This is the June 16, 2000 revision of the official Internet DVD FAQ for the
rec.video.dvd Usenet newsgroups.
(See below for
what's new.) Please send corrections, additions, and new questions to Jim Taylor
<jtfrog@usa.net>.
This FAQ is updated at least once a month. If you
are looking at a version more than a month old, it's an out-of-date copy. The
most current version is at DVD
Demystified.
Recent changes (last posted to newsgroups on Feb
9):
-
00-06-16: Note explaining how smart discs check regions. (1.10) Since some people don't believe it's possible.
-
00-06-14: A few new predictions and stats. (1.9)
-
00-06-14: Note about verification slowing write speed in
writable drives. (4.2)
-
00-06-13: New questions:
[0.4] How big is this
thing?
[3.4.1] What does
"lines of resolution" mean?
-
00-06-11: A few corrections and additions to Divx section, plus
a link to the Divx Owners Association. (2.10) Thanks RD.
-
00-06-10: New question: [1.45] What's the
difference between Closed Captions and subtitles?
-
00-06-10: Link to Anthony Haukap's FAQ: How To Adjust a TV. (3.2.2)
-
00-06-10: C3D announces 25GB FMDs that could be readable by new
DVD drives. (2.13)
-
00-06-09: Note about Divx the ripper being different from Divx
the defunct. (2.10 and 4.8)
-
00-06-09: Improved explanation of hooking DVD player to an old
TV with RF modulator. (3.2)
- 00-06-06: DVD-Audio buffer holds more than 16 images. (3.6.1) Thanks Jim.
-
00-05-31: New question: [5.10] Where can I get
DVD training?
-
00-05-22: New section: [5.3.4] Other
production services. (Also revised heading for 5.3 and 5.4.)
-
00-05-22: Links to services for transferring video to DVD. (5.8)
-
00-05-22: Link to multipathmovies.com. (1.42)
-
00-05-21: Link to David Lockwood's explanations of aspect
ratios. (3.5)
-
00-05-21: Official Netherlands FAQ mirror location has changed.
(0)
-
00-05-21: Chinese translation available at dvdfaq.126.com.
-
00-05-15: New questions:
[1.6.1] Where can I
read reviews of DVDs?
[1.6.2] How do I
find out when a movie will be available on DVD?
- 00-05-10: Solution for playing Stuart Little on Apex. (1.41) Thanks Steve.
- 00-05-09: Link to the FlikFX Digital Recomposition System. (1.38)
;-)
- 00-05-09: A bit more on stickers on discs. (1.44) Thanks to thread at rec.video.dvd.misc.
- 00-05-05: Software player for parental management no longer available. (1.42)
- 00-05-01: More about confusing measurements, especially data transfer
rates. (7.2)
- 00-04-20: Freeware MPEG-2 encoder: bbMPEG. (5.3)
- 00-04-20: Clarified issue of streaming CSS movies over a network. (4.7)
- 00-04-20: Super Video CD is an option for creating discs playable on DVD
players. (5.7 and
5.8)
- 00-04-20: Link to Jukka Aho's Super Video CD Overview and FAQ. (2.4.6)
- 00-04-20: 4% speedup of movies on PAL VCDs. (2.4.5)
- 00-04-11: New question: [3.2.2] Why is the
audio or video bad?
- 00-04-10: A little more info on DVD production costs. (5.1)
- 00-03-29: Explanation of various physical and application formats. (1.1)
- 00-03-22: Updated licensing info. (6.1)
- 00-03-19: More details on packaging. (1.17)
- 00-03-19: Major rewrite and simplification of player connection info. (3.1 and 3.2)
- 00-03-16: Cine-bit player for PCs can do parental management for any disc.
(1.42)
- 00-03-16: More coax/optical digital audio converters and VGA-YPrPb
converter. (3.1
and 3.2)
- 00-03-15: Going rate for video to DVD-R transfer: $700/hour. (5.8)
- 00-03-13: Link to 7thZone (replacement for DVDUtils)-- lots of DVD
resources. (6.4)
- 00-03-13: Note that Windows CD-ROM drivers work with DVD-ROM drives. (4.1)
- 00-03-13: Link to TenLab NTSC-PAL converters. (1.19)
- 00-03-13: Link to THX overview. (3.6.2)
- 00-03-08: Info about DVD logo trademark. (6.1)
- 00-03-08: Distortion in Saving Private Ryan is intentional. (1.41)
- 00-03-07: Link to Video CD info at CDPage. (2.4.5)
- 00-03-07: Turns out DeCSS wasn't blocked on recent discs. Info removed.
(4.8)
- 00-03-06: Link to The Digital Bits' Ultimate Guide to Anamorphic
Widescreen. (3.5)
- 00-03-01: Updated info on drive speeds. Table of DVD/CD spins and data
rates. (4.2)
Various translations of the DVD FAQ are available:
If you'd like to translate the DVD FAQ into another language (Klingon,
anyone?), please contact Jim.
Yup. Take a gander at Earl's Famous DVD Technology
Exposition Web Page Extravaganza Supreme Deluxe
<lonestar.texas.net/~bdub/earl/dvd.htm>.
Here are a few user
comments on the DVD FAQ. It's the most accurate source of DVD information in
this galaxy. If you find something you think is in error, please let Jim know.
Pointers to other DVD sites are scattered throughout the FAQ and in section
6.4.
Since you asked, here are the stats as of June 13, 2000:
Size: 395 KB (405,404 bytes)
Number of words: 49,856
Number of links:
933
If you're wondering why it's all in one big piece instead of broken into
smaller pieces that would load faster, the main reason is so you can use the
find feature of your browser to easily search the entire FAQ.
DVD, which once stood for Digital Video Disc or Digital Versatile Disc, is
the next generation of optical disc storage technology. It's essentially a
bigger, faster CD that can hold cinema-like video, better-than-CD audio, and
computer data. DVD aims to encompass home entertainment, computers, and business
information with a single digital format, eventually replacing audio CD,
videotape, laserdisc, CD-ROM, and perhaps even video game cartridges. DVD has
widespread support from all major electronics companies, all major computer
hardware companies, and all major movie and music studios. With this
unprecedented support, DVD has become the most successful consumer electronics
product of all time in less than three years of its introduction.
It's important to understand the difference between the physical
formats (such as DVD-ROM or DVD-R) and the application formats (such
as DVD-Video or DVD-Audio). DVD-ROM is the base format that holds data.
DVD-Video (often simply called DVD) defines how video programs are stored on
disc and played in a DVD-Video player or a DVD computer (see 4.1). The difference is
similar to that between CD-ROM and Audio CD. DVD-ROM includes recordable
variations DVD-R, DVD-RAM, DVD-RW, and DVD+RW (see 4.3). The application
formats include DVD-Video, DVD-Video Recording, DVD-Audio (see 1.23), DVD-Audio
Recording, DVD Stream Recording, and SACD). There are also special application
formats for game consoles such as Sony PlayStation II.
- Over 2 hours of high-quality digital video (over 8 on a double-sided,
dual-layer disc).
- Support for widescreen movies on standard or widescreen TVs (4:3 and 16:9
aspect ratios).
- Up to 8 tracks of digital audio (for multiple languages, DVS, etc.), each
with as many as 8 channels.
- Up to 32 subtitle/karaoke tracks.
- Automatic "seamless" branching of video (for multiple story lines or
ratings on one disc).
- Up to 9 camera angles (different viewpoints can be selected during
playback).
- Menus and simple interactive features (for games, quizzes, etc.).
- Multilingual identifying text for title name, album name, song name, cast,
crew, etc.
- Instant rewind and fast forward (no "be kind, rewind" stickers and threats
on rental discs)
- Instant search to title, chapter, music track, and timecode.
- Durable (no wear from playing, only from physical damage).
- Not susceptible to magnetic fields. Resistant to heat.
- Compact size (easy to handle, store, and ship; players can be portable;
replication is cheaper).
- Noncomedogenic.
