alt.video.dvd Frequently Asked Questions (FAQ)
Jim Taylor
Archive-name: rec-video/dvd-faq
Posting-Frequency: monthly
Last-modified: Mar 8, 1997
URL: http://www.videodiscovery.com/vdyweb/dvd/dvdfaq.html
Maintainer: Jim Taylor <jhta...@videodiscovery.com>
DVD Frequently Asked Questions (with answers!)
This is the 8-Mar-97 revision of the FAQ for the alt.video.dvd Usenet
newsgroup. (See section 7.1 for what's new.)
Please send corrections, additions, and new questions to Jim Taylor
<mailto:jhta...@videodiscovery.com>.
Where can I get this FAQ?
* It is posted periodically as "alt.video.dvd Frequently Asked Questions
(FAQ)" to alt.video.dvd, news.answers, alt.answers, and other relevant
newsgroups.
* The most current version is on the Web at
<http://www.videodiscovery.com/vdyweb/dvd/dvdfaq.html>.
* Archives of the last posting are at
<http://www.landfield.com/faqs/rec-video/dvd-faq>,
<http://rtfm.mit.edu>, and
<ftp://ftp.videodiscovery.com/videodiscovery/dvd/dvdfaq.txt>
Contents
* [1] General DVD
* [1.1] What is DVD?
* [1.2] What are the features of DVD-Video?
* [1.3] What's the quality of DVD-Video? Why do some demos look so
bad?
* [1.4] What are the disadvantages of DVD?
* [1.5] When will DVD players and drives be available?
* [1.6] When will DVD titles be available, and how many?
* [1.7] How much do players and drives cost?
* [1.8] How much do discs cost?
* [1.9] How quickly will DVD become established?
* [1.10] What are "regional codes," "country codes," or "zone
locks"?
* [1.11] What are the copy protection issues?
* [1.12] What about DVD-Audio or Music DVD?
* [1.13] Which studios are supporting DVD? Didn't some studios say
they won't support it?
* [1.14] Will DVD record from VCR/TV/etc?
* [1.15] What happens if I scratch the disc? Aren't discs too
fragile to be rented?
* [1.16] VHS is good enough, why should I care about DVD?
* [1.17] Is the packaging different from CD?
* [1.18] When will double-sided or dual-layer discs appear? Will
they work in all players?
* [1.19] Is DVD-Video a worldwide standard? Does it work with NTSC,
PAL and SECAM?
* [1.20] What about animation on DVD? Doesn't it compress poorly?
* [2] DVD's relationship to other products
* [2.1] Will DVD replace VCRs?
* [2.2] Will DVD replace CD-ROM?
* [2.3] Can CD-R writers create DVDs?
* [2.4] Is CD compatible with DVD?
* [2.4.1] Is CD audio (CD-DA) compatible with DVD?
* [2.4.2] Is CD-ROM compatible with DVD-ROM?
* [2.4.3] Is CD-R compatible with DVD-ROM?
* [2.4.4] Is CD-RW compatible with DVD?
* [2.4.5] Is VideoCD compatible with DVD?
* [2.4.6] Is Photo CD compatible with DVD?
* [2.4.7] Is CD-i compatible with DVD?
* [2.4.8] Is Enhanced CD compatible with DVD?
* [2.4.9] Is CD+G compatible with DVD?
* [2.4.10] Is CDV compatible with DVD?
* [2.5] Is laserdisc compatible with DVD?
* [2.6] Will DVD replace laserdisc? Should I buy laserdisc now or
wait for DVD and HDTV?
* [2.7] How does DVD compare to laserdisc?
* [2.8] Can I modify or upgrade my laserdisc player to play DVD?
* [2.9] Will DVD support HDTV (DTV/ATV)?
* [3] DVD technical details
* [3.1] What are the outputs of a DVD player?
* [3.2] How do I hook up a DVD player?
* [3.3] What are the sizes and capacities of DVD?
* [3.4] What are the video details?
* [3.5] How do the aspect ratios work?
* [3.6] What are the audio details?
* [3.7] How do the interactive features work?
* [4] DVD and computers
* [4.1] Can I play DVD movies on my computer?
* [4.2] What are the features and speeds of DVD-ROM drives?
* [4.3] What about recordable DVD-ROM: DVD-R and DVD-RAM?
* [5] DVD production
* [5.1] How much does it cost to produce a DVD? Isn't DVD much more
expensive than videotape, laserdisc, and CD-ROM?
* [5.2] What DVD authoring systems are available and how much do
they cost?
* [5.3] Who can produce a DVD for me?
* [6] Miscellaneous
* [6.1] Who invented DVD and who owns it?
* [6.2] Who is making or supporting DVD products?
* [6.3] Where can I get more information about DVD?
* [7] Leftovers
* [7.1] What's new in this FAQ?
* [7.2] Remaining unanswered questions
* [7.3] Notation and units
* [7.4] Acknowledgments
----------------------------------------------------------------------------
[1] General DVD
[1.1] What is DVD?
DVD, which stands for Digital Video Disc, Digital Versatile Disc, or
nothing, depending on whom you ask, is the next generation of optical disc
storage technology. It's essentially a bigger, faster CD that can hold video
as well as audio and computer data. DVD aims to encompass home
entertainment, computers, and business information with a single digital
format, eventually replacing audio CD, videotape, laserdisc, CD-ROM, and
perhaps even video game cartridges. DVD has widespread support from all
major electronics companies, all major computer hardware companies, and most
major movie and music studios, which is unprecedented and says much for its
chances of success (or, pessimistically, the likelihood of it being forced
down our throats).
It's important to understand the difference between DVD-Video and DVD-ROM.
DVD-Video (often simply called DVD) holds video programs and is played in a
DVD player hooked up to a TV. DVD-ROM holds computer data and is read by a
DVD-ROM drive hooked up to a computer. The difference is similar to that
between Audio CD and CD-ROM. DVD-ROM also includes future variations that
are recordable one time (DVD-R) or many times (DVD-RAM). Most people expect
DVD-ROM to be initially much more successful than DVD-Video. Most new
computers with DVD-ROM drives will also be able to play DVD-Videos (see
6.1).
There's also a DVD-Audio format. The technical specifications for DVD-Audio
are not yet determined.
[1.2] What are the features of DVD-Video?
* Over 2 hours of high-quality digital video (over 8 on a double-sided,
dual-layer disc).
* Support for widescreen movies and standard or widescreen TVs (4:3 and
16:9 aspect ratios).
* Up to 8 tracks of digital audio (for multiple languages), each with up
to 8 channels.
* Up to 32 subtitle/karaoke tracks.
* Multilingual identifying text for title name, album name, song name,
actors, etc.
* Automatic "seamless" branching of video (for multiple story lines or
ratings on one disc).
* Up to 9 camera angles (different viewpoints can be selected during
playback).
* Menus and simple interactive features (for games, quizzes, etc.).
* "Instant" rewind and fast forward, including search to title, chapter,
track, and timecode.
* Durability (no wear from playing, only from physical damage).
* Not susceptible to magnetic fields. Resistant to heat.
* Compact size (easy to handle and store, players can be portable).
Note: Most discs will not contain all features (multiple audio/subtitle
tracks, seamless branching, parental control, etc.).
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 (no
reverse play or reverse step).
* 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.
High-end players may include additional features:
* Component (YUV or RGB) output for highest-quality picture.
* Built-in Dolby Digital AC-3 surround sound decoder.
* Compatiblity with laserdiscs and CDVs.
* Reverse single frame stepping.
* RF output (for TVs with no direct video input).
* English/Spanish/French on-screen display.
[1.3] What's the quality of DVD-Video? Why do some demos look so bad?
DVD has the capability to produce near-studio-quality video and
better-than-CD-quality audio. DVD is vastly superior to videotape, and can
be better than laserdisc (see 2.8.). However, quality depends on many
production factors. Until compression experience and technology improves we
may often see DVDs which are inferior to laserdiscs. Also, since large
amounts of video have already been encoded for VideoCD using MPEG-1, some
early DVDs will use that format (which is no better than VHS) instead of
higher-quality MPEG-2.
DVD video is compressed from studio ITU-R 601 format to MPEG-2 format. This
is a "lossy" compression which removes redundant information (such as
sections 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 "artifacts" such as
blockiness or fuzziness depending on the processing quality and amount of
compression. At average rates of 3.5 Mbps (million bits/second), artifacts
may be occasionally noticeable. Higher data rates result in higher quality,
with almost no perceptible difference from the original master at rates
above 6 Mbps. As MPEG compression technology improves, better quality will
be achieved at lower rates.
Some DVD demos have visible artifacts such as blockiness, color banding,
blurriness, missing detail, and even detail such as a face which "floats"
behind the rest of the moving picture. This is sometimes caused by poor MPEG
encoding, but is just as often cause by bad digital noise reduction during
film-to-tape transfer or before encoding. The Free Willy and Twister
excerpts on the Panasonic demo disc are good examples of this. In any case,
bad demos are not an indication that DVD quality is bad, since other demos
show no artifacts or other problems. Bad demos are simply an indication of
how bad DVD can be if not properly processed and correctly reproduced. Early
demos were shown on prototype players based on prerelease hardware and
firmware. Many demo discs were rushed through the encoding process in order
to be distributed as quickly as possible. Contrary to popular opinion, and
as stupid as it may seem, these demos are not carefully "tweaked" to show
DVD at its best. Also, 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 the high-frequency video and causes distortion,
just as the treble control set too high for a CD causes it to sound harsh.
DVD video has exceptional color fidelity, so muddy or washed out colors are
almost always a problem in the display, not in the DVD player or disc.
DVD audio quality is excellent. One of DVD's audio formats is LPCM (linear
pulse code modulation) with sampling sizes and rates higher than audio CD.
Alternately, audio for most movies is stored as discrete multi-channel
surround sound using Dolby Digital or MPEG-2 audio compression similar to
the surround sound formats used in theaters. As with video, audio quality
depends on how well the encoding was done. Most audio on DVD will be in
Dolby Digital format, which is close to CD quality.
The final assessment can't be made until DVD is in the hands of consumers.
No one can yet guarantee the quality of DVD, just as no one should dismiss
it based on demos or hearsay. And in the end it's a matter of individual
perception.
[1.4] What are the disadvantages of DVD?
* It can't record (yet). (See 1.14 and 4.3.)
* It can't play in reverse.
* It uses digital compression. Poorly compressed audio or video may be
blocky, fuzzy, harsh, or vague.
* It has built-in copy protection and regional lockout. (See 1.11 and
1.10)
* Some DVD players and drives may not be able to read CD-Rs. (See 2.4.3.)
* First-generation DVD players and drives may not be able to read
recordable discs. (See 4.3.)
* It will take years for movies and software to become widely available.
[1.5] When will DVD players and drives be 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.
Available players:
* Japan
o Panasonic: November 1. (A-100, 79,800 yen; A-300, 98,000 yen)
o Toshiba: November 1. (SD-3000, 77,000 yen)
o Sanyo (Toshiba-made): December 1 (?).
o Pioneer: December. (DV-7, 83,000 yen; DVL-9, 133,000 yen;
DVD-K800, 120,000 yen; DVK-1000, 248,000 yen; DV-F21)
o Hitachi (Pioneer-made): December 20.
* Korea
o Samsung: November.
o LG (Goldstar): November.
* US
o Pioneer: February. (DV-500, $600; DVL-700, $1000; DVL-90, $1750)
o Panasonic: February. (A-100, $600; A-300, $750)
* Asia
o Panasonic: February.
