LC2000/LC2000-IQ/LC4000/LC4000-IQ
RollCall Control Panel Channel Operation Screens
Issue 1 Rev 6
Page 152
© 2015 SAM
11.10.1 Closed Captions
Closed Captions covers CEA-608 and CEA-708 specified captioning. Although these
specifications support captioning in multiple video standards, CEA-608 is only supported in
525 input or output as a line 21 signal. CEA-708 is only supported in 59 Hz HD video
standards as a VANC packet with a Caption Distribution Packet (CDP) payload.
Closed Caption pass-through is possible if a valid input closed caption is present and input
and output video standards are the same.
Closed Caption transcoding is supported from CEA-608 to CEA-708 by taking the decoded
bytes from the line 21 signal and inserting them into the compatibility byte within the CDP.
Transcoding from CEA-708 to CEA-608 is possible if the CDP contains a compatibility bytes,
which are extracted and encoded as an output line 21 signal.
Closed captions are automatically detected in the input video, and the detected format shown
in the Status window. For closed captions to be embedded in the output video, they must be
enabled. User control for on which line to embed CEA-708 is provided, but CEA-608 is always
fixed at line 21.
11.10.1.1
CEA608/708
•
CEA-608/708 Output Enable:
Enables embedding of CEA-608 captioning as a line
21 signal in 525 output video, and CEA-708 captioning as an embedded VANC packet
in 59 Hz HD output video.
Note: The Output Enable controls only enable embedding of output closed captioning.
For closed captioning to be present in the output video, valid input closed captioning
must be detected, and you must select the correct output standard to support
pass-through or transcoding.
•
Output Line:
Selects the output line on which to insert CEA-708 VANC packets. The
range is from line 8 to line 20 in one-line steps. The default is line 10.
•
CEA-708 Output Line Status:
Shows the actual output line number on which
CEA-708 VANC packets are inserted. If no line number is selected, “OFF” is
displayed.
Note: If the line selected is already in use, the VANC embedding hierarchy will place
the CEA-708 packet on the nearest available line.
11.10.1.2
Input Status
The Input Status box shows if either CEA-608 or CEA-708 captions are detected on the input.