AES Standards News Blog

The  Call for Comment on DRAFT AES62-xxxx, AES standard for audio connectors - Modified XLR-3 Connector for Digital Audio has been published, 2011-06-17.

The  Call for Comment on DRAFT REVISED AES50-xxxx, AES standard for digital audio engineering - High-resolution multi-channel audio interconnection (HRMAI) has been published, 2011-05-23.

http://www.aes.org/standards/comments/

 AES-21id-2011 AES Information Document for audio-file transfer and exchange - Screen-less navigation for high-resolution audio on Blu-ray Disc has been published.

http://www.aes.org/publications/standards/

High-resolution audio, presented as uncompressed LPCM, has been waiting for a suitable transport format for some time. The Blu-ray Disc (BD) format offers such a transport and supports the necessary linear and lossless codecs as part of its basic specification. While many BD players can be found in home theatre and games environments, there are some issues that need to be addressed before they can be introduced into a hi-fi environment that does not have a screen to present visual menus for audio stream setup and track selection. This recommended method specifies a structure for authoring a BD ROM to enable playback in screen-less consumer systems, and to provide simple track selection from the remote control.   

From the time of its general introduction in 1983, Compact Discs and CD players have become a familiar part of consumer hi-fi systems. The method of operation has been consistent during that period: put a disc in the tray; accept track 1 by default or select another; press Play. No other setup was expected or available.

The DVD was introduced in the late 1990s primarily to carry movies as a replacement for consumer videotape formats. All user interaction was intended to be directed by a remote control, with visual feedback from the screen that was automatically available in a home-video system. High-resolution audio was not a primary factor in the initial design of DVD, in part because the data capacity of a DVD, although considered large at the time, was insufficient to carry multi-channel uncompressed LPCM (for example).

The introduction of the Blu-ray disc (BD) format in 2006 offered sufficient data capacity for high-resolution audio to be considered practically and without compromise. More importantly, the basic specification of the BD included a wider range of lossless audio coding options, including up to 8 channels of high-resolution LPCM.

Like their DVD precursors, BD players are designed to be used in conjunction with a video screen, and so screen-based visual feedback was again assumed for operational control. While this will be satisfactory for some users, many audio users will still prefer the simplicity of CD operations. Additionally, in many consumer hi-fi systems, there will be no existing screen and the extra cost of providing a screen just to see the menu could make the high-resolution audio proposition impractical.

It is possible, without making any changes to the BD player, to provide the necessary functionality for screen less playback of high-resolution audio. The necessary functionality can be provided using programming that is included at the authoring stage of the disc.

The screen-less modes described here are a function of programming during the disc mastering stage. They use the standard BD capabilities and do not seek to limit them in any way.

This document was proposed as a Call for Comment under the document number AES-17id.  During the comment process it was pointed out that this document could be confused with existing documents such as AES17 on digital audio measurement.  Accordingly, without changing the content, the document has been re-designated AES-21id to avoid any such confusion.

AES-10id-2005 (r2011) Engineering guidelines for the multichannel audio digital interface AES10 (MADI) has been reaffirmed in a new printing.

The AES10 standard defining the multichannel audio digital interface (MADI) provides for the serial digital transmission of 32, 56, or 64 channels of linearly represented digital audio data at a common sampling frequency within the range 32 kHz to 96 kHz, having a resolution of up to 24 bits per channel. The format makes possible the transmission and reception of the complete 28-bit channel word (excluding preamble) as specified in AES3, providing for the validity, user, channel status, and parity information allowable under that standard. The transmission format is of the asynchronous simplex type and is specified for a single 75-ohm coaxial cable point-to-point interconnection or the use of fibre-optic cables.

This companion Information Document deals with a number of implementation details not laid down in the AES10 standard, or unnecessarily restricted by the standard, concerning synchronisation, packing, and so on which have given rise to delivery problems.

The latest revision of AES-10id is divided into sections dealing with: input from AES3 bitstreams, output to AES3 bitstreams and including additional concerns for other digital audio interfaces, synchronisation of AES3 to MADI decoders, synchronisation of MADI to AES3 decoders, and some general problems uncovered by experience.

http://www.aes.org/publications/standards/

 The  Call for Comment on DRAFT AES57-xxxx, AES standard for audio metadata - Audio object structures for preservation and restoration  has been published, 2011-03-18.

http://www.aes.org/standards/comments/

The  Call for Comment on DRAFT AES60-xxxx, AES standard for audio metadata - Core audio metadata  has been published, 2011-03-18.

http://www.aes.org/standards/comments/

AES42-2010 AES standard for acoustics —Digital interface for microphones has been published.  This standard revises and updates AES42-2006.

The main addition to this standard is the AES42 system-command set to enable storage and recall of user settings in the microphone itself.

Additionally a new feature has been introduced: Since the upload times were not acceptable for a firmware update using the AES42 interface the bit rate can now be increased. This higher bit rate, called Fast-DPP mode, can be used to transmit DPP commands or firmware update data. It is introduced as an option.

Furthermore an optional periodic transmission control feature is introduced to allow manufacturer specific command sets for remote control of microphone features.

http://www.aes.org/publications/standards/

Call for Comment on DRAFT AES-17id-xxxx, AES Information Document for audio-file transfer and exchange - Screen-less navigation for high-resolution audio on Blu-ray Disc™ has been published, 2011-01-12.

http://www.aes.org/standards/comments/

A Call for Comment on REAFFIRMATION of AES-10id-2005, AES information document for digital audio engineering - Engineering guidelines for the multichannel audio digital interface, AES10 (MADI) has been published 2011-01-04.

http://www.aes.org/standards/comments/cfc-reaffirm-aes-10id-2005-110104.cfm

A new AES Standards project, AES-X192, "High-performance streaming audio-over-IP interoperability" has been initiated.

The project aims to "specify protocols and interoperability guidelines for professional, low-latency streaming audio over high-performance IP networks", with the intent to produce a standard.

The most recent generation of networked audio technology uses a diversity of proprietary and standard protocols. Despite a common basis in IP, none of the systems deployed or under development are interoperable. The latest crop of networking technology has not yet reached a level of maturity precluding changes to improve interoperability.

A standardized basis for interoperability will help designers of equipment that inter-operates with other equipment, and will support extended multi-vendor systems with greater predictability.

http://www.aes.org/standards/meetings/init-projects/aes-x192-init.cfm