Note: Most discs do not contain all features (multiple
audio/subtitle tracks, seamless branching, parental control, etc.), as each
feature must be specially authored. Some discs may not allow searching or
skipping.
Most players support a standard set of features:
- Language choice (for automatic selection of video scenes, audio tracks,
subtitle tracks, and menus).*
- Special effects playback: freeze, step, slow, fast, and scan (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 (PCM stereo and Dolby Digital).
- Compatibility with audio CDs.
* Must be supported by additional content on the
disc.
Some players include additional features:
- Component (YUV or RGB) video output for higher-quality picture.
- Progressive-scan component (YUV or RGB) output for highest-quality analog
picture.
- Six-channel analog output from internal audio decoder.
- Recognition and output of DTS Digital Surround audio tracks.
- Compatibility with Video CDs.
- Compatibility with laserdiscs and CDVs.
- Ability to play Divx discs.
- Reverse single frame stepping.
- Reverse play (normal speed).
- RF output (for TVs with no direct video input).
- Multilingual on-screen display.
- Digital zoom (2x or 4x enlargement of a section of the picture). This is a
player feature, not a DVD disc feature.
DVD has the capability to produce near-studio-quality video and
better-than-CD-quality audio. DVD is vastly superior to consumer videotape and
generally better than laserdisc (see 2.8.). However, quality
depends on many production factors. As compression experience and technology
improves we will see increasing quality, but as production costs decrease we
will also see more shoddily produced discs. A few low-budget DVDs will even use
MPEG-1 encoding (which is no better than VHS) instead of higher-quality
MPEG-2.
DVD video is usually encoded from digital studio master tapes to MPEG-2
format. The encoding process uses lossy compression that removes
redundant information (such as areas of the picture that don't change) and
information that's not readily perceptible by the human eye. The resulting
video, especially when it is complex or changing quickly, may sometimes contain
visual flaws, depending on the processing quality and amount of compression. At
average rates of 3.5 Mbps (million bits/second), compression artifacts may be
occasionally noticeable. Higher data rates can result in higher quality, with
almost no perceptible difference from the master at rates above 6 Mbps. As MPEG
compression technology improves, better quality is being achieved at lower
rates.
Video from DVD sometimes contains visible artifacts such as color
banding, blurriness, blockiness, fuzzy dots, shimmering, missing detail, and
even effects such as a face that "floats" behind the rest of the moving picture.
It's important to understand that the term "artifact" refers to anything that
was not originally present in the picture. Artifacts are sometimes caused by
poor MPEG encoding, but artifacts are more often caused by a poorly adjusted TV,
bad cables, electrical interference, sloppy digital noise reduction, improper
picture enhancement, poor film-to-video transfer, film grain, player faults,
disc read errors, etc. Most DVDs exhibit few visible MPEG compression artifacts
on a properly configured system.. If you think otherwise, you are
misinterpreting what you see.
Some early DVD demos were not very good, but this is simply an indication of
how bad DVD can be if not properly processed and correctly reproduced. Many demo
discs were rushed through the encoding process in order to be distributed as
quickly as possible. Contrary to common opinion, and as stupid as it may seem,
these demos were not carefully "tweaked" to show DVD at its best.
In-store demos should be viewed with a grain of salt, since most salespeople are
incapable of properly adjusting a television set.
Most TVs have the sharpness set too high for the clarity of DVD. This
exaggerates high-frequency video and causes distortion, just as the treble
control set too high for a CD causes it to sound harsh. Many DVD players output
video with a black-level setup of 0 IRE (Japanese standard) rather than 7.5 IRE
(US standard). On TVs that are not properly adjusted this can cause some
blotchiness in dark scenes. DVD video has exceptional color fidelity, so muddy
or washed-out colors are almost always a problem in the display (or the original
source), not in the DVD player or disc.
DVD audio quality is superb. DVD includes the option of PCM (pulse code
modulation) digital audio with sampling sizes and rates higher than audio CD.
Alternatively, audio for most movies is stored as discrete, multi-channel
surround sound using Dolby Digital or DTS audio compression similar to the
digital surround sound formats used in theaters. As with video, audio quality
depends on how well the processing and encoding was done. In spite of
compression, Dolby Digital and DTS can be close to or better than CD
quality.
The final assessment of DVD quality is in the hands of consumers. Most
viewers consistently rate it better than laserdisc, but no one can guarantee the
quality of DVD, just as no one should dismiss it based on demos or hearsay. In
the end it's a matter of individual perception and the level of quality
delivered by the playback system.
- It will take years for movies, TV shows, other video programming, and
computer software to become widely available.
- Vagueness of spec and inadequate testing of players and discs has resulted
in incompatibilities. Some movie discs don't function fully (or don't play at
all) on some players.
- It can't record (yet). (See 1.14 and 4.3)
- It has built-in copy protection and regional lockout. (See 1.11 and 1.10)
- It uses digital compression. Poorly compressed audio or video may be
blocky, fuzzy, harsh, or vague. (See 1.3)
- The audio downmix process for stereo/Dolby Surround can reduce dynamic
range. (See 3.6)
- It doesn't fully support HDTV. (See 2.9)
- Some DVD players and drives may not be able to read CD-Rs. (See 2.4.3)
- Current DVD players and drives can't read DVD-RAM discs. (See 4.3)
- Only a few players can play in reverse at normal speed.
- Variations and options such as DVD-Audio, DTS audio tracks, and Divx are
not supported by all players.
Some manufacturers originally announced that DVD players would be available
as early as the middle of 1996. These predictions were woefully optimistic.
Delivery was initially held up for "political" reasons of copy protection
demanded by movie studios, but was later delayed by lack of titles. The first
players appeared in Japan in November, 1996, followed by U.S. players in March,
1997. Players slowly trickled in to other regions. Now, over two years after the
initial launch, over a hundred models of DVD players are available from dozens
of electronics companies. Prices for the first players were $1000 and up. By the
middle of 1999, players were available for under $200 at discount retailers.
See section 6.2
for a list of companies that provide DVD players.
Fujitsu supposedly released the first DVD-ROM-equipped computer on Nov. 6 in
Japan. Toshiba released a DVD-ROM-equipped computer and a DVD-ROM drive in Japan
in early 1997 (moved back from December which was moved back from November).
DVD-ROM drives from Toshiba, Pioneer, Panasonic, Hitachi, and Sony began
appearing in sample quantities as early as January 1997, but none were to be
available before May. The first upgrade kits (combination DVD-ROM drive and
decoder hardware) became available from Creative Labs, Hi-Val, and Diamond
Multimedia in April and May of 1997.
Today, every major PC manufacturer has models that include DVD-ROM drives.
The price difference from the same system with a CD-ROM drive ranges from $30 to
$200 (laptops have more expensive drives). Upgrade kits for older computers are
available for $100 to $700 from Creative
Labs, DynaTek, E4 (Elecede), Hi-Val, Leadtek, Margi Systems (for laptops), Media Forte, Pacific Digital, Sigma Designs, Sony, STB
Systems, Toshiba, Utobia, and others. For more information
about DVDs on computers, including writable DVD drives, see section 4.
Note: If you buy a player or drive from
outside your country (e.g., a Japanese player for use in the US) you may not be
able to play region-locked discs on it. (See 1.10.)
More information:
There are many good players available. Video and audio performance in all
modern DVD players is excellent. Personal preferences, your budget, and your
existing home theater setup all play a large role in what player is best for
you. Unless you have a high-end home theater setup, a player that costs under
$400 should be completely adequate. Make a list of things that are important to
you (such as ability to play CD-Rs, ability to play Video CDs, 96 kHz/24-bit
audio decoding, DTS Digital Out, internal 6-channel Dolby Digital decoder) to
help you come up with a set of players. Then try out a few of the players in
your price range, focusing on ease of use (remote control design, user
interface, front-panel controls). Since there is not a big variation in picture
quality and sound quality within a given price range, convenience features play
a big part. The remote control, which you'll use all the time, can drive you
crazy if it doesn't suit your style.
In certain cases, you might want to buy a DVD PC instead of a standard DVD
player, especially if you want progressive video. See 1.40 and 4.1.
