Asterisk - The Open Source Telephony Project GIT-master-f3e88d3
codec_g726.c
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1/*
2 * Asterisk -- An open source telephony toolkit.
3 *
4 * Copyright (C) 1999 - 2006, Digium, Inc.
5 *
6 * Mark Spencer <markster@digium.com>
7 * Kevin P. Fleming <kpfleming@digium.com>
8 *
9 * Based on frompcm.c and topcm.c from the Emiliano MIPL browser/
10 * interpreter. See http://www.bsdtelephony.com.mx
11 *
12 * See http://www.asterisk.org for more information about
13 * the Asterisk project. Please do not directly contact
14 * any of the maintainers of this project for assistance;
15 * the project provides a web site, mailing lists and IRC
16 * channels for your use.
17 *
18 * This program is free software, distributed under the terms of
19 * the GNU General Public License Version 2. See the LICENSE file
20 * at the top of the source tree.
21 */
22
23/*! \file
24 *
25 * \brief codec_g726.c - translate between signed linear and ITU G.726-32kbps (both RFC3551 and AAL2 codeword packing)
26 *
27 * \ingroup codecs
28 */
29
30/*** MODULEINFO
31 <support_level>core</support_level>
32 ***/
33
34#include "asterisk.h"
35
36#include "asterisk/lock.h"
38#include "asterisk/module.h"
39#include "asterisk/config.h"
40#include "asterisk/translate.h"
41#include "asterisk/utils.h"
42
43#define WANT_ASM
44#include "log2comp.h"
45
46/* define NOT_BLI to use a faster but not bit-level identical version */
47/* #define NOT_BLI */
48
49#if defined(NOT_BLI)
50# if defined(_MSC_VER)
51typedef __int64 sint64;
52# elif defined(__GNUC__)
53typedef long long sint64;
54# else
55# error 64-bit integer type is not defined for your compiler/platform
56# endif
57#endif
58
59#define BUFFER_SAMPLES 8096 /* size for the translation buffers */
60#define BUF_SHIFT 5
61
62/* Sample frame data */
63#include "asterisk/slin.h"
64#include "ex_g726.h"
65
66/*
67 * The following is the definition of the state structure
68 * used by the G.726 encoder and decoder to preserve their internal
69 * state between successive calls. The meanings of the majority
70 * of the state structure fields are explained in detail in the
71 * CCITT Recommendation G.721. The field names are essentially identical
72 * to variable names in the bit level description of the coding algorithm
73 * included in this Recommendation.
74 */
75struct g726_state {
76 long yl; /* Locked or steady state step size multiplier. */
77 int yu; /* Unlocked or non-steady state step size multiplier. */
78 int dms; /* Short term energy estimate. */
79 int dml; /* Long term energy estimate. */
80 int ap; /* Linear weighting coefficient of 'yl' and 'yu'. */
81 int a[2]; /* Coefficients of pole portion of prediction filter.
82 * stored as fixed-point 1==2^14 */
83 int b[6]; /* Coefficients of zero portion of prediction filter.
84 * stored as fixed-point 1==2^14 */
85 int pk[2]; /* Signs of previous two samples of a partially
86 * reconstructed signal. */
87 int dq[6]; /* Previous 6 samples of the quantized difference signal
88 * stored as fixed point 1==2^12,
89 * or in internal floating point format */
90 int sr[2]; /* Previous 2 samples of the quantized difference signal
91 * stored as fixed point 1==2^12,
92 * or in internal floating point format */
93 int td; /* delayed tone detect, new in 1988 version */
94};
95
96static int qtab_721[7] = {-124, 80, 178, 246, 300, 349, 400};
97/*
98 * Maps G.721 code word to reconstructed scale factor normalized log
99 * magnitude values.
100 */
101static int _dqlntab[16] = {-2048, 4, 135, 213, 273, 323, 373, 425,
102 425, 373, 323, 273, 213, 135, 4, -2048};
103
104/* Maps G.721 code word to log of scale factor multiplier. */
105static int _witab[16] = {-12, 18, 41, 64, 112, 198, 355, 1122,
106 1122, 355, 198, 112, 64, 41, 18, -12};
107/*
108 * Maps G.721 code words to a set of values whose long and short
109 * term averages are computed and then compared to give an indication
110 * how stationary (steady state) the signal is.
