QuickStudy: Flash

Computerworld -

Listen to Computerworld's TechCast: Flash Animation. Podcast duration: 6 minutes.

When the World Wide Web be-came a mainstream communications medium, people quickly realized that visual appeal was important and, further, that animation attracted a lot more attention than static images. Advertisers especially wanted users to notice their banners and believed that animated graphics gave them an edge. But in the days before broadband access was widely available, animated graphics could mean very long download times.

One of the most significant developments in this area was the rapid proliferation of a graphics approach called Flash. A product of Macromedia Inc. (which Adobe Systems Inc. acquired last month), Flash enabled developers and artists to create sophisticated, frame-by-frame animation that included sound and could be streamed out to a browser. Such "movies" were relatively small and thus would download quickly.

Flash is built around vector graphics (such as PostScript, SVG and PDF files) that, when used with program code, are translated into small file sizes for Flash productions that require less transmission bandwidth than bitmaps or video clips. Besides the vector-rendering engine, the Flash Player includes the ActionScript Virtual Machine for scripting interactivity at runtime, support for video, MP3-based audio and bitmap graphics. The Flash format interleaves media and instructions so graphics start playing more quickly.

Flash players exist for a wide variety of systems and devices, so Flash movies will run consistently on Microsoft Windows, Mac OS 9/X, Linux, and Unix variants such as Solaris, HP-UX, Pocket PC, OS/2, Symbian, Palm OS, BeOS and Irix. An open-source Flash player has been ported to numerous operating systems, including Amiga. Flash Player 8 offers two video coder/decoders and runtime support for several other graphics formats, including JPEG, Progressive JPEG, PNG and GIF.

Going Pro

With its recent 8.0 release, Flash has been split into two products, one of which is a professional edition aimed at developers doing graphics-intensive work. From the beginning, Flash has used a timeline-based approach to defining what happens on-screen and when. Flash Pro 8 adds a forms-based method for creating Flash applications, through which developers can drag and drop items, as they can in many other integrated development environments, including Microsoft Visual Studio .Net and IBM's VisualAge family.