1 /*
2 * Copyright (c) 1999, 2017, 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
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20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
25
26 package javax.sound.sampled;
27
28 import java.util.Collections;
29 import java.util.HashMap;
30 import java.util.Map;
31 import java.util.Objects;
32
33 /**
34 * {@code AudioFormat} is the class that specifies a particular arrangement of
35 * data in a sound stream. By examining the information stored in the audio
36 * format, you can discover how to interpret the bits in the binary sound data.
37 * <p>
38 * Every data line has an audio format associated with its data stream. The
39 * audio format of a source (playback) data line indicates what kind of data the
40 * data line expects to receive for output. For a target (capture) data line,
41 * the audio format specifies the kind of the data that can be read from the
42 * line.
43 * Sound files also have audio formats, of course. The {@link AudioFileFormat}
44 * class encapsulates an {@code AudioFormat} in addition to other, file-specific
45 * information. Similarly, an {@link AudioInputStream} has an
46 * {@code AudioFormat}.
47 * <p>
48 * The {@code AudioFormat} class accommodates a number of common sound-file
49 * encoding techniques, including pulse-code modulation (PCM), mu-law encoding,
50 * and a-law encoding. These encoding techniques are predefined, but service
51 * providers can create new encoding types. The encoding that a specific format
52 * uses is named by its {@code encoding} field.
53 * <p>
54 * In addition to the encoding, the audio format includes other properties that
55 * further specify the exact arrangement of the data. These include the number
56 * of channels, sample rate, sample size, byte order, frame rate, and frame
57 * size. Sounds may have different numbers of audio channels: one for mono, two
58 * for stereo. The sample rate measures how many "snapshots" (samples) of the
59 * sound pressure are taken per second, per channel. (If the sound is stereo
60 * rather than mono, two samples are actually measured at each instant of time:
61 * one for the left channel, and another for the right channel; however, the
62 * sample rate still measures the number per channel, so the rate is the same
63 * regardless of the number of channels. This is the standard use of the term.)
64 * The sample size indicates how many bits are used to store each snapshot; 8
65 * and 16 are typical values. For 16-bit samples (or any other sample size
66 * larger than a byte), byte order is important; the bytes in each sample are
67 * arranged in either the "little-endian" or "big-endian" style. For encodings
68 * like PCM, a frame consists of the set of samples for all channels at a given
69 * point in time, and so the size of a frame (in bytes) is always equal to the
70 * size of a sample (in bytes) times the number of channels. However, with some
71 * other sorts of encodings a frame can contain a bundle of compressed data for
72 * a whole series of samples, as well as additional, non-sample data. For such
73 * encodings, the sample rate and sample size refer to the data after it is
74 * decoded into PCM, and so they are completely different from the frame rate
75 * and frame size.
76 * <p>
77 * An {@code AudioFormat} object can include a set of properties. A property is
78 * a pair of key and value: the key is of type {@code String}, the associated
79 * property value is an arbitrary object. Properties specify additional format
80 * specifications, like the bit rate for compressed formats. Properties are
81 * mainly used as a means to transport additional information of the audio
82 * format to and from the service providers. Therefore, properties are ignored
83 * in the {@link #matches(AudioFormat)} method. However, methods which rely on
84 * the installed service providers, like
85 * {@link AudioSystem#isConversionSupported (AudioFormat, AudioFormat)
86 * isConversionSupported} may consider properties, depending on the respective
87 * service provider implementation.
