Web Based Multimedia

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• Web Based Multimedia

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Hypertext

• Hypertext originated in early multimedia systems
• It is used to link specific text in a document
  with related items
• The related item could be more text, a glossary
  definition, a graphic

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• The hypertext could be nested to many levels
• It removes the linearity of textual material and
  allows users to pursue topics and ideas in a
  natural way.

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Hypermedia

• An extension of hypertext is hypermedia whereby a
  variety of media are linked together in a
  structured way
• A specific item in a document could be linked to
  a graphic, text document, sound clip, movie clip

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Web origins

• The world-wide web grew out of the internet,
  which was originally developed for military and
  academic uses
• The major advance for the WWW was it allowed user
  interaction with loaded pages, mainly through
  the use of hypertext and hypermedia

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• Items on the page could be linked to other pages
  anywhere on the web
• These pages would then be loaded onto the local
  computer and displayed

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HTML

• Documents transmitted in this way over the web
  need to be displayed correctly on the local
  computer
• This is achieved by writing them using a common
  language called hypertext mark-up language (HTML)

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• A web document (web page) is written with a
  mixture of plain text and embedded HTML commands
  (tags) which specify the layout and appearance of
  the page content
• Processing of the tags and displaying the page is
  achieved through dedicated software called a
  browser

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Multimedia on the web

• In the early days of the web bandwidth was
  limited and access times were very poor.
• Now however a number of developments have led to
  the possibility of true multimedia over the web.

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• Transmission, compression, and representation
  techniques have improved significantly in recent
  years
• This allows developers to produce web-based
  systems with rich and extensive multimedia content

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• However user interaction with web-based material
  has been limited to click and load and external
  links are loaded with varying speeds
• The use of Java applets and Javascript code
  allows for the embedding of short programs for
  specific tasks

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Plug-ins

• Multimedia features can be incorporated into web
  pages using extensions to web browser called
  plug-ins
• Plug-ins are available for graphics, sound,
  animation and movies

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Authoring tools

• Manufacturers of authoring packages offer
  plug-ins which allow multimedia presentations to
  be delivered over the web
• The user can interact with the presentation
  through their web browser

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Shockwave

• Shockwave is a plug-in from Macromedia which
  allows web delivery of their multimedia
  presentations
• There are different versions of Shockwave for
  use with Director, Authorware, and FreeHand

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• A Director movies which is to be viewed through a
  browser using the Shockwave plug-in has to be
  saved as a Shockwave movie
• The Director movie is compressed and made ready
  for the web

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Web as a resource

• The Web is a highly effective facility for
  developing and delivering multimedia
  presentations
• It can also be used as an extensive library of
  multimedia components such as images, sound
  clips, movie clips

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Web Sites

• www.macromedia.com
• www.shockwave.com
• www.macromedia.com/software/flash/