GRASS VALLEY zodiak, User Manual

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38 Zodiak User Manual
Section 2 — Concepts
Figure 12. Simplified Mix Effects (M/E) Subsystem
The basic M/E shown in Figure 12 has an A and a B background bus. These
buses select the background video signals sent to the output of the M/E.
Generally the source on the background A bus is the current background
output, and the source on the background B bus is the background video
that will be used next. During most transitions, portions of both back-
grounds are output simultaneously. The keyers in the M/E allow the inclu-
sion of additional material over the background. Wipe generators also
exist, which create patterns used by the mixer for wipe transitions, or used
by the keyers to modify the signals it sends the mixer. See
Transitions on
page 42 and Keying on page 46 for more information. The processed signal
in an M/E is then sent to an M/E output, typically program or preview.
A video production switcher can have more than one M/E. For example, a
3-M/E Zodiak system has three (M/E 1, M/E 2, and M/E 3). Each Zodiak
M/E produces two outputs, M/E Program and Preview.
Re-Entry
Switchers with multiple M/Es generally have re-entry capabilities. Re-
entry permits the switcher to select the output of one M/E for use as an
input source to another M/E. The signals are routed internally.
The Zodiak system supports M/E re-entry. For example, an output of
M/E 1 can be sent to M/E 2 or M/E 3 (PGM/PST), and an output of M/E 2
can be sent to M/E 1 or M/E 3 (PGM/PST).
Alternate Buses and Delegation
Many earlier generation switchers had M/Es equipped with two keyers,
and each M/E could accept two background sources. This permitted
mixing or wiping between two backgrounds, and keying up to two addi-
tional sources over the background. Dedicated rows of control panel
buttons were used to select these key and background signals.
Each Zodiak system M/E actually has four keyers, each handling a fill and
a key signal, and each M/E can accept three background sources (A, B, and
Utility). Providing individual source selection rows for each M/E is
Source Signal Inputs
061_00_22_r1
Crosspoint
Matrix
Keyer
Mixer
Wipe
Generator
M/E
Outputs
Background A
M/E Program
M/E Preview
Background B
Key Cut
Key Fill