Do you guys know of any software that gives accurate information about what's needed to do a proper test?
This is where it gets tricky: Doing a "proper test" is harder than you might think: Error correction capabilities vary significantly from drive to drive. What one drive reports as unreadable or marginably readable may be perfectly readable in the next drive. Most importantly, the results of all C2/PIF error reporting methods are functions of both the disc and the drive. They report areas where that specific drive
had problems reading the data. You can see a lot of varibility between drives in C1/PI/PIF error levels, though C2/POF tend to be less variable.
Therefore it is not possible to get a truly objective report of the disc's readability using consumer DVD-ROM or DVDRw drives.
Or is that even needed - are there drives where scandisc either won't work or will give inaccurate results? If it's inaccurate is it a problem of false-positives, false-negatives or both?
If the CD/DVD scandisc function can't operate, it will give the user an error message. But the File Test option will always operate, assuming the disc is unlocked, and this is guaranteed find any data that that specific drive
can't read. This could lead to false negatives if the drive had particularly good error correction. Aside from the 'unlocking' issue, the only false positives on DVDs I've seen were fixed through cleaning the disc, though I have seen them on CD-R discs on the last sector of an open multisession disc.
At worst, the File Test will give the user the name of a VOB file that might be bad. They can play to find any area with glitches. If problems are found and are replicable on multiple playback devices, IMO it is a real error. If not, then it could be some drive-specific issue, or the disc is of marginal quality.
"True" disc analyzers that take more "objective" measurements like BLER (block error rate) are traditionally found only in professional laboratories, though the Clover Systems DVX
looks promising and relatively inexpensive. It is on my wish-list of things to purchase.