SIST ETS 300 472 E2:2005

SIST ETS 300 472 E2:2005 is the Slovenian adoption of ETS 300 472 Edition 2, a European Telecommunications Standard produced by the EBU/CENELEC/ETSI Joint Technical Committee. It specifies how ITU-R System B Teletext, also known as EBU Teletext or World System Teletext (WST), is carried in DVB bitstreams. In practice, it is for broadcast systems that need Teletext to be transcoded to analogue Vertical Blanking Interval (VBI) or subtitles to stay accurately timed with video.

What does SIST ETS 300 472 E2:2005 specify?

SIST ETS 300 472 E2:2005 specifies the transport syntax and timing model for carrying ITU-R System B Teletext in DVB MPEG-2 transport multiplexes. The document is organized into Scope, Normative references, Definitions and abbreviations, Insertion of Teletext into the MPEG-2 transport multiplex, and a Teletext decoder model.

Clause 4 explains how Teletext data is wrapped into Packetized Elementary Stream (PES) packets and then into Transport Stream (TS) packets. Clause 5 gives a conceptual decoder model that the bitstream must satisfy so that decoding and VBI transcoding work with the intended timing.

What are the key requirements of SIST ETS 300 472 E2:2005?

SIST ETS 300 472 E2:2005 requires Teletext to be carried as PES data inside TS packets, with the Teletext stream identified in the Program Map Table (PMT) by a Teletext descriptor. In practice, multiplexers must signal the stream correctly in Service Information (SI) so receivers can find and decode it.

• Teletext service rate and purpose - The scope limits each Teletext service to a maximum data rate equivalent to 16 lines per field, so it remains suitable for transcoding into the VBI. That matters because the same stream must still fit legacy analogue Teletext paths.
• TS packet handling - Clause 4.1 permits only TS adaptation_field_control values "01" and "10". This constrains how payload is carried and helps keep the Teletext stream packetized in a predictable way.
• PES packaging - Clause 4.2 sets the stream_id to private_stream_1, requires Data_alignment_indicator = 1, and fixes the PES header length for streams identified by the DVB Teletext descriptor. It also requires the PES packet length to end on a TS packet boundary, which makes encapsulation and parsing straightforward.
• Stream identification and stream content - Clause 4.3 and 4.4 use data_identifier, data_unit_id, and data_unit_length to classify Teletext data. For descriptor-identified streams, only EBU Teletext non-subtitle data, EBU Teletext subtitle data, and stuffing are allowed as data_unit_id values.
• Teletext packet layout - The data_field carries reserved_future_use, field_parity, line_offset, framing_code, magazine_and_packet_address, and data_block. This is the part that preserves Teletext packet structure so the data can be decoded directly or mapped back to the VBI.
• Line timing and order - The line_offset values are restricted for EBU Teletext data_units, and packets are inserted in the same order as they should reach the Teletext decoder or VBI. That matters for subtitle timing and for reproducing the original Teletext line placement.
• Decoder timing model - Clause 5 defines Teletext access units, applies Presentation Time Stamp (PTS) to the first access unit after the PTS field, and gives buffer and transfer-rate assumptions for the target decoder model. This is what implementers use to match presentation time or VBI insertion time to the associated video.

What terms does SIST ETS 300 472 E2:2005 define?

SIST ETS 300 472 E2:2005 defines the key terms needed to describe the Teletext carriage model and its signaling.

• MPEG-2 - The document uses MPEG-2 to mean ISO/IEC 13818, with systems coding in part 1.
• section - A section is the syntax structure used to map service information into ISO/IEC 13818 Transport Stream packets.
• service - A service is a sequence of programmes under the control of a broadcaster and carried in a schedule.
• Teletext descriptor - This descriptor, defined in ETS 300 468, identifies streams that carry EBU data in the PMT.
• PES - Packetized Elementary Stream is the packet format used to carry the Teletext data before TS packetization.
• PMT - Program Map Table is the PSI table used to describe the elementary streams in a service.
• PTS - Presentation Time Stamp is the timing reference used for when an access unit should be presented or inserted into the VBI.
• VBI - Vertical Blanking Interval is the analogue video interval used for Teletext transcoding.

Who uses SIST ETS 300 472 E2:2005?

SIST ETS 300 472 E2:2005 is used by DVB broadcast engineers, multiplex operators, receiver designers, and Teletext or subtitle system integrators. They use it to signal Teletext streams in PSI/PMT, package Teletext into PES and TS packets, and verify that subtitles and Teletext pages are timed correctly against video.

It is also relevant to quality and interoperability testing, especially when checking compatibility with existing TV receivers that have Teletext decoders and when validating transcoding to the analogue VBI.

What changed in SIST ETS 300 472 E2:2005 from the previous edition?

The document history records a first edition in May 1995 and this second edition in October 1996. The history also records the second edition as the edition published in October 1996.

Which standards are used with SIST ETS 300 472 E2:2005?

SIST ETS 300 472 E2:2005 relies on these normative references:

• ISO/IEC 13818-1 (1994) - Provides the MPEG-2 systems coding used for TS and PES packet syntax.
• ETS 300 468 - Provides Service Information (SI), including the PMT and the Teletext descriptor used to identify Teletext streams.
• ITU-R Recommendation 653 - Provides the System B, 625/50 television system reference for the Teletext packet structure.
• EBU SPB 492 (1992) - Provides the Teletext specification for 625-line television systems that the data packet fields follow.

What does the SIST ETS 300 472 E2:2005 document contain?

SIST ETS 300 472 E2:2005 contains syntax tables for the PES_data_field and data_field, plus tables for data_identifier, data_unit_id, and line_offset. These tables are the core implementation reference for packet structure and permitted coding values.

Clause 4 also describes the TS packet format and the PES packet format, including the fixed header handling used for Teletext streams. Clause 5 presents a conceptual Teletext decoder model with buffer sizes, transfer rate, PTS handling, and timing rules for both transcoding and direct decoding.

For implementers, the document is mainly a packetization and timing guide. For testers, it provides the fields and constraints needed to verify signaling, alignment, subtitle timing, and VBI compatibility.