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 import java.io.InputStream;
29 import java.io.PushbackInputStream;
30 import java.io.IOException;
31
32
33 /**
34 * An audio input stream is an input stream with a specified audio format and
35 * length. The length is expressed in sample frames, not bytes.
36 * Several methods are provided for reading a certain number of bytes from
37 * the stream, or an unspecified number of bytes.
38 * The audio input stream keeps track of the last byte that was read.
39 * You can skip over an arbitrary number of bytes to get to a later position
40 * for reading. An audio input stream may support marks. When you set a mark,
41 * the current position is remembered so that you can return to it later.
42 * <p>
43 * The <code>AudioSystem</code> class includes many methods that manipulate
44 * <code>AudioInputStream</code> objects.
45 * For example, the methods let you:
46 * <ul>
47 * <li> obtain an
48 * audio input stream from an external audio file, stream, or URL
49 * <li> write an external file from an audio input stream
50 * <li> convert an audio input stream to a different audio format
51 * </ul>
52 *
53 * @author David Rivas
54 * @author Kara Kytle
55 * @author Florian Bomers
56 *
57 * @see AudioSystem
58 * @see Clip#open(AudioInputStream) Clip.open(AudioInputStream)
59 * @since 1.3
60 */
61 public class AudioInputStream extends InputStream {
62
63 /**
64 * The <code>InputStream</code> from which this <code>AudioInputStream</code>
65 * object was constructed.
66 */
67 private InputStream stream;
68
69 /**
70 * The format of the audio data contained in the stream.
71 */
72 protected AudioFormat format;
73
74 /**
75 * This stream's length, in sample frames.
76 */
77 protected long frameLength;
78
79 /**
80 * The size of each frame, in bytes.
81 */
82 protected int frameSize;
83
84 /**
85 * The current position in this stream, in sample frames (zero-based).
86 */
87 protected long framePos;
88
89 /**
90 * The position where a mark was set.
91 */
92 private long markpos;
93
94 /**
95 * When the underlying stream could only return
96 * a non-integral number of frames, store
97 * the remainder in a temporary buffer
98 */
99 private byte[] pushBackBuffer = null;
100
101 /**
102 * number of valid bytes in the pushBackBuffer
103 */
104 private int pushBackLen = 0;
105
106 /**
107 * MarkBuffer at mark position
108 */
109 private byte[] markPushBackBuffer = null;
110
111 /**
112 * number of valid bytes in the markPushBackBuffer
113 */
114 private int markPushBackLen = 0;
115
116
117 /**
118 * Constructs an audio input stream that has the requested format and length in sample frames,
119 * using audio data from the specified input stream.
120 * @param stream the stream on which this <code>AudioInputStream</code>
121 * object is based
122 * @param format the format of this stream's audio data
123 * @param length the length in sample frames of the data in this stream
124 */
125 public AudioInputStream(InputStream stream, AudioFormat format, long length) {
126
127 super();
128
129 this.format = format;
130 this.frameLength = length;
131 this.frameSize = format.getFrameSize();
132
133 // any frameSize that is not well-defined will
134 // cause that this stream will be read in bytes
135 if( this.frameSize == AudioSystem.NOT_SPECIFIED || frameSize <= 0) {
136 this.frameSize = 1;
137 }
138
139 this.stream = stream;
140 framePos = 0;
141 markpos = 0;
142 }
143
144
145 /**
146 * Constructs an audio input stream that reads its data from the target
147 * data line indicated. The format of the stream is the same as that of
148 * the target data line, and the length is AudioSystem#NOT_SPECIFIED.
149 * @param line the target data line from which this stream obtains its data.
150 * @see AudioSystem#NOT_SPECIFIED
151 */
152 public AudioInputStream(TargetDataLine line) {
153
154 TargetDataLineInputStream tstream = new TargetDataLineInputStream(line);
155 format = line.getFormat();
156 frameLength = AudioSystem.NOT_SPECIFIED;
157 frameSize = format.getFrameSize();
158
159 if( frameSize == AudioSystem.NOT_SPECIFIED || frameSize <= 0) {
160 frameSize = 1;
161 }
162 this.stream = tstream;
163 framePos = 0;
164 markpos = 0;
165 }
166
167
168 /**
169 * Obtains the audio format of the sound data in this audio input stream.
170 * @return an audio format object describing this stream's format
171 */
172 public AudioFormat getFormat() {
173 return format;
174 }
175
176
177 /**
178 * Obtains the length of the stream, expressed in sample frames rather than bytes.
179 * @return the length in sample frames
180 */
181 public long getFrameLength() {
182 return frameLength;
183 }
184
185
186 /**
187 * Reads the next byte of data from the audio input stream. The audio input
188 * stream's frame size must be one byte, or an <code>IOException</code>
189 * will be thrown.
