src/share/classes/javax/sound/sampled/ReverbType.java

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package javax.sound.sampled;


/**
 * The <code>ReverbType</code> class provides methods for
 * accessing various reverberation settings to be applied to
 * an audio signal.
 * <p>
 * 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.
 * <p>
 * The reverberation parameters provided by <code>ReverbType</code> 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.
 * <p>
 * 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.
 * <p>
 * If implementing JavaSound on a I3DL2-compliant device:
 * <ul>
 * <li>Filtering is disabled (high-frequency attenuations are set to 0.0 dB)
 * <li>Density parameters are set to midway between minimum and maximum
 * </ul>
 * <p>
 * The following table shows what parameter values an implementation might use for a
 * representative set of reverberation settings.
 * <p>
 *
 * <b>Reverberation Types and Parameters</b>
 * <p>
 * <table border=1 cellpadding=5 summary="reverb types and params: decay time, late intensity, late delay, early intensity, and early delay">
 *
 * <tr>
 *  <th>Type</th>
 *  <th>Decay Time (ms)</th>
 *  <th>Late Intensity (dB)</th>
 *  <th>Late Delay (ms)</th>
 *  <th>Early Intensity (dB)</th>
 *  <th>Early Delay(ms)</th>
 * </tr>
 *
 * <tr>
 *  <td>Cavern</td>
 *  <td>2250</td>
 *  <td>-2.0</td>
 *  <td>41.3</td>
 *  <td>-1.4</td>
 *  <td>10.3</td>
 * </tr>
 *
 * <tr>
 *  <td>Dungeon</td>
 *  <td>1600</td>
 *  <td>-1.0</td>
 *  <td>10.3</td>
 *  <td>-0.7</td>
 *  <td>2.6</td>
 * </tr>
 *
 * <tr>
 *  <td>Garage</td>
 *  <td>900</td>
 *  <td>-6.0</td>
 *  <td>14.7</td>
 *  <td>-4.0</td>
 *  <td>3.9</td>
 * </tr>
 *
 * <tr>
 *  <td>Acoustic Lab</td>
 *  <td>280</td>
 *  <td>-3.0</td>
 *  <td>8.0</td>
 *  <td>-2.0</td>
 *  <td>2.0</td>
 * </tr>
 *
 * <tr>
 *  <td>Closet</td>
 *  <td>150</td>
 *  <td>-10.0</td>
 *  <td>2.5</td>
 *  <td>-7.0</td>
 *  <td>0.6</td>
 * </tr>
 *
 * </table>
 *
 * @author Kara Kytle
 * @since 1.3
 */
public class ReverbType {

    /**
     * Descriptive name of the reverb type..
     */
    private String name;

    /**
     * Early reflection delay in microseconds.
     */
    private int earlyReflectionDelay;

    /**
     * Early reflection intensity.
     */
    private float earlyReflectionIntensity;

    /**
     * Late reflection delay in microseconds.
     */
    private int lateReflectionDelay;

    /**
     * Late reflection intensity.
     */
    private float lateReflectionIntensity;

    /**
     * Total decay time
     */
    private int decayTime;


    /**
     * Constructs a new reverb type that has the specified reverberation
     * parameter values.
     * @param name the name of the new reverb type, or a zero-length <code>String</code>
     * @param earlyReflectionDelay the new type's early reflection delay time in microseconds
     * @param earlyReflectionIntensity the new type's early reflection intensity in dB
     * @param lateReflectionDelay the new type's late reflection delay time in microseconds
     * @param lateReflectionIntensity the new type's late reflection intensity in dB
     * @param decayTime the new type's decay time in microseconds
     */
    protected ReverbType(String name, int earlyReflectionDelay, float earlyReflectionIntensity, int lateReflectionDelay, float lateReflectionIntensity, int decayTime) {

        this.name = name;
        this.earlyReflectionDelay = earlyReflectionDelay;
        this.earlyReflectionIntensity = earlyReflectionIntensity;
        this.lateReflectionDelay = lateReflectionDelay;
        this.lateReflectionIntensity = lateReflectionIntensity;
        this.decayTime = decayTime;
    }


    /**
     * Obtains the name of this reverb type.
     * @return the name of this reverb type
     * @since 1.5
     */
    public String getName() {
            return name;
    }


    /**
     * 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.
     * @return  early reflection delay time for this reverb type, in microseconds
     */
    public final int getEarlyReflectionDelay() {
        return earlyReflectionDelay;
    }


    /**
     * Returns the early reflection intensity in decibels.
     * This is the amplitude attenuation of the first early reflections
     * relative to the direct signal.
     * @return  early reflection intensity for this reverb type, in dB
     */
    public final float getEarlyReflectionIntensity() {
        return earlyReflectionIntensity;
    }


    /**
     * 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.
     * @return  late reflection delay time for this reverb type, in microseconds
     */
    public final int getLateReflectionDelay() {
        return lateReflectionDelay;
    }


    /**
     * Returns the late reflection intensity in decibels.
     * This is the amplitude attenuation of the first late reflections
     * relative to the direct signal.
     * @return  late reflection intensity for this reverb type, in dB
     */
    public final float getLateReflectionIntensity() {
        return lateReflectionIntensity;
    }


    /**
     * 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.
     * @return  the decay time of the late reflections, in microseconds
     */
    public final int getDecayTime() {
        return decayTime;
    }


    /**
     * Indicates whether the specified object is equal to this reverb type,
     * returning <code>true</code> if the objects are identical.
     * @param obj the reference object with which to compare
     * @return <code>true</code> if this reverb type is the same as
     * <code>obj</code>; <code>false</code> otherwise
     */
    public final boolean equals(Object obj) {
        return super.equals(obj);
    }


    /**
     * Finalizes the hashcode method.
     */
    public final int hashCode() {
        return super.hashCode();
    }


    /**
     * Provides a <code>String</code> 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.
     * @return reverberation type name and description
     */
    public final String toString() {

        //$$fb2001-07-20: fix for bug 4385060: The "name" attribute of class "ReverbType" is not accessible.
        //return (super.toString() + ", early reflection delay " + earlyReflectionDelay +
        return (name + ", early reflection delay " + earlyReflectionDelay +
                " ns, early reflection intensity " + earlyReflectionIntensity +
                " dB, late deflection delay " + lateReflectionDelay +
                " ns, late reflection intensity " + lateReflectionIntensity +
                " dB, decay time " +  decayTime);
    }

} // class ReverbType