Format Considerations in AudioVisual Preservation Reformatting: Snapshots form the Federal Agencies Digitization Guidelines Initiative

Introduction

Digitization practices have developed and matured in phases. Documents, books, and photographs were among the first items to be digitized by memory institutions— roughly speaking, beginning in the 1980s—and the practices for making still images from these source materials are reasonably mature. The digitization of sound recordings made headway in the late 1990s, with the last decade bringing good levels of consensus on the best approaches to use. Although mature, however, the practices for creating still images and digital audio continue to be refined. Meanwhile, practices for the preservation digitization of moving image content—at least in our memory institutions—are still in their infancy.

Using examples from the Federal Agencies Digitization Guidelines Initiative, this article will provide a few snapshots of digital reformatting practices with an emphasis on formats as they continue to evolve and, for moving images, as they begin to emerge. The federal agencies initiative has two Working Groups. The Still Image Working Group is concerned with the reformatting of books, manuscripts, photographs, maps, and the like, while the Audio-Visual Working Group is concerned with sound recordings, video recordings, and motion picture film. This writer coordinates the Audio-Visual Working Group and the description that follows concerns recorded sound reformatting (with a glimpse of the still image environment) and the group’s exploration of moving image content.

“What formats do you recommend?” That is a question we often hear and, more often than not, people expect a threeletter answer, e.g., wav, mpg, or mxf. Alas, just naming a file format only begins to answer the question. In addition to the file format as container—what the three letters point to—we must attend to the encoding of the data within the container, its organization, and its internal description. My use of the terms format and formatting is in sync with the usage of the Library of Congress Format Sustainability website. (See the What is a Format page.)

The work of the Federal Agencies Working Groups is currently focused on files. All reformatting activities produce files and this common ground makes a good fit for interagency deliberations. Members of both Working Groups, to be sure, understand the importance of digital resources comprised of multiple files: packages in the parlance of the Open Archival Information System. Searchable access to digital resources is often provided at the package level. In a library setting, packages often correlate to what are called manifestations in the terminology of the Functional Requirements for Bibliographic Records (FRBR). Library cataloging typically describes content manifestations. In an archive, digital packages generally correlate to an item in, say, an EAD (Encoded Archival Description) finding aid, where items are typically part of series and collections or record groups. However, the practices for packaging digital resources vary so much from agency to agency (and even within agencies) that we decided “files first, packages later.”

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