AJA FS1 - Manual (Page 63)

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55 FS1 Installation and Operation Manual — 30.1 Closed Captioning Translator
30.1 Closed Captioning Translator
In Standard Definition (525i59.94) video, closed captioning data is encoded and sent
on line 21 of both fields, using a format defined by the Consumer Electronics
Association standard, CEA-608. This is traditionally called “line 21", “SD”, or “608”
captioning, and is used for analog composite, analog component, and serial digital
(SDI) video.
In High Definition video, closed captioning is encoded and sent as Vertical Ancillary
(VANC) packets in SDI video, using a format defined by the Consumer Electronics
Association standard CEA-708 (there is no equivalent for analog HD video).
This is traditionally called “HD”, “DTV”, or “708” captioning. The data formatting
and encoding for 708 captions is very different from the data contained in 608 (SD)
captioning, reflecting the added features and capabilities available with CEA-708
standard.
The FS1 UpConverter automatically translates incoming line 21 captions to CEA-
708 format and inserts the VANC packets into the converted HD video stream. This
is a complete translation from CEA-608 format to CEA-708 format (including the
embedded SD captions).
The FS1 DownConverters automatically intercept and reformat the SD caption data
in the incoming CEA-708 VANC packets, and outputs it on line 21 of the standard
definition outputs.
To pass closed captioning data to the outputs, parameter 31.1 must also be set to
“Pass.” The FS1 CrossConverters will reformat and pass any incoming CEA-708
VANC packets for the output frame rate.
30.1 Caption Xlator Description of Choices
Parameter Adjustments:
ON
OFF (Default)
When set to ON and using the UpConverter, the FS1 will automatically translate
incoming line 21 captions to CEA-708 format and insert the VANC packets into the
converted HD video stream. This is a complete translation from CEA-608 format to
CEA-708 format (including the embedded SD captions).
When set to ON and using the Downconverters, the FS1 will automatically intercept
and reformat the SD caption data in the incoming CEA-708 VANC packets, and
output it on line 21 of the standard definition outputs.
When OFF, translation is not performed.