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package javax.sound.sampled;



A mixer is an audio device with one or more lines.  It need not be
designed for mixing audio signals.  A mixer that actually mixes audio
has multiple input (source) lines and at least one output (target) line.
The former are often instances of classes that implement
SourceDataLine,
and the latter, TargetDataLine.  Port
objects, too, are either source lines or target lines.
A mixer can accept prerecorded, loopable sound as input, by having
some of its source lines be instances of objects that implement the
Clip interface.


Through methods of the Line interface, which Mixer extends,
a mixer might provide a set of controls that are global to the mixer.  For example,
the mixer can have a master gain control.  These global controls are distinct
from the controls belonging to each of the mixer's individual lines.


Some mixers, especially
those with internal digital mixing capabilities, may provide
additional capabilities by implementing the DataLine interface.


A mixer can support synchronization of its lines.  When one line in
a synchronized group is started or stopped, the other lines in the group
automatically start or stop simultaneously with the explicitly affected one.

Author:Kara Kytle
Since:1.3
/**
 * A mixer is an audio device with one or more lines.  It need not be
 * designed for mixing audio signals.  A mixer that actually mixes audio
 * has multiple input (source) lines and at least one output (target) line.
 * The former are often instances of classes that implement
 * <code>{@link SourceDataLine}</code>,
 * and the latter, <code>{@link TargetDataLine}</code>.  <code>{@link Port}</code>
 * objects, too, are either source lines or target lines.
 * A mixer can accept prerecorded, loopable sound as input, by having
 * some of its source lines be instances of objects that implement the
 * <code>{@link Clip}</code> interface.
 * <p>
 * Through methods of the <code>Line</code> interface, which <code>Mixer</code> extends,
 * a mixer might provide a set of controls that are global to the mixer.  For example,
 * the mixer can have a master gain control.  These global controls are distinct
 * from the controls belonging to each of the mixer's individual lines.
 * <p>
 * Some mixers, especially
 * those with internal digital mixing capabilities, may provide
 * additional capabilities by implementing the <code>DataLine</code> interface.
 * <p>
 * A mixer can support synchronization of its lines.  When one line in
 * a synchronized group is started or stopped, the other lines in the group
 * automatically start or stop simultaneously with the explicitly affected one.
 *
 * @author Kara Kytle
 * @since 1.3
 */
public interface Mixer extends Line {

    
Obtains information about this mixer, including the product's name,
version, vendor, etc.

See Also:
Returns:a mixer info object that describes this mixer
/**
     * Obtains information about this mixer, including the product's name,
     * version, vendor, etc.
     * @return a mixer info object that describes this mixer
     * @see Mixer.Info
     */
    public Info getMixerInfo();


    
Obtains information about the set of source lines supported
by this mixer.
Some source lines may only be available when this mixer is open.

Returns:array of Line.Info objects representing source lines
for this mixer.  If no source lines are supported,
an array of length 0 is returned.
/**
     * Obtains information about the set of source lines supported
     * by this mixer.
     * Some source lines may only be available when this mixer is open.
     * @return array of <code>Line.Info</code> objects representing source lines
     * for this mixer.  If no source lines are supported,
     * an array of length 0 is returned.
     */
    public Line.Info[] getSourceLineInfo();

    
Obtains information about the set of target lines supported
by this mixer.
Some target lines may only be available when this mixer is open.

Returns:array of Line.Info objects representing target lines
for this mixer.  If no target lines are supported,
an array of length 0 is returned.
/**
     * Obtains information about the set of target lines supported
     * by this mixer.
     * Some target lines may only be available when this mixer is open.
     * @return array of <code>Line.Info</code> objects representing target lines
     * for this mixer.  If no target lines are supported,
     * an array of length 0 is returned.
     */
    public Line.Info[] getTargetLineInfo();


    
Obtains information about source lines of a particular type supported
by the mixer.
Some source lines may only be available when this mixer is open.

