Hands-On Guide to Flash Video

CHAPTER 8

Producing Alpha Channel Video

Flash 8 introduced the ability to utilize FLV files with an alpha channel in Flash projects and key out the background in real time during playback. The only caveat (as detailed in Chapter 15) is that real-time keying is processor intensive on the viewing station, which can slow playback on lower-end computers.

To successfully create real-world (as opposed to animated) video with an alpha channel, you’ll have to shoot against a blue or green screen. I won’t describe that process in this book, though I touch on lighting for such video in Chapter 4. Instead, I’ll focus on the workflow for creating FLV files with an alpha channel, which has two stages:

•  Using a chroma key or similar effect in an editor ...