SC-02-12 meeting, New York, NY, 2019-10

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, NY, 2019-10-18.

The meeting was convened by chair Morten Lave.

The formal notice on patent policy was read.

The report of the previous meeting, held in Dublin, Ireland, 2019-03-22, was approved as written.

The agenda was approved as posted

In attendence were Paul Treleaven, Richard Cabot, Bruce Olson, Jim Meyer, Matt Mora, Morten Lave, Kent Terry, Terry Holton, Bob Lee, Gints Linis, Simon Jones, Jeff Berryman, kenneth Fause*, Kevin Gross*, John Grant*, Anthony Kuzub*, (* denotes by electronic link)

Projects assigned to this group but not mentioned here had no action requested or required - see for details.

Open Projects:

AES67-R - Review of AES67-2018 , AES standard for audio applications of networks - High-performance streaming audio-over-IP interoperability
The SC-02-12M task group met the day before this meeting, they are just getting started on some significant revisions to the standard.

The status of AES67-R is changed to "revising standard".

AES-X238 Media network directory architecture
The intent of this group was changed from producing a document to producing a standard. It will be a standard specifying what is needed or required and not how to make it.

The target is to be ready for the formal processing by the end of 2019. A new standards number (AES74) has been assigned.

AES-X242 Streaming audio metadata over IP
The SC-02-12-R group has held roughly bi-weekly calls this year, with several regular participants, and has completed a first internal draft of AES-X242. The group has been focused on use cases and requirements that can be used to validate the draft and help complete remaining sections. The current draft references SMPTE ST 2109 which has now been published by SMPTE.

SMPTE has continued discussions on the ST 2110-41 "Fast Metadata" project, which as previously reported has considerable overlap in goals with the AES-X242 project. As AES rapporteur to the SMPTE 32NF60 SVIP group working on FMX, the SC-02-12-R chair has provided input to the SVIP group and facilitated feedback from SC-02-12-R in the interest of maintaining AES-X242 compatibility with the ST 2110 suite. Discussions are ongoing, but the SC-02-12-R is considering altering the AES-X242 draft to "harmonize" with ST 2110-41. A decision will be deferred until a first draft of ST 2110-41 is available for the SC-02-12-R group to review.

Whether or not AES-X242 changes direction the SC-02-12-R hopes to have a final draft of AES-X242 completed in 2020.

AES-X243 Using AES70 connection management for AES67
SC-02-12L met before this meeting and only a few comments still need resolving. As the goal has been changed to produce a standard draft some editing is likely required to assure the language follows the normative style.

The group is confident a draft can be provided before the end of 2019.

AES70-1-R Review of AES70-1-2018: AES standard for audio applications of networks - Open Control Architecture - Part 1: Framework
This project is not on the active agenda as the review target is 2024.

AES70-2-R Review of AES70-2-2018: AES standard for audio applications of networks - Open Control Architecture - Part 2: Class structure
It was reported that a minor change is needed in relation to the unit of time. This is a change to the UML. This change will be done within this project. The status will be changed to "Revision being made" and goal date to 2020.

An issue was raised in regards to future changes to the UML file. The UML is referenced from the standard document as a link. To support multiple revisions of the UML the link should be changed to link to a landing page which would then list the revisions.

AES70-3-R Review of AES70-3-2018: AES standard for audio applications of networks - Open Control Architecture - Part 3: Protocol for TCP/IP networks
It was reported that an effort to add JSON to OCP is underway. As this is more than simple maintenance a new project will be requested for this work.


Liaison with MPEG
John Grant reporting: Not aware, haven’t been to MPEG lately, haven’t heard of anything earth shattering.

Liaison with IEC62379-1 (Common control interface, orig. BBC project in 2004, ATM etc.)
John Grant reporting: Getting to the frozen state. Information can still be found on the Nine Tiles web site.

Liaison with mobile
John Grant reported on 5G. Lot of focus on reducing header sizes to preserve bandwidth.

ST 2059 (Use of PTP for professional media sync.)
Paul Treleaven reported: The two parts are either in ballot or about to.

The impact to AES is that the standard is no longer going to support the clock classes that are in AES67 and various DARS related classes.

Liaison with Avnu ProAV AVTP
Morten Lave reported: Work is being done on improving the Milan specifications, implementations are getting to market and manufactures are going through certification.

There are interest among manufactures for an AES70 adaptation of CM3 for AVDECC connection management. The approach would be that an API is specified within Avnu. Any connection management control scheme would then hook into this API including a CM3 adaptation.

Liaison with NMOS/AMWA
Jeff Berryman reported: Roles of the different organizations are not clear. Goal is still to develop spec in TA’s and pass on to AES and SMPTE for standardization. The OCA is starting talks on NMOS convergence, create object models to reflect NMOS API’s. In the specific case of connection management the OCA models will be used.

Seems not to be as difficult as first assumed. Technical work can proceed at pace. Goal to have a preview of spec. at NAB 2020. After that specification drafts will be passed to SMPTE/AES, not clear at this point how this is to be done.

Next Meeting
The next meeting will be scheduled in conjunction with the AES 148th Convention, to be held May 2020 in Vienna, Austria.

AES - Audio Engineering Society