A Brief History of DVD

By January 1995, two digital video disc formats had emerged as potential standards:

The Super Density (SD) format by Toshiba and a consortium of partners * The Multi Media Compact Disc (MMCD) by Philips and Sony

With the prospect of another "Beta vs. VHS" format war on the horizon, consumer electronics manufacturers and studios formed the DVD Consortium to agree upon a single unified specification for the next generation compact disc. In December 1995, a general agreement was reached and DVD was born.

DVD stands for "Digital Versatile Disc" but is often referred to as "Digital Video Disc." It is a multiapplication family of optical disc formats for read-only, recordable, and rewritable applications.

A key feature of DVD is that the shelf life of the media is considered much a key feature of DVD is that the shelf life of the media is considered much longer than VHS: 10 years for VHS and 50-300 years for DVD.

DVD discs are the same diameter (120 mm) and thickness (1.2 mm) as compact discs, but that is where the similarities end. A single DVD disc has the capability to store up to 13 times the data contained on a CD, on one side. Because DVDs are capable of utilizing both sides of a disc for data storage, DVD offers 26 times the power of a compact disc.

DVD physical formats include:

DVD-ROM, which stands for Digital Versatile Disc (or Digital Video Disc) Read-Only-Memory. DVD-ROM is an American National Standards Institute (ANSI) standard. It is the base format and can store almost any form of digital data. The amount of data stored on a DVD-ROM is determined by its datadata. The amount of data stored on a DVD-ROM is determined by its data structure. A DVD-5 data structure refers to a single-sided, single-layer DVD disc containing 4.7 billion bytes of data. Data structures include DVD-5, DVD-9 (most movie DVDs use this structure), DVD-10, DVD-14, and DVD-18.

DVD-R is the version of DVD on which data can be recorded one time. DVD-R was originally a single format, but it has been split into DVD-R(G) and DVD-R(A) formats. DVD-R(G) - General - is intended for home or general- purpose use. DVD-R(A) - Authoring - is intended for professional DVD authoring and can be submitted to replication service bureaus. DVD-R(A) media are not writable in DVD-R(G) recorders and vice versa. Both types of media are readable by DVD players and drives. If a DVD video player can read the DVD-R format, it usually doesn't matter whether the disc is DVD-R(G) or DVD-R(A).

The DVD standard includes three erasable variations: DVD-RAM, DVD-RW, and DVD+RW. Discs in these formats can be rewritten many times.

Determining which drives can read/write to which media can be confusing. Take the Apple SuperDrive. It's a DVD-R(G) drive, so it can read DVD-R(G), DVD-R(A), DVD-ROM, and DVD-RW discs. It can write (or burn) DVD-R(G) single-sided discs, as well as CD-R and CD-RW discs. It can write to DVD-R discs too, but additional software (such as Roxio's Toast 5 Titanium) is necessary.

Just as there are physical formats for the media there are also application formats. DVD-Video uses a specific set of file types and data types to deliver high-quality video and audio. DVD-Audio is a separate format from DVD-Video. DVD-Audio is the audio-only format of DVD that primarily uses pulse code modulation (PCM), a method of digitizing audio that uses sampling sizes and rates higher than audio CD. There are other lesser application formats as well, DVD-VR (video recording), DVD-AR (audio recording), DVD-SR (video stream capturing), and formats for game players like the Sony(video stream capturing), and formats for game players like the Sony Playstation.