Hier een stukje uit de documentatie van 'DVD Plus Identifier'. Samengevat : als je drive voldoet aan de meest recente specicaties dan kan je het ook uitlezen voor lege discs. Als je drive iets ouder is, is een geschreven disc gebruiken de enige manier om het uit te lezen.
"DVD Plus Identifier" uses 2 different techniques for retrieving the ADIP :
** ADIP retrieval method 1 (Original ADIP)
This is the preferred method for ADIP retrieval since it retrieves the original ADIP from the disc. However, to retrieve the ADIP in this manner a command is used which is only recently introduced in the Multimedia command specification (MMC-4 revision 2a, dated June 9th 2003, to be exact). As a consequence the number of drives that will support this command is currently relatively limited. Nevertheless, all future drives will support this command and older drives will likely include support for this command through firmware upgrades. For example, the Ricoh MP-5125A (a very popular drive which is also shipped by companies such as Hewlett-Packard and Philips) does not support this command with firmware 1.51 but when the firmware is upgraded to 1.64, ADIP retrieval using this method is supported.
If your drive does not support method 1 "DVD Plus Identifier" will attempt to retrieve the ADIP using method 2.
** ADIP retrieval method 2 (Copy of ADIP)
While method 1 also works with empty discs, method 2 requires the use of already written discs (either a DVD+R with closed session or a DVD+RW which is at least partially formatted). Every written disc contains a copy of the disc's original ADIP and with method 2 this copy will be read out instead of the original ADIP. Since reading this ADIP-copy is done by a command which is supported by nearly all drives no drive compatibility issues are expected here. Do note that there are in fact some drives which can handle method 2 even with empty discs.