Scanning new DVD-ROM, what PI/PO to expect?



Go to a store and purchase a glass-mastered / pressed DVD, bring it home, scan it before it’s ever played, and what range of values would you expect to see from a typical “good” disk?

Are there any “iron clad” / industry standard rules for declaring a disk as bad or excessively corrupt? For the sake of simplicity, we’ll assume that all your scanners produced equivalent numbers.

I have a disk with a 23.7% quality rating and I’d like to know how many people would think of that as “bad” for DVD-ROMs, or is there a completely different testing procedure for these, aside from trying to play them on a standard DVD player?

I’m looking into this because a variety of different programs are failing to back up the disk, but I get different error messages for each. Some are verbose, while others are as simple as “I/O Error”.

Related question: Since copy protection systems often rely on bad sectors and other induced errors, what’s the definitive test for distinguishing hardware versus copy protection errors?