The Digital Video Disc (DVD) is today’s most popular optical storage media. Although the physical dimensions of the DVD is same as the Video Compact Disc (VCD), its capacity for storage makes it a powerful and robust medium.
DVDs are available in two formats – the ‘minus’ or ‘dash’ format and the ‘plus’ format. DVD-R and DVD-RW belong to the ‘minus’ format, while the DVD=R, DVD+RW and the DVD+R DL belong to the ‘plus’ format. The official specification of the DVD is the prerogative of the DVD Forum, which consists of several international organizations. The DVD Forum was founded in 1995, and its members include several software, hardware, media and content companies.
The software used in a DVD for burning, reading and data piracy protection is complex, and serves the industry in several ways. For example, unlike a VCD, the ability of others to copy a DVD can be regulated. This and many such value-added features make DVDs the best storage media so far.
The DVD software deters disc-to-disc copy of sensitive and copyrighted material like movies and audio albums. This is because DVD-Video and DVD-Audio discs are protected by Content Scrambling System (CSS) software, which is followed by the Content Protection for Prerecorded Media (CPPM) software. This software makes DVDs powerful enough to control piracy and copyright violation.
Similarly, the reading of the data on a DVD also entails the use of some special software. Only the DVD playback systems that are licensed can undertake the selective decryption of a DVD. The critical information required to unlock the DVD content is placed in regions that are protected. These regions are accessible to DVD players that have a careful regulation of circumstances. An unlicensed system and absence of the right keys makes the video or audio files inside the DVD unusable. Undertaking a bit-for-bit duplication, as is common in VCDs, does not yield a useful reproduction.
DVD software also carries region management information. This means that DVD players containing the software code of a particular geographical region is only allowed to play the DVDs with that region’s code. If the region’s code is absent, the DVD player cannot play the DVD. Although optional, this facility enables movie publishers to control the distribution of movies and prevent piracy and copyright violation.