DVD data storing

Both CD and DVD discs have equal sizes (diameter, thickness etc.). However, the amount of information they can store is different. These discs are made of the same materials and have the same methods of production.

CDs and DVDs use the same way of keeping information. Both CDs and DVDs have pits and bumps on the data track (the data track represents a path which has certain information). The information is read by a laser.

A DVD disk has several layers, which are made of plastic. All layers have a thickness of 1.2 millimeters. An injection used on a polycarbonate plastic leads to the creation of microscopic bumps. Today's production uses this type of plastic to create different things because it can resist very high and low temperatures.

When layers are made, the bumps appear. Many bumps form one continuous spiral that can include information. After that a spray of a special reflective layer covers the bumps.

Aluminum is applied behind inner layers and semi-reflective gold covers the outer layers. This helps the laser to concentrate through the outer layers onto the inner ones. Then, after applying a protective liquid (lacquer) and pressing the layers, they are treated with infrared light.

DVD Region

The DVD region code identifies a DVD's compatibility with the players typically sold in a particular region. The following graphic shows the approximate location of each region. Region 0 DVDS (or "region free") are compatible with DVD players from any region. The majority of all current titles play only in one specific region.

A bit more about DVD Formats

When DVD technology first appeared in households, users were simply popping DVD discs into their DVD players to watch movies — an attractive option to the then-conventional VCR. But just as compact disc (CD) technology evolved so that users could record and erase and re-record data onto compact discs, the same is now true of DVDs.
With so many different formats — DVD+R, DVD+RW, DVD-RAM, DVD-R, DVD-RW, DVD-ROM — how do users know which DVD format is compatible with their existing systems, and why are there so many different formats for DVDs? The following information sheds some light on DVD's different flavors, the differences between them and the incompatibility issues that the differing technologies have sprouted.

Key Terms To Understanding DVD Formats

• DVD: Short for digital versatile disc or digital video disc, a type of optical disk technology similar to the CD-ROM.

• DVD-Video: A video format for displaying full-length digital movies.

• DVD-ROM: A type of read-only compact disc that can hold a minimum of 4.7GB (gigabytes), enough for a full-length movie.

• Burn: Slang term meaning to write data to a CD-ROM or DVD-ROM.

• Divx: Short for Digital video express, a new DVD-ROM format promoted by several large Hollywood companies. With Divx, a movie (or other data) loaded onto a DVD-ROM is playable only during a specific time frame, typically two days.

 

 

Why Are There So Many DVD Formats?

The crucial difference among the standards is based on which standards each manufacturer adheres to. Similar to the old VHS/Beta tape wars when VCRs first hit the markets, different manufacturers support different standards. Often called a format war, both the industry and consumers are still waiting to see which format will emerge as the industry standard.

Plus or Minus - What's The Difference?

The different variations on the term DVD (e.g. +R, -R, -ROM, and so on) describe the way data is stored on or written to the disc itself. These are called physical formats.

DIGITAL VERSATILE DISC, OR DVD

A DVD (which means Digital Versatile Disc or a Digital Video Disc) is an optical disc capable of storing up to 4.7 GB of data, more than six times what a CD can hold. DVDs are often used to store movies at better quality than a VHS. DVDs can also have interactive menus and bonus features such as deleted scenes and commentaries. Like CDs, DVDs are read with a laser.

The disc can have one or two sides, and one or two layers of data per side; the number of sides and layers determines how much it can hold. A 12 cm diameter disc may have one of the following storage capacities:

• DVD-5: single sided, single layer, 4.7 gigabytes (GB), or 4.38 gibibytes (GiB)

• DVD-9: single sided, double layer, 8.5 GB (7.92 GiB)

• DVD-10: double sided, single layer on both sides, 9.4 GB (8.75 GiB)

• DVD-14: double sided, double layer on one side, single layer on other, 13.3 GB (12.3 GiB)

• DVD-18: double sided, double layer on both sides, 17.1 GB (15.9 GiB)

There are also 8 cm DVDs with a storage capacity of 1.5 GB.

