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Ongoing Considerations in AV Preservation at CUL

In an audiovisual preservation workflow, there is a bit of a wormhole effect to each decision you make. For instance, when choosing whether to accommodate the digitization of a new format in-house, one must consider long-term support for the equipment involved, including cleaning, maintenance, tools and supplies, as well as technical expertise. All of these things add up to two critical things: time and money.

A Studer A810 we recently inherited from our colleagues at the Lab of Ornithology. This deck originally came from NPR Studios by way of Bill McQuay.

A Studer A810 we recently inherited from our fantastic colleagues at the Lab of Ornithology. This deck originally came from NPR Studios and Radio Expeditions’ Bill McQuay.

 

 

 

 

 

 

 

 

 

 

In a preservation workflow, it’s not always as simple as hooking a VCR (assuming you still have one) up to a computer. You might think: If you need a DVD copy of something or a CD dub of an old recording, then that’s fairly easy given today’s technology, right? As with the conservation of a manuscript or painting, there are general requirements and standards widely accepted and used by the preservation community when trying to digitally preserve unique AV content. Instead of scanning an image at high-resolution, rebinding a brittle book, or making a squeeze more interpretable, you’re trying to capture an electric signal. The quality of that signal can make all the difference and consumer grade electronics weren’t designed to produce a broadcast-grade signal.

It first requires routinely tested, cleaned, professional and broadcast-grade equipment. This equipment is not cheap and the cost of the items, parts, and repair expertise is rapidly increasing due primarily to format obsolescence. Legacy formats like magnetic tape are machine-readable and completely reliant on the proper technology to be interpreted. Most of the major manufacturers of magnetic media and the devices needed to play it have disappeared. Next, one must consider the quality of the analog to digital converter. Organizations like The International Association of Sound and Audiovisual Archives(IASA) and the Audio Engineering Society (AES) have set guidelines for the quality of analog–to-digital converters for audio preservation. Standards for video (RF) conversion and digitization are still being worked on by various organizations and institutions. Finally, you need a computer capable of 10-bit (or higher) capture to a linear-based editing software platform. As you can see, deciding to digitize a format in-house is a big one.

We have been carefully considering the formats we want to support in the digitization lab here at CUL. We want to address the major formats contained in our vast collections, balancing what we can achieve on-site with the services available through our vendor partners.

In the CUL AV preservation lab, we can now handle the following formats:

-VHS/SVHS
-U-Matic (3/4”)
-Cassette
-Vinyl LP (33rpm)
-1/4” open reel audio (Stereo and 4-Track)
-DV/MiniDV
-all formats of non-tape based, digital-born audio and video
 

Another huge piece of the puzzle is maintaining the integrity of digital content. After something has been digitized, the work is not finished, as many institutions have learned. There are requirements to maintaining the integrity of this data. Audiovisual data could be lost or compromised due to data loss, bit rot, bit-level corruption, hardware failure and other kinds of data problems. We maintain integrity by utilizing fixity checks in the form of data comparisons on a weekly basis on both of our digitization stations. This helps keep track of additions and changes to files in order to recognize digital problems and errors within our current projects. I hope that we can soon be pushing these preservation master files into CULAR, as we’re running out of space on our 24TB machines. That brings me to the biggest hurdle at this point: video master files are huge. 60 minutes of SD video footage at 10-bit resolution ends up producing a roughly 100GB file.

I knew this coming in, but it’s become clear that deciding what formats to handle in-house and knowing when to outsource is crucial. I have developed close, working relationships with our vendors in order to minimize cost and effort while meeting our format and metadata needs. IT requirements are growing across the library and that is part of the cost burden we have to be mindful of. Danielle Mericle and I are working closely on how to adequately meet CUL’s audiovisual preservation needs while not over-extending our budget, scope, and the library’s general requirements. This is a big charge, but I’m happy to report that we’ve made huge strides toward meeting this challenge.

-Tre Berney

 

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