SC-02-12 meeting, New York, 2009-10

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 New York, 2009-10-11

The meeting was convened by chair R. Foss.

The agenda and the report of the previous meeting held in Munich, 2009-05-08, were accepted as written.

Open projects

Review of 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

Project intent: Review; Initiated: 2008-08-25; Target date for completion: 2013
Current goal: Status report; Target date for goal: continuing

No action requested or required

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.

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

J. Yoshio presented amendments that had been proposed for the 1394TA AM protocol, from which the IEC 61883-6 standard derives. In particular he discussed the need for channel assignment and channel naming amendments with a view to transmitting multi-channel Blu-ray audio using IEEE 1394. Yoshio-san agreed to make his presentation available on the SC-02-12 document download 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.

Project intent: Report; Initiated: 1999-12; Target date for completion: 2006
Current goal: Status report; Target date for goal: 2009-12

R. Gurdan reported that this would be a useful report, but was not necessary for the X170 project. K. Gross indicated that he was not in a position to do further work on the document, and that there had been no requests for updating the document. The meeting proposed to retire this project.

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

Project intent: Report; Initiated: 2005-10; Target date for completion: 2008
Current goal: Sec-formatted PWD; Target date for goal: 2010-01

Awaiting Sec-formatted PWD. It was proposed to change the intent of this project to a report, not a standard, to simplify the formatting requirements.

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

M. Mora reported on AV/C activities relevant to the group. He indicated that AV/C over IP had been approved. The Music Subunit has not yet been finished, and the Audio Subunit is not expected to change. Foss indicated that he would contact the 1394TA liaison officer, P. Helfet, for a full liaison report.

AES-X170 - Integrated Control, Monitoring and Connection Management for Digital Audio and other Media Networks
Gurdan, X170 task group leader, relayed the activities of the X170 project in SC-02-12-G. The project is concerned with the standardization of the X170 protocol - "Integrated Control, Monitoring, and Connection Management for digital audio and other media networks". The X170 specification has been updated and is on the SC-02-12 group document site as x170-rjf-ptd-090930.pdf.

Gurdan indicated that there had been a secretariat request to reduce the size of the current X170 specification, and create two documents, a short and precise standards document and a separate informative tutorial document. Work will proceed on this.


Liaison with AVB
Mora, our liaison for AVB, gave an informative presentation regarding the status of AVB. In particular he outlined the status and issues around the three active projects - 802.1AS (timing and synchronization), 802.1Qat (stream reservation), and 802.1Qav (forwarding and queuing). He also discussed the IEEE 1722 layer 2 transport protocol, and a newly formed IEEE 1722.1 project whose goal is to resolve control and service discovery issues. Mora has agreed to upload his presentation to the SC-02-12 document site.

Liaison with ESTA
P. Nye indicated at our last meeting that he would be willing to provide a report on ESTA activities, in particular with relationship to ACN. Foss indicated that he would contact Nye for a report.

Liaison with MPEG
J. Grant reported on a possible liaison with MPEG. Grant was unfortunately not able to attend the meeting, but did report in a reflector email before the meeting. He has uploaded a relevant file, MPEG-29n105211-liaison.doc to the document site.

New Projects:

It was decided not to initiate a new project for Ethernet AVB, but rather to obtain information from the AVNU project.

Gross proposed a project for interoperability between devices streaming audio over Internet Protocol (IP). The goal is to standardize the format for audio data within IP packets. Currently there are a number of ways of transmitting uncompressed audio over IP. There are even a number of ways of transmitting audio using RTP. Gross has agreed to write a project proposal for this. The intent of this project would be a standard.

New business

There was no new business.

The next meeting will be scheduledin conjunction with the AES 128th Convention in London, UK., 2010-05.

AES - Audio Engineering Society