SC-03-07 meeting, New York, 2007-10-07

Report of the meeting of the SC-03-07 Working Group on Audio Metadata of the SC-03 Subcommittee on the Preservation and Restoration of Audio Recording, held in New York, 7th October 2007.

The meeting was convened by chair C. Chambers The agenda and the report of the previous meeting were accepted as written. It was noted that the text of the current scope for AES-X098 applies as an overall scope for the set of output documents, however each document now needed a specific scope to clarify its content.

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

Status: M. Yonge reported that the AES had now applied for a class 13 entry in the SMPTE metadata dictionary (RP210) and this application was raised at a SMPTE meeting two weeks prior to this meeting. The AES hopes to hear of the progress of this application in the near future.

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

It was noted that this document contains descriptive metadata and the document scope should be edited to reflect this.

This document was discussed in conjunction with the model that was tabled as a contribution from the EBU last meeting in Vienna. The two documents were discussed in the meeting. It was thought that the EBU document was an output from the P/MAG working group and they proposed to produce a reference XML implementation from this work. However, as no member of the P/MAG group was present when the EBU document was tabled, it was not clear what the EBU would like to do with this. However, it was understood to be a contribution to AES-X134 and is largely based on an extended Dublin Core.

The meeting discussed what should be done with AES-X098A? Should the AES publish it or should this be merged with the EBU model in some way? There was also discussion around the question of if the AES is the correct organisation to publish descriptive metadata as this could be left to other within their respective areas on the industry to do this.

Should the AES limit itself to the technical metadata only? It was thought that this document should be turned into an information document to contribute to Audio / Video standards elsewhere including the EBU.

It was proposed to hold a formal meeting between the EBU (P/MAG) and AES maybe in Amsterdam next May. However, it was thought that a set of questions along these lines should be put in advance to enable action to be agreed next May.

  • What does the EBU expect of the AES in this area?
  • Do they consider their proposal complete?
  • Do they see a conflict if the AES registers item in RP210 in their class 13 node and the EBU does the same?
  • If they do see the possibility of conflicts arising, how will they be resolved?

It was noted that there was a great deal of audio metadata in the SMPTE's base metadata dictionary (RP210). The question of what happens when there is duplication of the audio metadata in the base dictionary and a class 13 node. It was pointed out that this could happen if the description of a particular entry in the base dictionary was not sufficiently detailed (or contextualised) for a particular branch of the audio industry. Under these circumstances, a duplicate class 13 entry with more suited and detailed description to suit particular workflows could be made. Then any process could reference either entry depending on the context it was being used. Action point. Set up meeting with the EBU in Amsterdam during the next convention.

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

For information: RDF (Resource Description Framework) was in use within the BBC archive database (Infax) to enable linking of metadata from this to other structures.

There was a general concern at the lack of technical and administrative metadata in many publications. It is hoped that the publication of AES-X98 documents from SC-03-06 will provide the necessary detail for our industry.

It was reported that a good deal of work has already been done on linked schemas and this group should study this further. It was hoped that this could be discussed during the next meeting.

A general discussion then took place on the number of approaches to the inclusion of alternative references to media objects. This had been raised a few years ago and had been referred to as the "Also Known As" (AKA) structure. It was generally recognised that as file base storage of media becomes prolific, the tags, unique IDs or names that media is labelled with will also expand. It was likely that the same media object will be referenced by different labels in other parts of our industry and almost certainly will have a different label applied in different industries. It was thought that having a method of applying an AKA history in some form will help maintain the linking of media and metadata to it's origins as well as prevent the build-up of duplication within large media libraries over time.

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

This area links with the AES-X098A discussion above. It was agreed that the wording in the scope of this project needs to be adjusted to read "core metadata for audio exchange" rather than "core audio metadata set".

The meeting discussed how the RP210 dictionary could be used between different areas of our industry.

The meeting then discussed the work that the standards manager and the chairman of this group had carried out in July to draft an AES policy document for dealing with metadata. The draft document was posted to the group. The key elements of this document were discussed.

It was hoped that the draft document will be published as a report from this group (as an output of AES-X114) and once this has been reviewed the chair of the SMPTE group, (was done with a minor revision) this document will be reformatted as an AES report. However, as this had a more general application across the AES, the chairman of the standards committee requested that a more formal approval be sort from other areas of the AES before it is made publicly available.

It was suggested that this group should also produce guidelines for implementers to aid the application of any agreed AES metadata policies.

It was also noted that SMPTE are in the process of adding XML tag names to the Metadata Dictionary entries. A SMPTE draft of RP210 was produced and shown at our last meeting demonstrating these. It was confirmed that the automatically generated XML tags will be added to the dictionary in the near future.

It was then suggested that if the SMPTE class 13 AES registration could be processed quickly enough, this reference could be added to the AES-X098B document before it is published as this contains XML tag names specific to that proposed standard.

There was a discussion about the need to compare the EBU proposals administrative metadata and AES-X098A to provide output and complete the work of this project. It is hoped that a simple table will be built and shared.

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:

The new project proposed last meeting will be raised to link the AES-X098B document with the class 13 registration of the SMPTE metadata dictionary. It was agreed that this work continue as discussed earlier in the meeting.

New business:

There was no new business.

The next meeting will be scheduled in conjunction with the AES 124th Convention in Amsterdam, 2008-05.

AES - Audio Engineering Society