fmt/468 ISO 9660 Disk Image File

[Laurence Roger]

Dear Droid community,

I've to scan fmt/468 ISO 9660 Disk Image Files in Droid to find out if all the files were extracted from the containers. I ask Droid to calculate sha256 to deduplicate files & highlight unique content.

Most of the ISO images are not scanned and the content of the containers is not identified.

I use Droid v6.6.1, I've enclosed a screenshot of how the preferences are set up.

Also enclosed a Droid csv export showing scanned & not scanned ISO images.

Best

Laurence

BL

[Dclipsham]

Hi Laurence,

It seems that many of your files are identifying as the recently added (PRONOM update v108, September 2022), specific variants of ISO that DROID is not yet able to unpack (the underlying library can probably deal with most of these variants, but the internal wiring to associate these identification outputs with the right tooling is not yet there). I had thought there was an open issue to deal with this but I couldn't see one so have raised one now: https://github.com/digital-preservation/droid/issues/946

In the interim, you could try using the V107 DROID signature file: https://www.nationalarchives.gov.uk/aboutapps/pronom/droid-signature-files.htm - this should make your files identify as the original ISO entry, fmt/468 that DROID can unpack, and should hopefully unmask the files within your ISOs.

Alternatively, if you prefer you could keep v112 (which has the benefit of including all the updates since v108), but comment out (or delete) the relevant entries within the XML of the DROID signature file, which you'll find in your user home directory, typically c:\users\<username>\.droid6\signature_files - let me know if you need further assistance with this. The full set of ISO variants are:

* fmt/1738 UDF Disc Image
* fmt/1739 UDF-ISO 9660 Bridge Disc
* fmt/1740 Apple Partition Map Disk Image
* fmt/1741 Apple Partition Map ISO 9660 Hybrid
* fmt/1757 Apple Partition Map - ISO 9660 - UDF Hybrid Disk Image

I hope this is useful,

David

[Dclipsham]

Just to add in case it wasn't clear, if choosing this latter option (commenting out the other ISO entries), I would generally recommend saving this edited signature file with a different name, so you can choose between the official and your custom signature files in the DROID settings menus as needed.

David