1. Multimedia and The Web

2. Topic What is multimedia? Multimedia elements Graphics format
Animation
Audio
VDO

3. Multimedia
Multimedia refers to any type of application or presentation that involves more than one type of media, such as text, graphics, video, animation, and sound.

4. Advantages and Disadvantages of Using Web-Based Multimedia
Multimedia Web
Static Web

5. Advantages and Disadvantages of Using Web-Based Multimedia
Can address a variety of learning styles
Visual learners
Auditory learners
Material more interesting and enjoyable
Many ideas are easier to convey

6. Disadvantages Development cost Amount of storage space required
Compatibility and download time for Web-based multimedia

7. Multimedia Elements
Text is used to supply basic content, as well as to add text-based menus and hyperlinks
Serif typefaces: more readable, used for large bodies of text
Sans serif typefaces: used for titles, headings, Web page banners
Different typefaces can convey widely different feelings and impressions
Important to select the appropriate font size
When a consistent text appearance is required— such as a logo—a graphical image is used instead

8. Multimedia Elements
Graphics: digital representations of a photograph, drawing, chart, or other visual image
Clip art: predrawn electronic images
Included with some software programs
Available for free via the Web
Can be purchased individually or in collections
Stock photographs: photographs available for purchase
Various graphic formats (TIF, GIF, BMP, JPEG, PNG, etc.)

9. Compression
Lossy
Lossless

10. Compression & Decompression
a method of removing redundant elements from a file to make the file size smaller then it requires less storage space and less time to transmit.
Sometime we refer to (compression/decompression)

11. Lossless VS Lossy Compression
Techniques : Used Mathematical techniques to replace pattern of bits. Nothing loss from compression. Use for Important file that the data can’t loss such as Text Document. E.g. WIN ZIP.
Techniques : Some information are permanently discarded. Used to compress sound, Image, Video files. E.g. JPEG, MPEG.

12. MP3

13. JPEG & MP3 Compression

14. Multimedia File Format

15. Data of each type of file may store and play by different ways
Data of each type of file may store and play by different ways. We call a way of storing data to file as “file format”
A file format is a particular way that information is encoded for storage in a computer file.

16. Multimedia Elements, Cont’d
GIF: graphics format that supports 256 colors, commonly used for Web page line art images
Can be transparent
Can be interlaced
Uses lossless file compression

17. Noninterlace & Interlace
Noninterlaced GIFs are displayed top to bottom at full quality instead.
Interlaced – the image is displayed initially at low resolution, and its quality is progressively increased until it is displayed at full quality;

18. Half of figure downloaded, non- interlaced GIF
Half of figure downloaded, interlaced GIF

19. Multimedia Elements, Cont’d
JPEG: supports true color and is commonly used for photographs inserted in Web pages
Can be progressive
Uses lossy file compression
The amount of compression is specified when the file is saved

20. Multimedia Elements, Cont’d
PNG: designed specifically for use with Web page images
Lossless compression
Can use color palette or true color
Still not widely used
Choosing a graphic format
GIF—typically used for line art (clip art, logos, etc.)
JPEG—typically used for photographs
Select the most appropriate format
For JPEG, balance compression quality and file size

22. Multimedia Elements, Cont’d
Thumbnail image: small image on a Web page that is linked to a larger, higher-resolution image
Used to save loading time since only users who click the thumbnail view the full-quality image

23. Multimedia Elements
Animation: a series of graphical images are displayed in succession to simulate movement
Java applet: small program inserted into a Web page that performs a specific task
Animated GIF: group of GIF images saved as an animated GIF file, inserted in a Web page; images are displayed successively to simulate movement
For more complex animations, developers can use JavaScript or another scripting language
Multimedia authoring software can be used to create multimedia elements

24. Multimedia Elements Audio: sound (music, spoken voice, sound effects)
Can be recorded using a microphone or MIDI instrument; it can also be captured from CDs or downloaded from the Internet
Often played when an event occurs on a Web page or when the visitor clicks a link
Often streaming audio to speed up delivery
Common audio file formats:
.wav
.mp3
.midi
.aiff
.aac

25. Multimedia Elements
Video: continuous stream of visual information broken into separate images or frames to be displayed successively to simulate the original event
Requires a great deal of storage space
Usually compressed to save room
Streaming video is frequently used on Web pages to speed up delivery
Common video formats:
.avi
.mpeg
.mov
.rm

26. .avi – audio Video Interleave format
a standard video file format developed by Microsoft.
.mpeg – Motion Picture Experts Group format
high-quality, compressed video.
.mov – QuickTime format
Developed by Apple
.rm – Real format
Highly compressed format used for streaming video files.

27. Streaming audio or video
Only a small portion of the audio video file is initially downloaded and buffered (placed in memory or temporarily stored on the hard drive), and then the file can begin playing while the remainder of the file downloads simultaneously.
Because it allows the user to see or hear the file’s content significantly faster than if the entire file had to be downloaded first, it is recommended to use the streaming approach for all large audio and video files used with web pages.