1 /* 2 * Copyright (c) 1999, 2005, 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 * <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 }