GRASS VALLEY 1200, Установка и обслуживание

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3-25
Frame Modules
Borderline Submodule
A Borderline Submodule option (Figure 3-11) can be mounted on each of
the Key Processor Submodules. The purpose of the Borderline is to expand
the key horizontally and/or vertically to put a border or shadow around it.
The Horizontal Key Stretch circuit will, under the control of the CPU, delay
the key one pixel and then do a Non Additive Mix (NAM) between the
original signal and the delayed signal. This process is repeated until the key
is widened enough for the required border. At the same time the Vertical
Key Stretch is widening the key vertically.
The stretched key is sent to a NAM. At the same time the key is sent to the
adjustable 3 line delay where the key is delayed the required number of
lines and pixels. The delayed key signal is also sent to the NAM. The output
of the NAM is the difference between the delayed key and the stretched
key, which is the border.
The border is sent to the Border Opacity Mixer which, under the control of
the CPU, sets the opacity of the border. The border signal then is sent to
both the Border Mixer and the Combiner circuit. The Combiner circuit
combines the key signal and the border signal and outputs the resultant
key signal.
The key video goes through a delay and into the Border Mixer. The Matte
Generator generates the border matte which is sent to the border Mixer.
The Border Mixer then combines these signals with the output from the
border opacity mixer to create a key video with border.
Figure 3-11. Borderline Submodule
DELAY
MATTE
GENERATOR
BORDER
MIXER
HORIZONTAL
KEY
STRETCH
VERTICAL
KEY
STRETCH
NAM/
SELECT
ADJ
3 LINE
DELAY
DELAY
DELAY
BORDER
OPACITY
MIXER
Key Video
Y and C
Key Video
with Border
What Color
CPU Data
Number
of Pixels
Number
of Lines
Amount
of Opacity
Key Signal
Key Signal
SUBTRACT COMBINE