A decoder restores the coded audio signals on DVDs
to normal. This is called decoding.
This is a method of coding digital signals developed
by Dolby Laboratories. Apart from stereo (2-channel)
audio, these signals can also be multi-channel audio.
A large amount of audio information can be recorded
on one disc using this method.
DTS (Digital Theater Systems)
This surround system is used in many movie theaters
around the world. There is good separation between
the channels, so realistic sound effects are possible.
Dynamic range is the difference between the lowest
level of sound that can be heard above the noise of
the equipment and the highest level of sound before
Film and video
DVD-Videos are recorded using either ﬁ lm or video.
This unit can determine which type has been used,
then uses the most suitable method of progressive
Film: Recorded at 25 frames per second (PAL
discs) or 24 frames per second (NTSC discs).
(NTSC discs recorded at 30 frames per
second as well). Generally appropriate for
motion picture ﬁ lms.
Video: Recorded at 25 frames/50 ﬁ elds per second
(PAL discs) or 30 frames/60 ﬁ elds per second
(NTSC discs). Generally appropriate for TV
drama programs or animation.
Frame still and ﬁ eld still
Frames are the still pictures that go together to make
a moving picture.
There are about 30 frames shown each second.
One frame is made up of two ﬁ elds. A regular
television shows these ﬁ elds one after the other to
A still is shown when you pause a moving picture.
A frame still is made up of two alternating ﬁ elds, so
the picture may appear blurred, but overall quality is
A ﬁ eld still is not blurred, but it has only half the
information of a frame still so picture quality is lower.
MPEG 2, the video compression standard adopted
for use with DVD-Video, codes frames using these 3
I: Intra coded picture
This picture has the best quality and is the best to
use when adjusting the picture.
P: Predictive coded picture
This picture is calculated based on past I or P-
B: Bidirectionally-predictive coded picture
This picture is calculated by comparing past and
future I and P-pictures so it has the lowest volume
JPEG (Joint Photographic Experts Group)
This is a system used for compressing/decoding
color still pictures. If you select JPEG as the storage
system on digital cameras, etc., the data will be
compressed to 1/10–1/100 of its original size. The
beneﬁ t of JPEG is less deterioration in picture quality
considering the degree of compression.
Linear PCM (Pulse Code Modulation)
These are uncompressed digital signals, similar to
those found on CDs.
MP3 (MPEG Audio Layer 3)
An audio compression method that compresses
audio to approximately one tenth of its size without
any considerable loss of audio quality.
Playback control (PBC)
If a Video CD has playback control, you can select
scenes and information with menus.
Sampling is the process of converting the heights
of sound wave (analog signal) samples taken at set
periods into digits (digital encoding).
Sampling frequency is the number of samples taken
per second, so larger numbers mean more faithful
reproduction of the original sound.
WMA (Windows Media
WMA is a compression format developed by
Microsoft Corporation. It achieves the same sound
quality as MP3 with a ﬁ le size that is smaller than that