About Dvds - Alpine X209D Quick Reference Manual

About DVDs

Music CDs and DVDs have grooves (tracks) in which the digital data is
recorded. The data is represented as microscopic pits recorded into the
track – these pits are read by a laser beam to play the disc. On DVDs, the
density of the tracks and pits is twice that of CDs, so DVDs can contain
more data in less space.
CDs
Minimum pit
length -
1.2 mm
0.9 μm
DVDs
Minimum pit
0.6 mm
length -
0.6 mm
0.9 μm
A 12 cm disc can contain one movie or about four hours of music. In
addition, DVDs provide sharp picture quality with vivid colors thanks to
a horizontal resolution of over 500 lines (compared to less than 300 for
VHS tape).
In addition, DVDs offer a variety of functions.
Multiple audio* (page 79)
Movies can be recorded in up to eight languages. The desired
language can be selected from the unit.
Subtitles function* (page 79)
Movies can include subtitles in up to 32 languages. The desired
subtitle language can be selected from the unit.
Multi angle function* (page 79)
When the DVD contains a movie shot from multiple angles, the
desired angle can be selected from the unit.
Multi story function*
With this function, a single movie includes various story lines. You can
select different story lines to view various versions of the same movie.
Operation differs from disc to disc. Story line selection screens
including instructions appear during the movie. Just follow the
instructions.
* These functions differ from disc to disc. For details, refer to the disc's
instructions.
104
-EN
Track pitch -
1.6 μm
Track pitch -
0.74 μm