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[Faustine.git] / interpretor / libsndfile-1.0.25 / src / G72x / g72x.c
1 /*
2 * This source code is a product of Sun Microsystems, Inc. and is provided
3 * for unrestricted use. Users may copy or modify this source code without
4 * charge.
5 *
6 * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
7 * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
8 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
9 *
10 * Sun source code is provided with no support and without any obligation on
11 * the part of Sun Microsystems, Inc. to assist in its use, correction,
12 * modification or enhancement.
13 *
14 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
15 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE
16 * OR ANY PART THEREOF.
17 *
18 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
19 * or profits or other special, indirect and consequential damages, even if
20 * Sun has been advised of the possibility of such damages.
21 *
22 * Sun Microsystems, Inc.
23 * 2550 Garcia Avenue
24 * Mountain View, California 94043
25 */
26
27 /*
28 * g72x.c
29 *
30 * Common routines for G.721 and G.723 conversions.
31 */
32
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36
37 #include "g72x.h"
38 #include "g72x_priv.h"
39
40 static G72x_STATE * g72x_state_new (void) ;
41 static int unpack_bytes (int bits, int blocksize, const unsigned char * block, short * samples) ;
42 static int pack_bytes (int bits, const short * samples, unsigned char * block) ;
43
44 static
45 short power2 [15] =
46 { 1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80,
47 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000
48 } ;
49
50 /*
51 * quan()
52 *
53 * quantizes the input val against the table of size short integers.
54 * It returns i if table[i - 1] <= val < table[i].
55 *
56 * Using linear search for simple coding.
57 */
58 static
59 int quan (int val, short *table, int size)
60 {
61 int i;
62
63 for (i = 0; i < size; i++)
64 if (val < *table++)
65 break;
66 return (i);
67 }
68
69 /*
70 * fmult()
71 *
72 * returns the integer product of the 14-bit integer "an" and
73 * "floating point" representation (4-bit exponent, 6-bit mantessa) "srn".
74 */
75 static
76 int fmult (int an, int srn)
77 {
78 short anmag, anexp, anmant;
79 short wanexp, wanmant;
80 short retval;
81
82 anmag = (an > 0) ? an : ((-an) & 0x1FFF);
83 anexp = quan(anmag, power2, 15) - 6;
84 anmant = (anmag == 0) ? 32 :
85 (anexp >= 0) ? anmag >> anexp : anmag << -anexp;
86 wanexp = anexp + ((srn >> 6) & 0xF) - 13;
87
88 /*
89 ** The original was :
90 ** wanmant = (anmant * (srn & 0x3F) + 0x30) >> 4 ;
91 ** but could see no valid reason for the + 0x30.
92 ** Removed it and it improved the SNR of the codec.
93 */
94
95 wanmant = (anmant * (srn & 0x3F)) >> 4 ;
96
97 retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) :
98 (wanmant >> -wanexp);
99
100 return (((an ^ srn) < 0) ? -retval : retval);
101 }
102
103 static G72x_STATE * g72x_state_new (void)
104 { return calloc (1, sizeof (G72x_STATE)) ;
105 }
106
107 /*
108 * private_init_state()
109 *
110 * This routine initializes and/or resets the G72x_PRIVATE structure
111 * pointed to by 'state_ptr'.
112 * All the initial state values are specified in the CCITT G.721 document.
