DVD
Basics
Intro
to DVD
DVD once stood for digital video disc or digital versatile disc, but
now it just stands for DVD -- the next generation of optical disc storage
technology. DVD is 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 video game cartridges.
Features of DVD
· Over 2 hours of high-quality digital video (a double-sided,
dual-layer disc can hold 8 hours of high-quality video, or 30 hours
of VHS quality video).
· Support for widescreen movies on standard or widescreen TVs
(4:3 and 16:9 aspect ratios).
· Up to 8 tracks of digital audio (for multiple languages, 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 than tapes or laserdiscs).
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.
Disc Capacity
A CD-ROM holds up to about 700 MB. A similar DVD-ROM disc, with one
layer and one side, can hold up to 4.37 GB of data. But DVD-ROM discs
can have two data layers, or 7.95 GB of data per side. There are also
double-sided DVD discs that double the disc capacity by pressing data
onto both the bottom and top surfaces of the disc.
The four most
common DVD discs:
| Media
type |
Data
Capacity |
Video
capacity |
sides |
layers |
| CD-ROM |
.68 GB |
20 minutes |
1 |
1 |
| DVD-5 |
4.37GB |
2 hours |
1 |
1 |
| DVD-9 |
7.95 GB |
4 hours |
1 |
2 |
| DVD-10 |
8.75 GB |
4.5 hours |
2 |
1 |
| DVD-18 |
15.9 GB
|
8 hours |
2 |
2 |
Note:
It takes about two gigabytes to store one hour of average video.
Formats Galore:
It's important to understand the difference between the physical formats
(such as DVD-ROM or DVD-R) and the logical or 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 such
as movies are stored on disc and played in a DVD-Video player or a DVD
computer.
Physical Formats:
The physical format refers to how the DVD is configured, including how
the pits are stamped. The main issue you need to worry about is which
disc will record in the DVD recording device that you're using. For
example, if you want to use the SuperDrives at City College, you need
to buy a DVD-R (General) format not a DVD-R (Authoring) or DVD-RAM disc.
Overview of all DVD physical formats:
DVD-ROM: This is a read-only format similar to CD-ROM, but it stores
much more info.
DVD-R: DVD-R is a write-once, read many times format silimar to CD-R.
There are two types of DVD-R media - General and Authoring. The General
DVD-Rs are used with the SuperDrive; the Authoring DVD-Rs are used with
professional DVD-recordable drives.
DVD-RW: This is a write many times, read many times format similar to
CD-RW. They can be rewritten up to 1000 times. Most new DVD-video players
can read DVD-RW discs.
DVD-RAM: This format is for archiving data and backing up your DVD projects.
It allows you to write to the disc in multiple sessions. DVD-RAM will
not play in most DVD-video players. This format is used primarily for
data backup.
DVD+R and DVD+RW: DVD+R discs are about the same as DVD-R, however,
it uses a different recording format. However, you can't use these in
a SuperDrive. DVD+RW is an erasable format based on CD-RW technology.
These work in most DVD-Video players but not with a SuperDrive.
None of the writable
formats are fully compatible with each other or even with existing drives
and players. As time goes by they will become more compatible and more
intermixed.
Not all players and drives can read recorded discs. There are lists
at DVDMadeEasy),
VCDHelp,
and Apple
that indicate player compatibility with DVD-R and DVD-RW discs.
Very roughly,
DVD-R discs works in about 85% of existing drives and players, while
DVD-RW and DVD+RW discs work in around 65%.
A summary of recordable DVD compatibility:
| |
DVD unit |
DVD-R(G)
unit |
DVD-R(A) unit |
DVD-RW unit
|
DVD-RAM
unit |
DVD+RW unit |
| DVD-ROM
disc |
reads |
reads |
reads |
reads |
Reads |
reads
|
| DVD-R(G)
disc |
routinely
reads |
reads, writes |
reads, doesn't
write |
reads, writes |
reads |
reads |
| DVD-R(A)
disc |
routinely reads |
reads, doesn't
write |
reads, writes |
reads, doesn't
write |
reads |
reads |
| DVD-RW disc |
usually
reads |
reads |
reads |
reads, writes |
usually
reads |
usually
reads |
| DVD-RAM
disc |
rarely reads
|
doesn't
read |
doesn't
read |
doesn't
read |
reads, writes
|
doesn't
read |
| DVD+RW disc
|
usually
reads |
usually
reads |
usually
reads |
routinely
reads |
usually
reads |
reads, writes |
| DVD+R disc |
routinely
reads |
routinely
reads |
routinely
reads |
routinely
reads |
routinely
reads |
reads, may
write |
DVD Logical
Formats:
This refers to the type of data that the DVD holds. There are three
formats that are important to this class: DVD-ROM, DVD-Video and hybrid
DVD (which holds both DVD-ROM and DVD-video content).
DVD-ROM: DVD-ROM
is the base format that holds any type of data. It is also the name
of the player inside your computer, which plays the DVD-ROM disc.
DVD-Video:
DVD-Video is the usual name for the DVD format designed for full-length
movies. The DVD-Video is stored inside a VIDEO_TS folder at the disc's
root level.
Hybrid DVD:
A hybrid DVD contains both DVD-ROM and DVD-Video files. It houses a
VIDEO_TS folder at the disc's root level, and also has other folder
housing the type of data files that would run on your computer.
DVD-Audio:
This format refers to the DVD-audio format, which has been designed
to replace the audio CD format. It also refers to the player, which
many hope will replace your CD player. Because of the larger capacity,
DVDs are capable of holding higher quality audio. A DVD-Audio disc can
hold multichannel, 24-bit surround sound audio at sample rates up to
192 kHz.
Resource: http://www.dvddemystified.com/dvdfaq.html
and PeachPit's QuickStart
Guide to DVD Studio Pro
