Video can add considerable size to a Macromedia Flash movie. You should keep in mind your target audience's connection speed when publishing SWFs that contain embedded video. Below are some tips and other items to consider. Also see Tips for creating Flash video with Sorenson Spark in the Importing video section of the Using Flash manual.

Keep video clips short Like all Flash content, video streams into Flash Player. Unlike "true" video streaming, however, a frame of embedded video does not get discarded from memory after being displayed. Very long video clips may eventually affect performance and stability of the playback system. Streaming and file optimization techniques for Flash Player contains general guidelines and techniques for optimizing Flash movies.

Publish one video per SWF The loadMovie action lets you load external Flash movies during playback. You could, for example, publish the same video, with different compression settings (for high, medium, and low bandwidth), in three separate SWFs. You could then let users choose (using the loadMovie action) the appropriate movie for their Internet connection.

Processor speed Flash Player must decompress a frame of video before that frame can be displayed. Lower-end systems may not be able to decompress the video data fast enough to display each frame. If the video clip contains a sound track (or if there's another streaming sound in the SWF), Flash Player will drop frames to keep pace with the sound track. If the video doesn't contain a sound track (or if the file doesn't contain any other streaming sound) then Flash Player won't skip frames.