October 2002 meeting of SC-06-04

[page updated 2003-01-27]

Report of the SC-06-04 Working Group on Internet Audio Delivery Systems of the SC-06 Subcommittee on Network and File Transfer of Audio meeting, held in conjunction with the AES 113th Convention in Los Angeles, CA, US, 2002-10-04

The meeting was convened by chair K. Brandenburg.

The Agenda was approved without amendment. The report of the previous meeting was unavailable prior to this meeting, therefore the report was read during the meeting and approved without amendment.

Open projects

AES-X74 Recommended Practice for Internet Audio Quality Descriptions
A draft of AES-X74 Recommended Practice for Internet Audio Quality Descriptions was circulated. At the last meeting SC-06-04 continued editing the draft document. A current version of this document, was sent by T Sporer to the document site for comment. No comment on this draft was received, however it was discussed during this meeting.

Sporer described proposals to put test material for MUSHRA listening tests onto the document site in order to provide standard test materials independent of the codec. Because there are both critical and un-critical materials to encode, a pre-selected set of listening materials would be necessary to avoid an arbitrary choice of materials leading to test results which could not be usefully compared with other tests using the same protocol.

It was felt that the test suite should comprise, say, 10 items, each about 20 s long. There had been some discussions in Munich about CD copyright issues. The first possibility is to re-use material from the CD, "Perceptual Audio Coders: What to Listen for" of the AES Technical Council. Sporer mentioned that the EBU have transferred copyrights to ITU for use in measurement tests, therefore the second set up an editing group to make a proposal for items for the next meeting.

After many discussions about this issue it was decided that A Mason will contact the EBU to request access a list of critical copyright material. Some modifications were made to clause 7 and to the annex in the draft document. These are already in the current draft document and will be further edited by the secretariat.

Mason discussed some recent reports from EBU concerning PEAQ measurements and a correlation to the data base of the first EBU internet audio coding tests. EBU would like to make available test material used in a subjective test done in September. The test material as well as the test report have already been posted to the new document site.

M. Keyhl reported on early results using MUSHRA. There were some problems in predicting a MUSHRA score using PEAQ results because MUSHRA scores tend to depend on test conditions. If there is additional information about the test conditions, it becomes possible to map the PEAQ results to the MUSHRA results reasonably well. As soon as Keyhl has more test results, he will inform the group.

AES-X98 Liaison with the Secure Digital Music Initiative (SDMI)
Brandenburg reported that the September 2001 SDMI meeting was cancelled due to lack of input. Subsequently there has been no activity. T. White of SDMI has communicated that he has been asked to keep the infrastructure intact in case SDMI would become active again. Accordingly, it is not proposed to retire AES-X98 at this time.

AES-X79 Distribution of Music over Non-Physical Networks
There are no activities to report. It seems there is no active interest from manufacturing partners regarding storage of metadata and authentication of mp3-files. Also, it seems impractical for this working group to do the work without such input. The meeting felt that major manufacturing companies involved in these activities should be invited to take part in the next SC-06-04 meeting. If there is still no interest, this project should be considered from retirement.

New projects

No new projects were raised or requested

New business

There was no new business

The next meeting will be held in conjunction with the AES114th Convention in Amsterdam, Netherlands.

AES - Audio Engineering Society