BrightEye 75 HD/SD Analog to Digital Converter and Analog Audio Embedder
BrightEye 75 - Page 20
GLOSSARY
This is a brief glossary of commonly used terms associated with this product.
AES/EBU
The digital audio standard defined as a joint effort of the Audio Engineering
Society and the European Broadcast Union. AES/EBU or AES3 describes a serial
bitstream that carries two audio channels, thus an AES stream is a stereo pair.
The AES/EBU standard covers a wide range of sample rates and quantizations
(bit depths.) In television systems, these will generally be 48 KHz and either 20
or 24 bits.
Bandwidth
Strictly speaking, this refers to the range of frequencies (i.e. the width of the
band of frequency) used by a signal, or carried by a transmission channel.
Generally, wider bandwidth will carry and reproduce a signal with greater
fidelity and accuracy.
Beta
Sony Beta SP video tape machines use an analog component format that is
similar to SMPTE, but differs in the amplitude of the color difference signals. It
may also carry setup on the luminance channel.
Blanking
The Horizontal and Vertical blanking intervals of a television signal refer to the
time periods between lines and between fields. No picture information is trans-
mitted during these times, which are required in CRT displays to allow the
electron beam to be repositioned for the start of the next line or field. They are
also used to carry synchronizing pulses which are used in transmission and
recovery of the image. Although some of these needs are disappearing, the
intervals themselves are retained for compatibility purposes. They have turned
out to be very useful for the transmission of additional content, such as teletext
and embedded audio.
CAV
Component Analog Video. This is a convenient shorthand form, but it is subject to
confusion. It is sometimes used to mean ONLY color difference component
formats (SMPTE or Beta), and other times to include RGB format. In any case, a
CAV signal will always require 3 connectors – either Y/R-Y/B-Y, or R/G/B.
Checkfield
A Checkfield signal is a special test signal that stresses particular aspects of
serial digital transmission. The performance of the Phase Locked-Loops (PLLs) in
an SDI receiver must be able to tolerate long runs of 0’s and 1’s. Under normal
conditions, only very short runs of these are produced due to a scrambling
algorithm that is used. The Checkfield, also referred to as the Pathological test
signal, will “undo” the scrambling and cause extremely long runs to occur. This
test signal is very useful for testing transmission paths.
