Synchronized Multimedia On The Web
A New W3C Format Is All Smiles
By Larry Bouthillier
With the introduction of Synchronized Multimedia Integration Language (SMIL, pronounced smile) earlier this year, Web multimedia creators have a new tool set for building time-based, streaming multimedia presentations that combine audio, video, images, and text. The proposed SMIL standard defines an XML-based language that allows control over the what, where, and when of media elements in a multimedia presentation with a simple, clear markup language similar to HTML.
In a SMIL presentation, all of the media elements -- images, audio clips, video clips, animations, and formatted text -- are referenced from the SMIL file, similar to the way an HTML page references its images, applets, and other elements. A number of advantages come with such an approach to streaming media. First, the plain-text nature of the SMIL file means that it's easy to create, easy to edit, and can even be assembled on-the-fly by Java servlets or CGI scripts accessing a database. It also allows a very bandwidth-friendly way to do great looking multimedia. Rather than streaming images and text as many redundant frames of encoded video, you can stream the image or text data just once, and display it however you like.
The first commercial SMIL player to arrive on the scene is RealNetworks' latest version of RealPlayer, called G2. While the previous versions of RealPlayer played only RealNetworks' proprietary audio and video file formats, G2 includes support for many other media types like WAV, AVI, JPEG, MPEG, and others.
