more information, read hardware reviews at Web sites such as DVDFile or in magazines such as Widescreen Review. You may also want to read about user experiences at Audio Review and in online forums at Home Theater Forum and DVDFile. There's more advice at DVDBuyingGuide and at eCoustics.com, which also has a list of links to reviews on other sites.

See sections 3.1 and 3.2 for specific information on what audio/video connections are needed to fit into your existing setup.

[1.6] What DVD titles are available?

[In the video distribution industry, a title refers to a movie or other production release, like Snow White, or Star Wars, or a boxed edition of a TV series, like Babylon 5 First Season. Titles are collectively referred to as software, not to be confused with computer software.]

DVD started off slowly. Rosy predictions of hundreds of movie titles for Christmas of 1996 failed to materialize. Only a handful of DVD titles, mostly music videos, were available in Japan for the November 1996 launch of DVD. The first feature films on DVD appeared in Japan on December 20 (The Assassin, Blade Runner, Eraser, and The Fugitive from Warner Home Video). By April, 1997 there were over 150 titles in Japan. 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. (Other movies such as Batman and Space Jam had been demonstrated earlier, but were not full versions available for sale.) The Warner Bros. U.S. launch followed on March 24, but was limited to seven cities. Almost 19,000 discs were purchased in the first two weeks of the US launch -- more than expected. InfoTech predicted over 600 titles by the end of 1997 and more than 8,000 titles by 2000. By December 1997, over 1 million individual DVD discs were shipped, representing about 530 titles. By the end of 1999, over 100 million discs had shipped, representing about 5,000 titles. By the end of 2000 there were over 10,000 titles available in the US and over 15,000 worldwide. By the end of 2001 there were about 14,000 titles available in the U.S. By the end of 2002 there were about 23,000 titles available in the U.S. By March 2003, six years after launch, over 1.5 billion copies of DVD titles had been shipped. Compared to other launches (CD, LD, etc.) these are a huge numbers of titles released in a very short time. (Note that these numbers don't include adult titles, which account for an additional 15% or so.) Just over 10,000 new DVD titles were released in 2003, and almost 11,000 came out in 2004, for a total of 42,500 titles (with about 40,300 still available). It would cost you about ,000 to buy one copy of each.

A number of DVD launches in Europe were announced with little follow-through, but DVD began to become established in Europe around the end of 1998. Availability of DVDs in Europe was initially about 18 months to a year behind the U.S., but has shortened over the years to a delay of only a few weeks to a few months.

See 6.3 for a list of Web sites where you can buy or rent DVDs.

There are many databases on the Internet to search for DVD titles. Here are a few of the best:

DVD-Audio started even slower than DVD-Video. The first commercially available DVD-Audio title, Big Phat Band, was released in October 2000 on the Silverline label of 5.1 Entertainment. Major music labels BMG Entertainment, EMI Music, Universal Music, and Warner Music have committed to DVD-Audio titles, although in fall 2001 Universal announced that it would release SACD titles first. As of the end of 2001, just under 200 DVD-Audio titles were available. The first SACD titles were released in Japan in May 1999.

DVD-ROM computer software is slowly appearing. Many initial DVD-ROM titles were only available as part of a hardware or software bundle. IDC predicted that over 13 percent of all software would be available in DVD-ROM format by the end of 1998, but reality didn't meet expectations. In one sense, DVD-ROMs are simply larger faster CD-ROMs and contain the same material. In many cases CD-ROMs are big enough that there's no need to move to DVD-ROMs. But DVD-ROMs can also take advantage of the high-quality video and multi-channel audio capabilities being added to many DVD-ROM-equipped computers.

[1.6.1] Where can I read reviews of DVDs?

The following sites have reviews of at least 800 discs. Also see the list of DVD review sites at Yahoo.

[1.6.2] How do I find out when a movie or TV show will be available on DVD?

First, check one of the lists and databases mentioned in 1.6 to make sure it's not already available. Then check the upcoming release lists at DVD Review,  Laser Scans, and VideoETA (where you can also sign up to be notified when a movie is released). There's also the release list at Image Entertainment. A good source of info about unannounced titles is The Digital Bits Rumor Mill.

[1.6.3] Why isn't my favorite movie on DVD?

There are many factors that determine when a title is released on DVD. Sometimes the director or producer has control over DVD/video release. Other times it's up to the studio marketing group. Often there are issues with rights. For example, a DVD might be available in one country or region but not available in another because different studios have distribution rights in different countries. Studios do listen to customers, so let them know what titles you'd like to see (see 6.2.2).

[1.6.4] How can I find DVDs with specific features or characteristics?

Use one of the searchable databases in 1.6. Select the features you're looking for (anamorphic widescreen, French audio track, Flemish subtitles, and so on). If a database doesn't include the characteristic you're looking for, try a different database.

[1.6.5] Why do some rental stores and retailers not carry widescreen DVDs?

Some rental chains such as Blockbuster and retailers such as Wal-Mart originally carried only fullscreen (pan and scan) versions of movies when both widescreen and fullscreen versions were available. This infuriated many DVD fans, who could never countenance watching a non-widescreen version of a movie on DVD. There was much complaining, including an online petition with over 25,000 signatures. In early 2003 Blockbuster reversed their policy with the following statement: “We made a decision to purchase the majority of titles we bring in on DVD in the widescreen format. We try to follow our customer preferences. As DVD becomes increasingly popular, they become more familiar with the features and with the benefits of letterboxing. They've learned it's a superior format to full-frame." Wal-Mart similarly switched to widescreen versions apparently after realizing that they sold better.

See 3.5 for more about widescreen. See 1.38 for pros and cons of letterboxing.

[1.7] How much do players and drives cost?

Mass-market DVD movie players list for to . (See 1.5 for more information.) DVD-ROM drives and upgrade kits for computers sell for around to . (OEM drive prices are around .)

[1.8] How much do discs cost?

It varies, but most DVD movies list for to with street prices between and , even those with supplemental material. Low-priced movies can be found for under . DVDs have not followed the initial high-rental-price model of VHS.

DVD-ROMs are usually slightly more expensive than CD-ROMs since there is more on them, they cost a bit more to replicate, and the market is smaller. But as the installed base of drives grow, DVD-ROMs will eventually cost about the same as CD-ROMs do today.

The following sites help you find the lowest prices and discount coupons:

[1.9] How is DVD doing? Where can I get statistics?

DVD did not take off quite as fast as some early predictions, but it has sold faster than videotape, CD, and laserdisc. In fact, before its third birthday in March 2000, DVD had become the most successful consumer electronics entertainment product ever.

Here are some predictions:

  • InfoTech (1995): Worldwide sales of DVD players in 1997 will be 800,000. Worldwide sales of DVD-ROM drives in 1997 will be 1.2 million, with sales of 39 million drives in 2000.
  • Toshiba (1996): 100,000 to 150,000 DVD-Video players will be sold in Japan between Nov. 1 and Dec. 31, 1996, and 750,000-1 million by Nov. 1, 1997. (Actual count of combined shipments by Matsushita, Pioneer, and Toshiba was 70,000 in Oct-Dec 1996.) Total worldwide DVD hardware market expected to reach 120 million units in the year 2000. Worldwide settop DVD player market will be 2 million units in the first year, with sales of 20 million in the year 2000.
  • Pioneer (1996): 400,000 DVD-Video players in 1996, 11 million by 2000. 100,000 DVD-Audio players in 1996, 4 million by 2000.
  • InfoTech (1996): 820,000 DVD-Video players in first year, 80 million by 2005.
  • CEMA (1997): 400,000 DVD-Video players in U.S. in 1997, 1 million in 1998.
  • Time-Warner (1996): 10 million DVD players in the U.S. by 2002.
  • Paul Kagan (1997): 800,000 DVD players in the U.S. in 1997, 10 million in 2000, and 40 million in 2006 (43% penetration). 5.6 million discs sold in 1997, 172 million discs in 2000, and 623 million in 2006.
  • C-Cube (1996): 1 million players and drives in 1997.
  • BASES: 3 million DVD-Video players sold in first year, 13 million sold in 6th year.
  • Dataquest (1997): over 33 million shipments of DVD players and drives by 2000.
  • Philips (1996): 25 million DVD-ROM drives worldwide by 2000 (10% of projected 250 million optical drives).
  • Pioneer (1996): 500,000 DVD-ROM drives sold in 1997, 54 million sold in 2000.
  • Toshiba (1996): 120 million DVD-ROM drives in 2000 (80% penetration of 100 million PCs). Toshiba says they will no longer make CD-ROM drives in 2000.
  • IDC (1997): 10 million DVD-ROM drives sold in 1997, 70 million sold in 2000 (surpassing CD-ROM), 118 million sold in 2001. Over 13% of all software available on DVD-ROM in 1998. DVD recordable drives more than 90% of combined CD/DVD recordable market in 2001.
  • AMI (1997): installed base of 7 million DVD-ROM drives by 2000.
  • Intel (1997): 70 million DVD-ROM drives by 1999 (sales will surpass CD-ROM drives in 1998).
  • SMD (1997): 100 million DVD-ROM/RAM drives shipped in 2000.
  • Microsoft (Peter Biddle, 1997): 15 million DVD PCs sold in 1998, 50 million DVD PCs sold in 1999.
  • Microsoft (Jim Taylor, 1998): installed base of 35 million DVD PCs in 1999.
  • Forrester Research (1997): U.S. base of 53 million DVD-equipped PCs by 2002. 5.2% of U.S. households (5 million) will have a DVD-V player in 2002; 2% will have a DVD-Audio player.
  • Yankee Group (Jan 1998): 650,000 DVD-Video players by 1998, 3.6 million by 2001. 19 million DVD-PCs by 2001.
  • InfoTech (Jan 1998): 20 million DVD-Video players worldwide in 2002, 58 million by 2005. 99 million DVD-ROM drives worldwide in 2005. No more than 500 DVD-ROM titles available by the end of 1998. About 80,000 DVD-ROM titles available by 2005.
  • Screen Digest (Dec 1998): 125,000 DVD-Video player in European homes in 1998, 485,000 in 1999, 1 million in 2000.
  • IRMA (Apr 2000): 12 million players will ship worldwide in 2000.
  • Baskerville (Apr 2000): Worldwide spending on DVD software will surpass that of VHS by 2003. There will be a worldwide installed based of 625 million DVD players by 2010 (55% of TV households).
  • Jon Peddie (Jun 2000): Almost 20 million DVD players will be sold in the U.S. in 2004.
  • IDC (July 2000): 70 million DVD players and drives will be sold by year's end.
  • Screen Digest (June 2000): European installed base of DVD-Video players (1998) 0.3m; (1999) 1.5m; (2000) 5.4m; (2003) 47.1m.
  • Japanese Electronics and Information Technologies Association (December 2000): 37 million DVD players worldwide by 2001.
  • DVD Entertainment Group (July 2001): Approximately 30 million DVD players sold in the U.S. by the end of 2001.
  • Understanding & Solutions (April 2002): DVD player penetration in the UK could grow to 70% by 2006 (CD player penetration reached only 50% in the same time period after launch).

Here's reality:

  • 1997
    • 349,000 DVD-Video players shipped in the U.S. (About 200,000 sold into homes.)
    • 900 DVD-Video titles available in the U.S. Over 5 million copies shipped; about 2 million sold.
    • Over 500,000 DVD-Video players shipped worldwide.
    • Around 330,000 DVD-ROM drives shipped worldwide with about 1 million bundled DVD-ROM titles.
    • 60 DVD-ROM titles (mostly bundled).
  • 1998
    • 1,089,000 DVD-Video players shipped in the U.S. (Installed base of 1,438,000.)
    • 400 DVD-Video titles in Europe (135 movie and music titles).
    • 3,000 DVD-Video titles in the U.S. (2000 movie and music titles).
    • 7.2 million DVD-Video discs purchased.
  • 1999
    • 4,019,000 DVD-Video players shipped in the U.S. (Installed base of 5,457,000.)
    • Over 6,300 DVD-Video titles in the U.S.
    • About 26 million DVD-ROM drives worldwide.
    • About 75 DVD-ROM titles available in the U.S.
  • 2000
    • 8.5 million DVD-Video players shipped in the U.S. (Installed base of 13,922,000.)
    • About 46 million DVD-ROM drives worldwide.
    • Over 10,000 DVD-Video titles available in the U.S.
    • Belgium: 100 thousand installed base
    • France: 1.2 million installed base
    • Germany: 1.2 million installed base
    • Italy: 360 thousand installed base
    • Netherlands: 200 thousand installed base
    • Spain: 300 thousand installed base
    • Sweden: 120 thousand installed base
    • Switzerland: 250 thousand installed base
    • UK: 1 million installed base
  • 2001
    • 12.7 million DVD-Video players shipped in the U.S. (Installed base of 26,629,000.)
    • Over 45 million DVD-ROM drives in the U.S.
    • Over 90 million DVD-ROM drives worldwide.
    • UK: 3 million installed base
  • 2002
    • 17 million DVD-Video players shipped in the U.S. (Installed base of 43,718,000.)
    • Over 75 million DVD-ROM drives in the U.S.
    • Over 140 million DVD-ROM drives worldwide.
  • 2003 (fall)
    • 16 million DVD-Video players shipped in the U.S. (Installed base of 73,300,000.)
    • Over 27,000 DVD-Video titles available in the U.S.

