LC2000/LC2000-IQ/LC4000/LC4000-IQ
RollCall Control Panel Channel Operation Screens
Issue 1 Rev 6
Page 153
© 2015 SAM
11.10.2 Multi-line WST
The unit can pass World System Teletext (WST) for SD and RDD-08 or SMPTE 2031 teletext
for HD. You can enable or disable teletext output and specify the input and output lines used.
Teletext covers World System Teletext (WST) subtitles, SMPTE RDD-08 and SMPTE 2031.
For WST and RDD-08, only subtitle information is supported or processed. SMPTE 2031
VANC packets may be teletext subtitles, non-subtitles, or inverted teletext.
WST is only supported in 625 input or output encoded signals. RDD-08 is only supported in
50 Hz HD video standards as a VANC packet with a Subtitling Distribution Packet (SDP)
payload. Teletext subtitle transcoding is supported from WST to RDD-08 by taking the
decoded bytes from the WST signal and inserting them into the payload within the SDP (see
below). Transcoding from RDD-08 to WST is only possible if the SDP contains valid subtitles,
which are extracted and encoded as an output WST signal.
Teletext pass-through
Teletext pass-through is possible if a valid input teletext subtitle is present and input and
output video standards are the same. For SD video that uses a large number of WST VBI
(where the VBI may have multiple lines of WST and 2 Timecode lines) the unit can
encode/decode/transcode up to 15 lines of WST. In up and down conversion applications, this
would use up to 3 RDD-08 (OP47) packets. RDD08 OP47 allows for 15 lines of WST to be
encoded. SMPTE2031 allows only 5 lines of WST to be encoded.
625 Input - 625 Output
You can select which input lines of WST are encoded on the output (see instructions for SD
VBI line setup below). For the lines selected the status of WST being detected on that line is
reported back.
The unit allows for up to 15 lines of WST to be selected on the input. If valid WST is detected
on the selected lines, they will be placed on the same lines on the output. The status for each
line will be reported back.
It is also possible to remap one WST origin line. In this case, select Allow WST remap. If valid
WST is detected on the line selected by “WST origin line” it will be put on the line selected by
the user control “WST output line”.
625 Input - HD Output
In applications where the video is upconverted, you can select which lines of WST are
encoded.
1.
If RDD08 (OP47) conversion is selected, then up to 15 lines can be encoded in the
RDD-08 packet. A maximum of 3 packets are allowed on the output, each with
individual line number controls. The number of output RDD-08 packets on the output
is decided by the number of valid WST lines decoded on the input. The first five WST
lines are encoded in the first RDD-08 packet, the next 5 in the second RDD-08 packet
and so on.
2.
If SMPTE2031 conversion is selected, then the first 5 lines selected on the input are
encoded in the 2031 packet. Each single WST line corresponds to one SMPTE2031
packet on the output. All packets will be placed on the same line selected by the user
control (see control Output Line All PKTs in the menu list). The Data Unit ID can be set
to Teletext, Non-Teletext or Inverted Teletext.
Note:
Only one WST origin line may be remapped
