IT2002: MULTIMEDIA SYSTEM DESIGN

Issues In Multimedia Authoring & Design

Objectives

Upon completing this chapter, you should be able to:

Understand the theory and concept of multimedia authoring

Differentiate between the Multimedia Authoring Metaphors

Address the Content Design Issues Understand the Visual Design Issues Be aware of the Technical Design Issues Foresee the Fundamental Design issues

Multimedia Authoring

Multimedia Authoring

Multimedia Authoring the process of creating multimedia application. During authoring, you might need to organize or edit the elements of your multimedia project, create user interface and designing interactivity. This can be achieved through the use of authoring programs / tools.

Why would anyone want to use an authoring program?

Why it is more efficient and effective to use an authoring system: Simplify the inherently complex task of

creating interactive multimedia. Reduce the time needed to develop the

application Increase productivity Reusability of the content e.g. graphics,

animations, audio, video clips.

Authoring Tools

Multimedia authoring tools are the central integrative tools use to combine all the media resources within a structured framework.

Important to select an authoring tool that best suits project needs.

There are a number of factors that will narrow the range of choice : the hardware available for development and

delivery the nature of the multimedia project price the market penetration of the tool.

Authoring & The Metaphor Used Authoring metaphor == authoring

paradigm for easier understanding of the methodology employed to create multimedia applications.

a) Scripting-language metaphorb) Slide show metaphorc) Hierarchical metaphord) Iconic/Flow-control metaphore) Frames metaphorf) Card/Scripting metaphorg) Cast/Score metaphor

a) Scripting Language Metaphor uses a special language to enable interactivity

(button, mouse, etc), and to allow conditionals, jumps, loops, functions/macros

e.g., OpenScript in Toolbook by Asymetrix

-- load an MPEG fileextFileName of MediaPlayer “theMpegPath” = “c:\windows\media\media.mpg”;-- playextPlayCount of MediaPlayer “theMpegPath” = 1;--if want to start and end at specific framesextSelectionStart of MediaPlayer “theMpegPath” = 103;

Example of OpenScript

b) Slide Show Metaphor

by default a linear presentation However, tools exist to perform

jumps/hyperlink – seldom used e.g., PowerPoint, ImageQ

c) Hierarchical Metaphor

User-controllable elements are organized into a tree structure.

Often used in menu-driven applications

d) Iconic/Flow-control Metaphor graphical icons are available in a toolbox Authoring proceeds by creating flow chart with

icons attached. e.g., Authorware by Macromedia

e) Frames metaphor

As in iconic/flow-control metaphor, but uses C language as the programming language rather than represent the actual flow of the program, links between icons are more conceptual

f) Card/Scripting Metaphor

index-card structure, good for hypertext/hypermedia

e.g., SuperCard, HyperCard by Apple

g) Cast/Score/Scripting Metaphor with cast members,

music scores, and scripting language;

many synchronous horizontal "tracks" simultaneously shown in vertical columns;

e.g., Director by Macromedia (Uses Lingo = scripting language)

Content Design Issues

Content Design Issues

"In multimedia, there are five ways to format and deliver your message.

You can write it, illustrate it, wiggle it, hear it, and interact with it." -- D.E. Wolfgram (author of, ‘Creating Multimedia Presentations’)

Scripting

A) Scripting (writing)Rules for good writing:1. Understand your audience and correctly

address them. 2. Keep your writing as simple as possible.

-- e.g., write out the full message(s) first, then shorten it.

3. Make sure technologies are used to complement each other.

Graphics

B) Graphics (illustrating) Make use of pictures to effectively deliver

your messages. – as in the old adage, "A picture is worth a thousand words."

Create your own material (draw, scan, PhotoCD, ...), or keep "copy files" of art works.

Color Themes -- be consistent with the contents pastels (pale or light colors) earth tones metallic colors

Animation

C) Animation (wiggling)Types of Animation Character Animation -- humanize an

object e.g., a toothbrush, a car, a coke bottle, etc.

Animation

Factors in choosing a character Emotion -- Is it happy, sad, funny,

sloppy, ...? Movement -- Is it fast, slow, bumpy, ...? Visual style -- Is its color/texture

consistent with the rest? Copyright -- "Don't use Mickey Mouse

before checking with Disney." Adequacy -- e.g., Does it provide various

poses? (can't make a broomstick sit!)

Animation (Effects & Transitions) Highlights and Sparkles e.g., to pop a word in/out of the screen, to

sparkle a logo --> to draw attention Moving Text e.g., put up one character at a time like a

typewriter OR "pulsing" -- the word grows/shrinks (or changes color) a few times – the typewriter effect can be used to create a suspense atmosphere as well of slowly revealed info.

Note: Do not slowly move entire line of text, they are not easily readable. Instead, for example, slide the bullets in and out.

Video

Video -- live video or digitized video +Advantages more powerful than still images often easier to obtain than graphics

animation - Disadvantages takes a lot of disk space sometimes needs special hardware (depends

on compression used) but more often, requires a codec (Electronic equipment) to be installed to play the particular video.

Audio

D) Audio (hearing)Types of audio in multimedia

applications Music -- sets the mood of the

presentation, enhances the emotion, illustrates points

Sound effects -- to make specific points, e.g., squeaky doors, explosions, wind, ...

Narration -- most direct message, often effective

Interactivity

E) Interactivity (interaction) Interactive multimedia systems are

important Studies have shown that people

remember 70% of what they interact with (Edgar Dale – Cone Of Learning)

Interactivity

Some Common Types of Interactive Multimedia Applications:Menu-driven programs and presentations Hypermedia Simulations/Performance-dependent Simulations e.g., Games -- SimCity, Flight Simulators Video-conferencing (NetMeeting, etc.)

