Klaus FrankLol, the disk swap trick actually works.
Had a DVD that was not recognised by the OS anymore and I just disassembled the drive, put a working one in, waited for it to spin down, took off the lid replaced the disk, and put the lid back on. Now it dumps the broken one without throwing SCSI errors.
Ok, it only read 93%, but that is already quite an improvement compared to 0...
It's probably the Layerbreak. It failed exactly at the sector where it thought the break from L0 to L1 is.
Let's try this trick again but this time with an DVD that has a longer playtime than the one I want to dump...
I think I now found the correct layer break location. However it also looks like the 2nd layer is not readable anymore....
Yep, have it now confirmed. L1 is no longer readable.
And L0 needed a bit of convincing to be readable.
Also I now learned that the percentage that redumper shows is based upon the metadata the OS probides and not the one it reads "raw" off of the disk.
I've now 3 incomplete dumps all ending at the layer break. I also checked a few secors at random and all of them were broken. So I guess my changes are nearly 0 for being able to read anythign off of it. So skipping that.