Blu-ray Variants

AVCREC

AVCREC is an official lower capacity variant of the Blu-ray Disc used for storing Blu-ray Disc compatible content on conventional DVD discs. AVCREC is being promoted for use in camcorders, distribution of short HD broadcast content and other cost-sensitive distribution needs.

It is important to note that AVCREC is not the same as AVCHD (Audio and Video Compression for High Definition) content stored on DVD. The latter is a media independent format and is used presently in tapeless camcorders that record onto DVD and Blu-ray Discs, as well as onto MemoryStick and SecureDigital memory cards. Playing back AVCHD content on a Blu-ray player may require modification of AVCHD directory structure, but does not require re-encoding of video files themselves.

BD9/BD5 Blu-ray Disc

BD5 and BD9 are lower capacity variants of the Blu-ray Disc that contain Blu-ray compatible audio and video streams contained on a conventional DVD (650 nm wavelength / red laser) optical disc. Such discs offer the use of the same advanced compression technologies available to Blu-ray discs (for example, VC-1, MPEG-2 and H.264/MPEG-4 AVC, while using lower cost legacy media. BD5 uses a standard 4482MB DVD5 single-layer disc, whilst BD9 uses a standard 8152MB DVD9 dual-layer disc.

The BD9/BD5 format was originally proposed by Warner Home Video, as a cost-effective alternative to regular Blu-ray Discs. BD9/BD5 discs can be authored using home computers for private showing using standard DVD±R recorders. AACS digital rights management is optional. The format was adopted as part of the BD-ROM basic format, file system, and AV specifications.

Blu-ray Disc Recordable

Blu-ray Disc recordable refers to two optical disc formats that can be recorded with an optical disc recorder. BD-R discs can be written to once, whilst BD-RE can be erased and re-recorded multiple times.

In September 2007, Mitsubishi and Pioneer co-developed BD-R LTH ("Low to High" in groove recording), which features an organic dye recording layer that can be manufactured by modifying existing CD-R and DVD-R production equipment, significantly reducing manufacturing costs.

The theoretical maximum speed for Blu-ray Discs is about 12x. Higher speeds of rotation (10,000+ rpm) cause too much wobble for the discs to be read properly, as with the 20× and 52× respective maximum speeds of DVDs and CDs.

Mini Blu-ray Disc

The Mini Blu-ray Disc (also, Mini-BD and Mini Blu-ray) is a compact 8cm (~3in) diameter variant of the Blu-ray Disc that can store approximately 7.5 GB of data. It is similar in concept to the MiniDVD. Rewritable (BD-RE) and Recordable (BD-R) versions of Mini Blu-ray Disc have been developed specifically for compact camcorders and other compact recording devices.