Time for a Timeline

Now this is all very fine, but we're still talking about either downloading a file in the old tried-and-true way, or delivering an audio (or video) file by itself over the Internet. If the Internet is to support true sequential delivery of multimedia, like TV, then we need a standard that lets us deliver various types of audio, graphic, text and video formats in a sequential way - that is, locked to a timeline. We need to be able to say, "this event happens at exactly this time, and that event happens at exactly that time, in relation to the other events." This cannot be done with HTML alone.

It can, of course, be done with any of the various multimedia authoring tools, of which Macromedia's Director is perhaps the best known. Working with the Internet is often like reinventing the wheel - all we're trying to do here is take something that we've been able to do on a desktop computer for years, and do it over the Internet, meaning in a way that is platform-independent. Now that the bandwidth is becoming available, a host of competing standards (naturally) have cropped up.

The aforementioned Macromedia has been offering tools for Web multimedia delivery for years - Shockwave and Flash. Although these are powerful tools, they are proprietary software packages, complete with authoring tools and a browser plug-in for playback, and they're limited in their abilities to incorporate different types of media. What we really crave is an open, evolving standard for time-based multimedia delivery - something like HTML with a sense of timing - which can incorporate any and all media formats, including Shockwave or Flash.

This is just what the Synchronized Multimedia Integration Language (SMIL) was designed to be. The W3C (World Wide Web Consortium) introduced SMIL in mid-1998 as a standard language for sequential Web multimedia. SMIL is based on SGML, and has similarities to XML. It allows audio, video, still images, text, and even animations (including Flash) to be assembled into complete presentations, with precise control over the time and position of each element. With early support from most of the major players in the Internet multimedia world, it looked as if a new day of open standards-based Web multimedia had dawned.

Then, of course, the predictable happened. Microsoft and Macromedia left the SMIL tent and proposed their own competing standard, HTML+TIME. RealNetworks, however, embraced SMIL, and it remains the backbone of their industry-standard G2 media player. Microsoft upgraded the streaming capabilities of their Windows Media Player (long scoffed at by audio weenies), and began presenting it as a direct competitor to RealNetworks' product. And lo, yet another format war was kindled.

And then there's QuickTime. Owned by Apple, QuickTime started out as the native Mac video format, and has evolved into a sophisticated streaming multimedia platform. Most windows platforms support QuickTime, so there's no longer anything Mac-only about it. Unlike some of Apple's other ventures, QuickTime has not only steadily improved over the years, but has also been decently marketed, so that it's fairly well known. QuickTime is in fact Viable Contender Number 3 in the Web multimedia arena, together with RealNetworks and Microsoft.

Recently, Microsoft has rejoined the SMIL standards process, although they continue to tout their HTML+TIME (currently supported only by IE 5). And the current version of QuickTime now supports SMIL. So it may be that the standards will eventually converge, or at least that the struggle will be concealed from the end user. But for now, there are three main standards for Web-based sequential multimedia. As usual, the weary developer must be prepared to produce output in all three formats.

Audio Formats for the Web
Web Audio 2000
Authoring Tools