Excerpt of XHTML Example by Example by Aaron E. Walsh and Dave Raggett
Synchronized Multimedia Integration Layer (SMIL), pronounced “smile", is a graphics language based on the Extensible Markup Language (XML) that enables TV-like multimedia presentations. SMIL is an XML language that content authors can use to create TV-like multimedia presentations for the Web that will be played on browser plug-ins such as Real's RealOne player. According to the World Wide Web Consortium (W3C), the organization responsible for developing it, SMIL is a “language for choreographing multimedia presentations where audio, video, text and graphics are combined in real-time. Simply put, it enables authors to specify what should be presented when, enabling them to control the precise time that a sentence is spoken and make it coincide with the display of a given image appearing on the screen.”
In other words, SMIL enables a wide range of multimedia
applications. After considering what’s possible with SMIL you’ll soon find
that its potential is practically unlimited. SMIL can be used to create simple
multimedia sideshows in addition to sophisticated rich media Web applications
such as interactive video, video on demand (VoD), distance learning, corporate
meetings, and more. Because SMIL allows us to coordinate and present multimedia
based on the passing of time and user interaction, the sky’s the limit if you
take advantage of these features creatively.
...
Because SMIL is an XML language you can create relatively simple presentations
using nothing more than a text editor. As with SVG, however, you’ll get the
biggest bang for your buck using a SMIL authoring tool. This is especially true
when the tool is free.
Before you begin creating any SMIL presentation that involves audio or video you must first consider the streaming media format to use for your project. Most professional-level SMIL authoring tools— Real's products included—will actually convert non-streaming audio and video files into an appropriate streaming format.
Typically, the streaming format the authoring tool uses is based on the tool itself. Real's products will convert your audio and video files into the RealAudio and RealVideo streaming format, for example. SMIL authoring tools for Apple QuickTime, on the other hand, typically convert non-streaming media into the QuickTime format. An emerging class of authoring tools that stand independent of a specific format will let you specify the streaming media format of your choice, which is an added measure of flexibility that many professional Web developers require.
Unfortunately, today’s dominant streaming media formats aren’t interoperable. Real, QuickTime, and Microsoft Media are not compatible with each other, nor are they compatible with other less popular streaming formats. Because most streaming media formats are proprietary, the SMIL authoring tool that you use will most likely determine the SMIL player that end users will need to view your final product.
Because most streaming media files can only be streamed from a server configured for that format you must also consider the server that will ultimately host your SMIL presentation. If you don’t have access to a server that supports Real streaming media formats, for instance, users won’t be able to experience your presentation. The same goes for other streaming formats. If your SMIL presentation contains streaming media it should be hosted on a server that actually supports that format...
Excerpt of XHTML Example by Example by Aaron E. Walsh and Dave Raggett