Authoring Tools

So, how do we create these glorious streaming Internet multimedia programs? It depends on which platform(s) you want to author for.

SMIL is a markup language, similar to XML, so SMIL presentations can be created in any text editor, or an HTML editor such as Allaire's HomeSite. In fact, HomeSite offers an optional add-on pack that includes SMIL tags, so this popular Web editor seems a good choice for coding SMIL presentations. There are a few other SMIL authoring tools around - a good list can be found at the W3C. The WDVL section on SMIL includes links to lots of authoring tutorials and tools.

Despite my earlier beating of the war drums about a new standards battle (can't resist), HTML+ TIME (Timed Interactive Multimedia Extensions) is not necessarily a rival to SMIL, but rather an extension of it, which allows SMIL features to be used within HTML, and thus within a standard Web browser. SMIL by itself is designed to be used within a specific client application (Just for an example, take...oh...RealNetworks' G2 Player.) not within a (so-called) browser. HTML+TIME offers the option of including SMIL features within any HTML document. It adds some extensions to deal with timing, synchronization, and interactivity, as well as a Document Object Model (DOM).

Microsoft offers a HTML+TIME authoring tool called Vizact, as part of the Office package. Vizact lets you create HTML+TIME documents (which they call "an Active Document." Hmm - where have we heard that one before?) using a visual timeline and familiar point-and-click editing tools.

Each of the would-be multimedia monsters (RealNetworks, Microsoft, Apple) has their own "native" audio formats, streaming and otherwise, but nowadays there would seem to be little to choose among them, because most audio software can handle all the major formats. That is, The Windows Media Player can handle not only Microsoft's Advanced Streaming Format (.asf), but also RealAudio (.ra), MP3 (.mp3), and just about any other format you're likely to run across. Ditto for RealNetworks and QuickTime. Popular audio editing tools such as Sound Forge, and video editing packages such as Adobe Premiere, can save files in all the main streaming and non-streaming formats, too. "Dedicated" encoders are available for all three streaming formats, and offer geekish features such as letting you choose which compression codec to use, but they aren't strictly necessary.

Nor must a presentation created with any of the three systems use only the file formats associated with that system. For example, a presentation created in SMIL for the RealPlayer can include streaming RealAudio, RealPix and RealText files, but it can also include ASF and QuickTime files, or even files in non-streaming audio formats such as .wav or .aif. On the user's end there are few compatibility problems. It's only the poor developer who must deal with three different ways of putting it all together.

One authoring tool that tries to make things easier is Stream Anywhere, from Sonic Foundry. Stream Anywhere lets you create content for both the Microsoft and RealNetworks platforms in one go. Alas, it doesn't support QuickTime.

QuickTime developers have a variety of authoring tools to choose from, however. Apple's developer site offers plenty of helpful documentation.

A list of streaming media authoring tools for various platforms can be found at Streaming Media World.

Time for a Timeline
Web Audio 2000
Files within Files within Files