Here are a few questions to ask yourself.
- Do I want selectable sound tracks and subtitles, multiangle viewing, aspect
ratio control, parental/multirating features, fast and slow playback, great
digital video, multichannel digital audio, compatibility with Dolby Pro Logic
receivers, on-screen menus, dual-layer playback, and ability to play audio CDs?
If so, this is the wrong question to ask yourself, since all DVD players have
all of these features.
- Do I appreciate special deals? If so, look for free
DVD coupons and free DVD rentals that are available with many players.
- Do I
want DTS audio? If so, look for a player with the "DTS Digital Out" logo. (See
3.6.2.)
-
Do I want to play Video CDs? If so, check the specs for Video CD compatibility.
(See 2.4.5.)
-
Do I need a headphone jack?
- Do I want player setup menus in languages other
than English? If so, look for multilanguage setup feature. (Note: the
multilanguage menus on certain discs are supported by all players.)
- Do I
want to play homemade CD-R audio discs? If so look for the "dual laser" feature.
(See 2.4.3.)
-
Do I want to replace my CD player? If so, you might want a changer that can hold
3, 5, or even hundreds of discs.
- Do I want to control all my entertainment
devices with one remote control? If so, look for a player with a programmable
universal remote, or make sure your existing universal remote is compatible with
the DVD player.
- Do I want to zoom in to check details of the picture? If
so, look for players with picture zoom.
- Do I want to play HDCDs? If so,
check for the HDCD logo. (See 2.4.13.)
- Does
my receiver have only optical or only coax digital audio inputs? If so, make
sure the player has outputs to match. (See 3.2.)
- Do I care
about black-level adjustment?
For more information, read hardware reviews at Web sites such as DVDFile, DVD Resource, and E-Town, or in magazines such as Widescreen
Review. You may also want to read about user experiences in online forums at Home Theater Forum and DVDFile.
See sections 3.1
and 3.2 for specific
information on what audio/video connections are needed to fit into your existing
setup.
As with hardware, rosy predictions of hundreds of movie titles for Christmas
of 1996 failed to materialize. Only a handful of DVD titles, mostly music
videos, were available in Japan for the November 1996 launch of DVD. Actual
feature films began to appear in December. By April there were over 150 titles
in Japan. Movies appeared in the US in March of 1997. Almost 19,000 discs were
purchased in the first two weeks of the US launch -- more than expected.
InfoTech predicted over 600 titles by the end of 1997 and more than 8,000 titles
by 2000. By December 1997, over 1 million individual DVD discs were shipped. By
June 1999, over 30 million discs had shipped. As of February 2000 there are just
over 6,000 titles available in the US and over 9,000 worldwide. Compared to
other launches (CD, LD, etc.) this is a huge number in a very short time.
See 6.3 for a
list of Web sites where you can buy or rent DVDs.
Availability of DVD hardware and software in Europe runs about a year to 18
months behind the US. A number of launches were announced with little
follow-through, but DVD began to become established around the end of 1998.
For an extensive, searchable database of movie titles available in the US and
Canada see Doug MacLean's DVD List at <www.hometheaterinfo.com/dvdlist.htm>.
Perry Denton has a text list of region 1 titles at <www.surroundfreak.com/dvd/dvd1.htm>.
For titles in Japan and Europe see Niels van Eijkelenburg's list at <www.surroundfreak.com/dvd/dvd2.htm>
(now out of date). Also check out the Internet Movie Database's DVD Browser or the searchable and
downloadable database from the DVD Entertainment Group. There
are also good searchable databases at DVD
File and Express.com.
For a list of widescreen-specific DVD titles, visit http://www.widescreenreview.com/>.
Concorde Video released a PAL-format 12 Monkeys in Germany at the end
of March 1997. They were threatened by Philips with a lawsuit for not including
a multichannel MPEG track, but the issue is now resolved (see 3.6).
DVD-ROM software will slowly appear. Approximately 50% of CD-ROM producers
have announced intentions to develop for DVD-ROM. See 6.2 for a list. Many
initial DVD-ROM titles are only be available as part of a hardware or software
bundle until the market grows larger. IDC expected that over 13 percent of all
software would be available in DVD-ROM format by the end of 1998, but reality
didn't meet expectations. In one sense, DVD-ROMs are simply larger faster
CD-ROMs and will contain the same material. But DVD-ROMs can also take advantage
of the high-quality video and multi-channel audio capabilities being added to
many DVD-ROM-equipped computers.
The following sites have reviews of at least 400 discs. Also see the list of
DVD review
sites at Yahoo.
First, check one of the lists and databases mentioned in 1.6 to make sure it's
not already available. Then check the upcoming release lists at DVD Review and Laser Scans. There's also the
LaserViews DVD
Calendar and release list at Image Entertainment. A good
source of info about unannounced titles is The Digital Bits Rumor Mill.
Mass-market DVD movie players currently list for $300 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, and below $150 by 2005.
DVD-ROM drives and upgrade kits for computers sell for around $80 to $600.
(OEM drive prices are under $70.) Prices are expected to drop quickly to current
CD-ROM drive levels.
It varies, but most DVD movies list for $20 to $30 with street prices between
$15 and $25, even those with supplemental material. Low-priced movies can be
found for under $10. So far DVD has not followed the initial high rental price
model of VHS.
DVD-ROMs will initially be slightly more expensive than CD-ROMs since there
is more on them, they cost more to replicate, and the market is smaller. But
once production costs drop and the installed base of drives grow, DVD-ROMs will
cost about the same as CD-ROMs today.
Not as fast as some early predictions, but faster than videotape, laserdisc,
and CD. Before it's third birthday in March 2000, DVD had become the most
successful consumer electronics product ever.
Here are some predictions:
- Toshiba (1996): 100,000 to 150,000 DVD-Video players will be sold in Japan
between Nov. 1 and Dec. 31, 1996, and 750,000-1 million by Nov. 1, 1997.
(Actual count of combined shipments by Matsushita, Pioneer, and Toshiba was
70,000 in Oct-Dec 1996.)
- Pioneer (1996): 400,000 DVD-Video players in 1996, 11 million by 2000.
100,000 DVD-Audio players in 1996, 4 million by 2000.
- InfoTech (1996): 820,000 DVD-Video players in first year, 80 million by
2005.
- CEMA (1997): 400,000 DVD-Video players in U.S. in 1997, 1 million in 1998.
- Time-Warner (1996): 10 million DVD players in the U.S. by 2002.
- Paul Kagan (1997): 800,000 DVD players in the U.S. in 1997, 10 million in
2000, and 40 million in 2006 (43% penetration). 5.6 million discs sold in
1997, 172 million discs in 2000, and 623 million in 2006.
- C-Cube (1996): 1 million players and drives in 1997.
- BASES: 3 million DVD-Video players sold in first year, 13 million sold in
6th year.
- Dataquest (1997): over 33 million shipments of DVD players and drives by
2000.
- Philips (1996): 25 million DVD-ROM drives worldwide by 2000 (10% of
projected 250 million optical drives).
- Pioneer (1996): 500,000 DVD-ROM drives sold in 1997, 54 million sold in
2000.
- Toshiba (1996): 120 million DVD-ROM drives in 2000 (80% penetration of 100
million PCs). Toshiba says they will no longer make CD-ROM drives in 2000.
- IDC (1997): 10 million DVD-ROM drives sold in 1997, 70 million sold in
2000 (surpassing CD-ROM), 118 million sold in 2001. Over 13% of all software
available on DVD-ROM in 1998. DVD recordable drives more than 90% of combined
CD/DVD recordable market in 2001.
- AMI (1997): installed base of 7 million DVD-ROM drives by 2000.
- Intel (1997): 70 million DVD-ROM drives by 1999 (sales will surpass CD-ROM
drives in 1998).
- SMD (1997): 100 million DVD-ROM/RAM drives shipped in 2000.
- Microsoft (Peter Biddle, 1997): 15 million DVD PCs sold in 1998, 50
million DVD PCs sold in 1999.