111 */
112static int _fitab[16] = {0, 0, 0, 0x200, 0x200, 0x200, 0x600, 0xE00,
113 0xE00, 0x600, 0x200, 0x200, 0x200, 0, 0, 0};
114
115
116/*
117 * g72x_init_state()
118 *
119 * This routine initializes and/or resets the g726_state structure
120 * pointed to by 'state_ptr'.
121 * All the initial state values are specified in the CCITT G.721 document.
122 */
123static void g726_init_state(struct g726_state *state_ptr)
124{
125 int cnta;
126
127 state_ptr->yl = 34816;
128 state_ptr->yu = 544;
129 state_ptr->dms = 0;
130 state_ptr->dml = 0;
131 state_ptr->ap = 0;
132 for (cnta = 0; cnta < 2; cnta++) {
133 state_ptr->a[cnta] = 0;
134 state_ptr->pk[cnta] = 0;
135#ifdef NOT_BLI
136 state_ptr->sr[cnta] = 1;
137#else
138 state_ptr->sr[cnta] = 32;
139#endif
140 }
141 for (cnta = 0; cnta < 6; cnta++) {
142 state_ptr->b[cnta] = 0;
143#ifdef NOT_BLI
144 state_ptr->dq[cnta] = 1;
145#else
146 state_ptr->dq[cnta] = 32;
147#endif
148 }
149 state_ptr->td = 0;
150}
151
152/*
153 * quan()
154 *
155 * quantizes the input val against the table of integers.
156 * It returns i if table[i - 1] <= val < table[i].
157 *
158 * Using linear search for simple coding.
159 */
160static int quan(int val, int *table, int size)
161{
162 int i;
163
164 for (i = 0; i < size && val >= *table; ++i, ++table)
165 ;
166 return i;
167}
168
169#ifdef NOT_BLI /* faster non-identical version */
170
171/*
172 * predictor_zero()
173 *
174 * computes the estimated signal from 6-zero predictor.
175 *
176 */
177static int predictor_zero(struct g726_state *state_ptr)
178{ /* divide by 2 is necessary here to handle negative numbers correctly */
179 int i;
180 sint64 sezi;
181 for (sezi = 0, i = 0; i < 6; i++) /* ACCUM */
182 sezi += (sint64)state_ptr->b[i] * state_ptr->dq[i];
183 return (int)(sezi >> 13) / 2 /* 2^14 */;
184}
185
186/*
187 * predictor_pole()
188 *
189 * computes the estimated signal from 2-pole predictor.
190 *
191 */
192static int predictor_pole(struct g726_state *state_ptr)
193{ /* divide by 2 is necessary here to handle negative numbers correctly */
194 return (int)(((sint64)state_ptr->a[1] * state_ptr->sr[1] +
195 (sint64)state_ptr->a[0] * state_ptr->sr[0]) >> 13) / 2 /* 2^14 */;
196}
197
198#else /* NOT_BLI - identical version */
199/*
200 * fmult()
201 *
202 * returns the integer product of the fixed-point number "an" (1==2^12) and
203 * "floating point" representation (4-bit exponent, 6-bit mantessa) "srn".
204 */
205static int fmult(int an, int srn)
206{
207 int anmag, anexp, anmant;
208 int wanexp, wanmant;
209 int retval;
210
211 anmag = (an > 0) ? an : ((-an) & 0x1FFF);
212 anexp = ilog2(anmag) - 5;
213 anmant = (anmag == 0) ? 32 :
214 (anexp >= 0) ? anmag >> anexp : anmag << -anexp;
215 wanexp = anexp + ((srn >> 6) & 0xF) - 13;
216
217 wanmant = (anmant * (srn & 077) + 0x30) >> 4;
218 retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) :
219 (wanmant >> -wanexp);
220
221 return (((an ^ srn) < 0) ? -retval : retval);
222}
223
224static int predictor_zero(struct g726_state *state_ptr)
225{
226 int i;
227 int sezi;
228 for (sezi = 0, i = 0; i < 6; i++) /* ACCUM */
229 sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]);
230 return sezi;
231}
232
233static int predictor_pole(struct g726_state *state_ptr)
234{
235 return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) +
236 fmult(state_ptr->a[0] >> 2, state_ptr->sr[0]));
237}
238
239#endif /* NOT_BLI */
240
241/*
242 * step_size()
243 *
244 * computes the quantization step size of the adaptive quantizer.