113 */
114 void private_init_state (G72x_STATE *state_ptr)
115 {
116 int cnta;
117
118 state_ptr->yl = 34816;
119 state_ptr->yu = 544;
120 state_ptr->dms = 0;
121 state_ptr->dml = 0;
122 state_ptr->ap = 0;
123 for (cnta = 0; cnta < 2; cnta++) {
124 state_ptr->a[cnta] = 0;
125 state_ptr->pk[cnta] = 0;
126 state_ptr->sr[cnta] = 32;
127 }
128 for (cnta = 0; cnta < 6; cnta++) {
129 state_ptr->b[cnta] = 0;
130 state_ptr->dq[cnta] = 32;
131 }
132 state_ptr->td = 0;
133 } /* private_init_state */
134
135 struct g72x_state * g72x_reader_init (int codec, int *blocksize, int *samplesperblock)
136 { G72x_STATE *pstate ;
137
138 if ((pstate = g72x_state_new ()) == NULL)
139 return NULL ;
140
141 private_init_state (pstate) ;
142
143 pstate->encoder = NULL ;
144
145 switch (codec)
146 { case G723_16_BITS_PER_SAMPLE : /* 2 bits per sample. */
147 pstate->decoder = g723_16_decoder ;
148 *blocksize = G723_16_BYTES_PER_BLOCK ;
149 *samplesperblock = G723_16_SAMPLES_PER_BLOCK ;
150 pstate->codec_bits = 2 ;
151 pstate->blocksize = G723_16_BYTES_PER_BLOCK ;
152 pstate->samplesperblock = G723_16_SAMPLES_PER_BLOCK ;
153 break ;
154
155 case G723_24_BITS_PER_SAMPLE : /* 3 bits per sample. */
156 pstate->decoder = g723_24_decoder ;
157 *blocksize = G723_24_BYTES_PER_BLOCK ;
158 *samplesperblock = G723_24_SAMPLES_PER_BLOCK ;
159 pstate->codec_bits = 3 ;
160 pstate->blocksize = G723_24_BYTES_PER_BLOCK ;
161 pstate->samplesperblock = G723_24_SAMPLES_PER_BLOCK ;
162 break ;
163
164 case G721_32_BITS_PER_SAMPLE : /* 4 bits per sample. */
165 pstate->decoder = g721_decoder ;
166 *blocksize = G721_32_BYTES_PER_BLOCK ;
167 *samplesperblock = G721_32_SAMPLES_PER_BLOCK ;
168 pstate->codec_bits = 4 ;
169 pstate->blocksize = G721_32_BYTES_PER_BLOCK ;
170 pstate->samplesperblock = G721_32_SAMPLES_PER_BLOCK ;
171 break ;
172
173 case G721_40_BITS_PER_SAMPLE : /* 5 bits per sample. */
174 pstate->decoder = g723_40_decoder ;
175 *blocksize = G721_40_BYTES_PER_BLOCK ;
176 *samplesperblock = G721_40_SAMPLES_PER_BLOCK ;
177 pstate->codec_bits = 5 ;
178 pstate->blocksize = G721_40_BYTES_PER_BLOCK ;
179 pstate->samplesperblock = G721_40_SAMPLES_PER_BLOCK ;
180 break ;
181
182 default :
183 free (pstate) ;
184 return NULL ;
185 } ;
186
187 return pstate ;
188 } /* g72x_reader_init */
189
190 struct g72x_state * g72x_writer_init (int codec, int *blocksize, int *samplesperblock)
191 { G72x_STATE *pstate ;
192
193 if ((pstate = g72x_state_new ()) == NULL)
194 return NULL ;
195
196 private_init_state (pstate) ;
197 pstate->decoder = NULL ;
198
199 switch (codec)
200 { case G723_16_BITS_PER_SAMPLE : /* 2 bits per sample. */
201 pstate->encoder = g723_16_encoder ;
202 *blocksize = G723_16_BYTES_PER_BLOCK ;
203 *samplesperblock = G723_16_SAMPLES_PER_BLOCK ;
204 pstate->codec_bits = 2 ;
205 pstate->blocksize = G723_16_BYTES_PER_BLOCK ;
206 pstate->samplesperblock = G723_16_SAMPLES_PER_BLOCK ;
207 break ;
208
209 case G723_24_BITS_PER_SAMPLE : /* 3 bits per sample. */
210 pstate->encoder = g723_24_encoder ;
211 *blocksize = G723_24_BYTES_PER_BLOCK ;
212 *samplesperblock = G723_24_SAMPLES_PER_BLOCK ;
213 pstate->codec_bits = 3 ;
214 pstate->blocksize = G723_24_BYTES_PER_BLOCK ;
215 pstate->samplesperblock = G723_24_SAMPLES_PER_BLOCK ;
216 break ;
217
218 case G721_32_BITS_PER_SAMPLE : /* 4 bits per sample. */
219 pstate->encoder = g721_encoder ;
220 *blocksize = G721_32_BYTES_PER_BLOCK ;
221 *samplesperblock = G721_32_SAMPLES_PER_BLOCK ;
222 pstate->codec_bits = 4 ;
223 pstate->blocksize = G721_32_BYTES_PER_BLOCK ;
224 pstate->samplesperblock = G721_32_SAMPLES_PER_BLOCK ;
225 break ;
226
227 case G721_40_BITS_PER_SAMPLE : /* 5 bits per sample. */
228 pstate->encoder = g723_40_encoder ;
229 *blocksize = G721_40_BYTES_PER_BLOCK ;
230 *samplesperblock = G721_40_SAMPLES_PER_BLOCK ;
231 pstate->codec_bits = 5 ;
232 pstate->blocksize = G721_40_BYTES_PER_BLOCK ;
233 pstate->samplesperblock = G721_40_SAMPLES_PER_BLOCK ;
234 break ;
235
236 default :
237 free (pstate) ;
238 return NULL ;
239 } ;
240
241 return pstate ;
242 } /* g72x_writer_init */
243
244 int g72x_decode_block (G72x_STATE *pstate, const unsigned char *block, short *samples)
245 { int k, count ;
246
247 count = unpack_bytes (pstate->codec_bits, pstate->blocksize, block, samples) ;
248
249 for (k = 0 ; k < count ; k++)
250 samples [k] = pstate->decoder (samples [k], pstate) ;
251
252 return 0 ;
253 } /* g72x_decode_block */
254
255 int g72x_encode_block (G72x_STATE *pstate, short *samples, unsigned char *block)
256 { int k, count ;
257
258 for (k = 0 ; k < pstate->samplesperblock ; k++)
259 samples [k] = pstate->encoder (samples [k], pstate) ;
260
261 count = pack_bytes (pstate->codec_bits, samples, block) ;
262
263 return count ;
264 } /* g72x_encode_block */
265
266 /*
267 * predictor_zero()
268 *
269 * computes the estimated signal from 6-zero predictor.
