DVD Authoring
Unlike videotapes, which simply play from start to end, video DVDs offer a tremendous amount of flexibility for presenting the material they contain. Menus offer quick access to the desired scene or information; multiple audio tracks offer language choices or commentary soundtracks. Elaborate transitions between different menus and tracks make the video DVD visually appealing. One can even add a slide show or a trivia game to a DVD.
‘Authoring’ is the process of taking the source material for a new video product and turning it into the DVD master. It requires the following activities:
- Structure definition: A video DVD is much like a web: tracks and menus define what the viewer can see, and they are linked by buttons that the viewer can activate with the remote control in order to navigate through the contents. A DVD authoring project usually begins with the definition of the intended structure of the DVD.
- Encoding: The source material that goes into a DVD production can be supplied in a variety of formats: film, video tape (analog or digital), still images (prints or digital), and audio in a variety of different formats. The encoding process takes the source media, digitizes it if it exists in an analog format, and converts it into a format that a DVD player can understand. For video images, this is the MPEG-2 format; for audio, there is a choice between uncompressed PCM stereo audio and a variety of compressed formats (such as multi-channel Dolby Digital and DTS).
- Artwork creation: Background images for menus, short video clips that provide an appealing transition from one track or menu to another, as well as sound effects that go along with these transitions, are created especially for the authoring process, since they are not typically considered part of the main media content of the DVD.
- Scripting: For the highest degree of control over how the DVD media is presented to the viewer, scripts can be created. A DVD script is like a small computer program that controls the playback of content in response to the viewer’s remote control inputs.
Once the DVD master is created, it can be used for duplication (for small quantities) or handed off to a replication facility for mass production of the DVD (typically used for quantities of 300 and up).