245 *
246 */
247static int step_size(struct g726_state *state_ptr)
248{
249 int y, dif, al;
250
251 if (state_ptr->ap >= 256) {
252 return state_ptr->yu;
253 }
254
255 y = state_ptr->yl >> 6;
256 dif = state_ptr->yu - y;
257 al = state_ptr->ap >> 2;
258
259 if (dif > 0) {
260 y += (dif * al) >> 6;
261 } else if (dif < 0) {
262 y += (dif * al + 0x3F) >> 6;
263 }
264 return y;
265}
266
267/*
268 * quantize()
269 *
270 * Given a raw sample, 'd', of the difference signal and a
271 * quantization step size scale factor, 'y', this routine returns the
272 * ADPCM codeword to which that sample gets quantized. The step
273 * size scale factor division operation is done in the log base 2 domain
274 * as a subtraction.
275 */
276static int quantize(
277 int d, /* Raw difference signal sample */
278 int y, /* Step size multiplier */
279 int *table, /* quantization table */
280 int size) /* table size of integers */
281{
282 int dqm; /* Magnitude of 'd' */
283 int exp; /* Integer part of base 2 log of 'd' */
284 int mant; /* Fractional part of base 2 log */
285 int dl; /* Log of magnitude of 'd' */
286 int dln; /* Step size scale factor normalized log */
287 int i;
288
289 /*
290 * LOG
291 *
292 * Compute base 2 log of 'd', and store in 'dl'.
293 */
294 dqm = abs(d);
295 exp = ilog2(dqm);
296 if (exp < 0) {
297 exp = 0;
298 }
299 mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */
300 dl = (exp << 7) | mant;
301
302 /*
303 * SUBTB
304 *
305 * "Divide" by step size multiplier.
306 */
307 dln = dl - (y >> 2);
308
309 /*
310 * QUAN
311 *
312 * Obtain codeword i for 'd'.
313 */
314 i = quan(dln, table, size);
315 if (d < 0) { /* take 1's complement of i */
316 return ((size << 1) + 1 - i);
317 } else if (i == 0) { /* take 1's complement of 0 */
318 return ((size << 1) + 1); /* new in 1988 */
319 } else {
320 return i;
321 }
322}
323
324/*
325 * reconstruct()
326 *
327 * Returns reconstructed difference signal 'dq' obtained from
328 * codeword 'i' and quantization step size scale factor 'y'.
329 * Multiplication is performed in log base 2 domain as addition.
330 */
331static int reconstruct(
332 int sign, /* 0 for non-negative value */
333 int dqln, /* G.72x codeword */
334 int y) /* Step size multiplier */
335{
336 int dql; /* Log of 'dq' magnitude */
337 int dex; /* Integer part of log */
338 int dqt;
339 int dq; /* Reconstructed difference signal sample */
340
341 dql = dqln + (y >> 2); /* ADDA */
342
343 if (dql < 0) {
344#ifdef NOT_BLI
345 return (sign) ? -1 : 1;
346#else
347 return (sign) ? -0x8000 : 0;
348#endif
349 } else { /* ANTILOG */
350 dex = (dql >> 7) & 15;
351 dqt = 128 + (dql & 127);
352#ifdef NOT_BLI
353 dq = ((dqt << 19) >> (14 - dex));
354 return (sign) ? -dq : dq;
355#else
356 dq = (dqt << 7) >> (14 - dex);
357 return (sign) ? (dq - 0x8000) : dq;
358#endif
359 }
360}
361
362/*
363 * update()
364 *
365 * updates the state variables for each output code
366 */
367static void update(
368 int code_size, /* distinguish 723_40 with others */
369 int y, /* quantizer step size */
370 int wi, /* scale factor multiplier */
371 int fi, /* for long/short term energies */
372 int dq, /* quantized prediction difference */
373 int sr, /* reconstructed signal */
374 int dqsez, /* difference from 2-pole predictor */
375 struct g726_state *state_ptr) /* coder state pointer */
376{
377 int cnt;
378 int mag; /* Adaptive predictor, FLOAT A */
379#ifndef NOT_BLI
380 int exp;
381#endif
382 int a2p=0; /* LIMC */
383 int a1ul; /* UPA1 */
384 int pks1; /* UPA2 */
385 int fa1;
386 int tr; /* tone/transition detector */
387 int ylint, thr2, dqthr;
388 int ylfrac, thr1;
389 int pk0;
390
391 pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */
392
393#ifdef NOT_BLI
394 mag = abs(dq / 0x1000); /* prediction difference magnitude */
395#else
396 mag = dq & 0x7FFF; /* prediction difference magnitude */
397#endif
398 /* TRANS */
399 ylint = state_ptr->yl >> 15; /* exponent part of yl */
400 ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */
401 thr1 = (32 + ylfrac) << ylint; /* threshold */
402 thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */
403 dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */
404 if (state_ptr->td == 0) { /* signal supposed voice */
405 tr = 0;
406 } else if (mag <= dqthr) { /* supposed data, but small mag */
407 tr = 0; /* treated as voice */
408 } else { /* signal is data (modem) */
409 tr = 1;
410 }
411 /*
412 * Quantizer scale factor adaptation.
