1 /*
2 * Copyright (c) 1999, 2011, 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 com.sun.media.sound;
27
28 import java.io.InputStream;
29 import java.io.IOException;
30
31 import java.util.Vector;
32
33 import javax.sound.sampled.AudioFormat;
34 import javax.sound.sampled.AudioSystem;
35 import javax.sound.sampled.AudioInputStream;
36
37
38 /**
39 * A-law encodes linear data, and decodes a-law data to linear data.
40 *
41 * @author Kara Kytle
42 */
43 public class AlawCodec extends SunCodec {
44
45 /* Tables used for A-law decoding */
46
47 final static byte ALAW_TABH[] = new byte[256];
48 final static byte ALAW_TABL[] = new byte[256];
49
50 private static final AudioFormat.Encoding[] alawEncodings = { AudioFormat.Encoding.ALAW, AudioFormat.Encoding.PCM_SIGNED };
51
52 private static final short seg_end [] = {0xFF, 0x1FF, 0x3FF,
53 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF};
54
55 /**
56 * Initializes the decode tables
57 */
58 static {
59 for (int i=0;i<256;i++) {
60 int input = i ^ 0x55;
61 int mantissa = (input & 0xf ) << 4;
62 int segment = (input & 0x70) >> 4;
63 int value = mantissa+8;
64
65 if(segment>=1)
66 value+=0x100;
67 if(segment>1)
68 value <<= (segment -1);
69
70 if( (input & 0x80)==0 )
71 value = -value;
72
73 ALAW_TABL[i] = (byte)value;
74 ALAW_TABH[i] = (byte)(value>>8);
75 }
76 }
77
78
79 /**
80 * Constructs a new ALAW codec object.
81 */
82 public AlawCodec() {
83
84 super(alawEncodings, alawEncodings);
85 }
86
87 // NEW CODE
88
89 /**
90 */
91 public AudioFormat.Encoding[] getTargetEncodings(AudioFormat sourceFormat){
92
93 if( sourceFormat.getEncoding().equals( AudioFormat.Encoding.PCM_SIGNED )) {
94
95 if( sourceFormat.getSampleSizeInBits() == 16 ) {
96
97 AudioFormat.Encoding enc[] = new AudioFormat.Encoding[1];
98 enc[0] = AudioFormat.Encoding.ALAW;
99 return enc;
100
101 } else {
102 return new AudioFormat.Encoding[0];
103 }
104 } else if( sourceFormat.getEncoding().equals( AudioFormat.Encoding.ALAW ) ) {
105
106 if( sourceFormat.getSampleSizeInBits() == 8 ) {
107
108 AudioFormat.Encoding enc[] = new AudioFormat.Encoding[1];
109 enc[0] = AudioFormat.Encoding.PCM_SIGNED;
110 return enc;
111
112 } else {
113 return new AudioFormat.Encoding[0];
114 }
115
116 } else {
117 return new AudioFormat.Encoding[0];
118 }
119 }
120
121 /**
122 */
123 public AudioFormat[] getTargetFormats(AudioFormat.Encoding targetEncoding, AudioFormat sourceFormat){
124 if( (targetEncoding.equals( AudioFormat.Encoding.PCM_SIGNED ) && sourceFormat.getEncoding().equals( AudioFormat.Encoding.ALAW)) ||
125 (targetEncoding.equals( AudioFormat.Encoding.ALAW) && sourceFormat.getEncoding().equals( AudioFormat.Encoding.PCM_SIGNED)) ) {
126 return getOutputFormats( sourceFormat );
127 } else {
128 return new AudioFormat[0];
129 }
130 }
131
132 /**
133 */
134 public AudioInputStream getAudioInputStream(AudioFormat.Encoding targetEncoding, AudioInputStream sourceStream){
135 AudioFormat sourceFormat = sourceStream.getFormat();
136 AudioFormat.Encoding sourceEncoding = sourceFormat.getEncoding();
137
138 if( sourceEncoding.equals( targetEncoding ) ) {
139 return sourceStream;
140 } else {
141 AudioFormat targetFormat = null;
142 if( !isConversionSupported(targetEncoding,sourceStream.getFormat()) ) {
143 throw new IllegalArgumentException("Unsupported conversion: " + sourceStream.getFormat().toString() + " to " + targetEncoding.toString());
144 }
145 if( sourceEncoding.equals( AudioFormat.Encoding.ALAW ) &&
146 targetEncoding.equals( AudioFormat.Encoding.PCM_SIGNED ) ) {
147
148 targetFormat = new AudioFormat( targetEncoding,
149 sourceFormat.getSampleRate(),
150 16,
151 sourceFormat.getChannels(),
152 2*sourceFormat.getChannels(),
153 sourceFormat.getSampleRate(),
154 sourceFormat.isBigEndian());
155
156 } else if( sourceEncoding.equals( AudioFormat.Encoding.PCM_SIGNED ) &&
157 targetEncoding.equals( AudioFormat.Encoding.ALAW ) ) {
158
159 targetFormat = new AudioFormat( targetEncoding,
160 sourceFormat.getSampleRate(),
161 8,
162 sourceFormat.getChannels(),
163 sourceFormat.getChannels(),
164 sourceFormat.getSampleRate(),
165 false);
166 } else {
167 throw new IllegalArgumentException("Unsupported conversion: " + sourceStream.getFormat().toString() + " to " + targetEncoding.toString());
168 }
169 return getAudioInputStream( targetFormat, sourceStream );
170 }
171 }
172
173 /**
174 * use old code...
