public class AudioReadBuffer extends Transformer
In each iteration, an IntToken is read from the input port, if there is a token available. This token specifies the address of the buffer element to read from. The address is zero-based, so address 0 corresponds to the first element and addres bufferLength -1 corresponds to the last element. The sample value at the specified buffer location is converted to a DoubleToken and sent to the output port.
If an element outside of the valid address range is specified, then a DoubleToken with value 0.0 is output. If the the specified address is greater than bufferLength -1, then this actor will return false in postfire.
This actor does not currently support multichannel sound files, so if a stereo sound file is specified, only the left channel will be used. This limitation may be lifted in a future version of this actor.
The audio samples that are read from the file are converted to DoubleTokens that may range from [-1.0, 1.0]. Thus, the output type of this actor is DoubleToken.
Usage
The sourceURL parameter should be set to the name of the file, specified as a fully qualified URL. It is possible to load a file from the local file system by using the prefix "file://" instead of "http://". Relative file paths are allowed. To specify a file relative to the current directory, use "../" or "./". For example, if the current directory contains a file called "test.wav", then sourceURL should be set to "file:./test.wav". If the parent directory contains a file called "test.wav", then sourceURL should be set to "file:../test.wav". To reference the file test.wav, located at "/tmp/test.wav", sourceURL should be set to "file:///tmp/test.wav" The default value is "file:///tmp/test.wav".
There are security issues involved with accessing files and audio resources in applets. Applets are only allowed access to files specified by a URL and located on the machine from which the applet is loaded. The .java.policy file may be modified to grant applets more privileges.
FIXME: This actor should extend AudioReadBuffer?
Note: Requires Java 2 v1.3.0 or later.
LiveSoundEntity.ContainedObjectsIterator| Modifier and Type | Field and Description |
|---|---|
Parameter |
bufferLength
The length of the audio buffer to use.
|
StringAttribute |
sourceURL
The URL of the file to read from.
|
input, output_typesValid_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _deferChangeRequests, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKSCOMPLETED, NOT_READY, STOP_ITERATING| Constructor and Description |
|---|
AudioReadBuffer(CompositeEntity container,
java.lang.String name)
Construct an actor with the given container and name.
|
| Modifier and Type | Method and Description |
|---|---|
void |
attributeChanged(Attribute attribute)
Handle change requests for all parameters.
|
void |
fire()
Read the buffer address from the input port and output
the corresponding audio sample, if there is a token
available on the input port.
|
void |
initialize()
Open the sound file specified by the URL for reading.
|
boolean |
postfire()
This method causes one audio sample per channel to be
read from the specified file.
|
void |
wrapup()
Free up any system resources involved in the audio
reading process and close any open sound files.
|
_containedTypeConstraints, _customTypeConstraints, _defaultTypeConstraints, _fireAt, _fireAt, attributeTypeChanged, clone, clone, isBackwardTypeInferenceEnabled, newPort, typeConstraintList, typeConstraints_actorFiring, _actorFiring, _declareDelayDependency, addActorFiringListener, addInitializable, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, prefire, preinitialize, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName_addPort, _description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName_setParent, exportMoML, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _containedDecorators, _copyChangeRequestList, _debug, _debug, _debug, _debug, _debug, _executeChangeRequests, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _notifyHierarchyListenersAfterChange, _notifyHierarchyListenersBeforeChange, _propagateValue, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, addHierarchyListener, attributeDeleted, attributeList, attributeList, decorators, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getFullName, getModelErrorHandler, getName, getName, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, notifyOfNameChange, propagateValue, propagateValues, removeAttribute, removeChangeListener, removeDebugListener, removeHierarchyListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspaceequals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, waitcreateReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortListisFireFunctional, isStrict, iterate, prefire, stop, stopFire, terminateaddInitializable, preinitialize, removeInitializabledescription, getContainer, getDisplayName, getFullName, getName, getName, setNamegetDerivedLevel, getDerivedList, propagateValuepublic StringAttribute sourceURL
An exception will occur if the path references a non-existent or unsupported sound file.
public Parameter bufferLength
public AudioReadBuffer(CompositeEntity container, java.lang.String name) throws NameDuplicationException, IllegalActionException
container - The container.name - The name of this actor.IllegalActionException - If the actor cannot be contained
by the proposed container.NameDuplicationException - If the container already has an
actor with this name.public void attributeChanged(Attribute attribute) throws IllegalActionException
attributeChanged in class NamedObjattribute - The attribute that changed.IllegalActionException - If the change is not
allowed.public void initialize()
throws IllegalActionException
initialize in interface Initializableinitialize in class AtomicActor<TypedIOPort>IllegalActionException - If there is a problem opening
the specified URL, or if the file has an unsupported audio
format.public void fire()
throws IllegalActionException
The IntToken read from the input port specifies the buffer address to read from. The valid address range is 0 to bufferLength -1. If an invalid address is read, then the value 0.0 is output. If the the specified address is greater than bufferLength -1, then this actor will return false in postfire. The audio sample is converted to a DoubleToken with range [-1.0, 1.0] and sent to the output. Note that if a stereo sound file is specified, only the left channel will be used.
fire in interface Executablefire in class AtomicActor<TypedIOPort>IllegalActionException - Not thrown in this base class.public boolean postfire()
throws IllegalActionException
postfire in interface Executablepostfire in class AtomicActor<TypedIOPort>IllegalActionException - If there is a problem reading
from the specified sound file.public void wrapup()
throws IllegalActionException
wrapup in interface Initializablewrapup in class AtomicActor<TypedIOPort>IllegalActionException - If there is a
problem closing the file.