413 */
414
415 /* FUNCTW & FILTD & DELAY */
416 /* update non-steady state step size multiplier */
417 state_ptr->yu = y + ((wi - y) >> 5);
418
419 /* LIMB */
420 if (state_ptr->yu < 544) { /* 544 <= yu <= 5120 */
421 state_ptr->yu = 544;
422 } else if (state_ptr->yu > 5120) {
423 state_ptr->yu = 5120;
424 }
425
426 /* FILTE & DELAY */
427 /* update steady state step size multiplier */
428 state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6);
429
430 /*
431 * Adaptive predictor coefficients.
432 */
433 if (tr == 1) { /* reset a's and b's for modem signal */
434 state_ptr->a[0] = 0;
435 state_ptr->a[1] = 0;
436 state_ptr->b[0] = 0;
437 state_ptr->b[1] = 0;
438 state_ptr->b[2] = 0;
439 state_ptr->b[3] = 0;
440 state_ptr->b[4] = 0;
441 state_ptr->b[5] = 0;
442 } else { /* update a's and b's */
443 pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */
444
445 /* update predictor pole a[1] */
446 a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7);
447 if (dqsez != 0) {
448 fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0];
449 if (fa1 < -8191) { /* a2p = function of fa1 */
450 a2p -= 0x100;
451 } else if (fa1 > 8191) {
452 a2p += 0xFF;
453 } else {
454 a2p += fa1 >> 5;
455 }
456
457 if (pk0 ^ state_ptr->pk[1]) {
458 /* LIMC */
459 if (a2p <= -12160) {
460 a2p = -12288;
461 } else if (a2p >= 12416) {
462 a2p = 12288;
463 } else {
464 a2p -= 0x80;
465 }
466 } else if (a2p <= -12416) {
467 a2p = -12288;
468 } else if (a2p >= 12160) {
469 a2p = 12288;
470 } else {
471 a2p += 0x80;
472 }
473 }
474
475 /* TRIGB & DELAY */
476 state_ptr->a[1] = a2p;
477
478 /* UPA1 */
479 /* update predictor pole a[0] */
480 state_ptr->a[0] -= state_ptr->a[0] >> 8;
481 if (dqsez != 0) {
482 if (pks1 == 0)
483 state_ptr->a[0] += 192;
484 else
485 state_ptr->a[0] -= 192;
486 }
487 /* LIMD */
488 a1ul = 15360 - a2p;
489 if (state_ptr->a[0] < -a1ul) {
490 state_ptr->a[0] = -a1ul;
491 } else if (state_ptr->a[0] > a1ul) {
492 state_ptr->a[0] = a1ul;
493 }
494
495 /* UPB : update predictor zeros b[6] */
496 for (cnt = 0; cnt < 6; cnt++) {
497 if (code_size == 5) { /* for 40Kbps G.723 */
498 state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9;
499 } else { /* for G.721 and 24Kbps G.723 */
500 state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8;
501 }
502 if (mag) { /* XOR */
503 if ((dq ^ state_ptr->dq[cnt]) >= 0) {
504 state_ptr->b[cnt] += 128;
505 } else {
506 state_ptr->b[cnt] -= 128;
507 }
508 }
509 }
510 }
511
512 for (cnt = 5; cnt > 0; cnt--)
513 state_ptr->dq[cnt] = state_ptr->dq[cnt-1];
514#ifdef NOT_BLI
515 state_ptr->dq[0] = dq;
516#else
517 /* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */
518 if (mag == 0) {
519 state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0x20 - 0x400;
520 } else {
521 exp = ilog2(mag) + 1;
522 state_ptr->dq[0] = (dq >= 0) ?
