I’m trying to figure out a general SIP/AIP architecture for optical media images. For CD-ROMs the images will typically be ISO9660 files, and for audio CDs audio files for each track.
It’s pretty common to have carriers that span multiple volumes, and from an access point I think it would make sense to combine those cases into a composite SIP/AIP. Following a discussion I had about this with a colleague, I’m curious how other institutions are handling this, and if there are any best practices. Below some information I found myself.
Library of Congress Audio Compact Disc METS Profile:
This explicitly takes into account the possibility of composite objects:
The primary physical component of a compactDiscObject is one or more compact discs. (…) When there is more than one disc, the div TYPE=“cd:disc” elements must occur in document order that corresponds to the physical order of the discs (Disk 1, Disk 2, etc.).
The virtual CD-ROM and floppy collection of Indiana University seems take a similar approach, judging by e.g. this METS file:
An alternative approach would be to represent each carrier as one SIP / AIP, and then aggregate the AIPs that belong together using what the OAIS model refers to as an Archival Information Collection (AIC). However I’m not sure how widely used this approach is, and I’m slightly worried it might later complicate things on the access side. But I’d be interested to hear what others are doing.