beautypg.com

Vbi user data, Vbi in pid, Teletext extraction – TANDBERG E5714 User Manual

Page 22: Data channels, 4 data channels

background image

Introduction to the Basic Encoder

Page 1-14

Instruction Manual: evolution 5000 E57xx DSNG and DENG Voyager Encoder

ST.TM.E10076.3

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 (EBU and SMPTE)

·

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 7-24 and 319-336 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.
Line filters can be invoked to selectively disable any individual lines in this

range. The filters are provided to allow the user to ensure that

non-Teletext lines (e.g. ITS lines) are not erroneously extracted. The

extracted Teletext lines are formatted into PES packets according to the

DVB specification. The Teletext PES packets are time-stamped to allow

correct alignment of subtitling captions with decoded video.
The following Teletext services are extractable:

·

Sytem B (WST) Teletext

·

Video Programming Teletext (VPT), PDC (Packet 8/30 format 2)

·

Inverted Teletext

1.3.4

Data Channels

The basic Encoder supports two data channels, an asynchronous RS-232

and a synchronous RS-442. These are provided as data pipes only, they

are not time-stamped.

This manual is related to the following products: