|
5
|
1 /*
|
|
|
2 * SpanDSP - a series of DSP components for telephony
|
|
|
3 *
|
|
|
4 * lpc10_decode.c - LPC10 low bit rate speech codec.
|
|
|
5 *
|
|
|
6 * Written by Steve Underwood <steveu@coppice.org>
|
|
|
7 *
|
|
|
8 * Copyright (C) 2006 Steve Underwood
|
|
|
9 *
|
|
|
10 * All rights reserved.
|
|
|
11 *
|
|
|
12 * This program is free software; you can redistribute it and/or modify
|
|
|
13 * it under the terms of the GNU General Public License version 2, as
|
|
|
14 * published by the Free Software Foundation.
|
|
|
15 *
|
|
|
16 * This program is distributed in the hope that it will be useful,
|
|
|
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
19 * GNU General Public License for more details.
|
|
|
20 *
|
|
|
21 * You should have received a copy of the GNU General Public License
|
|
|
22 * along with this program; if not, write to the Free Software
|
|
|
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
|
24 *
|
|
|
25 * This code is based on the U.S. Department of Defense reference
|
|
|
26 * implementation of the LPC-10 2400 bps Voice Coder. They do not
|
|
|
27 * exert copyright claims on their code, and it may be freely used.
|
|
|
28 *
|
|
|
29 * $Id: lpc10_decode.c,v 1.14 2006/11/30 15:41:47 steveu Exp $
|
|
|
30 */
|
|
|
31
|
|
|
32 #ifdef HAVE_CONFIG_H
|
|
|
33 #include <config.h>
|
|
|
34 #endif
|
|
|
35
|
|
|
36 #include <stdlib.h>
|
|
|
37 #include <stdio.h>
|
|
|
38 #include <inttypes.h>
|
|
|
39 #if defined(HAVE_TGMATH_H)
|
|
|
40 #include <tgmath.h>
|
|
|
41 #endif
|
|
|
42 #if defined(HAVE_MATH_H)
|
|
|
43 #include <math.h>
|
|
|
44 #endif
|
|
|
45 #include <memory.h>
|
|
|
46
|
|
|
47 #include "spandsp/telephony.h"
|
|
|
48 #include "spandsp/dc_restore.h"
|
|
|
49 #include "spandsp/lpc10.h"
|
|
|
50
|
|
|
51 #define LPC10_ORDER 10
|
|
|
52
|
|
|
53 #define min(a,b) ((a) <= (b) ? (a) : (b))
|
|
|
54 #define max(a,b) ((a) >= (b) ? (a) : (b))
|
|
|
55
|
|
|
56 /* Pseudo random number generator based on Knuth, Vol 2, p. 27. */
|
|
|
57 /* lpc10_random - int32_t variable, uniformly distributed over -32768 to 32767 */
|
|
|
58 static int32_t lpc10_random(lpc10_decode_state_t *s)
|
|
|
59 {
|
|
|
60 int32_t ret_val;
|
|
|
61
|
|
|
62 /* The following is a 16 bit 2's complement addition,
|
|
|
63 with overflow checking disabled */
|
|
|
64 s->y[s->k] += s->y[s->j];
|
|
|
65 ret_val = s->y[s->k];
|
|
|
66 if (--s->k < 0)
|
|
|
67 s->k = 4;
|
|
|
68 if (--s->j < 0)
|
|
|
69 s->j = 4;
|
|
|
70 return ret_val;
|
|
|
71 }
|
|
|
72 /*- End of function --------------------------------------------------------*/
|
|
|
73
|
|
|
74 static __inline__ int32_t pow_ii(int32_t x, int32_t n)
|
|
|
75 {
|
|
|
76 int32_t pow;
|
|
|
77 uint32_t u;
|
|
|
78
|
|
|
79 if (n <= 0)
|
|
|
80 {
|
|
|
81 if (n == 0 || x == 1)
|
|
|
82 return 1;
|
|
|
83 if (x != -1)
|
|
|
84 return (x == 0) ? 1/x : 0;
|
|
|
85 n = -n;
|
|
|
86 }
|
|
|
87 u = n;
|
|
|
88 for (pow = 1; ; )
|
|
|
89 {
|
|
|
90 if ((u & 1))
|
|
|
91 pow *= x;
|
|
|
92 if ((u >>= 1) == 0)
|
|
|
93 break;
|
|
|
94 x *= x;
|
|
|
95 }
|
|
|
96 return pow;
|
|
|
97 }
|
|
|
98 /*- End of function --------------------------------------------------------*/
|
|
|
99
|
|
|
100 /* Synthesize one pitch epoch */
|
|
|
101 static void bsynz(lpc10_decode_state_t *s,
|
|
|
102 float coef[],
|
|
|
103 int32_t ip,
|
|
|
104 int32_t *iv,
|
|
|
105 float sout[],
|
|
|
106 float rms,
|
|
|
107 float ratio,
|
|
|
108 float g2pass)
|
|
|
109 {
|
|
|
110 static const int32_t kexc[25] =
|
|
|
111 {
|
|
|
112 8, -16, 26, -48, 86, -162, 294, -502, 718, -728, 184,
|
|
|
113 672, -610, -672, 184, 728, 718, 502, 294, 162, 86, 48, 26, 16, 8
|
|
|
114 };
|
|
|
115 int32_t i;
|
|
|
116 int32_t j;
|
|
|
117 int32_t k;
|
|
|
118 int32_t px;
|
|
|
119 float noise[166];
|
|
|
120 float pulse;
|
|
|
121 float r1;
|
|
|
122 float gain;
|
|
|
123 float xssq;
|
|
|
124 float sscale;
|
|
|
125 float xy;
|
|
|
126 float sum;
|
|
|
127 float ssq;
|
|
|
128 float lpi0;
|
|
|
129 float hpi0;
|
|
|
130
|
|
|
