Learning Flash Media Server 3

Chapter 10. Bringing in Data and Working with Configuration Files

Cue Points, Metadata, and Stream Completion

Certain kinds of data are built into FLV files for use by developers. This book features many examples of metadata, either in use or handled to avoid errors. One description of metadata is definitional data that provides information about, or documentation of, other data managed within an application or environment. Examples of metadata in this book illustrate that something is going on with FLV files that requires coding to handle the metadata. The metadata arising from a FLV file is delivered through a net stream. Using the NetStream.client property with ActionScript 3.0, you can create an object and assign it to NetStream.client. Then using that object, you can use the NetStream event handlers to pull out cue point and metadata information. Use that information for controls or additional information. For example, if you are setting up a presentation application, you can use cue points to send text to an output window to emphasize content in the video. Likewise, you can use the duration property of metadata for scaling a slider or any other use. Of course, you can use the object to trigger functions related to other NetStream events. For instance, the NetStream.onPlayStatus is sent even when a stream has been completely played. Here is some of the information contained within cue points and metadata:

Cue Point Properties

• Name

• Parameters

• Time

• Type

Typical Metadata Properties