TANDBERG Voyager E5784, Справочное руководство

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Introduction to the Basic Encoder
Reference Guide: Voyager E5784 and E5788 HD DSNG Encoder Page 1-11
ST.RE.E10137.3
VBI in Picture
By selecting the VBI in Picture extended active picture format available in
the MPEG 4:2:2 specification the Encoder compresses and transmits the
VBI data as part of the active picture. This mode requires up to 3 Mbit/s of
extra bit-rate, depending on the amount and complexity of the VBI
present.
NOTES…
1.
VBI in Picture transmits the VBI waveform as part of the picture and as such will be subject to
some distortion. Most analogue VBI types are robust against this type of distortion but others,
e.g. video index, are intended for SDI transmission and will not survive MPEG coding/decoding
in VBI in Picture mode. VITS test signal and ghost cancellation signal will become corrupted.
2. VBI in Picture is not supported when 3:2 Pulldown is active.
VBI User Data
Closed Caption data, together with other formats such as VITC and AFD,
can be transmitted in the user data field of the video or relevant part of
the video stream.
VBI in PID
The Encoder has the ability to extract and transmit a wide variety of VBI
line formats. Circuitry on the front end of the equipment incorporates a
number of general purpose line grabbers so that known formats of VBI
data can be extracted.
The following VBI data formats are supported:
•
Line 21 (field 1 and field 2) data Services EIA-608 (Closed Caption and
V-chip)
•
Neilson AMOL 1, Neilson AMOL 11
•
VITC
12
(EBU and SMPTE)
VITC extraction from line 16 or 22 for 625-line systems (EBU
definitions), or line 14 for 525-line systems is supported.
•
Programme Delivery Control (PDC), via ITU-R system B Teletext
extension data packets of type 8/30, format 2 and Line 16 Video
Programme System (VPS). Video Programming Teletext (VPT) and VPS
are trade names
•
Wide Screen Signalling (WSS) (line 23) ETS 300 294
•
Video Index (for Pan Scan, Aspect Ratio and Active Format Descriptor)
•
The supported VBI line number range is 10-22 and 272-285 for 525
lines and 6-22 and 318-334 for 625 lines
Teletext Extraction
The Encoder supports internal Teletext data extraction (Teletext drop)
from the VBI of a video input and formats this data into a transport
packet, as specified in the DVB specification EN300-472. The Encoder can
extract up to 18 lines of Teletext from each field of the video frame.
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VITC: Only timecode is extracted.