SC-02-08 meeting, Milan, Italy, 2018-05

Report of the meeting of the SC-02-08 Working Group on audio file transfer and exchange of the SC-02 Subcommittee on Digital Audio, held in Milan, Italy, 2018-05-24

The meeting was convened remotely by Mark Yonge.

The formal notice on patent policy was read.

The agenda and the report of the previous meeting, held in New York, 2017-10-20, were approved as written.

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

Development Projects

AES-X236 - IEC 62942 liaison, IEC 62942 liaison, Broadcast Wave Format file
Scope: Adoption of AES31-2 as an IEC standard for broadcast wave format file, with addition of optional UBXT chunk to carry international character sets.
Status: The committee draft (CD) for IEC 62942 was discussed in New York and comments offered to improve the text. These comments are being considered in the IEC project team.

Japanese experts responded 2017-12-11 to the AES comments proposing alternative language. Some of these proposals seemed controversial so the chair replied 2018-01-12 in order to clarify details. The comments were posted to this working group as "x236-180112-iec-62942-cd-comments.pdf", and the reply email was copied to the group reflector at that time, and is now posted to the document site as, "x236-180112-IEC 62942 comment observation.pdf".

The meeting supported the replies as written, with the following observations:

a. In annex K.3, we had proposed adding the text, "When data is entered into the human-readable fields of the 'ubxt' chunk, the equivalent fields in the 'bext' chunk should provide an ASCII equivalent if possible, or a null character." We now propose adding a note to clarify that this ASCII equivalent is intended to be default text chosen by the application and that translation by the operator is not expected. An example might be, "See data in UBXT chunk".

b. We had proposed the following additional text in clause 4.4 above Table 1: "All the items except Description, Originator, OriginatorReference and CodingHistory should have the same content as that of each corresponding item of the ubxt chunk (see annex K), if present. If machine-readable data in the 'bext' chunk is updated, the corresponding machine-readable data in the 'ubxt' chunk should also be updated identically." In discussion it was understood that the recommendation ("should") could not be a requirement ("shall") because existing applications in the field over the past 20 years may not be able to recognize the international 'ubxt' chunk and so will not be able to comply. It is expected that newer applications will replace these legacy applications in time.

The chair will continue to liaise with IEC as that text develops to a conclusion.

Open Projects

AES31-2-R Review of AES31-2-2012 Audio-file transfer and exchange - Part 2: File Format for Transferring Digital Audio Data Between Systems of Different Type and Manufacture
Scope: This standard defines a file format for interchanging audio data between compliant equipment. It is primarily intended for audio applications in professional recording, production, post production, and archiving.

Status: A review is now overdue. The chair has proposed a revision to AES31-2 to include the option for a 'ubxt' chunk as intended for IEC 62942.

As soon as possible, a new draft revision of AES31-2 will be prepared taking into account the discussions so far in AES-X236.

AES69-R Review of AES69-2015: AES standard for file exchange - Spatial acoustic data file format
Scope: This document standardizes a file format to exchange space-related acoustic data in various forms. The format is designed to be scalable to match the available rendering process. The format is designed to be sufficiently flexible to include source materials from different databases.

Status: Proposal for revision expected.

No action was requested or required.


No new liaison information

New projects

No new projects were proposed.

New business

No new business was proposed.

The next meeting will be scheduled in conjunction with the AES 145th Convention, to be held 17 to 20 October 2018 in New York, NY, US.

AES - Audio Engineering Society