1 /*
2 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.sound.sampled;
27
28
29 /**
30 * A mixer is an audio device with one or more lines. It need not be
31 * designed for mixing audio signals. A mixer that actually mixes audio
32 * has multiple input (source) lines and at least one output (target) line.
33 * The former are often instances of classes that implement
34 * <code>{@link SourceDataLine}</code>,
35 * and the latter, <code>{@link TargetDataLine}</code>. <code>{@link Port}</code>
36 * objects, too, are either source lines or target lines.
37 * A mixer can accept prerecorded, loopable sound as input, by having
38 * some of its source lines be instances of objects that implement the
39 * <code>{@link Clip}</code> interface.
40 * <p>
41 * Through methods of the <code>Line</code> interface, which <code>Mixer</code> extends,
42 * a mixer might provide a set of controls that are global to the mixer. For example,
43 * the mixer can have a master gain control. These global controls are distinct
44 * from the controls belonging to each of the mixer's individual lines.
45 * <p>
46 * Some mixers, especially
47 * those with internal digital mixing capabilities, may provide
48 * additional capabilities by implementing the <code>DataLine</code> interface.
49 * <p>
50 * A mixer can support synchronization of its lines. When one line in
51 * a synchronized group is started or stopped, the other lines in the group
52 * automatically start or stop simultaneously with the explicitly affected one.
53 *
54 * @author Kara Kytle
55 * @since 1.3
56 */
57 public interface Mixer extends Line {
58
59 /**
60 * Obtains information about this mixer, including the product's name,
61 * version, vendor, etc.
62 * @return a mixer info object that describes this mixer
63 * @see Mixer.Info
64 */
65 public Info getMixerInfo();
66
67
68 /**
69 * Obtains information about the set of source lines supported
70 * by this mixer.
71 * Some source lines may only be available when this mixer is open.
72 * @return array of <code>Line.Info</code> objects representing source lines
73 * for this mixer. If no source lines are supported,
74 * an array of length 0 is returned.
75 */
76 public Line.Info[] getSourceLineInfo();
77
78 /**
79 * Obtains information about the set of target lines supported
80 * by this mixer.
81 * Some target lines may only be available when this mixer is open.
82 * @return array of <code>Line.Info</code> objects representing target lines
83 * for this mixer. If no target lines are supported,
84 * an array of length 0 is returned.
85 */
86 public Line.Info[] getTargetLineInfo();
87
88
89 /**
90 * Obtains information about source lines of a particular type supported
91 * by the mixer.
92 * Some source lines may only be available when this mixer is open.
93 * @param info a <code>Line.Info</code> object describing lines about which information
94 * is queried
95 * @return an array of <code>Line.Info</code> objects describing source lines matching
96 * the type requested. If no matching source lines are supported, an array of length 0
97 * is returned.
98 */
99 public Line.Info[] getSourceLineInfo(Line.Info info);
100
101
102 /**
103 * Obtains information about target lines of a particular type supported
104 * by the mixer.
105 * Some target lines may only be available when this mixer is open.
106 * @param info a <code>Line.Info</code> object describing lines about which information
107 * is queried
108 * @return an array of <code>Line.Info</code> objects describing target lines matching
109 * the type requested. If no matching target lines are supported, an array of length 0
110 * is returned.
111 */
112 public Line.Info[] getTargetLineInfo(Line.Info info);
113
114
115 /**
116 * Indicates whether the mixer supports a line (or lines) that match
117 * the specified <code>Line.Info</code> object.
118 * Some lines may only be supported when this mixer is open.
119 * @param info describes the line for which support is queried
120 * @return <code>true</code> if at least one matching line is
121 * supported, <code>false</code> otherwise
122 */
123 public boolean isLineSupported(Line.Info info);
124
125 /**
126 * Obtains a line that is available for use and that matches the description
127 * in the specified <code>Line.Info</code> object.
128 *
129 * <p>If a <code>DataLine</code> is requested, and <code>info</code>
130 * is an instance of <code>DataLine.Info</code> specifying at
131 * least one fully qualified audio format, the last one
132 * will be used as the default format of the returned
133 * <code>DataLine</code>.
134 *
135 * @param info describes the desired line
136 * @return a line that is available for use and that matches the description
137 * in the specified {@code Line.Info} object
138 * @throws LineUnavailableException if a matching line
139 * is not available due to resource restrictions
140 * @throws IllegalArgumentException if this mixer does
141 * not support any lines matching the description
142 * @throws SecurityException if a matching line
143 * is not available due to security restrictions
144 */
145 public Line getLine(Line.Info info) throws LineUnavailableException;
146
147 //$$fb 2002-04-12: fix for 4667258: behavior of Mixer.getMaxLines(Line.Info) method doesn't match the spec
148 /**
149 * Obtains the approximate maximum number of lines of the requested type that can be open
150 * simultaneously on the mixer.
151 *
152 * Certain types of mixers do not have a hard bound and may allow opening more lines.
153 * Since certain lines are a shared resource, a mixer may not be able to open the maximum
154 * number of lines if another process has opened lines of this mixer.
155 *
156 * The requested type is any line that matches the description in
157 * the provided <code>Line.Info</code> object. For example, if the info
158 * object represents a speaker
159 * port, and the mixer supports exactly one speaker port, this method
160 * should return 1. If the info object represents a source data line
161 * and the mixer supports the use of 32 source data lines simultaneously,
162 * the return value should be 32.
163 * If there is no limit, this function returns <code>AudioSystem.NOT_SPECIFIED</code>.