88 * <p>
89 * The following table lists some common properties which service providers
90 * should use, if applicable:
91 *
92 * <table class="striped">
93 * <caption>Audio Format Properties</caption>
94 * <thead>
95 * <tr>
96 * <th>Property key</th>
97 * <th>Value type</th>
98 * <th>Description</th>
99 * </tr>
100 * </thead>
101 * <tbody>
102 * <tr>
103 * <td>"bitrate"</td>
104 * <td>{@link java.lang.Integer Integer}</td>
105 * <td>average bit rate in bits per second</td>
106 * </tr>
107 * <tr>
108 * <td>"vbr"</td>
109 * <td>{@link java.lang.Boolean Boolean}</td>
110 * <td>{@code true}, if the file is encoded in variable bit
111 * rate (VBR)</td>
112 * </tr>
113 * <tr>
114 * <td>"quality"</td>
115 * <td>{@link java.lang.Integer Integer}</td>
116 * <td>encoding/conversion quality, 1..100</td>
117 * </tr>
118 * </tbody>
119 * </table>
120 * <p>
121 * Vendors of service providers (plugins) are encouraged to seek information
122 * about other already established properties in third party plugins, and follow
123 * the same conventions.
124 *
125 * @author Kara Kytle
126 * @author Florian Bomers
127 * @see DataLine#getFormat
128 * @see AudioInputStream#getFormat
129 * @see AudioFileFormat
130 * @see javax.sound.sampled.spi.FormatConversionProvider
131 * @since 1.3
132 */
133 public class AudioFormat {
134
135 /**
136 * The audio encoding technique used by this format.
137 */
138 protected Encoding encoding;
139
140 /**
141 * The number of samples played or recorded per second, for sounds that have
142 * this format.
143 */
144 protected float sampleRate;
145
146 /**
147 * The number of bits in each sample of a sound that has this format.
148 */
149 protected int sampleSizeInBits;
150
151 /**
152 * The number of audio channels in this format (1 for mono, 2 for stereo).
153 */
154 protected int channels;
155
156 /**
157 * The number of bytes in each frame of a sound that has this format.
158 */
159 protected int frameSize;
160
161 /**
162 * The number of frames played or recorded per second, for sounds that have
163 * this format.
164 */
165 protected float frameRate;
166
167 /**
168 * Indicates whether the audio data is stored in big-endian or little-endian
169 * order.
170 */
171 protected boolean bigEndian;
172
173 /**
174 * The set of properties.
175 */
176 private HashMap<String, Object> properties;
177
178 /**
179 * Constructs an {@code AudioFormat} with the given parameters. The encoding
180 * specifies the convention used to represent the data. The other parameters
181 * are further explained in the {@link AudioFormat class description}.
182 *
183 * @param encoding the audio encoding technique
184 * @param sampleRate the number of samples per second
185 * @param sampleSizeInBits the number of bits in each sample
186 * @param channels the number of channels (1 for mono, 2 for stereo,
187 * and so on)
188 * @param frameSize the number of bytes in each frame
189 * @param frameRate the number of frames per second
190 * @param bigEndian indicates whether the data for a single sample is
191 * stored in big-endian byte order ({@code false} means
192 * little-endian)
193 */
194 public AudioFormat(Encoding encoding, float sampleRate, int sampleSizeInBits,
195 int channels, int frameSize, float frameRate, boolean bigEndian) {
196
197 this.encoding = encoding;
198 this.sampleRate = sampleRate;
199 this.sampleSizeInBits = sampleSizeInBits;
200 this.channels = channels;
201 this.frameSize = frameSize;
202 this.frameRate = frameRate;
203 this.bigEndian = bigEndian;
204 this.properties = null;
205 }
206
207 /**
208 * Constructs an {@code AudioFormat} with the given parameters. The encoding
209 * specifies the convention used to represent the data. The other parameters
210 * are further explained in the {@link AudioFormat class description}.