The capacity of a DVD-ROM can be visually determined by noting the number of data sides, and looking at the data side(s) of the disc. Double-layered sides are usually gold-colored, while single-layered sides are usually silver-colored, like a CD. One additional way to tell if a DVD contains one or two layers is to look at the center ring on the underside of the disc. If there are two barcodes, it is a dual layer disc. If there is one barcode, there is only one layer.

DVD Studio PRO

DVD Studio Pro was a high-end software tool published by Apple Inc. to allow users to create DVD masters to be sent out for replication at production houses. Its tight integration with other Apple applications allows users to take Final Cut Pro and Motion projects and render them into the DVD format without encoding to intermediary formats. This streamlines the production workflow and reduces overhead. It was discontinued with the release of Final Cut Pro X, Motion 5, and Compressor 4.

Apple bought Astarte's DVDirector in 2000, re-releasing it as DVD Studio Pro in 2001. Version 1.5, still based on this original code, was released in April 2002. In the meantime Apple had acquired Spruce Technologies in 2001, and was busy retooling the DVD authoring package that came with that acquisition (DVD Maestro), and in August 2003, Apple released DVD Studio Pro 2. This new version was basically a completely new application, with a totally new interface. Since then, the program has grown to be the primary midrange software DVD creation package, Sonic Scenarist being the worldwide industry standard for professional DVD authoring.

In April 2005, Apple updated DVD Studio Pro to support authoring HD content. DVD Studio Pro 4 allows for the burning of HD DVD content to both standard DVDs and HD DVD media (even though no HD DVD burners were currently available for Macintosh). For playing back HD DVD content burnt to a standard DVD, Apple requires a PowerPC G5, Apple DVD Player v4.6, and Mac OS X v10.4 or later. This was also the first version that did not include support for Mac OS 9.

In January 2006 Apple stopped offering DVD Studio Pro as a stand-alone product, only selling it as part of the Final Cut Studio suite. The 4.0.3 update, released in the same month, upgrades the program to the finalized HD DVD 1.0 specification. It also supports the native H.264 specification. The 4.2 update, which shipped with the Final Cut Studio 2 release, was simply a compatibility update and did not add any major new features.

DVD Studio Pro has a graphical 'map' view, which shows all the menus, tracks and scripts in the project as color-coded tiles, with the connections between them as arrows. New menus, layered menus, scripts and slideshows can be created from this view and arranged; and the item that will play first on the DVD can be set. Assets (i.e. photos, sounds and Motion projects) are imported into the asset manager and can then be dragged and dropped into one or more places within the project (creating a link to the asset rather than duplicating it). Menus can be created with templates, or pre-made buttons, and with the help of dynamic guidelines they can be kept in a grid arrangement.

Other features include:

• Subtitle creation

• Implementation of CSS and Macrovision copy protection for SD DVD's

• Editing of GPRM and SPRM registers

• Disabling certain functions on particular menus

• Creating multiple language versions of a menu

• Creating multiple versions ('stories') of a video project for example, a director's cut

• DVD@CCESS feature for web links in menus

• A range of transition effects to set between menus.

DVD menu's examples

Defining DVD Authoring

DVD authoring is the process of creating a DVD video capable of playing on a DVD player. DVD authoring software must conform to the specifications set by the DVD Forum group in 1995. The complexity of these specifications results from the number of companies that were involved in creating them.

DVD authoring is the second step in the process of producing finished DVDs: Step 1 is the creation of the movie (or programme); Step 2, the authoring, is the creation of user menus, insertion of chapter points, setting autoplay and/or repeat options; Step 3 is the manufacturing (replication) process to mass-produce finished DVDs.

Strictly speaking, DVD authoring differs from the process of MPEG encoding, but as of 2009 most DVD authoring software has a built-in encoder (though separate encoders are still used when better quality or finer control over compression settings is required).

Most DVD-authoring applications focus exclusively on video DVDs and do not support the authoring of DVD-Audio discs.

Stand-alone DVD recorder units generally have basic authoring functions, though the creator of the DVD has little or no control over the layout of the DVD menus, which generally differ between models and brands.