190 *
191 * @return the next byte of data, or -1 if the end of the stream is reached
192 * @throws IOException if an input or output error occurs
193 * @see #read(byte[], int, int)
194 * @see #read(byte[])
195 * @see #available
196 */
197 public int read() throws IOException {
198 if( frameSize != 1 ) {
199 throw new IOException("cannot read a single byte if frame size > 1");
200 }
201
202 byte[] data = new byte[1];
203 int temp = read(data);
204 if (temp <= 0) {
205 // we have a weird situation if read(byte[]) returns 0!
206 return -1;
207 }
208 return data[0] & 0xFF;
209 }
210
211
212 /**
213 * Reads some number of bytes from the audio input stream and stores them into
214 * the buffer array <code>b</code>. The number of bytes actually read is
215 * returned as an integer. This method blocks until input data is
216 * available, the end of the stream is detected, or an exception is thrown.
217 * <p>This method will always read an integral number of frames.
218 * If the length of the array is not an integral number
219 * of frames, a maximum of <code>b.length - (b.length % frameSize)
220 * </code> bytes will be read.
221 *
222 * @param b the buffer into which the data is read
223 * @return the total number of bytes read into the buffer, or -1 if there
224 * is no more data because the end of the stream has been reached
225 * @throws IOException if an input or output error occurs
226 * @see #read(byte[], int, int)
227 * @see #read()
228 * @see #available
229 */
230 public int read(byte[] b) throws IOException {
231 return read(b,0,b.length);
232 }
233
234
235 /**
236 * Reads up to a specified maximum number of bytes of data from the audio
237 * stream, putting them into the given byte array.
238 * <p>This method will always read an integral number of frames.
239 * If <code>len</code> does not specify an integral number
240 * of frames, a maximum of <code>len - (len % frameSize)
241 * </code> bytes will be read.
242 *
243 * @param b the buffer into which the data is read
244 * @param off the offset, from the beginning of array <code>b</code>, at which
245 * the data will be written
246 * @param len the maximum number of bytes to read
247 * @return the total number of bytes read into the buffer, or -1 if there
248 * is no more data because the end of the stream has been reached
249 * @throws IOException if an input or output error occurs
250 * @see #read(byte[])
251 * @see #read()
252 * @see #skip
253 * @see #available
254 */
255 public int read(byte[] b, int off, int len) throws IOException {
256
257 // make sure we don't read fractions of a frame.
258 if( (len%frameSize) != 0 ) {
259 len -= (len%frameSize);
260 if (len == 0) {
261 return 0;
262 }
263 }
264
265 if( frameLength != AudioSystem.NOT_SPECIFIED ) {
266 if( framePos >= frameLength ) {
267 return -1;
268 } else {
269
270 // don't try to read beyond our own set length in frames
271 if( (len/frameSize) > (frameLength-framePos) ) {
272 len = (int) (frameLength-framePos) * frameSize;
273 }
274 }
275 }
276
277 int bytesRead = 0;
278 int thisOff = off;
279
280 // if we've bytes left from last call to read(),
281 // use them first
282 if (pushBackLen > 0 && len >= pushBackLen) {
283 System.arraycopy(pushBackBuffer, 0,
284 b, off, pushBackLen);
285 thisOff += pushBackLen;
286 len -= pushBackLen;
287 bytesRead += pushBackLen;
288 pushBackLen = 0;
289 }
290
291 int thisBytesRead = stream.read(b, thisOff, len);
292 if (thisBytesRead == -1) {
293 return -1;
294 }
295 if (thisBytesRead > 0) {
296 bytesRead += thisBytesRead;
297 }
298 if (bytesRead > 0) {
299 pushBackLen = bytesRead % frameSize;
300 if (pushBackLen > 0) {
301 // copy everything we got from the beginning of the frame
302 // to our pushback buffer
303 if (pushBackBuffer == null) {
304 pushBackBuffer = new byte[frameSize];
305 }
306 System.arraycopy(b, off + bytesRead - pushBackLen,
307 pushBackBuffer, 0, pushBackLen);
308 bytesRead -= pushBackLen;
309 }
310 // make sure to update our framePos
311 framePos += bytesRead/frameSize;
312 }
313 return bytesRead;
314 }
315
316
317 /**
318 * Skips over and discards a specified number of bytes from this
319 * audio input stream.
320 * @param n the requested number of bytes to be skipped
321 * @return the actual number of bytes skipped
322 * @throws IOException if an input or output error occurs
323 * @see #read
324 * @see #available
325 */
326 public long skip(long n) throws IOException {
327
328 // make sure not to skip fractional frames
329 if( (n%frameSize) != 0 ) {
330 n -= (n%frameSize);
331 }
332
333 if( frameLength != AudioSystem.NOT_SPECIFIED ) {
334 // don't skip more than our set length in frames.
335 if( (n/frameSize) > (frameLength-framePos) ) {
336 n = (frameLength-framePos) * frameSize;
337 }
338 }
339 long temp = stream.skip(n);
340
341 // if no error, update our position.
