1 /*
2 * Copyright (c) 1999, 2014, 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.IOException;
29 import java.util.Vector;
30
31 import javax.sound.sampled.AudioFormat;
32 import javax.sound.sampled.AudioInputStream;
33 import javax.sound.sampled.AudioSystem;
34
35
36 /**
37 * A-law encodes linear data, and decodes a-law data to linear data.
38 *
39 * @author Kara Kytle
40 */
41 public final class AlawCodec extends SunCodec {
42
43 /* Tables used for A-law decoding */
44
45 private static final byte[] ALAW_TABH = new byte[256];
46 private static final byte[] ALAW_TABL = new byte[256];
47
48 private static final AudioFormat.Encoding[] alawEncodings = { AudioFormat.Encoding.ALAW, AudioFormat.Encoding.PCM_SIGNED };
49
50 private static final short seg_end [] = {0xFF, 0x1FF, 0x3FF,
51 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF};
52
53 /**
54 * Initializes the decode tables
55 */
56 static {
57 for (int i=0;i<256;i++) {
58 int input = i ^ 0x55;
59 int mantissa = (input & 0xf ) << 4;
60 int segment = (input & 0x70) >> 4;
61 int value = mantissa+8;
62
63 if(segment>=1)
64 value+=0x100;
65 if(segment>1)
66 value <<= (segment -1);
67
68 if( (input & 0x80)==0 )
69 value = -value;
70
71 ALAW_TABL[i] = (byte)value;
72 ALAW_TABH[i] = (byte)(value>>8);
73 }
74 }
75
76
77 /**
78 * Constructs a new ALAW codec object.
79 */
80 public AlawCodec() {
81
82 super(alawEncodings, alawEncodings);
83 }
84
85 // NEW CODE
86
87 /**
88 */
89 public AudioFormat.Encoding[] getTargetEncodings(AudioFormat sourceFormat){
90
91 if( sourceFormat.getEncoding().equals( AudioFormat.Encoding.PCM_SIGNED )) {
92
93 if( sourceFormat.getSampleSizeInBits() == 16 ) {
94
95 AudioFormat.Encoding enc[] = new AudioFormat.Encoding[1];
96 enc[0] = AudioFormat.Encoding.ALAW;
97 return enc;
98
99 } else {
100 return new AudioFormat.Encoding[0];
101 }
102 } else if( sourceFormat.getEncoding().equals( AudioFormat.Encoding.ALAW ) ) {
103
104 if( sourceFormat.getSampleSizeInBits() == 8 ) {
105
106 AudioFormat.Encoding enc[] = new AudioFormat.Encoding[1];
107 enc[0] = AudioFormat.Encoding.PCM_SIGNED;
108 return enc;
109
110 } else {
111 return new AudioFormat.Encoding[0];
112 }
113
114 } else {
115 return new AudioFormat.Encoding[0];
116 }
117 }
118
119 /**
120 */
121 public AudioFormat[] getTargetFormats(AudioFormat.Encoding targetEncoding, AudioFormat sourceFormat){
122 if( (targetEncoding.equals( AudioFormat.Encoding.PCM_SIGNED ) && sourceFormat.getEncoding().equals( AudioFormat.Encoding.ALAW)) ||
123 (targetEncoding.equals( AudioFormat.Encoding.ALAW) && sourceFormat.getEncoding().equals( AudioFormat.Encoding.PCM_SIGNED)) ) {
124 return getOutputFormats( sourceFormat );
125 } else {
126 return new AudioFormat[0];
127 }
128 }
129
130 /**
131 */
132 public AudioInputStream getAudioInputStream(AudioFormat.Encoding targetEncoding, AudioInputStream sourceStream){
133 AudioFormat sourceFormat = sourceStream.getFormat();
134 AudioFormat.Encoding sourceEncoding = sourceFormat.getEncoding();
135
136 if( sourceEncoding.equals( targetEncoding ) ) {
137 return sourceStream;
138 } else {
139 AudioFormat targetFormat = null;
140 if( !isConversionSupported(targetEncoding,sourceStream.getFormat()) ) {
141 throw new IllegalArgumentException("Unsupported conversion: " + sourceStream.getFormat().toString() + " to " + targetEncoding.toString());
142 }
143 if( sourceEncoding.equals( AudioFormat.Encoding.ALAW ) &&
144 targetEncoding.equals( AudioFormat.Encoding.PCM_SIGNED ) ) {
145
146 targetFormat = new AudioFormat( targetEncoding,
147 sourceFormat.getSampleRate(),
148 16,
149 sourceFormat.getChannels(),
150 2*sourceFormat.getChannels(),
151 sourceFormat.getSampleRate(),
152 sourceFormat.isBigEndian());
153
154 } else if( sourceEncoding.equals( AudioFormat.Encoding.PCM_SIGNED ) &&
155 targetEncoding.equals( AudioFormat.Encoding.ALAW ) ) {
156
157 targetFormat = new AudioFormat( targetEncoding,
158 sourceFormat.getSampleRate(),
159 8,
160 sourceFormat.getChannels(),
161 sourceFormat.getChannels(),
162 sourceFormat.getSampleRate(),
163 false);
164 } else {
165 throw new IllegalArgumentException("Unsupported conversion: " + sourceStream.getFormat().toString() + " to " + targetEncoding.toString());
166 }
167 return getAudioInputStream( targetFormat, sourceStream );
168 }
169 }
170
171 /**
172 * use old code...