175 */
176 public AudioInputStream getAudioInputStream(AudioFormat targetFormat, AudioInputStream sourceStream){
177 return getConvertedStream( targetFormat, sourceStream );
178 }
179
180
181 // OLD CODE
182
183
184 /**
185 * Opens the codec with the specified parameters.
186 * @param stream stream from which data to be processed should be read
187 * @param outputFormat desired data format of the stream after processing
188 * @return stream from which processed data may be read
189 * @throws IllegalArgumentException if the format combination supplied is
190 * not supported.
191 */
192 /* public AudioInputStream getConvertedStream(AudioFormat outputFormat, AudioInputStream stream) { */
193 private AudioInputStream getConvertedStream(AudioFormat outputFormat, AudioInputStream stream) {
194
195 AudioInputStream cs = null;
196 AudioFormat inputFormat = stream.getFormat();
197
198 if( inputFormat.matches(outputFormat) ) {
199 cs = stream;
200 } else {
201 cs = (AudioInputStream) (new AlawCodecStream(stream, outputFormat));
202 }
203
204 return cs;
205 }
206
207 /**
208 * Obtains the set of output formats supported by the codec
209 * given a particular input format.
210 * If no output formats are supported for this input format,
211 * returns an array of length 0.
212 * @return array of supported output formats.
213 */
214 /* public AudioFormat[] getOutputFormats(AudioFormat inputFormat) { */
215 private AudioFormat[] getOutputFormats(AudioFormat inputFormat) {
216
217
218 Vector formats = new Vector();
219 AudioFormat format;
220
221 if ( AudioFormat.Encoding.PCM_SIGNED.equals(inputFormat.getEncoding())) {
222 format = new AudioFormat(AudioFormat.Encoding.ALAW,
223 inputFormat.getSampleRate(),
224 8,
225 inputFormat.getChannels(),
226 inputFormat.getChannels(),
227 inputFormat.getSampleRate(),
228 false );
229 formats.addElement(format);
230 }
231
232 if (AudioFormat.Encoding.ALAW.equals(inputFormat.getEncoding())) {
233 format = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
234 inputFormat.getSampleRate(),
235 16,
236 inputFormat.getChannels(),
237 inputFormat.getChannels()*2,
238 inputFormat.getSampleRate(),
239 false );
240 formats.addElement(format);
241 format = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
242 inputFormat.getSampleRate(),
243 16,
244 inputFormat.getChannels(),
245 inputFormat.getChannels()*2,
246 inputFormat.getSampleRate(),
247 true );
248 formats.addElement(format);
249 }
250
251 AudioFormat[] formatArray = new AudioFormat[formats.size()];
252 for (int i = 0; i < formatArray.length; i++) {
253 formatArray[i] = (AudioFormat)(formats.elementAt(i));
254 }
255 return formatArray;
256 }
257
258
259 class AlawCodecStream extends AudioInputStream {
260
261 // tempBuffer required only for encoding (when encode is true)
262 private static final int tempBufferSize = 64;
263 private byte tempBuffer [] = null;
264
265 /**
266 * True to encode to a-law, false to decode to linear
267 */
268 boolean encode = false;
269
270 AudioFormat encodeFormat;
271 AudioFormat decodeFormat;
272
273 byte tabByte1[] = null;
274 byte tabByte2[] = null;
275 int highByte = 0;
276 int lowByte = 1;
277
278 AlawCodecStream(AudioInputStream stream, AudioFormat outputFormat) {
279
280 super(stream, outputFormat, -1);
281
282 AudioFormat inputFormat = stream.getFormat();
283
284 // throw an IllegalArgumentException if not ok
285 if ( ! (isConversionSupported(outputFormat, inputFormat)) ) {
286
287 throw new IllegalArgumentException("Unsupported conversion: " + inputFormat.toString() + " to " + outputFormat.toString());
288 }
289
290 //$$fb 2002-07-18: fix for 4714846: JavaSound ULAW (8-bit) encoder erroneously depends on endian-ness
291 boolean PCMIsBigEndian;
292
293 // determine whether we are encoding or decoding
294 if (AudioFormat.Encoding.ALAW.equals(inputFormat.getEncoding())) {