For comparison, there were about 700 million audio CD players and 160 million CD-ROM drives worldwide in 1997. 1.2 billion CD-ROMs were shipped worldwide in 1997 from a base of about 46,000 different titles. There were about 80 million VCRs in the U.S. (89% of households) and about 400 million worldwide. 110,000 VCRs shipped in the first two years after release. Nearly 16 million VCRs were shipped in 1998. In 2000 there were about 270 million TVs in the U.S. and 1.3 billion worldwide. When DVD came out in 1997 there were under 3 million laserdisc players in the U.S.

For latest U.S. player sales statistics, see the CEA page at The Digital Bits. Other DVD statistics and forecasts can be found at IRMA, MediaLine, Twice. Industry analyses and forecasts can be purchased from Adams Media Research, Alexander & Associates, British Video Association, Cahners In-stat, Centris, Datamonitor, Dataquest, DVD Intelligence, eBrain, International Data Corporation (IDC), InfoTech, Jon Peddie Associates (JPA), Paul Kagan Associates, Screen Digest, SIMBA Information, Strategy Analytics, Understanding & Solutions and others.

[1.10] What are "regional codes," "country codes," or "zone locks"?

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 required that the DVD standard include codes 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 coded for its region. This means that a disc bought in one country may not play on a player bought in another country. Some people believe that region codes are an illegal restraint of trade, but no legal cases have established this.

Regional codes are entirely optional for the maker of a disc. Discs without region locks 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 would have regional codes, but so far almost all Hollywood releases play in only one region. Region codes are a permanent part of the disc, they won't "unlock" after a period of time. Region codes don't apply to DVD-Audio, DVD-ROM, or recordable DVD (see below for more detail).

Seven regions (also called locales or zones) have been defined, and each one is assigned a number. Players and discs are often identified by their 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: U.S., Canada, U.S. Territories
2: Japan, Europe, South Africa, and Middle East (including Egypt)
3: Southeast Asia and East Asia (including Hong Kong)
4: Australia, New Zealand, Pacific Islands, Central America, Mexico, South America, and the Caribbean
5: Eastern Europe (Former Soviet Union), Indian subcontinent, Africa, North Korea, and Mongolia
6: China
7: Reserved
8: Special international venues (airplanes, cruise ships, etc.)
(See the map at <www.blackstar.co.uk/help/help_dvd_regions>.)

Technically there is no such thing as a region zero disc or a region zero player. There is such thing as an all-region disc. There are also all-region players. Some players can be "hacked" using special command sequences from the remote control to switch regions or play all regions. Some players can be physically modified ("chipped") to play discs regardless of the regional codes on the disc. This usually voids the warranty, but is not illegal in most countries (since the only thing that requires player manufacturers to region-code their players is the CSS license; see 1.11). Many retailers, especially outside North America, sell players that have already been modified for multiple regions, or in some cases they simply provide instructions on how to access the "secret" region change features already built into the player. As an interesting side note, on Feb. 7, 2001, NASA sent two multiregion DVD players to the International Space Station.

Extensive information about modifying players and buying region-free players can be found on the Internet (see 6.4.2).

In addition to region codes, there are also differences in discs for NTSC and PAL TV systems (see 1.19).

Some discs from Fox, Buena Vista/Touchstone/Miramax, MGM/Universal, Polygram, and Columbia TriStar contain program code that checks for the proper region setting in the player. (There's Something About Mary and Psycho are examples.) In late 2000, Warner Bros. began using the same active region code checking that other studios had been using for over a year. They called it "region code enhancement" (RCE, also known as REA), and it received much publicity. RCE was first added to discs such as The Patriot and Charlie's Angels. "Smart discs" with active region checking won't play on code-free players that are set for all regions (FFh), but they can be played on manual code-switchable players that allow you to use the remote control to change the player's region to match the disc. They may not work on auto-switching players that recognize and match the disc region. (It depends on the default region setting of the player. An RCE disc has all its region flags set so that the player doesn't know which one to switch to. The disc queries the player for the region setting and aborts playback if it's the wrong one. A default player setting of region 1 will fool RCE discs from region 1. Playing a region 1 disc for a few seconds sets most auto-switching players to region 1 and thus enables them to play an RCE disc.) When an RCE disc detects the wrong region or an all-region player, it will usually put up a message saying that the player may have been altered and that the disc is not compatible with the player. A serious side effect is that some legitimate players fail the test, such as the Fisher DVDS-1000.

There was much wailing and gnashing of teeth when RCE first appeared, but DVD fans quickly learned that it only affected some players. Makers of player modification kits that didn't work with RCE soon improved their chips to get around it. For every higher wall there is a taller ladder. See DVDTalk's RCE FAQ for more info and workarounds.

In general, region codes don't apply to recordable DVDs. A DVD that you make on a PC with a DVD burner or in a home DVD video recorder will play in all regions (but don't forget NTSC vs. PAL differences, see 1.19). Region codes do not apply to DVD-Audio.

Regional codes apply to game consoles such as PlayStation 2 and Xbox, but only for DVD-Video (movie) discs (see DVDRegionX for region modifications to PS2). PlayStation has a separate regional lockout scheme for games. Regional codes also apply to DVD-ROM computers, but affect only DVD-Video discs, not DVD-ROM discs containing computer software. Computer playback systems check for regional codes before playing movies from a CSS-protected DVD-Video (see 1.11 for CSS info). Newer RPC2 DVD-ROM drives let you change the region code several times. (RPC stands for region protection control.) Once an RPC2 drive has reached the limit of 5 changes it can't be changed again unless the vendor or manufacturer resets the drive. The Drive Info utility can tell you if you have an RPC2 drive (it will say "This drive has region protection"). See 6.4.2 for links to more information about circumventing DVD-ROM region restrictions. Since December 31, 1999, only RPC2 drives have been manufactured.

[1.11] What are the copy protection issues?

CPSA (content protection system architecture) is the name given to the overall framework for security and access control across the entire DVD family. Developed by the "4C" entity (Intel, IBM, Matsushita, and Toshiba) in cooperation with the Copy Protection Technical Working Group (CPTWG), it covers encryption, watermarking, protection of analog and digital outputs, and so on. There are many forms of content protection that apply to DVD.

1) Analog CPS (Macrovision)
Videotape (analog) copying is prevented with a Macrovision 7.0 or similar circuit in every player. Macrovision may show up as stripes of color, distortion, rolling, black & white picture, and dark/light cycling. Macrovision creates problems for most TV/VCR combos (see 3.2.1) and some high-end equipment such as line doublers and video projectors.

The general term for a system that prevents taping is APS (Analog Protection System), also sometimes called copyguard. Computer video cards with composite or s-video (Y/C) output must also use APS. Macrovision changes the composite video and s-video output in two ways: the Colorstripe technique creates a rapidly modulated colorburst signal, and the AGC technique inserts pulses in the vertical blanking signal. This confuses the synchronization and automatic-recording-level circuitry in 95% of consumer VCRs. Unfortunately, it can degrade the picture, especially with old or nonstandard equipment. Macrovision was not present on analog component video output of early players, but is now required on component output (AGC only, since there is no burst in a component signal).

The discs themselves contain "trigger bits" telling the player whether or not to enable Macrovision AGC, with the optional addition of 2-line or 4-line Colorstripe. The triggers occur about twice a second, which allows fine control over what part of the video is protected. The producer of the disc decides what amount of copy protection to enable and then pays Macrovision royalties accordingly (several cents per disc). Just as with videotapes, some DVDs are Macrovision-protected and some aren't. (For a few Macrovision details see STMicroelectronics' NTSC/PAL video encoder datasheets at <www.st.com/stonline/books/>.)

Inexpensive devices can defeat Macrovision, although only a few work against the more recent Colorstripe feature. These devices go under names such as DVD Red, Video Clarifier, Image Stabilizer, Color Corrector, DVD Red, and CopyMaster. Or you can build your own. Some DVD players can be modified to turn off Macrovision output (see 6.4.2). Professional time-base correctors (TBCs) that regenerate line 21 also remove Macrovision. APS affects only video, not audio.

2) CGMS
Each disc contains information specifying if the contents can be copied. This is a serial copy generation management system (SCMS) designed to prevent initial copies or generational copies (copies of copies). The CGMS information is embedded in the outgoing video signal. For CGMS to work, the equipment making the copy must recognize and respect the CGMS information. The analog standard (CGMS-A) encodes the data on NTSC line 21 (in the XDS service) or line 20. CGMS-A is recognized by most digital camcorders and by some computer video capture cards (they will flash a message such as "recording inhibited"). Professional time-base correctors (TBCs) that regenerate lines 20 and 21 will remove CGMS-A information from an analog signal. The digital standard (CGMS-D) is included in DTCP and HDMI for digital connections such as IEEE 1394/FireWire. See subsections 6 and 7 below.

3) Content Scramble System (CSS)
Because of the potential for perfect digital copies, paranoid movie studios forced a deeper copy protection requirement into the DVD standard. Content Scramble System (CSS) is a data encryption and authentication scheme intended to prevent copying video files directly from DVD-Video discs. CSS was developed primarily by Matsushita and Toshiba. Each CSS player licensee is given a key from a master set of 409 keys stored on every CSS-encrypted disc. The theory was to allow a license to be revoked by removing its key from future discs. The CSS decryption algorithm exchanges keys with the drive unit to generate an encryption key that is then used to obfuscate the exchange of disc keys and title keys that are needed to decrypt data from the disc. DVD players have CSS circuitry that decrypts the data before it's decoded and displayed, and computer DVD decoder hardware and software must include a CSS decryption module. All DVD-ROM drives have extra firmware to exchange authentication and decryption keys with the CSS module in the computer. As of 2000 DVD-ROM drives are required to support regional management in conjunction with CSS (see 1.10 and 4.1). Makers of equipment used to display DVD-Video (drives, decoder chips, decoder software, display adapters, etc.) must license CSS. There is an annual ,000 fee for the CSS license, and qualification is a lengthy process, so it's recommended that interested parties apply early. CSS is administered by the DVD Copy Control Association (DVD CCA). Near the end of May 1997, CSS licenses were finally granted for software decoding. The license is extremely restrictive in an attempt to keep the CSS algorithm and keys secret. Of course, nothing that's used on millions of players and drives worldwide could be kept secret for long. In October 1999, the CSS algorithm was cracked and posted on the Internet, triggering endless controversies and legal battles (see 4.8).

4) Content Protection for Prerecorded Media (CPPM)
CPPM is used only for DVD-Audio. It was developed as an improvement on CSS. Keys are stored in the lead-in area, but unlike CSS no title keys are placed in the sector headers. Each volume has a 56-bit album identifier, similar to a CSS disc key, stored in the control area. Each disc contains a media key block, stored in a file in the clear on the disc. The media key block data is logically ordered in rows and columns that are used during the authentication process to generate a decryption key from a specific set of player keys (device keys). As with CSS, the media key block can be updated to revoke the use of compromised player keys. If the device key is revoked, the media key block processing step will result in an invalid key value. The authentication mechanism is the same as for CSS, so no changes are required to existing drives. A disc may contain both CSS and CPPM content if it is a hybrid DVD-Video/DVD-Audio disc.

5) Content Protection for Recordable Media (CPRM)
CPRM is a mechanism that ties a recording to the media on which it is recorded. It is supported by some DVD recorders, but not by many DVD players. Each blank recordable DVD has a unique 64-bit media ID etched in the BCA (see 3.11). When protected content is recorded onto the disc, it can be encrypted with a 56-bit C2 (Cryptomeria) cipher derived from the media ID. During playback, the ID is read from the BCA and used to generate a key to decrypt the contents of the disc. If the contents of the disc are copied to other media, the ID will be absent or wrong and the data will not be decryptable.