173 */
174 public AudioInputStream getAudioInputStream(AudioFormat targetFormat, AudioInputStream sourceStream){
175 return getConvertedStream( targetFormat, sourceStream );
176 }
177
178
179 // OLD CODE
180
181
182 /**
183 * Opens the codec with the specified parameters.
184 * @param stream stream from which data to be processed should be read
185 * @param outputFormat desired data format of the stream after processing
186 * @return stream from which processed data may be read
187 * @throws IllegalArgumentException if the format combination supplied is
188 * not supported.
189 */
190 /* public AudioInputStream getConvertedStream(AudioFormat outputFormat, AudioInputStream stream) { */
191 private AudioInputStream getConvertedStream(AudioFormat outputFormat, AudioInputStream stream) {
192
193 AudioInputStream cs = null;
194 AudioFormat inputFormat = stream.getFormat();
195
196 if( inputFormat.matches(outputFormat) ) {
197 cs = stream;
198 } else {
199 cs = (AudioInputStream) (new AlawCodecStream(stream, outputFormat));
200 }
201
202 return cs;
203 }
204
205 /**
206 * Obtains the set of output formats supported by the codec
207 * given a particular input format.
208 * If no output formats are supported for this input format,
209 * returns an array of length 0.
210 * @return array of supported output formats.
211 */
212 /* public AudioFormat[] getOutputFormats(AudioFormat inputFormat) { */
213 private AudioFormat[] getOutputFormats(AudioFormat inputFormat) {
214
215
216 Vector formats = new Vector();
217 AudioFormat format;
218
219 if ( AudioFormat.Encoding.PCM_SIGNED.equals(inputFormat.getEncoding())) {
220 format = new AudioFormat(AudioFormat.Encoding.ALAW,
221 inputFormat.getSampleRate(),
222 8,
223 inputFormat.getChannels(),
224 inputFormat.getChannels(),
225 inputFormat.getSampleRate(),
226 false );
227 formats.addElement(format);
228 }
229
230 if (AudioFormat.Encoding.ALAW.equals(inputFormat.getEncoding())) {
231 format = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
232 inputFormat.getSampleRate(),
233 16,
234 inputFormat.getChannels(),
235 inputFormat.getChannels()*2,
236 inputFormat.getSampleRate(),
237 false );
238 formats.addElement(format);
239 format = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
240 inputFormat.getSampleRate(),
241 16,
242 inputFormat.getChannels(),
243 inputFormat.getChannels()*2,
244 inputFormat.getSampleRate(),
245 true );
246 formats.addElement(format);
247 }
248
249 AudioFormat[] formatArray = new AudioFormat[formats.size()];
250 for (int i = 0; i < formatArray.length; i++) {
251 formatArray[i] = (AudioFormat)(formats.elementAt(i));
252 }
253 return formatArray;
254 }
255
256
257 final class AlawCodecStream extends AudioInputStream {
258
259 // tempBuffer required only for encoding (when encode is true)
260 private static final int tempBufferSize = 64;
261 private byte tempBuffer [] = null;
262
263 /**
264 * True to encode to a-law, false to decode to linear
265 */
266 boolean encode = false;
267
268 AudioFormat encodeFormat;
269 AudioFormat decodeFormat;
270
271 byte tabByte1[] = null;
272 byte tabByte2[] = null;
273 int highByte = 0;
274 int lowByte = 1;
275
276 AlawCodecStream(AudioInputStream stream, AudioFormat outputFormat) {
277
278 super(stream, outputFormat, -1);
279
280 AudioFormat inputFormat = stream.getFormat();
281
282 // throw an IllegalArgumentException if not ok
283 if ( ! (isConversionSupported(outputFormat, inputFormat)) ) {
284
285 throw new IllegalArgumentException("Unsupported conversion: " + inputFormat.toString() + " to " + outputFormat.toString());
286 }
287
288 //$$fb 2002-07-18: fix for 4714846: JavaSound ULAW (8-bit) encoder erroneously depends on endian-ness
289 boolean PCMIsBigEndian;
290
291 // determine whether we are encoding or decoding