- Microsoft (Jim Taylor, 1998): installed base of 35 million DVD PCs in
1999.
- Forrester Research (1997): U.S. base of 53 million DVD-equipped PCs by
2002. 5.2% of U.S. households (5 million) will have a DVD-V player in 2002; 2%
will have a DVD-Audio player.
- Yankee Group (Jan 1998): 650,000 DVD-Video players by 1998, 3.6 million by
2001. 19 million DVD-PCs by 2001.
- InfoTech (Jan 1998): 20 million DVD-Video players worldwide in 2002, 58
million by 2005. 99 million DVD-ROM drives worldwide in 2005. No more than 500
DVD-ROM titles available by the end of 1998. About 80,000 DVD-ROM titles
available by 2005.
- Screen Digest (Dec 1998): 125,000 DVD-Video player in European homes in
1998, 485,000 in 1999, 1 million in 2000.
- IRMA (Apr 2000): 12 million players will ship worldwide in 2000.
- Baskerville (Apr 2000): Worldwide spending on DVD software will surpass
that of VHS by 2003. There will be a worldwide installed based of 625 million
DVD players by 2010 (55% of TV households).
- Jon Peddie (Jun 2000): Almost 20 million DVD players will be sold in the
U.S. in 2004.
Here's reality:
- 1997
- 349,000 DVD-Video players shipped in the U.S. (About 200,000 sold into
homes.)
- 900 DVD-Video titles available in the U.S. Over 5 million copies
shipped; about 2 million sold.
- Over 500,000 DVD-Video players shipped worldwide.
- Around 330,000 DVD-ROM drives shipped worldwide with about 1 million
bundled DVD-ROM titles.
- 60 DVD-ROM titles (mostly bundled).
- 1998
- 1,089,000 DVD-Video players shipped in the U.S. (Installed base of
1,438,000.)
- 400 DVD-Video titles in Europe (135 movie and music titles).
- 3,000 DVD-Video titles in the U.S. (2000 movie and music titles).
- 7.2 million DVD-Video discs purchased.
- 1999
- 4,019,000 DVD-Video players shipped in the U.S. (Installed base of
5,457,000.)
- Over 6,300 DVD-Video titles in the U.S.
- About 26 million DVD-ROM drives worldwide.
- About 75 DVD-ROM titles available in the U.S.
- 2000 (as of June)
- Over 2 million DVD-Video players shipped in the U.S. (Installed base of
7,470,000.)
- About 34 million DVD-ROM drives worldwide.
- Over 9,000 DVD-Video titles available in the U.S.
(For latest U.S. player sales statistics, see the CEA page at
The Digital Bits.)
For comparison, there were about 700 million audio CD players and 160 million
CD-ROM drives worldwide in 1997. 1.2 billion CD-ROMs were shipped worldwide in
1997 from a base of about 46,000 different titles. There were about 80 million
VCRs in the U.S. (89% of households) and about 400 million worldwide. 110,000
VCRs shipped in the first two years after release. Nearly 16 million VCRs were
shipped in 1998. There are about 3 million laserdisc players in the U.S. There
are about 270 million TVs in the U.S. and 1.3 billion worldwide.
Motion picture studios want to control the home release of movies in
different countries because theater releases aren't simultaneous (a movie may
come out on video in the U.S. when it's just hitting screens in Europe). Also,
studios sell distribution rights to different foreign distributors and would
like to guarantee an exclusive market. Therefore they have required that the DVD
standard include codes that can be used to prevent playback of certain discs in
certain geographical regions. Each player is given a code for the region in
which it's sold. The player will refuse to play discs that are not allowed in
that region. This means that discs bought in one country may not play on players
bought in another country. Some people believe that region codes could be
considered an illegal restraint of trade, but there have been no legal cases to
establish this.
Regional codes are entirely optional for the maker of a disc. Discs without
codes will play on any player in any country. It's not an encryption system,
it's just one byte of information on the disc that the player checks. Some
studios originally announced that only their new releases will have regional
codes, but so far almost all releases play in only one region. Region codes are
a permanent part of the disc, they won't "unlock" after a period of time.
There are 8 regions (also called "locales"). Players and discs are identified
by the region number superimposed on a world globe. If a disc plays in more than
one region it will have more than one number on the globe.
1: U.S., Canada,
U.S. Territories
2: Japan, Europe, South Africa, and Middle East (including
Egypt)
3: Southeast Asia and East Asia (including Hong Kong)
4: Australia,
New Zealand, Pacific Islands, Central America, Mexico, South America, and the
Caribbean
5: Eastern Europe (Former Soviet Union), Indian subcontinent,
Africa, North Korea, and Mongolia
6: China
7: Reserved
8: Special
international venues (airplanes, cruise ships, etc.)
(See the map at <www.unik.no/~robert/hifi/dvd/world.html>.)
There is no such thing as a region 0 disc. There is such thing as an
all-region disc. There are region 0 players (see next paragraph).
Some players can be modified to play discs regardless of their regional
codes. This usually voids the warranty, but is probably not illegal. (The only
thing that requires player manufacturers to make region-coded players is the CSS
license. See 1.11)
Some discs from Fox, Buena Vista/Touchstone/Miramax, MGM/Universal, and Polygram
contain program code that checks for the proper region. (There's Something
About Mary is a recent example.) These "smart discs" that do active region
checking won't play on code-free players that have their region set to 0,
but they can be played on manual code-switchable players that allow you
to change the region using the remote control. They may not work on
auto-switching players that recognize and match the disc region. (It
depends on the default region setting of the player. A disc can have all its
region flags set so that the player doesn't know which one to switch to, then it
can query the player for the region setting and abort if it's the wrong one. A
default setting of region 1 will fool smart discs from region 1.) Information
about modifying players can be found on the Internet (at sites such as Code Free DVD, dvdkits.com, DVD Upgrades, Link Electronics, PlanetDVD, 7thZone, Techtronics, Upgrade Heaven, and <www.brouhaha.com/~eric/video/dvd/>)
and in the rec.video.dvd newsgroups (searchable at Deja.com).
Regional codes also apply to DVD-ROM systems, but used only with DVD-Video
discs, not DVD-ROM discs containing computer software. (See 1.11 below for more
details). Computer playback systems check for regional codes before playing
movies from a DVD-Video. Newer "RPC2" DVD-ROM drives let you change the region
code several times. Once a drive has reached the limit (usually 5 changes) it
can't be changed again unless the vendor or manufacturer resets it. The Drive
Info utility can tell you if you have an RPC2 drive (it will say "This drive has
region protection"). Drive Info and information about circumventing DVD-ROM
region restrictions is available from Internet sites such as Visual Domain and DVD Infomatrix. After December 31, 1999,
only RPC Phase II drives will be manufactured.
Regional codes do not apply to DVD-Audio.
There are four forms of copy protection used by DVD:
1) Analog CPS (Macrovision)
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. Macrovision adds a rapidly modulated colorburst signal
("Colorstripe") along with pulses in the vertical blanking signal ("AGC") to the
composite video and s-video outputs. This confuses the synchronization and
automatic-recording-level circuitry in 95% of consumer VCRs. Unfortunately, it
can degrade the picture, especially with old or nonstandard equipment.
Macrovision may show up as stripes of color, distortion, rolling, black &
white picture, and dark/light cycling. Macrovision creates problems for many
line doublers. Macrovision is not present on analog component video output of
early players, but is required on newer players (AGC only, since there is no
burst in a component signal). The discs contain "trigger bits" telling the
player whether or not to enable Macrovision AGC, with the optional addition of
2-line or 4-line Colorstripe. The triggers occur about once a second, which
allows fine control over what part of the video is protected. The producer of
the disc decides what amount of copy protection to enable and then pays
Macrovision royalties accordingly (a few cents per disc). Just as with
videotapes, some DVDs are Macrovision-protected and some aren't. (For a few
Macrovision details see STMicroelectronics' NTSC/PAL video encoder datasheets at
<www.st.com/stonline/books/>.)