523 (exp << 6) + ((mag << 6) >> exp) :
524 (exp << 6) + ((mag << 6) >> exp) - 0x400;
525 }
526#endif
527
528 state_ptr->sr[1] = state_ptr->sr[0];
529#ifdef NOT_BLI
530 state_ptr->sr[0] = sr;
531#else
532 /* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */
533 if (sr == 0) {
534 state_ptr->sr[0] = 0x20;
535 } else if (sr > 0) {
536 exp = ilog2(sr) + 1;
537 state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp);
538 } else if (sr > -0x8000) {
539 mag = -sr;
540 exp = ilog2(mag) + 1;
541 state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400;
542 } else
543 state_ptr->sr[0] = 0x20 - 0x400;
544#endif
545
546 /* DELAY A */
547 state_ptr->pk[1] = state_ptr->pk[0];
548 state_ptr->pk[0] = pk0;
549
550 /* TONE */
551 if (tr == 1) { /* this sample has been treated as data */
552 state_ptr->td = 0; /* next one will be treated as voice */
553 } else if (a2p < -11776) { /* small sample-to-sample correlation */
554 state_ptr->td = 1; /* signal may be data */
555 } else { /* signal is voice */
556 state_ptr->td = 0;
557 }
558
559 /*
560 * Adaptation speed control.
561 */
562 state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */
563 state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */
564
565 if (tr == 1) {
566 state_ptr->ap = 256;
567 } else if (y < 1536) { /* SUBTC */
568 state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
569 } else if (state_ptr->td == 1) {
570 state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
571 } else if (abs((state_ptr->dms << 2) - state_ptr->dml) >=
572 (state_ptr->dml >> 3)) {
573 state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
574 } else {
575 state_ptr->ap += (-state_ptr->ap) >> 4;
576 }
577}
578
579/*
580 * g726_decode()
581 *
582 * Description:
583 *
584 * Decodes a 4-bit code of G.726-32 encoded data of i and
585 * returns the resulting linear PCM, A-law or u-law value.
586 * return -1 for unknown out_coding value.
587 */
588static int g726_decode(int i, struct g726_state *state_ptr)
589{
590 int sezi, sez, se; /* ACCUM */
591 int y; /* MIX */
592 int sr; /* ADDB */
593 int dq;
594 int dqsez;
595
596 i &= 0x0f; /* mask to get proper bits */
597#ifdef NOT_BLI
598 sezi = predictor_zero(state_ptr);
599 sez = sezi;
600 se = sezi + predictor_pole(state_ptr); /* estimated signal */
601#else
602 sezi = predictor_zero(state_ptr);
603 sez = sezi >> 1;
604 se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */
605#endif
606
607 y = step_size(state_ptr); /* dynamic quantizer step size */
608
609 dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized diff. */
610
611#ifdef NOT_BLI
612 sr = se + dq; /* reconst. signal */
613 dqsez = dq + sez; /* pole prediction diff. */
614#else
615 sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */
616 dqsez = sr - se + sez; /* pole prediction diff. */
617#endif
618
619 update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr);
620
621#ifdef NOT_BLI
622 return (sr >> 10); /* sr was 26-bit dynamic range */
623#else
624 return (sr << 2); /* sr was 14-bit dynamic range */
625#endif
626}
627
628/*
629 * g726_encode()
630 *
631 * Encodes the input vale of linear PCM, A-law or u-law data sl and returns
632 * the resulting code. -1 is returned for unknown input coding value.