211 *
212 * @param encoding the audio encoding technique
213 * @param sampleRate the number of samples per second
214 * @param sampleSizeInBits the number of bits in each sample
215 * @param channels the number of channels (1 for mono, 2 for stereo, and so
216 * on)
217 * @param frameSize the number of bytes in each frame
218 * @param frameRate the number of frames per second
219 * @param bigEndian indicates whether the data for a single sample is
220 * stored in big-endian byte order ({@code false} means little-endian)
221 * @param properties a {@code Map<String, Object>} object containing format
222 * properties
223 * @since 1.5
224 */
225 public AudioFormat(Encoding encoding, float sampleRate,
226 int sampleSizeInBits, int channels,
227 int frameSize, float frameRate,
228 boolean bigEndian, Map<String, Object> properties) {
229 this(encoding, sampleRate, sampleSizeInBits, channels,
230 frameSize, frameRate, bigEndian);
231 this.properties = new HashMap<>(properties);
232 }
233
234 /**
235 * Constructs an {@code AudioFormat} with a linear PCM encoding and the
236 * given parameters. The frame size is set to the number of bytes required
237 * to contain one sample from each channel, and the frame rate is set to the
238 * sample rate.
239 *
240 * @param sampleRate the number of samples per second
241 * @param sampleSizeInBits the number of bits in each sample
242 * @param channels the number of channels (1 for mono, 2 for stereo, and so
243 * on)
244 * @param signed indicates whether the data is signed or unsigned
245 * @param bigEndian indicates whether the data for a single sample is
246 * stored in big-endian byte order ({@code false} means
247 * little-endian)
248 */
249 public AudioFormat(float sampleRate, int sampleSizeInBits,
250 int channels, boolean signed, boolean bigEndian) {
251
252 this((signed == true ? Encoding.PCM_SIGNED : Encoding.PCM_UNSIGNED),
253 sampleRate,
254 sampleSizeInBits,
255 channels,
256 (channels == AudioSystem.NOT_SPECIFIED || sampleSizeInBits == AudioSystem.NOT_SPECIFIED)?
257 AudioSystem.NOT_SPECIFIED:
258 ((sampleSizeInBits + 7) / 8) * channels,
259 sampleRate,
260 bigEndian);
261 }
262
263 /**
264 * Obtains the type of encoding for sounds in this format.
265 *
266 * @return the encoding type
267 * @see Encoding#PCM_SIGNED
268 * @see Encoding#PCM_UNSIGNED
269 * @see Encoding#ULAW
270 * @see Encoding#ALAW
271 */
272 public Encoding getEncoding() {
273
274 return encoding;
275 }
276
277 /**
278 * Obtains the sample rate. For compressed formats, the return value is the
279 * sample rate of the uncompressed audio data. When this AudioFormat is used
280 * for queries (e.g. {@link AudioSystem#isConversionSupported(AudioFormat,
281 * AudioFormat) AudioSystem.isConversionSupported}) or capabilities (e.g.
282 * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a sample rate
283 * of {@code AudioSystem.NOT_SPECIFIED} means that any sample rate is
284 * acceptable. {@code AudioSystem.NOT_SPECIFIED} is also returned when the
285 * sample rate is not defined for this audio format.
286 *
287 * @return the number of samples per second, or
288 * {@code AudioSystem.NOT_SPECIFIED}
289 * @see #getFrameRate()
290 * @see AudioSystem#NOT_SPECIFIED
291 */
292 public float getSampleRate() {
293
294 return sampleRate;
295 }
296
297 /**
298 * Obtains the size of a sample. For compressed formats, the return value is
299 * the sample size of the uncompressed audio data. When this AudioFormat is
300 * used for queries (e.g. {@link AudioSystem#isConversionSupported(
301 * AudioFormat,AudioFormat) AudioSystem.isConversionSupported}) or
302 * capabilities (e.g.
303 * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a sample size
304 * of {@code AudioSystem.NOT_SPECIFIED} means that any sample size is
305 * acceptable. {@code AudioSystem.NOT_SPECIFIED} is also returned when the
306 * sample size is not defined for this audio format.
307 *
308 * @return the number of bits in each sample, or
309 * {@code AudioSystem.NOT_SPECIFIED}
310 * @see #getFrameSize()
311 * @see AudioSystem#NOT_SPECIFIED
312 */
313 public int getSampleSizeInBits() {
314
315 return sampleSizeInBits;
316 }
317
318 /**
319 * Obtains the number of channels. When this AudioFormat is used for queries
320 * (e.g. {@link AudioSystem#isConversionSupported(AudioFormat, AudioFormat)
321 * AudioSystem.isConversionSupported}) or capabilities (e.g.
