Report of the meeting of the SC-02-02 working group on digital audio interfaces, of the subcommittee on digital audio, held in Los Angeles, California, US., 2014-10-09
The meeting was convenened by chair J. Grant.
The agenda, and the report of the previous meeting, held in New York, 2013-10-17, were approved as written.
Projects assigned to this group but not mentioned here had no action requested or required - see www.aes.org/standards/meetings/project-status.cfm for details.
Open Projects
AES3-x-R: (x = 1 to 3) Review of AES3-x-2009, AES standard for digital audio - Digital input-output interfacing - Serial transmission format for two-channel linearly represented digital audio data (first three of four parts)
There having been no objection on the reflector, and there being none at the meeting, these documents should be reaffirmed.
AES3-4-R: Review of AES3-4-2009, AES standard for digital audio - Digital input-output interfacing - Serial transmission format for two-channel linearly represented digital audio data - Part 4: Physical and electrical
J. Paul presented his recently-uploaded document AES3-4-AES2idRECjp.doc, which reports the current status of the project to update AES3-4 and AES-2id. The intention with regard to RS422 is to warn that many of the currently-available RS422 integrated circuits will not work at higher sample rates, and to adjust parameters so that faster ICs which do not conform to RS422/V.11 can also be used. The meeting agreed with the proposal to identify and mark cables to show the maximum signalling rate they would support. Results of testing with a variety of cables are being documented in a paper which, it is expected, will be made available to SC-02-02 in a few weeks' time.
P. Treleaven noted that SC-05-02 and SC-05-05 have recently being working on EMC issues (including for AES48 and AES54), and there should be liaison with them regarding EMC.
As there is more work to be done before the revised text is ready, AES3-4 should be reaffirmed now, with the intention to revise it next year.
AES-2id-R: Review of AES-2id-2006 (r2012): AES information document for digital audio engineering - Guidelines for the use of the AES3 interface
The intention is to revise AES-2id at the same time as AES3-4; it would not need to be reaffirmed until 2017.
AES5-R Review of AES5-2008: AES recommended practice for professional digital audio - Preferred sampling frequencies for applications employing pulse-code modulation
AES5 has been reaffirmed with a date of 2013 and the new printing has now been published.
AES10-R: Review of AES10-2008: AES Recommended Practice for Digital Audio Engineering - Serial Multichannel Audio Digital Interface (MADI)
AES10 has been reaffirmed with a date of 2014 and the new printing has now been published. Task group SC-02-02-L to handle revision of AES10 and AES-10id as well as AES-X213.
AES11-R Review of AES11-2009: AES Recommended Practice for Digital Audio Engineering - Synchronization of digital audio equipment in studio operations
AES11 needs to be reaffirmed now, with the intention to revise it next year.
AES-R8: AES standards project report - Synchronisation of digital audio over wide areas
Revised text has not yet reached consensus.
Development Projects:
AES-X182: AES/Ethernet Simple Open Protocol
Secretariat formatting is awaited, and is expected before the end of the year.
AES-X196: Use of AES3 with high sampling rates to carry multi-channel audio
Secretariat action to format the two schemes as an Information Document is still outstanding, and will not be given a high priority. There has been no further input from the organisation that originally requested this project regarding which of the proposals would work best in their system.
AES-X213: MADI over twisted-pair cabling
Final TG draft is still awaited.
Liaisons:
J Yoshio reported that there are two proposals for IEC TC100 TA4's amendment of IEC 60958 Parts 1 and 3 to support carriage of 22.2 format (24 channels), one being similar to the X196 proposals and the other a new format. Support for new MPEG-H standards will be added to IEC 61937 Parts 4 and 7. IEC TC100 will meet in Tokyo in the first week of November.
The next meeting will be scheduled in conjunction with the AES 138th Convention in Warsaw, Poland, 2015-05.