131 /* MAXPIT + MAXORD = 166 */
|
|
|
132 /* Calculate history scale factor XY and scale filter state */
|
|
|
133 /* Computing MIN */
|
|
|
134 r1 = s->rmso_bsynz/(rms + 1.0e-6f);
|
|
|
135 xy = min(r1, 8.0f);
|
|
|
136 s->rmso_bsynz = rms;
|
|
|
137 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
138 s->exc2[i] = s->exc2[s->ipo + i]*xy;
|
|
|
139 s->ipo = ip;
|
|
|
140 if (*iv == 0)
|
|
|
141 {
|
|
|
142 /* Generate white noise for unvoiced */
|
|
|
143 for (i = 0; i < ip; i++)
|
|
|
144 s->exc[LPC10_ORDER + i] = (float) (lpc10_random(s)/64);
|
|
|
145 /* Impulse double excitation for plosives */
|
|
|
146 px = (lpc10_random(s) + 32768)*(ip - 1)/65536 + LPC10_ORDER + 1;
|
|
|
147 r1 = ratio/4.0f;
|
|
|
148 pulse = r1*342;
|
|
|
149 if (pulse > 2.0e3f)
|
|
|
150 pulse = 2.0e3f;
|
|
|
151 s->exc[px - 1] += pulse;
|
|
|
152 s->exc[px] -= pulse;
|
|
|
153 }
|
|
|
154 else
|
|
|
155 {
|
|
|
156 sscale = sqrtf((float) ip)/6.928f;
|
|
|
157 for (i = 0; i < ip; i++)
|
|
|
158 {
|
|
|
159 s->exc[LPC10_ORDER + i] = 0.0f;
|
|
|
160 if (i < 25)
|
|
|
161 s->exc[LPC10_ORDER + i] = sscale*kexc[i];
|
|
|
162 lpi0 = s->exc[LPC10_ORDER + i];
|
|
|
163 s->exc[LPC10_ORDER + i] = s->exc[LPC10_ORDER + i]*0.125f + s->lpi[0]*0.75f + s->lpi[1]*0.125f;
|
|
|
164 s->lpi[1] = s->lpi[0];
|
|
|
165 s->lpi[0] = lpi0;
|
|
|
166 }
|
|
|
167 for (i = 0; i < ip; i++)
|
|
|
168 {
|
|
|
169 noise[LPC10_ORDER + i] = lpc10_random(s)/64.0f;
|
|
|
170 hpi0 = noise[LPC10_ORDER + i];
|
|
|
171 noise[LPC10_ORDER + i] = noise[LPC10_ORDER + i]*-0.125f + s->hpi[0]*0.25f + s->hpi[1]*-0.125f;
|
|
|
172 s->hpi[1] = s->hpi[0];
|
|
|
173 s->hpi[0] = hpi0;
|
|
|
174 }
|
|
|
175 for (i = 0; i < ip; i++)
|
|
|
176 s->exc[LPC10_ORDER + i] += noise[LPC10_ORDER + i];
|
|
|
177 }
|
|
|
178 /* Synthesis filters: */
|
|
|
179 /* Modify the excitation with all-zero filter 1 + G*SUM */
|
|
|
180 xssq = 0.0f;
|
|
|
181 for (i = 0; i < ip; i++)
|
|
|
182 {
|
|
|
183 k = LPC10_ORDER + i;
|
|
|
184 sum = 0.0f;
|
|
|
185 for (j = 0; j < LPC10_ORDER; j++)
|
|
|
186 sum += coef[j]*s->exc[k - j - 1];
|
|
|
187 sum *= g2pass;
|
|
|
188 s->exc2[k] = sum + s->exc[k];
|
|
|
189 }
|
|
|
190 /* Synthesize using the all pole filter 1/(1 - SUM) */
|
|
|
191 for (i = 0; i < ip; i++)
|
|
|
192 {
|
|
|
193 k = LPC10_ORDER + i;
|
|
|
194 sum = 0.0f;
|
|
|
195 for (j = 0; j < LPC10_ORDER; j++)
|
|
|
196 sum += coef[j]*s->exc2[k - j - 1];
|
|
|
197 s->exc2[k] = sum + s->exc2[k];
|
|
|
198 xssq += s->exc2[k]*s->exc2[k];
|
|
|
199 }
|
|
|
200 /* Save filter history for next epoch */
|
|
|
201 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
202 {
|
|
|
203 s->exc[i] = s->exc[ip + i];
|
|
|
204 s->exc2[i] = s->exc2[ip + i];
|
|
|
205 }
|
|
|
206 /* Apply gain to match RMS */
|
|
|
207 ssq = rms*rms*ip;
|
|
|
208 gain = sqrtf(ssq/xssq);
|
|
|
209 for (i = 0; i < ip; i++)
|
|
|
210 sout[i] = gain*s->exc2[LPC10_ORDER + i];
|
|
|
211 }
|
|
|
212 /*- End of function --------------------------------------------------------*/
|
|
|
213
|
|
|
214 /* Synthesize a single pitch epoch */
|
|
|
215 static int pitsyn(lpc10_decode_state_t *s,
|
|
|
216 int voice[],
|
|
|
217 int32_t *pitch,
|
|
|
218 float *rms,
|
|
|
219 float *rc,
|
|
|
220 int32_t ivuv[],
|
|
|
221 int32_t ipiti[],
|
|
|
222 float *rmsi,
|
|
|
223 float *rci,
|
|
|
224 int32_t *nout,
|
|
|
225 float *ratio)
|
|
|
226 {
|
|
|
227 int32_t rci_dim1;
|
|
|
228 int32_t rci_offset;
|
|
|
229 int32_t i1;
|
|
|
230 int32_t i;
|
|
|
231 int32_t j;
|
|
|
232 int32_t vflag;
|
|
|
233 int32_t jused;
|
|
|
234 int32_t lsamp;
|
|
|
235 int32_t ip;
|
|
|
236 int32_t nl;
|
|
|
237 int32_t ivoice;
|
|
|
238 int32_t istart;
|
|
|
239 float r1;
|
|
|
240 float alrn;
|
|
|
241 float alro;
|
|
|
242 float yarc[10];
|
|
|
243 float prop;
|
|
|
244 float slope;
|
|
|
245 float uvpit;
|
|
|
246 float xxy;
|
|
|
247
|
|
|
248 rci_dim1 = LPC10_ORDER;
|
|
|
249 rci_offset = rci_dim1 + 1;
|
|
|
250 rci -= rci_offset;
|
|
|
251
|
|
|
252 if (*rms < 1.0f)
|
|
|
253 *rms = 1.0f;
|
|
|
254 if (s->rmso < 1.0f)
|
|
|
255 s->rmso = 1.0f;
|
|
|
256 uvpit = 0.0f;
|
|
|
257 *ratio = *rms/(s->rmso + 8.0f);
|
|
|
258 if (s->first_pitsyn)
|
|
|
259 {
|
|
|
260 lsamp = 0;
|
|
|
261 ivoice = voice[1];
|
|
|
262 if (ivoice == 0)
|
|
|
263 *pitch = LPC10_SAMPLES_PER_FRAME/4;
|
|
|
264 *nout = LPC10_SAMPLES_PER_FRAME / *pitch;
|
|
|
265 s->jsamp = LPC10_SAMPLES_PER_FRAME - *nout * *pitch;
|
|
|
266
|
|
|
267 i1 = *nout;
|
|
|
268 for (i = 0; i < i1; i++)
|
|
|
269 {
|
|
|
270 for (j = 0; j < LPC10_ORDER; j++)
|
|
|
271 rci[j + (i + 1)*rci_dim1 + 1] = rc[j];
|
|
|
272 ivuv[i] = ivoice;
|
|
|
273 ipiti[i] = *pitch;
|
|
|
274 rmsi[i] = *rms;
|
|
|
275 }
|
|
|
276 s->first_pitsyn = FALSE;
|
|
|
277 }
|
|
|
278 else
|
|
|
279 {
|
|
|
280 vflag = 0;
|
|
|
281 lsamp = LPC10_SAMPLES_PER_FRAME + s->jsamp;
|
|
|
282 slope = (*pitch - s->ipito)/(float) lsamp;
|
|
|
283 *nout = 0;
|
|
|
284 jused = 0;
|
|
|
285 istart = 1;
|
|
|
286 if (voice[0] == s->ivoico && voice[1] == voice[0])
|
|
|
287 {
|
|
|
288 if (voice[1] == 0)
|
|
|
289 {
|
|
|
290 /* SSUV - - 0 , 0 , 0 */
|
|
|
291 *pitch = LPC10_SAMPLES_PER_FRAME/4;
|
|
|
292 s->ipito = *pitch;
|
|
|
293 if (*ratio > 8.0f)
|
|
|
294 s->rmso = *rms;
|
|
|
295 }
|
|
|
296 /* SSVC - - 1 , 1 , 1 */
|
|
|
297 slope = (*pitch - s->ipito)/(float) lsamp;
|
|
|
298 ivoice = voice[1];
|
|
|
299 }
|
|
|
300 else
|
|
|
301 {
|
|
|
302 if (s->ivoico != 1)
|
|
|
303 {
|
|
|
304 if (s->ivoico == voice[0])
|
|
|
305 {
|
|
|
306 /* UV2VC2 - - 0 , 0 , 1 */
|
|
|
307 nl = lsamp - LPC10_SAMPLES_PER_FRAME/4;
|
|
|
308 }
|
|
|
309 else
|
|
|
310 {
|
|
|
311 /* UV2VC1 - - 0 , 1 , 1 */
|
|
|
312 nl = lsamp - LPC10_SAMPLES_PER_FRAME*3/4;
|
|
|
313 }
|
|
|
314 ipiti[0] = nl/2;
|
|
|
315 ipiti[1] = nl - ipiti[0];
|
|
|
316 ivuv[0] = 0;
|
|
|
317 ivuv[1] = 0;
|
|
|
318 rmsi[0] = s->rmso;
|
|
|
319 rmsi[1] = s->rmso;
|
|
|
320 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
321 {
|
|
|
322 rci[i + rci_dim1 + 1] = s->rco[i];
|
|
|
323 rci[i + (rci_dim1 << 1) + 1] = s->rco[i];
|
|
|
324 s->rco[i] = rc[i];
|
|
|
325 }
|
|
|
326 slope = 0.0f;
|
|
|
327 *nout = 2;
|
|
|
328 s->ipito = *pitch;
|
|
|
329 jused = nl;
|
|
|
330 istart = nl + 1;
|
|
|
331 ivoice = 1;
|
|
|
332 }
|
|
|
333 else
|
|
|
334 {
|
|
|
335 if (s->ivoico != voice[0])
|
|
|
336 {
|
|
|
337 /* VC2UV1 - - 1 , 0 , 0 */
|
|
|
338 lsamp = LPC10_SAMPLES_PER_FRAME/4 + s->jsamp;
|
|
|
339 }
|
|
|
340 else
|
|
|
341 {
|
|
|
342 /* VC2UV2 - - 1 , 1 , 0 */
|
|
|
343 lsamp = LPC10_SAMPLES_PER_FRAME*3/4 + s->jsamp;
|
|
|
344 }
|
|
|
345 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
346 {
|
|
|
347 yarc[i] = rc[i];
|
|
|
348 rc[i] = s->rco[i];
|
|
|
349 }
|
|
|
350 ivoice = 1;
|
|
|
351 slope = 0.0f;
|
|
|
352 vflag = 1;
|
|
|
353 }
|
|
|
354 }
|
|
|
355 /* Here is the value of most variables that are used below, depending on */
|
|
|
356 /* the values of IVOICO, VOICE(1), and VOICE(2). VOICE(1) and VOICE(2) */
|
|
|
357 /* are input arguments, and IVOICO is the value of VOICE(2) on the */
|
|
|
358 /* previous call (see notes for the IF (NOUT .NE. 0) statement near the */
|
|
|
359 /* end). Each of these three values is either 0 or 1. These three */
|
|
|
360 /* values below are given as 3-bit long strings, in the order IVOICO, */
|
|
|
361 /* VOICE(1), and VOICE(2). It appears that the code above assumes that */
|
|
|
362 /* the bit sequences 010 and 101 never occur, but I wonder whether a */
|
|
|
363 /* large enough number of bit errors in the channel could cause such a */
|
|
|
364 /* thing to happen, and if so, could that cause NOUT to ever go over 11? */
|
|
|
365
|
|
|
366 /* Note that all of the 180 values in the table are floatly LFRAME, but */
|
|
|
367 /* 180 has fewer characters, and it makes the table a little more */
|
|
|
368 /* concrete. If LFRAME is ever changed, keep this in mind. Similarly, */
|
|
|
369 /* 135's are 3*LFRAME/4, and 45's are LFRAME/4. If LFRAME is not a */
|
|
|
370 /* multiple of 4, then the 135 for NL-JSAMP is actually LFRAME-LFRAME/4, */
|
|
|
371 /* and the 45 for NL-JSAMP is actually LFRAME-3*LFRAME/4. */
|
|
|
372
|
|
|
373 /* Note that LSAMP-JSAMP is given as the variable. This was just for */
|
|
|
374 /* brevity, to avoid adding "+JSAMP" to all of the column entries. */
|
|
|
375 /* Similarly for NL-JSAMP. */
|
|
|
376
|
|
|
377 /* Variable | 000 001 011,010 111 110 100,101 */
|
|
|
378 /* ------------+-------------------------------------------------- */
|
|
|
379 /* ISTART | 1 NL+1 NL+1 1 1 1 */
|
|
|
380 /* LSAMP-JSAMP | 180 180 180 180 135 45 */
|
|
|
381 /* IPITO | 45 PITCH PITCH oldPITCH oldPITCH oldPITCH */
|
|
|
382 /* SLOPE | 0 0 0 seebelow 0 0 */
|
|
|
383 /* JUSED | 0 NL NL 0 0 0 */
|
|
|
384 /* PITCH | 45 PITCH PITCH PITCH PITCH PITCH */
|
|
|
385 /* NL-JSAMP | -- 135 45 -- -- -- */
|
|
|
386 /* VFLAG | 0 0 0 0 1 1 */
|
|
|
387 /* NOUT | 0 2 2 0 0 0 */
|
|
|
388 /* IVOICE | 0 1 1 1 1 1 */
|
|
|
389
|
|
|
390 /* while_loop | once once once once twice twice */
|
|
|
391
|
|
|
392 /* ISTART | -- -- -- -- JUSED+1 JUSED+1 */
|
|
|
393 /* LSAMP-JSAMP | -- -- -- -- 180 180 */
|
|
|
394 /* IPITO | -- -- -- -- oldPITCH oldPITCH */
|
|
|
395 /* SLOPE | -- -- -- -- 0 0 */
|
|
|
396 /* JUSED | -- -- -- -- ?? ?? */
|
|
|
397 /* PITCH | -- -- -- -- PITCH PITCH */
|
|
|
398 /* NL-JSAMP | -- -- -- -- -- -- */
|
|
|
399 /* VFLAG | -- -- -- -- 0 0 */
|
|
|
400 /* NOUT | -- -- -- -- ?? ?? */
|
|
|
401 /* IVOICE | -- -- -- -- 0 0 */
|
|
|
402
|
|
|
403 /* UVPIT is always 0.0 on the first pass through the DO WHILE (TRUE)
|
|
|
404 loop below. */
|
|
|
405
|
|
|
406 /* The only possible non-0 value of SLOPE (in column 111) is
|
|
|
407 (PITCH-IPITO)/FLOAT(LSAMP) */
|
|
|
408
|
|
|
409 /* Column 101 is identical to 100. Any good properties we can prove
|
|
|
410 for 100 will also hold for 101. Similarly for 010 and 011. */
|
|
|
411
|
|
|
412 /* synths() calls this subroutine with PITCH restricted to the range 20 to
|
|
|
413 156. IPITO is similarly restricted to this range, after the first
|
|
|
414 call. IP below is also restricted to this range, given the
|
|
|
415 definitions of IPITO, SLOPE, UVPIT, and that I is in the range ISTART
|
|
|
416 to LSAMP. */
|
|
|
417
|
|
|
418 for (;;)
|
|
|
419 {
|
|
|
420 for (i = istart; i <= lsamp; i++)
|
|
|
421 {
|
|
|
422 r1 = s->ipito + slope*i;
|
|
|
423 ip = r1 + 0.5f;
|
|
|
424 if (uvpit != 0.0f)
|
|
|
425 ip = uvpit;
|
|
|
426 if (ip <= i - jused)
|
|
|
427 {
|
|
|
428 ++(*nout);
|
|
|
429 ipiti[*nout - 1] = ip;
|
|
|
430 *pitch = ip;
|
|
|
431 ivuv[*nout - 1] = ivoice;
|
|
|
432 jused += ip;
|
|
|
433 prop = (jused - ip/2)/(float) lsamp;
|
|
|
434 for (j = 0; j < LPC10_ORDER; j++)
|
|
|
435 {
|
|
|
436 alro = log((s->rco[j] + 1)/(1 - s->rco[j]));
|
|
|
437 alrn = log((rc[j] + 1)/(1 - rc[j]));
|
|
|
438 xxy = alro + prop*(alrn - alro);
|
|
|
439 xxy = expf(xxy);
|
|
|
440 rci[j + *nout*rci_dim1 + 1] = (xxy - 1.0f)/(xxy + 1.0f);
|
|
|
441 }
|
|
|
442 rmsi[*nout - 1] = logf(s->rmso) + prop*(logf(*rms) - logf(s->rmso));
|
|
|
443 rmsi[*nout - 1] = expf(rmsi[*nout - 1]);
|
|
|
444 }
|
|
|
445 }
|
|
|
446 if (vflag != 1)
|
|
|
447 break;
|
|
|
448
|
|
|
449 vflag = 0;
|
|
|
450 istart = jused + 1;
|
|
|
451 lsamp = LPC10_SAMPLES_PER_FRAME + s->jsamp;
|
|
|
452 slope = 0.0f;
|
|
|
453 ivoice = 0;
|
|
|
454 uvpit = (float) ((lsamp - istart)/2);
|
|
|
455 if (uvpit > 90.0f)
|
|
|
456 uvpit /= 2;
|
|
|
457 s->rmso = *rms;
|
|
|
458 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
459 {
|
|
|
460 rc[i] = yarc[i];
|
|
|
461 s->rco[i] = yarc[i];
|
|
|
462 }
|
|
|
463 }
|
|
|
464 s->jsamp = lsamp - jused;
|
|
|
465 }
|
|
|
466 if (*nout != 0)
|
|
|
467 {
|
|
|
468 s->ivoico = voice[1];
|
|
|
469 s->ipito = *pitch;
|
|
|
470 s->rmso = *rms;
|
|
|
471 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
472 s->rco[i] = rc[i];
|
|
|
473 }
|
|
|
474 return 0;
|
|
|
475 }
|
|
|
476 /*- End of function --------------------------------------------------------*/
|
|
|
477
|
|
|
478 static void deemp(lpc10_decode_state_t *s, float x[], int len)
|
|
|
479 {
|
|
|
480 int i;
|
|
|
481 float r1;
|
|
|
482 float dei0;
|
|
|
483
|
|
|
484 for (i = 0; i < len; i++)
|
|
|
485 {
|
|
|
486 dei0 = x[i];
|
|
|
487 r1 = x[i] - s->dei[0]*1.9998f + s->dei[1];
|
|
|
488 x[i] = r1 + s->deo[0]*2.5f - s->deo[1]*2.0925f + s->deo[2]*0.585f;
|
|
|
489 s->dei[1] = s->dei[0];
|
|
|
490 s->dei[0] = dei0;
|
|
|
491 s->deo[2] = s->deo[1];
|
|
|
492 s->deo[1] = s->deo[0];
|
|
|
493 s->deo[0] = x[i];
|
|
|
494 }
|
|
|
495 }
|
|
|
496 /*- End of function --------------------------------------------------------*/
|
|
|
497
|
|
|
498 /* Convert reflection coefficients to predictor coefficients */
|
|
|
499 static float reflection_coeffs_to_predictor_coeffs(float rc[], float pc[], float gprime)
|
|
|
500 {
|
|
|
501 float temp[10];
|
|
|
502 float g2pass;
|
|
|
503 int i;
|
|
|
504 int j;
|
|
|
505
|
|
|
506 g2pass = 1.0f;
|
|
|
507 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
508 g2pass *= 1.0f - rc[i]*rc[i];
|
|
|
509 g2pass = gprime*sqrtf(g2pass);
|
|
|
510 pc[0] = rc[0];
|
|
|
511 for (i = 1; i < LPC10_ORDER; i++)
|
|
|
512 {
|
|
|
513 for (j = 0; j < i; j++)
|
|
|
514 temp[j] = pc[j] - rc[i]*pc[i - j - 1];
|
|
|
515 for (j = 0; j < i; j++)
|
|
|
516 pc[j] = temp[j];
|
|
|
517 pc[i] = rc[i];
|
|
|
518 }
|
|
|
519 return g2pass;
|
|
|
520 }
|
|
|
521 /*- End of function --------------------------------------------------------*/
|
|
|
522
|
|
|
523 static int synths(lpc10_decode_state_t *s,
|
|
|
524 int voice[],
|
|
|
525 int32_t *pitch,
|
|
|
526 float *rms,
|
|
|
527 float *rc,
|
|
|
528 float speech[])
|
|
|
529 {
|
|
|
530 int32_t i1;
|
|
|
531 int32_t ivuv[16];
|
|
|
532 int32_t ipiti[16];
|
|
|
533 int32_t nout;
|
|
|
534 int32_t i;
|
|
|
535 int32_t j;
|
|
|
536 float rmsi[16];
|
|
|
537 float ratio;
|
|
|
538 float g2pass;
|
|
|
539 float pc[10];
|
|
|
540 float rci[160];
|
|
|
541
|
|
|
542 i1 = min(*pitch, 156);
|
|
|
543 *pitch = max(i1, 20);
|
|
|
544 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
545 rc[i] = max(min(rc[i], 0.99f), -0.99f);
|
|
|
546 pitsyn(s, voice, pitch, rms, rc, ivuv, ipiti, rmsi, rci, &nout, &ratio);
|
|
|
547 if (nout > 0)
|
|
|
548 {
|
|
|
549 for (j = 0; j < nout; j++)
|
|
|
550 {
|
|
|
551 /* Add synthesized speech for pitch period J to the end of s->buf. */
|
|
|
552 g2pass = reflection_coeffs_to_predictor_coeffs(&rci[j*10], pc, 0.7f);
|
|
|
553 bsynz(s, pc, ipiti[j], &ivuv[j], &s->buf[s->buflen], rmsi[j], ratio, g2pass);
|
|
|
554 deemp(s, &s->buf[s->buflen], ipiti[j]);
|
|
|
555 s->buflen += ipiti[j];
|
|
|
556 }
|
|
|
557 /* Copy first MAXFRM samples from BUF to output array speech (scaling them),
|
|
|
558 and then remove them from the beginning of s->buf. */
|
|
|
559
|
|
|
560 for (i = 0; i < LPC10_SAMPLES_PER_FRAME; i++)
|
|
|
561 speech[i] = s->buf[i]/4096.0f;
|
|
|
562 s->buflen -= LPC10_SAMPLES_PER_FRAME;
|
|
|
563 for (i = 0; i < s->buflen; i++)
|
|
|
564 s->buf[i] = s->buf[i + LPC10_SAMPLES_PER_FRAME];
|
|
|
565 }
|
|
|
566 return 0;
|
|
|
567 }
|
|
|
568 /*- End of function --------------------------------------------------------*/
|
|
|
569
|
|
|
570 static void lpc10_unpack(lpc10_frame_t *t, const uint8_t ibits[])
|
|
|
571 {
|
|
|
572 static const int bit[10] =
|
|
|
573 {
|
|
|
574 2, 4, 8, 8, 8, 8, 16, 16, 16, 16
|
|
|
575 };
|
|
|
576 static const int iblist[53] =
|
|
|
577 {
|
|
|
578 13, 12, 11, 1, 2, 13, 12, 11, 1, 2,
|
|
|
579 13, 10, 11, 2, 1, 10, 13, 12, 11, 10,
|
|
|
580 2, 13, 12, 11, 10, 2, 1, 12, 7, 6,
|
|
|
581 1, 10, 9, 8, 7, 4, 6, 9, 8, 7,
|
|
|
582 5, 1, 9, 8, 4, 6, 1, 5, 9, 8,
|
|
|
583 7, 5, 6
|
|
|
584 };
|
|
|
585 int32_t itab[13];
|
|
|
586 int x;
|
|
|
587 int i;
|
|
|
588
|
|
|
589 /* ibits is 54 bits of LPC data ordered as follows: */
|
|
|
590 /* R1-0, R2-0, R3-0, P-0, A-0, */
|
|
|
591 /* R1-1, R2-1, R3-1, P-1, A-1, */
|
|
|
592 /* R1-2, R4-0, R3-2, A-2, P-2, R4-1, */
|
|
|
593 /* R1-3, R2-2, R3-3, R4-2, A-3, */
|
|
|
594 /* R1-4, R2-3, R3-4, R4-3, A-4, */
|
|
|
595 /* P-3, R2-4, R7-0, R8-0, P-4, R4-4, */
|
|
|