342 if( temp%frameSize != 0 ) {
343
344 // Throw an IOException if we've skipped a fractional number of frames
345 throw new IOException("Could not skip an integer number of frames.");
346 }
347 if( temp >= 0 ) {
348 framePos += temp/frameSize;
349 }
350 return temp;
351
352 }
353
354
355 /**
356 * Returns the maximum number of bytes that can be read (or skipped over) from this
357 * audio input stream without blocking. This limit applies only to the next invocation of
358 * a <code>read</code> or <code>skip</code> method for this audio input stream; the limit
359 * can vary each time these methods are invoked.
360 * Depending on the underlying stream,an IOException may be thrown if this
361 * stream is closed.
362 * @return the number of bytes that can be read from this audio input stream without blocking
363 * @throws IOException if an input or output error occurs
364 * @see #read(byte[], int, int)
365 * @see #read(byte[])
366 * @see #read()
367 * @see #skip
368 */
369 public int available() throws IOException {
370
371 int temp = stream.available();
372
373 // don't return greater than our set length in frames
374 if( (frameLength != AudioSystem.NOT_SPECIFIED) && ( (temp/frameSize) > (frameLength-framePos)) ) {
375 return (int) (frameLength-framePos) * frameSize;
376 } else {
377 return temp;
378 }
379 }
380
381
382 /**
383 * Closes this audio input stream and releases any system resources associated
384 * with the stream.
385 * @throws IOException if an input or output error occurs
386 */
387 public void close() throws IOException {
388 stream.close();
389 }
390
391
392 /**
393 * Marks the current position in this audio input stream.
394 * @param readlimit the maximum number of bytes that can be read before
395 * the mark position becomes invalid.
396 * @see #reset
397 * @see #markSupported
398 */
399
400 public void mark(int readlimit) {
401
402 stream.mark(readlimit);
403 if (markSupported()) {
404 markpos = framePos;
405 // remember the pushback buffer
406 markPushBackLen = pushBackLen;
407 if (markPushBackLen > 0) {
408 if (markPushBackBuffer == null) {
409 markPushBackBuffer = new byte[frameSize];
410 }
411 System.arraycopy(pushBackBuffer, 0, markPushBackBuffer, 0, markPushBackLen);
412 }
413 }
414 }
415
416
417 /**
418 * Repositions this audio input stream to the position it had at the time its
419 * <code>mark</code> method was last invoked.
420 * @throws IOException if an input or output error occurs.
421 * @see #mark
422 * @see #markSupported
423 */
424 public void reset() throws IOException {
425
426 stream.reset();
427 framePos = markpos;
428 // re-create the pushback buffer
429 pushBackLen = markPushBackLen;
430 if (pushBackLen > 0) {
431 if (pushBackBuffer == null) {
432 pushBackBuffer = new byte[frameSize - 1];
433 }
434 System.arraycopy(markPushBackBuffer, 0, pushBackBuffer, 0, pushBackLen);
435 }
436 }
437
438
439 /**
440 * Tests whether this audio input stream supports the <code>mark</code> and
441 * <code>reset</code> methods.
442 * @return <code>true</code> if this stream supports the <code>mark</code>
443 * and <code>reset</code> methods; <code>false</code> otherwise
444 * @see #mark
445 * @see #reset
446 */
447 public boolean markSupported() {
448
449 return stream.markSupported();
450 }
451
452
453 /**
454 * Private inner class that makes a TargetDataLine look like an InputStream.
455 */
456 private class TargetDataLineInputStream extends InputStream {
457
458 /**
459 * The TargetDataLine on which this TargetDataLineInputStream is based.
460 */
461 TargetDataLine line;
462
463
464 TargetDataLineInputStream(TargetDataLine line) {
465 super();
466 this.line = line;
467 }
468
469
470 public int available() throws IOException {
471 return line.available();
472 }
473
474 //$$fb 2001-07-16: added this method to correctly close the underlying TargetDataLine.
475 // fixes bug 4479984
476 public void close() throws IOException {
477 // the line needs to be flushed and stopped to avoid a dead lock...
478 // Probably related to bugs 4417527, 4334868, 4383457
479 if (line.isActive()) {
480 line.flush();
481 line.stop();
482 }
483 line.close();
484 }
485
486 public int read() throws IOException {
487
488 byte[] b = new byte[1];
489
490 int value = read(b, 0, 1);
491
492 if (value == -1) {
493 return -1;
494 }
495
496 value = (int)b[0];
497
498 if (line.getFormat().getEncoding().equals(AudioFormat.Encoding.PCM_SIGNED)) {
499 value += 128;
500 }
501
502 return value;
503 }
504
505
506 public int read(byte[] b, int off, int len) throws IOException {
507 try {
508 return line.read(b, off, len);
509 } catch (IllegalArgumentException e) {
510 throw new IOException(e.getMessage());
511 }
512 }
513 }
514 }