Params:
  • info – a Line.Info object describing lines about which information
is queried
Returns:an array of Line.Info objects describing source lines matching
the type requested.  If no matching source lines are supported, an array of length 0
is returned.
/**
     * Obtains information about source lines of a particular type supported
     * by the mixer.
     * Some source lines may only be available when this mixer is open.
     * @param info a <code>Line.Info</code> object describing lines about which information
     * is queried
     * @return an array of <code>Line.Info</code> objects describing source lines matching
     * the type requested.  If no matching source lines are supported, an array of length 0
     * is returned.
     */
    public Line.Info[] getSourceLineInfo(Line.Info info);


    
Obtains information about target lines of a particular type supported
by the mixer.
Some target lines may only be available when this mixer is open.

Params:
  • info – a Line.Info object describing lines about which information
is queried
Returns:an array of Line.Info objects describing target lines matching
the type requested.  If no matching target lines are supported, an array of length 0
is returned.
/**
     * Obtains information about target lines of a particular type supported
     * by the mixer.
     * Some target lines may only be available when this mixer is open.
     * @param info a <code>Line.Info</code> object describing lines about which information
     * is queried
     * @return an array of <code>Line.Info</code> objects describing target lines matching
     * the type requested.  If no matching target lines are supported, an array of length 0
     * is returned.
     */
    public Line.Info[] getTargetLineInfo(Line.Info info);


    
Indicates whether the mixer supports a line (or lines) that match
the specified Line.Info object.
Some lines may only be supported when this mixer is open.

Params:
  • info – describes the line for which support is queried
Returns:true if at least one matching line is
supported, false otherwise
/**
     * Indicates whether the mixer supports a line (or lines) that match
     * the specified <code>Line.Info</code> object.
     * Some lines may only be supported when this mixer is open.
     * @param info describes the line for which support is queried
     * @return <code>true</code> if at least one matching line is
     * supported, <code>false</code> otherwise
     */
    public boolean isLineSupported(Line.Info info);

    
Obtains a line that is available for use and that matches the description
in the specified Line.Info object.

If a DataLine is requested, and info
is an instance of DataLine.Info specifying at
least one fully qualified audio format, the last one
will be used as the default format of the returned
DataLine.

Params:
  • info – describes the desired line
Throws:
/**
     * Obtains a line that is available for use and that matches the description
     * in the specified <code>Line.Info</code> object.
     *
     * <p>If a <code>DataLine</code> is requested, and <code>info</code>
     * is an instance of <code>DataLine.Info</code> specifying at
     * least one fully qualified audio format, the last one
     * will be used as the default format of the returned
     * <code>DataLine</code>.
     *
     * @param info describes the desired line
     * @throws LineUnavailableException if a matching line
     * is not available due to resource restrictions
     * @throws IllegalArgumentException if this mixer does
     * not support any lines matching the description
     * @throws SecurityException if a matching line
     * is not available due to security restrictions
     */
    public Line getLine(Line.Info info) throws LineUnavailableException;

    //$$fb 2002-04-12: fix for 4667258: behavior of Mixer.getMaxLines(Line.Info) method doesn't match the spec
    
Obtains the approximate maximum number of lines of the requested type that can be open
simultaneously on the mixer.
Certain types of mixers do not have a hard bound and may allow opening more lines.
Since certain lines are a shared resource, a mixer may not be able to open the maximum
number of lines if another process has opened lines of this mixer.
The requested type is any line that matches the description in
the provided Line.Info object.  For example, if the info
object represents a speaker
port, and the mixer supports exactly one speaker port, this method
should return 1.  If the info object represents a source data line
and the mixer supports the use of 32 source data lines simultaneously,
the return value should be 32.
If there is no limit, this function returns AudioSystem.NOT_SPECIFIED.

Params:
  • info – a Line.Info that describes the line for which
the number of supported instances is queried
Returns:the maximum number of matching lines supported, or AudioSystem.NOT_SPECIFIED
/**
     * Obtains the approximate maximum number of lines of the requested type that can be open
     * simultaneously on the mixer.
     *
     * Certain types of mixers do not have a hard bound and may allow opening more lines.
     * Since certain lines are a shared resource, a mixer may not be able to open the maximum
     * number of lines if another process has opened lines of this mixer.
     *
     * The requested type is any line that matches the description in
     * the provided <code>Line.Info</code> object.  For example, if the info
     * object represents a speaker
     * port, and the mixer supports exactly one speaker port, this method
     * should return 1.  If the info object represents a source data line
     * and the mixer supports the use of 32 source data lines simultaneously,
     * the return value should be 32.
     * If there is no limit, this function returns <code>AudioSystem.NOT_SPECIFIED</code>.
     * @param info a <code>Line.Info</code> that describes the line for which
     * the number of supported instances is queried
     * @return the maximum number of matching lines supported, or <code>AudioSystem.NOT_SPECIFIED</code>
     */
    public int getMaxLines(Line.Info info);


    
Obtains the set of all source lines currently open to this mixer.

