For a few years now I have been working on-and-off on a personal project to import data from a large collection of home-made CD-Rs and DVD-Rs. I've started writing up my notes, experiences and advice for performing a project like this; but they aren't yet in a particularly legible state.
As part of this work I wrote some software called "BadISO" which takes a possibly-corrupted or incomplete optical disc image (specifically ISO9660) and combined with a GNU ddrescue map (or log) file, tells you which files within the image are intact, and which are not. The idea is you have tried to import a disc using ddrescue and some areas of the disc have not read successfully. The ddrescue map file tells you which areas in byte terms, but not what files that corresponds to. BadISO plugs that gap.
Here's some example output:
$ badiso my_files.iso … ✔ ./joes/allstars.zip ✗ ./joes/ban.gif ✔ ./joes/eur-mgse.zip ✔ ./joes/gold.zip ✗ ./joes/graphhack.txt …
BadISO was (and really, is) a hacky proof of concept written in Python. I have ambitions to re-write it properly (in either Idris or Haskell) but I'm not going to get around to it in the near future, and in the meantime at least one other person has found this useful. So I'm publishing it in its current state.
BadISO currently requires GNU xorriso.
You can grab it from https://github.com/jmtd/badiso.