Preservation of both analogue and digital material, covers all actions necessary for providing permanent access to audiovisual materials. This is an efficient and safe environment for long-term storage with a guarantee of maximum integrity and authenticity. In the digital domain, preservation also includes the continued existence of the conserving organization itself, making the composition of business models, the arrangement of legal aspects, documentation and the processing of the materials also part of ‘preservation’.
Conservation refers more specifically to the implementation of maintenance, management and storage procedures. Material decays, even if it’s stored in a perfectly balanced way for the long term. Many parts of audiovisual collections have fallen into decline in some way or another over the years. With material that degenerates slowly, irreparable damage will eventually occur. It is then no longer possible to restore. Conservation of the collection slows down and even prevents this process. The decision as to which collections or individual productions should be conserved with priority, depends on the cultural-historical value, the re-use value and the technical condition of the analogue carrier.
Through passive conservation, collections are protected in a way that limits the risk of damage due to mechanical and/or climatic influences to a minimum. This applies to the storage of audiovisual documents in depots, during digitization and other modification processes, when exhibiting materials and during transport of materials. Solid storage systems and means of transport are of great importance in the protection process. Thanks to new (digital) forms of presentation, the original material can remain protected.
Active conservation is aimed at making a collection fully available for use and re-use. This can be achieved through renovation, restoration and/or digitization of the materials. All factors that disturb the ‘experience’ of the material (such as dirt, discoloration, damage to the image and/or sound) are removed or reduced as much as possible. Improper restorations from the past are corrected. Digitization of analogue materials is also an opportunity to consolidate the audiovisual documents in such a way that a good condition is guaranteed for the future. These active interventions are subject to the requirement of reversibility, full documentation and the current conservation techniques.
The source format (in which the material is recorded) is decisive for the rest of the preservation chain. A sustainable format is therefore a format that is as archival-worthy as possible and with that more sustainable than the intended use. It is advisable to create and/or store a source file of high quality for the archive. If desired, a lower resolution file can then be made available as a user’s copy. From a high-quality source material, it’s easy to convert to a format that can serve a specific purpose. Converting a low-resolution file compressed from the source to a high resolution (uncompressed) file has little use as the artifacts of the compressed source file persist.
Audiovisual collections consist more and more of digital formats. This concerns digitized material, born-digital material and digital multimedia forms such as internet video, video art, interactive productions, games and virtual reality. Digital carriers have their own requirements when it comes to conservation and sustainability. Sound & Vision ensures the quality of its digital archive by adhering to international standards such as the Open Archival Information System. By obtaining the standardized Trusted Digital Repository (TDR) certificate, the archive shows its stability and reliability to partners and stakeholders. An important part of a TDR is to follow technological developments and trends and to anticipate on the impact of these developments on the influx, storage and delivery processes, and desired preservation formats. The emergence of new formats such as transmedial, crossmedial and interactive productions, requires storage solutions and ways to keep these formats accessible.
In the project 'De Digitale Stad Herleeft' a number of recommendations have been made to preserve digital-born heritage. Read the manifesto 'FREEZE! A manifesto for the protection and preservation of born-digital heritage' and other publications from the project.
Managing digital content
In the dynamic digital domain, specific knowledge must be developed to adequately monitor and control the files, the associated metadata and their life cycle from the moment of production, via publication to archiving and renewed publication. In other words, the content must be managed.
In an integrated digital archive and production environment, the audiovisual archive is no longer the natural endpoint of a process. There are no more discrete archive products in the form of finished films or videos or audio forming a carefully selected reflection of the organization’s heritage and, at the same time, serving as a source of well-documented re-use. Digital files can be manipulated, are modular in structure and variable: endless versions are possible, and they all remain. There is an increasing divergence: the same content can be published on different platforms.
This situation makes it difficult to ensure the authenticity and integrity of materials and to secure them - as heritage - for the long term. Specific knowledge must be developed to adequately monitor and control the files, the associated metadata and their life cycle from the moment of production, via publication to archiving and renewed publication; the assets must be managed. Access control, version management and digital rights management are the most important issues here.
A digital format must be able to contain image and sound information for a longer period of time. Whether this information can be permanently reproduced depends not only on the sustainability of the format, but also on the available technology. Future hardware and software must be able to read the information. This technology is aging much faster than the digital formats. Encoding machines, file management systems, operating systems and networks are all subject to aging. In that sense, the lifespan of the formats is less important.
Archives have the task to keep and make available what they have selected and will select in the future. Continuous availability implies recurring verification and migration cycles. By choosing stable formats and sustainable technology, the frequency of migration layers can be limited. An alternative to migration is emulation. An emulator is a technical platform on which documents can be read in their original format. Sustainability is in fact a matter of keeping technology ‘current’. This applies both to forms of storage and to the various formats. There is no solution yet which guarantees digital sustainability (or sustainable accessibility, as it is often called nowadays). Worldwide, people work on this matter in projects, research programs and organizations.