The present device relates generally to portable storage media and more particularly to optical storage arrangements and systems.
One of the most common optical disc storage systems used with data processing systems is the compact disc (CD) disc. A CD provides a read only optical storage medium onto which data is written only once and then read many times. A CD disc can contain a mixed stream of digital image, audio, video, and/or text data. The compact disc typically has a lead-in area, a program area and a lead-out area. The lead-in area is located on the inside of the disc and the lead-out area is closer to the perimeter of the disc. The program area of the disc usually contains digital audio or data that is read by the CD player or the CD-ROM drive.
The CD standard also incorporates the concept of multiple session media. In one example, the first session is a digital audio session and the second session is a xe2x80x9cdata session.xe2x80x9d The data session contains content readable only on a CD-ROM drive and not by a CD player. This recording approach is an example of a more-recent storage media being backwards compatible with existing CD players, providing new data session features to new-generation storage media players. In moving between sessions recorded on the compact disc, such as from the digital-audio session to the data session, the optical reader uses a pointer located in the current session that indicates where the next session starts. The final session on a disc may include a xe2x80x9cnext-sessionxe2x80x9d pointer; if this pointer exists, it points to a non-existent session that may be recorded at a later date. If there is no next-session pointer, then no additional sessions may be appended.
Even though CDs are a popular choice for consumers, the increasing storage requirements of today""s complex graphics and live video are pressuring manufacturers to favor the new, digital versatile disk read-only-memory (DVD-ROM) disks. DVDs operate at higher speeds than their predecessor and provide a storage capacity of about 4.7 GB to 17 GB, which is at least eight times the storage capacity of a typical CD. DVDs have increased dramatically in popularity due to the DVD""s capability to store most feature length films on one disk. However, as movie and video game graphics continue to increase in complexity, the on-going challenge is to provide ever increasing amounts of storage space on the DVD while preserving the current DVD packaging size.
Various aspects of the present invention are directed to increasing the programming versatility of DVDs. The present invention is exemplified in a number of implementations and applications, some of which are summarized below.
According to an example embodiment of the present invention, a dual-layer data disk is adapted to store data in each of two layers, which is readable by an optical disk reader. The disk includes: a first data region for a first logical disk and a second data region for a second logical disk. Each of the first and second regions is arranged on each of the two layers, and each of the logical disks includes a lead-in region and a lead-out region and is adapted for data therebetween traversing each of the two layers. The lead-out region of the first logical disk stores pointing data that points to the lead-in region of second logical disk.
Various applications of the present invention are directed to OPT (Opposite Track Path) and PTP (Parallel Track Pitch) formats. For example, for OPT, there is one logical disk that is split across the two layers on the disk, plus there is an intermediate (or middle) region at the splicing-point of the data; and for PTP, there are two logical disks, two lead-ins, two lead-outs and no intermediate regions.
In related embodiment of the present invention, the lead-out region of the first logical disk is adapted for storing encrypted pointing data which, when unencrypted, points to the lead-in region of second data logical disk. The second region includes data that is application specific, and the first region includes data for xe2x80x9cgeneral consumptionxe2x80x9d across a range of application systems. The first region can also be data-writable for post-production recording of data as another data logical disk.
The above summary is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and detailed description that follow more particularly exemplify these embodiments.