About playing back external FLV files dynamically

As an alternative to importing video into the Flash authoring environment, you can use ActionScript to dynamically play back external FLV files in Flash Player. You can play back FLV files posted as HTTP downloads or as local media files. To play back FLV files, you use the NetStream object and the attachVideo method of the Video object.

You can create FLV files by importing video into the Flash authoring tool and exporting it as an FLV file. For information on exporting video as an FLV file, see Macromedia Flash Video (FLV). If you have Macromedia Flash MX Professional 2004, you can use the FLV Export plug-in to export FLV files from supported video-editing applications. See Exporting FLV files from video-editing applications (Flash Professional only).

To play back an external FLV file, you must post an FLV file to a URL (either an http site or a local folder) and add ActionScript code to the Flash document to access the file and control playback during runtime.

Using external FLV files provides certain capabilities that are not available when using imported video:

• You can use longer video clips in your Flash documents without slowing down playback. External FLV files are played using cached memory. This means that large files are stored in small pieces and accessed dynamically, and do not require as much memory as embedded video files.
• An external FLV file can have a different frame rate from the Flash document in which it plays. For example, you can set the Flash document frame rate to 30 fps and the video frame rate to 21 fps. This allows you greater control in ensuring smooth video playback.
• With external FLV files, Flash document playback does not have to be interrupted while the video file is loading. Imported video files may sometimes interrupt document playback to perform certain functions for example, to access a CD-ROM drive. FLV files can perform functions independently of the Flash document, and so do not interrupt playback.
• Captioning of video content is easier with external FLV files, because you can use callback functions to access metadata for the video.

For more information on playing back FLV files, see Playing back external FLV files dynamically.