322 * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a return
323 * value of {@code AudioSystem.NOT_SPECIFIED} means that any (positive)
324 * number of channels is acceptable.
325 *
326 * @return The number of channels (1 for mono, 2 for stereo, etc.), or
327 * {@code AudioSystem.NOT_SPECIFIED}
328 * @see AudioSystem#NOT_SPECIFIED
329 */
330 public int getChannels() {
331
332 return channels;
333 }
334
335 /**
336 * Obtains the frame size in bytes. When this AudioFormat is used for
337 * queries (e.g. {@link AudioSystem#isConversionSupported(AudioFormat,
338 * AudioFormat) AudioSystem.isConversionSupported}) or capabilities (e.g.
339 * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a frame size
340 * of {@code AudioSystem.NOT_SPECIFIED} means that any frame size is
341 * acceptable. {@code AudioSystem.NOT_SPECIFIED} is also returned when the
342 * frame size is not defined for this audio format.
343 *
344 * @return the number of bytes per frame, or
345 * {@code AudioSystem.NOT_SPECIFIED}
346 * @see #getSampleSizeInBits()
347 * @see AudioSystem#NOT_SPECIFIED
348 */
349 public int getFrameSize() {
350
351 return frameSize;
352 }
353
354 /**
355 * Obtains the frame rate in frames per second. When this AudioFormat is
356 * used for queries (e.g. {@link AudioSystem#isConversionSupported(
357 * AudioFormat,AudioFormat) AudioSystem.isConversionSupported}) or
358 * capabilities (e.g.
359 * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a frame rate
360 * of {@code AudioSystem.NOT_SPECIFIED} means that any frame rate is
361 * acceptable. {@code AudioSystem.NOT_SPECIFIED} is also returned when the
362 * frame rate is not defined for this audio format.
363 *
364 * @return the number of frames per second, or
365 * {@code AudioSystem.NOT_SPECIFIED}
366 * @see #getSampleRate()
367 * @see AudioSystem#NOT_SPECIFIED
368 */
369 public float getFrameRate() {
370
371 return frameRate;
372 }
373
374 /**
375 * Indicates whether the audio data is stored in big-endian or little-endian
376 * byte order. If the sample size is not more than one byte, the return
377 * value is irrelevant.
378 *
379 * @return {@code true} if the data is stored in big-endian byte order,
380 * {@code false} if little-endian
381 */
382 public boolean isBigEndian() {
383
384 return bigEndian;
385 }
386
387 /**
388 * Obtain an unmodifiable map of properties. The concept of properties is
389 * further explained in the {@link AudioFileFormat class description}.
390 *
391 * @return a {@code Map<String, Object>} object containing all properties.
392 * If no properties are recognized, an empty map is returned.
393 * @see #getProperty(String)
394 * @since 1.5
395 */
396 @SuppressWarnings("unchecked") // Cast of result of clone.
397 public Map<String,Object> properties() {
398 Map<String,Object> ret;
399 if (properties == null) {
400 ret = new HashMap<>(0);
401 } else {
402 ret = (Map<String,Object>) (properties.clone());
403 }
404 return Collections.unmodifiableMap(ret);
405 }
406
407 /**
408 * Obtain the property value specified by the key. The concept of properties
409 * is further explained in the {@link AudioFileFormat class description}.
410 * <p>
411 * If the specified property is not defined for a particular file format,
412 * this method returns {@code null}.