6) Digital Copy Protection System (DCPS)
In order to provide digital connections between components without allowing perfect digital copies, five digital copy protection systems were proposed to the CEA. The frontrunner is DTCP (digital transmission content protection), which focuses on IEEE 1394/FireWire but can be applied to other protocols. The draft proposal (called 5C, for the five companies that developed it) was made by Intel, Sony, Hitachi, Matsushita, and Toshiba in February 1998. Sony released a DTCP chip in mid 1999. Under DTCP, devices that are digitally connected, such as a DVD player and a digital TV or a digital VCR, exchange keys and authentication certificates to establish a secure channel. The DVD player encrypts the encoded audio/video signal as it sends it to the receiving device, which must decrypt it. This keeps other connected but unauthenticated devices from stealing the signal. No encryption is needed for content that is not copy protected. Security can be "renewed" by new content (such as new discs or new broadcasts) and new devices that carry updated keys and revocation lists (to identify unauthorized or compromised devices). A competing proposal, XCA (extended conditional access), from Zenith and Thomson, is similar to DTCP but can work with one-way digital interfaces (such as the EIA-762 RF remodulator standard) and uses smart cards for renewable security. Other proposals have been made by MRJ Technology, NDS, and Philips. In all five proposals, content is marked with CGMS-style flags of "copy freely", "copy once," "don't copy," and sometimes "no more copies". Digital devices that do nothing more than reproduce audio and video will be able to receive all data (as long as they can authenticate that they are playback-only devices). Digital recording devices are only able to receive data that is marked as copyable, and they must change the flag to "don't copy" or "no more copies" if the source is marked "copy once." DCPSes are designed for the next generation of digital TVs, digital receivers, and digital video recorders. They require new DVD players with digital connectors (such as those on DV equipment). These new products began to appear in 2003. Since the encryption is done by the player, no changes are needed to existing discs.

7) High-Bandwidth Digital Content Protection (HDCP, DVI, and HDMI)
HDCP is similar to DTCP, but it was designed for digital video monitor interfaces. In 1998, the Digital Display Working Group (DDWG) was formed to create a universal interface standard between computers and displays to replace the analog VGA connection standard. The resulting Digital Visual Interface (DVI) specification, released in April 1999, was based on Silicon Image's PanelLink technology, which at 4.95 Gbps can support 1600×1200 (UXGA) resolution, which covers all the HDTV resolutions. Intel proposed HDCP as a security component for DVI. A new connection standard called HDMI combines DVI and HDCP. DVD players with DVI or HDMI digital video output appeared in spring 2003. Many new HDTV displays are likely to have both IEEE 1394 and HDMI connections.

HDCP provides authentication, encryption, and revocation. Specialized circuitry in the playback device and in the display monitor encrypts video data before it is sent over the link. When an HDMI output senses that the connected monitor does not support HDCP, it lowers the image quality of protected content. The HDCP key exchange process verifies that a receiving device is authorized to display or record video. It uses an array of forty 56-bit secret device keys and a 40-bit key selection vector -- all supplied by the HDCP licensing entity. If the security of a display device is compromised, its key selection vector is placed on the revocation list. The host device has the responsibility of maintaining the revocation list, which is updated by system renewability messages (SRMs) carried by newer devices and by video content. Once the authority of the receiving device has been established, the video is encrypted by an exclusive-or operation with a stream cipher generated from keys exchanged during the authentication process. If a display device with no decryption ability attempts to display encrypted content, it appears as random noise.

 

The first four forms of copy protection (Macrovision, CGMS, CSS, and CPPM) are optional for the producer of a disc. CSS decryption is optional for hardware and software playback manufacturers, although a player or computer without decryption capability will only be able to play unencrypted movies. CPRM is handled automatically by DVD recorders, although it's optional and many recorders don't support it. DTCP and HDCP are handled by DVD players with digital video outputs.

These copy protection schemes are designed only to guard against casual copying (which the studios claim causes billions of dollars in lost revenue). The goal is to "keep the honest people honest." The people who developed the copy protection standards are the first to admit they can't stop well-equipped pirates.

Movie studios have promoted legislation making it illegal to defeat DVD copy protection. The result is the World Intellectual Property Organization (WIPO) Copyright Treaty and the WIPO Performances and Phonograms Treaty (December 1996) and the compliant U.S. Digital Millennium Copyright Act (DMCA), passed into law in October 1998. Software intended specifically to circumvent copy protection is now illegal in the U.S. and many other countries. A co-chair of the legal group of the DVD copy protection committee stated, "in the video context, the contemplated legislation should also provide some specific assurances that certain reasonable and customary home recording practices will be permitted, in addition to providing penalties for circumvention." It's not at all clear how this might be "permitted" by a player or by studios that routinely set the "don't copy" flag on all their discs.

DVD-ROM drives and computers, including DVD-ROM upgrade kits, are required to support Macrovision, CGMS, and CSS. PC video cards with TV outputs that don't support Macrovision will not work with encrypted movies. Computers with IEEE 1394/FireWire connections must support the final DCPS standard in order to work with other DCPS devices. Likewise computers with HDMI (DVI) connections must support HDCP to output DVD-Video content. Every DVD-ROM drive must include CSS circuitry to establish a secure connection to the decoder hardware or software in the computer, although CSS can only be used on DVD-Video content. Of course, since a DVD-ROM can hold any form of computer data, other encryption schemes can be implemented. See 4.1 for more information on DVD-ROM drives.

The Watermarking Review Panel (WaRP) --the successor to the Data-Hiding Sub-Group (DHSG)-- of the CPTWG selected an audio watermarking system that has been accepted by the DVD Forum for DVD-Audio (see 1.12). The original seven video watermarking proposals were merged into three: IBM/NEC, Hitachi/Pioneer/Sony, and Macrovision/Digimarc/Philips. On February 17, 1999, the first two groups combined to form the "Galaxy Group" and merged their technologies into a single proposal. The second group has dubbed their technology "Millennium." Watermarking permanently marks each digital audio or video frame with noise that is supposedly undetectable by human ears or eyes. Watermark signatures can be recognized by playback and recording equipment to prevent copying, even when the signal is transmitted via digital or analog connections or is subjected to video processing. Watermarking is not an encryption system, but rather a way to identify whether a copy of a piece of video or audio is allowed to be played. New players and software are required to support watermarking, but the DVD Forum intends to make watermarked discs compatible with existing players. Reports were made that the early watermarking technique used by Divx caused visible "raindrop" or "gunshot" patterns, but the problem was apparently solved for later releases.

[1.12] What about music on DVD: DVD-Audio and SACD?

Note: Don't confuse DVD-Audio with DVD-Music (see 1.12.1).

When DVD was released in 1996 there was no DVD-Audio format, although the audio capabilities of DVD-Video far surpassed CD. The DVD Forum sought additional input from the music industry before defining the DVD-Audio format. A draft standard was released by the DVD Forum's Working Group 4 (WG4) in January 1998, and version 0.9 was released in July. The final DVD-Audio 1.0 specification (minus copy protection) was approved in February 1999 and released in March, but products were delayed in part by the slow process of selecting copy protection features (encryption and watermarking), with complications introduced by the Secure Digital Music Initiative (SDMI). The scheduled October 1999 release was further delayed until mid 2000, ostensibly because of concerns caused by the CSS crack (see 4.8), but also because the hardware wasn't quite ready, production tools weren't up to snuff, and there was lackluster support from music labels. Pioneer released the first DVD-Audio players (without copy protection support) in Japan in late 1999.

Matsushita released Panasonic and Technics brand universal DVD-Audio/DVD-Video players in July 2000 for to $1,200. Pioneer, JVC, Yamaha, and others released DVD-Audio players in fall 2000 and early 2001. By the end of 2000 there were about 50 DVD-Audio titles available. By the end of 2001 there were just under 200 DVD-Audio titles available.

DVD-Audio is a separate format from DVD-Video. DVD-Audio discs can be designed to work in DVD-Video players, but it's possible to make a DVD-Audio disc that won't play at all in a DVD-Video player, since the DVD-Audio specification includes new formats and features, with content stored in a separate "DVD-Audio zone" on the disc (the AUDIO_TS directory) that DVD-Video players never look at. New DVD-Audio players are needed, or new "universal players" that can play both DVD-Video and DVD-Audio discs. Universal players are also called VCAPs (video-capable audio players).

A plea to producers: Universal players are rare, but you can make universal discs easily. With a small amount of effort, all DVD-Audio discs can be made to work on all DVD players by including a Dolby Digital version of the audio in the DVD-Video zone.

A plea to DVD-Audio authoring system developers: Make your software do this by default or strongly recommend this option during authoring.

DVD-Audio players (and universal players) work with existing receivers. They output PCM and Dolby Digital, and some will support the optional DTS and DSD formats. However, most current receivers can't decode high-definition, multichannel PCM audio (see 3.6.1 for details), and even if they could it can't be carried on standard digital audio connections. DVD-Audio players with high-end digital-to-analog converters (DACs) can only be hooked up to receivers with 2-channel or 6-channel analog inputs, but some quality is lost if the receiver converts back to digital for processing. New receivers with improved digital connections such as IEEE 1394 (FireWire) are needed to use the full digital resolution of DVD-Audio.

DVD audio is copyright protected by an embedded signaling or digital watermark feature. This uses signal processing technology to apply a digital signature and optional encryption keys to the audio in the form of supposedly inaudible noise so that new equipment will recognize copied audio and refuse to play it. Proposals from Aris, Blue Spike, Cognicity, IBM, and Solana were evaluated by major music companies in conjunction with the 4C Entity, comprising IBM, Intel, Matsushita, and Toshiba. Aris and Solana merged to form a new company called Verance, whose Galaxy technology was chosen for DVD-Audio in August 1999. (In November 1999, Verance watermarking was also selected for SDMI.) Verance and 4C claimed that tests on the Verance watermarking method showed it was inaudible, but golden-eared listeners in later tests were able to detect the watermarking noise.

Sony and Philips have developed a competing Super Audio CD format that uses DVD discs. (See 3.6.1 for details.) Sony released version 0.9 of the SACD spec in April 1998, the final version appeared in April (?) 1999. SACD technology is available to existing Sony/Philips CD licensees at no additional cost. Most initial SACD releases have been mixed in stereo, not multichannel. SACD was originally supposed to provide "legacy" discs with two layers, one that plays in existing CD players, plus a high-density layer for DVD-Audio players, but technical difficulties kept dual-format discs from being produced until the end of 2000, and only then in small quantities. Pioneer, which released the first DVD-Audio players in Japan at the end of 1999, included SACD support in their DVD-Audio players. If other manufacturers follow suit, the entire SACD vs. DVD-Audio standards debate could be moot, since DVD-Audio players would play both types of discs.

Sony released an SACD player in Japan in May 1999 at the tear-inducing price of ,000. The player was released in limited quantities in the U.S. at the end of 1999. Philips released a ,500 player in May 2000. Sony shipped a SACD player in Japan in mid 2000. About 40 SACD titles were available at the end of 1999, from studios such as DMP, Mobile Fidelity Labs, Pioneer, Sony, and Telarc. Over 500 SACD titles were available by the end of 2001.

A drawback related to DVD-Audio and SACD players is that most audio receivers with 6 channels of analog input aren't able to do bass management. Receivers with Dolby Digital and DTS decoders handle bass management internally, but 6-channel analog inputs are usually passed straight through to the amplifier. Without full bass management on 6-channel analog inputs, any audio setup that doesn't have full-range speakers for all 5 surround channels will not properly reproduce all the bass frequencies.

If you are interested in making the most of a DVD-Audio or SACD player, you need a receiver with 6-channel analog audio inputs. You also need 5 full-frequency speakers (that is, each speaker should be able to handle subwoofer frequencies) and a subwoofer, unless you have a receiver that can perform bass management on the analog inputs, or you have an outboard bass management box such as from Outlaw Audio.

For more on DVD-Audio, including lists of titles and player models, visit Digital Audio Guide.

[1.12.1] What's the difference between DVD-Audio discs and DVD-Music discs?

DVD-Music isn't actually an official DVD format, but it has become a commonly used name for a DVD-Video disc that contains primarily music. A DVD-Music disc plays in any standard DVD player with video or still pictures that accompany the audio. As explained in 1.12, a DVD-Audio disc contains special high-fidelity audio tracks that can only be played in DVD-Audio players.

