G64PMM - Lecture 2.1
Multimedia Authoring
Systems
Implementation Strategy
 Low level (ie 3GL)
eg C++, Java etc
 RAD Systems
eg Visual Basic, Delphi etc.
 High level (authoring systems)
eg Flash, Director, Authorware, Camtasia etc.
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Low Level Multimedia
Programming
 Advantages
 Flexible / Powerful
 Fast software
 Disadvantages
 Development overhead
 Often removes designers from the development process
 May be expensive to develop and maintain
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RAD Tools
Rapid Application Development
Hybrid systems
combine elements of conventional programming with
high level authoring systems
Best (worst?) of both worlds!
Microsoft Visual Basic (VB)
Borland Delphi
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Visual Basic
Evolved from MS Basic
Visual front end - “authoring system”
Fully Object Oriented VB.NET
Non-portable (ie only Windows)
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Delphi
Turbo Pascal (ie extended object pascal)
Visual front end - “authoring system”
Fully Object Oriented
True compiler
Windows only
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Multimedia Development using
Authoring Systems
Authoring systems allow the selection of preprogrammed elements for multimedia
development
Vary widely in capability, flexibility and ease of
use
Generally easier to use, but less flexible, than
low level languages or RADs
There is an increasing overlap in capabilities
and flexibility
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Use of Authoring Systems
May dramatically reduce development time (and
thus cost)
Often accessible to designers and other “nonprogrammers”
Invaluable for rapid prototyping
Does not affect time spent upon content creation
or media processing
May or may not be useful for final implementation
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Authoring Systems
Distribution
Development
Distributable
Run-time Engine
Development
Environment
Proprietary
Data File
Media
Media
Media
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Authoring Systems
Distribution
Stand-alone program file
Distributable
Run-time Engine
Proprietary
Data File
Media
Media
Media
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Paradigms of Authoring
 Scripting language
 Slide show
 Hierarchies
 Iconic flow control
 Frames
 Card scripting
 Cast/score scripting
 Hypertext
 Embedded markup
 Extended productivity tools
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Scripting Languages
Very common
Resemble conventional programming languages, but
much higher level
For example OpenScript in Toolbook
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Slide Show Metaphor
Slides shown in linear sequence
Some slide show tools allow links and branching
(e.g. menus)
Most slide show tools are controllable by
scripting
MS Powerpoint is the best known example
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Screen Capture Tools
Camtasia Studio probably the best example
Work well with slide shows
Useful for software demos and training
Can be moderately interactive and create
sophisticated multimedia
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Hierarchy
Elements of the system are organised into a
multi-level tree structure
Most suitable for menu-driven applications
For example, common in DVD authoring systems
(e.g. Apple DVD Studio Pro)
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Iconic / Flow Control
Icons are assembled on the screen into a flow chart
Icons represent functionality
Icons are selected from a palette and arranged onto a
flow-line
Behaviour of the icons can then be adjusted
Development tends to be very rapid (at least for simple
interaction)
Runtime tends to be slow
For example Authorware
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Frame Paradigm
Similar to iconic flow control
Frames (icons) are media objects which are
controlled by attached events
Links between icons represent conceptual
associations rather than the flow of the program
An example is Quest
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Card / Scripting
The oldest multimedia authoring paradigm
exemplified by Hypercard
Still important today (e.g. Toolbook)
Flat field database of “cards”
Each card represents a screen display
A stack of cards is controlled by a script
NB the scripting language of Hypercard is
Hypertalk
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Cast / Score / Scripting
Time is represented horizontally
Metaphor is that of a music score or a play (i.e.
actors on a stage)
Multimedia elements are chosen from a “cast”
Scripts control interaction and handle events
Examples are Director and Flash
(Scripting languages are Lingo and Actionscript)
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“Hyperwordprocessors”
Development tools for hypertext
A collection of interconnected documents
Interconnections being links and/or inclusions
The browsing paradigm is fundamental
WWW is hypertext – sort of!
Various authoring systems
All of the extant systems are web front-ends – eg
Dreamweaver
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Extended Productivity Tools
Many productivity tools are programmable and
multimedia capable
Visual Basic for Applications (VBA)
Most MS products
Cross platform (Windows / Mac)
Combines multimedia capability with that of the host
tool
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Mixed High / Low level
development
Most authoring systems can be extended with
custom code written in a conventional programming
language.
This adds power, speed and flexibility
Windows - Dynamic Link Libraries (DLL) or ActiveX
controls
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