1

Multimedia Systems

Course InstructorSamana Zehra

2

What will be covered today?

Course Introduction Course Objective Contents Resources Grading Policy

Lecture no.1

3

Course Objective

To learn what are … Different forms of multimedia Principles of multimedia processing and

presentation in computers Multimedia applications Multimedia networking

4

Course Contents

Multimedia Basics Multimedia Formats Image Fundamentals Color Science Sound/Audio Video Compression Fundamentals Multimedia Applications Multimedia Networking

5

Resources

Ze-Nian Li & Mark S. Drew, "Fundamentals of Multimedia", Pearson Education, 2004

Steinmetz R & Nahrstedt K, “Multimedia: Computing, Communication & Applications”, Pearson Education, 2001

F. Halsall, "Multimedia Communications: Applications, Networks, Protocols, and Standards", first edition, Addison-Wesley, 2000

James F. Kurose & Keith W. Ross, “Computer Networking – A top-down approach featuring the internet”, Third edition, Pearson Education, 2005

6

Grading Policy

Theory Exam (100 marks) Sessionals (50 marks)

Internal (25 marks) Quizzes (4 to 5) Assignments (2 to 3)

can include presentations

External (25 marks) Viva May include some tasks/presentations

7

Lecture -1

The introduction begins…

8

Introduction

Multimedia definitions:- Multi means many; much; multiple Medium means:

a substance regarded as the means of transmission of a force or effect; a channel or system of communication, information or entertainment (Merriam-

Webster Dictionary)

Medium means: an intervening substance through which something is

transmitted or carried on (American Heritage Electronic

Dictionary) So Multimedia is medium having multiple content

forms.

9

Introduction (Contd.)

Multimedia includes a combination of text, audio, still images, animation, video, and interactivity contentforms.

Multimedia is usually recorded & played, displayed or accessed by computerized and electronic devices, but can also be part of a live performance.

Multimedia also describes electronic media devices used to store and experience multimedia content.( source: Wikipedia )

10

VVO Multimedia-terminal in Germany

A PowerPoint presentation used in a corporate office

Virtual reality uses multimedia content

11

Introduction (Contd.)

Based on time-dimension in the representation space, media can be Time-independent (Discrete)

Text, Graphics Time dependent (Continuous)

Audio, Video Video, sequence of frames (images) presented to the

user periodically. Time dependent aperiodic media is not continuous!!

Note: Discrete & Continuous have no connection with

internal representation.

12

History of Multimedia

Newspaper - perhaps the first mass communication medium to employ Multimedia - they used mostly text, graphics, and images.

1895 - Marconi sent his first wireless radio transmission at Pontecchio, Italy.

1901 - Maroni detected radio waves beamed across the Atlantic. Initially invented for telegraph, radio is now a major medium for audio broadcasting.

Television - new media for the 20th century. It brings the video and has changed the world of mass communications.

Some of the important events in relation to Multimedia in Computing include: 1945 - Bush wrote about Memex 1967 - Negroponte formed the Architecture Machine

Group at MIT 1969 - Nelson & Van Dam hypertext editor at Brown Birth of The Internet

13

History of Multimedia (Contd.) 1971 - Email 1976 - Architecture Machine Group proposal to DARPA:

Multiple Media 1980 - Lippman & Mohl: Aspen Movie Map 1983 - Backer: Electronic Book 1985 - Negroponte, Wiesner: opened MIT Media Lab 1989 - Tim Berners-Lee proposed the World Wide Web to

CERN (European Council for Nuclear Research) 1990 - K. Hooper Woolsey, Apple Multimedia Lab, 100 people,

educ. 1991 - Apple Multimedia Lab: Visual Almanac, Classroom MM

Kiosk 1992 - the first M-bone audio multicast on the Net 1993 - U. Illinois National Center for Supercomputing

Applications: NCSA Mosaic 1994 - Jim Clark and Marc Andreesen: Netscape 1995 - JAVA for platform-independent application

development. Duke is the first applet. 1996 - Microsoft, Internet Explorer.

14

Multimedia Authoring Tools

Multimedia elements are composed into a project using authoring tools.

Multimedia Authoring tools are those programs that provide the capability for creating a complete multimedia presentations by linking together objects such as a paragraph of text (song), an illustration, an audio, with appropriate interactive user control

15

Multimedia Authoring Tools (Contd.) By defining the objects' relationships to each

other, and by sequencing them in an appropriate order, authors (who use authoring tools) can produce attractive and useful graphical applications.

