Multimedia in Web

Introduction

Multimedia Elements in Web Page

ImagesVoiceMusicAnimationVideoText & Numbers

Digitalization

Contents Numbers (0’s & 1’s)For computers and the InternetDifferent media originated and

developed differently, e.g. sound & image Different formats

Accessibility: http://www.w3c.org/WAI/

Pixels

Picture element Values in color and brightness

Role of Bandwidth

Volume of data can transmit in one second

56K (Dial-up)ISDN 128 Kbits/secDSL and Cable (Broadband)

512 Kbits/secT1 1.5 Mbits/secEthernet 10-100 Mbits/sec

Data Compression

Digitalization Compression Decompression

Codecs = Compression + DecompressionRemoving repetition:

e.g. 405 405 405 405 405 405 X 5

Averaging: e.g. 378 379 378 376 378 X 4

Range Reduction: e.g. 8 bit (256) 6 bit (64) Sound loudness can be expressed in 256

levels or 64 levels.

File Formats

ImagesGIFJPEGPNG

SoundAIF (Audio Interchange File)QuickTime

VideoQuickTime (mov)Window MediaRealVideo

AnimationFlash

Viewer Capacity Consideration

Bandwidth Speed test at http://sea.speakeasy.net/

Screen size & resolution 640 X 480 pixel screen

Processor Video System, Ram, & BUS Firewall Plug-Ins: e.g. Flash Player Browser

Experience

Find types of images usedGo to http://www.moma.org/Right-click on images Properties

Movies: http://www.atomfilms.com/ http://www.ifilm.com/