596 /* R5-0, R6-0, R7-1,R10-0, R8-1, */
|
|
|
597 /* R5-1, R6-1, R7-2, R9-0, P-5, */
|
|
|
598 /* R5-2, R6-2,R10-1, R8-2, P-6, R9-1, */
|
|
|
599 /* R5-3, R6-3, R7-3, R9-2, R8-3, SYNC */
|
|
|
600
|
|
|
601 /* Reconstruct ITAB */
|
|
|
602 for (i = 0; i < 13; i++)
|
|
|
603 itab[i] = 0;
|
|
|
604 for (i = 0; i < 53; i++)
|
|
|
605 {
|
|
|
606 x = 52 - i;
|
|
|
607 x = (ibits[x >> 3] >> (7 - (x & 7))) & 1;
|
|
|
608 itab[iblist[52 - i] - 1] = (itab[iblist[52 - i] - 1] << 1) | x;
|
|
|
609 }
|
|
|
610 /* Sign extend the RC's */
|
|
|
611 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
612 {
|
|
|
613 if ((itab[i + 3] & bit[i]))
|
|
|
614 itab[i + 3] -= (bit[i] << 1);
|
|
|
615 }
|
|
|
616 /* Restore variables */
|
|
|
617 t->ipitch = itab[0];
|
|
|
618 t->irms = itab[1];
|
|
|
619 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
620 t->irc[i] = itab[LPC10_ORDER - 1 - i + 3];
|
|
|
621 }
|
|
|
622 /*- End of function --------------------------------------------------------*/
|
|
|
623
|
|
|
624 /* Hamming 8, 4 decoder - can correct 1 out of seven bits
|
|
|
625 and can detect up to two errors. */
|
|
|
626
|
|
|
627 /* This subroutine is entered with an eight bit word in INPUT. The 8th */
|
|
|
628 /* bit is parity and is stripped off. The remaining 7 bits address the */
|
|
|
629 /* hamming 8, 4 table and the output OUTPUT from the table gives the 4 */
|
|
|
630 /* bits of corrected data. If bit 4 is set, no error was detected. */
|
|
|
631 /* ERRCNT is the number of errors counted. */
|
|
|
632
|
|
|
633 static int32_t hamming_84_decode(int32_t input, int *errcnt)
|
|
|
634 {
|
|
|
635 static const uint8_t dactab[128] =
|
|
|
636 {
|
|
|
637 16, 0, 0, 3, 0, 5, 14, 7, 0, 9, 14, 11, 14, 13, 30, 14,
|
|
|
638 0, 9, 2, 7, 4, 7, 7, 23, 9, 25, 10, 9, 12, 9, 14, 7,
|
|
|
639 0, 5, 2, 11, 5, 21, 6, 5, 8, 11, 11, 27, 12, 5, 14, 11,
|
|
|
640 2, 1, 18, 2, 12, 5, 2, 7, 12, 9, 2, 11, 28, 12, 12, 15,
|
|
|
641 0, 3, 3, 19, 4, 13, 6, 3, 8, 13, 10, 3, 13, 29, 14, 13,
|
|
|
642 4, 1, 10, 3, 20, 4, 4, 7, 10, 9, 26, 10, 4, 13, 10, 15,
|
|
|
643 8, 1, 6, 3, 6, 5, 22, 6, 24, 8, 8, 11, 8, 13, 6, 15,
|
|
|
644 1, 17 , 2, 1, 4, 1, 6, 15, 8, 1, 10, 15, 12, 15, 15, 31
|
|
|
645 };
|
|
|
646 int i;
|
|
|
647 int parity;
|
|
|
648 int32_t output;
|
|
|
649
|
|
|
650 parity = input & 255;
|
|
|
651 parity ^= parity >> 4;
|
|
|
652 parity ^= parity >> 2;
|
|
|
653 parity ^= parity >> 1;
|
|
|
654 parity &= 1;
|
|
|
655 i = dactab[input & 127];
|
|
|
656 output = i & 15;
|
|
|
657 if ((i & 16))
|
|
|
658 {
|
|
|
659 /* No errors detected in seven bits */
|
|
|
660 if (parity)
|
|
|
661 (*errcnt)++;
|
|
|
662 }
|
|
|
663 else
|
|
|
664 {
|
|
|
665 /* One or two errors detected */
|
|
|
666 (*errcnt)++;
|
|
|
667 if (parity == 0)
|
|
|
668 {
|
|
|
669 /* Two errors detected */
|
|
|
670 (*errcnt)++;
|
|
|
671 output = -1;
|
|
|
672 }
|
|
|
673 }
|
|
|
674 return output;
|
|
|
675 }
|
|
|
676 /*- End of function --------------------------------------------------------*/
|
|
|
677
|
|
|
678 static int32_t median(int32_t d1, int32_t d2, int32_t d3)
|
|
|
679 {
|
|
|
680 int32_t ret_val;
|
|
|
681
|
|
|
682 ret_val = d2;
|
|
|
683 if (d2 > d1 && d2 > d3)
|
|
|
684 {
|
|
|
685 ret_val = d1;
|
|
|
686 if (d3 > d1)
|
|
|
687 ret_val = d3;
|
|
|
688 }
|
|
|
689 else if (d2 < d1 && d2 < d3)
|
|
|
690 {
|
|
|
691 ret_val = d1;
|
|
|
692 if (d3 < d1)
|
|
|
693 ret_val = d3;
|
|
|
694 }
|
|
|
695 return ret_val;
|
|
|
696 }
|
|
|
697 /*- End of function --------------------------------------------------------*/
|
|
|
698
|
|
|
699 static void decode(lpc10_decode_state_t *s,
|
|
|
700 lpc10_frame_t *t,
|
|
|
701 int voice[],
|
|
|
702 int32_t *pitch,
|
|
|
703 float *rms,
|
|
|
704 float rc[])
|
|
|
705 {
|
|
|
706 static const int32_t ivtab[32] =
|
|
|
707 {
|
|
|
708 24960, 24960, 24960, 24960, 25480, 25480, 25483, 25480,
|
|
|
709 16640, 1560, 1560, 1560, 16640, 1816, 1563, 1560,
|
|
|
710 24960, 24960, 24859, 24856, 26001, 25881, 25915, 25913,
|
|
|
711 1560, 1560, 7800, 3640, 1561, 1561, 3643, 3641
