Updated
March 31, 2012
DVD
Technical FAQ
They
[DVD discs] look like Compact Discs. What's the big deal?
DVD discs are the same diameter (120mm) and thickness (1.2mm)
as a Compact Disc, but that is where the similarities end. A single
DVD disc has the capability to store up to 13 times the data contained
on a CD, on one side! If you factor in DVD's capability to utilize
both sides of a disc for data storage, you have an information
marvel that offers 26 times the power of a Compact Disc!
That enhanced capability is a tremendous enabling device. DVD
will revolutionize Multimedia, information retrieval and storage
and mobile navigation. DVD will create new high quality audio
standards, impact learning and training videos, and bring the
Cinema experience to Home Entertainment.
How
long will DVD movies play before I have to turn the disc over?
At an average bit rate of 4.5Mbs, a single sided DVD disc has
the playback capability of 133 minutes of the highest quality
audio and video images. That's nearly 92% of all Hollywood titles
ever made!
In fact, a dual layer DVD disc can provide up to 4 hours of the
highest quality audio and video on a single side of the disc!
Will
DVD movies play on my current CD player?
No, you will require a DVD player that is equipped to read the
pits and lands of a DVD disc and decode the MPEG-2 data signal.
What is the digital audio output on the back of
my DVD player for?
This connector outputs a digital data stream that may be sent
to an outboard D/A converter for 2 channel audio processing. More
importantly, it may be connected to an audio receiver equipped
with a Dolby AC-3 processor for multi-channel audio decoding.
What are the advantages of Dolby Digital Surround
AC-3?
Dolby Digital Surround offers discrete processing of 5 independent
channels ( Left, Center, Right, Left Surround, Right Surround,
and an additional effects channel that may be routed to a subwoofer)
of audio information. Dolby Digital Surround provides the producers
of movie soundtracks added flexibility and creativity in the studio
that results in more realism, and a "you are there experience."
Each of the 5 Audio channels is a full range (20-20khz) signal.
The discrete nature of Dolby Digital Surround provides increased
clarity (especially critical for dialogue) and spatial realism.
With Dolby Digital Surround, audio images may be panned across
the front of the room; from front to rear; from rear to front;
and even diagonally.
Will DVD discs wear out, like VHS movies?
No. The picture quality of the DVD disc is consistent from the
first play to the thousandth play. Plus, DVD discs will not deteriorate
over time, are unaffected by magnetic fields (which can literally
erase a VHS cassette) and do not require rewinding after viewing.
What is an Aspect Ratio? Why is it important?
Aspect ratio refers to the ratio of width to height of a television
set. Traditional television sets have a 4:3 aspect ratio. Widescreen
television sets have a 16:9 aspect ratio. Traditional television
sets are almost square in appearance; widescreen displays are
more rectangular.
The DVD defines the capability to display movies in 3 different
ways:
- Widescreen,
which provides a special "anamorphic video" signal that, when
processed by a widescreen television set, fills the entire screen
and delivers optimum picture quality.
- Pan
and Scan, a version that fills the screen of traditional 4:3
television sets with an entire picture, much like watching network
movies.
- Letterbox
mode, which provides horizontal bands at the top and bottom
to, in essence, create a widescreen picture in a traditional
television set.
Each of the 3 display modes, if provided by the Hollywood producer,
may be selected for viewing if the viewing device (player or DVD-ROM
playback sub-system) is so equipped.
I do not own a Dolby Digital Surround AC-3 receiver.
Can I still enjoy my Home Theater audio system with DVD?
Yes, every DVD player currently on the market has analog ( Left
and Right ) audio outputs that you can connect to your Dolby Surround
Sound, or Pro-Logic receiver. The analog audio outputs of your
DVD player passes through specially encoded Dolby Surround Sound
signals.
My television set has Composite and S-Video inputs.
What is the best way to connect my DVD player?
DVD is a format that will provide significant picture quality
advantages when connected to your television set via the S-Video
connectors. Your DVD player must have S-Video output to take advantage
of this capability.
Are there any other adjustments I should make to
my television to take advantage of S-Video?
Yes. The color detail signal is so rich, you will find that you
do not need to turn your sharpness control up when watching DVD.
In fact, in many television sets, you will optimize picture quality
by turning the sharpness control off!
Just how good is the DVD picture?
Based upon pixel resolution, color resolution, color detail, black
level reproduction and a virtual lack of color noise, the DVD
picture is nearly 3 times better than conventional VHS.
Is DVD picture quality better than Laserdisc?
Yes. DVD is component video, Laserdisc is composite video. The
DVD picture is characterized by more color detail, and color resolution
and contains significantly less NTSC picture artifacts than Laserdisc.
It is generally accepted that a Laserdisc is capable of producing
400-425 horizontal lines of resolution. A DVD disc produces in
the range of 480-500 horizontal lines of resolution. A single
sided 4.7" (120mm) dual layer DVD disc can store up to 4 hours
of the highest quality audio and video images. A 12" Laserdisc
can only store 60 minutes on a single side. And DVD movies will
play on your computer equipped with a DVD-ROM and appropriate
MEPG decode devices. DVD is the realization of true cross-platform
multimedia.
Is it [DVD] better than DSS?
Yes. DVD is mastered as CCIR601 4:2:2 digital component video
and utilizes 100% MPEG-2 data reduction. DSS, on the other hand,
is 4:1:1 digital component video and features scaleable compression
schemes that vary from MPEG-1 to MPEG-2. In fact, the digital
component video signal of DVD has the capability to rival the
best studio masters.
Do I need a Widescreen TV to play 16:9 movies?
A DVD-player can be connected to any television, but with a Widescreen
TV you will get the most viewing enjoyment. With DVD-Video you
can gradually build up your own Home Cinema system with widescreen
TV and multichannel digital surround sound. DVD-Video supports
multiple aspect ratios. Video stored on a DVD in 16:9 format is
horizontally squeezed to a 4:3 (standard TV) ratio. On Wide-screen
TVs, the squeezed image is enlarged by the TV to an aspect ratio
of 16:9.
DVD video 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)
In
widescreen or letterbox mode, if a movie is wider than 16:9 (and
most are), additional thin black bars will be added to the top
and bottom at production time or the sides will be cropped. 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.
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