Visual Design Issues

Visual Design Issues

There are a few issues with regard to visual design that must be considered : Themes/Styles Graphic Styles Animation Styles Pace & Running Length Basic Layout/User Interface

Themes & Styles

1. Themes & Styles -- A multimedia presentation should have a consistent theme/style; it should not be disjointed and cluttered with multiple themes. The choice of the theme/style depends on the styles and emotions of your audience.

Various themes can be used for interface

design

Various themes can be used for interface

design

Themes & Styles (Examples)Cartoon theme interesting/entertaining must be consistent with the character's

personality perhaps suitable for an audience of childrenTraditional theme straightforward marketing pieces simple, often informative not as interesting

Themes & Styles (Examples)Hi-Tech theme contemporary computer art work (morphing,

texture mapping, metal texture, explosions, ...) attractive, easy to animate Technical theme include blueprints, 3D models of the product, ...

e.g., start with a drawing, then transformed into a rendered image.

shows adequate technical information gives impression of solid design and

construction

Graphic Styles

2. Graphic Styles Some colour schemes (e.g., natural and

floral for outdoor scenes) and art styles (e.g., oil paints, watercolours, colour pencils, pastels) are best combined with a certain theme/style.

http://www.pibweb.com/review/giveaway/interface.jpg

Graphic Styles

Color Principles and Guidelines Do not use too many colors! Be consistent with the use of color Use colors to separate ideas and signal

changes Fonts Size: e.g., Use large fonts (e.g., 18 to 36

points), no more than 6-8 lines per screen – depends on the application.

Style: -- e.g., serif vs. sans serif

Animation Styles

3.When to Animate ?

"A leaf doesn't flutter if the wind doesn't blow."

Only animate when it has a specific purpose or is necessary

for the application

Using Animation

Enhance emotional impact e.g., dove softly flapping its wings --> peace e.g., air bag explosion + dummy movements --> car crash.

Make a point e.g., show insertion of a memory chip onto the motherboard (much better than a diagram)

Using Animation

Improve information delivery e.g., "pulsing" words (in and out of screen) adds emphasis

Indicate passage of time e.g., clock/hourglass --> program still runninge.g., animated text --> to prompt for interaction/response

Animation Transitions

Some transitions Wipes -- e.g., L-to-R, T-D, B-U, diagonal,

iris round, centree to edge, etc. Dissolve -- the current image distorts into

an unrecognizable form before the next clear image appears, e.g., boxy dissolve, cross dissolve, etc.

Fade -- a metaphor for a complete change of scene

Cut -- immediate change to next image, e.g., for making story points using a close-up

Pace & Running Length

4. Pace and Running length A few guidelines: Allow a block of text to be slowly

read twice. Transition time should be taken

into account for the total running time

Pace & Running Length

Running length (generally) self running presentation: 2-3 minutes limited interaction: 5-6 minutes complete analytical, hands-on demo:

< 15 minutes with questions, discussions: > 30

minutes

You should implement built in breaks for long presentations

Basic Layout

5. Basic Layout make sure that the information delivery

path in the layout is smooth, not irregular or jumpy

chronological (what naturally comes first, should be placed first; e.g. 1980 before 1985)

use headlines/subtitles, additional shapes, buttons, fonts, backgrounds and textures to enhance the visual appearance.

Technical Design Issues

Technical Design

Tech Issues: Technical parameters that affect the design and delivery of multimedia applications Normal Video ModeVideo Mode Resolution Max # Colors CGA 320 x 200 4 EGA 640 x 350 16 VGA 640 x 480 16 or 320 x 200 256

Technical Design

High Color Video Mode

Video Mode Resolution Max # Colors

SVGA 640 x 480 16.7 million *

SVGA 800 x 600 16.7 million *

SVGA 1,024 x 768 16.7 million *

SVGA 1,152 x 864 16.7 million *

SVGA 1,280 x 1,024 16.7 million *

SVGA 1,600 x 1,200 16.7 million *

Note

* The actual number of colors displayed may be smaller, it depends on the amount of video memory on the graphics card. •8-bit color 256 colors •16-bit color 65,536 colors •24-bit color 16.7 million colors

Technical Design

1. Video Mode & Computer Platform PC Macintosh There are many "portable", "cross-platform" software and "run-time modules", but many of them lose quality/performance during the translation.

2. Memory & Disk Space Requirements

Rapid progress in hardware alleviates the problem, but software is too "greedy", especially the multimedia ones.

Technical Design

3. Delivery • Live Presentation • Delivery by diskette

• Small in size, slow to install • Delivery by CD-ROM/DVD-ROM

• Larger capacity• Access time of CD-ROM/DVD-ROM

drives is longer than hard-disk drives • Electronic Delivery (Netshow/Streaming-

video, etc.) • depends on baud rate, network

connection, and monthly bill

Overall Design Issues

Address The Needs

To ensure success the MM system must support multimedia applications that address the diverse needs of users or clients

Architecture and design of the overall systems should cater for these diverse requirements

System Design

Enterprise requirements Technology assessment Business model & related info

Examining current architecture and feasibility

Performance analysis Performance analysis and monitoring Impact of performance issue on design

System Design

Designing for performance Storage management Access management and optimization of

storage distribution Maximizing network transportation Managing system performance

Multimedia System Design Systems Design Methodology Object Oriented Multimedia Systems

System Design

System Extensibility Ease of upgrading / add-on / plug-in Reusability

System Maintenance Routine jobs to upkeep the

operation

Networked MM Systems

Generally, networked multimedia systems have issues to address, some of which are:

Traffic analysis Buffer design Traffic shaping Admission and congestion control Scheduling Standardization