Introduction to Multimedia System

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Chapter II

The Multimedia Sysyem


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What is multimedia?

Multimedia means that computer information can berepresented through audio, video, and animation in additionto traditional media (i.e., text, graphics/drawings, images).

Multimedia can have a many definitions these include:


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A Multimedia Application is an

application which uses acollection of multiple media sources

e.g. text, graphics, images,sound/audio, animation and/or video.

Multimedia Application Definition


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Hypertext is a text which

contains links to other texts.The term was invented byTed Nelson around 1965.

What is HyperText and HyperMedia?


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Traversal through pages of

hypertext is therefore usuallynon-linear (as indicated

below).

This has implications inlayout and organisation of

material and depends a lot on the

application at hand.

HyperText Navigation


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HyperMedia is notconstrained to betext-based. It can

includeother media, e.g.,graphics, images,and especially the

continuous media sound and video.

Hypermedia


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Examples of Multimedia Applicationsinclude: World Wide Web Multimedia Authoring, e.g.

Adobe/Macromedia Director Hypermedia courseware Video-on-demand Interactive TV Computer Games Virtual reality

Digital video editing and productionsystems Multimedia Database systems

Multimedia Applications


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A Multimedia System is a systemcapable of processing

multimedia data and applications.

A Multimedia System ischaracterised by the processing,

storage, generation, manipulationand rendition of Multimedia

information.

Multimedia Systems


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Distributed Networks

Temporal relationship between dataRender different data at same time continuously.Sequencing within the media

playing frames in correct order/time frame invideo Synchronization inter-media schedulingE.g. Video and Audio Lip synchronisation is clearlyimportant for humans to watch playback of video andaudio and even animation and audio.Ever tried watching an out of (lip) sync film for a longtime?

Challenges for Multimedia Systems


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Given the above challenges the following feature a desirable(if not a prerequisite) for a Multimedia System:Very High Processing Power needed to deal with large dataprocessing and real time delivery of media. Special hardwarecommonplace.Multimedia Capable File System needed to deliver real-timemedia e.g. Video/Audio Streaming.Special Hardware/Software needed e.g RAID technology.

Data Representations File Formats that support multimediashould be easy to handle yet allow forcompression/decompression in real-time.

Desirable Features for a Multimedia System


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Now let us consider the Components (Hardware and Software)required for a multimedia system:Capture devices Video Camera, Video Recorder, Audio

Microphone, Keyboards, mice, graphics tablets, 3D inputdevices, tactile sensors, VR devices. Digitising HardwareStorage Devices Hard disks, CD-ROMs, DVD-ROM, etcCommunication Networks Local Networks, Intranets,Internet, Multimedia or other special high speed networks.Computer Systems Multimedia Desktop machines,

Workstations, MPEG/VIDEO/DSP HardwareDisplay Devices CD-quality speakers, HDTV,SVGA, Hi-Resmonitors, Color printers etc.

Components of a Multimedia System


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Examples of Multimedia Applications include: World Wide Web Hypermedia courseware

Video conferencing Video-on-demand Interactive TV Groupware Home shopping Games

Virtual reality Digital video editing and production systems

Applications


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Text and Static Data Source: keyboard, speech input, optical character recognition,data stored on disk. Stored and input character by character:

Storage of text is 1 byte per character (text or formatcharacter).For other forms of data (e.g. Spreadsheet files). May storeformat as text (with formatting) others may use binary encoding. Format: Raw text or formatted text e.g HTML, Rich Text Format(RTF), Word or a program language source (C, Pascal, etc..

Not temporal BUT may have natural implied sequence e.g.HTML format sequence, Sequence of C program statements. Size Not significant w.r.t. other Multimedia data.

A Brief Look at Multimedia Data:


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Multimedia systems/applications haveto deal with the Generation of data,

Manipulation of data, Storage of data, Presentation of data, and Communication of information/data

Multimedia Data Basics


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Diverse Application ofMultimedia

Video Teleconferencing

Distributed lectures

Telemedicine

Augmented Reality

Video Recognition


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Overview of Multimedia Tools

Music Sequencing and Notation

Sequencing and Editing of music/sounds

Digital Audio

Editing of actual sampled sounds that makes up an audio

Graphics and Image Editing

Editing and creating images

Image processing and manipulation

Video Editing

Editing of video (non-linear), used to add special effects

Animation

Used to construct 3D and 2D graphics, animated.

Multimedia Authoring

Tools that provide the capability to create a completemultimedia presentation using interactive controls.

Documents

Introduction to Multimedia System