633 */
634static int g726_encode(int sl, struct g726_state *state_ptr)
635{
636 int sezi, se, sez; /* ACCUM */
637 int d; /* SUBTA */
638 int sr; /* ADDB */
639 int y; /* MIX */
640 int dqsez; /* ADDC */
641 int dq, i;
642
643#ifdef NOT_BLI
644 sl <<= 10; /* 26-bit dynamic range */
645
646 sezi = predictor_zero(state_ptr);
647 sez = sezi;
648 se = sezi + predictor_pole(state_ptr); /* estimated signal */
649#else
650 sl >>= 2; /* 14-bit dynamic range */
651
652 sezi = predictor_zero(state_ptr);
653 sez = sezi >> 1;
654 se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */
655#endif
656
657 d = sl - se; /* estimation difference */
658
659 /* quantize the prediction difference */
660 y = step_size(state_ptr); /* quantizer step size */
661#ifdef NOT_BLI
662 d /= 0x1000;
663#endif
664 i = quantize(d, y, qtab_721, 7); /* i = G726 code */
665
666 dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized est diff */
667
668#ifdef NOT_BLI
669 sr = se + dq; /* reconst. signal */
670 dqsez = dq + sez; /* pole prediction diff. */
671#else
672 sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */
673 dqsez = sr - se + sez; /* pole prediction diff. */
674#endif
675
676 update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr);
677
678 return i;
679}
680
681/*
682 * Private workspace for translating signed linear signals to G726.
683 * Don't bother to define two distinct structs.
684 */
685
687 /* buffer any odd byte in input - 0x80 + (value & 0xf) if present */
688 unsigned char next_flag;
690};
691
692/*! \brief init a new instance of g726_coder_pvt. */
693static int lintog726_new(struct ast_trans_pvt *pvt)
694{
695 struct g726_coder_pvt *tmp = pvt->pvt;
696
697 g726_init_state(&tmp->g726);
698
699 return 0;
700}
701
702/*! \brief decode packed 4-bit G726 values (AAL2 packing) and store in buffer. */
703static int g726aal2tolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
704{
705 struct g726_coder_pvt *tmp = pvt->pvt;
706 unsigned char *src = f->data.ptr;
707 int16_t *dst = pvt->outbuf.i16 + pvt->samples;
708 unsigned int i;
709
710 for (i = 0; i < f->datalen; i++) {
711 *dst++ = g726_decode((src[i] >> 4) & 0xf, &tmp->g726);
712 *dst++ = g726_decode(src[i] & 0x0f, &tmp->g726);
713 }
714
715 pvt->samples += f->samples;
716 pvt->datalen += 2 * f->samples; /* 2 bytes/sample */
717
718 return 0;
719}
720
721/*! \brief compress and store data (4-bit G726 samples, AAL2 packing) in outbuf */
722static int lintog726aal2_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
723{
724 struct g726_coder_pvt *tmp = pvt->pvt;
725 int16_t *src = f->data.ptr;
726 unsigned int i;
727
728 for (i = 0; i < f->samples; i++) {
729 unsigned char d = g726_encode(src[i], &tmp->g726); /* this sample */
730
731 if (tmp->next_flag & 0x80) { /* merge with leftover sample */
732 pvt->outbuf.c[pvt->datalen++] = ((tmp->next_flag & 0xf)<< 4) | d;
733 pvt->samples += 2; /* 2 samples per byte */
734 tmp->next_flag = 0;
735 } else {
736 tmp->next_flag = 0x80 | d;
737 }
738 }
739
740 return 0;
741}
742
743/*! \brief decode packed 4-bit G726 values (RFC3551 packing) and store in buffer. */
744static int g726tolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
745{
746 struct g726_coder_pvt *tmp = pvt->pvt;
747 unsigned char *src = f->data.ptr;
748 int16_t *dst = pvt->outbuf.i16 + pvt->samples;
749 unsigned int i;
750
751 for (i = 0; i < f->datalen; i++) {
752 *dst++ = g726_decode(src[i] & 0x0f, &tmp->g726);
753 *dst++ = g726_decode((src[i] >> 4) & 0xf, &tmp->g726);
754 }
755
756 pvt->samples += f->samples;
757 pvt->datalen += 2 * f->samples; /* 2 bytes/sample */
758
759 return 0;
760}
761
762/*! \brief compress and store data (4-bit G726 samples, RFC3551 packing) in outbuf */
763static int lintog726_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
