(Shelly Cashman Series) Gary B. Shelly, H. Albert Napier, Ollie N. Rivers-Web design_ introductory concepts and techniques -Cengage Learning (2008)

Interactive Elements 171
EDITING VIDEO FILES You can manipulate certain aspects of video — frame size,
frame rate, bit depth, compression scheme, and overall video quality — to optimize Web
videos. Although you might never edit video yourself, understanding these aspects can
help you make informed choices about including video at your Web site. You learned
about the concept of frames in the previous sections on animation and Flash movies. For
Web-based videos, consider the following:
• The common frame sizes are 160 120 or 240 180 pixels; the frame rate for
Web video ranges from 10 to 15 frames per second (fps).
• As with audio, the greater the number of bits or bit depth, the bigger the file size. If
you decrease a video segment from 16-bit to 8-bit, the file size will decrease significantly,
as will the quality. Experiment with different settings to find a balance that is
acceptable.
• You can define the general quality level of your video, which automatically adjusts
the compression. If you define the quality between low and medium, you will
achieve a good balance between sufficient compression and video quality that is
suitable for the Web.
Interactive Elements
In Chapter 2, you learned that a well-designed Web site should include elements that
enable the site publisher and site visitors to engage in interactive, two-way communication.
You also learned about a variety of interactive elements that can be used to promote
interactivity, such as contact pages and Web-based forms.
Web-based forms allow visitors to submit information to a site publisher using e-mail
or directly to a database. Scripting languages, applets, and servlets play a role in creating
interactive elements, such as rollover buttons or games, for Web pages. Blogging is a
powerful tool to promote interactivity; you can easily host a blog at your site using open
source freeware. Many e-commerce sites encourage communication and promote
interactivity by using live chat.
Web-based Form Guidelines
In Chapter 2, you were introduced to Web-based forms, which are structured Web
documents on which information can be entered or options selected. As you also learned
in Chapter 2, common form elements include text boxes, check boxes, option buttons,
drop-down list boxes, and a Send or Submit button. Forms are frequently used to obtain
comments and feedback or to order products or services.
Multiple form pages to be completed in sequence are necessary when a single form is
not adequate to gather all the necessary information. An example of multiple, sequential
form pages is an e-commerce site shopping cart. A series of shopping cart form pages
allows an online shopper to review purchases, enter shipping information (name, address,
and phone number), enter billing information (credit card number, holder’s name and
address, and an authorization code, if necessary), and, finally, verify entered information
and submit the form.
Q&A
@SOURCE
What is a screencast?
A screencast is a video
of a computer screen’s
changing content over
time and is used for
Web-based training
videos and demonstrations.
Software such as
Camtasia Studio is used
to create a screencast.
Optimizing Video
For more information
about how you can optimize
video files, visit the
Web Design Chapter 6
Online Companion page
(scsite.com/web3e/ch6/)
and then click Optimizing
Video in the @Source links.