Projected player releases (1997):
* Japan
o Akai: January.
o Sony: March 21.
o Victor: April 21. (XV-1000, 93,000 yen)
o JVC: Summer.
o Philips: Summer.
* US
o Samsung: March. (DVD705, $700)
o Toshiba: March. (SD-2006, $600; SD-3006, $750)
o Denon: March. (DVD-2000, $1000)
o Sony: April. (DVP-S7000, $1000)
o Meridian: April (586, $3500!)
o Yamaha: May. (DVD-1000)
o Philips/Magnavox: Spring. (DVD400AT, ~$600)
o Zenith: Spring. (DVD2000)
o Harman Kardon: Spring. (HDV-715)
o AKAI: 2nd quarter. (DV-P1000)
o Onkyo: 2nd quarter. (DVD-7)
o JVC: June.
o RCA (Matsushita-made): Spring (limited), Fall (full rollout).
(RC5200P, $600; RC5500P, $700)
o Faroudja (modified Toshiba): No date. (DV-1000, $5500!)
o Fisher, Hyundai, Goldstar, Hitachi, Mitsubishi, Sharp: No date.
* Europe
o Panasonic: Feb 1 (Germany, A-100, 1300DM; A-300, 1399DM?).
"Shortly after" for rest of Europe.
o Thomson: March. (France, 5000 francs [$893])
o Sony: middle of 1997.
o JVC: Summer.
o Philips: Summer.
o Toshiba: Fall/Winter.
* Asia
o Sony: "After U.S." (after April).
o Toshiba: Summer.
Fujitsu supposedly released the first DVD-ROM-equipped computer on Nov. 6 in
Japan. Toshiba hopes to release a DVD-ROM-equipped computer and a DVD-ROM
drive in Japan in January (moved back from December which was moved back
from November!). DVD-ROM drives from Toshiba and Pioneer began to appear
worldwide in late January. Panasonic and Hitachi drives will be a available
in the 1st quarter of 1997. Samsung drives (and PCs with drives) were be
available in Korea in January, a few months later elsewhere. Philips and LG
drives will be available in the 2nd quarter. Toshiba's Infinia
DVD-ROM-equipped PC will be available Spring 1997. Compaq DVD-PCs are
scheduled for March. Sony's DVD-PCs will be out by Summer.
Note: If you buy a player 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.)
[1.6] When will DVD titles be available, and how many?
As with hardware, rosy predictions of hundreds of movie titles for Christmas
of 1996 have failed to materialize. Warner Home Video originally announced
they would have 250 titles available for the launch of DVD, but now plan to
release only 25 in March. Info-Tech predicts over 600 titles by the end of
1997 and more than 8,000 titles by 2000.
At the November launch of DVD players in Japan, only 15 or so titles were
available, mostly music. Toshiba EMI and Victor (JVC) delayed some DVD title
releases in Japan until mid-November to ensure compatibility with various
DVD players. Papillon was released in Japan on December 5 by AMUSE Video.
Other titles, such as Adventures of Priscilla Queen of the Desert,
Farinelli, Chunking Express, and Les Adventuriers were also released but are
allegedly low-quality MPEG-1 versions.
Warner Home Video began sales in Japan on December 20 with four major
titles: The Assassin, Blade Runner, Eraser, and The Fugitive. Warner
released another four titles on January 23: Batman Forever, Interview with a
Vampire, Outbreak, and Unforgiven. A few other DVD titles (not from Warner!)
released in January included Nutts About Butts, Yum Yum I Love Cum, and
Super Nice Body's Water Melon.
Concorde Video is releasing 12 Monkeys in Germany at the end of February.
This is a special edition, dubbed in German, limited to 5000 copies, priced
at DM49,95. Call +49-711-182-1229 or email mpsbe...@aol.com.
New Line Home Video will release The Mask, Dumb and Dumber, Seven, Rumble In
The Bronx, Mortal Kombat and The Player "as soon as possible," with about 25
titles planned for release in the next year. New Line intends to release
selected titles at the same time as the VHS versions and at sell-through
prices.
Lumivision will release 4 titles on March 19 at $24.95: Tropical Rainforest
(IMAX), Antarctica, Africa: The Serengeti, and Animation Greats (from the
National Film Board of Canada).
Warner Home Video will release movies in March priced at $24.98, over half
of which include extras such as running director commentary,
behind-the-scenes footage, storyboards, Internet browser capability,
director's cut versions, screen tests, and interviews with cast and crew
(those running less than 125 minutes): Batman, Blade Runner: The Director's
Cut, The Bodyguard, The Bridges of Madison County, Bonnie and Clyde,
Casablanca, The Color Purple, Doctor Zhivago, Eraser, The Exorcist, The
Fugitive, The Glimmer Man, Gone with the Wind, GoodFellas, Interview with
the Vampire, JFK: Special Edition Director's Cut, Lethal Weapon, The Road
Warrior, Singin' in the Rain, Space Jam, A Streetcar Named Desire: The
Director's Cut, A Time to Kill, Twister, Unforgiven, and Woodstock: The
Director's Cut. Additional titles to be release later concurrent with VHS:
Mars Attacks!, Michael, Michael Collins, My Fellow Americans, and Sleepers.
Warner Bros. Records Inc. will release three music video titles for $24.98
each on March 24: Eric Clapton - Unplugged, Madonna's The Girlie Show - Live
Down Under, and R.E.M.'s Road Movie. All three feature 5.1-channel audio
remixed from original multitracks. Warner will release five more music
titles in 1997.
Sony's Columbia TriStar Home Video will begin releasing feature film titles
in North America on April 24 to match the delivery of Sony DVD players.
Retail prices are expected to be $24.98 to $26.98, and most will include
options such as dubs in Spanish and French, subtitles in Spanish and Korean,
and English closed-captions. Additional releases will follow every six to
eight weeks. Release 1: Fly Away Home, In the Line of Fire, Jumanji, and
Legends of the Fall. Release 2: Bad Boys, Desperado, Matilda, and Taxi
Driver. Release 3: Bram Stoker's Dracula, First Knight, A League of Their
Own, and Sleepless in Seattle. Release 4: The Cable Guy, The Craft, Little
Women, and Sense and Sensibility. Additional titles include Cliffhanger,
Close Encounters of the Third Kind: Special Edition, Ghostbusters, Glory,
The Last Action Hero, The Net, and Philadelphia. Sony Music
Entertainment/Sony Wonder will release Sesame Street's 25th Anniversary: A
Musical Celebration, Tony Bennett's MTV Unplugged, Streetfighter II -- the
Animated Movie, Odyssey into the Mind's Eye, and Beavis & Butt-head's The
Final Judgement.
MGM Home Entertainment will release 10 titles at sell-through pricing in
April, with another 30 before the end of the year. The first 10 are Species,
Raging Bull, Poltergeist, Rain Man, The Wizard of Oz, GoldenEye, The
Birdcage, Get Shorty, Rocky, and Midnight Cowboy. Additional titles include
Singin' in the Rain, and Casablanca. Most MGM titles will include
soundtracks in English, Spanish, and French.
Polygram Video (Philips partner) will release 10 titles in the US in the
Spring, and another 10 by the end of the year. Nine will be sell-through
priced at $30 to $40: Dead Man Walking, Fargo, The Usual Suspects, Four
Weddings and a Funeral, Lord of the Dance, Three Tenors, U2 Live from
Sydney, Short Cinema, and Ghost in the Shell. The Portrait of a Lady will be
available on DVD the same day as the VHS release, and both will be priced
for rental at about $90.
DVD-ROM software will slowly appear. Approximately 50% of CD-ROM producers
have announced intentions to develop for DVD-ROM. As of Aug. 1996, 30
DVD-ROM titles are supposedly in development for early 1997 release. IDC
expects over 13 percent of all software will be available in DVD-ROM format
by the end of 1998. In one sense, DVD-ROMs are simply larger faster CD-ROMs
and will contain the same material. But DVD-ROMs can also take advantage of
the MPEG video and multi-channel audio capabilities being added to many
DVD-ROM-equipped computers.
The first DVD-ROMs will probably be "The Union Catalogue of Belgian Research
Libraries" from IVS, "PhoneDisc PowerFinder USA One" (which filled 6
CD-ROMs) from Digital Directory Assistance Inc., and "Silent Steel" from
Tsunami Media.
[1.7] How much do players and drives cost?
Mass-market DVD movie players currently list for $600 and up. (See 1.5 for
models and prices.) Within a few years they may approach VCR prices.
InfoTech predicts prices will be as low as $250 by the year 2000.
DVD-ROM drives for computers sell for around $400 to $500. (OEM prices are
under $350.) Prices are expected to drop quickly to current CD-ROM drive
levels.
[1.8] How much do discs cost?
It will vary. Many studios have promised that DVDs will be as cheap or
cheaper than videotapes (and much cheaper than laserdiscs). This remains to
be seen, especially for special editions with supplemental material which
cost much more to produce. Some new releases will initially be priced for
rental (near $80, the same as VHS). But existing titles, which have already
made back money, are expected to be priced below $25 on DVD. Time Warner has
set a price of $24.98 in the U.S. (3,000 yen in Japan). Polygram's
sell-trhough discs are $29.99. Columbia TriStar says its feature film DVDs
will be somewhere between VHS and laserdisc prices.
DVD-ROMs will initially be slightly more expensive than CD-ROMs since there
is more stored on them, they cost more to replicate, and the market is
smaller. But as costs drop and the installed base of drives grow, DVD-ROMs
will probably cost the same as CD-ROMs do today.
[1.9] How quickly will DVD become established?
Nobody knows. Here are a few predictions:
* Toshiba: 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.)
* Pioneer: 400,000 DVD-Video players in 1996, 11 million by 2000. 100,000
DVD-Audio players in 1996, 4 million by 2000.
* InfoTech: 820,000 DVD-Video players in first year, 80 million by 2005.
* Time-Warner: 10 million DVD-Video players in the U.S. by 2002.
* C-Cube: 1 million players and drives in 1997.
* Dataquest: over 33 million shipments of DVD players and drives by 2000.
* Philips: 25 million DVD-ROM drives worldwide by 2000 (10% of projected
250 million optical drives).
* Pioneer: 500,000 DVD-ROM drives sold in 1997, 54 million sold in 2000.
* Toshiba: 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: 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: installed base of 7 million DVD-ROM drives by 2000.
* Intel: 70 million DVD-ROM drives by 1999 (sales will surpass CD-ROM
drives in 1998).
For comparison, there are about 600 million audio CD players and 100 million
CD-ROM drives worldwide. There are about 80 million VCRs in the U.S. and
about 250 million worldwide.
[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).
Therefore they have required that the DVD standard include codes which can
be used to prevent playback of certain discs in certain geographical
regions. Players sold in each region will include a built-in code. The
player will refuse to play discs which are not allowed in the region. This
means that discs bought in one country may not play on players bought in
another country.
Regional codes are entirely optional. Discs without codes will play on any
player in any country. It's not an encryption system, it's just one byte of
information on the disc that the player checks. Some studios have already
announced that only their new releases will have regional codes. Presumably,
once a DVD movie has achieved worldwide release it could be re-released
without coding.
There are 6 regions (also called "locales"). Players and discs are
identified by the region number superimposed on a world globe. If a disc
plays in more than one region it will have more than one number on the
globe.
1: North America
2: Japan, Europe, Middle East, South Africa
3: Southeast Asia (including Hong Kong)
4: Australia, New Zealand, Central/South America
5: Northwest Asia (including Korea?), North Africa
6: China
(See the map at <http://www.unik.no/~robert/hifi/dvd/world.html>.)