764{
765 struct g726_coder_pvt *tmp = pvt->pvt;
766 int16_t *src = f->data.ptr;
767 unsigned int i;
768
769 for (i = 0; i < f->samples; i++) {
770 unsigned char d = g726_encode(src[i], &tmp->g726); /* this sample */
771
772 if (tmp->next_flag & 0x80) { /* merge with leftover sample */
773 pvt->outbuf.c[pvt->datalen++] = (d << 4) | (tmp->next_flag & 0xf);
774 pvt->samples += 2; /* 2 samples per byte */
775 tmp->next_flag = 0;
776 } else {
777 tmp->next_flag = 0x80 | d;
778 }
779 }
780
781 return 0;
782}
783
784static struct ast_translator g726tolin = {
785 .name = "g726tolin",
786 .src_codec = {
787 .name = "g726",
788 .type = AST_MEDIA_TYPE_AUDIO,
789 .sample_rate = 8000,
790 },
791 .dst_codec = {
792 .name = "slin",
793 .type = AST_MEDIA_TYPE_AUDIO,
794 .sample_rate = 8000,
795 },
796 .format = "slin",
797 .newpvt = lintog726_new, /* same for both directions */
798 .framein = g726tolin_framein,
799 .sample = g726_sample,
800 .desc_size = sizeof(struct g726_coder_pvt),
801 .buffer_samples = BUFFER_SAMPLES,
802 .buf_size = BUFFER_SAMPLES * 2,
803};
804
805static struct ast_translator lintog726 = {
806 .name = "lintog726",
807 .src_codec = {
808 .name = "slin",
809 .type = AST_MEDIA_TYPE_AUDIO,
810 .sample_rate = 8000,
811 },
812 .dst_codec = {
813 .name = "g726",
814 .type = AST_MEDIA_TYPE_AUDIO,
815 .sample_rate = 8000,
816 },
817 .format = "g726",
818 .newpvt = lintog726_new, /* same for both directions */
819 .framein = lintog726_framein,
820 .sample = slin8_sample,
821 .desc_size = sizeof(struct g726_coder_pvt),
822 .buffer_samples = BUFFER_SAMPLES,
823 .buf_size = BUFFER_SAMPLES/2,
824};
825
827 .name = "g726aal2tolin",
828 .src_codec = {
829 .name = "g726aal2",
830 .type = AST_MEDIA_TYPE_AUDIO,
831 .sample_rate = 8000,
832 },
833 .dst_codec = {
834 .name = "slin",
835 .type = AST_MEDIA_TYPE_AUDIO,
836 .sample_rate = 8000,
837 },
838 .format = "slin",
839 .newpvt = lintog726_new, /* same for both directions */
840 .framein = g726aal2tolin_framein,
841 .sample = g726_sample,
842 .desc_size = sizeof(struct g726_coder_pvt),
843 .buffer_samples = BUFFER_SAMPLES,
844 .buf_size = BUFFER_SAMPLES * 2,
845};
846
848 .name = "lintog726aal2",
849 .src_codec = {
850 .name = "slin",
851 .type = AST_MEDIA_TYPE_AUDIO,
852 .sample_rate = 8000,
853 },
854 .dst_codec = {
855 .name = "g726aal2",
856 .type = AST_MEDIA_TYPE_AUDIO,
857 .sample_rate = 8000,
858 },
859 .format = "g726aal2",
860 .newpvt = lintog726_new, /* same for both directions */
861 .framein = lintog726aal2_framein,
862 .sample = slin8_sample,
863 .desc_size = sizeof(struct g726_coder_pvt),
864 .buffer_samples = BUFFER_SAMPLES,
865 .buf_size = BUFFER_SAMPLES / 2,
866};
867
868static int unload_module(void)
869{
870 int res = 0;
871
874
877
878 return res;
879}
880
881static int load_module(void)
882{
883 int res = 0;
884
887
890
891 if (res) {
894 }
895
897}
898
899AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "ITU G.726-32kbps G726 Transcoder",
900 .support_level = AST_MODULE_SUPPORT_CORE,
901 .load = load_module,
902 .unload = unload_module,
if(!yyg->yy_init)
Definition: ast_expr2f.c:854
Asterisk main include file. File version handling, generic pbx functions.
static int tmp()
Definition: bt_open.c:389
static char * table
Definition: cdr_odbc.c:55
@ AST_MEDIA_TYPE_AUDIO
Definition: codec.h:32
static int step_size(struct g726_state *state_ptr)
Definition: codec_g726.c:247
static int qtab_721[7]
Definition: codec_g726.c:96
static int predictor_zero(struct g726_state *state_ptr)
Definition: codec_g726.c:224
#define BUFFER_SAMPLES
Definition: codec_g726.c:59
static int fmult(int an, int srn)
Definition: codec_g726.c:205
static int g726tolin_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
decode packed 4-bit G726 values (RFC3551 packing) and store in buffer.