[1.13] Which studios support DVD?

All major movie studios and most major music labels support DVD.

When DVD players became available in early 1997, Warner and Polygram were the only major movie studios to release titles. Additional titles were available from small publishers. The other studios gradually joined the DVD camp (see 6.2 for a full list, see 1.6 for movie info). Dreamworks was the last significant studio to announce full DVD support. Paramount, Fox, and Dreamworks initially supported only Divx, but in summer 1998 they each announced support for open DVD.

[1.14] Can DVD record from TV/VCR/etc?

Yes, if you have a DVD recorder. When DVD was originally introduced in 1997, only players were available. Most DVD units sold today are still play-only, but recorders are becoming more widespread and more affordable. DVD video recorders first appeared in Japan at the end of 1999, and in the rest of the world at the end of 2000. Early units were expensive: ,500 to ,000. DVD video recorders are still expensive (typically to as of mid 2005), but eventually will be as cheap as VCRs. DVD recorders are being added to satellite and cable receivers, hard-disk video recorders, and other advanced consumer electronics devices.

A DVD recorder works like a VCR -- it has a tuner and A/V inputs, and it can be programmed to record shows. An important difference is that you never have to rewind or fast forward -- recordings on a disc are instantly accessible, usually from an on-screen menu. Many DVD recorders include an electronic program guide (EPG) that gives you onscreen TV listings from which you can pick shows to record (no need to enter day, time, channel, and so on by hand).

Note that DVD video recorders can't copy most DVD movie discs, which are protected.

Unfortunately there is more than one recordable DVD format, and they don't all play together nicely. It's nothing like the old "VHS vs. Betamax battle" as many in the press would have you believe, but it is rather confusing. See 4.3 to get more confused.

Don't be further confused by DVD recordable drives (DVD burners) for computers (see 4.3). These recorders can store data, but to create full-featured DVD-Videos requires additional software to do video encoding (MPEG), audio encoding (Dolby Digital, MPEG, or PCM), navigation and control data generation, and so on (see 5.4 and 5.8).

[1.15] What happens if I scratch the disc? Aren't discs too fragile to be rented?

Scratches may cause minor data errors that are easily corrected. That is, data is stored on DVDs using powerful error correction techniques that can recover from even large scratches with no loss of data. A common misperception is that a scratch will be worse on a DVD than on a CD because of higher storage density and because video is heavily compressed. DVD data density (say that fast ten times!) is physically four times that of CD-ROM, so it's true that a scratch will affect more data. But DVD error correction is at least ten times better than CD-ROM error correction and more than makes up for the density increase. It's also important to realize that MPEG-2 and Dolby Digital compression are partly based on removal or reduction of imperceptible information, so decompression doesn't expand the data as much as might be assumed. Major scratches may cause uncorrectable errors that will produce an I/O error on a computer or show up as a momentary glitch in DVD-Video picture. Paradoxically, sometimes the smallest scratches can cause the worst errors (because of the particular orientation and refraction of the scratch). There are many schemes for concealing errors in MPEG video, which may be used in future players.

See 1.39 for information on care and cleaning of DVDs.

The DVD computer advisory group specifically requested no mandatory caddies or other protective carriers. Consider that laserdiscs, music CDs, and CD-ROMs are likewise subject to scratches, but many video stores and libraries rent them. Major chains such as Blockbuster and West Coast Entertainment rent DVDs in many locations. Most reports of rental disc performance are positive, although if you have problems playing a rental disc, check for scratches.

[1.16] VHS is good enough, why should I care about DVD?

The primary advantages of DVD are video quality, surround sound, and extra features (see 1.2). In addition, DVD will not degrade with age or after many playings like videotape will (which is an advantage for parents with kids who watch Disney videos twice a week!). This is the same thing that makes CDs more collectable than cassette tapes. Did I mention video quality? The better your TV, the bigger the difference in picture quality between VHS and DVD.

If none of this matters to you, then VHS probably is good enough.

[1.17] Is the packaging different from CD?

Manufacturers were worried about customers assuming DVDs would play in their CD player, so they wanted the packaging to be different. Most DVD packages are as wide as a CD jewel box (about 5-5/8") and as tall as a VHS cassette box (about 7-3/8"), as recommended by the Video Software Dealers Association (VSDA). However, no one is being forced to use a larger package size. Some companies use standard jewel cases or paper and vinyl sleeves. Divx discs came in paperboard and plastic Q-Pack cases the same size as a CD jewel case.

Most movies are packaged in the Amaray "keep case," an all-plastic clamshell with clear vinyl pockets for inserts, that's popular among consumers. Time Warner's "snapper," a paperboard case with a plastic lip, is less popular. There's also a "super jewel box," the stretch-limo version of a CD jewel case, that's common in Europe. 

[1.18] What's a dual-layer disc? Will it work in all players?

A dual-layer disc has two layers of data, one of them semi-transparent so that the laser can focus through it and read the second layer. Since both layers are read from the same side, a dual-layer disc can hold almost twice as much as a single-layer disc, typically 4 hours of video (see 3.3 for more details). Many discs use dual layers. Initially only a few replication plants could make dual-layer discs, but most plants now have the capability. The second layer can use either a PTP (parallel track path) layout where both tracks run in parallel (for independent data or special switching effects), or an OTP (opposite track path) layout where the second track runs in an opposite spiral; that is, the pickup head reads out from the center on the first track then in from the outside on the second track. The OTP layout, also called RSDL (reverse-spiral dual layer), is designed to provide continuous video across both layers. When the laser pickup head reaches the end of the first layer it changes focus to the second layer and starts moving back toward the center of the disc. The layer change can occur anywhere in the video; it doesn't have to be at a chapter point. There's no guarantee that the switch between layers will be seamless. The layer change is invisible on some players, but it can cause the video to freeze for a fraction of a second or as long as 4 seconds on other players. The "seamlessness" depends as much on the way the disc is prepared as on the design of the player. The advantage of two layers is that long movies can use higher data rates for better quality than with a single layer. See 1.27 for more about layer changes.

There are various ways to recognize dual-layer discs: 1) the gold color, 2) a menu on the disc for selecting the widescreen or fullscreen version, 3) two serial numbers on one side.

The DVD specification requires that players and drives read dual-layer discs. There are very few units that have problems with dual-layer discs--this is a design flaw and should be corrected for free by the manufacturer. Some discs are designed with a "seamless layer change" that technically goes beyond what the DVD spec allows. This causes problems on a few older players.

All players and drives also play double-sided discs if you flip them over. No manufacturer has announced a model that will play both sides, other than a few DVD jukeboxes. The added cost would be hard to justify since discs can hold over 4 hours of video on one side by using two layers. (Early discs used two sides because dual-layer production was not widely supported. This is no longer a problem.) Pioneer LD/DVD players can play both sides of a laserdisc, but not a DVD. (See 2.12 for note on reading both sides simultaneously.)

[1.19] Is DVD-Video a worldwide standard? Does it work with NTSC, PAL, and SECAM?

Video on a DVD is stored in digital format, but it's formatted for one of two mutually incompatible television systems: 525/60 (NTSC) or 625/50 (PAL/SECAM). Therefore, there are two kinds of DVDs: "NTSC DVDs" and "PAL DVDs." Some players only play NTSC discs, others play PAL and NTSC discs. Discs are also coded for different regions of the world (see 1.10). NTSC is the TV format used in Canada, Japan, Mexico, Philippines, Taiwan, United States, and other countries. PAL is the TV format used in most of Europe, most of Africa, China, India, Australia, New Zealand, Israel, North Korea, and other countries. (See the chart at www.remoteviewing.com for a complete list.)

Almost all DVD players sold in PAL countries play both kinds of discs. These multi-standard players partially convert NTSC to a 60-Hz PAL (4.43 NTSC) signal. The player uses the PAL 4.43-MHz color subcarrier encoding format but keeps the 525/60 NTSC scanning rate. Most modern PAL TVs can handle this "pseudo-PAL" signal. A few multi-standard PAL players output true 3.58 NTSC from NTSC discs, which requires an NTSC TV or a multi-standard TV. Some players have a switch to choose 60-Hz PAL or true NTSC output when playing NTSC discs. There are a few standards-converting PAL players that convert from an NTSC disc to standard PAL output for older PAL TVs. Proper "on the fly" standards conversion requires expensive hardware to handle scaling, temporal conversion, and object motion analysis. Because the quality of conversion in DVD players is poor, using 60-Hz PAL output with a compatible TV provides a better picture than converting from NTSC to PAL. (Sound is not affected by video conversion.)

Most NTSC players can't play PAL discs, and most NTSC TVs don't work with PAL video. A very small number of NTSC players (such as Apex and SMC) can convert PAL to NTSC. External converter boxes are also available, such as the Emerson EVC1595 (). High-quality converters are available from companies such as TenLab and Snell and Wilcox.

Beware, some standards-converting players can't convert anamorphic widescreen video for 4:3 displays (see 1.22).

The latest software tools such as Adobe After Effects and Canopus ProCoder do quite a good job of converting between PAL and NTSC at low cost, but they are only appropriate for the production environment (converting the video before it is encoded and put on the DVD). See Snell and Wilcox's The Engineer's Guide to Standards Conversion and The Engineer's Guide to Motion Compensation for technical details of conversion.

There are three differences between discs intended for playback on different TV systems: picture dimensions and pixel aspect ratio (720x480 vs. 720x576), display frame rate (29.97 vs. 25), and surround audio options (Dolby Digital vs. MPEG audio). (See 3.4 and 3.6 for details.) Video from film is usually encoded at 24 frames/sec but is preformatted for one of the two required display rates. Movies formatted for PAL display are usually sped up by 4% at playback, so the audio must be adjusted accordingly before being encoded. All PAL DVD players can play Dolby Digital audio tracks, but not all NTSC players can play MPEG audio tracks. PAL and SECAM share the same scanning format, so discs are the same for both systems. The only difference is that SECAM players output the color signal in the format required by SECAM TVs. Note that modern TVs in most SECAM countries can also read PAL signals, so you can use a player that only has PAL output. The only case in which you need a player with SECAM output is for older SECAM-only TVs (and you'll probably need a SECAM RF connection, see 3.1).

A producer can choose to put 525/60 NTSC video on one side of the disc and 625/50 PAL on the other. Most studios put Dolby Digital audio tracks on their PAL discs instead of MPEG audio tracks.

Because of PAL's higher resolution, the video usually takes more space on the disc than the NTSC version. See 3.4 for more details.

There are actually three types of DVD players if you count computers. Most DVD PC software and hardware can play both NTSC and PAL video and both Dolby Digital and MPEG audio. Some PCs can only display the converted video on the computer monitor, but others can output it as a video signal for a TV.

Bottom line: NTSC discs (with Dolby Digital audio) play on over 95% of DVD systems worldwide. PAL discs play on very few players outside of PAL countries. (This is irrespective of regions -- see 1.10.)

[1.20] What about animation on DVD? Doesn't it compress poorly?

Some people claim that animation, especially hand-drawn cell animation such as cartoons and anime, does not compress well with MPEG-2 or even ends up larger than the original. Other people claim that animation is simple so it compresses better. Neither is true.

Supposedly the "jitter" between frames caused by differences in the drawings or in their alignment causes problems. An animation expert at Disney pointed out that this doesn't happen with modern animation techniques. And even if it did, the motion estimation feature of MPEG-2 would compensate for it.

Because of the way MPEG-2 breaks a picture into blocks and transforms them into frequency information it can have a problem with the sharp edges common in animation. This loss of high-frequency information can show up as "ringing" or blurry spots along edges (called the Gibbs effect). However, at the data rates commonly used for DVD this problem does not usually occur.

[1.21] Why do some discs require side flipping? Can't DVDs hold four hours per side?

Even though DVD's dual-layer technology (see 3.3) allows over four hours of continuous playback from a single side, some movies are split over two sides of a disc, requiring that the disc be flipped partway through. Most "flipper" discs exist because of producers who are too lazy to optimize the compression or make a dual-layer disc. Better picture quality is a cheap excuse for increasing the data rate; in many cases the video will look better if carefully encoded at a lower bit rate. Lack of dual-layer production capability is also a lame excuse; in 1997 very few DVD plants could make dual-layer discs, but this is no longer the case. Very few players can automatically switch sides, but it's not needed since most movies less than 4 hours long can easily fit on one dual-layer (RSDL) side.