It's rumored that Chinese and Hong Kong companies have already developed
chips to defeat the regional coding of a player, and that a Chinese-made
player will play discs regardless of their regional codes. The MPAA and
consumer electronics companies are pursuing legislation to make such devices
illegal in the U.S.
Regional codes also apply to DVD-ROM systems, but will probably not be used
for software. However, operating systems including upcoming versions of
Windows and MacOS will check for regional codes before playing movies from a
DVD-Video. It's not yet known if regional codes will apply to DVD-Audio.
[1.11] What are the copy protection issues?
There are three forms of copy protection used by DVD:
1) Videotape (analog) copying is prevented with a Macrovision 7.0 or similar
circuit in every player. The general term is APS (Analog Protection System).
Computer video cards with composite or s-video (Y/C) output must also use
APS. With Macrovision, composite video and s-video output will have a
rapidly modulated colorburst signal along with pulses in the vertical
blanking signal designed to confuse the automatic-recording-level circuitry
in 95% of consumer VCRs. Unfortunately, this can degrade the picture,
especially with old or nonstandard equipment. Macrovision creates severe
problems for some line doublers. Macrovision is not present on analog
component video output of first-generation players, but is expected to be
required for future players (AGC only, since there is no colorburst in a
component signal). The discs themselves tell the player whether or not to
enable Macrovision AGC with or without Colorstripe. The producer of the disc
decides what amount of copy protection to enable and then pays Macrovision
royalties accordingly. Just as with videotapes, some DVDs are
Macrovision-protected and some aren't. (For Macrovision details see
SGS/Thomson's video encoder datasheet at
<http://www.st.com/stonline/books/ascii/docs/4570.htm>.)
2) Digital video copying is controlled by information on each disc
specifying if the data can be copied. This is a "serial" copy generation
management system (CGMS) designed to prevent copies or copies of copies. Of
course, the equipment making the copy has to abide by the rules. The CGMS
information is also encoded into the analog video signal (on NTSC line 21)
so that digital recorders with analog inputs can recognize it.
3) Because of the potential for perfect digital copies, paranoid movie
studios forced a deeper copy protection requirement into the DVD-Video
standard. Content Scrambling System (CSS) is a form of data encryption that
prevents reading the media files directly from the disc. Most players will
have a decryption circuit that decodes the data before displaying it. No
unscrambled digital output is allowed until work in progress for secure
digital connections is finished. On the computer side, DVD-ROM drives and
video display/decoder hardware or software will exchange encryption keys so
that the video is decrypted just before display by the encoder. This means
that many DVD-ROM drives and video display boards have extra hardware (and
cost) for movie copy protection. Makers of equipment used to display
DVD-Video (drives, chips, display boards, etc.) must license CSS. There is
no charge for a CSS license, but it's currently a lengthy process, so it's
recommended that interested parties apply as soon as possible. As of mid
February, no CSS licenses allow software decoding because of Hollywood's
concerns.
Movie studios and consumer electronics companies want to make it illegal to
defeat DVD copy protection. A co-chair of the legal group of the 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.
DVD-ROM can use CSS for computer data, even though it's designed for audio
and video. However, since DVD-ROM can hold any form of computer data, any
desired encryption scheme could be implemented.
All three forms of copy protection are optional for the producer of a disc.
Movie decryption is also optional for hardware and software playback
manufacturers: a player or computer without decryption capability will only
be able to play unencrypted movies.
These copy protection schemes are designed 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." Even the people who developed
the copy protection standards admit that it won't stop well-equipped
pirates. There are inexpensive devices that defeat analog copy protection,
but Macrovision claims none of the devices are effective against the new
Colorstripe feature (yet).
[1.12] What about DVD-Audio or Music DVD?
The DVD Consortium has decided to seek additional input from the music
industry before defining the DVD-Audio format. An audio standard probably
won't appear until the end of 1997 at the earliest. If the final
specification includes features or formats not present in the current DVD
specification, existing DVD players may not be able to play new DVD-Audio
discs.
Sony is pushing for its Direct Stream Digital (DSD) format, with the support
of Philips. Other organizations such as Acoustic Renaissance for Audio (ARA)
prefer lossless compressed PCM that's more appropriate for studio work and
archiving.
There are rumors that the DVD Consortium is pushing for an 8 cm (CD-single)
size, while the audio industry wants a 12 cm size. (The existing DVD
physical spec allows both sizes.) The audio industry also wants "legacy"
discs which will play on one side in existing CD players and on the other
side in DVD players. There are technical difficulties in doing this, but it
may be possible.
The music industry is also requesting an "embedding signalling" or "digital
watermark" copy protection feature. This applies a digital signature to the
audio in the form of supposedly inaudible "noise" so that new equipment will
recognize copied audio and refuse to play it. Audiophiles claim this
degrades the audio.
In the meantime, the DVD-Video standard includes surround sound audio and
better-than-CD audio (see 3.6). Pioneer is developing audio-only players
based on the audio portion of DVD-Video.
[1.13] Which studios are supporting DVD? Didn't some studios say they won't
support it?
Warner, Columbia TriStar, MGM, Polygram, and others are releasing movies on
DVD (see 1.6). Others have announced support but no movies yet (see 6.2 for
a full list). Disney has expressed concerns over copying, but is closely
involved in DVD development and will most likely jump in once copy
protection is resolved (see 1.11). Paramount and 20th Century Fox have no
immediate plans for DVD. Other studios may hold back, but if DVD is a
success no studio would be foolish enough to not jump on the bandwagon.
[1.14] Will DVD record from VCR/TV/etc?
Short Answer: No. (Not in this century.)
Long answer: The minimum requirement for reproducing audio and video on DVD
is an MPEG video stream and a PCM audio track. (Other streams such as Dolby
Digital audio, MPEG audio, and subpicture are not necessary for the simplest
case.) Basic DVD control codes are also needed. At the moment it's difficult
in real time to encode the video and audio, combine them with the control
codes, and write the whole thing to DVD. Even if you could do all this in
real time it would be too expensive. Prices for DVD production systems are
dropping from millions of dollars to thousands of dollars, but they won't be
in the <$500 range for home use for several years yet. It's possible the
first home DVD recorders will require a digital source of already-compressed
audio and video, such as DBS.
Other obstacles: Price of blank discs may initially be as high as $50 for
record-once, and even higher for erasable. The first generation of
recordable media will hold only about 3/4 as much as pre-recorded discs.
Realtime compression will require higher bit rates for decent quality,
lowering capacity even more. MPEG-2 compression works much better with
high-quality source, so recording from VHS or broadcast/cable may not give
very good results (unless the DVD recorder has prefilters, which raises the
cost).
Don't be confused by DVD-R and DVD-RAM systems, which will be available soon
and will cost over $10,000 (see 4.3). These can record data, but to create
full-featured DVD-Videos would require additional hardware and software to
do video encoding (MPEG-2), audio encoding (Dolby Digital or MPEG or LPCM),
subpicture encoding (run-length-compressed bitmaps), still frame encoding
(MPEG-1 or MPEG-2), control code generation, and multiplexing. And since
this can't be done in real time, you'd also need a 5 to 9 GB hard drive to
premaster the data to.
Some people believe that recordable DVD-Video will never be practical for
consumers to record TV shows or home videos, since digital tape is more cost
effective. On the other hand, digital tape lacks many of the advantages of
DVD such as seamless branching, instant rewind/fast forward, instant search,
and durability, not to mention the coolness of small shiny discs. So once
the encoding technology is fast and cheap enough, and the blank discs are
cheap enough, recordable DVD may be a reality. It will be an interesting
contest between DVD and digital video tape (DV). DV is out already, but
decks cost $4,000.
[1.15] What happens if I scratch the disc? Aren't discs too fragile to be
rented?
Most scratches will cause minor channel data errors that are easily
corrected. 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 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 cause an I/O error on a computer or show up as a momentary glitch in
DVD-Video picture. However, there are many schemes for concealing errors in
MPEG video (see section D.12 of
<http://icib.igd.fhg.de/icib/it/iso/cd_13818-2/read1.html>.
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. Sony and Blockbuster are placing DVD demo kiosks in
select Blockbuster stores. Sony's DVD player includes coupons for free DVD
rentals at Blockbuster.
[1.16] VHS is good enough, why should I care about DVD?
The primary advantages of DVD are quality and extra features (see 1.2). 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 "collectability" factor present with CDs vs. cassette
tapes.
If none of this matters to you, then VHS probably is good enough.
[1.17] Is the packaging different from CD?
Manufacturers are worried about customers assuming DVDs will play in their
CD player, so they would like the packaging to be different. Time Warner is
promoting a "Snapper" package (similar in form to the plastic and paper
"eco" CD packages) which measures 14cm wide x 19cm high x 1.25cm thick (5.5"
x 7.5" x 0.5"). [I measured it by hand, so this may not be exact.] This is
about as wide as a CD jewel box and about as tall as a VHS cassette box.
There is also a proposal from the Video Software Dealers Association for a
package 5 5/8" wide, 7 3/8" high and between 3/8" and 5/8" deep. However, no
one is being forced to use a larger package size and many companies will
undoubtedly use standard jewel cases. It remains to be seen if any package
becomes standard, especially for DVD-ROM.
[1.18] When will double-sided or dual-layer discs appear? Will they work in
all players?
Dual-layer discs are already available. Some replicators plan to produce
double-sided discs, dual-layer discs, and double-dual discs from day one.
Obviously the prices will be higher, but certain producers already require
more space than is available on a single side or single layer.
All DVD players and drives will play dual-layer discs -- it's required by
the spec. All players and drives will also play double-sided discs if you
flip them over. No manufacturer has announced a model that will play both
sides. Pioneer LD/DVD players can play both sides of an LD, but not a DVD.
(See 2.9 for note on reading both sides simultaneously.)
[1.19] Is DVD-Video a worldwide standard? Does it work with NTSC, PAL, and
SECAM?
DVD-V has the same NTSC vs. PAL problem as videotape and laserdisc. DVD-V
supports two mutually-incompatible television systems: 525/60 (NTSC) and
625/50 (PAL). There are three differences between discs intended for
playback on different systems: picture size (720x480 vs. 720x576), display
frame rate (29.97 vs 25), and surround audio (Dolby Digital vs. MPEG-2).
(See 3.4 and 3.6 for details.) Movies are stored at 24 frames/sec but are
encoded for one of the two display rates.
However, a producer can choose to include additional video and audio --at
the expense of playing time-- so that all formats are covered. It's unknown
if players will be able to automatically recognize and play the correct
video track. Some studios include Dolby Digital tracks along with the MPEG
audio tracks on their PAL discs.
Some players will only play NTSC discs, some players will only play PAL
discs, and some will play both. Multi-standard players will output NTSC from
a 525/60 disc and PAL from a 625/50 disc. This requires two TVs or a
multi-standard TV that can display both. Some players partially convert NTSC
to 60 Hz PAL, which requires a 60 Hz PAL TV. It's also possible to make a
standards-converting player that will output standard NTSC from a 625/50
disc or standard PAL from a 525/60 disc, but so far no such players have
been announced.
There are actually three types of DVD players if you count computers. Most
DVD playback software and hardware can play both NTSC and PAL from a
DVD-Video.
[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 occur.
----------------------------------------------------------------------------
[2] DVD's relationship to other products
[2.1] Will DVD replace VCRs?
Not any time soon. DVD is not yet recordable (see 1.14) and it will take a
while before the size of the market drives costs down to VCR levels.
