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.

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

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.

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

  • 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.
  • 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.
  • 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.

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

For more information related to security, see the Flash Player Developer Center Topic: 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.

Constructor

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

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.

Parameters:

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.

Variables

read onlybytesLoaded:Int

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

read onlybytesTotal:Int

Returns the total number of bytes in this sound object.

read onlyid3: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.

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 my_sound.id3.COMM, my_sound.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.

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

  • 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.
  • 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.

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

For more information related to security, see the Flash Player Developer Center Topic: Security.

read onlyisBuffering: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.

read onlylength:Float

The length of the current sound in milliseconds.

read onlyurl: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.

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.

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

Methods

close ():Void

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.

When using this method, consider the following security model:

  • 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.
  • Access from the local-trusted or local-with-networking sandbox requires permission from a website through a URL policy file.
  • 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.
  • 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.

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:

  • The POST operation must be performed in response to a user-initiated action, such as a mouse click or key press.
  • 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.

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.

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

For more information related to security, see the Flash Player Developer Center Topic: Security.

Parameters:

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.

Throws:

IOError

A network error caused the load to fail.

IOError

The digest property of the stream object is not null. You should only set the digest property of a URLRequest object when calling the URLLoader.load() method when loading a SWZ file(an Adobe platform component).

SecurityError

Local untrusted files may not communicate with the Internet. You can work around this by reclassifying this file as local-with-networking or trusted.

SecurityError

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.

loadCompressedDataFromByteArray (bytes:ByteArray, bytesLength:Int):Void

loadPCMFromByteArray (bytes:ByteArray, samples:Int, format:String = "float", stereo:Bool = true, sampleRate:Float = 44100):Void

play (startTime:Float = 0.0, loops:Int = 0, ?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.)

Parameters:

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.

Static methods

staticfromAudioBuffer (buffer:AudioBuffer):Sound

staticfromFile (path:String):Sound

staticloadFromFile (path:String):Future<Sound>

staticloadFromFiles (paths:Array<String>):Future<Sound>

Inherited Variables

Inherited Methods

Defined by EventDispatcher

addEventListener (type:String, listener:Dynamic ‑> Void, useCapture:Bool = false, priority:Int = 0, useWeakReference:Bool = false):Void

Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event. You can register event listeners on all nodes in the display list for a specific type of event, phase, and priority.

After you successfully register an event listener, you cannot change its priority through additional calls to addEventListener(). To change a listener's priority, you must first call removeListener(). Then you can register the listener again with the new priority level.

Keep in mind that after the listener is registered, subsequent calls to addEventListener() with a different type or useCapture value result in the creation of a separate listener registration. For example, if you first register a listener with useCapture set to true, it listens only during the capture phase. If you call addEventListener() again using the same listener object, but with useCapture set to false, you have two separate listeners: one that listens during the capture phase and another that listens during the target and bubbling phases.

You cannot register an event listener for only the target phase or the bubbling phase. Those phases are coupled during registration because bubbling applies only to the ancestors of the target node.

If you no longer need an event listener, remove it by calling removeEventListener(), or memory problems could result. Event listeners are not automatically removed from memory because the garbage collector does not remove the listener as long as the dispatching object exists(unless the useWeakReference parameter is set to true).

Copying an EventDispatcher instance does not copy the event listeners attached to it.(If your newly created node needs an event listener, you must attach the listener after creating the node.) However, if you move an EventDispatcher instance, the event listeners attached to it move along with it.

If the event listener is being registered on a node while an event is being processed on this node, the event listener is not triggered during the current phase but can be triggered during a later phase in the event flow, such as the bubbling phase.

If an event listener is removed from a node while an event is being processed on the node, it is still triggered by the current actions. After it is removed, the event listener is never invoked again(unless registered again for future processing).

Parameters:

type

The type of event.

useCapture

Determines whether the listener works in the capture phase or the target and bubbling phases. If useCapture is set to true, the listener processes the event only during the capture phase and not in the target or bubbling phase. If useCapture is false, the listener processes the event only during the target or bubbling phase. To listen for the event in all three phases, call addEventListener twice, once with useCapture set to true, then again with useCapture set to false.

priority

The priority level of the event listener. The priority is designated by a signed 32-bit integer. The higher the number, the higher the priority. All listeners with priority n are processed before listeners of priority n-1. If two or more listeners share the same priority, they are processed in the order in which they were added. The default priority is 0.

useWeakReference

Determines whether the reference to the listener is strong or weak. A strong reference(the default) prevents your listener from being garbage-collected. A weak reference does not.

Class-level member functions are not subject to garbage collection, so you can set useWeakReference to true for class-level member functions without subjecting them to garbage collection. If you set useWeakReference to true for a listener that is a nested inner function, the function will be garbage-collected and no longer persistent. If you create references to the inner function(save it in another variable) then it is not garbage-collected and stays persistent.

Throws:

ArgumentError

The listener specified is not a function.

dispatchEvent (event:Event):Bool

Dispatches an event into the event flow. The event target is the EventDispatcher object upon which the dispatchEvent() method is called.

Parameters:

event

The Event object that is dispatched into the event flow. If the event is being redispatched, a clone of the event is created automatically. After an event is dispatched, its target property cannot be changed, so you must create a new copy of the event for redispatching to work.

Throws:

Error

The event dispatch recursion limit has been reached.

Returns:

A value of true if the event was successfully dispatched. A value of false indicates failure or that preventDefault() was called on the event.

hasEventListener (type:String):Bool

Checks whether the EventDispatcher object has any listeners registered for a specific type of event. This allows you to determine where an EventDispatcher object has altered handling of an event type in the event flow hierarchy. To determine whether a specific event type actually triggers an event listener, use willTrigger().

The difference between hasEventListener() and willTrigger() is that hasEventListener() examines only the object to which it belongs, whereas willTrigger() examines the entire event flow for the event specified by the type parameter.

When hasEventListener() is called from a LoaderInfo object, only the listeners that the caller can access are considered.

Parameters:

type

The type of event.

Returns:

A value of true if a listener of the specified type is registered; false otherwise.

removeEventListener (type:String, listener:Dynamic ‑> Void, useCapture:Bool = false):Void

Removes a listener from the EventDispatcher object. If there is no matching listener registered with the EventDispatcher object, a call to this method has no effect.

Parameters:

type

The type of event.

useCapture

Specifies whether the listener was registered for the capture phase or the target and bubbling phases. If the listener was registered for both the capture phase and the target and bubbling phases, two calls to removeEventListener() are required to remove both, one call with useCapture() set to true, and another call with useCapture() set to false.

toString ():String

willTrigger (type:String):Bool

Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type. This method returns true if an event listener is triggered during any phase of the event flow when an event of the specified type is dispatched to this EventDispatcher object or any of its descendants.

The difference between the hasEventListener() and the willTrigger() methods is that hasEventListener() examines only the object to which it belongs, whereas the willTrigger() method examines the entire event flow for the event specified by the type parameter.

When willTrigger() is called from a LoaderInfo object, only the listeners that the caller can access are considered.

Parameters:

type

The type of event.

Returns:

A value of true if a listener of the specified type will be triggered; false otherwise.