2) CGMS
Each disc also contains information specifying if
the contents can be copied. This is a "serial" copy generation management system
(SCMS) designed to prevent copies or copies of copies. The CGMS information is
embedded in the outgoing video signal. For CGMS to work, the equipment making
the copy must recognize and respect the CGMS. The analog standard (CGMS/A)
encodes the data on NTSC line 21 (in the XDS service). The digital standard
(CGMS/D) is not yet finalized, but will apply to digital connections such as IEEE 1394/FireWire. See section 4, below.
3) Content Scrambling System (CSS)
Because of the
potential for perfect digital copies, paranoid movie studios forced a deeper
copy protection requirement into the DVD standard. Content Scrambling System
(CSS) is a data encryption and authentication scheme intended to prevent copying
video files directly from the disc. CSS was developed primarily by Matsushita
and Toshiba. Each CSS licensee is given a key from a master set of 400 keys that
are stored on every CSS-encrypted disc. This allows a license to be revoked by
removing its key from future discs. The CSS decryption algorithm exchanges keys
with the drive unit to generate an encryption key that is then used to obfuscate
the exchange of disc keys and title keys that are needed to decrypt data from
the disc. DVD players have CSS circuitry that decrypts the data before it's
decoded and displayed. On the computer side, DVD decoder hardware and software
must include a CSS decryption module. All DVD-ROM drives have extra firmware to
exchange authentication and decryption keys with the CSS module in the computer.
Beginning in 2000, new DVD-ROM drives are required to support regional
management in conjunction with CSS (see 1.10 and 4.1). Makers of
equipment used to display DVD-Video (drives, decoder chips, decoder software,
display adapters, etc.) must license CSS. There is no charge for a CSS license,
but it's a lengthy process, so it's recommended that interested parties apply as
soon as possible. Near the end of May 1997, CSS licenses were finally granted
for software decoding. The license is extremely restrictive in an attempt to
keep the CSS algorithm and keys secret. Of course, nothing that's used on
millions of players and drives worldwide could be kept secret for long. In
October 1999, the CSS algorithm was cracked and posted on the Internet,
triggering endless controversies and legal battles (see 4.8).
4) Digital Copy Protection System (DCPS)
In order to
provide for digital connections between components without allowing perfect
digital copies, five digital copy protection systems have been proposed to CEMA. The frontrunner is DTCP (digital transmission content protection),
which focuses on IEEE 1394/FireWire but can be applied to other protocols. The
draft proposal (called 5C, for the five companies that developed it) was made by
Intel, Sony, Hitachi, Matsushita, and Toshiba in February 1998. Sony released a
DTCP chip in mid 1999. Under DTCP, devices that are digitally connected, such as
a DVD player and a digital TV or a digital VCR, exchange keys and authentication
certificates to establish a secure channel. The DVD player encrypts the encoded
audio/video signal as it sends it to the receiving device, which must decrypt
it. This keeps other connected but unauthenticated devices from stealing the
signal. No encryption is needed for content that is not copy protected. Security
can be "renewed" by new content (such as new discs or new broadcasts) and new
devices that carry updated keys and revocation lists (to identify unauthorized
or compromised devices). A competing proposal, XCA (extended conditional
access), from Zenith and Thomson, is similar to DTCP but can work with one-way
digital interfaces (such as the EIA-762 RF remodulator standard) and uses smart
cards for renewable security. Other proposals have been made by MRJ Technology,
NDS, and Philips. In all five proposals, content is marked with CGMS-style flags
of "copy freely", "copy once," "don't copy," and sometimes "no more copies".
Digital devices that do nothing more than reproduce audio and video will be able
to receive all data (as long as they can authenticate that they are playback-
only devices). Digital recording devices are only able to receive data that is
marked as copyable, and they must change the flag to "don't copy" or "no more
copies" if the source is marked "copy once." Digital CPS is designed for the
next generation of digital TVs, digital receivers, and digital video recorders.
It will require new DVD players with digital connectors (such as those on DV
equipment). These new products won't appear until 2000. Since the encryption is
done by the player, no changes are needed to the existing disc format.
The first 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. DCPS is performed by the DVD player, not by the
disc developer.
These copy protection schemes are designed only to guard against casual
copying (which the studios claim causes billions of dollars in lost revenue).
The goal is to "keep the honest people honest." Even the people who developed
the copy protection standards admit that they won't stop well-equipped pirates.
There are inexpensive devices that defeat Macrovision, although only a few work
with the new Colorstripe feature. These devices go under names such as Video
Clarifier, Image Stabilizer, Color Corrector, and CopyMaster.
Movie studios have promoted legislation making it illegal to defeat DVD copy
protection. The result is the World Intellectual
Property Organization (WIPO) Copyright Treaty and the WIPO Performances and
Phonograms Treaty (December 1996) and the compliant U.S. Digital Millennium Copyright Act (DMCA), passed
into law in October 1998. Software intended specifically to circumvent copy
protection is now illegal in the U.S. and many other countries. A co-chair of
the legal group of the DVD copy protection committee stated, "in the video
context, the contemplated legislation should also provide some specific
assurances that certain reasonable and customary home recording practices will
be permitted, in addition to providing penalties for circumvention." It's not at
all clear how this might be "permitted" by a player or by studios that set the
"don't copy" flag on all their discs.
DVD-ROM drives and computers, including DVD-ROM upgrade kits, are required to
support Macrovision, CGMS, and CSS. PC video cards with TV outputs that don't
support Macrovision will not work with encrypted movies. Computers with IEEE
1394/FireWire connections must support the final DCPS standard in order to work
with other DCPS devices. Every DVD-ROM drive must include CSS circuitry to
establish a secure connection to the decoder hardware or software in the
computer, although CSS can only be used on DVD-Video content. Of course, since a
DVD-ROM can hold any form of computer data, other encryption schemes can be
implemented. See 4.1
for more information on DVD-ROM drives.
The Watermarking Review Panel (WaRP) --the successor to the Data-Hiding
Sub-Group (DHSG)-- of the industry's Copy Protection Technical Working Group
(CPTWG) is evaluating watermarking proposals. The original seven watermarking
proposals that were merged into three: IBM/NEC, Hitachi/Pioneer/Sony, and
Macrovision/Digimarc/Philips. On February 17, 1999, the first two groups
combined to form the "Galaxy Group" and merged their technologies into a single
proposal. The second group has dubbed their technology "Millennium."
Watermarking, which is used for DVD-Audio and will be added to DVD-Video at some
point, permanently marks each digital audio or video frame with noise that is
supposedly undetectable by human ears or eyes. Watermark signatures can be
recognized by playback and recording equipment to prevent copying, even when the
signal is transmitted via digital or analog connections or is subjected to video
processing. New players and other equipment will be required to support
watermarking, but the DVD Forum intends to make watermarked discs compatible
with existing players. There were reports that the early watermarking technique
used by Divx caused visible "raindrop" or "gunshot" patterns, but the problem
seemed to have been solved for later releases.
When DVD was released in 1996 there was no DVD-Audio format, although the
audio capabilities of DVD-Video far surpassed CD. The DVD Forum sought
additional input from the music industry before defining the DVD-Audio format. A
draft standard was released by the DVD Forum's Working Group 4 (WG4) in January
1998, and version 0.9 was released in July. The final DVD-Audio 1.0
specification (minus copy protection) was approved in February 1999 and released
in March, but products were delayed in part by the slow process of selecting
copy protection features (encryption and watermarking), with complications
introduced by the Secure Digital Music Initiative (SDMI). The scheduled October
1999 release was further delayed until mid 2000, ostensibly because of concerns
caused by the CSS crack (see 4.8), but also because
the hardware wasn't quite ready, production tools aren't up to snuff, and there
is lackluster support from music labels. Pioneer released DVD-Audio players in
Japan in late 1999, but they won't play copy-protected discs.
Matsushita hopes to have Panasonic and Technics brand universal
DVD-Audio/DVD-Video players available in July 2000 for $700 to $1,200. Pioneer,
JVC, Yamaha, and others may also release DVD-Audio players at the same time.
