Java tutorial
/* * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ 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 {@link SourceDataLine}, and the * latter, {@link TargetDataLine}. {@link 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 {@link Clip} interface. * <p> * Through methods of the {@code Line} interface, which {@code 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. * <p> * Some mixers, especially those with internal digital mixing capabilities, may * provide additional capabilities by implementing the {@code DataLine} * 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. * * @return a mixer info object that describes this mixer * @see Info */ 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. * * @return array of {@code Line.Info} objects representing source lines for * this mixer. If no source lines are supported, an array of length * 0 is returned. */ 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. * * @return array of {@code Line.Info} objects representing target lines for * this mixer. If no target lines are supported, an array of length * 0 is returned. */ 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. * * @param info a {@code Line.Info} object describing lines about which * information is queried * @return an array of {@code Line.Info} objects describing source lines * matching the type requested. If no matching source lines are * supported, an array of length 0 is returned. */ 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. * * @param info a {@code Line.Info} object describing lines about which * information is queried * @return an array of {@code Line.Info} objects describing target lines * matching the type requested. If no matching target lines are * supported, an array of length 0 is returned. */ Line.Info[] getTargetLineInfo(Line.Info info); /** * Indicates whether the mixer supports a line (or lines) that match the * specified {@code Line.Info} 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} if at least one matching line is supported, * {@code false} otherwise */ boolean isLineSupported(Line.Info info); /** * Obtains a line that is available for use and that matches the description * in the specified {@code Line.Info} object. * <p> * If a {@code DataLine} is requested, and {@code info} is an instance of * {@code DataLine.Info} specifying at least one fully qualified audio * format, the last one will be used as the default format of the returned * {@code DataLine}. * * @param info describes the desired line * @return a line that is available for use and that matches the description * in the specified {@code Line.Info} object * @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 */ 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. * <p> * 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. * <p> * The requested type is any line that matches the description in the * provided {@code 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 {@link AudioSystem#NOT_SPECIFIED}. * * @param info a {@code Line.Info} 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} */ int getMaxLines(Line.Info info); /** * 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 */ Line[] getSourceLines(); /** * 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 */ 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. * * @param lines the lines that should be synchronized * @param maintainSync {@code 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 * {@code 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. */ 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, {@code null} 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} 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. */ void unsynchronize(Line[] lines); /** * 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} 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} if precise synchronization is required only during * start and stop operations * @return {@code true} if the lines can be synchronized, {@code false} * otherwise */ boolean isSynchronizationSupported(Line[] lines, boolean maintainSync); /** * The {@code 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 * {@link Mixer#getMixerInfo() getMixerInfo} method of the {@code Mixer} * interface. * * @author Kara Kytle * @since 1.3 */ class Info { /** * Mixer name. */ private final String name; /** * Mixer vendor. */ private final String vendor; /** * Mixer description. */ private final String description; /** * Mixer version. */ private final String version; /** * 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 the specified object is equal to this info object, * returning {@code true} if the objects are the same. * * @param obj the reference object with which to compare * @return {@code true} if the specified object is equal to this info * object; {@code false} otherwise */ @Override public final boolean equals(Object obj) { return super.equals(obj); } /** * Returns a hash code value for this info object. * * @return a hash code value for this info object */ @Override public final int hashCode() { return super.hashCode(); } /** * 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. * * @return a string that names the mixer's vendor */ public final String getVendor() { return vendor; } /** * 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. * * @return textual version information for the mixer */ public final String getVersion() { return version; } /** * Provides a string representation of the mixer info. * * @return a string describing the info object */ @Override public final String toString() { return (name + ", version " + version); } } }