|
|
|
712 };
|
|
|
713 static const float corth[32] =
|
|
|
714 {
|
|
|
715 32767.0f, 10.0f, 5.0f, 0.0f, 32767.0f, 8.0f, 4.0f, 0.0f,
|
|
|
716 32.0f, 6.4f, 3.2f, 0.0f, 32.0f, 6.4f, 3.2f, 0.0f,
|
|
|
717 32.0f, 11.2f, 6.4f, 0.0f, 32.0f, 11.2f, 6.4f, 0.0f,
|
|
|
718 16.0f, 5.6f, 3.2f, 0.0f, 16.0f, 5.6f, 3.2f, 0.0f
|
|
|
719 };
|
|
|
720 static const int32_t detau[128] =
|
|
|
721 {
|
|
|
722 0, 0, 0, 3, 0, 3, 3, 31,
|
|
|
723 0, 3, 3, 21, 3, 3, 29, 30,
|
|
|
724 0, 3, 3, 20, 3, 25, 27, 26,
|
|
|
725 3, 23, 58, 22, 3, 24, 28, 3,
|
|
|
726 0, 3, 3, 3, 3, 39, 33, 32,
|
|
|
727 3, 37, 35, 36, 3, 38, 34, 3,
|
|
|
728 3, 42, 46, 44, 50, 40, 48, 3,
|
|
|
729 54, 3, 56, 3, 52, 3, 3, 1,
|
|
|
730 0, 3, 3, 108, 3, 78, 100, 104,
|
|
|
731 3, 84, 92, 88, 156, 80, 96, 3,
|
|
|
732 3, 74, 70, 72, 66, 76, 68, 3,
|
|
|
733 62, 3, 60, 3, 64, 3, 3, 1,
|
|
|
734 3, 116, 132, 112, 148, 152, 3, 3,
|
|
|
735 140, 3, 136, 3, 144, 3, 3, 1,
|
|
|
736 124, 120, 128, 3, 3, 3, 3, 1,
|
|
|
737 3, 3, 3, 1, 3, 1, 1, 1
|
|
|
738 };
|
|
|
739 static const int32_t rmst[64] =
|
|
|
740 {
|
|
|
741 1024, 936, 856, 784, 718, 656, 600, 550,
|
|
|
742 502, 460, 420, 384, 352, 328, 294, 270,
|
|
|
743 246, 226, 206, 188, 172, 158, 144, 132,
|
|
|
744 120, 110, 102, 92, 84, 78, 70, 64,
|
|
|
745 60, 54, 50, 46, 42, 38, 34, 32,
|
|
|
746 30, 26, 24, 22, 20, 18, 17, 16,
|
|
|
747 15, 14, 13, 12, 11, 10, 9, 8,
|
|
|
748 7, 6, 5, 4, 3, 2, 1, 0
|
|
|
749 };
|
|
|
750 static const int32_t detab7[32] =
|
|
|
751 {
|
|
|
752 4, 11, 18, 25, 32, 39, 46, 53,
|
|
|
753 60, 66, 72, 77, 82, 87, 92, 96,
|
|
|
754 101, 104, 108, 111, 114, 115, 117, 119,
|
|
|
755 121, 122, 123, 124, 125, 126, 127, 127
|
|
|
756 };
|
|
|
757 static const float descl[8] =
|
|
|
758 {
|
|
|
759 0.6953f, 0.625f, 0.5781f, 0.5469f, 0.5312f, 0.5391f, 0.4688f, 0.3828f
|
|
|
760 };
|
|
|
761 static const int32_t deadd[8] =
|
|
|
762 {
|
|
|
763 1152, -2816, -1536, -3584, -1280, -2432, 768, -1920
|
|
|
764 };
|
|
|
765 static const int32_t qb[8] =
|
|
|
766 {
|
|
|
767 511, 511, 1023, 1023, 1023, 1023, 2047, 4095
|
|
|
768 };
|
|
|
769 static const int32_t nbit[10] =
|
|
|
770 {
|
|
|
771 8, 8, 5, 5, 4, 4, 4, 4, 3, 2
|
|
|
772 };
|
|
|
773 static const int32_t zrc[10] =
|
|
|
774 {
|
|
|
775 0, 0, 0, 0, 0, 3, 0, 2, 0, 0
|
|
|
776 };
|
|
|
777 static const int32_t bit[5] =
|
|
|
778 {
|
|
|
779 2, 4, 8, 16, 32
|
|
|
780 };
|
|
|
781 int32_t ipit;
|
|
|
782 int32_t iout;
|
|
|
783 int32_t i;
|
|
|
784 int32_t icorf;
|
|
|
785 int32_t index;
|
|
|
786 int32_t ivoic;
|
|
|
787 int32_t ixcor;
|
|
|
788 int32_t i1;
|
|
|
789 int32_t i2;
|
|
|
790 int32_t i4;
|
|
|
791 int32_t ishift;
|
|
|
792 int32_t lsb;
|
|
|
793 int errcnt;
|
|
|
794
|
|
|
795 /* If no error correction, do pitch and voicing then jump to decode */
|
|
|
796 i4 = detau[t->ipitch];
|
|
|
797 if (!s->error_correction)
|
|
|
798 {
|
|
|
799 voice[0] = 1;
|
|
|
800 voice[1] = 1;
|
|
|
801 if (t->ipitch <= 1)
|
|
|
802 voice[0] = 0;
|
|
|
803 if (t->ipitch == 0 || t->ipitch == 2)
|
|
|
804 voice[1] = 0;
|
|
|
805 if (i4 <= 4)
|
|
|
806 i4 = s->iptold;
|
|
|
807 *pitch = i4;
|
|
|
808 if (voice[0] == 1 && voice[1] == 1)
|
|
|
809 s->iptold = *pitch;
|
|
|
810 if (voice[0] != voice[1])
|
|
|
811 *pitch = s->iptold;
|
|
|
812 }
|
|
|
813 else
|
|
|
814 {
|
|
|
815 /* Do error correction pitch and voicing */
|
|
|
816 if (i4 > 4)
|
|
|
817 {
|
|
|
818 s->dpit[0] = i4;
|
|
|
819 ivoic = 2;
|
|
|
820 s->iavgp = (s->iavgp*15 + i4 + 8)/16;
|
|
|
821 }
|
|
|
822 else
|
|
|
823 {
|
|
|
824 s->dpit[0] = s->iavgp;
|
|
|
825 ivoic = i4;
|
|
|
826 }
|
|
|
827 s->drms[0] = t->irms;
|
|
|
828 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
829 s->drc[i][0] = t->irc[i];
|
|
|
830 /* Determine index to IVTAB from V/UV decision */
|
|
|
831 /* If error rate is high then use alternate table */
|
|
|
832 index = (s->ivp2h << 4) + (s->iovoic << 2) + ivoic + 1;
|
|
|
833 i1 = ivtab[index - 1];
|
|
|
834 ipit = i1 & 3;
|
|
|
835 icorf = i1 >> 3;
|
|
|
836 if (s->erate < 2048)