Throws:
  • SecurityException – if the matching lines
are not available due to security restrictions
Returns:the source lines currently open to the mixer.
If no source lines are currently open to this mixer,  an
array of length 0 is returned.
/**
     * Obtains the set of all source lines currently open to this mixer.
     *
     * @return the source lines currently open to the mixer.
     * If no source lines are currently open to this mixer,  an
     * array of length 0 is returned.
     * @throws SecurityException if the matching lines
     * are not available due to security restrictions
     */
    public Line[] getSourceLines();

    
Obtains the set of all target lines currently open from this mixer.

Throws:
  • SecurityException – if the matching lines
are not available due to security restrictions
Returns:target lines currently open from the mixer.
If no target lines are currently open from this mixer, an
array of length 0 is returned.
/**
     * Obtains the set of all target lines currently open from this mixer.
     *
     * @return target lines currently open from the mixer.
     * If no target lines are currently open from this mixer, an
     * array of length 0 is returned.
     * @throws SecurityException if the matching lines
     * are not available due to security restrictions
     */
    public Line[] getTargetLines();

    
Synchronizes two or more lines.  Any subsequent command that starts or stops
audio playback or capture for one of these lines will exert the
same effect on the other lines in the group, so that they start or stop playing or
capturing data simultaneously.

Params:
  • lines – the lines that should be synchronized
  • maintainSync – true if the synchronization
must be precisely maintained (i.e., the synchronization must be sample-accurate)
at all times during operation of the lines , or false
if precise synchronization is required only during start and stop operations
Throws:
  • IllegalArgumentException – if the lines cannot be synchronized.
This may occur if the lines are of different types or have different
formats for which this mixer does not support synchronization, or if
all lines specified do not belong to this mixer.
/**
     * Synchronizes two or more lines.  Any subsequent command that starts or stops
     * audio playback or capture for one of these lines will exert the
     * same effect on the other lines in the group, so that they start or stop playing or
     * capturing data simultaneously.
     *
     * @param lines the lines that should be synchronized
     * @param maintainSync <code>true</code> if the synchronization
     * must be precisely maintained (i.e., the synchronization must be sample-accurate)
     * at all times during operation of the lines , or <code>false</code>
     * if precise synchronization is required only during start and stop operations
     *
     * @throws IllegalArgumentException if the lines cannot be synchronized.
     * This may occur if the lines are of different types or have different
     * formats for which this mixer does not support synchronization, or if
     * all lines specified do not belong to this mixer.
     */
    public void synchronize(Line[] lines, boolean maintainSync);

    
Releases synchronization for the specified lines.  The array must
be identical to one for which synchronization has already been
established; otherwise an exception may be thrown.  However, null
may be specified, in which case all currently synchronized lines that belong
to this mixer are unsynchronized.

Params:
  • lines – the synchronized lines for which synchronization should be
released, or null for all this mixer's synchronized lines
Throws:
  • IllegalArgumentException – if the lines cannot be unsynchronized.
This may occur if the argument specified does not exactly match a set
of lines for which synchronization has already been established.
/**
     * Releases synchronization for the specified lines.  The array must
     * be identical to one for which synchronization has already been
     * established; otherwise an exception may be thrown.  However, <code>null</code>
     * may be specified, in which case all currently synchronized lines that belong
     * to this mixer are unsynchronized.
     * @param lines the synchronized lines for which synchronization should be
     * released, or <code>null</code> for all this mixer's synchronized lines
     *
     * @throws IllegalArgumentException if the lines cannot be unsynchronized.
     * This may occur if the argument specified does not exactly match a set
     * of lines for which synchronization has already been established.
     */
    public void unsynchronize(Line[] lines);


    
Reports whether this mixer supports synchronization of the specified set of lines.