270 *
271 */
272 int predictor_zero (G72x_STATE *state_ptr)
273 {
274 int i;
275 int sezi;
276
277 sezi = fmult(state_ptr->b[0] >> 2, state_ptr->dq[0]);
278 for (i = 1; i < 6; i++) /* ACCUM */
279 sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]);
280 return (sezi);
281 }
282 /*
283 * predictor_pole()
284 *
285 * computes the estimated signal from 2-pole predictor.
286 *
287 */
288 int predictor_pole(G72x_STATE *state_ptr)
289 {
290 return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) +
291 fmult(state_ptr->a[0] >> 2, state_ptr->sr[0]));
292 }
293 /*
294 * step_size()
295 *
296 * computes the quantization step size of the adaptive quantizer.
297 *
298 */
299 int step_size (G72x_STATE *state_ptr)
300 {
301 int y;
302 int dif;
303 int al;
304
305 if (state_ptr->ap >= 256)
306 return (state_ptr->yu);
307 else {
308 y = state_ptr->yl >> 6;
309 dif = state_ptr->yu - y;
310 al = state_ptr->ap >> 2;
311 if (dif > 0)
312 y += (dif * al) >> 6;
313 else if (dif < 0)
314 y += (dif * al + 0x3F) >> 6;
315 return (y);
316 }
317 }
318
319 /*
320 * quantize()
321 *
322 * Given a raw sample, 'd', of the difference signal and a
323 * quantization step size scale factor, 'y', this routine returns the
324 * ADPCM codeword to which that sample gets quantized. The step
325 * size scale factor division operation is done in the log base 2 domain
326 * as a subtraction.
327 */
328 int quantize(
329 int d, /* Raw difference signal sample */
330 int y, /* Step size multiplier */
331 short *table, /* quantization table */
332 int size) /* table size of short integers */
333 {
334 short dqm; /* Magnitude of 'd' */
335 short expon; /* Integer part of base 2 log of 'd' */
336 short mant; /* Fractional part of base 2 log */
337 short dl; /* Log of magnitude of 'd' */
338 short dln; /* Step size scale factor normalized log */
339 int i;
340
341 /*
342 * LOG
343 *
344 * Compute base 2 log of 'd', and store in 'dl'.
345 */
346 dqm = abs(d);
347 expon = quan(dqm >> 1, power2, 15);
348 mant = ((dqm << 7) >> expon) & 0x7F; /* Fractional portion. */
349 dl = (expon << 7) + mant;
350
351 /*
352 * SUBTB
353 *
354 * "Divide" by step size multiplier.
355 */
356 dln = dl - (y >> 2);
357
358 /*
359 * QUAN
360 *
361 * Obtain codword i for 'd'.
362 */
363 i = quan(dln, table, size);
364 if (d < 0) /* take 1's complement of i */
365 return ((size << 1) + 1 - i);
366 else if (i == 0) /* take 1's complement of 0 */
367 return ((size << 1) + 1); /* new in 1988 */
368 else
369 return (i);
370 }
371 /*
372 * reconstruct()
373 *
374 * Returns reconstructed difference signal 'dq' obtained from
375 * codeword 'i' and quantization step size scale factor 'y'.
376 * Multiplication is performed in log base 2 domain as addition.
