
GUIDE TO INSTALLATION AND OPERATION
XVP-1801 |
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closed captions will be embedded, in the HD outputs, within EIA-708-B packets as per SMPTE 334M. CC1
from NTSC field 1 is up-converted to DTV service 1, and CC3 from field 2 is up-converted to DTV service 2.
Figure 3.12
Video Output group – Meta tab
HD to SD Downconversion:
As described in EIA-708-B, closed captioning within an HD signal is embedded in the form of ANC packets.
The XVP-1801 extracts the NTSC CC bytes from within incoming EIA-708-B DTV closed captions, buffers,
and re-inserts the data within line 21 of the output SD signals. Processing is restricted to NTSC CC
information only.
The XVP-1801 also supports incoming EIA-608-B CC packets conforming to SMPTE 334M. However, EIA-
708-B packets have priority. If both are embedded in the source, the EIA-708-B packets are decoded, as
explained above, and the EIA-608-B packets are discarded. If no EIA-708-B packets are detected, EIA-608-
B packets are automatically extracted if detected.
Field 2 of closed captioning is also processed and encoded to provide V-chip rating.
HD to HD Cross-conversion:
EIA-708-B closed captions are detected at the input and re-inserted into the output HD signal conforming to
the selected output HD format.
SD Input/Output Config
sub-section
Line 21:
Specifies if line 21 (or line 23 in PAL) shall be considered as blanking or active video; this selection
affects
Close Caption
availability, controlled in the
Close Caption
sub-section of this tab (see above).
Depending on the settings and input/output selected, it also affects the output video, as shown in this table:
For SD Output:
Input Format Line 21 Status CC Insertion
Effect on SD Output
HD 60 Hz
Blanking
Off
Line 21 blanked, first active line is 22, image slightly downscaled
Auto
CC run-in on line 21, first active line is 22, image slightly downscaled.
Active
N/A
Line 21 has active video and may be resized.
SD 60 Hz
Blanking
Off
Line 21 blanked.
Auto
Input line 21 copied to output.
Active
N/A
Line 21 has active video and may be resized.
HD 50 Hz
Blanking
N/A
Line 23 blanked, first active line is 24.
Active
N/A
Line 23 has video and may be resized.
SD 50 Hz
Blanking
N/A
Line 23 blanked, first active line is 24.
Active
N/A
Line 23 has active video and may be resized.