Session D: Supporting Change in Learning and Teaching
Greenberg : A Hybrid System for Delivering Web Based Distance Learning and Teaching Material
DVD originally stood for Digital Video Disc and was intended for the distribution of video. It now officially stands for Digital Versatile Disc as its uses now include standalone audio and distribution of software and data. Physically it is the same size as a CD-ROM, but the laser beams used are much finer and the rate of rotation of the disc is faster.
This data can be played by any suitable application, but a key part of the DVD standard is that there is a "standard player" which can either be in the form of a standalone (table-top) player connected to a TV or a software player on a computer. The player interprets the data on the disk in a special way to create a substantially interactive experience. This includes multiple camera angles, multiple language audio tracks, multiple sub-title tracks, still pictures and interactive screens (or video) called menus.
There are emerging standards for extensions to this player which allow display of web pages at key points and also to allow web pages to display DVD video in a convenient manner.
DVD authoring consists of encoding video, audio, text data, creating interactive screens and scripts, and organising the arrangement of all these resources on the disk so as to work appropriately with the standard DVD player. After testing this (including the writing of DVD-R discs) then a tape is created which is sent off together with label graphics etc. for the pressing of a large number of DVD discs. Additional software and files can be included on a DVD and these can include software which incorporates the playing of the encoded DVD files in ways not possible with a DVD player.
The DVD-ROM format can be used as a distribution medium, offering up to 15 times the capacity of the CD-ROM. A move from CD-ROM to DVD-ROM and VHS to DVD distribution, would result in a considerable saving to the University as has a move from floppy disk to CD-ROM. The DVD-ROM format in most common use in Europe is DVD-9 which holds around 9GB of data on two layers of a single-sided disc. DVD-18 production is now underway in the USA and this format holds 18 GB on two layers on both sides of the disc.
Recent projections for DVD household penetration in Europe show a growth from 14% in 2000 to around 80% by 2005. DVD-ROM drives are now rapidly replacing CD-ROM drives in desktop PCs and an upgrade to a DVD-ROM drive is now an inexpensive option. DVD-ROM drives are compatible with almost all CD formats including CD-ROM and CD Audio.
The Open University is currently working with two systems: the Spruce Maestro DVD authoring system and the Daikin Scenarist DVD authoring system.
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