377 */
378 int
379 reconstruct(
380 int sign, /* 0 for non-negative value */
381 int dqln, /* G.72x codeword */
382 int y) /* Step size multiplier */
383 {
384 short dql; /* Log of 'dq' magnitude */
385 short dex; /* Integer part of log */
386 short dqt;
387 short dq; /* Reconstructed difference signal sample */
388
389 dql = dqln + (y >> 2); /* ADDA */
390
391 if (dql < 0) {
392 return ((sign) ? -0x8000 : 0);
393 } else { /* ANTILOG */
394 dex = (dql >> 7) & 15;
395 dqt = 128 + (dql & 127);
396 dq = (dqt << 7) >> (14 - dex);
397 return ((sign) ? (dq - 0x8000) : dq);
398 }
399 }
400
401
402 /*
403 * update()
404 *
405 * updates the state variables for each output code
406 */
407 void
408 update(
409 int code_size, /* distinguish 723_40 with others */
410 int y, /* quantizer step size */
411 int wi, /* scale factor multiplier */
412 int fi, /* for long/short term energies */
413 int dq, /* quantized prediction difference */
414 int sr, /* reconstructed signal */
415 int dqsez, /* difference from 2-pole predictor */
416 G72x_STATE *state_ptr) /* coder state pointer */
417 {
418 int cnt;
419 short mag, expon; /* Adaptive predictor, FLOAT A */
420 short a2p = 0; /* LIMC */
421 short a1ul; /* UPA1 */
422 short pks1; /* UPA2 */
423 short fa1;
424 char tr; /* tone/transition detector */
425 short ylint, thr2, dqthr;
426 short ylfrac, thr1;
427 short pk0;
428
429 pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */
430
431 mag = dq & 0x7FFF; /* prediction difference magnitude */
432 /* TRANS */
433 ylint = state_ptr->yl >> 15; /* exponent part of yl */
434 ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */
435 thr1 = (32 + ylfrac) << ylint; /* threshold */
436 thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */
437 dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */
438 if (state_ptr->td == 0) /* signal supposed voice */
439 tr = 0;
440 else if (mag <= dqthr) /* supposed data, but small mag */
441 tr = 0; /* treated as voice */
442 else /* signal is data (modem) */
443 tr = 1;
444
445 /*
446 * Quantizer scale factor adaptation.
447 */
448
449 /* FUNCTW & FILTD & DELAY */
450 /* update non-steady state step size multiplier */
451 state_ptr->yu = y + ((wi - y) >> 5);
452
453 /* LIMB */
454 if (state_ptr->yu < 544) /* 544 <= yu <= 5120 */
455 state_ptr->yu = 544;
456 else if (state_ptr->yu > 5120)
457 state_ptr->yu = 5120;
458
459 /* FILTE & DELAY */
460 /* update steady state step size multiplier */
461 state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6);
462
463 /*
464 * Adaptive predictor coefficients.
465 */
466 if (tr == 1) { /* reset a's and b's for modem signal */
467 state_ptr->a[0] = 0;
468 state_ptr->a[1] = 0;
469 state_ptr->b[0] = 0;
470 state_ptr->b[1] = 0;
471 state_ptr->b[2] = 0;
472 state_ptr->b[3] = 0;
473 state_ptr->b[4] = 0;
474 state_ptr->b[5] = 0;
475 } else { /* update a's and b's */
476 pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */
477
478 /* update predictor pole a[1] */
479 a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7);
480 if (dqsez != 0) {
481 fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0];
482 if (fa1 < -8191) /* a2p = function of fa1 */
483 a2p -= 0x100;
484 else if (fa1 > 8191)
485 a2p += 0xFF;
486 else
487 a2p += fa1 >> 5;
488
489 if (pk0 ^ state_ptr->pk[1])
490 { /* LIMC */
491 if (a2p <= -12160)
492 a2p = -12288;
493 else if (a2p >= 12416)
494 a2p = 12288;
495 else
496 a2p -= 0x80;
497 }
498 else if (a2p <= -12416)
499 a2p = -12288;
500 else if (a2p >= 12160)
501 a2p = 12288;
502 else
503 a2p += 0x80;
504 }
505
506 /* TRIGB & DELAY */
507 state_ptr->a[1] = a2p;
508
509 /* UPA1 */
510 /* update predictor pole a[0] */
511 state_ptr->a[0] -= state_ptr->a[0] >> 8;
512 if (dqsez != 0)
513 { if (pks1 == 0)
514 state_ptr->a[0] += 192;
515 else
516 state_ptr->a[0] -= 192;
517 } ;
518
519 /* LIMD */
520 a1ul = 15360 - a2p;
521 if (state_ptr->a[0] < -a1ul)
522 state_ptr->a[0] = -a1ul;
523 else if (state_ptr->a[0] > a1ul)
524 state_ptr->a[0] = a1ul;
525
526 /* UPB : update predictor zeros b[6] */
527 for (cnt = 0; cnt < 6; cnt++) {
528 if (code_size == 5) /* for 40Kbps G.723 */
529 state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9;
530 else /* for G.721 and 24Kbps G.723 */
531 state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8;
532 if (dq & 0x7FFF) { /* XOR */
533 if ((dq ^ state_ptr->dq[cnt]) >= 0)
534 state_ptr->b[cnt] += 128;
535 else
536 state_ptr->b[cnt] -= 128;
537 }
538 }
539 }
540
541 for (cnt = 5; cnt > 0; cnt--)
542 state_ptr->dq[cnt] = state_ptr->dq[cnt-1];
543 /* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */
544 if (mag == 0) {
545 state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0xFC20;
546 } else {
547 expon = quan(mag, power2, 15);
548 state_ptr->dq[0] = (dq >= 0) ?
