SC-02-12 meeting, Munich, 2009-05

Report of the meeting of the SC-02-12 Working Group on Audio Applications of Networks of the SC-02 Subcommittee on Digital Audio, held in Munich, Germany, 2009-05-08

The meeting was convened by chair R. Foss.

The agenda was agreed as written, with some amendments by Foss, which had been posted to the reflector. J. Grant indicated that he would like to add to the Liaison section, as did P. Nye.

The report of the previous meeting, 2008-10-04, was accepted as written. P. Treleavan indicated a minor error within the section AES-X075, where 'IEC 61883' had been incorrectly referred to as 'IEC 61882'

Open projects

AES-R10: AES standards project report - Use cases for networks in professional audio
Scope: to identify and clarify use cases for networks in professional audio applications for Recording , Live sound, and Installations

Current status: AES-R10 published; to remain open for updates.
Project intent: Review; Initiated: 2008-08-25
Target date for completion: 2013 Current goal: Status report
Target date for goal: continuing

Foss indicated that there would be a workshop, where various audio control protocols would be discussed, and in particular how these protocols addressed the types of scenarios provided in the AES-R10 report. AESSC Chair R. Chalmers pointed out that the report was placed in an Annex to the agenda, and that it was clearly still an 'open' project, where revisions to the report could be made.

Development projects

AES-X075: Liaison with IEC TC100 for IEC 61883
Scope: Prepare recommendations and assist the work of IEC TC100 regarding the development and maintenance of relevant parts of IEC 61883. Any assigned task group shall report project progress to SC-02-12 and shall ask SC-02-12 for its advice on content. Administrative review of the project shall follow AESSC rules.

Current status: Continuing
Project intent: Liaison; Initiated: 1998
Target date for completion: Continuing Current goal: Status report
Target date for goal: Continuing

J. Yoshio presented the TC100 liaison report. The latest edition of IEC 61883-6 is 2.0. IEC 61883-6 originates from the A/M protocol of 1394TA. Maintenance work on IEC 61883-6 follows maintenance work of the A/M protocol. There is a new channel assignment specification, IEC 62574. This standard will be referred to in the revised A/M protocol. TA 11 has been established within TC100. The title of TA 11 is "Quality for audio, video, and multimedia systems". This TA will start a new project concerning loudness issues, and speaker assignment. The resulting specifications will be referred to by the A/M protocol. Some proposals for A/M protocol 2.2 were indicated: there is a new application format transmission method, the Blu-ray transmission method, and there is an extension structure for other channels (up to 32 channels) beyond the basic 6 channel structure. Yoshio-san indicated that the liaison report slides would be uploaded to the document site.

AES-X101: Data Type, Properties, and Method Definitions for Audio Device Application Program Interfaces (API)
Scope: Define and publish recommended data types, properties, and methods for use in the control of common audio devices.

Current status: SC-02-12-G will consider application of x101 to x170

Project intent: Report; Initiated: 1999-12

Target date for completion: 2006 Current goal: PWD

Target date for goal: 2009-10

The application of this report to the x170 project was discussed within the SC-02-12G task group. X170 uses a generic data type for the transport of data, and thus the relevance of the AES-X101 report has not yet been investigated. It will be further investigated as XFN is implemented on further devices, and as the generic data type is matched to actual data types appropriate to various devices.

AES-X132: Synchronization of audio over IEEE 1394
Scope: to specify methods of audio clocking and sampling-frequency synchronization in a professional audio network based on the IEEE 1394 high performance serial bus. Include techniques to ensure devices function correctly in a network which includes IEEE 1394.1 compliant bridges

Current status: Awaiting Sec-formatted PWD
Project intent: Standard; Initiated: 2005-10
Target date for completion: 2008 Current goal: Sec-formatted PWD
Target date for goal: 2009-10

S. Harris reported that this was still a useful document, and hadn't undergone changes over the last 4 years. The working group agreed that it was important to publish the document, and M. Yonge subsequently agreed to complete the formatting of the document in time for the next working group meeting in New York.

AES-X137: Liaison with 1394 Trade Association (1394 TA)
Scope: Liaison with 1394 Trade Association (1394 TA)

Current status: J. Yoshio reported
Project intent: Liaison; Initiated: tba
Target date for completion: Continuing Current goal: Status report
Target date for goal: Continuing

Yoshio reported that a new liaison person, Peter Helfet, was appointed in April by the 1394TA to liaise with other interested groups, such as the AES. Yonge agreed to contact Helfet.


Liaison with AVB - M. Mora, the liaison with AVB was not present at the meeting. Foss agreed to provide the AVB task group site. Foss also agreed to contact Mora about future liaison work. U. Zanghieri reported on work to incorporate aspects of AVB related to synchronization and stream reservation, pointing out that it is not necessary to incorporate all aspects of AVB. J. Grant agreed to e-mail T. Jeffrey's address to Yonge, who agreed to contact Jeffrey about liaison with AVB.

Proposal - Liaison with ACN: P. Nye indicated that ACN is an ANSI standard - initially targeted at the lighting industry, but created with a wider scope. It has been adopted by an audio manufacturer for audio applications. ACN was created by ESTA, and Nye encouraged us to take up 'observer' membership of ESTA, and thereby track the status of ACN. Chalmers indicated that we would not need a formal liaison, but could simply report on status at each meeting. Nye said that he would be willing to provide a report for future working group meetings, and more immediately would direct us to a relevant site, and provide a brief report.

Liaison with MPEG - J. Grant reported on the possibility of a liaison with MPEG. The next MPEG meeting is on 1 July in London. There was a call for contributions, in particular transport of media and random access of content. Contributions are required by 12 June, and John has posted details on the SC-02-12 document area.

Proposal - Liaison with IEC 62379 - Grant also reported that the latest draft documents are on the document site. John provided a brief overview of the IEC 62379 architecture. This liaison is effectively covered by the current liaison with TC100.

There were no other liaison issues.

New Projects

R. Gurdan provide a brief overview of the SC-02-12-G task group meeting. He indicated that the meeting had perused the X170 draft standard document and had discussed various issues related to the standard. In particular, the issues of grouping and modification were discussed. The SC-02-12G meeting was a highly productive meeting.

The group proposed that there be a new project for the liaison with the Ethernet AVB.

New business

There was no new business.

The next meeting will be scheduled in conjunction with the AES 127th Convention in New York, NY., US., 2009-10.

AES - Audio Engineering Society