The Film Vault at DVD Review includes a list of "flipper" discs. Note: A flipper is not the same as a disc with a widescreen version on one side and a pan & scan version or supplements on the other.

[1.22] Why is the picture squished, making things look too skinny?

Answer: RTFM. You are watching an anamorphic picture intended for display only on a widescreen TV. (See 3.5 for technical details). You need to go into the player's setup menu and tell it you have a standard 4:3 TV, not a widescreen 16:9 TV. It will then automatically letterbox the picture so you can see the full width at the proper proportions.

In some cases you can change the aspect ratio as the disc is playing (by pressing the "aspect" button on the remote control). On most players you have to stop the disc before you can change aspect. Some discs are labeled with widescreen on one side and standard on the other. In order to watch the fullscreen version you must flip the disc over.

See 1.38 for more on letterboxing.

Apparently most players that convert from NTSC to PAL or vice-versa (see 1.19) can't simultaneously letterbox (or pan and scan) an anamorphic picture. Solutions are to use a widescreen TV, a multistandard TV, or an external converter. Or get a better player.

[1.23] Do all videos use Dolby Digital (AC-3)? Do they all have 5.1 channels?

Most DVD-Video discs contain Dolby Digital soundtracks. However, it's not required. Some discs, especially those containing only audio, have PCM tracks. It's possible --but rare-- for a 625/50 (PAL) disc to contain only MPEG audio. Discs with DTS audio are required to also include a Dolby Digital audio track (in a few rare cases they have a PCM track). See 1.32 for more on DTS.

Don't assume that the Dolby Digital label is a guarantee of 5.1 channels. A Dolby Digital soundtrack can be mono, dual mono, stereo, Dolby Surround stereo, etc. For example, Blazing Saddles and Caddyshack have monophonic soundtracks, so the Dolby Digital soundtrack on these DVDs has only one channel. Some DVD packaging has small lettering or icons under the Dolby Digital logo that indicates the channel configuration. In some cases, there is more than one Dolby Digital version of a soundtrack: a 5.1-channel track and a track specially remixed for stereo Dolby Surround. It's perfectly normal for your DVD player to indicate playback of a Dolby Digital audio track while your receiver indicates Dolby Surround. This means the disc contains a two-channel Dolby Surround signal encoded in Dolby Digital format.

See 3.6 for more audio details.

[1.24] Can DVDs have "laser rot"?

Before DVDs there were laserdiscs (see 2.6), which were occasionally subject to what was commonly called laser rot: the deterioration of the aluminum layer due to oxidation or other chemical change. This usually results from the use of insufficiently pure metal for the reflective coating created during replication, but can be exacerbated by mechanical shear stress due to bending, warping or thermal cycles (the large size of laserdiscs makes them flexible, so that movement along the bond between layers can break the seal -- this is called delamination). Deterioration of the data layer can be caused by chemical contaminants or gases in the glue, or by moisture that penetrates the plastic substrate.

Like laserdiscs, DVDs are made of two platters glued together, but DVDs are more rigid and use newer adhesives. DVDs are molded from polycarbonate, which absorbs about ten times less moisture than the slightly hygroscopic acrylic (PMMA) used for laserdiscs.

DVDs can have delamination problems, partly because some cases or players hold too tightly to the hub. Delamination by itself can cause problems (because the data layer is no longer at the correct distance from the surface) and can also lead to oxidation. Delamination may appear as concentric rings or a "stain" around the hub.

So far DVDs have had few "DVD rot" problems. There have been reports of a few discs going bad, possibly due to delamination, contaminated adhesive, chemical reactions, or oxidation of the reflective layer (see mindspring.com/~yerington/ and www.andraste.org/discfault/discfault.htm). The most likely explanation for DVD deterioration is that during the early days of DVD (1997-2000), disc manufacturing processes and materials were not as good as they should have been. Many improvements have been made since then, so the minuscule problem has probably become even more minuscule. 

There are also occasional reports of "cloudiness" or "milkiness" in DVDs, which can be caused by improper replication. An example is when the molten plastic cools off too fast or isn't under enough pressure to completely fill all the bumps in the mold (see this archived article from TapeDisc Business  for more). Minimal clouding doesn't hurt playback and doesn't seem to deteriorate. If you can see something with your naked eye it is probably not oxidation or other deterioration.

The result of deterioration is that a disc which played perfectly when it was new develops problems later, such as skipping, freezing, or picture breakup. If a disc seems to go bad, make sure it's not dirty, scratched, or warped (see 1.39). Try cleaning it and try playing it in other players. If the disc consistently has problems, it may have deteriorated. If so, there's nothing you can do to fix it, so you should try to get a replacement from the supplier.

[1.25] Which titles are pan & scan only? Why?

Some titles are available only in pan & scan because there was no letterbox or anamorphic transfer made from film. (See 3.5 for more info on pan & scan and anamorphic formats.) Since transfers cost ,000 to ,000, studios may not think a new transfer is justified. In some cases the original film or rights to it are no longer available for a new transfer. In the case of old movies, they were shot full frame in the 1.37 "academy" aspect ratio so no widescreen version can be created. Video shot with TV cameras, such as music concerts, is already in 4:3 format.

There is a list of pan & scan titles in the Film Vault at DVD Review and in the Internet Movie Database (which also includes discs with both widescreen and pan & scan versions).

[1.26] How do I make the subtitles on my Pioneer player go away?

On the remote control, press Subtitle, then either Clear or 0 (zero). No need to use the menus.

[1.27] Why does playback sometimes freeze for a second?

Some movies, especially those over two hours long or encoded at a high data rate, are spread across two layers on one side of the disc. When the player changes to the second layer, the video and audio may freeze for a moment as the laser refocuses and finds its place. The length of the pause depends on the player and on the layout of the disc. The disc producer usually tries to choose a point where the pause will be less noticeable. The pause is not a defect in the player or the disc. See 1.18 for more information.

There is a list of layer switch points in the Film Vault at DVD Review. Please send new times to info@dvdreview.com.

[1.28] The disc says Dolby Digital. Why do I get 2-channel surround audio?

Some discs (many from Columbia TriStar) have 2-channel Dolby Surround audio (or plain stereo) on track one and 5.1-channel audio on track two. Some studios create separate sound mixes optimized for Dolby Surround or stereo, and they feel the default track should match the majority of sound systems in use. Unless you specifically select the 5.1-channel track (with the audio button on the remote or with the on-screen menu) the player will play the default 2-channel track. (Some players have a feature to automatically select the first 5.1 track.)

Dolby Digital doesn't necessarily mean 5.1 channels. See 1.23 and 3.6.

[1.29] Why doesn't the repeat A-B feature work on some discs?

Almost all features of DVD such as search, pause, and scan can be disabled by the disc, which can prevent the player from searching back to the beginning of a segment. If the player uses time search to repeat a segment, then a disc with fancy non-sequential title organization will not have timecode information the player needs to search. In many cases the authors don't even realize they have prevented the use of the repeat feature.

[1.30] What's the difference between first, second, and third generation DVD?

There is no meaningful answer to this question, since you'll get a different response from everyone you ask. The terms "2nd generation" and "3rd generation," and so on refer both to DVD-Video players and to DVD-ROM drives. In general, they simply mean newer versions of DVD playback devices. The terms haven't been used (yet) to refer to DVD products 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 HD players (see 2.12) that won't come out until 2003 or so. Many conflicting variations occur between these extremes, including the viewpoint that DTS-compatible players or Divx players or progressive-scan players or 10-bit video players or players that can play The Matrix constitute the second, third, or fourth 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. Some people refer to RPC2 drives or 10x drives as fourth generation. See section 4.2 for more speed info. See section 1.10 for an RPC2 explanation.

[1.31] What's a hybrid DVD?

Do you really want the answer to this one? Ok, you asked for it...

  1. A disc that works in both DVD-Video players and DVD-ROM PCs. (More accurately called an enhanced DVD)
  2. A DVD-ROM disc that runs on Windows and Mac OS computers. (More accurately called a cross-platform DVD.)
  3. A DVD-ROM or DVD-Video disc that also contains Web content for connecting to the Internet. (More accurately called a WebDVD or Enhanced DVD.)
  4. A disc that contains both DVD-Video and DVD-Audio content or SACD content. (More accurately called a universal or AV DVD. The DVD-Audio standard allows this. The SACD standard does not officially allow video, so it's unclear what a  given SACD player will do with a hybrid SACD+DVD-Video disc.) Other variations of this hybrid would be a disc with both DVD-Audio and SACD content, or a disc with all three formats.
  5. A disc with two layers, one that can be read in DVD players and one that can be read in CD players. (More accurately called a legacy or CD-compatible disc.) There are at least three variations of this hybrid, although most aren't commercially available:
    1. A 0.9- to 1.2-mm CD substrate bonded to the back of a 0.6 mm DVD substrate. One side can be read by CD players, the other side by DVD players. The resulting disc is 0.6 mm thicker than a standard CD or DVD, which can cause problems in players with tight tolerances, such as portables. Sonopress, the first company to announce this type, calls it DVDPlus. It's colloquially known as a fat disc. There's a variation in which an 8-cm data area is embedded in a 12-cm substrate so that a label can be printed on the outer ring.
    2. A 0.6-mm CD substrate bonded to a semitransparent 0.6 mm DVD substrate. Both layers are read from the same side, with the CD player being required to read through the semitransparent DVD layer, causing problems with some CD players. The trick is to make the semitransparent layer "invisible" to 780-nm CD lasers. This is the format used for hybrid SACDs.
    3. A 0.6-mm CD substrate, with a special refractive coating that causes a 1.2 mm focal depth, bonded to the back of a 0.6 mm DVD substrate. One side can be read by CD players, the other side by DVD players.
    4. A 0.6-mm DVD substrate bonded to a CD+DVD hybrid substrate (#2 in this subsection). This disc would be readable by SACD and CD players on one side and by standard DVD players on the other (since most standard DVD players are confused by a hybrid disc with only a semitransparent layer).
  6. A disc with two layers or two sections one containing pressed (DVD-ROM) data and one containing rewritable (DVD-RAM or other) media for recording. (More accurately called a DVD-PROM,  mixed-media, or rewritable sandwich disc.)
  7. A disc with two layers on one side and one layer on the other. (More accurately called a DVD-14.)
  8. A disc with an embedded memory chip for storing custom usage data and access codes. (More accurately called a chipped DVD.)
  9. A disc that has a foreign language dubbed audio track and also has subtitles in that language.

Did I miss any?

[1.32] What's the deal with DTS and DVD?

Digital Theater Systems Digital Surround is an audio encoding format similar to Dolby Digital. It requires a decoder, either in the player or in an external receiver. See 3.6.2 for technical details. Some people claim that, because of its lower compression level, DTS sounds better than Dolby Digital. Others claim there is no meaningfully perceptible difference, especially at the typical data rate of 768 kbps, which is 60% more than Dolby Digital. Because of the many variances in production, mixing, decoding, and reference levels, it's almost impossible to accurately compare the two formats (DTS usually produces a higher volume level, causing it to sound better in casual comparisons).

DTS originally did all encoding in house, but as of October 1999 DTS encoders became available for purchase. DTS titles are often considered to be specialty items intended for audio enthusiasts, so some DTS titles are also available in a Dolby Digital-only version.

DTS is an optional format on DVD. Contrary to uninformed claims, the DVD specification has included an ID code for DTS since 1996 (before the spec was even finalized). Because DTS was slow in releasing encoders and test discs, players made before mid 1998 (and many since) ignore DTS tracks. A few demo discs were created in 1997 by embedding DTS data into a PCM track (the same technique used with CDs and laserdiscs), and these are the only DTS DVD discs that work on all players. New DTS-compatible players arrived in mid 1998, but theatrical DTS discs using the DTS audio stream ID did not appear until January 7, 1999 (they were originally scheduled to arrive in time for Christmas 1997). Mulan, a direct-to-video animation (not the Disney movie) with DTS soundtrack appeared in November 1998. DTS-compatible players carry an official "DTS Digital Out" logo.

Dolby Digital or PCM audio is required on 525/60 (NTSC) discs, and since both PCM and DTS together don't usually leave enough room for quality video encoding of a full-length movie, essentially every disc with a DTS soundtrack also carries a Dolby Digital soundtrack. This means that all DTS discs will work in all DVD players, but a DTS-compatible player and a DTS decoder are required to play the DTS soundtrack. DTS audio CDs work on all DVD players, because the DTS data is encapsulated into standard PCM tracks that are passed untouched to the digital audio output. DTS discs often carry a Dolby Digital 2.0 track in Dolby Surround format instead of a full Dolby Digital 5.1 track.

