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

Report of the meeting of SC-02-02 Working Group on digital input/output interfacing of the SC-02 Subcommittee on Digital Audio, held in Munich, Germany 2009-05-07

The meeting was convened by chair J. Grant.

The agenda and the minutes of the previous meeting were approved.

Open projects

AES3-R, Review of AES3-2003: AES standard for digital audio engineering - Serial transmission format for two channel linearly represented digital audio data
Amendments 5 and 6 have been published. No further amendments to the single-part text are planned before it is replaced by the output of project AES3-X.

AES3-X, Restructure of AES3-2003: AES standard for digital audio engineering - Serial transmission format for two channel linearly represented digital audio data
No changes were proposed to the drafts of 17/19 April 2009. New drafts with Abstract, Foreword, and Introduction added will be circulated shortly. When the new AES3 is issued, a note will need to be added to the current version of AES-2id warning that references to AES3 are out of date, unless the revision of the references has been completed by then.

The meeting expressed its thanks to Robin Caine for his work on this project.

AES5-R, Review of AES5-2008: AES recommended practice for professional digital audio - Preferred sampling frequencies for applications employing pulse-code modulation
The 2008 revision has now been published. Current work in SMPTE may result in new sampling frequencies, in which case the group would need to consider whether to add a reference to them to AES5.

AES10-R, Review of AES10-2003: AES Recommended Practice for Digital Audio Engineering - Serial Multichannel Audio Digital Interface (MADI)
ITU-R working-party 6B is writing a standard which is the same as AES10-2008 except that the 64 to 96 kHz sampling frequency (option (c) in 5.1) is omitted. They are using parallel text because AESSC is not yet one of the bodies to whose documents they can make normative reference. The current ITU text has been uploaded to the SC-02-02 document area with filename R07-WP6B-090427-TD-0046!!MSW-E.doc and you are encouraged to compare it with AES10-2008 and report to this reflector whether there are any other changes.

AES11-R, Review of AES11-2003: AES Recommended Practice for Digital Audio Engineering - Synchronization of digital audio equipment in studio operations.
The revised text is currently the subject of a Call For Comment.

AES41-R, Review of AES41-2000 (r2005): AES standard for digital audio - Recoding data set for audio bit-rate reduction
A. Mason presented the draft which was uploaded to the SC-02-02 document area on 30th April. Please review this draft and send any comments to this reflector. If there are no unresolved comments by 29th May it will be deemed to have been accepted by the Working-group.

AES47-R, Review of AES47-2006: AES standard for digital audio - Digital input-output interfacing - Transmission of digital audio over asynchronous transfer mode (ATM) networks
Amendment 1 was published in February. This project can be transferred to the "passive" list, so should be in the annex to the agenda of the next meeting.

AES50-R, Review of AES50-2005, High Resolution Multichannel Audio Interconnection (HRMAI)
U Zanghieri reported that the current owners of the technology have now finalised their SDK, and there are about 5 changes to AES50 arising from that work. They expect to be able to provide input in time for the next scheduled review of AES50 in 2010.

AES-2id-R, Review of AES-2id-2006: AES information document for digital audio engineering - Guidelines for the use of the AES3 interface
The Secretariat will revise the text to change the references to AES3 to refer to the four-part version. It may be appropriate to do a more radical revision in time for the next scheduled review in 2011.

Development projects

AES-X139, Liaison with EBU P/AGA
The EBU P/AGA meeting originally scheduled for 8th May is now to be held on 11th May elsewhere in Munich. Agenda items include track allocation for file exchange, monitoring & metering, and A-V synchronisation including problems caused by the extra frame delay with Dolby-E. EBU are writing a "lip-sync cookbook".

AES-X161, Digital interface for loudspeakers
S Heinzmann reported that all the work for this project is now proceeding in IEC PT 62537, and project X-161 is therefore no longer required. If no objections have been sent to this reflector by 31st May, X-161 will be closed.

AES-X182, AES/Ethernet Simple Open Protocol
A draft standard is expected in July, which would allow the group to review it before the New York meeting. The system is already in use, with about 1000 nodes in the field in clusters of 10 to 100.


IEC 61937, Digital Audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958
J Yoshio reported on IEC PT 61937-10, -12, -1, and -2, 60958-3, and 62574, all of which will meet on Saturday 9th May. Details are in the SC-02-02 doecument area with filename "IEC_Liaison_Report_20090507.pdf". IEC TC100 has a new technical area, TA11, which initially has two projects, one for speaker (as distinct from channel) assignment and the other for control of loudness through the whole chain from source to speakers: a report on user tests has been written in Japanese; it is currently being translated and will then be submitted to SMPTE.

C Chambers reported that the EBU SMPTE task force on time and synchronisation has reached the point at which it would be useful for them to have comments from SC-02-02 members. The current draft is in the SC-02-02 document area with filename "Joint_EBU_SMPTE_Timing_and_sync_request_for_standardisation_V16.doc".

New Projects

There was no new business

New Business

There was no new business

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

This report will be considered to have been approved if no objections have been sent to this reflector by 7th June 2009.

AES - Audio Engineering Society