D24 - Metadata Watch Report #3

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Metadata Watch Report #3

Section 5 - Domain reports

5.1 Industry sector
5.2 Publishing sector
5.3 Audio-visual sector
5.4 Cultural Heritage sector
5.5 Educational sector
5.6 Academic sector
5.7 Geographical information sector

5.3 Audio-visual sector

Correspondent: Annemieke de Jong, Nederlands Audiovisueel Archief

5.3.1 Current state of the domain

Compared to the networked 'bibliographical' domain, the development of metadata dictionaries and metadata schemes for audiovisual media is a relatively young area. Allthough certain specialized standards for parts of the audiovisual production process have already been developed and in some cases are indeed operational, not many of them have been given formal status. No detailed, official standards for interoperable 'audiovisual' metadata (that includes and integrates all digital production, distribution and archiving processes) yet exist and there are no commonly accepted models for the audiovisual production environment as a whole.

In order to define a metadata scheme for a media management system for the production environment two interrelated aspects have to be considered . In the first place the system has to be geared to the specific requirements of the audiovisual organisation it is used for; in the second place the necessary protocols and standards should be moulded as closely as possible to international schemes and standards as to enhance interoperability and facilitate exchange of audiovisual documents on a national and on an international scale. Metadata schemes that are developed locally have therefore to be synchronized with internationally accepted standards. Whenever possible local definitions should be translated to international standards from the start on. For the production and distribution of digital television and radio material the SMPTE Metadata Dictionary and Engineering Guidelines function as an important reference. The same goes for the activities of the MPEG-7 group, that -allthough still in an early stage of development- are being closely monitored for developing schemes for multimedia content in the professional environment. For the category 'descriptive metadata' Dublin Core usually functions as an important reference. The Standard Media Exchange Framework of the BBC (SMEF) is sometimes used as a reference data model for broadcasting production environments and media managment systems.

Within the audiovisual production, distribution and archiving domain interoperable schemes are developed on various levels:

1. Projectbased metadata schemes.

Local projects or initiatives for digital production, e.g. within one public or commercial broadcasting company
Projects with a broad, national scope e.g. The Digital Platform of the public broadcasters in the Netherlands, that prepairs a common digital infrastructure covering a metadata dictionary and a datamodel. Another example is the Digitaal Erfgoed Nederland (DEN) initiative, that aims at establishing a web based interoperable interface that gives access to digital collections of various nature, including the audiovisual national heritage.
European projects within the Fifth Framework, that are aimed at establishing digital video libraries e.g. the European Chronicles Online (ECHO).

2. 'Industrial' metadata schemes.

Industrial players sometimes develop their own schemes and models, usually including (parts of) existing standards or standards-in-development and adding metadata and datamodel requirements coming from their customers. For media management systems these models are usually SMPTE compliant.

3. Interoperable schemes coming from the standardizing community.

e.g. P/Meta, one of the projectgroups of the European Broadcasting Union (EBU) aims at harmonizing the SMPTE Metadata Dictionary, Dublin Core and MPEG-7 with the requirements for exchange of audiovisual information between European broadcasters, archives and consumers.

5.3.2 Main issues

Generally speaking one of the main issues is the difficulty to synchronize the work that is being done within standardizing committees, projects, pilots and other initiatives on the level of tempo, goals en scope. Currently there is no centralized, systematic and well-timed exchange of information on the various local, international and national projects that concern the development of 'audiovisual' metadata schemes. Standardizing commitees work slow and thorougly and broadcasters and producers on the other hand - due to the rapid technological developments - are forced to act and cannot wait for yet another new version of the standard. Another problem is the still rather inadequate communication between the various contributing communities to schemes, both on an internal, company level and internationally. Communication problems may be caused by the differing professional (technical, archival, production) backgrounds of the contributors that need to integrate requirements to come to an interoperable scheme. The variation in the many audiovisual production models also leads to problems in establishing common metadata models, which makes it difficult to standardize on a detailed level the various groups and classes of metadata that are required for digital media systems.

Issues more specific:

Harmonizing the user requirements within the various audiovisual production domains
Determination of the universe of discours: to what level should information be exchanged?
Standardizing audiovisual production, distribution and archiving process models and working procedures
Standardization of data structures and data models, entities and attributes
Standardizing type fields and field values
The development of globally accepted, registered unique identifiers for audiovisual essence to link the stored audiovisual material with the related documentation through the audioviosual production process.
Multilingual aspects in interoperable schemes
Understanding and integrating of the various categories and types of metadata in the audiovisual environment including media processing metadata, technical metadata, production related metadata, descriptive categories
The issue of integrating the legacy archives and legacy catalogues into the digital domain.

5.3.3 Trends, overlaps and gaps

Generally speaking the same kind of efforts are being undertaken in many 'similar' audiovisual environments concerning the development of metadata schemes. However, as for the more specific levels of the schemes and models this can hardly be avoided. Each audiovisual production environment has its own specific procedures and requirements and these need to be reflected in the company process schemes and data models. Besides this, the environments may differ in the extent to which exchange of information is restricted in view of copyrights and commercial exploitation. In other cases (parts) of internal schemes hold detailed information on internal business procedures and working processes and can therefore not be freely shared with other environments. It is for this reason that initiatives like that of EBU's P/Meta, that work on connecting the requirements, schemes and models of various broadcast environments to international standards, are of vital importance. Still, in order to enhance interoperability from the start on, it would be very usefull if more professional platforms are established where broadcasters and other av-producers may acquire detailed, objective information on which work is already done and what schemes are available for reference.

Presently many pilot projects are running within the broadcast environment that include the development and use of metadata schemes for production, distribution and archiving or for any of these three processes. Forced by the rapid increase of digital production of audiovisual materials and the lack of usable common schemes and standards, many broadcasting companies and other producers are currently developing their 'own' metadata schemes for these pilots and projects. During this process they usually start with formulating local user requirements and defining local process models and dataflows. After this they might see to which extent their proprietary models can be harmonized and mapped with existing standards or standards-in-progress for (parts of) the audiovisual domain, if any. New, commercial broadcasters that hold no legacy archives or catalogues currently tend to be in front of the developments with often a full working digital environment, using proprietary models and metadata dictionaries

The awareness amongst broadcasters, av-producers and others players in the audiovisual field that interoperability with other environments is an essential requirement, fortunately is growing rapidly. More and more it is realised that failure to adopt international standards in an early stage effectively means that local systems are inefficent and become more inefficient. Subsequent adaptation of local systems is extremely labour intensive and the gradual implementation of standards tends to be guided by technology rather than by user requirements. In this scenario the number of unique identifiers would slowly grow and the chances of interoperability would diminish. Broadcasting companies for instance, could be manouvered into a very unfavourable position compaired to audiovisual organisations that are more experienced in e-commerce. But allthough it is recognized that much can and needs to be integrated into international standards, there will allways remain elements of purely local importance which then may be taken on as extensions.

The contribution to the development of interoperable schemes for various areas at different stages of growth still stem from the respective professional qualifications and commercial interests of the participants. Allthough communication is still not sufficient, it can be observed that, especially during the last 12 months, the various developments are increasingly coordinated at European and international levels, whilst at the same time organisations that produce audiovisual materials have their own internal services and production services work much closer together than before in jointly establishing projects and pilots for the digital production environment. Broadcast engineering, information technology and the world of documentation and archiving are joining forces more and more to the benefit of quality levels all over.

In Appendix A, a number of application profiles for the audio-visual sector are described.

>>Section 5.4 Cultural Heritage sector

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