Available in OS X v10.0 and later.
The IODVDBlockStorageDevice class is a generic DVD block storage device abstraction.
This class is the protocol for generic DVD functionality, independent of the physical connection protocol (e.g. SCSI, ATA, USB).
The APIs are the union of CD APIs and all necessary new low-level DVD APIs.
A subclass implements relay methods that translate our requests into calls to a protocol- and device-specific provider.