In this series of five articles, prominent members of the EBU/SMPTE Task Force describe the work carried out by the Task Force in pursuit of “Harmonized Standards for the Exchange of Programme Material as Bitstreams”.

The articles have been derived from presentations given by the Authors at IBC ‘98 in September. Many thanks must go to Roger Miles and Myrianne Jansen of the EBU Technical Department for converting the audio tapes recorded at Amsterdam into word-processor text files.

Future television production systems are going to be far more complex than anything we've dealt with in the past. Thus, in order to pull together all the various dimensions of what the EBU/SMPTE Task Force had set out to do, it created the Systems subgroup specifically to concentrate on matters relating to system integration.

This article describes a system model for television production operations, based on the transfer of bitstreams within a distributed studio object environment. It puts forward a migration strategy and also describes a different economic model for equipping television production facilities in the future.

The Compression subgroup of the Task Force was set up to provide guidance for the longterm integration of compression into programme production. Its work led to the conclusion that there is no single member of a compression family that satisfies the requirements of a fully-networked digital production facility.

The two compression families ultimately selected by the subgroup were MPEG and DV, each of which offers individual trade-offs in terms of coding flexibility, product implementation and system complexity. This article gives an overview of the factors which led to this choice.

The Networks and Transfer Protocols subgroup of the Task Force had the responsibility of finding the best technologies to enable different data types to be moved around a networked production environment. It had the task of identifying the best methods for (i) audio/video streaming in real-time (and faster than real-time), (ii) file transfer (also at different speeds) and (iii) file access.

The chosen methods should guarantee the interoperable transfer of programme content between devices, and these transfers should meet the high-end requirements of the TV broadcast world. An additional part of the subgroup’s work was to identify and define the further work that needs to be carried out by standardization organizations.

In July 1997, the Technical Module of the DVB Project set up an Ad-hoc Group on Digital Satellite News Gathering (DSNG) under the chairmanship of the RAI. Its tasks were: (i) to define the specification of the modulation/channel coding for DSNG and other contribution applications by satellite, (ii) to define the specification for the auxiliary co-ordination channels and (iii) to co-operate with other DVB groups in order to define the user guidelines for source coding, Service Information (SI) and scrambling for Conditional Access (CA).

A flexible DVB-DSNG system has now been defined and is described here. Mainly based on the DVB system for satellite broadcasting (DVB-S), it offers a range of different picture-quality levels at various bit-rates by using the MPEG-2 MP@ML and 422P@ML algorithms. The specification for the auxiliary co-ordination channels was finalized by the group in Autumn 1998 and the approval procedure is still in progress within DVB and ETSI. It is not described in this article for reasons of conciseness.

In October 1997, the EBU carried out tests to verify the interoperability of MPEG-2 MP@ML satellite news-gathering equipment from various manufacturers – under operational conditions via an 8.448 Mbit/s satellite channel.

A report on these tests was published by the EBU in July 1998 and this article is based on that report.