Jim Snyder at the festively decorated WCVB-TV Studio
At the Wednesday, December 28, 2016 meeting...
Preserving our Nation’s Audio Visual Legacy Bit-by-Bit
With James Snyder, Senior Systems Administrator, Library of Congress
The challenge of conserving our film and electronic media for future generations was thethoroughly engrossing topic of the SMPTE New England Section’s meeting in December. Our guest speaker, James Snyder, Senior Systems Administrator for the Library of Congress’ National Audio-Visual Conservation Center (NAVCC) in Culpeper, Virginia could very easily be dubbed the “digital media archivist of the United States”.
Snyder, an Emmy Award winning engineer who spent years at ABC (and elsewhere) oversees the effort to preserve and catalog both copyrighted and non-copyrighted film, radio, television and other audio visual material that spans the entire history of our industry’s voluminous output. To a very great extent it parallelsthe hundred year history of our own organization.
Snyder is a member of SMPTE as well as a member of IEEE, AES, IASA, AMIA and NATAS and has served on many of these distinguished organization’s technical committees.
He and his staff operate out of the 415,000 square foot Packard Campus of the Audio-Visual Conservation Center, a facility comprised of everything needed to digitally record and store not only digital copies but also the original source materials they hail from. The building boasts 124 individual vaults (35 of them climate controlled), 90 miles of shelving--and acquisition equipment for off-air, off-satellite and off-cable content. The government funded facility that only opened in 2007 was actually launched with the financial support of private funding. The David and Lucille Packard Foundation helped provide a substantial portion of the seed money.
Snyder spent much of the evening explaining in some detail the challenges involved in an undertaking of this magnitude. About 80 percent of the center’s materials come from copyrighted materials, the more recent of which comes in the form of digital files (DPX files for motion pictures, for example). Often, the center is the primary source for storage with film companies actually going back to them to retrieve copies when necessary. Older films, including film that was shot on highly volatile and flammable cellulose nitrate stock, is digitally scanned and saved as DPX files with the originals stored in temperature controlled vaults. Nitrate can spontaneously combust and must be stored at low temperatures to both reduce deterioration and prevent ignition. Snyder spoke to the potential seriousness of the situation explaining how once a nitrate fire gets going it pretty much has to burn itself out--being impervious to the most common extinguishing agents including water. Burning nitrate even produces its own oxygen as well as highly poisonous gas. Obviously, great care must be taken when working with this material. Nitrate gave way to safer acetate technologies by about 1950.
Electronic media whetheroriginally analog or already in digital form is converted to a lossless (compressed 2.5:1) JPEG2000 format (reversible 5/3) OP1A in a MXF wrapper and stored on Barium Ferrite tape.
Audio is stored in a Broadcast Wave (BWF) format at 96Khz/24 bit.
Small aerial drone with 4K video camera..
Snyder opined that the (BaFe) medium with its high density properties is still currently best for long term survivability and is more economical than current LTO or optical media. He also espoused the merits of SMPTE 2034, the Archive eXchange Format (AXF). AXF ensures long-term availability of content no matter how technologies may evolve. These days migration to new storage formats can take place every 5-7 years.
When digitizing archival footage metadata must be added to describe technical and processing methods. A digital file is useless unless specific instructions are included on how it must be decoded. In addition to this, metadata for description, cataloguing, provenance and other information must be included.
All efforts are made to store data so it will last long enough to be successfully transferred to future long-term storage technologies. There is currently research underway using both holographic techniques as well as biological media (DNA).
Manufacturers often bring their latest storage technologies to Snyder touting their latest products for long-term storage applications. Snyder has some pretty sophisticated test materials for breaking even the best compression and storage algorithms. Many a vendor has left his office with head down and a firmer resolve to go back to the drawing board.
Snyder is of the opinion that like a good doctor a digital media archivist must first “do no harm.” He contends that digitized content must capture as much of the original signal as technologically possible. “You must verify that files moving through systems have not been damaged.” This is much easier said than done. It takes much painstaking checking at each step along the way.
Also, it’s the ever present problem of longevity that is always the 500 pound gorilla on your back. Content must somehow be playable a hundred years from now.
It’s undeniably an ongoing quest.
Photo Credits: Martin P. Feldman, Chairman, SMPTE New England Section.
Chair, SMPTE New England Section
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