VolumeShaper
public
final
class
VolumeShaper
extends Object
implements
AutoCloseable
java.lang.Object | |
↳ | android.media.VolumeShaper |
The VolumeShaper
class is used to automatically control audio volume during media
playback, allowing simple implementation of transition effects and ducking.
It is created from implementations of VolumeAutomation
,
such as MediaPlayer
and AudioTrack
(referred to as "players" below),
by MediaPlayer.createVolumeShaper
or AudioTrack.createVolumeShaper
.
A VolumeShaper
is intended for short volume changes.
If the audio output sink changes during
a VolumeShaper
transition, the precise curve position may be lost, and the
VolumeShaper
may advance to the end of the curve for the new audio output sink.
The VolumeShaper
appears as an additional scaling on the audio output,
and adjusts independently of track or stream volume controls.
Summary
Nested classes | |
---|---|
class |
VolumeShaper.Configuration
The |
class |
VolumeShaper.Operation
The |
Public methods | |
---|---|
void
|
apply(VolumeShaper.Operation operation)
Applies the |
void
|
close()
Releases the |
float
|
getVolume()
Returns the current volume scale attributable to the |
void
|
replace(VolumeShaper.Configuration configuration, VolumeShaper.Operation operation, boolean join)
Replaces the current |
Protected methods | |
---|---|
void
|
finalize()
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. |
Inherited methods | |
---|---|
Public methods
apply
public void apply (VolumeShaper.Operation operation)
Applies the VolumeShaper.Operation
to the VolumeShaper
.
Applying VolumeShaper.Operation.PLAY
after PLAY
or VolumeShaper.Operation.REVERSE
after
REVERSE
has no effect.
Applying VolumeShaper.Operation.PLAY
when the player
hasn't started will synchronously start the VolumeShaper
when
playback begins.
Parameters | |
---|---|
operation |
VolumeShaper.Operation : the operation to apply.
This value cannot be null . |
Throws | |
---|---|
IllegalStateException |
if the player is uninitialized or if there
is a critical failure. In that case, the VolumeShaper should be
recreated. |
close
public void close ()
Releases the VolumeShaper
object; any volume scale due to the
VolumeShaper
is removed after closing.
If the volume does not reach 1.f when the VolumeShaper
is closed
(or finalized), there may be an abrupt change of volume.
close()
may be safely called after a prior close()
.
This class implements the Java AutoClosable
interface and
may be used with try-with-resources.
getVolume
public float getVolume ()
Returns the current volume scale attributable to the VolumeShaper
.
This is the last volume from the VolumeShaper
used for the player,
or the initial volume if the VolumeShaper
hasn't been started with
VolumeShaper.Operation.PLAY
.
Returns | |
---|---|
float |
the volume, linearly represented as a value between 0.f and 1.f. |
Throws | |
---|---|
IllegalStateException |
if the player is uninitialized or if there
is a critical failure. In that case, the VolumeShaper should be
recreated. |
replace
public void replace (VolumeShaper.Configuration configuration, VolumeShaper.Operation operation, boolean join)
Replaces the current VolumeShaper
configuration
with a new configuration
.
This allows the user to change the volume shape
while the existing VolumeShaper
is in effect.
The effect of replace()
is similar to an atomic close of
the existing VolumeShaper
and creation of a new VolumeShaper
.
If the operation
is VolumeShaper.Operation.PLAY
then the
new curve starts immediately.
If the operation
is
VolumeShaper.Operation.REVERSE
, then the new curve will
be delayed until PLAY
is applied.
Parameters | |
---|---|
configuration |
VolumeShaper.Configuration : the new configuration to use.
This value cannot be null . |
operation |
VolumeShaper.Operation : the operation to apply to the VolumeShaper
This value cannot be null . |
join |
boolean : if true, match the start volume of the
new configuration to the current volume of the existing
VolumeShaper , to avoid discontinuity. |
Throws | |
---|---|
IllegalStateException |
if the player is uninitialized or if there
is a critical failure. In that case, the VolumeShaper should be
recreated. |
Protected methods
finalize
protected void finalize ()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
A subclass overrides the finalize
method to dispose of
system resources or to perform other cleanup.
The general contract of finalize
is that it is invoked
if and when the Java virtual
machine has determined that there is no longer any
means by which this object can be accessed by any thread that has
not yet died, except as a result of an action taken by the
finalization of some other object or class which is ready to be
finalized. The finalize
method may take any action, including
making this object available again to other threads; the usual purpose
of finalize
, however, is to perform cleanup actions before
the object is irrevocably discarded. For example, the finalize method
for an object that represents an input/output connection might perform
explicit I/O transactions to break the connection before the object is
permanently discarded.
The finalize
method of class Object
performs no
special action; it simply returns normally. Subclasses of
Object
may override this definition.
The Java programming language does not guarantee which thread will
invoke the finalize
method for any given object. It is
guaranteed, however, that the thread that invokes finalize will not
be holding any user-visible synchronization locks when finalize is
invoked. If an uncaught exception is thrown by the finalize method,
the exception is ignored and finalization of that object terminates.
After the finalize
method has been invoked for an object, no
further action is taken until the Java virtual machine has again
determined that there is no longer any means by which this object can
be accessed by any thread that has not yet died, including possible
actions by other objects or classes which are ready to be finalized,
at which point the object may be discarded.
The finalize
method is never invoked more than once by a Java
virtual machine for any given object.
Any exception thrown by the finalize
method causes
the finalization of this object to be halted, but is otherwise
ignored.
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Last updated 2024-12-18 UTC.