jdk/src/java.desktop/share/classes/com/sun/media/sound/AudioSynthesizer.java

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 * accompanied this code).
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package com.sun.media.sound;

import java.util.Map;

import javax.sound.midi.MidiSystem;
import javax.sound.midi.MidiUnavailableException;
import javax.sound.midi.Synthesizer;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.SourceDataLine;

/**
 * {@code AudioSynthesizer} is a {@code Synthesizer}
 * which renders it's output audio into {@code SourceDataLine}
 * or {@code AudioInputStream}.
 *
 * @see MidiSystem#getSynthesizer
 * @see Synthesizer
 *
 * @author Karl Helgason
 */
public interface AudioSynthesizer extends Synthesizer {

    /**
     * Obtains the current format (encoding, sample rate, number of channels,
     * etc.) of the synthesizer audio data.
     *
     * <p>If the synthesizer is not open and has never been opened, it returns
     * the default format.
     *
     * @return current audio data format
     * @see AudioFormat
     */
    AudioFormat getFormat();

    /**
     * Gets information about the possible properties for the synthesizer.
     *
     * @param info a proposed list of tag/value pairs that will be sent on open.
     * @return an array of {@code AudioSynthesizerPropertyInfo} objects
     * describing possible properties. This array may be an empty array if
     * no properties are required.
     */
    AudioSynthesizerPropertyInfo[] getPropertyInfo(Map<String, Object> info);

    /**
     * Opens the synthesizer and starts rendering audio into
     * {@code SourceDataLine}.
     *
     * <p>An application opening a synthesizer explicitly with this call
     * has to close the synthesizer by calling {@link #close}. This is
     * necessary to release system resources and allow applications to
     * exit cleanly.
     *
     * <p>Note that some synthesizers, once closed, cannot be reopened.
     * Attempts to reopen such a synthesizer will always result in
     * a {@code MidiUnavailableException}.
     *
     * @param line which {@code AudioSynthesizer} writes output audio into.
     * If {@code line} is null, then line from system default mixer is used.
     * @param info a {@code Map<String,Object>} object containing
     * properties for additional configuration supported by synthesizer.
     * If {@code info} is null then default settings are used.
     *
     * @throws MidiUnavailableException thrown if the synthesizer cannot be
     * opened due to resource restrictions.
     * @throws SecurityException thrown if the synthesizer cannot be
     * opened due to security restrictions.
     *
     * @see #close
     * @see #isOpen
     */
    void open(SourceDataLine line, Map<String, Object> info)
            throws MidiUnavailableException;

    /**
     * Opens the synthesizer and renders audio into returned
     * {@code AudioInputStream}.
     *
     * <p>An application opening a synthesizer explicitly with this call
     * has to close the synthesizer by calling {@link #close}. This is
     * necessary to release system resources and allow applications to
     * exit cleanly.
     *
     * <p>Note that some synthesizers, once closed, cannot be reopened.
     * Attempts to reopen such a synthesizer will always result in
     * a {@code MidiUnavailableException}.
     *
     * @param targetFormat specifies the {@code AudioFormat}
     * used in returned {@code AudioInputStream}.
     * @param info a {@code Map<String,Object>} object containing
     * properties for additional configuration supported by synthesizer.
     * If {@code info} is null then default settings are used.
     *
     * @throws MidiUnavailableException thrown if the synthesizer cannot be
     * opened due to resource restrictions.
     * @throws SecurityException thrown if the synthesizer cannot be
     * opened due to security restrictions.
     *
     * @see #close
     * @see #isOpen
     */
    AudioInputStream openStream(AudioFormat targetFormat,
                                Map<String, Object> info)
            throws MidiUnavailableException;
}