[1.33] Why is the picture black and white or or tinted one color?

You may have connected one of the component outputs (usually colored red, green, and blue) of your DVD player to the composite input of your TV. Connect yellow to yellow. See section 3.2 for hookup details. Also, if you've hooked up component video, check the three cables to make sure one of them hasn't become disconnected or developed a short and that they are connected in the correct order.

If you live in a PAL country (most countries outside of the U.S., Canada, and Japan) you may be playing an NTSC disc in a PAL player, but your PAL TV can't handle the signal. If your player has a switch or on-screen setting to select the output format for NTSC discs, choosing PAL (60 Hz) should solve the problem. See section 1.19 for more information.

[1.34] Why are both sides fullscreen when one side is supposed to be widescreen?

Many DVD's are labeled as having widescreen (16:9) format video on one side and standard (4:3) on the other. If you think both sides are the same, you're probably seeing uncompressed 16:9 on the widescreen side. It may look like 4:3 full-frame, but if you look carefully you'll discover that the picture is horizontally compressed. The problem is that your player has been set for a widescreen TV. See 1.22 for details.

[1.35] Why are the audio and video out of sync?

There have been numerous reports of "lip sync" problems, where the audio lags slightly behind the video or sometimes precedes the video. Perception of a sync problem is highly subjective; some people are bothered by it while others can't discern it. Problems have been reported on a variety of players (notably the Pioneer 414 and 717 models, possibly all Pioneer models, some Sony models including the 500 series and the PS2, some Toshiba models including the 3109, and some PC decoder cards). Certain discs are also more problematic (notably Lock, Stock, and Two Smoking Barrels; Lost In Space; TRON; The Parent Trap; and Austin Powers).

The cause of the sync problem is a complex interaction of as many as four factors

  1. Improper sync in audio/video encoding or DVD-Video formatting.
  2. Poor sync during film production or editing (especially post-dubbing or looping).
  3. Loose sync tolerances in the player.
  4. Delay in the external decoder/receiver.

Factor 1 or 2 usually must be present in order for factor 3 or 4 to become apparent. Some discs with severe sync problems have been reissued after being re-encoded to fix the problem. In some cases, the sync problem in players can be fixed by pausing or stopping playback and then restarting, or by turning the player off, waiting a few seconds, then turning it back on.

A good way to test your player is to simultaneously listen to the analog and digital outputs (play the digital output through your stereo and the analog output through your TV). If the audio echoes or sounds hollow, then the player is delaying the signal and is thus the main cause of the sync problem.

Unfortunately, there is no simple answer and no simple fix. More complaints from customers should motivate manufacturers to take the problem more seriously and correct it in future players or with firmware upgrades. Pioneer originally stated that altering the audio-visual synchronization of their players "to compensate for the software quality would dramatically compromise the picture performance." Since then Pioneer has fixed the problem on its new players. If you have an older model, check with Pioneer about an upgrade.

For many more details, see Michael D's Pioneer Audio Sync page.

[1.36] Why does the picture alternate between light and dark?

You are seeing the effects of Macrovision copy protection (see 1.11), probably because you are running your DVD player through your VCR or VCR/TV combo (see 3.2.1).

[1.37] How do I find "Easter eggs" and other hidden features?

Some DVD movies contain hidden features, often called Easter eggs. These are extra screens or video clips hidden in the disc by the developers. For example, Dark City includes scenes from Lost in Space and the Twin Peaks movie buried in the biography pages of William Hurt and Keifer Sutherland. There's also an amusing "Shell Beach" game entwined throughout the menus. On Mallrats, perhaps indicating that DVD has already become too postmodern for its own good, there's a hidden clip of the director telling you to stop looking for Easter eggs and do something useful.

It's more fun to search for hidden features on your own, but if you need some help, the best list is at DVD Review.

[1.38] How do I get rid of the black bars at the top and bottom?

The black bars are part of the letterbox process (see 3.5), and in many cases you can't get rid of them, even if you have a widescreen TV. If you set the display option in your player to pan & scan (sometimes called fullscreen or 4:3) instead of letterbox, it won't do you much good since almost no DVD movies have been released with this feature enabled. If you set the player to 16:9 widescreen output it will make the bars smaller, but this is intended for use with widescreen TVs only — you will get a tall, stretched picture on a standard TV.

In some cases, there may be both a fullscreen and a letterbox version of the movie on the same disc, with a variety of ways to get to the fullscreen version (usually only one works, so you may have to try all three):

  1. Check the other side of the disc (if it's two-sided)
  2. Look for a fullscreen choice in the main menu
  3. Use the "aspect" button on the remote control

DVD was designed to make movies look as good as possible on TV. Since most movies are wider than standard TVs, letterboxing preserves the format of the theatrical presentation. (Nobody seems to complain that the top and bottom of the picture are cut off in theaters.) DVD is ready for TVs of the future, which are widescreen. For these and other reasons, many movies on DVD are only available in widescreen format.

About two thirds of widescreen movies are filmed at 1.85 (flat) aspect ratio or less. In this case, the actual size of the image on your TV is the same for a letterbox version and a full-screen version, unless the pan & scan technique is used to zoom in (which cuts off part of the picture). In other words, the picture is the same size, with extra areas visible at the top and bottom in the fullscreen version. In more other words, letterboxing covers over the part of the picture that was also covered in the theater, or it allows the entire widescreen picture to be visible for movies wider than 1.85, in which case the letterboxed picture is smaller and has less detail than a pan & scan version would.

If you have a widescreen TV, make sure your player is set to 16:9 widescreen output. Most widescreen movies will fill the screen, but some movies are filmed at an aspect ratio of around 2.4. These movies are usually letterboxed to fit the 1.78 aspect ratio of your TV, so there's nothing you can do about the black bars. Just be happy they're much thinner than they would be on a standard TV.

If there's not a fullscreen version of the movie on the disc, one solution is to use a DVD player with a zoom feature to enlarge the picture enough to fill the screen. This will cut off the sides of the picture, but in many cases it's a similar effect to the pan and scan process. Just think of it as "do-it-yourself pan and scan."

For a detailed explanation of why most movie fans prefer letterboxing, see the Letterbox/Widescreen Advocacy Page. For an explanation of anamorphic widescreen and links to more information and examples on other Web sites, see 3.5.

The best solution to this entire mess might be the FlikFX Digital Recomposition System, "the greatest advance in entertainment in 57 years."

[1.39] How should I clean and care for DVDs?

Since DVDs are read by a laser, they are resistant to fingerprints, dust, smudges, and scratches (see 1.15 for more info). 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 globs of nasty substances on it actually hit the lens. Still, it's best to keep your discs clean, which will also keep the inside of your player clean. Don't attempt to play a cracked disc, as it could shatter and damage the player. It doesn't hurt to leave the disc in the player, even if it's paused and still spinning, but leaving it running unattended for days on end might not be a good idea.

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 use a lens cleaning disc in your CD player, you may want to do the same with your DVD player. It's advisable to use a cleaning disc specifically designed for DVD players, because there are minor differences in lens positioning between DVD and CD players.

Periodic alignment of the pickup head is not necessary. Sometimes the laser can drift out of alignment, especially after rough handling of the player, but this is not a regular maintenance item.

Care and feeding of DVDs

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. Don't 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 discs 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. The DVD specification recommends that discs be stored at a temperature between -20 to 50 °C (-4 to 122 °F) with less than 15 °C (27 °F) variation per hour, at relative humidity of 5 to 90 percent. Artificial light and indirect sunlight have no effect on replicated DVDs since they are made of polycarbonate, polymer adhesives, and metal (usually aluminum or gold), none of which are significantly affected by exposure to light. Exposure to bright sunlight may affect recordable DVDs, specifically write-once DVDs (DVD-R and DVD+R) that use light-sensitive dyes. Magnetic fields have no effect on DVDs, so it's ok to leave them sitting on your speakers.

Coloring the outside edge of a DVD with a green marker (or any other color) makes no difference in video or audio quality. Data is read based on pit interference at 1/4 of the laser wavelength, a distance of 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.

NIST has prepared a 1-page guide and a 50-page guide to disc care.

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. CD cleaning products work as well as DVD cleaning products.

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 error correction (ECC) block. Examine the disc to find scratches, keeping in mind that the laser reads from the bottom. There are essentially two methods of repairing scratches: 1) fill or coat the scratch with an optical material; 2) polish down the scratch. There are many commercial products that do one or both of these, or you may wish to do it yourself with polishing compounds or toothpaste. The trick is to polish out the scratch without causing new ones. A mess of small polishing scratches may cause more damage than a big scratch. As with cleaning, polish only in the radial direction.

Libraries, rental shops, and other venues that need to clean a lot of discs may wish to invest in a commercial polishing machine that can restore a disc to pristine condition after an amazing amount of abuse. Keep in mind that the data layer on a DVD is only half as deep as on a CD, so a DVD can only be repolished about half as many times.

[1.40] What's a progressive DVD player?

A progressive-scan DVD player converts the interlaced (480i or 576i) video from DVD into progressive (480p or 576p) format for connection to a progressive-scan display (31.5 kHz or higher). Progressive players work with all standard DVD titles, but look best with film source. The result is a significant increase in perceived vertical resolution for a more detailed and film-like picture. Since computers use progressive-scan monitors, DVD PCs are by definition progressive-scan players, although quality varies quite a bit (see 4.1 and 2.12).

There's enormous confusion about whether DVD video is progressive or interlaced. Here's the one true answer: Progressive-source video (such as from film) is usually encoded on DVD as interlaced field pairs that can be reinterleaved by a progressive player to recreate the original progressive video. See 3.8 for further explanation of interlaced and progressive scanning.

You must use a progressive-scan display in order to get the full benefit of a progressive-scan player. However, all progressive players also include interlaced outputs, so you can use one with a standard TV until you upgrade to a progressive TV. (You may have to use a switch on the back of the player to set it to interlaced output.)

Toshiba developed the first progressive-scan player (SD5109, ) in mid 1998, but didn't release it until fall of 1999 because of copy protection concerns. Panasonic also released a progressive-scan player (DVD-H1000, ) in fall of 1999. Many manufacturers have released progressive models since then at progressively cheaper prices (pun intended). It's also possible to buy an external line multiplier to convert the output of a standard DVD player to progressive scanning.

Converting interlaced DVD video to progressive video involves much more than putting film frames back together. There are essentially three ways to convert from interlaced to progressive:
1- reinterleaving (also called weave). If the original video is from a progressive source, such as film, the two fields can be recombined into a single frame.
2- Line doubling (also called bob). If the original video is from an interlaced source, simply combining two fields will cause motion artifacts (the effect is reminiscent of a zipper), so each line of a single field is repeated twice to form a frame. Better line doublers use interpolation to produce new lines that are a combination of the lines above and below. The term line doubler is vague, since cheap line doublers only bob, while expensive line doublers (those that contain digital signal processors) can also weave.
3- Field-adaptive deinterlacing, which examines individual pixels across three or more fields and selectively weaves or bobs regions of the picture as appropriate. Chips to do this used to cost ,000 and up, but the feature is now appearing in consumer DVD players.
4- And there's also a fourth way, called motion-adaptive deinterlacing, which examines MPEG-2 motion vectors or does massive image processing to identify moving objects in order to selectively weave or bob regions of the picture as appropriate. Most systems that do this well cost ,000 and up (aside from the cool but defunct Chromatic Mpact2 chip).

There are three common kinds of deinterlacing systems:
1- Integrated. This is usually best, where the deinterlacer is integrated with the MPEG-2 decoder so that it can read MPEG-2 flags and analyze the encoded video to determine when to bob and when to weave. Most DVD computers use this method.
2- Internal. The digital video from the MPEG-2 decoder is passed to a separate deinterlacing chip. The disadvantage is that MPEG-2 flags and motion vectors may no longer available to help the deinterlacer determine the original format and cadence. (Some internal chips receive the repeat_first_field and top_field_first flags passed from the decoder, but not the progressive_scan flag.)
3- External. Analog video from the DVD player is passed to a separate deinterlacer (line multiplier) or to a display with a built-in deinterlacer. In this case, the video quality is slightly degraded from being converted to analog, back to digital, and often back again to analog. However, for high-end projection systems, a separate line multiplier (which scales the video and interpolates to a variety of scanning rates) may achieve the best results.