However, there seem to be almost no DVD-Audio titles to play on the new
players.
In the meantime, the DVD-Video standard includes surround sound audio and
better-than-CD audio (see 3.6.2).
DVD-Audio is a separate format from DVD-Video. DVD-Audio discs can be
designed to work in DVD-Video players, but it's possible to make a DVD-Audio
disc that won't play at all in a DVD-Video player, since the DVD-Audio
specification includes new formats and features, with content stored in a
separate "DVD-Audio zone" on the disc (the AUDIO_TS directory) that DVD-Video
players never look at. New DVD-Audio players are needed, or new "universal
players" that can play both DVD-Video and DVD-Audio discs.
Plea to producers: Universal players won't
be available for some time, but you can make universal discs today. With
a small amount of effort, all DVD-Audio discs can be made to work on all DVD
players by including a Dolby Digital version of the audio in the DVD-Video
zone.
Plea to DVD-Audio authoring system
developers: Make your software do this by default or strongly
recommend this option during authoring.
DVD-Audio (and universal) players will work with existing receivers. They
output PCM and Dolby Digital, and some will support the optional DTS and DSD
formats. However, most current receivers can't decode the high-definition,
multichannel PCM audio (see 3.6.1 for details),
and even if they could it can't be carried on standard digital audio
connections. DVD-Audio players with high-end digital-to-analog converters (DACs)
can only be hooked up to receivers with two-channel or 6-channel analog inputs,
but some quality will be lost if the receiver converts back to digital for
processing. Future receivers with improved digital connections such as IEEE 1394
(FireWire) will be needed to use the full digital resolution of DVD-Audio.
DVD audio is copyright protected by an embedded signaling or
digital watermark feature. This uses signal processing technology to
apply a digital signature and optional encryption keys to the audio in the form
of supposedly inaudible noise so that new equipment will recognize copied audio
and refuse to play it. Audiophiles claim this degrades the audio, but tests
performed by the 4C indicate that even golden-eared listeners can't detect the
watermarking noise. Proposals from Aris, Blue Spike, Cognicity, IBM, and Solana
were evaluated by major music companies in conjunction with the 4C Entity,
comprising IBM, Intel, Matsushita, and Toshiba. Aris and Solana merged to form a
new company called Verance, whose Galaxy technology was chosen for
DVD-Audio in August 1999. (In November 1999, Verance watermarking was also
selected for SDMI.)
Sony and Philips have developed a competing Super Audio CD format that uses
DVD discs. (See 3.6.1 for details.)
SACD is supposed to provide "legacy" discs that have two layers, one that plays
in existing CD players, plus a high-density layer for DVD-Audio players, but
technical difficulties have kept dual-format discs from being produced.
Ironically, initial price for these dual-layer discs will be higher than for a
standard CD plus a standard DVD. Sony released version 0.9 of the SACD spec in
April 1998, the final version appeared in April (?) 1999. SACD technology is
available to existing Sony/Philips CD licensees at no additional
cost. Pioneer, which released the first DVD-Audio players in Japan at the
end of 1999, included SACD support in their DVD-Audio players. If other
manufacturers follow suit, the entire SACD vs. DVD-Audio standards debate will
be moot, since DVD-Audio players will play both types of discs.
Sony released an SACD player in Japan in May 1999 at the tear-inducing price
of $5,000. The player was released in limited quantities in the U.S. at the end
of 1999. New lower cost SACD players will be available by fall 2000. Initial
SACD releases are mixed in stereo, not multichannel. About 40 SACD titles were
available at the end of 1999, from studios such as DMP, Mobile Fidelity Labs,
Pioneer, Sony, and Telarc.
All major movie studios, most major music studios.
When DVD players became available in early 1997, Warner and Polygram were the
only major movie studios to release titles. Additional titles were available
from small publishers. The other studios gradually joined the DVD camp (see 6.2 for a full list,
see 1.6 for movie
info). Dreamworks was the last significant studio to announce full DVD support.
Paramount, Fox, and Dreamworks initially supported only Divx, but in summer 1998
they each announced support for open DVD.
Short Answer: Not yet, but soon. Most of the major DVD player manufactureres
have announced DVD home video recorders. (See 4.3.)
Long answer: Recording analog video to DVD is a very tricky process. 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. It's difficult in real time to encode the video
and audio, combine them with DVD-Video info, and write the whole thing to a
recordable DVD disc, especially in a form that's compatible with standard
DVD-Video players. This is still extremely expensive for a home recorder, even
though prices for DVD production systems have dropped over the space of three
years from millions of dollars to thousands of dollars to hundreds of dollars
for the simplest packages.
Other obstacles: Blank discs cost about $25 (although they will get cheaper
over time). Real-time compression requires higher bit rates for decent quality,
thus lowering capacity. 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 special prefilters, which increases the cost).
Don't be confused by DVD-R drives, DVD-RAM drives, or other recordable DVD
drives for computers (see 4.3). These existing
recorders can store data, but to create full-featured DVD-Videos requires
additional hardware and software to do video encoding (MPEG), audio encoding
(Dolby Digital, MPEG, or PCM), subpicture encoding (run-length-compressed
bitmaps), still frame encoding (MPEG), navigation and control data generation,
and multiplexing.
In spite of all the difficulties, many of the major DVD manufacturers are
working on recordable DVD for the home. We will see various DVD video recorders
in the year 2000. Early units, especially those that can record from analog
video sources such as TV, will be expensive: probably $2,000 and up. There will
also be cheaper units that can record only from a source of already-compressed
digital audio and video, such as satellite, DTV, or digital cable. At some
point, DVD recorder/players will be built into satellite and cable
receivers.
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. Once the encoding
technology is fast and cheap enough, and blank discs are cheap enough,
recordable DVD will reach the mainstream.
Most scratches will cause minor channel data errors that are easily
corrected. That is, data is stored on DVDs using powerful error correction
techniques that can recover from scratches as big as 6 millimeters with no loss
of data. A common misperception is that a scratch will be worse on a DVD than on
a CD because of higher storage density and because video is heavily compressed.
DVD data density (say that fast ten times!) is physically four times that of
CD-ROM, so it's true that a scratch will affect more data. But DVD error
correction is at least ten times better than CD-ROM error correction and more
than makes up for the density increase. It's also important to realize that
MPEG-2 and Dolby Digital compression are partly based on removal or reduction of
imperceptible information, so decompression doesn't expand the data as much as
might be assumed. Major scratches may cause uncorrectable errors that will
produce an I/O error on a computer or show up as a momentary glitch in DVD-Video
picture. Paradoxically, sometimes the smallest scratches can cause the worst
errors (because of the particular orientation and refraction of the scratch).
There are many schemes for concealing errors in MPEG video, which may be used in
future players.
See 1.39 for
information on care and cleaning of DVDs.
The DVD computer advisory group specifically requested no mandatory caddies
or other protective carriers. Consider that laserdiscs, music CDs, and CD-ROMs
are likewise subject to scratches, but many video stores and libraries rent
them. Major chains such as Blockbuster and West Coast Entertainment rent DVDs in
many locations. So far most reports of rental disc performance are positive. A
nice list of DVD rental outlets is at <home.earthlink.net/~tlfordham/rental.html>.
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.
Manufacturers are worried about customers assuming DVDs will play in their CD
player, so they would like the packaging to be different. There are a number of
DVD packages that are as wide as a CD jewel box (about 5-5/8") and as tall as a
VHS cassette box (about 7-3/8"), as recommended by the Video Software Dealers
Association (VSDA). However, no one is being forced to use a larger package
size. Some companies use standard jewel cases or paper and vinyl sleeves. Divx
discs came in paperboard and plastic Q-Pack cases the same size as a CD jewel
case.
Most movies are packaged in the Amaray "keep case," an all-plastic clamshell
with clear vinyl pockets for inserts, that's popular among consumers. Time
Warner's "snapper," a paperboard case with a plastic lip, is less popular.
There's also a "super jewel box," the stretch-limo version of a CD jewel case,
that's common in Europe.
