FLV Output
The FLV file format, which has been supported since Flash version 7, is the preferred file format for delivering video clips via Flash. FLV files cannot be played back directly; they must be embedded in (or linked from) an SWF file. You create (or download) a "container" SWF file from which to play the FLV file. The most common approach is to use an SWF file that functions as a media player with screen and playback controls (see Figure 2).
Figure 2 Flash FLV file embedded into a container SWF file with a playback control "skin"