Conformación de las Mesas Receptoras

It seems we are left looking for a technology we don’t yet have. The DI archival preservation material is still a film image (much to the relief of those Scandinavian archives who have had the greatest number of DI productions to preserve as part of their compulsory legal deposit of cinema productions). But within months this could (in Scandinavia will) change and the cinema format, in some instances, will become a set of digital files. Film producers, rights holders and collections might, probably will, have to make a new decision. Is the ‘original’ the uncompressed files created in the post-production house from which all the various deliverables were made – or the compressed files despatched to the cinema for projection (and there could be several versions depending on the cinema and its pro- jection equipment).

The FIRST Project is still running, but already its conclusions are altering current attitudes to digital archiving. The project looks at moving film images which are, in general, larger than any video files and probably comparable with the anticipated digital cinema master files in the future, but increasingly its findings are resonating with all-digital moving image archiving.

These issues, listed by Eddy Goray of Radio Télévision Belge de la Communauté Française de Belgique, in the FIRST Report: State of the Art, 2003, are these:

• Longevity: Existing analogue films, properly stored, have a life that can be in the order of a century. Why should archivists not seek a similar longevity digital storage format? At this time, however, this is unlikely to be achieved. The best existing digital support on the market now does not have a life expectancy better than 30 years, in the very best storage conditions.

• Capacity: The most available technology on the market for storing digital is magnetic tape. This support uses the cheapest existing support technology and is able to provide the largest capacity (S-AIT format with 0.5 TeraByte (TB) in native format, and 1.3 TB using lossless compression (LLC). Unfortunately this capacity is far from able to store film or cinema images at full resolution (nominally 4K for the purposes of this explanation) using only LLC. The capacity needed could be more than 6 TB for a film of 90 minutes, requiring of five tapes of 1.3 TB each per film!

• Speed: The time to download or upload the digitized film to or from the digital library should not be prohibitive. Unfortunately that same 90 minute film S-AIT tape will, today, take 22 hours to upload or download one feature film!

• Vulnerability: Magnetic tape is sensitive to electromagnetic fields, and other supports too have short lives or very critical storage conditions for longer lives.

• Alternative technologies: At this time (this is the view of the FIRST team) the only other interesting and relevant storage is optical tape. Digital optical tape technology has existed since the 1980s but due to very high cost and restricted market interest there has been little commercial success. The technology has the possibility of high capacity storage in the range of 1 to 10 TB of data on one single tape unit. It is associated with high transfer rates (in the range of 0.8 to 1.5 Gb/s), although the writing process is much slower. Due to the flexible plastic used, long term storage times of more than 100 years are forecast.

• Low life expectancy due to obsolescence: A shorter life expectancy (even a 30 year maximum) of new digital supports creates a problem of greater impact; the consequence of rapid technological evolution changing both equipment and format more and more frequently. For the first computer generation, the life cycle was around 10 years. Now within 6 months practically each component of a computer changes, in both price and performance. The situation with software is the same, with the growing of the power of micro- processor. Software becomes more useful and more user-friendly but needs more power to run. Customers who want to use the most recent generation of software have to buy the most recent hardware.

Analysing the roadmap of the existing different digital tape formats on the market, we can see that practically every two years the characteristics will change (in both capacity and throughput). Theoretically we have seen in the past that with each new change in support characteristics a new drive dedicated to this new support was presented. We will be obliged to change both support and drive every four, six or eight years, whether we want to or not, due to the lack of support for old equipment. The cost of such opera- tions needs to be analysed (and often has not been considered). To add to our woes, the same can be said about the software that controls the drive. • Migration: A solution to obsolescence is so-called migration. The migration

process creates two main critical issues, the cost, and the duration of such a process, and both are related to the quantity of content stored in the old digital format. Careful calculation needs to be made in order to see if this kind of scenario is really manageable. We must avoid a situation where the time of migration from one format to another is bigger than the lifetime of a format, and typical cinema image files will be very large. Conceivably, migra- tion is a policy that large cinema collections cannot justify, economically

or practically, even if it is justifiable for smaller access images (and this is potentially questionable too).

Conclusion

No adequate solution exists for long term digital cinema film storage under the existing user’s requirements, and increasingly it seems that this must also be said of digital cinema. It probably also applies to any large collection of image files.

• Research and development is needed on an entirely new storage support. • Or the existing users’ requirements need to be analysed and discussed with

the intention to modify them in order to find a compromise that can be fulfilled by technology in the short term. If there is sufficient market potential any manufacturer will be interested (and the modern cinema film industry has similar unfulfilled requirements).

• A thorough investigation is required on the use of low levels of lossy com- pression to establish whether there is potential for this technology.

• Further investigation should be made of optical tape technology because this seems very well suited to the needs of large files in terms of longevity, capacity and speed. This technology seems at this time to have more benefits than other alternatives. Carefully analysed, developed, industrialized (if no drawbacks are found) and widely used (to achieve an economy of scale), this could be a possible future solution for long term digital storage.

So, Cinderella is unlikely to live happily ever after in the form in which we know her. Film and television archivists already know that their original philosophy of preserving images in their original format and support must come to an end sooner or later. Ultimately they must decide between ‘content’, the images and sounds, and the original technology (and of course they will choose the content). However, many of the current digital preser- vation policies seem just as doomed. They are, at this time, too costly, too time consuming, too inconvenient and too impermanent to be realistic.

Cinderella needs her fairy godmother.

157