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Metadata Watch Report #2

[ contents | section 1 | section 2 ]

Section 3 - Domain reports

3.1 Audio-visual sector
3.2 Educational sector
3.3 Academic sector
3.4 Geographical information sector
3.5 Publishing sector

3.1 Audio-visual sector

1. REVIEW AND UPDATE OF ACTIVITIES

Three main initiatives have been identified.

• The AAF: Advanced Authoring Format

It is a joint initiative of a number of large media organisations and software companies. It aims at a new media industry standard file format, designed to meet information interchange needs. The media industry uses a wide range of source materials, as well as a set of highly varied capture tools with very different constraints (camera, keyboards, audio input sources, scanners). This wide variety leads to a great deal of time and effort spent converting media into formats, that can be used by the wide variety of authoring applications. AAF is a software implementation of SMPTE metadata and SMPTE labels, designed particularly to make it easy to work with large collections of interrelated sets of metadata and essence. AAF defines a base set of the built in SMPTE classes. These classes can be used to interchange a broad range of data between applications, but applications may have additional forms of data that cannot be described by the built-in classes. AAF provides a mechanism to define new classes that allow these applications. Besides the ability to format and manipulate metadata itself, the AAF software toolkit provides added capabilities for management of metadata sets, for user extensions and for pluggable modules. Authoring is being described as the process of creating multimedia content, including the related metadata. The AAF is specifically meant to function within this part of the production process and does not support the delivery phase of multimedia content (e.g. play-out, broadcast).

Expert opinion:

It is an important initiative with high industrial support. Picks up in a very constructive way on the work of the SMPTE Metadata dictionary. Currently standardising committees like the EBU-project group P/Meta are studying ways to relate to AAF.

• The ISAN: International Standard Audiovisual Number ISO 46/sc 9 N252.

The ISAN will distinguish one audio-visual work from the other. It is a unique number that is permanently assigned to an audio-visual work, it will identify that work across national boundaries and language barriers. It can be used in computerised applications, particularly those, which involve databases or the exchange of information about audio-visual works. Possible application domains: collecting societies to assist in the allocation of royalties; track the use of audio-visual works; anti-piracy purposes. For audio-visual works in digital form the ISAN will be embedded into the appropriate master copies of the work and transferred to subsequent copies made from that master. For analogue formats (film) ISAN should be affixed to the master negative. ISAN is a voluntary identification number without legal implication or meaning. The number will be assigned by an International ISAN Agency, appointed by ISO. The entity or person to whom an ISAN is given should have the capacity to permanently attach or link that ISAN to the specific audio-visual work that it identifies.

It is an ISO standard. Mute number. It can only be attached to complete productions, but does not support granularity. Should have added value to other standards and proprietary identifiers in the digital environment. MPEG2 and MPEG4 standards for the coded representation of multimedia and audio-visual objects already provide a space for the ISAN identifier in the MPEG format. The SMPTE Metadata dictionary has defined ISAN as a metadata entry under the class Identifiers and Locators. The EBU Projectgroup P/meta is currently looking into the viability of ISAN as a broadcast identifier.

• The UMID: Unique Material Identifier (UMID)

A Unique material Identifier provides a reference for all captured audio-visual content units in a clip or shot, so that particular a content unit can always be located either locally, remotely or on a archive storage medium. The UMIDS provides for the link between the essence (video, audio, graphics, stills etc.) and the metadata and generates a time code and date (time-axis) for synchronising this data. UMIDs can also be used to track copyright information about the essence. UMIDs are automatically generated by the systems and support granularity up to the level of shots and video and audio frames. The UMID structure contains a set of components that each represents a key-aspect of the audio- or video essence. There are two sorts of UMIDs: the basic UMID, with the minimal components necessary for the unique identification (the essential metadata) and the extended UMID that provides information on the creation time and date, recording location and the name of the organisation and the maker (the signature metadata). Together these basic and extended UMID have a defined length of 64 bytes.

Standard status. Intelligent number that in itself includes some of the most important metadata about a content clip. Important identification standard for the audio-visual production environment. Supports granularity (important in the process of creation and authoring). Provides a link between metadata and essence. High industrial support by some of the most important manufacturers of audio-visual equipment and media-management systems. Already included in most of the (forthcoming) metadata standards for the audio-visual production environment.

>>Section 3.2 Educational sector

[ contents | section 1 | section 2 ]

Maintained by: UK Office for Library and Information Networking (UKOLN)
Last updated: 07 August 2001