413 *
414 * @param key the key of the desired property
415 * @return the value of the property with the specified key, or {@code null}
416 * if the property does not exist
417 * @see #properties()
418 * @since 1.5
419 */
420 public Object getProperty(String key) {
421 if (properties == null) {
422 return null;
423 }
424 return properties.get(key);
425 }
426
427 /**
428 * Indicates whether this format matches the one specified. To match, two
429 * formats must have the same encoding, and consistent values of the number
430 * of channels, sample rate, sample size, frame rate, and frame size. The
431 * values of the property are consistent if they are equal or the specified
432 * format has the property value {@code AudioSystem.NOT_SPECIFIED}. The byte
433 * order (big-endian or little-endian) must be the same if the sample size
434 * is greater than one byte.
435 *
436 * @param format format to test for match
437 * @return {@code true} if this format matches the one specified,
438 * {@code false} otherwise
439 */
440 public boolean matches(AudioFormat format) {
441 if (format.getEncoding().equals(getEncoding())
442 && (format.getChannels() == AudioSystem.NOT_SPECIFIED
443 || format.getChannels() == getChannels())
444 && (format.getSampleRate() == (float)AudioSystem.NOT_SPECIFIED
445 || format.getSampleRate() == getSampleRate())
446 && (format.getSampleSizeInBits() == AudioSystem.NOT_SPECIFIED
447 || format.getSampleSizeInBits() == getSampleSizeInBits())
448 && (format.getFrameRate() == (float)AudioSystem.NOT_SPECIFIED
449 || format.getFrameRate() == getFrameRate())
450 && (format.getFrameSize() == AudioSystem.NOT_SPECIFIED
451 || format.getFrameSize() == getFrameSize())
452 && (getSampleSizeInBits() <= 8
453 || format.isBigEndian() == isBigEndian())) {
454 return true;
455 }
456 return false;
457 }
458
459 /**
460 * Returns a string that describes the format, such as: "PCM SIGNED 22050 Hz
461 * 16 bit mono big-endian". The contents of the string may vary between
462 * implementations of Java Sound.
463 *
464 * @return a string that describes the format parameters
465 */
466 @Override
467 public String toString() {
468 String sEncoding = "";
469 if (getEncoding() != null) {
470 sEncoding = getEncoding().toString() + " ";
471 }
472
473 String sSampleRate;
474 if (getSampleRate() == (float) AudioSystem.NOT_SPECIFIED) {
475 sSampleRate = "unknown sample rate, ";
476 } else {
477 sSampleRate = "" + getSampleRate() + " Hz, ";
478 }
479
480 String sSampleSizeInBits;
481 if (getSampleSizeInBits() == (float) AudioSystem.NOT_SPECIFIED) {
482 sSampleSizeInBits = "unknown bits per sample, ";
483 } else {
484 sSampleSizeInBits = "" + getSampleSizeInBits() + " bit, ";
485 }
486
487 String sChannels;
488 if (getChannels() == 1) {
489 sChannels = "mono, ";
490 } else
491 if (getChannels() == 2) {
492 sChannels = "stereo, ";
493 } else {
494 if (getChannels() == AudioSystem.NOT_SPECIFIED) {
495 sChannels = " unknown number of channels, ";
496 } else {
497 sChannels = ""+getChannels()+" channels, ";
498 }
499 }
500
501 String sFrameSize;
502 if (getFrameSize() == (float) AudioSystem.NOT_SPECIFIED) {
503 sFrameSize = "unknown frame size, ";
504 } else {
505 sFrameSize = "" + getFrameSize()+ " bytes/frame, ";
506 }
507
508 String sFrameRate = "";
509 if (Math.abs(getSampleRate() - getFrameRate()) > 0.00001) {
510 if (getFrameRate() == (float) AudioSystem.NOT_SPECIFIED) {
511 sFrameRate = "unknown frame rate, ";
512 } else {
513 sFrameRate = getFrameRate() + " frames/second, ";
514 }
515 }
516
517 String sEndian = "";
518 if ((getEncoding().equals(Encoding.PCM_SIGNED)
519 || getEncoding().equals(Encoding.PCM_UNSIGNED))
520 && ((getSampleSizeInBits() > 8)
521 || (getSampleSizeInBits() == AudioSystem.NOT_SPECIFIED))) {
522 if (isBigEndian()) {
523 sEndian = "big-endian";
524 } else {
525 sEndian = "little-endian";
526 }
527 }
528
529 return sEncoding
530 + sSampleRate
531 + sSampleSizeInBits
532 + sChannels
533 + sFrameSize
534 + sFrameRate
535 + sEndian;
536
537 }
538
539 /**
540 * The {@code Encoding} class names the specific type of data representation
541 * used for an audio stream. The encoding includes aspects of the sound
542 * format other than the number of channels, sample rate, sample size, frame
543 * rate, frame size, and byte order.
