Does Dynamic Streaming require ActionScript, or is it a function of the server?
The stream transitions occur on the server, but the command to switch streams and the determination to do so come from ActionScript commands in the client SWF application. The Flash and Adobe Flex® ActionScript developer includes logic in the application to monitor download and playback statistics and to switch from the old stream to the new stream when appropriate. Adobe is providing a full ActionScript 3.0 class that developers can use to easily make use of Dynamic Streaming. A sample video player and updated FLVPlayback component for Flash CS4 Professional can be downloaded from the tools page (coming soon).