Definition: codec_g726.c:744
static struct ast_translator lintog726aal2
Definition: codec_g726.c:847
static int quan(int val, int *table, int size)
Definition: codec_g726.c:160
static int _witab[16]
Definition: codec_g726.c:105
static void g726_init_state(struct g726_state *state_ptr)
Definition: codec_g726.c:123
static int lintog726aal2_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
compress and store data (4-bit G726 samples, AAL2 packing) in outbuf
Definition: codec_g726.c:722
static int _dqlntab[16]
Definition: codec_g726.c:101
static struct ast_translator g726tolin
Definition: codec_g726.c:784
static struct ast_translator lintog726
Definition: codec_g726.c:805
static void update(int code_size, int y, int wi, int fi, int dq, int sr, int dqsez, struct g726_state *state_ptr)
Definition: codec_g726.c:367
static int lintog726_new(struct ast_trans_pvt *pvt)
init a new instance of g726_coder_pvt.
Definition: codec_g726.c:693
static int quantize(int d, int y, int *table, int size)
Definition: codec_g726.c:276
static struct ast_translator g726aal2tolin
Definition: codec_g726.c:826
static int predictor_pole(struct g726_state *state_ptr)
Definition: codec_g726.c:233
static int reconstruct(int sign, int dqln, int y)
Definition: codec_g726.c:331
static int _fitab[16]
Definition: codec_g726.c:112
static int g726aal2tolin_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
decode packed 4-bit G726 values (AAL2 packing) and store in buffer.
Definition: codec_g726.c:703
static int load_module(void)
Definition: codec_g726.c:881
static int unload_module(void)
Definition: codec_g726.c:868
static int g726_decode(int i, struct g726_state *state_ptr)
Definition: codec_g726.c:588
static int g726_encode(int sl, struct g726_state *state_ptr)
Definition: codec_g726.c:634
static int lintog726_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
compress and store data (4-bit G726 samples, RFC3551 packing) in outbuf
Definition: codec_g726.c:763
short int16_t
Definition: db.h:59
4-bit G.726 data
static struct ast_frame * g726_sample(void)
Definition: ex_g726.h:18
#define abs(x)
Definition: f2c.h:195
static ENTRY retval
Definition: hsearch.c:50
Configuration File Parser.
A set of macros to manage forward-linked lists.
Asterisk locking-related definitions:
log2comp.h - various base 2 log computation versions
static int ilog2(int val)
Definition: log2comp.h:67
Asterisk module definitions.
@ AST_MODFLAG_DEFAULT
Definition: module.h:329
#define AST_MODULE_INFO(keystr, flags_to_set, desc, fields...)
Definition: module.h:557
@ AST_MODULE_SUPPORT_CORE
Definition: module.h:121
#define ASTERISK_GPL_KEY
The text the key() function should return.
Definition: module.h:46
@ AST_MODULE_LOAD_SUCCESS
Definition: module.h:70
@ AST_MODULE_LOAD_DECLINE
Module has failed to load, may be in an inconsistent state.
Definition: module.h:78
static struct ast_frame * slin8_sample(void)
Definition: slin.h:64
Data structure associated with a single frame of data.
union ast_frame::@226 data
Default structure for translators, with the basic fields and buffers, all allocated as part of the sa...
Definition: translate.h:213
void * pvt
Definition: translate.h:219
int datalen
actual space used in outbuf
Definition: translate.h:218
union ast_trans_pvt::@287 outbuf
int16_t * i16
Definition: translate.h:223
Descriptor of a translator.
Definition: translate.h:137
char name[80]
Definition: translate.h:138
unsigned char next_flag
Definition: codec_g726.c:688
struct g726_state g726
Definition: codec_g726.c:689
int b[6]
Definition: codec_g726.c:83
int a[2]
Definition: codec_g726.c:81
int sr[2]
Definition: codec_g726.c:90
int dq[6]
Definition: codec_g726.c:87
int pk[2]
Definition: codec_g726.c:85
Definition: ast_expr2.c:325
static struct test_val d
Support for translation of data formats. translate.c.
#define ast_register_translator(t)
See __ast_register_translator()
Definition: translate.h:258
int ast_unregister_translator(struct ast_translator *t)
Unregister a translator Unregisters the given translator.
Definition: translate.c:1350
Utility functions.