However, DVD has many advantages over VCRs, including fundamentally lower
technology cost for hardware and disc production (which is appealing to
manufacturers), so if DVD is a commercial success it might replace many VCRs
in fifteen to twenty years.
[2.2] Will DVD replace CD-ROM?
Yes. Some CD-ROM drive manufacturers plan to cease CD-ROM drive production
after a few years in favor of DVD-ROM drives. Because DVD-ROM drives can
read CD-ROMs, there is a compatible forward migration path.
[2.3] Can CD-R writers create DVDs?
No. DVD uses a smaller wavelength of laser to allow smaller pits in tracks
that are closer together. The DVD laser must also focus more tightly and at
a different level. In fact, a disc made on a current CD-R writer may not be
readable by a DVD-ROM drive (see 2.4.3). It's unlikely there will be
"upgrades" to convert CD-R drives to DVD-R, since this would probably cost
more than purchasing a new DVD-R drive.
[2.4] Is CD compatible with DVD?
This is actually many questions with many answers:
[Note the differentiation between DVD (general case) and DVD-ROM (computer
data).]
[2.4.1] Is CD audio (CD-DA) compatible with DVD?
Yes. All DVD players and drives will read audio CDs (Red Book). This is not
actually required by the DVD spec, but so far all manufacturers have stated
that their DVD hardware will read CDs. On the other hand, you can't play a
DVD in a CD player. (The pits are smaller, the tracks are closer together,
the data layer is a different distance from the surface, the modulation is
different, the error correction coding is new, etc.)
[2.4.2] Is CD-ROM compatible with DVD-ROM?
Yes. All DVD-ROM drives will read CD-ROMs (Yellow Book). However, DVD-ROMs
are not readable by CD-ROM drives.
[2.4.3] Is CD-R compatible with DVD-ROM?
Maybe. The problem is that CD-Rs (Orange Book Part II) are "invisible" to
DVD laser wavelength because the dye used in CD-Rs doesn't reflect the beam.
This problem is being addressed in many ways. Sony has developed a
twin-laser pickup in which one laser is used for reading DVDs and the other
for reading CDs and CD-Rs. Samsung has also announced dual-laser using a
holographic annular masked lens. These solutions provide complete backwards
compatibility with millions of CD-R discs. Philips has also stated that its
DVD-ROM drives will read CD-Rs. In addition, new CD-R Type II blanks that
will work with CD-ROM and DVD are supposedly in development. In the
meantime, some first-generation DVD-ROM drives and many first-generation
DVD-Video players will not read CD-R media.
[2.4.4] Is CD-RW compatible with DVD?
Supposedly. CD-Rewritable (Orange Book Part III) discs can not be read by
existing CD-ROM drives and CD players. CD-RW has a lower reflectivity
difference, requiring automatic-gain-control (AGC) circuitry. The new
"MultiRead" standard addresses this and some DVD manufacturers have already
suggested they will support it. Supposedly the optical circuitry of DVD-ROM
drives and DVD players is good enough to read CD-RW. CD-RW does not have the
"invisibility" problem of CD-R (see 2.4.3).
[2.4.5] Is VideoCD compatible with DVD?
Probably. It's not required by the DVD spec, but it's trivial to support the
White Book standard since any MPEG-2 decoder can also decode MPEG-1 from a
VideoCD. Most manufacturers have announced that their DVD players will play
VideoCDs. (Panasonic and Pioneer players can play VideoCDs; Toshiba players
can't.) Most computers with DVD-ROM drives will be able to play VideoCDs
(with the right software).
[2.4.6] Is Photo CD compatible with DVD?
Not yet. Since Photo CDs are usually on CD-R media, they may suffer from the
CD-R problem (see 2.4.3). That aside, DVD players could support Photo CD
with a few extra chips and a license from Kodak. No one has announced such a
player. Most DVD-ROM drives will read Photo CDs (if they read CD-Rs) since
it's trivial to support the XA and Orange Book multisession standards. The
more important question is, "Does the OS or application support Photo CD?"
but that's beyond the scope of this FAQ.
[2.4.7] Is CD-i compatible with DVD?
In general, no. Most DVD players will not play CD-i (Green Book) discs.
However, Philips has announced that it will make a DVD player that supports
CD-i. Some people expect Philips to create a "DVD-i" format in attempt to
breathe a little more life into CD-i (and recover a bit more of the billion
or so dollars they've invested in it).
[2.4.8] Is Enhanced CD compatible with DVD?
Yes. DVD players will play music from Enhanced CDs (Blue Book, CD Plus, CD
Extra), and DVD-ROM drives will play music and read data from Enhanced CDs.
[2.4.9] Is CD+G compatible with DVD?
Only the Pioneer DVL-9 player and Pioneer karaoke DVD models DV-K800 and
DVK-1000 are known to support CD+G. Most other DVD-V players probably won't
support this mostly obsolete format. All DVD-ROM drives support CD+G, but
special software is required to make use of it.
[2.4.10] Is CDV compatible with DVD?
Sort of. CDV, sometimes called Video Single, is actually a weird combination
of CD and laserdisc. Part contains 20 minutes of digital audio playable on
any CD or DVD player. The other part contains 5 minutes of analog video (and
digital audio) in laserdisc format, playable only on a CDV-compatible
system. However, Pioneer and others have announced combination players that
will play DVDs, laserdiscs, and CDVs.
[2.5] Is laserdisc compatible with DVD?
No. Standard DVD players will not play laserdiscs, and you can't play a DVD
disc on any standard laserdisc player. (Laserdisc uses analog video, DVD
uses digital video; they are very different formats.)
However, Pioneer and Samsung have announced combo players that will play
laserdiscs and DVDs (and also CDVs and audio CDs). Denon is rumored to have
an LD/DVD player in the works also.
[2.6] Will DVD replace laserdisc? Should I buy laserdisc now or wait for DVD
and HDTV?
DVD will probably replace laserdisc, but not for a very long time. Laserdisc
is well established as a videophile format. There are over 9,000 laserdisc
titles in the US and a total of over 35,000 worldwide that can be played on
over 7 million laserdisc players. It will take DVD many years to reach this
point. Until then laserdisc has the superiority of tenure. Pioneer and other
laserdisc companies have committed to supporting it for years to come.
There's no reason to stop buying laserdiscs, especially rare titles that may
not appear on DVD for a long while if ever. Even laserdisc owners who buy
DVD will not immediately replace their collection. Laserdisc and DVD will
co-exist for a long while.
In December of 1996 the FCC approved the U.S. DTV standard. HDTVs may appear
as early as 1998 but they will be very expensive and won't become widespread
for many years. DVD will look better on HDTVs but it won't provide high
resolutions (see 2.9).
The answer to this question depends on you. If you need to be the first on
your block with the latest gadget, you may want to get a DVD player or a
combination LD/DVD player now. If you prefer to wait until DVD prices drop
and bugs get worked out, you may have a lengthy wait. If you think DVD isn't
a big enough improvement and decide to hold out for HTDV, you'll be in for
an even longer wait. In the meantime you could be enjoying the large
selection of laserdisc titles. Or you could start saving now for DVD (which
won't be too expensive) or HDTV (which will be). If you buy a laserdisc
player, a surround sound system, and speakers, they will be still be useful
even after DVD and HDTV come out. HDTV will require a new TV set, but it
will be compatible with the rest of your gear.
Unfortunately, anticipation of DVD is already hurting laserdisc. In 1996
laserdisc player sales were down 37% even though sales of VCRs and
hi-fi/surround systems were up. But silver lining in this cloud is that disc
prices may come down. (Laserdisc movie sales were only down 2.5% in 1996.)
[2.7] How does DVD compare to laserdisc?
This is a dangerous question to answer, given the legions of laserdisc
fanatics who would rather have their laserdiscs pried from their cold dead
fingers than switch! But I'm a bit fanatical myself: I've used laserdiscs
since 1979 and I work for a company whose major product is laserdiscs; so
I'll give it a shot. <Putting on flameproof suit....>
DVD improves on laserdisc (LD) in many ways:
* Features: DVD has the same basic features as CLV LD (scan, pause,
search) and CAV LD (freeze, slow) and adds branching, multiple camera
angles, parental control, video menus, interactivity, etc. But unlike
LD, DVD can't play or step backwards or play in either direction at
fast speeds (until the players get more video memory).
* Capacity: Single-layer DVD holds over 2 hours, dual-layer holds over 4
hours. CLV LD holds one hour per side, CAV holds half an hour. DVD can
also hold hundreds of still pictures accompanied by over 20 hours of
audio and text.
* Convenience: An entire movie fits on one side of a DVD, so there's no
need to flip the disc or wait for the player to do it. DVDs are smaller
and easier to handle. DVD players can be portable, similar to CD
players. Discs can be easily and cheaply sent through the mail.
* Noise: Most LD players make a whirring noise that can be heard during
quiet segments of a movie. Some DVD players are as quiet as CD players,
others are noisier.
* Audio: DVD has generally better audio. LD has 2 audio tracks: analog
and digital. Surround sound is available by using one analog channel
for AC-3 or both digital channels for DTS. DVD has up to 8 audio
tracks. LD uses PCM audio sampled with 16 bits at 44 kHz. DVD LPCM
audio can use 16, 20, or 24 bit samples at 48 or 96 kHz (although PCM
won't be used with most movies). LD has surround audio in Dolby Digital
(AC-3) and DTS formats. DVD uses the same Dolby Digital surround sound,
but can actually go to a higher data rate for better quality (448 kbps
instead of 384) and can optionally include DTS at a higher data rate.
* Video: DVD has the potential for better video. LD suffers from
degradation inherent in analog storage and in the composite NTSC or PAL
video signal. DVD uses digital video, and even though it's heavily
compressed, hundreds of video professionals have seen demos of MPEG-2
video and concluded that properly and carefully encoded it's virtually
indistinguishable from studio D-1 masters. Nevertheless, this doesn't
mean that the video quality of DVD, especially at first, WILL be better
than LD. Only that it CAN be better. Also keep in mind that the average
television is of insufficient quality to show much difference between
LD and DVD. Home theater systems are needed to take advantage of the
improved quality. The arguments about DVD quality vs. LD quality will
rage for a long time. The only final answer is to compare them side by
side and form your own opinion.
* Resolution: In numerical terms DVD has 345,600 pixels (720x480), which
is 1.3 times LD's approximately 272,160 pixels (567x480). Widescreen
DVD has 1.7 times the pixels of letterboxed LD (or 1.3 times anamorphic
LD). As for horizontal lines of resolution, DVD ~= 540, LD ~= 425, and
VHS ~= 240. (All figures are for NTSC, not PAL.)
* Support: Laserdisc has the edge here for a while. But there are more
announced DVD players than there are LD players. Many new computers
will be able to play DVD-Videos. Some studios have said they eventually
expect to release more DVD titles than LD titles.
* Price: DVD players are not yet cheaper than the cheapest LD player, but
the success of DVD-ROM will inevitably drive the price to level of CD
players. Most movies on DVD are priced less than on LD.
There are concerns that regional coding (see 1.10) and Macrovision copy
protection (see 1.11) will make DVD less usable than laserdisc. This may be
confirmed when DVD is in the hands of consumers.
Again, it will take years for DVD to reach the number of titles, installed
base, and even quality of production that laserdisc has. DVD and laserdisc
will coexist for at least another decade. But the potential of DVD can't be
ignored -- it's the most likely long-term successor to laserdisc.
For more laserdisc info, see the Laserdisc FAQ at
<http://www.cs.tut.fi/~leopold/Ld/FAQ/index.html>.
[2.8] Can I modify or upgrade my laserdisc player to play DVD?
