Meeting of SC-06-02, 2004-05

Report of the meeting of the SC-06-02 Working Group on Audio Applications Using the High Performance Serial Bus (IEEE 1394) of the SC-06 Subcommittee on Network and File Transfer of Audio meeting, held at the 116th AES Convention, Berlin, 2004-05-08.

The meeting was convened by Chair J. Strawn

The agenda and the report of the previous meeting were approved as written.

Open Projects

AES24-1-R: Review of AES24-1-1999: AES standard for sound system control - Application protocol for controlling and monitoring audio devices via digital data networks - Part 1: principles, formats, and basic procedures.
To be withdrawn.

AES24-2-R: Review of AES24-2 1999: AES standard for sound system control - Application protocol for controlling and monitoring audio systems - Part 2: Class tree.
To be withdrawn.

Development Projects

AES-X075: IEC Liaison for IEC-PAS 61883-6
Fujimori-san reported concerning the progress of IEC-PAS 61883-6 edition 2. Comments have come from various national bodies. Table A-1 in the current version has incorrect values for TRANSFER_DELAY. All other comments were editorial except from the German committee. After the SC-06-02 meeting there was a short meeting to review eight of the comments.

AES-X101: Data Type, Properties, and Method Definitions for Audio Device Application Program Interfaces (API)
The Secretariat is working on the next stage of the document.

AES-X127 : Liaison with IEEE 1394.1
S. Harris reported that the IEEE P1394.1 bridging standard is currently on its second recirculation ballot that will close on 2004-05-15. An official standard is expected to be available in the second half of this year. Harris was asked to work on a synchronization document proposal for the October meeting. We will then revitalize our mothballed Project X132, assigned to SC-06-02-G, to finalize that. Strawn undertook to submit an initiation form for X132 [done 2004-05-23].

AES-X137: Liaison with 1394 Trade Association (1394 TA)
Fujimori-san reported that the 1394 TA is discussing:

  • Plural-Node Implementation of a Professional A/M Devices
  • General Data
  • AV/C Music Subunit Ver. 1.1
  • AV/C Stream Information Ver. 1.1
  • AV Synchronization
Yoshio-san of Pioneer explained the latter, which was discussed again at the Audio Visual Working Group (AVWG) in Shanghai.

The idea is to standardize synchronization between audio and video signals going through 1394. If the video delay is different from audio delay, there can be a lip sync problem. Lip sync problems are now appearing in the market, and consumers are complaining: digital broadcast equipment, or DVDs with compressed audio, can feed a video interface and audio interface with separate delay amounts. Japan will propose a synchronization standard to IEC TC100. Yoshio-san will post slides concerning this to the SC-06-02 web site.

Concerning Plural-Node Implementation of a Professional A/M Device, the document is known as TB2004001, and is at the final draft stage. The TA welcomes comment from our members. Fujimori-san explained the ideas of Enabler Node and Transporter Node. Fujimori-san will upload a copy of this to the SC-06-02 document site for us to give comments. He will also upload his TA presentation from last year.

Concerning the AV/C Music Subunit and AV/C Stream Information Ver. 1.1, these were proposed by BridgeCo and Apple. The purpose is to extend the subunit. They offer the capability of grouping signals, for example to form a stereo pair. They also envision naming the functionality of plugs; for example, the user can put names on plugs. For Stream Information Ver. 1.1, the TA wants to extend so-called "compound data". Currently, the Streaming Information Command Set supports only unified data packets, for example a packet containing only linear audio data.

For General Data, we thought that the FDF definition would be allocated in the next version of A/M protocol, and the actual implementation document would be provided by AES. TA had thought that in the next A/M protocol, it would refer to the AES document. Fujimori-san has asked the TA board of directors to provide a TA document for AES to review. We didn't get an answer yet.

AES-X126 : Profile for professional audio over 1394
SC-06-02-G had met earlier in the same day. The group intends to put out a call for requirements, to be also published in the Journal.

The document on general data is in progress. M. Yonge will coordinate with the Trade Association and other bodies to resolve the chicken and egg question concerning assignment of an FDF to AES, mentioned above.

New Projects

No new projects were proposed.

New Business

B. Moses reported on proposals for 1394.c, Ethernet and Firewire to share an RJ45 connector and Cat 5 cable. The 1394.c committee believes that major technical questions have been decided. M. Teener has set a goal of finishing the standard by June. Moses will supply us with the URL for the draft standards.

The next meeting will be held in conjunction with the AES 117th Convention, in San Francisco, US., 2004-10.

AES - Audio Engineering Society