1 /*
2 * Copyright 1999-2005 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any 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 * <p>
197 */
198 public int read() throws IOException {
199 if( frameSize != 1 ) {
200 throw new IOException("cannot read a single byte if frame size > 1");
201 }
202
203 byte[] data = new byte[1];
204 int temp = read(data);
205 if (temp <= 0) {
206 // we have a weird situation if read(byte[]) returns 0!
207 return -1;
208 }
209 return data[0] & 0xFF;
210 }
211
212
213 /**
214 * Reads some number of bytes from the audio input stream and stores them into
215 * the buffer array <code>b</code>. The number of bytes actually read is
216 * returned as an integer. This method blocks until input data is
217 * available, the end of the stream is detected, or an exception is thrown.
218 * <p>This method will always read an integral number of frames.
219 * If the length of the array is not an integral number
220 * of frames, a maximum of <code>b.length - (b.length % frameSize)
221 * </code> bytes will be read.
222 *
223 * @param b the buffer into which the data is read
224 * @return the total number of bytes read into the buffer, or -1 if there
225 * is no more data because the end of the stream has been reached
226 * @throws IOException if an input or output error occurs
227 * @see #read(byte[], int, int)
228 * @see #read()
229 * @see #available
230 */
231 public int read(byte[] b) throws IOException {
232 return read(b,0,b.length);
233 }
234
235
236 /**
237 * Reads up to a specified maximum number of bytes of data from the audio
238 * stream, putting them into the given byte array.
239 * <p>This method will always read an integral number of frames.
240 * If <code>len</code> does not specify an integral number
241 * of frames, a maximum of <code>len - (len % frameSize)
242 * </code> bytes will be read.
243 *
244 * @param b the buffer into which the data is read
245 * @param off the offset, from the beginning of array <code>b</code>, at which
246 * the data will be written
247 * @param len the maximum number of bytes to read
248 * @return the total number of bytes read into the buffer, or -1 if there
249 * is no more data because the end of the stream has been reached
250 * @throws IOException if an input or output error occurs
251 * @see #read(byte[])
252 * @see #read()
253 * @see #skip
254 * @see #available
255 */
256 public int read(byte[] b, int off, int len) throws IOException {
257
258 // make sure we don't read fractions of a frame.
259 if( (len%frameSize) != 0 ) {
260 len -= (len%frameSize);
261 if (len == 0) {
262 return 0;
263 }
264 }
265
266 if( frameLength != AudioSystem.NOT_SPECIFIED ) {
267 if( framePos >= frameLength ) {
268 return -1;
269 } else {
270
271 // don't try to read beyond our own set length in frames
272 if( (len/frameSize) > (frameLength-framePos) ) {
273 len = (int) (frameLength-framePos) * frameSize;
274 }
275 }
276 }
277
278 int bytesRead = 0;
279 int thisOff = off;
280
281 // if we've bytes left from last call to read(),
282 // use them first
283 if (pushBackLen > 0 && len >= pushBackLen) {
284 System.arraycopy(pushBackBuffer, 0,
285 b, off, pushBackLen);
286 thisOff += pushBackLen;
287 len -= pushBackLen;
288 bytesRead += pushBackLen;
289 pushBackLen = 0;
290 }
291
292 int thisBytesRead = stream.read(b, thisOff, len);
293 if (thisBytesRead == -1) {
294 return -1;
295 }
296 if (thisBytesRead > 0) {
297 bytesRead += thisBytesRead;
298 }
299 if (bytesRead > 0) {
300 pushBackLen = bytesRead % frameSize;
301 if (pushBackLen > 0) {
302 // copy everything we got from the beginning of the frame
303 // to our pushback buffer
304 if (pushBackBuffer == null) {
305 pushBackBuffer = new byte[frameSize];
306 }
307 System.arraycopy(b, off + bytesRead - pushBackLen,
308 pushBackBuffer, 0, pushBackLen);
309 bytesRead -= pushBackLen;
310 }
311 // make sure to update our framePos
312 framePos += bytesRead/frameSize;
313 }
314 return bytesRead;
315 }
316
317
318 /**
319 * Skips over and discards a specified number of bytes from this
320 * audio input stream.
321 * @param n the requested number of bytes to be skipped
322 * @return the actual number of bytes skipped
323 * @throws IOException if an input or output error occurs
324 * @see #read
325 * @see #available
326 */
327 public long skip(long n) throws IOException {
328
329 // make sure not to skip fractional frames
330 if( (n%frameSize) != 0 ) {
331 n -= (n%frameSize);
332 }
333
334 if( frameLength != AudioSystem.NOT_SPECIFIED ) {
335 // don't skip more than our set length in frames.
336 if( (n/frameSize) > (frameLength-framePos) ) {
337 n = (frameLength-framePos) * frameSize;
338 }
339 }
340 long temp = stream.skip(n);
341
342 // if no error, update our position.
