ReverbType (Java 2 Platform SE v1.4.1) - JDK 5 Documentation v1.4.1, Java 2 SDK 英文文档

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javax.sound.sampled
Class ReverbType

java.lang.Object
  |
  +--javax.sound.sampled.ReverbType

public class ReverbType
extends Object

The ReverbType class provides methods for accessing various reverberation settings to be applied to an audio signal.

Reverberation simulates the reflection of sound off of the walls, ceiling, and floor of a room. Depending on the size of the room, and how absorbent or reflective the materials in the room's surfaces are, the sound might bounce around for a long time before dying away.

The reverberation parameters provided by ReverbType consist of the delay time and intensity of early reflections, the delay time and intensity of late reflections, and an overall decay time. Early reflections are the initial individual low-order reflections of the direct signal off the surfaces in the room. The late Relections are the dense, high-order reflections that characterize the room's reverberation. The delay times for the start of these two reflection types give the listener a sense of the overall size and complexity of the room's shape and contents. The larger the room, the longer the reflection delay times. The early and late reflections' intensities define the gain (in decibels) of the reflected signals as compared to the direct signal. These intensities give the listener an impression of the absorptive nature of the surfaces and objects in the room. The decay time defines how long the reverberation takes to exponentially decay until it is no longer perceptible ("effective zero"). The larger and less absorbent the surfaces, the longer the decay time.

The set of parameters defined here may not include all aspects of reverberation as specified by some systems. For example, the Midi Manufacturer's Association (MMA) has an Interactive Audio Special Interest Group (IASIG), which has a 3-D Working Group that has defined a Level 2 Spec (I3DL2). I3DL2 supports filtering of reverberation and control of reverb density. These properties are not included in the JavaSound 1.0 definition of a reverb control. In such a case, the implementing system should either extend the defined reverb control to include additional parameters, or else interpret the system's additional capabilities in a way that fits the model described here.

If implementing JavaSound on a I3DL2-compliant device:

Filtering is disabled (high-frequency attenuations are set to 0.0 dB)
Density parameters are set to midway between minimum and maximum

The following table shows what parameter values an implementation might use for a representative set of reverberation settings.

Reverberation Types and Parameters

Type Decay Time (ms) Late Intensity (dB) Late Delay (ms) Early Intensity (dB) Early Delay(ms)

Cavern 2250 -2.0 41.3 -1.4 10.3

Dungeon 1600 -1.0 10.3 -0.7 2.6

Garage 900 -6.0 14.7 -4.0 3.9

Acoustic Lab 280 -3.0 8.0 -2.0 2.0

Closet 150 -10.0 2.5 -7.0 0.6

Type	Decay Time (ms)	Late Intensity (dB)	Late Delay (ms)	Early Intensity (dB)	Early Delay(ms)
Cavern	2250	-2.0	41.3	-1.4	10.3
Dungeon	1600	-1.0	10.3	-0.7	2.6
Garage	900	-6.0	14.7	-4.0	3.9
Acoustic Lab	280	-3.0	8.0	-2.0	2.0
Closet	150	-10.0	2.5	-7.0	0.6

Since:: 1.3

Constructor Summary

protected ReverbType(String name, int earlyReflectionDelay, float earlyReflectionIntensity, int lateReflectionDelay, float lateReflectionIntensity, int decayTime)
          Constructs a new reverb type that has the specified reverberation parameter values.

Method Summary

boolean equals(Object obj)
          Indicates whether the specified object is equal to this reverb type, returning true if the objects are identical.

int getDecayTime()
          Obtains the decay time, which is the amount of time over which the late reflections attenuate to effective zero.

int getEarlyReflectionDelay()
          Returns the early reflection delay time in microseconds.

float getEarlyReflectionIntensity()
          Returns the early reflection intensity in decibels.

int getLateReflectionDelay()
          Returns the late reflection delay time in microseconds.

float getLateReflectionIntensity()
          Returns the late reflection intensity in decibels.

int hashCode()
          Finalizes the hashcode method.

String toString()
          Provides a String representation of the reverb type, including its name and its parameter settings.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ReverbType

protected ReverbType(String name,
                     int earlyReflectionDelay,
                     float earlyReflectionIntensity,
                     int lateReflectionDelay,
                     float lateReflectionIntensity,
                     int decayTime)

Constructs a new reverb type that has the specified reverberation parameter values.
Parameters:: name - the name of the new reverb type, or a zero-length String; earlyReflectionDelay - the new type's early reflection delay time in microseconds; earlyReflectionIntensity - the new type's early reflection intensity in dB; lateReflectionDelay - the new type's late reflection delay time in microseconds; lateReflectionIntensity - the new type's late reflection intensity in dB; decayTime - the new type's decay time in microseconds

Method Detail

getEarlyReflectionDelay

public final int getEarlyReflectionDelay()

Returns the early reflection delay time in microseconds. This is the amount of time between when the direct signal is heard and when the first early reflections are heard.

Returns:: early reflection delay time for this reverb type, in microseconds

getEarlyReflectionIntensity

public final float getEarlyReflectionIntensity()

Returns the early reflection intensity in decibels. This is the amplitude attenuation of the first early reflections relative to the direct signal.

Returns:: early reflection intensity for this reverb type, in dB

getLateReflectionDelay

public final int getLateReflectionDelay()

Returns the late reflection delay time in microseconds. This is the amount of time between when the first early reflections are heard and when the first late reflections are heard.

Returns:: late reflection delay time for this reverb type, in microseconds

getLateReflectionIntensity

public final float getLateReflectionIntensity()

Returns the late reflection intensity in decibels. This is the amplitude attenuation of the first late reflections relative to the direct signal.

Returns:: late reflection intensity for this reverb type, in dB

getDecayTime

public final int getDecayTime()

Obtains the decay time, which is the amount of time over which the late reflections attenuate to effective zero. The effective zero value is implementation-dependent.

Returns:: the decay time of the late reflections, in microseconds

equals

public final boolean equals(Object obj)

Indicates whether the specified object is equal to this reverb type, returning true if the objects are identical.

Overrides:: equals in class Object

Parameters:: obj - the reference object with which to compare
Returns:: true if this reverb type is the same as obj; false otherwise
See Also:: Object.hashCode(), Hashtable

hashCode

public final int hashCode()

Finalizes the hashcode method.

Overrides:: hashCode in class Object

Returns:: a hash code value for this object.
See Also:: Object.equals(java.lang.Object), Hashtable

toString

public final String toString()

Provides a String representation of the reverb type, including its name and its parameter settings. The exact contents of the string may vary between implementations of Java Sound.

Overrides:: toString in class Object

Returns:: reverberation type name and description