Introduction
This document describes the preservation plan for audio content in the McMaster University Digital Archive. The preservation plan for audio content follows from policies and practices described in the Strategic Framework for Digital Preservation and the Digital Preservation Implementation Plan. This document explains practical steps that McMaster University Library takes to preserve the intellectual content of audio in digital format. It outlines the basic tools, methods, and standards used for the long-term preservation of audio content.
Content Formats
For the preservation of audio content, McMaster University Library requires WAV or FLAC versions of the content and descriptive metadata. During the ingest process, derivatives are created to provide easy access to content. McMaster University Library continuously monitors developments in file formats to determine if and when formats require migration (see Environmental Monitoring of Preservation Formats).
SIP Format
Audio SIPs (see Definition of AIP_DIP_SIP) generally consist of a WAV or FLAC file, and an associated MODS descriptive metadata file.
Analysis on Ingest
Upon ingest, every file in the repository is subject to identification of its file format and validation using FITS. The output of the FITS identification and validation processes are recorded to a technical metadata datastream (TECHMD_FITS) that is associated with the object in the repository.
Content Excluded
McMaster University Library does not ingest files that are not referenced (either as part of a representation or as associated datastreams) in the associated metadata. As the SIP is retained, these files can later be ingested if necessary.
Format Normalization
There is no format normalization if the submitted object is a WAV or FLAC.
Metadata Normalization
When necessary, McMaster University Library crosswalks descriptive metadata from MODS to Dublin Core. The repository creates preservation metadata for each file. The preservation level, explained in the Digital Preservation Implementation Plan, is applied to each file upon ingest and recorded in the preservation metadata for each file.
Acceptable Formats
For the Full Preservation level for audio, currently the acceptable formats are WAV and FLAC. Audio submissions may be MP3 format, however they will be preserved at the Bit-level Preservation level.