Security
Main article: Content Protection for Recordable Media
DVD-Audio discs employ a copy protection mechanism, called Content Protection for Prerecorded Media (CPPM) developed by the 4C group (IBM, Intel, Matsushita, and Toshiba).
To date, CPPM has not been "broken" in the sense that DVD-Video's CSS has been broken, but ways to circumvent it have been developed. By modifying commercial DVD(-Audio) playback software to write the decrypted and decoded audio streams to the hard disk, users can essentially extract content from DVD-Audio discs much in the same way they can from DVD-Video discs.
Improvements and succession
In 2006, a new format called Blu-ray Disc (BD), designed by Sony, Philips, and Panasonic, was released as the successor to DVD. Another format, HD DVD, competed unsuccessfully with this format in the format war of 2006 to 2008. A dual layer Blu-ray Disc can store 50 GB.
However, unlike previous format changes (e.g. audio tape to compact disc, VHS videotape to DVD), there is no immediate indication that production of the standard DVD will gradually wind down, as they still dominate with around 97% of video sales and approximately one billion DVD player sales worldwide. Consumers initially were slow to adopt Blu-ray, partly due to the cost. Currently, Blu-ray players are selling for $198 USD, while titles retail for as cheap as $9.86 USD (but are usually significantly higher in price than SD DVD releases, at a more common $20-$30 USD price). A high-definition TV and appropriate connection cables are also required to take advantage of Blu-ray disc. Some analysts suggest that the biggest obstacle to replacing DVD is due to its installed base; a large majority of consumers are satisfied with DVDs. The DVD had succeeded because it offered a compelling alternative to VHS. In addition, Blu-ray players are designed to be backwards compatible, allowing older DVDs to be played since the media are physically identical; this differed from the change from vinyl to CD and from tape to DVD, which involved a complete change in physical medium.
This situation can be best compared to the changeover from 78 rpm shellac recordings to 45 rpm and 33 1/3 rpm vinyl recordings; because the medium used for the earlier format was virtually the same as the latter version (a disk on a turntable, played using a needle), phonographs continued to be built to play obsolete 78s for decades after the format was discontinued. Manufacturers have announced standard DVD releases well into 2009, and the format remains the preferred one for the release of older television programs and films, with some programs such as Star Trek: The Original Series requiring reediting and replacement of certain elements such as special effects in order to be better received in high-definition viewing.
The Holographic Versatile Disc (HVD) is an optical disc technology that may one day hold up to 3.9 terabytes (TB) of information, albeit the current maximum is 250GB. It employs a technique known as collinear holography.