class flash.media.Sound extends EventDispatcher

Available on all platforms

The Sound class lets you work with sound in an application. The Sound class * lets you create a Sound object, load and play an external MP3 file into * that object, close the sound stream, and access data about the sound, such * as information about the number of bytes in the stream and ID3 metadata. * More detailed control of the sound is performed through the sound source * - the SoundChannel or Microphone object for the sound - and through the * properties in the SoundTransform class that control the output of the sound * to the computer's speakers. *

In Flash Player 10 and later and AIR 1.5 and later, you can also use * this class to work with sound that is generated dynamically. In this case, * the Sound object uses the function you assign to a sampleData * event handler to poll for sound data. The sound is played as it is * retrieved from a ByteArray object that you populate with sound data. You * can use Sound.extract() to extract sound data from a Sound * object, after which you can manipulate it before writing it back to the * stream for playback.

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To control sounds that are embedded in a SWF file, use the properties in * the SoundMixer class.

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Note: The ActionScript 3.0 Sound API differs from ActionScript * 2.0. In ActionScript 3.0, you cannot take sound objects and arrange them in * a hierarchy to control their properties.

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When you use this class, consider the following security model:

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  • Loading and playing a sound is not allowed if the calling file is in * a network sandbox and the sound file to be loaded is local.
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  • By default, loading and playing a sound is not allowed if the calling * file is local and tries to load and play a remote sound. A user must grant * explicit permission to allow this type of access.
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  • Certain operations dealing with sound are restricted. The data in a * loaded sound cannot be accessed by a file in a different domain unless you * implement a cross-domain policy file. Sound-related APIs that fall under * this restriction are Sound.id3, * SoundMixer.computeSpectrum(), * SoundMixer.bufferTime, and the SoundTransform * class.
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However, in Adobe AIR, content in the application security * sandbox(content installed with the AIR application) are not restricted by * these security limitations.

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For more information related to security, see the Flash Player Developer * Center Topic: <a href="http://www.adobe.com/go/devnetsecurityen" * scope="external">Security.

* * @event complete Dispatched when data has loaded successfully. * @event id3 Dispatched by a Sound object when ID3 data is available * for an MP3 sound. * @event ioError Dispatched when an input/output error occurs that causes * a load operation to fail. * @event open Dispatched when a load operation starts. * @event progress Dispatched when data is received as a load operation * progresses. * @event sampleData Dispatched when the runtime requests new audio data.

Instance Fields

var bytesLoaded:UInt

Returns the currently available number of bytes in this sound object. This * property is usually useful only for externally loaded files.

var bytesTotal:Int

Returns the total number of bytes in this sound object.

var id3:ID3Info

Provides access to the metadata that is part of an MP3 file. *

MP3 sound files can contain ID3 tags, which provide metadata about the * file. If an MP3 sound that you load using the Sound.load() * method contains ID3 tags, you can query these properties. Only ID3 tags * that use the UTF-8 character set are supported.

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Flash Player 9 and later and AIR support ID3 2.0 tags, specifically 2.3 * and 2.4. The following tables list the standard ID3 2.0 tags and the type * of content the tags represent. The Sound.id3 property * provides access to these tags through the format * mysound.id3.COMM, mysound.id3.TIME, and so on. * The first table describes tags that can be accessed either through the ID3 * 2.0 property name or the ActionScript property name. The second table * describes ID3 tags that are supported but do not have predefined * properties in ActionScript.

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When using this property, consider the Flash Player security model:

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  • The id3 property of a Sound object is always permitted * for SWF files that are in the same security sandbox as the sound file. For * files in other sandboxes, there are security checks.
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  • When you load the sound, using the load() method of the * Sound class, you can specify a context parameter, which is a * SoundLoaderContext object. If you set the checkPolicyFile * property of the SoundLoaderContext object to true, Flash * Player checks for a URL policy file on the server from which the sound is * loaded. If a policy file exists and permits access from the domain of the * loading SWF file, then the file is allowed to access the id3 * property of the Sound object; otherwise it is not.
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However, in Adobe AIR, content in the application security * sandbox(content installed with the AIR application) are not restricted by * these security limitations.

