This report from the Digital Preservation Coalition outlines the unique challenges involved in digitising audio and audiovisual material. ‘Moving image and sound content is at great risk.’ ‘Preserving the quality of the digitized signal’ is one major digital preservation challenge for audiovisual files’.
Understanding how data changes as it is played back, or moved from location to location, is important for thinking about digitisation as a long term project. When data is encoded, decoded or reformatted it alters shape, therefore potentially leading to a compromise in quality. This is a technical way of describing how elements of a data object are added to, taken away or otherwise transformed when they are played back across a range of systems and software that are different from the original data object.