It's not likely. DVD circuitry is completely different, the pickup laser is
a different wavelength, the tracking control is more precise, etc. No
hardware upgrades have been announced, and in any case they would probably
be more expensive than buying a DVD player to put next to the laserdisc
player.
[2.9] Will DVD support HDTV (DTV/ATV)?
HTDV is not directly supported by DVD-Video, but the designers have it in
mind. HDTV standards were not finalized when DVD was developed, so DVD's
MPEG-2 video resolutions and frame rates are closely tied to NTSC and PAL
video formats. DVD does support the 16:9 ratio of HDTV. Since HDTV uses
MPEG-2 it could be easy to "upgrade" the DVD format. The limited data rate
of DVD may make it difficult to support high-quality HDTV, but this might be
solved by increasing the spin rate (a double-speed DVD-ROM drive exceeds the
19 Mbps US ATV data rate) or by using higher-capacity blue or purple lasers.
Either case will require new players and additional standards. There are
rumors that future DVD players will convert existing DVD-Video to the
standard-resolution progressive scan ATV format (704x480x30P).
The resolution of ATV in the US will probably correspond to the ATSC
recommendations: 1280x720/60, 1920x1080/30. These are 2.7 and 6 times the
resolution of DVD, and the first is twice the frame rate. There's also an
SDTV (standard definition) mode of 704x480/60 which is similar to DVD's
720x480/30 mode but double the frame rate. The ITU-R is working on BT.709
HDTV standards of 1125/60 (1920x1035/30) (same as SMPTE 240M, similar to
Japan's analog MUSE HDTV) and 1250/50 (1920x1152/25) which may be used in
Europe. The latter is 5.3 times the resolution of DVD's 720x576/25 format.
It's quite likely that HDTV displays will support component digital video
connections (YCrCb) or digital data connections (FireWire/IEEE 1394). This
will provide the best possible reproduction of DVD-Video, especially in
widescreen mode. Once DVD players have digital connections they may be able
to ouput any kind of data (even formats newer than the player) to any sort
of external display or converter.
Some have speculated that a "double-headed" player reading both sides of the
disc at the same time could double the data rate for applications such as
HDTV. This is currently impossible since the track spirals go in opposite
directions. The DVD specs would have to be changed to allow reverse spirals
on the second side. Precise alignment would be required in both the radial
and angular dimensions to get both sides in sync.
----------------------------------------------------------------------------
[3] DVD technical details
[3.1] What are the outputs of a DVD player?
Most DVD players will have the following output connections:
Video:
- Composite video (CVBS) RCA/Cinch (NTSC or PAL)
- Y/C (s-video) (NTSC or PAL)
Audio:
- Dual RCA stereo analog audio (with Dolby Surround encoding)
- Digital audio (IEC-958 II RCA coax (S/P DIF) or EIAJ CP-340 optical
(Toslink)). Raw digital audio (AC-3, MPEG-2, PCM, or optional DTS or SDDS)
requires an external decoder or an amplifier/receiver with built-in decoder.
(Note: The digital AC-3 audio output is not the same as the RF AC-3 output
on laserdisc players.)
Some players may have additional connections:
- Component analog video, NTSC or PAL (YUV: 3 RCA connectors, RGB: SCART
connector or 3 RCA)
- RF video output for connecting via channel 3 or 4 to TV without direct
input. (Panasonic DVD-A300)
- 6 RCA jacks for surround sound output from built-in decoder. (Panasonic
DVD-A300, RCA)
- AC-3 RF output on combo LD/DVD players. LD AC-3 on RF output only, DVD
AC-3 on coax/optical outputs only. (Pioneer DVL-90, DV-50/DV-500)
Most of the DVD players with component outputs use YUV, which is
incompatible with RGB. European players with SCART connectors have RGB
outputs. YUV to RGB transcoders are available for $200-$300.
No DVD players have yet been announced with digital video outputs, but it's
expected that at some point digital output will be available using FireWire
(IEEE 1394) connectors (see <http://firewire.org>).
[3.2] How do I hook up a DVD player?
It depends on your audio/video system and your DVD player. Most DVD players
have 2 or 3 video hookup options and 3 audio hookup options. Choose the
option with the best quality (indicated below) that is supported by your
video and audio systems.
Video
* Component video (best): Some U.S. and Japanese players have component
YUV video output in the form of 3 RCA or BNC connectors. Connectors may
be labelled YUV, or YPbPr, or Y/B-Y/R-Y, and may be colored
green/red/blue. Some players have RGB component video output via a
20-pin SCART connector or 3 RCA or BNC connectors labelled R/G/B. Hook
cables from the three video outputs of the player to the three video
inputs of the display, or a SCART cable from the player to the display.
Note: Connecting YUV to RGB will not work; a converter box is required.
* S-video (good): Almost all players have s-video output. Hook an s-video
cable from the player to the display (or to an A/V receiver that can
switch s-video). The round, 5-pin connectors may be labelled Y/C,
s-video, or S-VHS.
* Composite video (ok): All DVD players have standard RCA (Cinch)
baseband video connectors. Hook a standard video cable from the player
to the display (or to an A/V receiver ). The connectors are usually
yellow and may be labelled video, CVBS, composite, or baseband.
* RF video (worst): A few players have RF video output for televisions
with only an antenna connection. Connect a coax cable from the player
to the TV. A 300 ohm to 75 ohm adapter may be needed. Tune the TV to
channel 3 or 4 and set the switch on the back of the player to match.
Audio
* Component audio (best): A few DVD players have built-in Dolby Digital
(AC-3) or MPEG-2 audio decoders. A receiver/amplifier with 6 inputs (or
more than one amplifier) is required. Hook 6 audio cables to the RCA
connectors on the player and to the matching connectors on the
receiver/amplifier. Some receivers require an adapter cable with a
DB-25 connector on one end and RCA connectors on the other.
* Digital audio (best): Almost all DVD players have digital audio outputs
for Dolby Digital (AC-3), MPEG-2 audio, PCM audio, DTS, and SDDS. For
DD AC-3 or MPEG-2, the appropriate decoder is required in the receiver
or as a separate audio processor. For PCM, a receiver with built-in DAC
or an outboard DAC is required. DTS and SDDS are not used on most
discs; they require the appropriate decoder in the receiver or a
separate audio processor. Some DVD players have coax connectors, some
have fiber optic connectors, and many have both. Hook a 75-ohm coax
cable or a fiber-optic cable between the player and the
receiver/processor. You may need to select the default audio track by
using the player setup menu or a switch on the back of the player.
Note: Make sure you use an audio quality cable; a cheap RCA patch cable
may cause the audio to not work. Note: hooking a coax cable to the
AC-3/RF input may not work, since DVD digital audio is not in RF format
(see below).
* Stereo/surround audio (ok): All DVD players include two RCA connectors
for stereo output. Any disc with Dolby Digital or MPEG-2 audio will
automatically be downmixed to Dolby Surround output for connection to a
regular stereo system or a Dolby Surround/Pro Logic system. Connect two
audio cables between the player and a receiver, amplifier, or TV.
Connectors may be labelled audio, or left/right; left is usually white,
right is usually red.
* RF digital audio (LD only): Combination LD/DVD players include AC-3 RF
output for digital audio from laserdiscs. Hook a coax cable to the AC-3
RF input of the receiver/processor. Note: digital audio from DVDs does
not come out of the RF output, it comes out of the optical/coax
outputs. Analog audio from LDs will come out the stereo connectors, so
three separate audio hookups are required to cover all variations.
[3.3] What are the sizes and capacities of DVD?
There are many variations on the DVD theme. There are two physical sizes: 12
cm (4.7 inches) and 8 cm (3.1 inches), both 1.2 mm thick. This is the same
form factor as CD. A disc can be single-sided or double-sided. Each side can
have one or two layers of data. The amount of video a disc can hold depends
on how much audio accompanies it and how heavily the video and audio are
compressed. The oft-quoted figure of 133 minutes is apocryphal: a DVD with
only one audio track easily holds over 160 minutes, and a single layer can
actually hold up to 6 hours of video and audio if it's heavily compressed
(which reduces the quality).
At a rough average rate of 4.7 Mbps (3.5 Mbps for video, 1.2 Mbps for three
5.1-channel soundtracks), a single-layer DVD holds around 135 minutes. A
two-hour movie with three soundtracks can average 5.2 Mbps. A dual-layer
disc can hold a two-hour movie at an average of 9.5 Mbps, which practically
guarantees no compression artifacts.
Capacities of DVD-ROM and DVD-Video:
For reference, a CD-ROM holds about 650 MB (megabytes), which is 0.64 GB
(gigabytes) or 0.68 G bytes (billion bytes). In the list below, SS/DS means
single-/double-sided, SL/DL means single-/dual-layer, GB means gigabytes
(2^30), G means billions of bytes (10^9).
* DVD-5 (12cm, SS/SL): 4.38 GB (4.7 G) of data, over 2 hours of video
* DVD-9 (12cm, SS/DL): 7.95 GB (8.5 G), about 4 hours
* DVD-10 (12cm, DS/SL): 8.75 GB (9.4 G), about 4.5 hours
* DVD-18 (12cm, DS/DL): 15.90 GB (17 G), over 8 hours
* DVD-1? (8cm, SS/SL): 1.36 (1.4 G), about half an hour
* DVD-2? (8cm, SS/DL): 2.48 GB (2.7 G), about 1.3 hours
* DVD-3? (8cm, DS/SL): 2.72 GB (2.9 G), about 1.4 hours
* DVD-4? (8cm, DS/DL): 4.95 GB (5.3 G), about 2.5 hours
Tip: It takes about two gigabytes to store one hour of average video.
DVD-R (recordable) and DVD-RAM (erasable):
Most likely will only be available as 12cm, single-layer. The standards
still aren't finalized and there may initially be different sizes varying
from 2.6 to 4 G bytes. See 4.2 for details.
[3.4] What are the video details?
DVD-Video is an application of DVD-ROM. DVD-Video is also an application of
MPEG-2. This means the DVD format defines subsets of these standards to be
applied in practice as DVD-Video. DVD-ROM can contain any desired digital
information, but DVD-Video is limited to certain data types designed for
television reproduction.
A disc has one track (stream) of MPEG-2 constant bit rate (CBR) or variable
bit rate (VBR) compressed digital video. A limited version of MPEG-2 Main
Profile at Main Level (MP@ML) is used. SP@ML is also supported. MPEG-1 CBR
and VBR video is also supported. 525/60 (NTSC, 29.97 interlaced frames/sec)
and 625/50 (PAL, 25 interlaced frames/sec) video systems are supported.
Coded frame rates of 24 fps progressive or interlaced scan from film, 25 fps
interlaced scan from PAL video, and 29.97 fps interlaced scan from NTSC
video are supported. In the case of 24 fps, the data includes MPEG-2
repeat_first_field flags to tell the decoder to perform 3-2 pulldown for 60
(59.94) Hz displays and 2-2 pulldown for 50 Hz displays. (No current players
convert from PAL to NTSC or NTSC to PAL. See 1.19.)
See the MPEG page <http://www.mpeg.org> for more information on MPEG-2
video.
Picture dimensions are max 720x480 (29.97 frames/sec) or 720x576 (25
frames/sec). Pictures are subsampled from ITU-R 601 at 4:2:0, which
allocates an average of 12 bits/pixel. The uncompressed source is 124.416
Mbps (720x480x12x30 or 720x576x12x25). Using the traditional (and rather
subjective) television measurement of "horizontal lines of resolution" DVD
has 540 lines on a standard TV (720/(4/3)) and 405 on a widescreen TV
(720/(16/9)). VHS has about 230 lines and laserdisc has about 425.