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For more information related to security, see the Flash Player * Developer Center Topic: <a * href="http://www.adobe.com/go/devnetsecurityen" * scope="external">Security.

var isBuffering:Bool

Returns the buffering state of external MP3 files. If the value is * true, any playback is currently suspended while the object * waits for more data.

var isURLInaccessible:Bool

Indicates if the Sound.url property has been truncated. When * the isURLInaccessible value is true the * Sound.url value is only the domain of the final URL from * which the sound loaded. For example, the property is truncated if the * sound is loaded from http://www.adobe.com/assets/hello.mp3, * and the Sound.url property has the value * http://www.adobe.com. The isURLInaccessible * value is true only when all of the following are also true: *

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  • An HTTP redirect occurred while loading the sound file.
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  • The SWF file calling Sound.load() is from a different * domain than the sound file's final URL.
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  • The SWF file calling Sound.load() does not have * permission to access the sound file. Permission is granted to access the * sound file the same way permission is granted for the * Sound.id3 property: establish a policy file and use the * SoundLoaderContext.checkPolicyFile property.
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Note: The isURLInaccessible property was added for * Flash Player 10.1 and AIR 2.0. However, this property is made available to * SWF files of all versions when the Flash runtime supports it. So, using * some authoring tools in "strict mode" causes a compilation error. To work * around the error use the indirect syntax * mySound["isURLInaccessible"], or disable strict mode. If you * are using Flash Professional CS5 or Flex SDK 4.1, you can use and compile * this API for runtimes released before Flash Player 10.1 and AIR 2.

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For application content in AIR, the value of this property is always * false.

var length:Float

The length of the current sound in milliseconds.

var url:String

The URL from which this sound was loaded. This property is applicable only * to Sound objects that were loaded using the Sound.load() * method. For Sound objects that are associated with a sound asset from a * SWF file's library, the value of the url property is * null. *

When you first call Sound.load(), the url * property initially has a value of null, because the final URL * is not yet known. The url property will have a non-null value * as soon as an open event is dispatched from the Sound * object.

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The url property contains the final, absolute URL from * which a sound was loaded. The value of url is usually the * same as the value passed to the stream parameter of * Sound.load(). However, if you passed a relative URL to * Sound.load() the value of the url property * represents the absolute URL. Additionally, if the original URL request is * redirected by an HTTP server, the value of the url property * reflects the final URL from which the sound file was actually downloaded. * This reporting of an absolute, final URL is equivalent to the behavior of * LoaderInfo.url.

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In some cases, the value of the url property is truncated; * see the isURLInaccessible property for details.

function new(?stream:URLRequest, ?context:SoundLoaderContext):Void

Creates a new Sound object. If you pass a valid URLRequest object to the * Sound constructor, the constructor automatically calls the * load() function for the Sound object. If you do not pass a * valid URLRequest object to the Sound constructor, you must call the * load() function for the Sound object yourself, or the stream * will not load. * *

Once load() is called on a Sound object, you can't later * load a different sound file into that Sound object. To load a different * sound file, create a new Sound object.

* In Flash Player 10 and later and AIR 1.5 and later, instead of using * load(), you can use the sampleData event handler * to load sound dynamically into the Sound object. * *

stream

The URL that points to an external MP3 file. *

context

An optional SoundLoader context object, which can define the buffer time(the minimum number of milliseconds of MP3 data to hold in the Sound object's buffer) and can specify whether the application should check for a cross-domain policy file prior to loading the sound.

function close():Void

Closes the stream, causing any download of data to cease. No data may be * read from the stream after the close() method is called. * *

function extract(target:ByteArray, length:Float, ?startPosition:Float):Float

Extracts raw sound data from a Sound object. *

This method is designed to be used when you are working with * dynamically generated audio, using a function you assign to the * sampleData event for a different Sound object. That is, you * can use this method to extract sound data from a Sound object. Then you * can write the data to the byte array that another Sound object is using to * stream dynamic audio.

