DVD Demystified

DVD Comparison
DVD quickly displaced laserdisc as the premiere home entertainment
format, but it will never achieve 100 percent replacement. About 10,000
laserdisc titles were released in the United States for a peak installed base
of about 2 million players. Over 35,000 laserdisc titles were released worldwide
into a market that reached approximately 7 million laserdisc players.
DVD attained the same player base in less than three years, but it will take
four or five years to build a similar library of titles. Laserdisc has the superiority
of tenure and will continue to be a source of quality video, especially
for rare titles that may not appear on DVD for a long while, if ever. Most
laserdisc player owners bought DVD players shortly after they became
available, but few have rushed to replace their laserdisc collection.
An important distinction between laserdisc and DVD is that laserdiscs
do not contain digital video, and they do not always use digital audio. The
laserdisc video format is analog pulse FM-encoded composite video.
CDV, sometimes called Video Single or CD-Video (not to be confused with
Video CD), is actually a hybrid of CD and laserdisc. Part of a CDV contains
20 minutes of digital audio playable on any CD player, DVD player, or CDcompatible
laserdisc player. The other part of a CDV contains 5 or 6 minutes
of analog video and digital audio in laserdisc format, playable only on
CDV-compatible laserdisc systems. Table 8.1 lists laserdisc and DVD-Video
specifications.
Advantages of DVD-Video over Laserdisc
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Features. DVD-Video has the same basic features as CLV laserdisc (such
as, scan, pause, search) plus most of the added benefits of CAV laserdisc
(such as, freeze, slow, fast). DVD goes beyond laserdisc with multistory
branching, parental control, multiple camera angles, video menus, interactivity,
and more. Level II laserdisc players had a command language similar
to that of DVD, but level II discs and players never grew beyond the
small niches of education and industrial training.
Capacity. Programs on DVD can be over four times longer than those on
laserdisc at equivalent quality.A single-layer DVD-Video holds over two hours
of material per side, and a dual-layer disc holds over four hours. A CLV
laserdisc holds one hour per side, and a CAV laserdisc holds only one half hour.
DVD-Video supports still frames with audio, allowing for hundreds or
thousands of pictures accompanied by hours of surround sound. Laserdisc
still frames have no audio (unless specially produced discs are connected to
expensive still-frame audio equipment).