SC-03-07 meeting, Vienna, 2007-05

Report of the meeting of SC-03-07 Working Group on Audio Metadata of the SC-03 Subcommittee on the Preservation and Restoration of Audio Recording, held in Vienna, 2007-05-07

The meeting was convened by chair C. Chambers

The agenda and the report of the previous meeting, held on 2006-10-07, were accepted as written.

Development projects

AES-X071: Liaison with SMPTE Registration Authority
Project scope: to formalize a working relationship with the SMPTE Registration Authority
Assigned to: SC-03-07, Initiated: 1997,
Intent: Liaison, Target: Continuing
Current goal: Status report, Goal date: Continuing
M. Yonge reported that it had been clarified with the Chair of W25 that the AES could establish a class 13 dictionary entry within the metadata dictionary. This would be managed by the AES standards secretariat and published on the AES standards "Registered Values" area of the web site. The main advantage of doing this is that the UID's would be harmonised across the SMITE dictionary and any other origination's elements who are also registered within this dictionary.

AES-X098A: Administrative and structural metadata for audio objects
Project scope: To collect information on all metadata issues pertaining to digital audio objects and all aspects of the digital documentation of digital audio objects. This scope includes field structures to describe and provide access to the audio content contained in digital files. It includes transfer, preservation and restoration information.
Assigned to: SC-03-07, Initiated: 1999-12,
Intent: Standard, Target: 2006
Current goal: PWD, Goal date: 2006-10
Status: Sent to SC-03-07 for completion as AES-X134

This document was discussed in conjunction with the contribution from the EBU as this was also produced for project AES-X134. The two documents were compared superficially in the meeting. It would appear that these are approaching the requirements for AES-X134 quite differently. Additionally, with the advent of the contribution from SMPTE where RP210 V10 draft shows that algorithmically-produced XML tag generation is being proposed, it was felt that the requirements of AES-X134 needs to be reviewed.

AES-X114: Metadata review
Project scope: to study and report on the methods and techniques for attaching and implementing metadata through all aspects of interfacing real-time and file-transfer audio, including, where related to audio, other metadata related to other media. The scope includes metadata for professional recording, sound reinforcement, production, broadcasting, and transmission as well as the exchange of metadata and associated audio among different organizations. It also includes the development of techniques, such as UML, to aid the description of the relationships and flow of metadata requirements in an open and recognised way.
Assigned to: SC-03-07, Initiated: 2001-01,
Intent: Review, Target: Continuing
Current goal: Status report, Goal date: Continuing
Three documents were tabled, one from SMPTE and two from the EBU.

The first discussed was EBU Tech 3001, Metadata for non-tape based camcorders along with the EBU P/META output document. This work will be maintained by the EBU P/MAG group in the future. This document is effectively a "metadata set" that has links to show which items map into RP210 (the SMPTE metadata dictionary) and which also map into the P/META structure. Tech 3001 and RP210 were then discussed but some concern was expressed at that the mapping seemed rather approximate is some cases and it is the view of some at the meeting that mapping should be binary, either it maps or it does not. However, mapping across complete sets needs not exact provided it is clear which elements within the set has not been matched. The general view of the meeting was that individual metadata elements should either map exactly or not to avoid inconsistencies. A discussion ensued on how audio metadata structures should be constructed and the way systems may end up referencing the metadata dictionary.

It is understood that the EBU will also be working on media metadata sets and there could be more information by our next meeting.

The SMPTE metadata dictionary was then studied and "Class 13" registrations that have already been included were discussed. This document as freely available from the SMPTE web site and it is recommended that those interested in metadata study this further.

RDF (Resource Description Framework) information from W3C was introduced as a possible method of setting down the AES metadata structure.

AES-X134: Core audio metadata set and XML tag definitions
Project scope: "Develop a core audio metadata set and to study and produce a standardised set of XML tags, along with their definitions, that describes the core set of metadata to accompany professional audio when being transferred by file or streamed formats and define these within the SMPTE metadata dictionary."
Assigned to: SC-03-07, Initiated: 2002-09-23,
Intent: Report, Target: 2008
Current goal: PTD, Goal date: 2007-11
Status: PTD expected Contribution documents from the EBU along with the document from AES-X098A discussed above. Along with the new information from SMPTE showing a method of automatically generating XML tag names, we now have potential conflicting input to this project. Discussions ensued on the problems that could occur with the possibilities of having multiple XML tag names for the same metadata element. It was felt that it is important that a core set of audio metadata should be very well defined and then mapped into a class 13 SMPTE registration. Then anything that is AES compatible with this set will also be mapped and compatible with SMPTE as well. Additional elements can be added to the AES sets if required, but these need not also be registered with SMPTE unless there was a need. In this way the AES would maintain the management of the core XML tag names associated with their related UID's. The status of AES-X98B was stated as being in secretariat format.

In summary the feelings of the meeting was that the AES should develop its own core metadata set for professional audio exchange and register this with SMPTE in class 13. It was proposed that the scope should be modified to include the identification of the core audio set as well as producing XML tag names.

It was agreed that the chairman and the AES secretariat would hold a meeting to put together some draft proposals. Following that it was hoped that contributions could be gather on the reflector and a project group meeting could be held in New York to complete some of this work.

AES-X138: IFPI Liaison
Assigned to: SC-03-07, Initiated: 2003-03,
Intent: Liaison, Target: Continuing
Current goal: Status report, Goal date: Continuing
Status: To be retired in favour of continuing informal liaison. It was proposed that this formal project would be retired as this liaison would continue as an informal liaison process.


There is informal liaison with the EBU P/MAG group as at least one member of this group is also a member of that EBU group.

New Projects:

A new project was proposed last meeting by the chair of SC-03-06 to take the document AES-X98B and map this into the SMPTE metadata dictionary. This was agreed and a new project will be raised. This is still in secretariat drafting.

New business:

There was no new business.

The next meeting will be scheduled in conjunction with the AES 123rd Convention in New York in October 2007.
AES - Audio Engineering Society