INTERNATIONAL ORGANISATION FOR STANDARDISATION

ORGANISATION INTERNATIONALE DE NORMALISATION

ISO/IEC JTC1/SC29/WG11

CODING OF MOVING PICTURES AND AUDIO

ISO-IEC/JTC1/SC29/WG11N1720

mpeg 97

July 1997 / Stockholm

Source:

Convenor of mpeg (iso/iec jtc1/sc29/wg11)

Status:

Approved by WG11

Subject:

mpeg Press & Public Release

Date:

25 July 1997

 

The Moving Pictures Experts Groups (MPEG) met for the 40th time, in Stockholm, Sweden, from 21 - 25 July 1997, at the invitation of the Swedish Information Technology Standardization (ITS). The meeting was organized by the Swedish Ericsson, Telia, and Teracom Corporations.

 

Highlights

MPEG decided that a second version of the MPEG-4 Standard will follow the first version, a year after completion of the first. This means that MPEG-4 version 2, which will be a superset of version 1, becomes International Standard in November 1999. Version 2 will be backward compatible with version 1, meaning that material coded for version 1 decoders can be played without a glitch on version 2 decoders.

 The objective of the second version is to add functionality to the first version. In the area of Video, the second version of MPEG-4 will add: scalable transmission of objects with arbitrary shape, support for (semi-)transparent video objects, tools for additional efficiency improvements. Extensions for Synthetic Audio will add spatial auralizations (making it sound like audio sources have an identifiable location in space) as well as taking into account the acoustic properties of different materials and the spatial manipulation of audio sources.

 MPEG received 7 responses to its Call for Proposals for the Identification and Protection of Content in MPEG-4. Together with the respondents, some of which with long standing experience in the field, MPEG is working on including methods for identifying owners and right holders of MPEG-4 encoded content. MPEG also works on methods for protecting the rights related to that multimedia content, as it feels that this is crucial to the success of the standard in the market place.

 The technical work during the meeting was, of course, dedicated to version 1 of the Standard, which will be moved to the relatively stable status of ‘Committee Draft’ in November this year. Text-To-Speech and Structured Audio were added to the Working Draft of the Audio part of MPEG-4. In Video, most of the activities were directed at getting a stable description. The Systems Group cleared many issues that are needed to present the different MPEG-4 objects in a synchronized and predictable way. Furthermore, a reference model was developed for the systems decoder, that models timing and buffering aspects.

 Preliminary embodiments of some of the MPEG-4 tools have been combined into a number of ‘MPEG-4 Multimedia Players’ and run as demonstrations. These showed to the meeting, in an exciting way, the power and flexibility of the MPEG-4 approach to sound, picture and data representation and manipulation.

 

Details

The remainder of this document gives more detailed information, organized according to the different subgroups.

 

Video

The MPEG-4 video group work was dedicated to finalizing the video technology for the Committee Draft of the MPEG-4 standard to be released in October 1997.

 Technology that is considered stable will be standardized in Version 1 of the MPEG-4 standard, while technology needing more testing and fine-tuning will be included in Version 2. Version 1 of the MPEG-4 Video standard supports texture and video coding, the coding of arbitrarily shaped objects, and error resilient coding of video streams.

 The emphasis of the meeting was on getting a well tested standard, which is done through a thorough bitstream exchange procedure. This means only small changes were made to the algorithms under development. The organization of the bitstream exchange procedure was one of the important tasks, while at the same time continuing the convergence of the current Working Draft with the two different software implementations used within MPEG.

 

 Audio

At the 40th meeting of MPEG, the proposals for MPEG-4 Structured Audio (SA) and Text to Speech (TTS) interface were approved for inclusion in the Working Draft. Furthermore, the relevant source code for both MPEG-4 SA and TTS has been provided, which means that all MPEG members can implement and test these tools.

Also in MPEG-4, the core experiments on audio scalable coding are progressing well. The scalable coders assessed, continue to show better performance than their individual components for a similar total bitrate and thus offer a more economical overall solution.

 

DMIF

The DMIF (DSM-CC Multimedia Integration Framework) Group completed the Working Draft document on DMIF. DMIF is part 6 of the MPEG-4 standard, that provides a consistent interface to the MPEG-4 Systems layer, while allowing access to remote interactive MPEG-4 terminals and/or broadcast and storage media.

The two main concepts are ingrained in DMIF are the global network unique Session ID and the channel association tag. The network Session ID can be used to tag resources and log their usage for subsequent billing, and the channel association tag can be used to thread an MPEG-4 elementary stream with its QoS through various networks in its path.

 The work on the DMIF part of the standard will from now on be carried out in the newly created ‘Delivery’ Group, which works on negotiating and setting up transparent connections over possibly heterogeneous networks. Note that MPEG will not define transport layers for MPEG-4, but will rather describe how MPEG-4 content can be carried over existing ones and those yet to be defined. MPEG also defines the interfaces to them.

The original ‘DSM’ Group (Digital Storage Media) will continue to exist, with its original mandate: interfaces to storage media like the DVD. MPEG believes the DVD to be a promising platform for usage of the MPEG-4 standard.

 

Systems

The Systems sub-group produced a release of the working draft of MPEG-4 systems, signifying major progress. Special attention has been paid to the Systems Decoder Model (SDM), the Scene Description Format (BIFS -Binary Format for Scene description) and the interface between the scene description and elementary streams (Objects Descriptors).

 Amongst the various improvements made during the meeting, SDM now adequately addresses the needs of broadcasting applications; BIFS (in addition to the description of basic spatio-temporal relationships between objects), provides for animation streams and the integration of 2D and 3D objects. Additionally, the scene description’s interface to elementary streams (the object descriptor mechanism), is now fully specified.

 Two new activities were introduced by Systems during this meeting:

 

Implementation Studies

As the CD (Committee Draft) approaches, the Implementation Studies sub group, not unsurprisingly, is increasing its effort towards analyzing the implementation complexity for MPEG-4 systems. The goal being to identify ways to reduce the implementation complexity of the standard without adversely affecting the functionality and quality that the market has come to expect from MPEG.

 The focus of the group during this meeting has been to address ways of ensuring high quality faithful real time reproduction of MPEG-4 content. MPEG-4 introduces some exacting processing requirements that decoders need to address, including computational resource allocation and synchronization issues. Closely associated with this analysis, the group has continued to make excellent progress in the field of computational graceful degradation and has specified the syntax required in video bit streams to adequately support the techniques under consideration.

 

Background information

Future MPEG meetings will be held in Fribourg, CH (October '97), San Jose, US (Feb ’98) Tokyo, JP (March '98), Dublin, IE (July '98), Israel (Nov. '98) and Korea (Mar. '99).

For further information about MPEG, please contact:

Dr. Leonardo Chiariglione, (Convenor of mpeg)

CSELT

Via G. Reiss Romoli, 274

10148 Torino, ITALY

Tel.: +39 11 228 6120; Fax: +39 11 228 6299

Email: leonardo.chiariglione@cselt.it

or refer to the MPEG homepage:

http://www.cselt.it/mpeg

The MPEG homepage has links to other MPEG pages, that are maintained by some of the subgroups. It also contains links to public documents, that are freely available for download to non-MPEG members.