AFTER COMPLETING THIS CHAPTER, YOU WILL BE ABLE TO:

Recognize the commonly found Internet file types.

Understand how browsers launch different plug-ins and helper applications to play certain types of files.

Explain why MIDI files occupy so much less file space than waveform audio files.

Understand the concept of a markup language.

Know the difference between the GIF and JPEG graphics formats.

Understand why the audio/video interleave (AVI) file format was designed to give audio the priority when a computer does not have enough processing time to show all of the frames of a movie.

Explain the difference between lossy and lossless compression methods.

Understand how animated GIFs can bring a Web page to life.

Explain the concept of a JavaScript.

Understand the purpose of Adobe's Portable Document Format.

Know the rule search engines use to decide whether to include or exclude active server pages (ASP) files from a search.

Avoid the common pitfall of changing a filename extension when you rename a file.

INTERNET LITERACY RESOURCES:

Text Formats
 

Find an example of each of these formats. How does an ascii text file appear different from an html file? What do you notice about the image you are able to view and the tools that Adobe provides?


Definition from WhatIs?.com

 

 

W3C's home page for HTML

Copyright © W3C® 1994-2002 (MIT, NRIA, Keio). All Rights Reserved.

 

 

Adobe PDF



Image Formats
 

Find a sample of each of the image file formats: gif, jpeg and png. Do you notice any difference in the images?


GIF Info Page

 

 

JPEG

Joint Photographic Experts Group (JPEG) Home Page 

 

 

PNG at W3C

Copyright © W3C® 1994-2002 (MIT, NRIA, Keio). All Rights Reserved.


Waveform Audio Formats
 

Follow the links below to try out the different audio formats. Which ones played right away on your computer? Did you have to add any software to get others to play?


A good technical overview of the various types of sound files can be found at the SoundApp (Mac) homepage.

 

 

Whatis?com's definition of Wave Files

AudioArchive

 

 
RealVideo

RealAudio

 

 

Webopedia definition of AIFF

 

 

Definitions from DVD-Tool.com

 

 

Definition from DigitalPresentation.gov

^Top

MP3
 

Follow the links to sample an MP3 file. How did it compare to MIDI and to the other formats? What information can an MP3 file hold that the others cannot?




 

 

MP3.com
MPEG.ORG


MIDI Synthesizer Format (MIDI)
 

MIDI files provide a much different musical experience from the ones you've just tried. How did they differ?




 

 

MIDIWorld

Video Formats
 

For video, you'll need to add some software to your computer to view the files if you haven't done so already. Follow each of the links below to test your computer for each kind of video format. If you need to, download and install the correct software to view the sample files.




 

 

Apple QuickTime site

 

 

 

Definition from DigitalPresentation.gov

 

 

MPEG
Motion Pictures Experts Group

 

 

RealVideo

RealVideo®


RFC 2326 - Real Time Streaming Protocol (RTSP)


Animation Formats
 

Some animation formats should play immediately in your browser; others will need added software. Which of these formats required you to download additional software? Were you able to view examples of each type of animation?




Optimizing Animated GIFs
The Animation Patch

 

 

JavaScript Kit

 

 


Apple QuickTime site


 

 

 
Shockwave



Active Server Pages (ASP)
 

Have you noticed any difference between .asp pages and .html pages? Why do you think that is?

ASP.net




Exercises
 



Compare classic.mid (17KB) to snippet.wav (17KB).



Case
 

Use these links to find files to test on your target computer as you work through this case.

JPEG image
Animated GIF
PNG image
WAV audio
MIDI song
MP3 song
QuickTime Movie
RealVideo clip
AVI Movie
MPEG movie
(7 MB)
Shockwave animation
Microsoft Word document
Flash
Excel Spreadsheet
Plain text file
PDF File


-

^Top

Home/\

>

Previous Chapter

Summary of this Chapter

Table of Contents

Next Chapter


Book Cover This page is part of the Internet Literacy Web site.
FIND OUT MORE
about Internet Literacy, the new book by Fred T. Hofstetter
published by Irwin/McGraw-Hill

Copyright © 2005 by the University of Delaware. All rights reserved.
Site design and development by Pat Sine.
Please send all comments to Pat Sine: sine@udel.edu