292 if (AudioFormat.Encoding.ALAW.equals(inputFormat.getEncoding())) {
293 encode = false;
294 encodeFormat = inputFormat;
295 decodeFormat = outputFormat;
296 PCMIsBigEndian = outputFormat.isBigEndian();
297 } else {
298 encode = true;
299 encodeFormat = outputFormat;
300 decodeFormat = inputFormat;
301 PCMIsBigEndian = inputFormat.isBigEndian();
302 tempBuffer = new byte[tempBufferSize];
303 }
304
305 if (PCMIsBigEndian) {
306 tabByte1 = ALAW_TABH;
307 tabByte2 = ALAW_TABL;
308 highByte = 0;
309 lowByte = 1;
310 } else {
311 tabByte1 = ALAW_TABL;
312 tabByte2 = ALAW_TABH;
313 highByte = 1;
314 lowByte = 0;
315 }
316
317 // set the AudioInputStream length in frames if we know it
318 if (stream instanceof AudioInputStream) {
319 frameLength = stream.getFrameLength();
320 }
321
322 // set framePos to zero
323 framePos = 0;
324 frameSize = inputFormat.getFrameSize();
325 if( frameSize==AudioSystem.NOT_SPECIFIED ) {
326 frameSize=1;
327 }
328 }
329
330
331 /*
332 * $$jb 2/23/99
333 * Used to determine segment number in aLaw encoding
334 */
335 private short search(short val, short table[], short size) {
336 for(short i = 0; i < size; i++) {
337 if (val <= table[i]) { return i; }
338 }
339 return size;
340 }
341
342 /**
343 * Note that this won't actually read anything; must read in
344 * two-byte units.
345 */
346 public int read() throws IOException {
347
348 byte[] b = new byte[1];
349 return read(b, 0, b.length);
350 }
351
352
353 public int read(byte[] b) throws IOException {
354
355 return read(b, 0, b.length);
356 }
357
358 public int read(byte[] b, int off, int len) throws IOException {
359
360 // don't read fractional frames
361 if( len%frameSize != 0 ) {
362 len -= (len%frameSize);
363 }
364
365 if (encode) {
366
367 short QUANT_MASK = 0xF;
368 short SEG_SHIFT = 4;
369 short mask;
370 short seg;
371 int adj;
372 int i;
373
374 short sample;
375 byte enc;
376
377 int readCount = 0;
378 int currentPos = off;
379 int readLeft = len*2;
380 int readLen = ( (readLeft>tempBufferSize) ? tempBufferSize : readLeft );
381
382 while ((readCount = super.read(tempBuffer,0,readLen))>0) {
383
384 for (i = 0; i < readCount; i+=2) {
385
386 /* Get the sample from the tempBuffer */
387 sample = (short)(( (tempBuffer[i + highByte]) << 8) & 0xFF00);
388 sample |= (short)( (tempBuffer[i + lowByte]) & 0xFF);
389
390 if(sample >= 0) {
391 mask = 0xD5;
392 } else {
393 mask = 0x55;
394 sample = (short)(-sample - 8);
395 }
396 /* Convert the scaled magnitude to segment number. */
397 seg = search(sample, seg_end, (short) 8);
398 /*
399 * Combine the sign, segment, quantization bits
400 */
401 if (seg >= 8) { /* out of range, return maximum value. */
402 enc = (byte) (0x7F ^ mask);
403 } else {
404 enc = (byte) (seg << SEG_SHIFT);
405 if(seg < 2) {
406 enc |= (byte) ( (sample >> 4) & QUANT_MASK);
407 } else {
408 enc |= (byte) ( (sample >> (seg + 3)) & QUANT_MASK );
409 }
410 enc ^= mask;
411 }
412 /* Now put the encoded sample where it belongs */
413 b[currentPos] = enc;
414 currentPos++;
415 }
416 /* And update pointers and counters for next iteration */
417 readLeft -= readCount;
418 readLen = ( (readLeft>tempBufferSize) ? tempBufferSize : readLeft );
419 }
420
421 if( currentPos==off && readCount<0 ) { // EOF or error
422 return readCount;
423 }
424
425 return (currentPos - off); /* Number of bytes written to new buffer */
426
427 } else {
428
429 int i;
430 int readLen = len/2;
431 int readOffset = off + len/2;
432 int readCount = super.read(b, readOffset, readLen);
433
434 for (i = off; i < (off + (readCount*2)); i+=2) {
435 b[i] = tabByte1[b[readOffset] & 0xFF];
436 b[i+1] = tabByte2[b[readOffset] & 0xFF];
437 readOffset++;
438 }
439
440 if( readCount<0 ) { // EOF or error
441 return readCount;
442 }
443
444 return (i - off);
445 }
446 }
447 } // end class AlawCodecStream
448 } // end class ALAW