Glossary - Panasonic DVD-PV55 Operating Instructions Manual

Glossary

Bitstream
This is the digital form of multiple channel
audio data (e.g., 5.1 channel) before it is
decoded into its various channels.
Chapter
This is the smallest division on DVDs and is
roughly equivalent to a track.
Dolby Digital
This is a method of coding digital signals
developed by Dolby Laboratories. The sig-
nals are highly compressed, enabling a
large amount of information to be recorded
on 1 disc.
Dolby Pro Logic
A surround system where a 4-channel
audio track is recorded as 2 channels and
then is restored to 4 channels for play. The
surround channel is monaural and can re-
produce up to 7 kHz.
DTS (Digital Theater Systems)
This is a method of coding digital signals
developed by Digital Theater Systems. The
signals are compressed at a low ratio to
maintain sound quality.
Dynamic range
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 distortion
occurs.
Field
One frame is made up of 2 fields.
A regular television shows these fields one
after the other to create frames.
Frame
Frames are the still pictures that go togeth-
er to make a moving picture.
There are about 30 frames shown each
second.
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Frame still and field still
A still is shown when you pause a moving
picture.
A frame still is made up of 2 alternating
fields, so the picture may appear blurred,
but overall quality is high.
A field still is not blurred, but it has only half
the information of a frame still so picture
quality is lower.
I/P/B
MPEG 2, the video compression standard
adopted for use with DVDs, codes frames
using these 3 picture types.
I: Intra coded picture (I-picture)
This is the standard picture and is a com-
plete picture in itself. This means it has the
best picture quality and is the best to use
when adjusting the picture.
P: Predictive coded picture (P-picture)
This picture is calculated based on past I or
P-pictures.
B: Bidirectionally-predictive coded picture
(B-picture)
This picture is calculated by comparing
past and future I and P-pictures so it has
the lowest volume of information.
Linear PCM (pulse code modulation)
PCM is the usual digital method used for
music CDs. DVDs have a greater volume
so they use linear PCM, which has a higher
sampling rate.
The compressed version of this is called
Packed PCM.
Playback control (PBC)
This method of controlling disc play is in-
cluded on version 2.0 Video CDs. You are
able to interact with the disc through
menus.
Title
This is the largest division on DVDs.
Track
This is the smallest division on Video CDs
and CDs and usually equates to a single
song.