DVB Update: Service Information
Martin Gold
NDS
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DVB SI Update: Overview
What is Service Information?
Features of DVB Service Information
Specification Status and Developments
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DVB SI Update: What is SI?
Operates in conjunction with PSI
(defined by MPEG):
SI data provides information for:
• Automatic tuning to transport stream
• User Information for Service, “Event”, and
“Component” selection
PSI data provides information for:
• Configuration of decoder for selected Service
• DVB extensions for non-MPEG components
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DVB SI Features
Data structured as several “Tables”
Structures use “fixed format” for
essential data, and descriptors for
optional or variable-length data (similar
to PSI)
• Efficient data transmission
• Extensible while maintaining compatibility
• Support for “private” extensions
Can provide standard EPG data-stream
• “Look and Feel” determined by receiver
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software
DVB SI Model
Networks
Satellite
Cable
Terrestrial
Transport Streams
Transponder
1
Transponder
2
Transponder
3
Channel
1
Transponder
T
Channel
2
Channel
C
Channel
1
Channel
2
Channel
C
Services
Bouquet
Service
1
Service
2
Service
3
Service
S
Audio 1
Audio 2
Service
1
Components
Video
5
Data
Service
2
Service
S
Service
1
Service
2
Service
S
SI Features: NIT
Network Information Table
Identification of transmission as a member of a
group of multiplexes - “Network”
Network Name
Tuning parameters with support for various
delivery media
• List of additional frequencies for terrestrial
transmission
Designed for simple transcoding of transport
streams
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SI Features: SDT & BAT
Service Description Table
Identifies Service names and Service types
Linked Services
Pointer to MPEG Program in PSI
• Service_id = MPEG Program Number
Bouquet Association Table (Optional)
Groupings of Services
May convey “logical channel number”
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SI Features: EIT
Present/Following
• Information on current and next events
Schedule (optional)
• Up to 64 days ahead - ordered by service and
time
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Event Information
• Title, short description
• Start time & duration
• Content classification & parental rating
• Longer text description
• Information on components
SI Features: TDT,TOT, RST
Time and Date Table
• Transmission of current time for automatic
setting of receiver clock
Time Offset Table (optional)
• Transmission of time offset by zone - both
current, and next offset values, with date at
which next occurs
Running Status Table (optional)
• Mechanism for signalling status transitions with
greater timing precision
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Example EPG using DVB SI
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DVB SI Specification Status
October 95: Edition 1 ETS 300 468
January 97: Edition 2 ETS 300 468,
added
• Time Offset Table
• Multilingual and Unicode Support
• Extension to content description
• Support for DVB Subtitling
• Incorporated from SI Guidelines
– Private Data Specifier Mechanism
– Service Move
– Service bit-rate signalling
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DVB SI Specification Status (2)
January 98: V1.3.1 EN 300 468, added
• Support for Terrestrial transmission
• SI for recorded “partial” bitstreams
• Support for Data Broadcasting
Agreed additions for next edition
(V1.4.1)
• HD Video component description
• Support for AC-3 audio
• Use of Transport Stream Description Table
• PSI descriptor for Data Broadcasting
• Support for 6MHz terrestrial channels
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