SEL-1FS1/SEL-2FS1 and SEL-1XD1/SEL-2XD1
Installation and Operation Manual
Installation, Operation, and Specifications
© 2015 Imagine Communications Corp.
Proprietary and Confidential.
Version 2.8 | Page 64
Closed Captioning/Teletext
Based on input and output video standards, an XD1 module performs the following closed captioning
transcoding:
•
If the input and output video standards are the same, the module de-embeds the CC data and then
re-embeds the data on the output program stream without any transcoding.
•
If the input format is SD-SDI and the output format is HD-SDI, the module transcodes the analog CC
waveform, based on the EIA 608 standard from the SD input stream to ancillary packets based on
the EIA 708 standard.
•
If the input format is HD-SDI and the output format is SD-SDI, the module transcodes the CC
ancillary packets based on the EIA 708 standard from the HD input stream to analog waveform
based on the EIA 608 standard.
Although North America has dedicated standards for closed captioning of video (EIA-608 and 708), many
countries in Europe and elsewhere have not yet adopted formal standards. For these countries, closed
captioning is part of the DVB Teletext System as described in ITU-R BT-653-3. These specifications define
all Teletext Systems (A, B, C, D) used in the world and are also known as the World System Teletext
(WST). A Teletext system is made of several pages of various data information and CC data is described
in one these pages. System B is used in Australia, the UK, and Germany, among other countries.
Australian closed captions are inserted on line 21/334 in analog PAL broadcast signals, as per the ITU-R
BT-653-3. When analog PAL is produced or converted to SDTV (625 digital), a digitized version of the
closed captioning appears on line 21/334 (in the same way line 21 on NTSC signals is digitized and
appears on the line 21 of SD-SDI signals). The ITU-R BT-653-3 document proposed by Free TV Australia
indicates how to carry this CC data into the VANC area of SD-and HD-SDI signals by use of the SMPTE
334M VANC embedding protocol. For digital broadcasting, Australia intends to use the ETSI EN 300 472
standard that specifies the conveyance of ITU-R System B Teletext in DVB bit streams.
Setting Closed Captioning and Teletext
To make changes to the default CC and Teletext settings, use the
CC/TT Embed
and
CC/TT Embed Line
parameters from
Data EMB x > Closed Captioning/Teletext
. To verify the presence of embedded CC and
TT, see
Data DMB x
> Closed Captioning/Teletext > CC/TT Present
.
An XD1 performs the following Teletext transcoding:
•
If the input and output video standards are the same, the module de-embeds the TT data and then
re-embeds the data on the output program stream without any transcoding.
•
If the input format is SD-SDI and the output format is HD-SDI, the module transcodes the analog TT
waveform based on ITU-R BT.653-3 standard (system B only) from the SD input stream to ancillary
packets based on the Free TV Australia OP47 standard.
•
If the input format is HD and the output format is SD, the module transcodes the TT ancillary
packets based on Free TV Australia OP47 standard from the HD input stream to analog waveform
based on the ITU-R BT.653-3 standard (system B only).