164 * @param info a <code>Line.Info</code> that describes the line for which
165 * the number of supported instances is queried
166 * @return the maximum number of matching lines supported, or <code>AudioSystem.NOT_SPECIFIED</code>
167 */
168 public int getMaxLines(Line.Info info);
169
170
171 /**
172 * Obtains the set of all source lines currently open to this mixer.
173 *
174 * @return the source lines currently open to the mixer.
175 * If no source lines are currently open to this mixer, an
176 * array of length 0 is returned.
177 * @throws SecurityException if the matching lines
178 * are not available due to security restrictions
179 */
180 public Line[] getSourceLines();
181
182 /**
183 * Obtains the set of all target lines currently open from this mixer.
184 *
185 * @return target lines currently open from the mixer.
186 * If no target lines are currently open from this mixer, an
187 * array of length 0 is returned.
188 * @throws SecurityException if the matching lines
189 * are not available due to security restrictions
190 */
191 public Line[] getTargetLines();
192
193 /**
194 * Synchronizes two or more lines. Any subsequent command that starts or stops
195 * audio playback or capture for one of these lines will exert the
196 * same effect on the other lines in the group, so that they start or stop playing or
197 * capturing data simultaneously.
198 *
199 * @param lines the lines that should be synchronized
200 * @param maintainSync <code>true</code> if the synchronization
201 * must be precisely maintained (i.e., the synchronization must be sample-accurate)
202 * at all times during operation of the lines , or <code>false</code>
203 * if precise synchronization is required only during start and stop operations
204 *
205 * @throws IllegalArgumentException if the lines cannot be synchronized.
206 * This may occur if the lines are of different types or have different
207 * formats for which this mixer does not support synchronization, or if
208 * all lines specified do not belong to this mixer.
209 */
210 public void synchronize(Line[] lines, boolean maintainSync);
211
212 /**
213 * Releases synchronization for the specified lines. The array must
214 * be identical to one for which synchronization has already been
215 * established; otherwise an exception may be thrown. However, <code>null</code>
216 * may be specified, in which case all currently synchronized lines that belong
217 * to this mixer are unsynchronized.
218 * @param lines the synchronized lines for which synchronization should be
219 * released, or <code>null</code> for all this mixer's synchronized lines
220 *
221 * @throws IllegalArgumentException if the lines cannot be unsynchronized.
222 * This may occur if the argument specified does not exactly match a set
223 * of lines for which synchronization has already been established.
224 */
225 public void unsynchronize(Line[] lines);
226
227
228 /**
229 * Reports whether this mixer supports synchronization of the specified set of lines.
230 *
231 * @param lines the set of lines for which synchronization support is queried
232 * @param maintainSync <code>true</code> if the synchronization
233 * must be precisely maintained (i.e., the synchronization must be sample-accurate)
234 * at all times during operation of the lines , or <code>false</code>
235 * if precise synchronization is required only during start and stop operations
236 *
237 * @return <code>true</code> if the lines can be synchronized, <code>false</code>
238 * otherwise
239 */
240 public boolean isSynchronizationSupported(Line[] lines, boolean maintainSync);
241
242
243 /**
244 * The <code>Mixer.Info</code> class represents information about an audio mixer,
245 * including the product's name, version, and vendor, along with a textual
246 * description. This information may be retrieved through the
247 * {@link Mixer#getMixerInfo() getMixerInfo}
248 * method of the <code>Mixer</code> interface.
249 *
250 * @author Kara Kytle
251 * @since 1.3
252 */
253 public static class Info {
254
255 /**
256 * Mixer name.
257 */
258 private final String name;
259
260 /**
261 * Mixer vendor.
262 */
263 private final String vendor;
264
265 /**
266 * Mixer description.
267 */
268 private final String description;
269
270 /**
271 * Mixer version.
272 */
273 private final String version;
274
275 /**
276 * Constructs a mixer's info object, passing it the given
277 * textual information.
278 * @param name the name of the mixer
279 * @param vendor the company who manufactures or creates the hardware
280 * or software mixer
281 * @param description descriptive text about the mixer
282 * @param version version information for the mixer
283 */
284 protected Info(String name, String vendor, String description, String version) {
285
286 this.name = name;
287 this.vendor = vendor;
288 this.description = description;
289 this.version = version;
290 }
291
292
293 /**
294 * Indicates whether two info objects are equal, returning <code>true</code> if
295 * they are identical.
296 * @param obj the reference object with which to compare this info
297 * object
298 * @return <code>true</code> if this info object is the same as the
299 * <code>obj</code> argument; <code>false</code> otherwise
300 */
301 public final boolean equals(Object obj) {
302 return super.equals(obj);
303 }
304
305 /**
306 * Finalizes the hashcode method.
307 *
308 * @return the hashcode for this object
309 */
310 public final int hashCode() {
311 return super.hashCode();
312 }
313
314 /**
315 * Obtains the name of the mixer.
316 * @return a string that names the mixer
317 */
318 public final String getName() {
319 return name;
320 }
321
322 /**
323 * Obtains the vendor of the mixer.
324 * @return a string that names the mixer's vendor
325 */
326 public final String getVendor() {
327 return vendor;
328 }
329
330 /**
331 * Obtains the description of the mixer.
332 * @return a textual description of the mixer
333 */
334 public final String getDescription() {
335 return description;
336 }
337
338 /**
339 * Obtains the version of the mixer.
340 * @return textual version information for the mixer
341 */
342 public final String getVersion() {
343 return version;
344 }
345
346 /**
347 * Provides a string representation of the mixer info.
348 * @return a string describing the info object
349 */
350 public final String toString() {
351 return (name + ", version " + version);
352 }
353 } // class Info
354 }