DVD+R DL Information

DVD+R DL (Digital Versatile Disc, Recordable Dual Layer, plus format) is an optical storage format that's an extension of the DVD+R format and engineered by the DVD+RW Alliance in competition for market dominance with its DVD-R DL rival. The recordable dual layer disc, also known as the DVD+R9 was introduced in 2003 by Philips and MKM.

DVD+R DL can hold approximately 8.5 GB of data, which equates close to 240 minutes of audio and video storage. It's suited for write-once storage at almost double the capacity of a single layered disc. The disc's characteristics make it versatile for professional and consumer uses, especially for archiving purposes.

Structure of a Dual Layer DVDLike its dash competitor, the DVD+R DL has two recordable dye layers. The disc's reflective layer launches the laser's light to the lens to comprehend the signal. The DVD drive records on the first recordable layer by starting in the center and spiraling outward.

When the first layer is filled with data, the laser shifts to the second recordable layer and writes starting at the rim and spiraling inward to the disc's hub. This orientation path is known as Opposite Track Path (OTP). Consequently, the layers share both a lead-in (boundary at which recording is available to start) and a lead-out (boundary at which recorded data ends).

The drive's laser shift between layers can be distinguished by the technology's user as a few moments of pause. This is no defect, rather the nature of the recordable dual layer disc.

DVD+R DL differentiates itself from DVD-R DL in its efficient built-in system of lossless linking. This feature will optimize a user's storage space and random access to tracks through its encoding at variable bit rate.

The recordable plus disc format is backward compatible with various DVD-ROM drives, DVD players and consumer DVD electronics as long as they support dual layer technology. The price of dual layer drives is now comparable to single layer drives in today's market.

Furthermore, the development of hybrid drives and players that will read or record both plus and dash DVDs has contributed to closing the competitive gap between formats.

Further reading: DVD+R DL White Paper by Andy Marken, 2004.

Be sure to check out our pages on these other DVD formats:

DVD Overview

Web this site