To name a few authoring tools Macromedia Flash Macromedia Director Authorware

The hardware and the software that govern the limits of what can happen are multimedia platform or environment

16

Multimedia and Interactivity

Multimedia is interactive when the end-user is allowed to control what and when the elements are delivered.

Interactive Multimedia is Hypermedia, when the end-user is provided with the structure of linked elements through which he/she can navigate.

17

Multimedia and Interactivity

Multimedia is linear, when it is not interactive and the users just sit and watch as if it is a movie, e.g., cinema presentation

Multimedia is nonlinear, when the users are given the navigational control and can browse the contents at will, e.g., computer game, computer-based training.

18

Multimedia System

A Multimedia System is a system capable of processing multimedia data and applications.

A Multimedia System is characterised by the processing, storage, generation, manipulation and rendition of Multimedia information.

19

Characteristics of Multimedia System A Multimedia system has four basic

characteristics: Multimedia systems must be computer

controlled. Multimedia systems are integrated. The information they handle must be

represented digitally. The interface to the final presentation of

media is usually interactive.

20

Challenges for Multimedia System Supporting multimedia applications over a computer

network renders the application distributed. Multimedia systems may have to render a variety of

media at the same instant; a distinction from normal applications.

There is a temporal relationship between many forms of media (e.g. Video and Audio). In this case problems are:

Sequencing within the media - playing frames in correct order/time frame in video

Synchronisation - inter-media scheduling (e.g. Video and Audio). Lip synchronisation is clearly important for humans to watch playback of video and audio and even animation and audio.

21

Challenges for Multimedia Systems The key issues that multimedia systems need to

deal with are: How to represent and store temporal information. How to strictly maintain the temporal relationships on

play back/retrieval What process are involved in the above. Data has to be represented digitally so many initial

source of data needs to be digitised - translated from analog source to digital representation. This will involve scanning (graphics, still images), sampling (audio/video) although digital cameras now exist for direct scene to digital capture of images and video.

The data is large (several Mb) for audio and video - therefore storage, transfer (bandwidth) and processing overheads are high. Data compression techniques very common.

22

Desirable Features Given the (mentioned) challenges the following

features are desirable (if not a prerequisite) for a Multimedia System: Very High Processing Power

needed to deal with large data processing and real time delivery of media. Special hardware commonplace.

Multimedia Capable File System needed to deliver real-time media e.g. Video/Audio

Streaming. Special Hardware/Software needed e.g RAID technology.

Data Representations/File Formats that support multimedia Data representations/file formats should be easy to handle

yet allow for compression/decompression in real-time. Efficient and High I/O

input and output to the file subsystem needs to be efficient and fast. Needs to allow for real-time recording as well as playback of data. e.g. Direct to Disk recording systems.

23

Desirable Features

Special Operating System to allow access to file system and process data

efficiently and quickly. Needs to support direct transfers to disk, real-time scheduling, fast interrupt processing, I/O streaming etc.

Storage and Memory large storage units (of the order of 50 -100 Gb or

more) and large memory (50 -100 Mb or more). Large Caches also required and frequently of Level 2 and 3 hierarchy for efficient management.

Network Support Client-server systems common as distributed systems

common. Software Tools

user friendly tools needed to handle media, design and develop applications, deliver media.

24

Multimedia Applications

Multimedia finds its application in various areas, a few are: Education

Computer-based trainings, reference e-books, documents imaging, distant learning.

Entertainment Interactive games

Medicine Training to doctors through virtual surgery

Business Employee training, advertisements, customer support,

selling products. Arts

Art exhibitions, literature presentations Scientific Research

Modeling and simulations

25

Multimedia Applications (Contd.)

In Medicine

Source: Cardiac Imaging,YALE centre for advanced cardiac imaging

26

Multimedia Applications (Contd.)

In training

27

Multimedia Applications (Contd.)

Public awareness campaign

SourceInteractive Multimedia Project Department of food science& nutrition, Colorado State Univ

28

Multimedia Applications (Contd.) Other Applications include:

World Wide Web Video conferencing Video-on-demand Interactive TV Home shopping Games Virtual reality Digital video editing and production systems Multimedia Database systems

29