Maximum bitrate is 9.8 Mbps (but will always be less to allow for audio).
The "average" bitrate is 3.5 but depends entirely on the length, quality,
amount of audio, etc. This is a 36:1 reduction from uncompressed 124 Mbps.
Raw channel data is read off the disc at a constant 26.16 Mbps. After 8/16
demodulation it's down to 13.08 Mbps. After error correction the user data
stream goes into the track buffer at a constant 11.08 Mbps. The track buffer
feeds system stream data out at a variable rate of up to 10.08 Mbps. After
system overhead, the maximum rate of combined elementary streams (audio +
video + subpicture) is 9.8. MPEG-1 video rate is limited to 1.856 Mbps.
Still frames (encoded as MPEG-2 I-frames) are supported and can be displayed
indefinitely. These are generally used for menus. Still frames can be
accompanied by audio.
A disc also can have up to 32 subpicture streams that overlay the video for
subtitles, karaoke, menus, simple animation, etc. These are full-screen,
run-length-encoded bitmaps limited to four contrast values and four colors
per pixel (contrast and color are selected for a group of subpictures from
palettes of 16). Subpicture includes built-in effects such as scroll, move,
and fade. The maximum subpicture data rate is 3.36 Mbps, with a maximum size
per frame of 52 k bytes.
[3.5] How do the aspect ratios work?
Video can be stored on a DVD in 4:3 format (standard TV shape) or 16:9
(widescreen). The 16:9 format is "anamorphic," meaning the picture is
squeezed horizontally to fit a 4:3 rectangle then unsqueezed during
playback. DVD players output widescreen video in three different ways:
* letterbox (for 4:3 screens)
* pan & scan (for 4:3 screens)
* anamorphic or unchanged (for wide screens)
Note: Playback of widescreen material can be restricted. Programs can be
marked for the following display modes:
- 4:3 full frame
- 4:3 LB (for automatically setting letterbox expand mode on widescreen TV)
- 16:9 LB only (player not allowed to pan & scan on 4:3 TV)
- 16:9 PS only (player not allowed to letterbox on 4:3 TV)
- 16:9 LB or PS (viewer can select pan & scan or letterbox on 4:3 TV)
For letterbox mode the player uses a "letterbox filter" that creates black
bars at the top and the bottom of the picture (60 lines each for NTSC, 72
for PAL). This leaves 3/4 of the height remaining, creating a shorter but
wider rectangle. In order to fit this shorter rectangle, the picture is
squeezed vertically by combining every 4 lines into 3. This compensates for
the original horizontal squeezing, resulting in the movie being shown in its
full width. The vertical resolution is reduced from 480 lines to 360.
For pan & scan mode the video is unsqueezed to 16:9 and a portion of the
image is shown at full height on a 4:3 screen by following "center of
interest" coordinates that are encoded in the video stream according to the
preferences of the people who transferred the film to video. The pan & scan
"window" is 75% of the full width, which reduces the horizontal pixels from
720 to 540.
For anamorphic mode the video is stretched back out by widescreen equipment
to its original width.
Video stored in 4:3 format is not changed by the player. It will appear
normally on a 4:3 screen. Widescreen systems will either stretch it
horizontally or add black bars to the sides.
This gets even more complicated because most movies today are shot with a
"soft matte." (The cinematographer has two sets of frame marks in her
viewfinder, one for 1.33 (4:3) and one for 1.85, so she can allow for both
formats). A few movies are even wider, such as the 2.35 ratio of Panavision.
Since most movies are wider than 1.78 (16:9), one of at least 3 methods must
be used during transfer to make it fit the 1.78 rectangle: 1) add additional
thin black bars to the top and bottom; 2) include a small amount of extra
picture at the top and bottom from the soft matte area; 3) crop the sides,
possibly with a small amount of pan & scan. With the first two methods, the
difference between 1.85 and 1.78 is so small that the letterbox bars or
extra picture are hidden in the overscan area of most televisions.
Nevertheless, and especially with 2.35 movies, some DVD producers may choose
to put 16:9 source on one side of the disc and 4:3 source on the other,
rather than adding pan & scan information. This way no letterbox bars will
appear in the pan & scan version and its resolution won't be reduced. This
also allows the full-frame 4:3 version of a movie to be used, with minimal
or no pan & scan.
The 16:9 anamorphic format causes no problems with line doublers, since they
simply double the lines on their way to the widescreen display which then
stretches out the lines.
Different pixel aspect ratios (none of them square) are used for each aspect
ratio and resolution:
720x480 720x576
4:3 0.889 1.067
16:9 1.185 1.422
[3.6] What are the audio details?
The DVD-Audio format is not yet specified. These details are for audio
tracks on DVD-Video. Some DVD manufacturers such as Pioneer are developing
audio-only players using the DVD-Video format.
A disc can have up to 8 audio tracks (streams). Each track can be in one of
three formats:
* Dolby Digital (AC-3): 1 to 5.1 channels
* MPEG-2 audio: 1 to 5.1 or 7.1 channels
* PCM: 1 to 8 channels.
Two additional optional formats are supported: DTS and SDDS. Both require
external decoders.
The ".1" refers to a low-frequency effects (LFE) channel that connects to a
subwoofer.
All five audio formats support karaoke mode, which has two channels for
stereo (L and R) plus an optional melody channel (M) and two optional vocal
channels (V1 and V2).
Discs containing 525/60 (NTSC) video must use PCM or Dolby Digital on at
least one track. Discs containing 625/50 (PAL) video must use PCM or MPEG-2
audio on at least one track. Additional tracks may be in any format. Many
MPEG-2 discs include Dolby Digital.
For stereo output (2 RCA connectors), all players will downmix from 5.1 or
7.1 multi-channel (if present on the disc) to Dolby Surround stereo (i.e., 5
channels will be matrixed into 2 channels to be decoded to 4 by an external
Dolby Surround or Pro Logic processor). Both Dolby Digital and MPEG-2
support 2-channel Dolby Surround as the source in cases where the disc
producer can't or doesn't want to remix the original onto discrete channels.
This means that a DVD labelled as having Dolby Digital sound may only use
the L/R channels for surround or "plain" stereo. Even movies with old
monophonic soundtracks may use Dolby Digital -- but only 1 or 2 channels.
The downmix process is auditioned when the disc is prepared, and if the
quality is not adequate the audio can be tweaked or a separate L/R Dolby
Surround track can be added. Tests have shown that neither is usually
necessary.
Linear PCM is uncompressed (lossless) digital audio, the same format used on
CDs. It can be sampled at 48 or 96 kHz with 16, 20, or 24 bits/sample.
(Audio CD is limited to 44.1 kHz at 16 bits.) There can be 1, 2, 5, or 8
channels. The maximum bitrate is 6.144 Mbps, which limits sample rates and
bit sizes with 5 or 8 channels. It's generally felt that the 96 dB dynamic
range of 16 bits or even the 120 dB range of 20 bits combined with a
frequency response of up to 22,000 Hz from 48 kHz sampling is adequate for
high-fidelity sound reproduction. However, additional bits and higher
sampling rates are useful in studio work, noise shaping, advanced digital
processing, and three-dimensional sound field reproduction. DVD players are
required to support all the variations of LPCM, but some of them may
subsample 96 kHz down to 48 kHz, and some may not use all 20 or 24 bits.
Dolby Digital is multi-channel digital audio, compressed using AC-3 coding
technology from original PCM with a sample rate of 48 kHz at 16 bits. The
bitrate is 64 kbps to 448 kbps, with 384 being the normal rate for 5.1
channels and 192 being the normal rate for stereo (with or without surround
encoding). The channel combinations are (front/surround): 1/0, 1+1/0 (dual
mono), 2/0, 3/0, 2/1, 3/1, 2/2, and 3/2. The LFE channel is optional with
all 8 combinations. For details see ATSC document A/52
<http://www.atsc.org/document.html>.
MPEG audio is multi-channel digital audio, compressed from original PCM
format with sample rate of 48 kHz at 16 bits. Both MPEG-1 and MPEG-2 formats
are supported. The variable bitrate is 32 kbps to 912 kbps, with 384 being
the normal average rate. MPEG-1 is limited to 384 kbps. There can be 1, 2,
5.1 or 7.1 channels [any more?]. The 7.1 channel format adds left-center and
right-center channels, but will probably be rare for home use. MPEG-2
surround channels are in an extension stream matrixed onto the MPEG-1 stereo
channels, which makes MPEG-2 audio backwards compatible with MPEG-1 hardware
(an MPEG-1 system will only see the two stereo channels.)
DTS is an optional multi-channel (5.1) digital audio format, compressed from
PCM at 48 kHz. The data rate is from 64 kbps to 1536 kbps. Channel
combinations are (front/surround): 1/0, 2/0, 3/0, 2/1, 2/2, 3/2. The LFE
channel is optional with all 6 combinations.
SDDS is an optional multi-channel (5.1 or 7.1) digital audio format,
compressed from PCM at 48 kHz. The data rate can go up to 1280 kbps.
A DVD-5 with only one surround stereo audio stream (at 192 kbps) can hold
over 55 hours of audio. A DVD-18 can hold over 200 hours.
[3.7] How do the interactive features work?
DVD-Video players (and software DVD-Video navigators) support a command set
that provides rudimentary interactivity. The main feature is menus, which
are present on almost all discs to allow content selection and feature
control. Each menu has a still-frame graphic and up to 36 highlightable,
rectangular "buttons" (only 12 if widescreen, letterbox, and p&s modes are
used). Remote control units have four arrow keys for selecting onscreen
buttons, plus numeric keys, select key, menu key, and return key. Additional
remote functions may include freeze, step, slow, fast, scan, next, previous,
audio select, subtitle select, camera angle select, play mode select, search
to program, search to part of title (chapter), search to time, and search to
camera angle. Any of these features can be disabled by the producer of the
disc.
Additional features of the command set include simple math (add, subtract,
multiply, divide, modulo, random), bitwise and, bitwise or, bitwise xor,
plus comparisons (equal, greater than, etc.), and register loading, moving,
and swapping. There are 24 system registers for information such as language
code, audio and subpicture settings, and parental level. There are 16
general registers for command use. A countdown timer is also provided.
Commands can branch or jump to other commands. Commands can also control
player settings, jump to different parts of the disc, and control
presentation of audio, video, subpicture, camera angles, etc.
DVD-V content is broken into "titles" (movies or albums), and "parts of
titles" (chapters or songs). Each part of title is a "program", which is
made up of "cells" linked together by a "program chain." Programs can be
defined as random play (may repeat) or shuffle play (random order but no
repeats). Individual cells may be used by more than one program chain, which
is how parental management and seamless branching are accomplished:
different program chains define different sequences through mostly the same
material.
Additional material for camera angles and seamless branching is interleaved
together in small chunks. The player jumps from chunk to chunk, skipping
over unused angles or branches, to stitch together the seamless video. Since
angles are stored separately, they have no direct effect on the bitrate but
they do affect the playing time. Adding 1 camera angle for a program roughly
doubles the amount of space it requires (and cuts the playing time in half).
----------------------------------------------------------------------------
[4] DVD and computers
[4.1] Can I play DVD movies on my computer?
Only if your computer has the right stuff. In addition to a DVD-ROM drive,
you must have extra hardware to decode MPEG-2 video and Dolby
Digital/MPEG-2/LPCM audio. The computer operating system or playback system
must support regional codes and be licensed to decrypt copy-protected
movies. You may also need software that can read the MicroUDF format used to
store DVD data files and interpret the DVD control codes. It's estimated
that 10-30% of new computers with DVD-ROM drives will include decoder
hardware, and that most of the remaining DVD-ROM computers will include
movie playback software. Hardware upgrade kits can also be purchased
separately for $400 to $1,000. (OEM price for playback hardware is about
$200.)
Note: The recently released QuickTime MPEG Extension for MacOS is for MPEG-1
only and does NOT play MPEG-2 DVD-Video.
Some DVD-Videos and many DVD-ROMs will use video encoded using MPEG-1
instead of MPEG-2. Many existing computers have MPEG-1 hardware built in or
are able to decode MPEG-1 with software.
CompCore Multimedia and Mediamatics make software to play DVD-Video movies
(SoftDVD and DVD Express). Both require at least a 233 MHz Pentium MMX with
AGP and an IDE/SCSI DVD-ROM drive with bus mastering DMA support to achieve
about 20 frame/sec film rates (or better than 300 MHz for 30 frame/sec
video), and can decrypt copy-protected movies (see 1.11). The software
"navigators" support most DVD-Video features (menus, subpictures, etc.) and
can emulate a DVD-Video remote control.
Both companies have defined standards to allow certain MPEG decoding tasks
to be performed by hardware on a video card and the remainder by software.
Video graphics controllers with this feature are being called "DVD MPEG-2
accelerated." (The Mediamatics standard is called MVCCA.)
If you have at least a 433 MHz Alpha workstation you'll be able to play DVD
movies at full 30 fps in software.
[4.2] What are the features and speeds of DVD-ROM drives?
Most DVD-ROM drives have a seek time of 150-200 ms, access time of 200-250
ms, and data transfer rate of 1.2 MB/s (10.08*10^6/8/2^20) with burst
transfer rates of up to 12 MB/s or higher. The data transfer rate from
DVD-ROM discs is roughly equivalent to an 8x CD-ROM drive. DVD spin rate is
about 3 times faster than CD, so when reading CD-ROMs, some DVD-ROM drives
transfer data at 3x speed while others are faster. 2x and 3x DVD-ROM drives
are already in the works. Hitachi is shipping samples of a 2x DVD-ROM drive
which also reads CDs at 20x.
Connectivity is similar to that of CD-ROM drives: EIDE (ATAPI), SCSI-2, etc.
All DVD-ROM drives have audio connections for playing audio CDs. No DVD-ROM
drives have been announced with DVD audio or video outputs (which would
require internal audio/video decoding hardware).
DVD-ROMs use a MicroUDF/ISO 9660 bridge file system. The OSTA UDF file
system will eventually replace the ISO 9660 system of CD-ROMs, but the
bridge format provides backwards compatibility until operating systems
support UDF.
[4.3] What about recordable DVD-ROM: DVD-R and DVD-RAM?
There are two recordable versions of DVD-ROM: DVD-R (recordable once) and
DVD-RAM (erasable and recordable many times), with capacities varying from
2.6 to 3.95 G bytes. DVD-R is close to finalization, and is expected to be
compatible with all DVD drives. Two competing formats have been proposed for
DVD-RAM. DVD-R will use organic dye polymer technology like CD-R. DVD-RAM
will probably use phase-change technology. DVD-RAM discs are supposed to be
readable by all DVD-ROM drives and DVD-Video players, but current proposals
may require support for defect lists, which is not in the initial DVD spec,
so first-generation DVD drives and players probably won't read DVD-RAM
discs. The technology will improve to eventually support 4.7 G bytes, which
is crucial for desktop DVD-ROM and DVD-Video production.
Initial price for DVD-R drives is expected to start at about $11,000 and
drop within a year to around $2,000. DVD-RAM drives will be even more
expensive. Initial price for blank DVD-Rs will be $40-$50, with DVD-RAMs at
$50 or more. Pioneer plans to release a 3.95 G byte commercial DVD-R drive
around July. Toshiba originally claimed DVD-R would be ready in Spring 1997
and DVD-RAM would be available in Fall 1997. Now they say DVD-R will be
available in Summer 1997 and DVD-RAM in 1998. (Don't hold your breath.)
DVD-R/DVD-RAM are not currently designed for home video recording (see
1.14).
----------------------------------------------------------------------------
[5] DVD production
[5.1] How much does it cost to produce a DVD? Isn't DVD much more expensive
than videotape, laserdisc, and CD-ROM?
Videotape, laserdisc, and CD-ROM can't be compared to DVD in a
straightforward manner. There are basically three stages of costs:
production, pre-mastering, and mastering/replication.
DVD production costs are not much higher than for existing media, unless the
extra features of DVD-Video such as multiple sound tracks, camera angles,
etc. are employed.
Pre-mastering costs are proportionately the most expensive part of DVD.
Video and audio must be encoded, menus and control information have to be
authored and encoded, it all has to be multiplexed into a single data
stream, and finally encoded in low level format. Warner's charges for
compression are $120/min for video, $20/min for audio, $6/min for subtitles,
plus formatting and testing at about $30/min. A ballpark estimate for
producing a two-hour DVD movie is about $30,000. If you want to do
pre-mastering yourself, authoring and encoding systems can be purchased from
$100,000 to over $2 million. These prices will drop very rapidly in the next
few years to where DVDs can be produced on desktop computer systems using
additional hardware costing less than $20,000.
Videotapes don't really have a mastering cost, and they run about $2.40 for
replication. CDs cost about $1,000 to master and $0.50 to replicate.
Laserdiscs cost about $3,000 to master and about $8 to replicate. DVDs
currently cost a few thousand dollars to master and about $2.40 to
replicate. Since DVD production is based mostly on the same equipment used
for CD production, mastering and replication costs will quickly drop to CD
levels.
Double-sided or dual-layer discs cost slightly more to replicate, since all
that's required is stamping data on the second substrate (and using
transparent glue for dual layers). Double-sided/dual-layer discs are more
difficult.
[5.2] What DVD authoring systems are available and how much do they cost?
* DVD Creator (encoding) and Scenarist DVD (authoring) by Sonic
Solutions. $180,000 (full cost is about $250,000 with hard disks, DLT
drive, Macintosh PowerPC (for Creator), SGI (for Scenarist), etc.)
<http://www.sonic.com/html/dvd/products_dvd.html>
* Compressionist 250 from Minerva. $99,000. <http://www.minervasys.com>
* ZX-2000 from Zapex Technologies. MPEG-2 video encoding, MPEG/DD audio
encoding.
* Panasonic, JVC, Toshiba, and Pioneer all have authoring systems under
development but nothing available at the moment.
Authoring can also be done by many service bureaus (see below) for around
$300/hour.
[5.3] Who can produce a DVD for me?
* [A] All Post (CA), 818-556-5756.
* [AS] CRUSH Digital Video (NY), <mailto:in...@CrushDV.com> 212-965-1501.
* [A] Digital Video Compression Corporation (CA), <http://www.dvcc.com>
818-777-5185.
* [R] Disc Manufacturing Inc. (AL & CA), <http://www.discmfg.com>
800-433-DISC, 302-479-2525.
* [A] IBM InteractiveMedia (GA), <inter...@vnet.ibm.com> 770-835-7193.
* [R] Imation (formerly 3M) (WI), 612-704-4898.
* [AS] Intel (OR),
<http://developer.intel.com/drg/hybrid_author/devlab.htm> 503-264-3555.
* [R] JVC Disc America (CA), 310-274-2221.
* [AS] KAO Infosystems (CA), <www.kaoinfo.com> 510-657-8425.
* [AR] Kao (ON), 800-871-MPEG.
* [AR] Kao Infosystems (CA), 800-525-6575
* [AR] LaserPacific (CA), <http://www.laserpacific.com> 213-462-6266.
* [R] Metatec (OH), <http://www.metatec.com> 614-761-2000.
* [AS] NB Digital Solutions (MD), <http://www.nbeng.com/dvd.htm>
* [R] Nimbus Manufacturing. 804-985-1100.
* [R] Optical Disc Corporation, 310-946-3050. (LaserWave DirectCut DVD
recorder for creating single copies.)
* Pacific Coast Sound Works (CA), 213-655-4771.
* [A] Pacific Ocean Post Sound (CA), audio only, 310-458-9192.
* [R] Pacific Video Resources (CA), <http://www.pvr.inter.net>
415-864-5679.
* [R] Pioneer Video Manufacturing, Inc.,
<http://www.pioneerusa.com/replication.html> 310-518-0710.
* [AS] Rainmaker (BC), 604-874-8700.
* [A] Sync Sound (NY), 212-246-5580 (5.1 audio).
* [AS] Valkieser Multi Media (Netherlands),
<mailto:newm...@valkieser.nl> 31-35-6955900.
* [ASR] Warner Advanced Media Operations, 717-383-3291.
* [A] Zapex
[A] Authoring (including compression and premastering).
[R] Replication (mastering and/or one-offs).
[S] Use Sonic Solutions' authoring system.
See Robert's DVD Info page <http://www.unik.no/~robert/hifi/dvd/> for more
pointers.
----------------------------------------------------------------------------
[6] Miscellaneous
[6.1] Who invented DVD and who owns it?
DVD is the work of Toshiba, Matsushita, Philips, Sony, and others. There
were originally two next-generation standards for DVD. The MMCD format was
backed Sony, Philips, and others. The competing SD format was backed by
Toshiba, Time Warner, and others. A group of computer companies led by IBM
insisted that the DVD proponents agree on single standard. The combined DVD
format was announced in September of 1995, avoiding a confusing and costly
repeat of the VHS vs. BetaMax videotape battle (or the quadraphonic sound
battle of the 1970s).
No single company "owns" DVD. The DVD Consortium now comprises Hitachi, JVC,
Matsushita, Mitsubishi, Philips, Pioneer, Sony, Thomson, Time Warner, and
Toshiba. (Visit Robert's DVD Info page
<http://www.unik.no/~robert/hifi/dvd/> for links to company Web pages.)
Any company making DVD products must license the technology, partly from a
pool administered by Philips but also separately from Thomson and others.
Matsushita licenses the CSS encryption technology free of charge.
Macrovision licenses its analog anti-recording technology free of charge to
hardware makers, but charges a per-copy royalty to content publishers.
[6.2] Who is making or supporting DVD products?
The following companies have made official statements of products
specifically designed for the DVD format.
