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In case of difficulty
Knowledge sections
Track/Track No. ( VCD, CD):
A track is also a sec-
tion of video and audio recorded in a disc. The
numbers assigned to individual tracks are referred
to as the track numbers. With most of music CDs,
a track is assigned to a piece of music. However,
with a VCD, the sections of the contents do not
always correspond to the assigned tracks. As
(special) playback functions such as skipping and
programming of ordinary CDs are based on track
number data, such playback functions are some-
times impossible with some VCDs.
Cinema Voice function (DVD) :
This function to be
used when words are hard to be distinguished dur-
ing playback of DVD recorded with Dolby Digital
Surround.
Subtitle language (DVD):
Some DVDs contain the
recording of multiple subtitle languages.
Angle (DVD) :
Some DVDs contain the recording of
multiple viewing angles.
Audio language (DVD) :
Some DVDs contain the
recording of multiple audio languages.
Aspect ratio:
The ratio between the horizontal and
vertical sizes of picture displayed on a TV screen.
The aspect ratio of ordinary TV is 4:3, and that of
widescreen TV is 16:9.
Pan & scan (DVD):
Method of displaying a horizon-
tally-long picture recorded in 16:9 aspect ratio on
a 4:3 TV screen by trimming part of picture.
In general, the trimming positions for pan & scan
are determined uniformly by the reproducing de-
vice. However, the pan & scan of DVD allows the
software producer to specify the trimming posi-
tions to be used in playback.
Important Items
Letterbox (DVD):
Method of displaying a horizon-
tally-long picture recorded in 16:9 aspect ratio on
a 4:3 TV screen by attaching bands at the top and
bottom of the screen and displaying the horizon-
tally-long picture at the center of screen.
Frame (DVD, VCD):
Each frame of a moving pic-
ture, that is displayed 30 times a second with
NTSC and 25 times a second with PAL. These
TV formats reproduce moving pictures by dis-
playing still pictures sequentially.
Field (DVD, VCD):
Part of a frame obtained by di-
viding the video data of each frame by two. Each
frame of ordinary TV is constituted by displaying
the fields alternately.
Frame still/Field still (DVD, VCD):
Types of still pic-
tures obtained by temporarily stopping a moving
picture. The frame still picture may produce blur in
the picture because it displays two specific fields
alternately, but the picture quality is higher. The
field still picture has lower picture quality because
it uses half the picture information of frame still,
but is not accompanies with picture blur.
IPB display (DVD):
With the MPEG2 which is one
of the video display methods of DVD, each pic-
ture is divided into the following three picture
types before being coded in digital signal.
I-picture (Intra coded) :
This is the standard
video and can constitute a picture by itself. As
the highest picture quality can be obtained, the
still image of I-picture is most suitable for use
when adjusting the picture quality.
P-picture (Predictire coded) :
Picture calculated
based on past pictures (I-picture or P-picture).
