Package | flash.events |
Class | public class SampleDataEvent |
Inheritance | SampleDataEvent Event Object |
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
This event has two uses:
- To provide dynamically generated audio data for a Sound object
- To get audio data for a Microphone object
Dynamically generating audio using the Sound object Use the
sampleData
event to play dynamically generated audio. In this environment,
the Sound object doesn't actually contain sound data. Instead, it acts as a socket for
sound data that is being streamed to it through the use of the function
you assign as the handler for the sampleData
event.
In your function, you use the ByteArray.writeFloat()
method to write to
the event's data
) property, which contains the sampled data you
want to play.
If a Sound object has not loaded an MP3 file, when you call its play()
method
the object starts dispatching sampleData
events, requesting sound samples.
The Sound object continues to send events as the sound plays back until you stop providing data,
or until the stop()
method of the SoundChannel object is called.
Thes latency of the event varies from platform to platform, and it could change in future
versions of Flash Player or AIR. Don't depend on a specific latency.
Instead calculate it using ((SampleDataEvent.position/44.1) - SoundChannelObject.position)
.
Provide between 2048 and 8192 samples to the data
property of
the SampleDataEvent object. For best performance, provide as many samples as possible.
The fewer samples you provide, the more likely it is
that clicks and pops will occur during playback. This behavior can differ on various platforms
and can occur in various situations - for example, when resizing the browser.
You might write code that works on one platform when you provide only 2048 samples, but that same code
might not work as well when run on a different platform. If you require the lowest latency possible,
consider making the amount of data user-selectable.
If you provide fewer than 2048 samples, tha Sound object plays the remaining samples
and then stops the sound as if the end of a sound file was reached, generating
a complete
event.
You can use the extract()
method of a Sound object to extract its sound data,
which you can then write to the dynamic stream for playback.
When you use the sampleData
event with a Sound object, the only Sound methods that
are enabled are extract()
and play()
. Calling any other methods or properties
results in an "invalid call" exception. All methods and properties of the SoundChannel object
are still enabled.
Capturing Microphone audio Use the sampleData
event
to capture audio data from a microphone. When you add an event listener for the
sampleData
event, the Microphone dispatches the event as audio samples
become available.
In the event handler function, use the ByteArray.readFloat()
method to read
the event's data
) property, which contains the sampled data. The event will contain
multiple samples, so you should use a while
loop to read the available data:
var soundBytes:ByteArray = new ByteArray(); while(event.data.bytesAvailable) { var sample:Number = event.data.readFloat(); soundBytes.writeFloat(sample); }
Learn more
Related API Elements
Property | Defined By | ||
---|---|---|---|
bubbles : Boolean [read-only]
Indicates whether an event is a bubbling event. | Event | ||
cancelable : Boolean [read-only]
Indicates whether the behavior associated with the event can be prevented. | Event | ||
constructor : Object
A reference to the class object or constructor function for a given object instance. | Object | ||
currentTarget : Object [read-only]
The object that is actively processing the Event object with an event listener. | Event | ||
data : ByteArray
The data in the audio stream. | SampleDataEvent | ||
eventPhase : uint [read-only]
The current phase in the event flow. | Event | ||
position : Number
The position of the data in the audio stream. | SampleDataEvent | ||
target : Object [read-only]
The event target. | Event | ||
type : String [read-only]
The type of event. | Event |
Method | Defined By | ||
---|---|---|---|
SampleDataEvent(type:String, bubbles:Boolean = false, cancelable:Boolean = false, theposition:Number = 0, thedata:ByteArray = null)
Creates an event object that contains information about audio data events. | SampleDataEvent | ||
[override]
Creates a copy of the SampleDataEvent object and sets each property's value to match that of the original. | SampleDataEvent | ||
A utility function for implementing the toString() method in custom
ActionScript 3.0 Event classes. | Event | ||
Indicates whether an object has a specified property defined. | Object | ||
Checks whether the preventDefault() method has been called on the event. | Event | ||
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | ||
Cancels an event's default behavior if that behavior can be canceled. | Event | ||
Indicates whether the specified property exists and is enumerable. | Object | ||
Sets the availability of a dynamic property for loop operations. | Object | ||
Prevents processing of any event listeners in the current node and any subsequent nodes in
the event flow. | Event | ||
Prevents processing of any event listeners in nodes subsequent to the current node in the
event flow. | Event | ||
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | ||
[override]
Returns a string that contains all the properties of the SampleDataEvent object. | SampleDataEvent | ||
Returns the primitive value of the specified object. | Object |
Constant | Defined By | ||
---|---|---|---|
SAMPLE_DATA : String = "sampleData" [static]
Defines the value of the type property of a SampleDataEvent event object. | SampleDataEvent |
data | property |
position | property |
SampleDataEvent | () | Constructor |
public function SampleDataEvent(type:String, bubbles:Boolean = false, cancelable:Boolean = false, theposition:Number = 0, thedata:ByteArray = null)
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Creates an event object that contains information about audio data events. Event objects are passed as parameters to event listeners.
Parameterstype:String — The type of the event. This value is:Event.SAMPLE_DATA .
| |
bubbles:Boolean (default = false ) — Determines whether the Event object participates in the bubbling stage of the event flow.
| |
cancelable:Boolean (default = false ) — Determines whether the Event object can be canceled.
| |
theposition:Number (default = 0 ) — The position of the data in the audio stream.
| |
thedata:ByteArray (default = null ) — A byte array of data.
|
clone | () | method |
override public function clone():Event
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Creates a copy of the SampleDataEvent object and sets each property's value to match that of the original.
ReturnsEvent — A new SampleDataEvent object with property values that match those of the original.
|
toString | () | method |
override public function toString():String
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Returns a string that contains all the properties of the SampleDataEvent object. The string is in the following format:
[SampleDataEvent type=value bubbles=value cancelable=value theposition=value thedata=value]
String — A string that contains all the properties of the SampleDataEvent object.
|
SAMPLE_DATA | Constant |
public static const SAMPLE_DATA:String = "sampleData"
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Defines the value of the type
property of a SampleDataEvent
event object.
This event has the following properties:
Property | Value |
---|---|
bubbles | false |
cancelable | false ; there is no default behavior to cancel. |
position | The point from which audio data is provided. |
Related API Elements
var mySound:Sound = new Sound(); function sineWaveGenerator(event:SampleDataEvent):void { for ( var c:int=0; c<8192; c++ ) { event.data.writeFloat(Math.sin((Number(c+event.position)/Math.PI/2))*0.25); event.data.writeFloat(Math.sin((Number(c+event.position)/Math.PI/2))*0.25); } } mySound.addEventListener(SampleDataEvent.SAMPLE_DATA,sineWaveGenerator); mySound.play();
Wed Nov 21 2018, 06:34 AM -08:00