Params:
  • lines – the set of lines for which synchronization support is queried
  • maintainSync – true if the synchronization
must be precisely maintained (i.e., the synchronization must be sample-accurate)
at all times during operation of the lines , or false
if precise synchronization is required only during start and stop operations
Returns:true if the lines can be synchronized, false
otherwise
/**
     * Reports whether this mixer supports synchronization of the specified set of lines.
     *
     * @param lines the set of lines for which synchronization support is queried
     * @param maintainSync <code>true</code> if the synchronization
     * must be precisely maintained (i.e., the synchronization must be sample-accurate)
     * at all times during operation of the lines , or <code>false</code>
     * if precise synchronization is required only during start and stop operations
     *
     * @return <code>true</code> if the lines can be synchronized, <code>false</code>
     * otherwise
     */
    public boolean isSynchronizationSupported(Line[] lines, boolean maintainSync);


    
The Mixer.Info class represents information about an audio mixer, including the product's name, version, and vendor, along with a textual description. This information may be retrieved through the getMixerInfo method of the Mixer interface.

Author:Kara Kytle
Since:1.3
/**
     * The <code>Mixer.Info</code> class represents information about an audio mixer,
     * including the product's name, version, and vendor, along with a textual
     * description.  This information may be retrieved through the
     * {@link Mixer#getMixerInfo() getMixerInfo}
     * method of the <code>Mixer</code> interface.
     *
     * @author Kara Kytle
     * @since 1.3
     */
    public static class Info {

        
Mixer name.

/**
         * Mixer name.
         */
        private final String name;

        
Mixer vendor.

/**
         * Mixer vendor.
         */
        private final String vendor;

        
Mixer description.

/**
         * Mixer description.
         */
        private final String description;

        
Mixer version.

/**
         * Mixer version.
         */
        private final String version;

        
Constructs a mixer's info object, passing it the given
textual information.

Params:
  • name – the name of the mixer
  • vendor – the company who manufactures or creates the hardware
or software mixer
  • description – descriptive text about the mixer
  • version – version information for the mixer
/**
         * Constructs a mixer's info object, passing it the given
         * textual information.
         * @param name the name of the mixer
         * @param vendor the company who manufactures or creates the hardware
         * or software mixer
         * @param description descriptive text about the mixer
         * @param version version information for the mixer
         */
        protected Info(String name, String vendor, String description, String version) {

            this.name = name;
            this.vendor = vendor;
            this.description = description;
            this.version = version;
        }


        
Indicates whether two info objects are equal, returning true if
they are identical.

Params:
  • obj – the reference object with which to compare this info
object
Returns:true if this info object is the same as the
obj argument; false otherwise
/**
         * Indicates whether two info objects are equal, returning <code>true</code> if
         * they are identical.
         * @param obj the reference object with which to compare this info
         * object
         * @return <code>true</code> if this info object is the same as the
         * <code>obj</code> argument; <code>false</code> otherwise
         */
        public final boolean equals(Object obj) {
            return super.equals(obj);
        }

        
Finalizes the hashcode method.

Returns:the hashcode for this object
/**
         * Finalizes the hashcode method.
         *
         * @return the hashcode for this object
         */
        public final int hashCode() {
            return super.hashCode();
        }

        
Obtains the name of the mixer.

Returns:a string that names the mixer
/**
         * Obtains the name of the mixer.
         * @return a string that names the mixer
         */
        public final String getName() {
            return name;
        }

        
Obtains the vendor of the mixer.

Returns:a string that names the mixer's vendor
/**
         * Obtains the vendor of the mixer.
         * @return a string that names the mixer's vendor
         */
        public final String getVendor() {
            return vendor;
        }

        
Obtains the description of the mixer.

Returns:a textual description of the mixer
/**
         * Obtains the description of the mixer.
         * @return a textual description of the mixer
         */
        public final String getDescription() {
            return description;
        }

        
Obtains the version of the mixer.

Returns:textual version information for the mixer
/**
         * Obtains the version of the mixer.
         * @return textual version information for the mixer
         */
        public final String getVersion() {
            return version;
        }

        
Provides a string representation of the mixer info.

Returns:a string describing the info object
/**
         * Provides a string representation of the mixer info.
         * @return a string describing the info object
         */
        public final String toString() {
            return (name + ", version " + version);
        }
    } // class Info
}