User Guide

Glossary
G - 8
Glossary
B-frame
Bi-directional frame
àMPEG
BIOS
Basic Input Output System
Designation for the automatic
"start program" of a computer. It is
stored on a separate chip. The
BIOS basically controls the access
to the microprocessor and pre-
pares the acceptance of com-
mands. A program cannot operate
without the BIOS.
Bit
Binary Digit
Basic unit in
àDIGITAL
TECHNOLOGY. One bit may adopt
two states: 0 or 1.
Bit rate
Number of bits transmitted serially
per second.
Bit stream
àDATA STREAM
Blackburst
Black signal, burst blanking.
Video signal without luminance or
chrominance components (except
for bursts), which, however,
includes all other elements of a
video signal. The black burst is a
reference/synchronizing signal
which is usually used for timing
audio and video samples.
Bluebox
A frequently used type of
àCHROMA KEYING, i.e. the color
key trick, which is used with blue
as key color.
A scene is recorded in front of a
blue background. The blue por-
tions of the image are keyed and
replaced by other parts of a differ-
ent image (
àALPHA CHANNEL).
BNC
Bayonet Neil-Concelman.
A common plug connection used
in professional video technology
with an
àIMPEDANCE of 75 ohms.
BNC plugs are used in both analog
and digital video technology.
Some few consumer recorders also
have BNC terminals for image dis-
play. Using a metal adapter plug, a
connection to cinch can easily be
established by BNC. This adapter is
available both in male and female
form.
Broadcast Qual-
ity
Although the expression broadcast
quality is frequently used, a fixed
definition does not exist. Generally
accepted measurable variables do
not exist.
Usually the tape format
àBETACAM SP is selected as refer-
ence point: Broadcast quality usu-
ally describes the picture quality
that the user subjectively considers
as being equal to the Betacam SP
picture quality.
Also non-linear editing does not
include any fixed measured vari-
ables to determine the broadcast
quality. As a rule, video boards and
editing systems with a
àCOMPRESSION RATE (approx. 1:2)
as low as possible or a data rate of
approx. 50 Mbits/s are understood
by this.