ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with sound
Using the @Embed directive in MXML to assign an embedded asset as a property of a component like a Button or a
SoundEffect.
Using the @Embed directive within a CSS file
This section describes the first option: how to embed sounds in ActionScript code within a Flex application using the
[Embed] metadata tag.
To embed an asset in ActionScript code, use the [Embed] metadata tag.
Place the sound file in the main source folder or another folder that is in your project’s build path. When the compiler
encounters an Embed metadata tag, it creates the embedded asset class for you. You can access the class through a
variable of data type Class that you declare immediately after the [Embed] metadata tag.
The following code embeds a sound named smallSound.mp3 and uses a variable named soundClass to store a
reference to the embedded asset class associated with that sound. The code then creates an instance of the embedded
asset class, casts it as an instance of the Sound class, and calls the play() method on that instance:
package
{
import flash.display.Sprite;
import flash.media.Sound;
import flash.media.SoundChannel;
}
public class EmbeddedSoundExample extends Sprite
{
[Embed(source="smallSound.mp3")]
public var soundClass:Class;
}
public function EmbeddedSoundExample()
{
var smallSound:Sound = new soundClass() as Sound;
smallSound.play();
}
To use the embedded sound to set a property of a Flex component, it should be cast as an instance of the
mx.core.SoundAsset class instead of as an instance of the Sound class. For a similar example that uses the SoundAsset
class see “Embedded asset classes” in Learning ActionScript 3.0.
Working with streaming sound files
Flash Player 9 and later, Adobe AIR 1.0 and later
When a sound file or video file is playing back while its data is still being loaded, it is said to be streaming. External
sound files that are loaded from a remote server are often streamed so that the user doesn’t have to wait for all the
sound data to load before listening to the sound.
The SoundMixer.bufferTime property represents the number of milliseconds of sound data that Flash Player or AIR
should gather before letting the sound play. In other words, if the bufferTime property is set to 5000, Flash Player or
AIR loads at least 5000 milliseconds worth of data from the sound file before the sound begins to play. The default
SoundMixer.bufferTime value is 1000.
Last updated 6/6/2012
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