Multimedia in Web

1
Multimedia in Web

• Introduction

2
Multimedia Elements in Web Page

• Images
• Voice
• Music
• Animation
• Video
• Text Numbers

3
Digitalization

• Contents ? Numbers (0s 1s)
• For computers and the Internet
• Different media originated and developed
  differently, e.g. sound image ? Different
  formats
• Accessibility http//www.w3c.org/WAI/

4
Pixels

• Picture element
• Values in color and brightness

5
Role of Bandwidth

• Volume of data can transmit in one second
• 56K (Dial-up)
• ISDN 128 Kbits/sec
• DSL and Cable (Broadband) 512 Kbits/sec
• T1 1.5 Mbits/sec
• Ethernet 10-100 Mbits/sec

6
Data Compression

• Digitalization ? Compression ? Decompression
• Codecs Compression Decompression
• Removing repetition
• e.g. 405 405 405 405 405 ? 405 X 5

7

• 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.

8
File Formats

• Images
• GIF
• JPEG
• PNG
• Sound
• AIF (Audio Interchange File)
• QuickTime

9

• Video
• QuickTime (mov)
• Window Media
• RealVideo
• Animation
• Flash

10
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

11
Experience

• Find types of images used
• Go to http//www.moma.org/
• Right-click on images ? Properties
• Movies
• http//www.atomfilms.com/
• http//www.ifilm.com/