A dual-layer disc has two layers of data, one of them semi-transparent so
that the laser can focus through it and read the second layer. Since both layers
are read from the same side, a dual-layer disc can hold almost twice as much as
a single-layer disc, for over 4 hours of video (see 3.3 for more details).
Many discs use dual layers. Initially only a few replication plants could make
dual-layer discs, but most plants now have the capability. The second layer can
use either a PTP (parallel track path) layout where both tracks run in parallel
(for independent data or special switching effects), or an OTP (opposite track
path) layout where the second track runs in an opposite spiral; that is, the
pickup head reads out from the center on the first track then in from the
outside on the second track. The OTP layout is designed to provide continuous
video across both layers. The layer change can occur anywhere in the video; it
doesn't have to be at a chapter point. There's no guarantee that the switch
between layers will be seamless. The layer change is invisible on some players,
but it can cause the video to freeze for a fraction of a second or up to 4
seconds on other players. The "seamlessness" depends as much on the way the disc
is prepared as on the design of the player. OTP is also called RSDL
(reverse-spiral dual layer). The advantage of OTP/RSDL is that long movies can
use higher data rates for better quality than with a single layer. See 1.27 for layer change
details.
There are various ways to recognize dual-layer discs: 1) the gold color, 2) a
menu on the disc for selecting the widescreen or letterbox version, 3) two
serial numbers on one side.
All DVD players and drives can read dual-layer discs -- it's required
by the spec. All players and drives also play double-sided discs if you flip
them over. No manufacturer has announced a model that will play both sides. The
added cost is probably not justifiable since discs can hold over 4 hours of
video on one side by using two layers. (Early discs used two sides because
dual-layer production was not widely supported. This should no longer be a
problem.) Pioneer LD/DVD players can play both sides of an LD, but not a DVD.
(See 2.12 for note
on reading both sides simultaneously.)
DVD has the same NTSC vs. PAL problem as videotape and laserdisc. The MPEG
video on DVD is stored in digital format, but it's formatted for one of two
mutually incompatible television systems: 525/60 (NTSC) or 625/50 (PAL/SECAM).
There are three differences between discs intended for playback on different
systems: picture size and pixel aspect ratio (720x480 vs. 720x576), display
frame rate (29.97 vs. 25), and surround audio (Dolby Digital vs. MPEG). (See 3.4 and 3.6 for details.) Video
from film is usually encoded at 24 frames/sec but is preformatted for one of the
two display rates. Movies formatted for PAL display are usually sped up by 4%,
so the audio must be adjusted accordingly before being encoded. All PAL DVD
players can play Dolby Digital audio tracks, but not all NTSC players can play
MPEG audio tracks. PAL and SECAM share the same scanning format, so discs are
the same for both systems. The only difference is that SECAM players output the
color signal in the format required for SECAM TVs.
Some players only play NTSC discs, some players only play PAL discs, and some
play both. All DVD players sold in PAL countries play both. These
multi-standard players partially convert NTSC to a 60Hz PAL (4.43 NTSC)
signal. The player uses the PAL 4.43 MHz color subcarrier encoding format but
keeps the 525/60 NTSC scanning rate. Most modern PAL TVs can handle this kind of
"pseudo-PAL" 60-Hz signal. A few multi-standard PAL players output true 3.58
NTSC from 525/60 NTSC discs, which requires an NTSC TV or a multi-standard TV.
Some players have a switch to choose 60-Hz PAL or NTSC output when playing NTSC
discs. There are a few standards-converting PAL players (from Samsung and
others) that convert from a 525/60 NTSC disc to standard PAL output. Proper
standards conversion requires expensive hardware to handle scaling, temporal
conversion, and object motion analysis. Because the quality of conversion in DVD
players is poor, using 60Hz PAL output with a compatible TV provides a better
picture. Most NTSC players can't play PAL discs. A very small number of NTSC
players (such as the Apex) can convert 625/50 PAL to NTSC. External converter
boxes are also available, such as the Emerson EVC1595 ($350). High-quality
converters are available at TenLab.
A producer can choose to put 525/60 video on one side of the disc and 625/50
on the other. Most studios so far are including Dolby Digital audio tracks on
their PAL discs.
There are actually three types of DVD players if you count computers. Most
DVD PC software and hardware can play both NTSC and PAL video and both Dolby
Digital and MPEG audio. Some PCs can only display the converted video on the
computer monitor, but others can output it as a video signal for a TV.
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.
Even though DVD's dual-layer technology (see 3.3) allows over four
hours of continuous playback from a single side, some movies are split over two
sides of a disc, requiring that the disc be flipped partway through. Most
"flipper" discs exist because of producers who are too lazy to optimize the
compression or make a dual-layer disc. Better picture quality is a cheap excuse
for increasing the data rate; in many cases the video will look better if
carefully encoded at a lower bit rate. Lack of dual-layer production capability
is also a lame excuse; in 1997 very few DVD plants could make dual-layer discs,
but this is no longer the case. No players can automatically switch sides, but
it's not needed since most movies less than 4 hours long can easily fit on one
dual-layer (RSDL) side.
There is a list of "flipper" discs in the Film Vault at DVD
Review. Note: A flipper is not the same as a disc with a widescreen version on
one side and a pan & scan version or supplements on the other. Please send
additions to info@dvdreview.com. (The
list has gotten too long to keep in this FAQ.)
Answer: RTFM. You are watching an anamorphic picture intended for display
only on a widescreen TV. (See 3.5 for technical
details). You need to go into the player's setup menu and tell it you have a
standard 4:3 TV, not a widescreen 16:9 TV. It will then automatically letterbox
the picture so you can see the full width at the proper proportions.
In some cases you can change the aspect ratio as the disc is playing (by
pressing the "aspect" button on the remote control). On most players you have to
stop the disc before you can change aspect. Some discs are labeled with
widescreen on one side and standard on the other. In order to watch the
fullscreen version you must flip the disc over.
See Steve Tannehill's Why Does The Picture
Look Squished? article for further explanation and pictures.
Most DVD-Video discs contain Dolby Digital soundtracks. However, it's not
required. Some discs, especially those containing only audio, have PCM tracks.
It's also possible for a 625/50 (PAL) disc to contain only MPEG audio, but so
far MPEG audio is not widely used.
Don't assume that the "Dolby Digital" label is a guarantee of 5.1 channels. A
Dolby Digital soundtrack can be mono, dual mono, stereo, Dolby Surround stereo,
etc. For example, Blazing Saddles and Caddyshack are mono movies, so the Dolby
Digital soundtrack on these DVDs has only one channel. Some DVD packaging has
small lettering or icons under the Dolby Digital logo that indicates the channel
configuration. In some cases, there is more than one Dolby Digital version of a
soundtrack: a 5.1-channel track and a track specially remixed for stereo Dolby
Surround. It's perfectly normal for your DVD player to indicate playback of a
Dolby Digital audio track while your receiver indicates Dolby Surround: it means
that the disc contains a two-channel Dolby Surround signal encoded in Dolby
Digital format.
See 3.6 for more
audio details.
Laserdiscs are subject to what's commonly called laser rot: the deterioration
of the aluminum layer due to oxidation or other chemical change. This often
results from the use of insufficiently pure aluminum during replication, but can
be exacerbated by mechanical shear stress due to bending, warping or thermal
cycles (the large size of laserdiscs makes them flexible, so that movement along
the bond between layers can break the seal). Deterioration of the data layer can
be caused by chemical contaminants or gasses in the glue, or by moisture that
penetrates the acrylic substrates.
Like laserdiscs, DVDs are made of two platters glued together, but DVDs are
more rigid and use newer adhesives. DVDs are molded from polycarbonate, which
absorbs about ten times less moisture than the slightly hygroscopic acrylic
(PMMA) used for laserdiscs.
It's too early to know for sure, but DVDs will probably have few laser rot
problems. There have been reports of a few discs going bad, possibly due to poor
adhesive, chemical reactions, or oxidation of the aluminum layer. See www.mindspring.com/~yerington/.
