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V1682OPMA.doc
17 February, 2005
6. VIDEO PROCESSING
6.1 V
IDEO
P
ROCESSING
O
VERVIEW
Video passed through the V1682, other than the on screen display keying, encounters very little
processing. However the vertical blanking interval, and ancillary data space may be independently
blanked, and EDH may be inserted. These controls are available irrespective of on screen display
insertion.
6.2 VBI
B
LANKING
Data on vertical blanking interval lines can be blanked if necessary. VBI blanking may be enabled
disabled using the
ENG’ING > VBI
control which has the option
Pass
and
Blank
. When the unit is
set to blank the VBI, the blanking only applies to the active part of the digital line, ancillary data is
untouched.
The
VBI
control blanks all lines in the vertical blanking interval, there is no ability to blank only some
lines.
Lines which are blanked :
Format VBI
Lines
525/60
1 to 20 & 264 to 282
625/50
624 to 6 & 311 to 318
6.3
A
NCILLARY
B
LANKING
The ancillary data space may be blanked if necessary. This is especially useful when it is desired to
multiplex audio onto a group which is already occupied. Blanking when applied, clears all data
between EAV and SAV, the removal of single audio groups is not possible. Any other data in the
ancillary blanking space will also be lost.
Ancillary blanking can be enabled and disabled with control
ENG’ING > ANC Data
, which has two
options ‘
Pass
’ and ‘
Blank
’.
6.4 EDH
I
NSERTION
The V1682 by default inserts EDH into the outbound video. If EDH is already present, it is
overwritten. If EDH is not desired, it may be disabled with control
ENG’ING > O/P EDH
. There are
only two options for this control – ‘
EDH On
’ and ‘
EDH Off
’.
Note – EDH is inserted at the last point in the processing chain, so EDH will be correct whether or
not the on screen displays are on.