343 if( temp%frameSize != 0 ) {
344
345 // Throw an IOException if we've skipped a fractional number of frames
346 throw new IOException("Could not skip an integer number of frames.");
347 }
348 if( temp >= 0 ) {
349 framePos += temp/frameSize;
350 }
351 return temp;
352
353 }
354
355
356 /**
357 * Returns the maximum number of bytes that can be read (or skipped over) from this
358 * audio input stream without blocking. This limit applies only to the next invocation of
359 * a <code>read</code> or <code>skip</code> method for this audio input stream; the limit
360 * can vary each time these methods are invoked.
361 * Depending on the underlying stream,an IOException may be thrown if this
362 * stream is closed.
363 * @return the number of bytes that can be read from this audio input stream without blocking
364 * @throws IOException if an input or output error occurs
365 * @see #read(byte[], int, int)
366 * @see #read(byte[])
367 * @see #read()
368 * @see #skip
369 */
370 public int available() throws IOException {
371
372 int temp = stream.available();
373
374 // don't return greater than our set length in frames
375 if( (frameLength != AudioSystem.NOT_SPECIFIED) && ( (temp/frameSize) > (frameLength-framePos)) ) {
376 return (int) (frameLength-framePos) * frameSize;
377 } else {
378 return temp;
379 }
380 }
381
382
383 /**
384 * Closes this audio input stream and releases any system resources associated
385 * with the stream.
386 * @throws IOException if an input or output error occurs
387 */
388 public void close() throws IOException {
389 stream.close();
390 }
391
392
393 /**
394 * Marks the current position in this audio input stream.
395 * @param readlimit the maximum number of bytes that can be read before
396 * the mark position becomes invalid.
397 * @see #reset
398 * @see #markSupported
399 */
400
401 public void mark(int readlimit) {
402
403 stream.mark(readlimit);
404 if (markSupported()) {
405 markpos = framePos;
406 // remember the pushback buffer
407 markPushBackLen = pushBackLen;
408 if (markPushBackLen > 0) {
409 if (markPushBackBuffer == null) {
410 markPushBackBuffer = new byte[frameSize];
411 }
412 System.arraycopy(pushBackBuffer, 0, markPushBackBuffer, 0, markPushBackLen);
413 }
414 }
415 }
416
417
418 /**
419 * Repositions this audio input stream to the position it had at the time its
420 * <code>mark</code> method was last invoked.
421 * @throws IOException if an input or output error occurs.
422 * @see #mark
423 * @see #markSupported
424 */
425 public void reset() throws IOException {
426
427 stream.reset();
428 framePos = markpos;
429 // re-create the pushback buffer
430 pushBackLen = markPushBackLen;
431 if (pushBackLen > 0) {
432 if (pushBackBuffer == null) {
433 pushBackBuffer = new byte[frameSize - 1];
434 }
435 System.arraycopy(markPushBackBuffer, 0, pushBackBuffer, 0, pushBackLen);
436 }
437 }
438
439
440 /**
441 * Tests whether this audio input stream supports the <code>mark</code> and
442 * <code>reset</code> methods.
443 * @return <code>true</code> if this stream supports the <code>mark</code>
444 * and <code>reset</code> methods; <code>false</code> otherwise
445 * @see #mark
446 * @see #reset
447 */
448 public boolean markSupported() {
449
450 return stream.markSupported();
451 }
452
453
454 /**
455 * Private inner class that makes a TargetDataLine look like an InputStream.
456 */
457 private class TargetDataLineInputStream extends InputStream {
458
459 /**
460 * The TargetDataLine on which this TargetDataLineInputStream is based.
461 */
462 TargetDataLine line;
463
464
465 TargetDataLineInputStream(TargetDataLine line) {
466 super();
467 this.line = line;
468 }
469
470
471 public int available() throws IOException {
472 return line.available();
473 }
474
475 //$$fb 2001-07-16: added this method to correctly close the underlying TargetDataLine.
476 // fixes bug 4479984
477 public void close() throws IOException {
478 // the line needs to be flushed and stopped to avoid a dead lock...
479 // Probably related to bugs 4417527, 4334868, 4383457
480 if (line.isActive()) {
481 line.flush();
482 line.stop();
483 }
484 line.close();
485 }
486
487 public int read() throws IOException {
488
489 byte[] b = new byte[1];
490
491 int value = read(b, 0, 1);
492
493 if (value == -1) {
494 return -1;
495 }
496
497 value = (int)b[0];
498
499 if (line.getFormat().getEncoding().equals(AudioFormat.Encoding.PCM_SIGNED)) {
500 value += 128;
501 }
502
503 return value;
504 }
505
506
507 public int read(byte[] b, int off, int len) throws IOException {
508 try {
509 return line.read(b, off, len);
510 } catch (IllegalArgumentException e) {
511 throw new IOException(e.getMessage());
512 }
513 }
514 }
515 }
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