549 (expon << 6) + ((mag << 6) >> expon) :
550 (expon << 6) + ((mag << 6) >> expon) - 0x400;
551 }
552
553 state_ptr->sr[1] = state_ptr->sr[0];
554 /* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */
555 if (sr == 0) {
556 state_ptr->sr[0] = 0x20;
557 } else if (sr > 0) {
558 expon = quan(sr, power2, 15);
559 state_ptr->sr[0] = (expon << 6) + ((sr << 6) >> expon);
560 } else if (sr > -32768) {
561 mag = -sr;
562 expon = quan(mag, power2, 15);
563 state_ptr->sr[0] = (expon << 6) + ((mag << 6) >> expon) - 0x400;
564 } else
565 state_ptr->sr[0] = (short) 0xFC20;
566
567 /* DELAY A */
568 state_ptr->pk[1] = state_ptr->pk[0];
569 state_ptr->pk[0] = pk0;
570
571 /* TONE */
572 if (tr == 1) /* this sample has been treated as data */
573 state_ptr->td = 0; /* next one will be treated as voice */
574 else if (a2p < -11776) /* small sample-to-sample correlation */
575 state_ptr->td = 1; /* signal may be data */
576 else /* signal is voice */
577 state_ptr->td = 0;
578
579 /*
580 * Adaptation speed control.
581 */
582 state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */
583 state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */
584
585 if (tr == 1)
586 state_ptr->ap = 256;
587 else if (y < 1536) /* SUBTC */
588 state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
589 else if (state_ptr->td == 1)
590 state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
591 else if (abs((state_ptr->dms << 2) - state_ptr->dml) >=
592 (state_ptr->dml >> 3))
593 state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
594 else
595 state_ptr->ap += (-state_ptr->ap) >> 4;
596
597 return ;
598 } /* update */
599
600 /*------------------------------------------------------------------------------
601 */
602
603 static int
604 unpack_bytes (int bits, int blocksize, const unsigned char * block, short * samples)
605 { unsigned int in_buffer = 0 ;
606 unsigned char in_byte ;
607 int k, in_bits = 0, bindex = 0 ;
608
609 for (k = 0 ; bindex <= blocksize && k < G72x_BLOCK_SIZE ; k++)
610 { if (in_bits < bits)
611 { in_byte = block [bindex++] ;
612
613 in_buffer |= (in_byte << in_bits);
614 in_bits += 8;
615 }
616 samples [k] = in_buffer & ((1 << bits) - 1);
617 in_buffer >>= bits;
618 in_bits -= bits;
619 } ;
620
621 return k ;
622 } /* unpack_bytes */
623
624 static int
625 pack_bytes (int bits, const short * samples, unsigned char * block)
626 {
627 unsigned int out_buffer = 0 ;
628 int k, bindex = 0, out_bits = 0 ;
629 unsigned char out_byte ;
630
631 for (k = 0 ; k < G72x_BLOCK_SIZE ; k++)
632 { out_buffer |= (samples [k] << out_bits) ;
633 out_bits += bits ;
634 if (out_bits >= 8)
635 { out_byte = out_buffer & 0xFF ;
636 out_bits -= 8 ;
637 out_buffer >>= 8 ;
638 block [bindex++] = out_byte ;
639 }
640 } ;
641
642 return bindex ;
643 } /* pack_bytes */
644
An OCaml-based interpreter for Faust and its vector extension