295 encode = false;
296 encodeFormat = inputFormat;
297 decodeFormat = outputFormat;
298 PCMIsBigEndian = outputFormat.isBigEndian();
299 } else {
300 encode = true;
301 encodeFormat = outputFormat;
302 decodeFormat = inputFormat;
303 PCMIsBigEndian = inputFormat.isBigEndian();
304 tempBuffer = new byte[tempBufferSize];
305 }
306
307 if (PCMIsBigEndian) {
308 tabByte1 = ALAW_TABH;
309 tabByte2 = ALAW_TABL;
310 highByte = 0;
311 lowByte = 1;
312 } else {
313 tabByte1 = ALAW_TABL;
314 tabByte2 = ALAW_TABH;
315 highByte = 1;
316 lowByte = 0;
317 }
318
319 // set the AudioInputStream length in frames if we know it
320 if (stream instanceof AudioInputStream) {
321 frameLength = ((AudioInputStream)stream).getFrameLength();
322 }
323
324 // set framePos to zero
325 framePos = 0;
326 frameSize = inputFormat.getFrameSize();
327 if( frameSize==AudioSystem.NOT_SPECIFIED ) {
328 frameSize=1;
329 }
330 }
331
332
333 /*
334 * $$jb 2/23/99
335 * Used to determine segment number in aLaw encoding
336 */
337 private short search(short val, short table[], short size) {
338 for(short i = 0; i < size; i++) {
339 if (val <= table[i]) { return i; }
340 }
341 return size;
342 }
343
344 /**
345 * Note that this won't actually read anything; must read in
346 * two-byte units.
347 */
348 public int read() throws IOException {
349
350 byte[] b = new byte[1];
351 return (int)read(b, 0, b.length);
352 }
353
354
355 public int read(byte[] b) throws IOException {
356
357 return read(b, 0, b.length);
358 }
359
360 public int read(byte[] b, int off, int len) throws IOException {
361
362 // don't read fractional frames
363 if( len%frameSize != 0 ) {
364 len -= (len%frameSize);
365 }
366
367 if (encode) {
368
369 short QUANT_MASK = 0xF;
370 short SEG_SHIFT = 4;
371 short mask;
372 short seg;
373 int adj;
374 int i;
375
376 short sample;
377 byte enc;
378
379 int readCount = 0;
380 int currentPos = off;
381 int readLeft = len*2;
382 int readLen = ( (readLeft>tempBufferSize) ? tempBufferSize : readLeft );
383
384 while ((readCount = super.read(tempBuffer,0,readLen))>0) {
385
386 for (i = 0; i < readCount; i+=2) {
387
388 /* Get the sample from the tempBuffer */
389 sample = (short)(( (tempBuffer[i + highByte]) << 8) & 0xFF00);
390 sample |= (short)( (tempBuffer[i + lowByte]) & 0xFF);
391
392 if(sample >= 0) {
393 mask = 0xD5;
394 } else {
395 mask = 0x55;
396 sample = (short)(-sample - 8);
397 }
398 /* Convert the scaled magnitude to segment number. */
399 seg = search(sample, seg_end, (short) 8);
400 /*
401 * Combine the sign, segment, quantization bits
402 */
403 if (seg >= 8) { /* out of range, return maximum value. */
404 enc = (byte) (0x7F ^ mask);
405 } else {
406 enc = (byte) (seg << SEG_SHIFT);
407 if(seg < 2) {
408 enc |= (byte) ( (sample >> 4) & QUANT_MASK);
409 } else {
410 enc |= (byte) ( (sample >> (seg + 3)) & QUANT_MASK );
411 }
412 enc ^= mask;
413 }
414 /* Now put the encoded sample where it belongs */
415 b[currentPos] = enc;
416 currentPos++;
417 }
418 /* And update pointers and counters for next iteration */
419 readLeft -= readCount;
420 readLen = ( (readLeft>tempBufferSize) ? tempBufferSize : readLeft );
421 }
422
423 if( currentPos==off && readCount<0 ) { // EOF or error
424 return readCount;
425 }
426
427 return (currentPos - off); /* Number of bytes written to new buffer */
428
429 } else {
430
431 int i;
432 int readLen = len/2;
433 int readOffset = off + len/2;
434 int readCount = super.read(b, readOffset, readLen);
435
436 for (i = off; i < (off + (readCount*2)); i+=2) {
437 b[i] = (byte)tabByte1[b[readOffset] & 0xFF];
438 b[i+1] = (byte)tabByte2[b[readOffset] & 0xFF];
439 readOffset++;
440 }
441
442 if( readCount<0 ) { // EOF or error
443 return readCount;
444 }
445
446 return (i - off);
447 }
448 }
449 } // end class AlawCodecStream
450 } // end class ALAW