One of the biggest factors in the growth of the web has been the
integration of multimedia capabilities within HTML documents. Since the
early versions of HTML, it has been possible to include references to images
in a document that would allow the embedding of the image in-line along with
document text content. Later, HTML was extended to allow the embedding of
not just static images, but sound, video, and VRML files as well. All of
these capabilities now allow for a very rich web surfing experience.
Ensuring Your Content is Conveyed as Intended
To be sure, not all browsers for HTML can support multimedia. Nor can
every reader experience all the features that multimedia can provide. This
fact must also always be considered in HTML design. As the quantities and
types of multimedia capability have grown in HTML, it has become ever more
difficult to prevent the persistent slide of content on the web to being
primarily multimedia based. Not to say this is a bad thing, but not
EVERYONE can experience these capabilities. The reader may have a
physical disability that may prevent the full effect from being experienced or
the user may only have access to a text-based browser. Authors must always
remember that not ALL browsers or readers have the capability to
experience the full intended multimedia experience that they try to deliver.
To this end, there are several methods available to help make multimedia
content degrade well for browsers that can not support it. The IMG element
allows the inclusion of a text string that is only available when an image
can not be loaded (whatever the reason.) The OBJECT element also extends this
a step further by allowing text representations of an Image Map to be
displayed when the Image Map can not be used. These options should
ALWAYS be used to ensure that your content is delivered in
SOME fashion to all readers.
This is the grandpa multimedia element. It was the first element introduced
to allow multimedia capability within documents. It also has the
most extensions of any element (about 20) which allow everything from
the embedding of videos and VRML to a range of border, alignment
and size properties.
This is a method introduced by Spyglass to allow the browser to handle
the transit decisions related to using image maps (hyperlinks defined
by geometric regions of an image.) This process was previously handled
by an external file that contained the geometric hyperlink definitions.
The old method required an extra download request, and possibly
non-trivial access to a web server. This newer method includes the
information inside the HTML page and is generally a faster solution.
These elements are analogous to the BACKGROUND attribute to the
BODY element. They allow the embedding of a
sound that plays while a page is viewed. They are both extensions by
different browser vendors that were created at approximately the same
time. Neither of these elements will ever make it into an HTML standard
now that the OBJECT element can absorb this
functionality.
This is the new element meant to absorb all of the functionality of
the many disparate elements designed to include and process other
multimedia content within an HTML document. This element is meant to absorb and
obsolete the Applet, Area,
BGSound, Embed,
Img, Map, and
Sound elements.