Data Translation DT3162, Руководство пользователя

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Appendix C
52
CCIR Specification
This section describes the differences between what is defined by the
CCIR specification and what the DT3162 defines for both vertical and
horizontal signals.
CCIR Vertical Signals and the DT3162
Each frame of CCIR video contains 625 lines (312.5 lines per field),
575 total active lines, and 287.5 active lines per field. Field 1 (the odd
field) is dominant.
Figure 11 shows the relationship between the line numbers defined
by the CCIR specification and those defined by the DT3162 in a
vertical signal, as well as the transition between fields.
Note: To maintain field 1 dominance and not acquire half lines at
the top of field 1 and at the bottom of field 2, only 572 lines can be
acquired. If field dominance is not an issue or you do not care about
the half lines at the top and the bottom of the frame, you can
configure the DT3162 to capture 576 lines. This is accomplished by
changing the first active line from 47 to 45 and changing the frame
height from 572 to 576.