Most progressive DVD players use an internal deinterlacing chip, usually from Genesis/Faroudja. Some use MPEG decoders with integrated deinterlacing. Some, such as Toshiba's "Super Digital Progressive" players and Panasonic's progressive-scan player add 4:4:4 chroma oversampling, which provides a slight quality boost from DVD's native 4:2:0 format. Add-on internal deinterlacers such as the Cinematrix and MSB Progressive Plus are available to convert existing players to progressive-scan output. Faroudja, Silicon Image (DVDO), and Videon (Omega) line multipliers are examples of external deinterlacers.

A progressive DVD player has to determine whether the video should be line-doubled (bobbed) or reinterleaved (weaved). When reinterleaving film-source video, an NTSC DVD player also has to deal with the difference between film frame rate (24 Hz) and TV frame rate (30 Hz). Since the 2-3 pulldown trick can't be used to spread film frames across video fields, there are worse motion artifacts than with interleaved video. However, the increase in resolvable detail more than makes up for it. Advanced progressive players such as the Princeton PVD-5000 and DVD computers can get around the problem by displaying at multiples of 24 Hz such as 72 Hz, 96 Hz, and so on.

A progressive player also has to deal with problems such as video that doesn't have clean cadence (as when it's edited after being converted to interlaced video, when bad fields are removed during encoding, when the video is speed-shifted to match the audio track, and so on). Another problem is that many DVDs are encoded with incorrect MPEG-2 flags, so the reinterleaver has to recognize and deal with pathological cases. In some instances it's practically impossible to determine if a sequence is 30-frame interlaced video or 30-frame progressive video. For example, the documentary on Apollo 13 is interlaced video encoded as if it were progressive. Other examples of improper encoding are Titanic, Austin Powers, Fargo, More Tales of the City, the Galaxy Quest theatrical trailer, and The Big Lebowski making-of featurette.

One problem is that many TVs with progressive input don't allow the aspect ratio to be changed -- they assume all progressive-scan input is anamorphic. When a non-anamorphic (4:3) picture is sent to these TVs they distort it by stretching it out! Before you buy a DTV, make sure that it allows aspect ratio adjustment on progressive input. Or get a player with an aspect ratio control option that "windowboxes" 4:3 video into a 16:9 rectangle by squeezing it horizontally and adding black bars on the side. Because of the added scaling step this degrades picture quality, but at least it gets around the problem.

Just as early DVD computers did a poor job of progressive-scan display of DVDs, the first generations of progressive consumer players are also a bit disappointing. But as techniques improve, and as DVD producers become more aware of the steps they must take to ensure good progressive display, and as more progressive displays appear in homes, the experience will undoubtedly improve, bringing home theaters closer to real theaters.

For more on progressive video and DVD, see part 5 and player ratings in the excellent DVD Benchmark series at Secrets of Home Theater and High Fidelity.

[1.41] Why doesn't disc X work in player Y?

The DVD specification is complex and open to interpretation. DVD-Video title authoring is also very complex. As with any new technology, there are compatibility problems. The DVD-Video standard has not changed substantially since it was finalized in 1996, but many players don't properly support it. Discs have become more complex as authoring tools improve, so recent discs often uncover engineering flaws in players. Some discs behave strangely or won't play at all in certain players. In some cases, manufacturers can fix the problem with an upgrade to the player (see 1.47). In other cases, disc producers need to reauthor the title to correct an authoring problem or to work around a player defect. Problems can also occur because of damaged or defective discs or because of a defective player.

If you have problems playing a disc, try the following:

  1. Check the list below to see if it's a reported problem. Also check the list of problem discs in DVD Review's Film Vault and at InterActual's tech support page. Try a newsgroup search at Google.
  2. Try playing the disc a few more times. If you don't get the exact same problem every time, then it's probably a defective or damaged disc. Make sure the disc isn't dirty or scratched (see 1.39).
  3. Try the disc in a different player. (Visit a friend or a nearby store that sells players.) If the disc plays properly in a different player then your player is likely at fault. Contact the manufacturer of your player for a firmware upgrade. Or, if you bought the player recently, you may wish to return it for a different model.
  4. Try a different copy of the disc. If the problem doesn't recur, it indicates that your first copy was probably damaged or defective. If more than one copy of the disc has problems in more than one player, it may be a misauthored disc. Contact the distributor or the studio about getting a corrected disc.
  5. If it's a recordable disc (R/RW), your player might not be able to read it (see 4.3.1).

For other DVD and home theater problems, try Doc DVD or DVD Digest's Tech Support Zone. If you have a Samsung 709, see the Samsung 709 FAQ. For troubleshooting DVD on computers, see 4.6. The Dell Inspiron 7000 DVD Movie List has Inspiron-specific problems.

Below are problems reported by readers of this FAQ. The FAQ author has not verified these claims and takes no responsibility for their accuracy. Please report other confirmed problems. 

Title Player Problem Solution
various Polygram titles early Toshiba and Magnavox models won't load or freezes upgrade available from Toshiba service centers
various Central Park Media (anime) titles similar problems as The Matrix
any all-region title many JVC models rejects disc
RCE titles (see 1.10) Fisher DVDS-1000,  Sanyo Model DVD5100 world map and "only plays on non-modified players" message contact tech Sanyo/Fisher support for workaround
The Abyss, SE early Toshiba models disc 2 won't load or freezes upgrade available from Toshiba service centers
many cheap players  repeats scenes player doesn't properly handle seamless branching, get upgrade from manufacturer
Apex AD-600A scenes play twice check with Apex for upgrade
AI (PAL region 2) Wharfdale 750 won't play  
Akira SE Pioneer DV-37, DV-737, DV-525 freezes in several places fast forward to skip trouble spots
Aliens 20th Anniversary Edition Pioneer DV-S737 picture degrades after layer change  
American Beauty (Awards Edition) Toshiba SD-3108, Philips DVD805 won't load upgrade from manufacturer service center (Toshiba firmware 3.30 or newer)
American Pie Philips 940 freezes at layer change (1:17:09)  
Any Given Sunday Pioneer Elite DVL90 won't load upgrade from Pioneer service center
Arlington Road see Cruel Intentions
Armageddon Panasonic A115-U and A120-U won't load unplug player with disc inserted, plug in, turn on
Avenger's TV series (A&E) Toshiba SD-3108 locks up player upgrade available from Toshiba service centers
Philips 930, 935 won't load check with Philips for firmware upgrade
Back to the Future Trilogy (region 4) various players "anecdote" subpictures don't play properly  
Bats Apex AD 600A wont' load check with Apex for upgrade
Big Trouble in Little China Special Edition Panasonic SC-DK3 won't load unplug player with disc inserted, plug in, turn on
The Blair Witch Project some Toshiba players doesn't play properly upgrade available from Toshiba service centers
Bruce Springsteen: Live in Barcelona various players menu doesn't work or tour documentary doesn't play call Sony Pictures at 800-255-7514 for a new version of the disc
Cheers, Season 2 Apex AD-3201 no audio  
Cruel Intentions some JVC and Yamaha players error in first release messes up parental controls, causing other discs to not play reset the player or get the corrected version of the disc or set parental country code to AD with password of 8888
Deep Blue Sea similar problems as The Matrix
Dinosaur many players (JVC-XV501BK, Philips DVD781 CH, Pioneer DV-737/ DV-37/ DV-09/ DVL-919/ DV-525/ DVL-90/ KV-301C, Sony 7700, Panasonic A300, Toshiba SD-3109, RCA 5220, Denon DVD 2500, Magnavox DVD502AT Toshiba 2109/3109, JVC XV-D2000/XV-D701 Oritron DVD600/DVD100, Sylvania DVL100A, and others) won't load, ejects disc, freezes, skips, slow menus, won't pause/forward/rewind, sound cuts out authoring problem -- contact Disney for a replacement (also see Disney's The Kid below)
Disney's The Kid many players (Apex 600AD, Philips 711, Pioneer DV-737, RCA, and others) skips, ejects disc, freezes, blue lines on screen authoring problem -- contact Disney for a replacement; (solution on Philips player: put disc in drawer, do not close drawer, press "1" on remote to jump to chapter 1)
Dragon's Lair Toshiba SD-2109/3109 (before mid 1999) various upgrade available from Toshiba service centers
most Samsung, Aiwa various check with Samsung (800-726-7864) or Aiwa for firmware upgrade
Enigma-2002 Toshiba SD-4700 won't play  
Entrapment JVC, Sony 850 freezes check with JVC for firmware upgrade
Sigma Hollywood Plus see The World Is Not Enough
Everything, Everything (Underworld) Toshiba SD3108 and SD3109 won't load upgrade available from Toshiba service centers
Evolution Many computer DVD software players won't play contact studio for new version of disc
Finding Nemo Pioneer DV-563AS pixelization in spots (especially Sea Turtle sequence)  
Galaxy Quest most Samsung players freezes at chapter 7 check with Samsung (800-726-7864) for firmware upgrade
Girl, Interrupted Apex AD-600A, Shinco 2120, Smart DVDMP3000, others jumps to Features menu, won't play movie press Resume on remote control; upgrade available for Smart
Gladiator Toshiba SD3108/SD3109, Wharfedale DVD 750, others won't load contact studio for new version of disc
The Godfather Collection, bonus disc A few players various problems upgrade your player or get new disc from Paramount (replacement disc works around player bugs)
Good Will Hunting Apex AD-3201 won't play audio commentary
Idle Hands see Cruel Intentions
In the Heat of the Night Pioneer Elite DVL-90 won't play
In Too Deep Toshiba SD-5109 won't play Dolby Digital audio unless PCM (music video) played first  
Independence Day Toshiba SD3108 and SD3109 won't load upgrade available from Toshiba service centers
Philips DVD805 and DVD855 won't load check for upgrade from Philips
many cheap players  repeats scenes player doesn't properly handle seamless branching, get upgrade from manufacturer
Insomnia Toshiba SD1700 stutters and freezes  
The Last Broadcast GE 1105P won't load  
The Last Of the Mohicans see The World Is Not Enough
The Lord of the Rings: The Two Towers, Extended Edition Aiwa XD-DV370 discs 3 and 4 won't play check with Aiwa
Lord Peter Wimsey: The Nine Taylors Yamaha DVD-C900 disc 2 won't load or freezes in menu  
Lost In Space Sharp freezes  
Creative DXR3 freezes, audio out of sync check for updated drivers
The Man With The Golden Gun a few first-generation players, many software player garbled video after layer change might be a disc authoring error
The Matrix various players various problems details at InterActual tech support
(for GE 1105-P, serial number beginning with 940 or lower, get upgrade from GE; see Samsung 709 FAQ)
Mission Impossible II Toshiba SD-3108 won't load get upgrade from manufacturer service center
Mission to Mars Toshiba SD-3108 won't load get upgrade from manufacturer service center
Monsters Inc. Various players locks up near end of movie seems to be player flaws -- check for player upgrade; Disney may re-author disc with a workaround
The Mummy Philips 930, 935 won't load  
The Mummy Returns Zenith DVD 2200 Video skewed left or right on bonus material
The Patriot Apex AD 600A wont' play movie check with Apex for upgrade (pressing Resume may work)
JVC XV-511BK won't load check with JVC for upgrade 
The Perfect Storm Toshiba SD-3108 won't load get upgrade from manufacturer service center
Planet of the Apes Toshiba SD-2109 PIP feature activates and locks up when the two ape generals fight.  
The Princess Bride Special Edition Toshiba SD-3109 freezes during first sword fight scene
Saving Private Ryan all players distortion (smearing, flares)  in beach scene at end of ch. 4 This is a deliberate camera effect in the film. Stop returning discs.
Scary Movie Creative Encore 12x, GE 1105P crashes in FBI warning try to skip past FBI warning; check for bug fix from Creative
The Simpsons; The Complete Second Season Yamaha DVD-C900 some special features on disc 4 cause player to crash  
The Sixth Sense Sigma Hollywood Plus MMSYSTEM275 error wait for a software update from Sigma
Sleepy Hollow some Toshiba players doesn't play properly upgrade available from Toshiba service centers
Snow White Windows 2000 and Windows XP doesn't play movie fix available from Microsoft
Space Ace see Dragon's Lair
Stargate SE Magnavox 400AT freezes in director's commentary  
Stuart Little see Girl Interrupted
The Three Kings LG DVD-2310P won't play extras  
Thomas the Tank Engine see Girl Interrupted
Tomorrow Never Dies Sharp 600U
Bush DVD2000		 locks up player
won't load		  
Universal Soldier Wharfedale 750 picture breakup after ch. 30 might be a problem with the disc
Wild Wild West Samsung DVD 709; Philips 930, 935; GE 1105P  won't load check with Samsung (800-726-7864), Philips, or GE for firmware upgrade
The World Is Not Enough Sigma Hollywood Plus MMSYSTEM275 error Wait for a software update from Sigma. Might be related to trying to play in wrong region.
The World Is Not Enough (region 2) Philips 750 stutters and freezes presumably a flaw in the player; plays region 1 version ok
You've Got Mail various players various problems details at InterActual tech support

[1.42] How do the parental control and multi-rating features work?

