SE4000 MPEG-2 Contribution Encoder
VBI Data Transmission
01-0934-401-B
B-1
VBI Data Transmission
B
The Tiernan SE4000 and the latest series of Tiernan decoders, such as the TDR60, can be
configured to transmit various types of Vertical Blanking Interval (VBI) data when it is present in
the input video.
The following encoders and decoders support one or more methods for transmitting VBI data:
•
SE4000 and TE6000 – software V2.21 or later
•
TDR60 – software V4.10 or later
A standard NTSC TV signal consists of 525 horizontal lines, referred to as a frame. Each frame is
divided into two fields, each with 262 ½ lines. The first 21 lines of each field are the VBI region;
the remaining lines contain the active video picture.
A standard PAL TV signal consists of 625 horizontal lines, referred to as a frame. Each frame is
divided into two fields, each with 312 ½ lines. The first 22 lines of each field are the VBI region;
the remaining lines contain the active video picture.
For standard NTSC and PAL video encoding, the first 6 lines of the VBI region contain vertical
timing pulses. VBI data is not allowed on these lines, however the remaining lines in the VBI
region are available to carry any type of data.
B.0 MPEG and VBI
Typical forms of data included in the VBI of broadcast video transmissions are World System
Teletext (WST), VPS, WSS, NABTS, Closed Captions, XDS, AMOL, Vchip, and VITC. Originally,
the MPEG video compression scheme discarded all VBI information and included only the
compressed, active video portion of the picture for transmission. This caused all VBI data to be
lost when the video was digitally compressed for transmission using MPEG. Today, however,
enhancements to the original MPEG compression system have provided two methods for
including VBI data in digital-compressed MPEG streams:
•
The first method is to extract the data from the baseband video input and insert that data
digitally into the transport stream as either a dedicated PES stream on a dedicated PID,
as in DVB-Teletext, or as an extended data field in the video frame header information as
in ATSC-CC.
•
The second method is to shift, or expand, the active video portion of the picture to include
the VBI lines in the compressed picture frame, as in DVB 4:2:2 expanded windows.
For either of these methods to work, it is required that both the encoder and decoder are:
•
Functionally capable of processing the required video.
•
Correctly configured, either manually or via auto-sensing functionality, for the employed
VBI method.
All of the VBI schemes described in this document, with the exception of Tiernan Proprietary
Closed Captions, adhere to industry standards and formats, defined either by ATSC or DVB.
Tiernan Radyne ComStream equipment does inter-operate with all other vendor’s equipment that
is found to be compliant with these industry standards.
Summary of Contents for TIERNAN SE4000
Page 2: ......
Page 12: ...Preface SE4000 MPEG 2 Contribution Encoder xii 01 0934 401 B...
Page 103: ...Configuring the SE4000 SE4000 MPEG 2 Contribution Encoder 5 6 01 0934 401 B...
Page 115: ...Troubleshooting SE4000 MPEG 2 Contribution Encoder 6 12 01 0934 401 B...
Page 117: ...Maintenance and Software Upgrades SE4000 MPEG 2 Contribution Encoder 7 2 01 0934 401 B...
Page 121: ...Technical Specifications SE4000 MPEG 2 Contribution Encoder A 4 01 0934 401 B...
Page 141: ...Conditional Access SE4000 MPEG 2 Contribution Encoder C 12 01 0934 401 B...
Page 161: ...Glossary SE4000 MPEG 2 Contribution Encoder GL 12 01 0934 401 B...