Some titles are available only in pan & scan because there was no
letterbox or anamorphic transfer made from film. (See 3.5 for more info on
pan & scan and anamorphic formats.) Since transfers cost $50,000 to
$100,000, studios may not think a new transfer is justified. In some cases the
original film or rights to it are no longer available for a new transfer. In the
case of old movies, they were shot full frame in the 1.37 "academy" aspect ratio
so there can be no widescreen version. Video shot with TV cameras, such as music
concerts, is already in 4:3 format.
The list of pan & scan only titles has gotten too big to keep here. You
can get a list from the Film Vault at DVD
Review, or from Internet
Movie Database (which also includes discs with both widescreen and pan &
scan versions).
On the remote control, press Subtitle, then either Clear or 0 (zero). No need
to use the menus.
Some movies, especially those over two hours long or encoded at a high data
rate, are spread across two layers on one side of the disc. When the player
changes to the second layer, the video and audio may freeze for a moment. The
length of the pause depends on the player and on the layout of the disc. The
pause is not a defect in the player or the disc. See 1.18 for details.
There is a list of layer switch points in the Film Vault at DVD
Review. Please send new times to info@dvdreview.com. (The list has gotten
too long to keep in this FAQ.)
Some discs (many from Columbia TriStar) have 2-channel Dolby Surround audio
(or plain stereo) on track one and 5.1-channel audio on track two. Since some
studios create separate sound mixes optimized for Dolby Surround or stereo, and
they feel the default track should match the majority of sound systems in use.
Unless you specifically select the 5.1-channel track (with the audio button on
the remote or with the on-screen menu) the player will play the default
2-channel track. (Note: Some players such as the Sony 3000 have a feature to
automatically select the first 5.1 track.)
Dolby Digital doesn't necessarily mean 5.1 channels. See 3.6.
Almost all features of DVD such as search, pause, and scan can be disabled by
the disc, which can prevent the operation the player needs to back up and repeat
a segment. If the player uses time search to repeat a segment, then a disc with
fancy non-sequential title organization may also block the repeat feature. In
many cases the authors don't even realize they have prevented the use of this
feature.
There is no good answer to this question, since you'll get a different
response from everyone you ask. The terms "2nd generation" and "3rd generation,"
and so on refer both to DVD-Video players and to DVD-ROM drives. In general,
they simply mean newer versions of DVD playback devices. The terms haven't been
used (yet) to refer to DVD products that can record, play video games, or so
on.
According to some people, second-generation DVD players came out in the fall
of 1997 and third-generation players are those that came out in the beginning of
1998. According to others, the second generation of DVD will be
"high-definition" players (see 2.12) that won't come
out until 2003 or so. There are many confusing variations between these
extremes, including the viewpoint that DTS-compatible players or Divx players or
progressive-scan players constitute the third generation or fourth
generation.
Things are a little more clear cut on the PC side, where second generation
(DVD II) usually means 2x DVD-ROM drives that can read CD-Rs, and third
generation (DVD III) usually means 5x (or sometimes 2x or 4.8x or 6x) DVD-ROM
drives, a few of which can read DVD-RAMs, and some of which are RPC2 format.
Some people refer to RPC2 drives or 10x drives as fourth generation. See section
4.2 for more speed
info. See section 1.10 for RPC2
explanation.
Do you really want the answer to this one? Ok, you asked for it...
- A disc that works in both DVD-Video players and DVD-ROM PCs. (The most
common use of the term hybrid, but more accurately called an enhanced
DVD)
- A DVD-ROM disc that runs on Windows and Mac OS computers. (More accurately
called a cross-platform DVD.)
- A DVD-ROM or DVD-Video disc that also contains Web content for connecting
to the Internet. (More accurately called a WebDVD or
Web-connected DVD.)
- A disc that contains both DVD-Video and DVD-Audio content. (More
accurately called a universal DVD.)
- A disc with two layers, one that can be read in DVD players and one that
can be read in CD players. (More accurately called a legacy or
CD-compatible disc.) There are at least three variations of this hybrid
(none were commercially available as of 12/99):
- A 1.2mm CD substrate bonded to the back of a 0.6mm DVD substrate. One
side can be read by CD players, the other side by DVD players. The resulting
disc is 0.6mm thicker than a standard CD or DVD, which can cause problems in
players with tight tolerances, such as portables. Sonopress, the first
company to announce this type, calls it DVDPlus. It's colloquially known as
a "fat" disc.
- A 0.6mm CD substrate bonded to the front of a semitransparent 0.6mm DVD
substrate. Both layers are read from the same side, with the CD player being
required to read through the semitransparent DVD layer, causing problems
with some CD players.
- A 0.6mm CD substrate, with a special refractive coating that causes a
1.2mm focal depth, bonded to the back of a 0.6mm DVD substrate. One side can
be read by CD players, the other side by DVD players.
- A disc with two layers, one containing pressed (DVD-ROM) data and one
containing rewritable (DVD-RAM, etc.) media for recording and re-recording.
(More accurately called a mixed-media or rewritable sandwich
disc.)
- A disc with two layers on one side and one layer on the other. (More
accurately called a DVD-14.)
- A disc with an embedded memory chip for storing custom usage data and
access codes. (More accurately called a chipped DVD.)
Did I miss any?
Digital Theater Systems Digital Surround is an audio encoding format similar
to Dolby Digital. It requires a decoder, either in the player or in an external
receiver. See 3.6.2 for technical
details. Some people claim that because of its lower compression level DTS
sounds better than Dolby Digital. Others claim there is no meaningfully
perceptible difference. Because of the many variances in production, mixing,
decoding, and reference levels, it's almost impossible to accurately compare the
two formats (DTS usually produces a higher volume level, causing it to sound
better in casual comparisons).
DTS originally did all encoding in house, but as of October 1999 DTS encoders
are available for purchase. DTS titles are generally considered to be specialty
items intended for audio enthusiasts. It's expected that most DTS will also be
available in a Dolby Digital-only version.
DTS is an optional format on DVD. Contrary to what some people claim, the DVD
specification has included an ID code for DTS since 1996 (before the spec was
even finalized). Because DTS was slow in releasing encoders and test discs,
players made before mid 1998 (and many since) ignore DTS tracks. A few demo
discs were created in 1997 by embedding DTS data into a PCM track (the same
technique used with CDs and laserdiscs), and these are the only DTS DVD discs
that work on all players. New DTS-compatible players arrived in mid 1998, but
theatrical DTS discs using the proper DTS audio stream ID did not appear until
January 7, 1999 (they were originally scheduled to arrive in time for Christmas
1997). Mulan, a direct-to-video animation (not the Disney movie) with DTS
soundtrack did appear in November 1998. DTS-compatible players carry an official
"DTS Digital Out" logo. A few manufacturers may provide upgrades to make
existing players compatible with DTS discs.
Dolby Digital or PCM audio are required on 525/60 (NTSC) discs, and since
both PCM and DTS together don't usually leave enough room for quality video
encoding of a full-length movie, essentially every disc with a DTS soundtrack
also carries a Dolby Digital soundtrack. This means that all DTS discs will work
in all DVD players, but a DTS-compatible player and a DTS decoder are required
to play the DTS soundtrack. DTS audio CDs work on all DVD players, since the DTS
data is encapsulated into standard PCM tracks that are passed untouched to the
digital audio output.
You are probably trying to play an NTSC disc in a PAL player, but your PAL TV
is not able to handle the signal. If your player has a switch or on-screen
setting to select the output format for NTSC discs, choosing PAL (60-Hz) may
solve the problem. See section 1.19 for more
information.
Or you may have connected one of the component outputs (Y, R-Y, or B-Y) of
your DVD player to the composite input of your TV. See section 3.2 for hookup
details.
Many DVD's are labeled as having widescreen (16:9) format video on one side
and standard (4:3) on the other. If you think both sides are the same, you're
probably seeing uncompressed 16:9 on the widescreen side. It seems to be 4:3 pan
& scan, but if you look carefully you'll discover that the picture is
horizontally compressed. The problem is that your player has bee
