SC-02-12 meeting, San Francisco, 2012-10

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 San Francisco, 2012-10-28

The meeting was convened by chair R. Foss.

The agenda and the report of the previous meeting, 2011-10-22, were accepted as written.

Open Projects

AES58-R: Review of AES58-2008: AES standard for digital audio - Audio applications of networks - Application of IEC 61883-6 32-bit generic data
Discussion: Foss indicated that this could be applicable to the streaming of control data (apart from MIDI) over IEEE 1394, and that the standard was complete. It would also be of relevance to Ethernet AVB.

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

Discussion: Task group SC-02-12-J was established to work on this report. N. Brock had updated the report with edits and information relating to telematics use cases. M. Daniels agreed to search for any further updates that Brock might have made to the report. K. Gross agreed to look at the report and possibly update it further. The goal is to have approval for a version of the document by the next AES meetings in Rome.

AES-X075: Liaison with IEC TC100 for IEC 61883
Project 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.

Discussion: J. Yoshio provided a liaison report that contained an IEC standards update and described work done on TC100 specifications related to SC-02-12.

1. IEC standard update -
     a. IEC 61883-6 (A/M Protocol) Edition 3.0 status - the 3rd revised version of the CDV is circulating. Closing date of voting is 2012-11-09. Richard Foss will request that this edition be put onto the working group document site.
     b. IEC 61883-8 Edition 1.0 Amendment 1 status - the CDV is circulating. Closing date for voting is 2012-11-30
     c. IEC 61883-1,2,3,4,5 and 7 status - the stability date of all other parts is 2013-05 or 2014-03. They will be reviewed.
2. TC100 liaison with IEEE 1722 - TC100 plenary meeting was held from 22 to 26 October in Berlin. TC100 approved the request to establish the liaison between TC100/TA4 and IEEE1722 regarding AVB and IEC 61883 series. The liaison letter will be sent to IEEE. The need for this liaison has been recognized by those concerned.

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

Discussion: Yoshio is currently our liaison with the IEEE 1394 Trade Association and his report for AES-X075, in particular the IEC standards relates to work in the 1394TA

AES-X170A: Integrated Control, Monitoring and Connection Management for Digital Audio and other Media Networks
Project Scope: The objective of this project is to create and standardize: 1. A set of structured Internet Protocol-based messages that can be used to control single parameters or groups of parameters, and to monitor these parameters. The parameters are associated either with typical signal processing functionality within audio devices, synchronization between such devices, or connections between such devices. 2. A mechanism for grouping of device parameters, and messages required to implement such grouping. 3. A mechanism for the control of latency within networks of audio devices, and a specification of the messages and parameters required for the control of such latency. 4. Parameter modifiers, and the messages required to create and configure such modifiers. 5. Security levels, and the messages required to set and get such levels.

Discussion: Foss indicated that there had been no further comments on the secretariat-formatted draft standards document. There were also no further comments in the working group. M. Yonge proposed that the document therefore progress to the public 'Call for Comment' stage. There was some discussion relating to the name of the standard.

AES-X170B: AES standards report - supplementary information on AES-X170A, 3CIM
Project Scope: The objective of this information document is to present additional tutorial information pertaining to particular aspects of the X170 specification, in particular: 1. The origins of the 7-level hierarchy. 2. The creation and processing of X170 messages. 3 Peer to peer grouping and master/slave grouping of device parameters. 4 Modifiers. 5. Deskitems.

Discussion: Foss agreed to edit and possibly update the report and send it to the secretariat.

AES-X192 High-performance streaming audio-over-IP interoperability
Project Scope: 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.

Discussion: K. Gross, the task group leader, presented a report of the proceedings of the task group meeting that was held on the previous day. He indicated that a number of comments on the draft document were discussed, in particular relating to:
• Media Profile - there is further work to be done on this. It is a normative annex at present;
• Control protocol - decision was made to not make any recommendations regarding this;
• Transport buffering - not time to deal with this.
Remainder of the meeting was spent going through the draft up till clause 6.

A request was made for the working group to peruse the clauses agreed by the task group. Comments should be made on the reflector.

AES-X210 Open Control Architecure
Project Scope: To specify a scalable control-protocol architecture for professional media networks. The initial version will address audio aspects only, but it is intended ultimately to expand the scope to video through collaboration with a video-oriented standards body such as SMPTE. Note that OCA is a control protocol only, and does not aspire to provide streaming media transport. It is intended to cooperate with all kinds of media transport architectures.

Discussion: J. Berryman, the task group leader, was not present at the meeting. Yonge indicated that task group SC-02-12-L has been set up to handle this project's writing tasks, and that the initial documents are on that group's document site. Foss indicated that he would request a report of the initial task group meeting from Berryman.


Liaison with Ethernet AVB: M. Mora, who leads this liaison, was not present at the meeting. Foss indicated that version 21 of the IEEE 1722.1 specification was the current version and that he would ask the editor, J. Koftinoff, whether a copy of the document could be placed on the working group document site.

Liaison with MPEG: J. Grant was not present at the meeting. Foss indicated that he would request John for a liaison report.

Liaison with IEC 62379: P. Stevens was not present at the meeting. Foss indicated that he would request Peter for a report.

Potential Liaison with AVNU: There was a request relating to relating to AVB layer-3 streaming. Gross indicated that he was in contact with AVNU and would request documents relating to this when they are complete. He also indicated that Annex B of the X192 project spec, relating to layer-3 streaming between AVB and X192 devices, had been shared with AVNU. Annex C, relating to synchronization, is not yet complete.

New projects:

There was discussion relating to the transport of AES3 over IP networks. S. Heinzman indicated that there was a mechanism for doing this using Ravenna networks. There is already a method for transport of AES3 over AVB using an IEC 61883-6 format. The transport of AES3 using RTP would probably use similar formatting. It was proposed that a new project should be created for this purpose.

New business:

There was no new business.

The next meeting will be scheduled in conjunction with the AES 134th Convention, in Rome in May 2013.

AES - Audio Engineering Society