MICROTRONIX DX-2200, Руководство пользователя

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DX-2200
– SD/HD-SDI Text & Graphics Inserter – User Manual
Page 43 of 103
Command Code Mode of Operation
GnnNm
For Graphic Field nn, set the justification mode. These commands use the field length
that is set separately by the SnnJmm command.
m = 0
No justification is selected
m = 1
Display the text string left justified in the field. If the string is longer than the field, it is
clipped at the right. If the string is shorter than the field it is padded with spaces at the
right.
m = 2
Display the text string right justified in the field. If the string is longer than the field, it is
clipped at the left. If the string is shorter than the field, the string is padded with spaces
at the left.
m = 3
Display the text string right justified in the field. If the string is longer than the field, the
field expands to fit the string. If the string is shorter than the field, the string is padded
with spaces at the right.
m = 4
Display the text string centered in the field. If the string is longer than the field, it is
clipped at the left. If the string is shorter than the field, it is padded with spaces before
and after to center it.
GnnJmm
For Graphic Field nn, set the field length to mm characters for justification. If the field
length is 0, justification is disabled.
4.8.1.9.11 L
OW
L
EVEL
G
RAPHIC
C
OMMANDS
The Low Level Graphic Commands provide an additional level of control over switching between the active
and spare overlay buffers and in rendering Graphic Fields. In certain situations the use of these commands
can provide fast update rates for the Overlay.
The Graphics Overlays of the DX-2200-TI-03 use two memory frame buffers. One of these buffers is the
active buffer that provides a video output that is mixed on top of the input video and the other is the spare
buffer where the next image is rendered when the text overlay is updated. In normal operation of the text
overlay, updating the output video requires rendering all Text Fields to the spare buffer, then exchanging the
two buffers and clearing the new spare buffer to prepare for the next update.
The Low Level Commands provide additional control of the process for cases where:
1) The time when the text overlay update becomes visible must be controlled more accurately than is
possible with the standard text overlay commands.
2) Faster updates are required, especially in cases when 2 or more text fields displayed but not all fields
need to be changed.
Table 11: Low Level Graphic Overlay Commands
Command
Code
Mode of Operation
Low Level Graphic Overlay Commands
GB
Renders the graphic fields of the active layer to the spare buffer, but the buffers are
not swapped. The video output does not change.