Once you can read something from the disk (especially pertinent for HDDs), I recommend using `ddrescue`, at least on unixes including MacOS. It will dump as much of the disk as it can, and only then will repeatedly go over the unreadable sectors in hopes of extracting something from them. This approach prevents botching the whole disk by plowing the dead sectors while the rest is still readable. And it can be enough for something like photos and media where some lost kilobytes don't mean much.
Not only will ddrescue do that, but if you re-record that information on another CD or DVD, ddrescue can add extra error-correction information that'll make it easier to recover your data from that media in the future, if it ever gets damaged.
I think you're thinking of dvdisaster, whose site is defunct, though it's been forked on GitHub. I'd suggest par2 instead, as you can separate the recovery files from the media.
You're right. I was thinking of dvdisaster. My mistake.
However, par2 is not a substitute for it, as without the kind of ECC that dvdisaster puts on the CD/DVD, the files on it might not even be readable, so the par2 files on it would themselves be inaccessible, making them worthless.
When I mentioned separating the recovery files, I meant "burn them on the media and also copy them somewhere else." I think par2 can pull data from a re-ripped iso even without, say, legible file names.
I think it should work with anything that functions as a disk device in the system. The program itself likely doesn't do much guessing about sector sizes and such, and just uses smaller and smaller read blocks where larger ones can't be read.
It also doesn't know anything about file systems, simply dumping the disk as an image. After that you work with the image, mounting it, rummaging in it with data-restoring tools, or writing to another disk. This minimizes the chance that the original disk kicks the bucket while you're in the middle of the restoration process, or at least the damage from such misfortune.
Every dad knows you gotta get a SkipDr cause those kids will scratch the crap out of those Disney DVDs. That thing works like magic and is fast and easy to use.