Consumer electronics:
* AKAI: DVD-Video player
* Alpine: DVD-ROM-based car navigation system
* Altec Lansing: DVD audio technology
* Clarion: DVD-ROM-based car navigation system
* Denon: DVD-Video player
* Faroudja: DVD-Video player
* Fisher: DVD-Video player
* Hitachi: DVD-Video player
* Hyundai: DVD-Video player
* Innovacom: PC/TV with DVD support
* JVC: DVD-Video players
* LG Electronics (GoldStar): DVD-Video players
* Matsushita (Panasonic/National/Technics/Quasar): DVD-Video players,
DVD-ROM-based car navigation system
* Mitsubishi: DVD-Video players
* NEC: DVD-RAM video camera
* Philips (Magnavox): DVD-Video player
* Pioneer: DVD-Video players
* Samsung: DVD-Video players
* Sharp: DVD-Video player
* Sony: DVD-Video players
* Thomson (RCA/GE/Proscan/Ferguson/Nordmende/Telefunken/Saba/Brandt):
DVD-Video players
* Time Warner (Warner Bros./Turner Broadcasting/HBO/CNN/Warner Music):
DVD-Video players
* Toshiba: DVD-Video players
* Yamaha: DVD-Video player
* Zenith: DVD-Video player
Studios & video publishers:
* Columbia TriStar (Sony)
* Lumivision
* MCA
* MGM
* New Line
* Orion
* Polygram (Philips partner)
* Pony Canyon
* Samsung Entertainment Group
* Toshiba EMI
* Turner
* Universal (Matsushita)
* Victor Entertainment
* Warner Bros. (Toshiba partner)
Computer hardware/software:
* Alliance Semiconductor: DVD-accelerated video controller chips
* Apple: DVD-ROM drives, DVD-ROM-equipped computers, software drivers,
playback hardware and software (QuickTime)
* AST: DVD-ROM-equipped computers (with MMX-based playback software)
* ATI Technologies: DVD-accelerated video audio/video cards
* Axis Communications: DVD-ROM servers
* C-Cube: DVD encoder and decoder chips
* CEI: DVD playback hardware and software
* Cirrus Logic: DVD-accelerated video controller chips
* Compaq: DVD-ROM-equipped computers
* Creative Technology: DVD-accelerated audio/video cards, DVD-ROM upgrade
kits
* Diamond Multimedia: DVD playback hardware (with Toshiba)
* Digital: DVD software playback (for Alpha workstations)
* E4: DVD playback hardware
* Elektroson: DVD-recordable software (top.GEAR)
* Fujitsu: DVD-ROM-equipped computers
* Hitachi: DVD-ROM drives, decoder chips
* Hyundai: DVD decoder chips
* IBM: DVD-ROM-equipped computers, decoder chips
* Innovacom: DVD encoder and decoder chips
* Intel: DVD playback hardware (MMX) and software
* JVC: DVD-ROM drives
* LSI: DVD decoder chips and playback cards
* Matrox: DVD-accelerated video cards
* Matsushita (Panasonic): DVD-ROM drives, DVD/Web integration
* Mediamatics: DVD playback software (w/Microsoft)
* Microsoft: DVD drivers and playback software (ActiveMovie)
* Mitsubishi: DVD-ROM drives
* Motorala: DVD decoder chips
* Number 9: DVD-accelerated audio/video cards
* NEC: DVD-ROM drives
* Oak Technology: DVD playback hardware and software
* Packard Bell: DVD-ROM-equipped computers
* Philips: DVD-ROM drives, decoder chips
* Pioneer: DVD-ROM drives
* S3: DVD-accelerated video controller chips
* Samsung: DVD-ROM drives and DVD-ROM-equipped computers
* SGS-Thomson: DVD playback hardware (w/Microsoft)
* Software Architects: DVD-recordable software (w/Elektroson)
* Sony: DVD-ROM drives and DVD-ROM-equipped computers
* STB Systems: DVD playback hardware
* TDK: blank DVD-RAM discs
* Toshiba: DVD-ROM drives and DVD-ROM-equipped computers
* Trident Microsystems: DVD decoder chips, DVD-accelerated video
controller chips
* Truevision: DVD playback software (Microsoft Active Movie 2.0)
* Wired: DVD playback hardware and software
* Yamaha: AC-3 decoder chips
* Zoran/CompCore: DVD software and hardware playback, DVD decoder chips
Computer software titles on DVD-ROM:
* 2 Way Media: Launch
* Activision: Spycraft: The Great Game, Muppet Treasure Island
* Byron Preiss/Simon & Schuster: The Timetables of Technology
* Creative Multimedia: Billboard Music Guide, Blockbuster Entertainment
Guide to Movies and Video
* Digital Directory Assistance: PhoneDisc PowerFinder USA One
* Discovery Channel
* Discovery Communications: Leopard Son/Animal Planet
* Electronic Arts: Wing Commander IV
* Graphix Zone
* Grolier: Multimedia Encyclopedia
* GT Entertainment: Forrest Gump
* Interactual Technologies: Star Trek VideoSaver
* IVS: The Union Catalogue of Belgian Research Libraries
* Japan Travel Bureau: DVD-Web product
* The Learning Company (SoftKey): Digital Library, The Genius of Edison,
Battles of the World
* Mechadeaus: The Daedalus Encounter
* Multicom: HomeDepot's Home Improvement 1-2-3; Warren Miller's Ski World
'97; Exploring National Parks; Great Chefs, Great Cities; Better Homes
and Gardens Cool Crafts
* Pro CD: Select Phone
* Sega: 4 game/instruction titles to be released in early 1997
* Sumeria: Vanishing Wonders of the Sea
* SuperZero: adult DVD-Video
* Tsunami: Crazy 8's, Silent Steel, Silent Steel II
* Warner Advanced Media
* Westwood Studios: Command & Conquer
* Xiphias: Encyclopedia Electronica
At last count (in Feb 1997), there were 139 registered Internet domain names
with DVD in them. (Thanks to Robert for this interesting tidbit.)
[6.3] Where can I get more information about DVD?
Here are a few of the top DVD info pages. For more extensive pointers go to
Robert's page, which has all the links you will ever need.
* Robert's DVD Info: <http://www.unik.no/~robert/hifi/dvd/>
* Kilroy's DVD FAQs:
<http://www.CD-info.com/CDIC/Technology/DVD/dvd-faq.html> (technical)
and <http://www.icdia.org/dvdfaq02.html> (oriented toward CD-i)
* Chad Fogg's technical notes: <http://www.mpeg.org/~tristan/MPEG/DVD/>
* IMA DVD SIG: <http://www.ima.org/dvd>
* Tristan's MPEG Pointers and Resources <http://www.mpeg.org>
* Compuserve Multimedia Forum, DVD Section (Go MMFORUM)
----------------------------------------------------------------------------
[7] Leftovers
[7.1] What's new in this FAQ?
Recent significant changes (last posted to newsgroups on Feb 16):
Many answers revised.
* Updated answers:
o [1.2] What are the features of DVD-Video? (Feb-16: Identifying
text.)
o [1.3] What's the quality of DVD-Video? Why do some demos look so
bad? (Feb-28: Artifacts from noise reduction. Color problems from
display.)
o [1.5] When will DVD players and drives be available? (Feb-22: More
details of dates, prices, and model numbers. Feb-15: A few new
dates and models. Jan-24: More models. Harman Kardon. Jan-21: More
dates.)
o [1.6] When will DVD titles be available, and how many? (Mar-8:
Lumivision titles, MGM soundtracks. Feb-22: Dates and release
groups for Columbia Tristar. Feb-21: 12 Monkeys in Germany.
Feb-16: Warner music video titles. Feb-5: Warner and Polygram
prices.)
o [1.8] How much do discs cost? (Feb-5: Warner and Polygram prices.)
o [1.9] How quickly will DVD become established? (Reality check for
Toshiba Japan prediction.)
o [1.10] What are "regional codes," "country codes," or "zone
locks"? (Feb-10: Correct regions (I hope!). Thanks Robert. Feb-5:
Revised info on DVD-ROM drives.)
o [1.11] What are the copy protection issues? (Feb-15: More details
on APS and CSS.)
o [1.12] What about DVD-Audio or Music DVD? (Mar-1: More info.)
o [1.14] Will DVD record from VCR/TV/etc? (Jan-26: Obstacles to
recordable DVD, based mostly on a post by Robert.)
o [1.15] What happens if I scratch the disc? Aren't discs too
fragile to be rented? (Jan-12: Sony/Blockbuster deal.)
o [1.19] Is DVD-Video a worldwide standard? Does it work with NTSC,
PAL, and SECAM? (Feb-15: No standards-converting players. Feb-9:
Clarified 24 fps details.)
o [2.9] Will DVD support HDTV TV (DTV/ATV)? (Feb-19: Progressive
scan rumors.)
o [3.1] What are the outputs of a DVD player? (Mar-8: More labels.)
o [3.4] What are the video details? (Mar-8: Progressive scan film
confirmed. Feb-15: MPEG-1 can be VBR. SP@ML supported. More
PAL/NTSC clarification. Max subpicture bit rate.)
o [3.5] How do the aspect ratios work? (Feb-16: More complete
display mode restricton info.)
o [3.6] What are the audio details? (Feb-16: DTS and SDDS details.)
o [3.7] How do the interactive features work? (Mar-8: Brief
description of angles and branching.)
o [4.1] Can I play DVD movies on my computer? (Mar-5:
Region/decryption requirement. Feb-18: QuickTime MPEG.)
o [4.2] What are the features and speeds of DVD-ROM drives? (Mar-5:
Hitachi 2x drive.)
o [5.3] Who can produce a DVD for me? (Feb-24: Valkieser Multi
Media)
o [6.2] Who is making or supporting DVD products? (Feb-16: More.).
[7.2] Remaining unanswered questions
(If you know the answer to any of these, please speak up!)
* What is the exact format of component Y/R-Y/B-Y video output on DVD
players? YPrPb with Rec. 601 scale factors? What's the interface
standard? SMPTE 253M or Betacam or M-II?
* Does the DVD spec allow interleaved VOBs to have different audio or
subpicture streams? I.e., if a Norwegian R-rated movie is only expected
to have its PG version playable in English, can the English soundtrack
be left off the R-rated sections?
* Will Mediamatic's DVD Express playback software play encrypted movies?
* Will regional codes apply to DVD-Audio?
* Are there official designations for 8 cm discs (DVD-1, DVD-2, etc.?)
[7.3] Notation and units
There's an unfortunate confusion of units of measurement in the DVD world.
For example, a single-layer DVD holds 4.7 billion bytes (G bytes), not 4.7
gigabytes (GB). It only holds 4.38 gigabytes. Likewise, a double-sided,
dual-layer DVD holds only 15.90 gigabytes, which is 17 billion bytes.
The problem is that "kilo," "mega," and "giga" generally represent multiples
of 1,000 (10^3, 10^6, and 10^9), but when used in the computer world to
measure bytes they represent multiples of 1,024 (2^10, 2^20, and 2^30).
Most DVD figures are based on 1,000, not 1,024, in spite of using notation
such as GB and KB/s. The closest I have been able to get to an unambiguous
notation is to use kbps for thousands of bits/sec, Mbps for millions of
bits/sec, KB for 1024 bytes, MB for 1,048,576 bytes, and GB for
1,073,741,824 bytes. Feedback on any sort of notation standards would be
helpful.
[7.4] Acknowledgments
This FAQ is written and maintained by Jim Taylor. The following people have
contributed to the FAQ (either directly, by posting to alt.video.dvd, or by
me borrowing from their writing :-). Their contributions are deeply
appreciated. Information has also been taken from material distributed at
the April 1996 DVD Forum.
Robert Lundemo Aas
David Boulet
Espen Braathen
Wayne Bundrick
Roger Dressler
Chad Fogg
Dwayne Fujima
Henrik "Leopold" Herranen
Irek Defee
Kilroy Hughes
Ralph LaBarge
Martin Leese
Dana Parker
Geoffrey Tully
----
This document may be freely redistributed only in its entirety with
authorship notice and acknowledgements intact. No part of it may be sold for
profit or incorporated in a commercial document without the permission of
the copyright holder. Permission is expressly granted for complete
electronic copies to be made available as an archive or mirror service on
the condition that the copy be kept up to date. This document is provided as
is without any express or implied warranty.
[End]
S Hung
Dwayne Fujima
In article <rec-video/dvd-faq_...@rtfm.mit.edu>,
jhta...@videodiscovery.com (Jim Taylor) wrote:
>Projected player releases (1997):
>
> * Japan
> o Akai: January.
DV-P1000 (80,000 yen)
> o Sony: March 21.
DVP-S7000 (110,000 yen)
--
Dwayne Fujima
fuj...@shell2.shore.net