If you read my previous article on implementing Flash in QuickTime, you discovered the power that comes with merging the two technologies together. Flash offers a convenient environment for authoring interactivity in the QuickTime format.

Flash is everywhere these days so it is probably not a big surprise to find out that bringing Flash into QuickTime is not the only power combo in town. Indeed, RealNetworks offers its own take on the solution with RealFlash (now known by RealNetworks more formally as RealG2 with Flash)

RealFlash has actually been around for quite a while (in Internet terms). Rolled out several years ago as the result of a partnership between Macromedia and RealNetworks, RealFlash was available even before RealNetworks shipped the RealPlayer G2 with SMIL support. Now that SMIL is a common part of authoring content for the RealSystem, RealFlash offers even more opportunities for the streaming multimedia author.

The initial philosophy behind RealFlash was to use strengths of each platform. Flash covers the visual side with its animation. RealAudio is brought in to handle the audio component. It is a good partnership, even if a bit awkward to author for. But stay tuned for future developments. The RealSystem of today offers a RealFlash 4 plug-in for the RealPlayer that supports more of the Flash environment than ever before. With each new version, you can expect see even more functionality and a tighter integration.

Building the Flash Content
Of course, before you can have RealFlash content, you must have Flash content to start with. If you are new to RealFlash, my first bit of advice is to keep it simple. As with the Flash integration you would find in other streaming architectures, what works in Flash may not necessarily work the same in RealFlash. In fact, until just recently, RealFlash was limited to Flash 2 capabilities. RealNetworks encouraged streaming authors to keep their presentations linear. Now with RealNetworks' latest work with Macromedia, RealFlash now supports all Flash 3 and 4 commands.

Indeed, that is what I found. In testing a simple but recent sample built for Flash 4 output, I found the interactive content ran in a newer RealPlayer without a glitch. True, RealPlayer did have to auto-update to a newer RealFlash plug-in before being able to run the movie. But this very non-linear presentation performed as expected. Currently, the biggest limitation of working with RealFlash is in handling the audio. As mentioned earlier, RealNetworks and Macromedia have developed an environment that plays to the strengths of each format. So that means the "Real" component of RealFlash focuses on the streaming audio while the "Flash" component focuses on the animation. While Real and Macromedia may offer a cleaner solution in the future, what that currently means is manually splitting your audio apart from the Flash presentation and finding a way to synchronize it back up again. For a linear presentation with streaming sound, this is a relatively simple task with SMIL. Just break the visual from the audio and use SMIL to stitch them back together in their respective formats. But RealPlayer is not going to cleanly support event sounds tied to interactivity. If you are building an interactive presentation with event sounds, expect numerous obstacles to overcome. It is currently more practical to simplify your presentation than to find SMIL-based workarounds.