544 * <p>
545 * One ubiquitous type of audio encoding is pulse-code modulation (PCM),
546 * which is simply a linear (proportional) representation of the sound
547 * waveform. With PCM, the number stored in each sample is proportional to
548 * the instantaneous amplitude of the sound pressure at that point in time.
549 * The numbers may be signed or unsigned integers or floats. Besides PCM,
550 * other encodings include mu-law and a-law, which are nonlinear mappings of
551 * the sound amplitude that are often used for recording speech.
552 * <p>
553 * You can use a predefined encoding by referring to one of the static
554 * objects created by this class, such as PCM_SIGNED or PCM_UNSIGNED.
555 * Service providers can create new encodings, such as compressed audio
556 * formats, and make these available through the {@link AudioSystem} class.
557 * <p>
558 * The {@code Encoding} class is static, so that all {@code AudioFormat}
559 * objects that have the same encoding will refer to the same object (rather
560 * than different instances of the same class). This allows matches to be
561 * made by checking that two format's encodings are equal.
562 *
563 * @author Kara Kytle
564 * @see AudioFormat
565 * @see javax.sound.sampled.spi.FormatConversionProvider
566 * @since 1.3
567 */
568 public static class Encoding {
569
570 /**
571 * Specifies signed, linear PCM data.
572 */
573 public static final Encoding PCM_SIGNED = new Encoding("PCM_SIGNED");
574
575 /**
576 * Specifies unsigned, linear PCM data.
577 */
578 public static final Encoding PCM_UNSIGNED = new Encoding("PCM_UNSIGNED");
579
580 /**
581 * Specifies floating-point PCM data.
582 *
583 * @since 1.7
584 */
585 public static final Encoding PCM_FLOAT = new Encoding("PCM_FLOAT");
586
587 /**
588 * Specifies u-law encoded data.
589 */
590 public static final Encoding ULAW = new Encoding("ULAW");
591
592 /**
593 * Specifies a-law encoded data.
594 */
595 public static final Encoding ALAW = new Encoding("ALAW");
596
597 /**
598 * Encoding name.
599 */
600 private final String name;
601
602 /**
603 * Constructs a new encoding.
604 *
605 * @param name the name of the new type of encoding
606 */
607 public Encoding(final String name) {
608 this.name = name;
609 }
610
611 /**
612 * Finalizes the equals method.
613 */
614 @Override
615 public final boolean equals(final Object obj) {
616 if (this == obj) {
617 return true;
618 }
619 if (!(obj instanceof Encoding)) {
620 return false;
621 }
622 return Objects.equals(name, ((Encoding) obj).name);
623 }
624
625 /**
626 * Finalizes the hashCode method.
627 */
628 @Override
629 public final int hashCode() {
630 return name != null ? name.hashCode() : 0;
631 }
632
633 /**
634 * Provides the {@code String} representation of the encoding. This
635 * {@code String} is the same name that was passed to the constructor.
636 * For the predefined encodings, the name is similar to the encoding's
637 * variable (field) name. For example, {@code PCM_SIGNED.toString()}
638 * returns the name "PCM_SIGNED".
639 *
640 * @return the encoding name
641 */
642 @Override
643 public final String toString() {
644 return name;
645 }
646 }
647 }