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The audio data is placed in the target byte array starting from the * current position of the byte array. The audio data is always exposed as * 44100 Hz Stereo. The sample type is a 32-bit floating-point value, which * can be converted to a Number using ByteArray.readFloat(). *

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target

A ByteArray object in which the extracted sound samples are placed.

length

The number of sound samples to extract. A sample contains both the left and right channels - that is, two 32-bit floating-point values. *

returns

The number of samples written to the ByteArray specified in the * target parameter.

function load(stream:URLRequest, ?context:SoundLoaderContext):Void

Initiates loading of an external MP3 file from the specified URL. If you * provide a valid URLRequest object to the Sound constructor, the * constructor calls Sound.load() for you. You only need to call * Sound.load() yourself if you don't pass a valid URLRequest * object to the Sound constructor or you pass a null value. *

Once load() is called on a Sound object, you can't later * load a different sound file into that Sound object. To load a different * sound file, create a new Sound object.

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When using this method, consider the following security model:

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  • Calling Sound.load() is not allowed if the calling file * is in the local-with-file-system sandbox and the sound is in a network * sandbox.
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  • Access from the local-trusted or local-with-networking sandbox * requires permission from a website through a URL policy file.
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  • You cannot connect to commonly reserved ports. For a complete list * of blocked ports, see "Restricting Networking APIs" in the ActionScript * 3.0 Developer's Guide.
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  • You can prevent a SWF file from using this method by setting the * allowNetworking parameter of the object and * embed tags in the HTML page that contains the SWF * content.
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In Flash Player 10 and later, if you use a multipart Content-Type(for * example "multipart/form-data") that contains an upload(indicated by a * "filename" parameter in a "content-disposition" header within the POST * body), the POST operation is subject to the security rules applied to * uploads:

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  • The POST operation must be performed in response to a user-initiated * action, such as a mouse click or key press.
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  • If the POST operation is cross-domain(the POST target is not on the * same server as the SWF file that is sending the POST request), the target * server must provide a URL policy file that permits cross-domain * access.
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Also, for any multipart Content-Type, the syntax must be valid * (according to the RFC2046 standards). If the syntax appears to be invalid, * the POST operation is subject to the security rules applied to * uploads.

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In Adobe AIR, content in the application security sandbox * (content installed with the AIR application) are not restricted by these * security limitations.

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For more information related to security, see the Flash Player * Developer Center Topic: <a * href="http://www.adobe.com/go/devnetsecurityen" * scope="external">Security.

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stream

A URL that points to an external MP3 file. *

context

An optional SoundLoader context object, which can define the buffer time(the minimum number of milliseconds of MP3 data to hold in the Sound object's buffer) and can specify whether the application should check for a cross-domain policy file prior to loading the sound. *

function loadCompressedDataFromByteArray(bytes:ByteArray, bytesLength:UInt):Void

function loadPCMFromByteArray(bytes:ByteArray, samples:UInt, ?format:String, ?stereo:Bool, ?sampleRate:Float):Void

function play(?startTime:Float, ?loops:Int, ?sndTransform:SoundTransform):SoundChannel

Generates a new SoundChannel object to play back the sound. This method * returns a SoundChannel object, which you access to stop the sound and to * monitor volume.(To control the volume, panning, and balance, access the * SoundTransform object assigned to the sound channel.) * *

startTime

The initial position in milliseconds at which playback * should start. *

loops

Defines the number of times a sound loops back to the * startTime value before the sound channel * stops playback. *

sndTransform

The initial SoundTransform object assigned to the sound channel.

returns

A SoundChannel object, which you use to control the sound. This method returns null if you have no sound card or if you run out of available sound channels. The maximum number of * sound channels available at once is 32.