DVD includes parental management features for blocking playback and for providing multiple versions of a movie on a single disc. Players (including software players on PCs) can be set to a specific parental level using the onscreen settings. If a disc with a rating above that level is put in the player, it won't play. In some cases, different programs on the disc have different ratings. The level setting can be protected with a password.

A disc can also be designed so that it plays a different version of the movie depending on the parental level that has been set in the player. By taking advantage of the seamless branching feature of DVD, objectionable scenes are automatically skipped over or replaced during playback. This requires that the disc be carefully authored with alternate scenes and branch points that don't cause interruptions or discontinuities in the soundtrack. There is no standard way to identify which discs have multi-rated content.

Unfortunately, very few multi-rating discs have been produced. Hollywood studios are not convinced that there is a big enough demand to justify the extra work involved (shooting extra footage, recording extra audio, editing new sequences, creating branch points, synchronizing the soundtrack across jumps, submitting new versions for MPAA rating, dealing with players that don't properly implement parental branching, having video store chains refuse to carry discs with unrated content, and much more). If this feature is important to you, let the studios know. A list of studio addresses is available at DVD File, and there's a Studio and Manufacturer Feedback area at Home Theater Forum. You might also want to visit the Viewer Freedom site.

Multi-ratings discs include Kalifornia, Crash, Damage, Embrace of the Vampire, Poison Ivy, Species II. In most cases these discs provide "un-cut" or unrated versions that are more intense than the original theatrical release. Discs that use multi-story branching (not always seamless) for a director's cut or special edition version include Dark Star, Stargate SE, The Abyss, Independence Day, and Terminator 2 SE (2000 release). Also see multipath movies at Brilliant Digital.

Another option is to use a software player on a computer that can read a playlist telling it where to skip scenes or mute the audio. Playlists can be created for the thousands of DVD movies that have been produced without parental control features. ClearPlay seems to be the most successful product of this type. A shareware Cine-bit DVD Player did this, but it has been withdrawn apparently because of legal threats from Nissim, who seem determined to stifle the very market they claim to support. A Canadian company, Select Viewing, is releasing software for customized DVD playback on Windows PCs. A few similar projects are under development.

Yet another option is TVGuardian, a device that attaches between the DVD player and the TV to filter out profanity and vulgar language. The box reads the closed caption text and automatically mutes the audio and provides substitute captions for objectionable words. (Note that current versions of these devices don't work with digital audio connections, and don't work with DVDs without NTSC Closed Captioning.)

[1.43] Which discs include multiple camera angles?

There's a euphemism in the DVD industry, where "multi-angle titles" --spoken with the right inflection-- means adult titles. However, apart from thousands of XXX-rated discs, not very many mainstream DVDs have multiple angles, since it takes extra work and limits playing time (a segment with two angles uses up twice as much space on the disc).

Short Cinema Journal vol. 1 was one of the first to use camera angles, in the animated "Big Story," which is also available on the DVD Demystified first edition sample disc. Ultimate DVD (Gold or Platinum) is another sample disc with examples of angles. King Crimson: Deja Vroom has excellent angles, allowing you to focus on any of the musicians. Other multi-angle music discs include Dave Matthews Band: Listener Supported, Metallica Cunning Stunts, Sarah McLachlan Mirrorball. Some movies, such as Detroit Rock City (KISS video), Ghostbusters SE, Mallrats, Suicide Kings, Terminator 2 SE, and Tomorrow Never Dies SE use multiple angles in supplements. Some discs, especially those from Buena Vista, use the angle feature to show credits in the selected language (usually with the angle key locked out).

You can get an incomplete list of multi-angle discs by doing an extended search at DVD File or other sites with searchable databases (see 1.6).

[1.44] Is it ok to put labels or magnetic strips on DVDs?

Labels and adhesive strips are dangerous because they can unbalance the disc and cause errors, or even damage a player, especially if they peel off while the disc is spinning. Pressure-sensitive adhesives break down over time, so it's possible for labels to come loose after a few years. Libraries and DVD rental outlets often want to label discs or attach magnetic strips for security, but it's best not to use them at all. If you must, use a ring-shaped "donut" label that goes around the center of the disc. As long as the circular label doesn't interfere with the player clamping onto the hub, it should be ok. If you have to use a non-circular sticker, place it as close to the center as possible to minimize unbalancing. Placing a second sticker straight across from the center will also help. Writing with a marker in the clear (not reflective) area at the hub is better than using a sticker, although there's not much room to write. Write only in the area inside a 44-mm diameter. Writing anywhere else on the disc is risky, since the ink could possibly eat away the protective coating and damage the data layer underneath.

In most cases a better alternative for security is a case that can only be opened with special equipment at the register or checkout counter. Barcodes, stickers, and security strips can be placed on the case without endangering discs (or players). This is especially good for double-sided discs, which have no space for stickers.

There are full-size round labels designed to go on recordable CDs and DVDs, but they have been known to cause problems. As DVD-ROM drives get faster and faster, destabilization of the disc by a label may cause read errors. A better (but more expensive) solution is to use an inkjet disc printer (IMT, Odixion, Primera, Rimage, Trace Affex) with printable-surface discs. Some drives have the HP LightScribe feature, where if you have software that supports LightScribe, and you use special LightScribe discs with a photosensitive label side, after you record the disc you can put it back in the drive upside down to "etch" a label on the disc.

If you do use adhesive paper "donut" labels, it's best to get one of the devices that helps you center the label on the disc. Wolrdlabel.com has free templates for printing on CD and DVD adhesive labels.

[1.45] What's the difference between Closed Captions and subtitles?

Closed Captions (CC) are a standardized method of encoding text into an NTSC television signal. The text can be displayed by a TV with a built-in decoder or by a separate decoder. All TVs larger than 13 inches sold in the US since 1993 have Closed Caption decoders. Closed Captions can be carried on DVD, videotape, broadcast TV, cable TV, and so on.

Even though the terms caption and subtitle have similar definitions, captions commonly refer to on-screen text specifically designed for hearing impaired viewers, while subtitles are straight transcriptions or translations of the dialogue. Captions are usually positioned below the person who is speaking, and they include descriptions of sounds (such as gunshots or closing doors) and music. Closed captions are not visible until the viewer activates them. Open captions are always visible, such as subtitles on foreign videotapes.

Closed Captions on DVDs are carried in a special data channel of the MPEG-2 video stream and are automatically sent to the TV. You can't turn them on or off from the DVD player. Subtitles, on the other hand, are DVD subpictures, which are full-screen graphical overlays (see 3.4 for technical details). One of up to 32 subpicture tracks can be turned on to show text or graphics on top of the video. Subpictures can also be used to create captions. To differentiate from NTSC Closed Captions and from subtitles, captions created as subpictures are usually called "captions for the hearing impaired."

If this is all too confusing, just follow this advice: To see Closed Captions, use the CC button on the TV remote. To see subtitles or captions for the hearing impaired, use the subtitle button on the DVD remote or use the onscreen menu provided by the disc. Don't turn both on at once or they'll end up on top of each other. Keep in mind that not all DVDs have Closed Captions or subtitles. Also, some DVD players don't reproduce Closed Captions at all.

See DVD File's A Guide to DVD Subtitles and Captioning, Gary Robson's Caption FAQ, and Joe Clark's DVD Accessibility for more about Closed Captions. Note that DVD does not support PAL Teletext, the much-improved European equivalent of Closed Captions.

[1.46] What do the "D" codes on region 2 DVDs mean?

Some non-U.S. discs from Warner, MGM, and Disney are marked with a distribution zone number. "D1" identifies a UK-only release. These often have English-only soundtracks with BBFC censoring. "D2" and "D3" identify European DVDs that are not sold in the UK and Ireland. These often contain uncut or less cut versions of films. "D4" identifies DVDs that are distributed throughout all of Europe (region 2) and Australia/New Zealand (region 4).

[1.47] What's firmware and why would I need to upgrade it?

DVD players are simple computers. Each one has a software program that controls how it plays discs. Since the software is stored on a chip, it's called firmware. Some players have flaws in their programming that cause problems playing certain DVDs. In order to correct the flaws, or in some cases to work around authoring errors on popular discs, the player must be upgraded with a replacement firmware chip. This usually has to be done in a factory service center, although some players can be upgraded simply by inserting a CD. See 1.41 for more on compatibility problems.

[1.48] Are there discs to help me test, optimize, or show off my audio/video system?

A few DVDs are designed specifically for testing and optimizing video and audio playback. Some also demonstrate special features of DVD:

Here are a few movies that work especially well for demonstrating DVD's video and audio quality:

  • Dinosaur - Direct-to-DVD digital transfer gives sharp, clear images; good bass on footsteps and fights.
  • The Eagles: Hell Freezes Over - Outstanding 5.1-channel music (DTS only, Dolby Digital tracks are 2-channel).
  • The Fifth Element - Excellent video, especially in beginning desert scenes, with stellar audio as well.
  • Gladiator - Stunning surround audio with brilliantly mixed orchestration.
  • O Brother, Where Art Thou - Beautiful color and incredible detail (check out facial stubble) with well-rendered shadows.
  • Terminator 2: Judgment Day (Ultimate Edition) - Great video for shadows and reds; highly dimensional audio.
  • Toy Story 2 - Perfect all-digital transfer results in sharp, rich images; sound effects are nicely staged.
  • U-571 - Intense surround effects. Earthshaking bass makes a great subwoofer demo.

Films on Disc has a list of ISF DVD citations -- examples of the best of the craft.

[1.49] What do Sensormatic and Checkpoint mean?

Sensormatic and Checkpoint are two point-of-sale security systems. The names refer to the little metal tags that are inserted into DVD packaging to set off an alarm if you go through the sensors at the store entrance without having the tags deactivated during checkout. The tags are placed in the packages at the replication plant so that it doesn't have to be done at the store. This is called source tagging.

[1.50] What are Superbit, Infinifilm, and other variations of DVD?

There is one single DVD-Video standard. However, within the DVD-Video format there is a great deal of flexibility in the way discs can be created. Different studios have come up with brand names for their particular implementations of advanced features. There's nothing extraordinary about any particular variation, other than a studio spending a lot of time and effort making it work well and promoting it. These kinds of advanced DVDs should play on most players but may reveal more player bugs than standard discs (see 1.41).

Superbit DVDs, from Columbia TriStar, use a high data rate for the video to improve picture quality. Additional language tracks and other extras are left off the disc to make room for more video data and for a DTS audio track. In most cases the difference is subtle, but it does improve the experience on high-end players and progressive-scan displays. See superbitdvd.com for marketing fluff.

Infinifilm DVDs, from New Line, let you watch a movie with pop-ups that direct you to extra content such as an interview, behind-the-scenes-footage, or historical information. See infinifilm.com for more hype.

[1.51] I don't know the parental control password for my player. What do I do?

Most DVD players allow you to lock out discs above a certain rating (see 1.42). The rating level is protected by a password so that children (or spouses) can't change it. If you don't know the password you won't be able to play some discs. You might be able to clear the password by resetting the player (see the user manual) or unplugging it for a few days. In some cases you might be able to use the default password (0000, 9999, or 3308). Otherwise you'll have to call the customer service number of the manufacturer and see if they can help you. Make sure you speak in a deep voice so they don't think you are a kid trying to hack into his parents' player.

[1.52] Can my DVD player get a virus?

There's almost no chance your DVD player can be infected with a virus of the kind that infect computer software. DVD players have simple computers in them that run commands from the disc as it plays, but memory is reset when you press Stop or eject the disc. The firmware in some DVD players can be upgraded by inserting a special disc (see 1.47), so it's theoretically possible someone could make a disc that damages the firmware of a player, but it's highly unlikely and would only affect a few models.

[1.53] Will x-rays hurt DVDs?

No. X-ray machines such as those used for airport security have no effect on storebought DVDs or on DVDs that you have recorded (R, RW, or RAM format).
 

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