|
|
|
837 icorf /= 64;
|
|
|
838 /* Determine error rate: 4=high 1=low */
|
|
|
839 ixcor = 4;
|
|
|
840 if (s->erate < 2048)
|
|
|
841 ixcor = 3;
|
|
|
842 if (s->erate < 1024)
|
|
|
843 ixcor = 2;
|
|
|
844 if (s->erate < 128)
|
|
|
845 ixcor = 1;
|
|
|
846 /* Voice/unvoice decision determined from bits 0 and 1 of IVTAB */
|
|
|
847 voice[0] = icorf/2 & 1;
|
|
|
848 voice[1] = icorf & 1;
|
|
|
849 /* Skip decoding on first frame because present data not yet available */
|
|
|
850 if (s->first)
|
|
|
851 {
|
|
|
852 s->first = FALSE;
|
|
|
853 /* Assign PITCH a "default" value on the first call, since */
|
|
|
854 /* otherwise it would be left uninitialized. The two lines */
|
|
|
855 /* below were copied from above, since it seemed like a */
|
|
|
856 /* reasonable thing to do for the first call. */
|
|
|
857 if (i4 <= 4)
|
|
|
858 i4 = s->iptold;
|
|
|
859 *pitch = i4;
|
|
|
860 }
|
|
|
861 else
|
|
|
862 {
|
|
|
863 /* If bit 4 of ICORF is set then correct RMS and RC(1) - RC(4). */
|
|
|
864 /* Determine error rate and correct errors using a Hamming 8,4 code */
|
|
|
865 /* during transition of unvoiced frames. If IOUT is negative, */
|
|
|
866 /* more than 1 error occurred, use previous frame's parameters. */
|
|
|
867 if ((icorf & bit[3]) != 0)
|
|
|
868 {
|
|
|
869 errcnt = 0;
|
|
|
870 lsb = s->drms[1] & 1;
|
|
|
871 index = (s->drc[7][1] << 4) + s->drms[1]/2;
|
|
|
872 iout = hamming_84_decode(index, &errcnt);
|
|
|
873 s->drms[1] = s->drms[2];
|
|
|
874 if (iout >= 0)
|
|
|
875 s->drms[1] = (iout << 1) + lsb;
|
|
|
876 for (i = 1; i <= 4; i++)
|
|
|
877 {
|
|
|
878 if (i == 1)
|
|
|
879 i1 = ((s->drc[8][1] & 7) << 1) + (s->drc[9][1] & 1);
|
|
|
880 else
|
|
|
881 i1 = s->drc[8 - i][1] & 15;
|
|
|
882 i2 = s->drc[4 - i][1] & 31;
|
|
|
883 lsb = i2 & 1;
|
|
|
884 index = (i1 << 4) + (i2 >> 1);
|
|
|
885 iout = hamming_84_decode(index, &errcnt);
|
|
|
886 if (iout >= 0)
|
|
|
887 {
|
|
|
888 iout = (iout << 1) + lsb;
|
|
|
889 if ((iout & 16) == 16)
|
|
|
890 iout -= 32;
|
|
|
891 }
|
|
|
892 else
|
|
|
893 {
|
|
|
894 iout = s->drc[4 - i][2];
|
|
|
895 }
|
|
|
896 s->drc[4 - i][1] = iout;
|
|
|
897 }
|
|
|
898 /* Determine error rate */
|
|
|
899 s->erate = s->erate*0.96875f + errcnt*102.0f;
|
|
|
900 }
|
|
|
901 /* Get unsmoothed RMS, RC's, and PITCH */
|
|
|
902 t->irms = s->drms[1];
|
|
|
903 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
904 t->irc[i] = s->drc[i][1];
|
|
|
905 if (ipit == 1)
|
|
|
906 s->dpit[1] = s->dpit[2];
|
|
|
907 if (ipit == 3)
|
|
|
908 s->dpit[1] = s->dpit[0];
|
|
|
909 *pitch = s->dpit[1];
|
|
|
910 /* If bit 2 of ICORF is set then smooth RMS and RC's, */
|
|
|
911 if ((icorf & bit[1]) != 0)
|
|
|
912 {
|
|
|
913 if ((float) abs(s->drms[1] - s->drms[0]) >= corth[ixcor + 3]
|
|
|
914 &&
|
|
|
915 (float) abs(s->drms[1] - s->drms[2]) >= corth[ixcor + 3])
|
|
|
916 {
|
|
|
917 t->irms = median(s->drms[2], s->drms[1], s->drms[0]);
|
|
|
918 }
|
|
|
919 for (i = 0; i < 6; i++)
|
|
|
920 {
|
|
|
921 if ((float) abs(s->drc[i][1] - s->drc[i][0]) >= corth[ixcor + ((i + 3) << 2) - 5]
|
|
|
922 &&
|
|
|
923 (float) abs(s->drc[i][1] - s->drc[i][2]) >= corth[ixcor + ((i + 3) << 2) - 5])
|
|
|
924 {
|
|
|
925 t->irc[i] = median(s->drc[i][2], s->drc[i][1], s->drc[i][0]);
|
|
|
926 }
|
|
|
927 }
|
|
|
928 }
|
|
|
929 /* If bit 3 of ICORF is set then smooth pitch */
|
|
|
930 if ((icorf & bit[2]) != 0)
|
|
|
931 {
|
|
|
932 if ((float) abs(s->dpit[1] - s->dpit[0]) >= corth[ixcor - 1]
|
|
|
933 &&
|
|
|
934 (float) abs(s->dpit[1] - s->dpit[2]) >= corth[ixcor - 1])
|
|
|
935 {
|
|
|
936 *pitch = median(s->dpit[2], s->dpit[1], s->dpit[0]);
|
|
|
937 }
|
|
|
938 }
|
|
|
939 /* If bit 5 of ICORF is set then RC(5) - RC(10) are loaded with
|
|
|
940 values so that after quantization bias is removed in decode
|
|
|
941 the values will be zero. */
|
|
|
942 }
|
|
|
943 if ((icorf & bit[4]) != 0)
|
|
|
944 {
|
|
|
945 for (i = 4; i < LPC10_ORDER; i++)
|
|
|
946 t->irc[i] = zrc[i];
|
|
|
947 }
|
|
|
948 /* Housekeeping - one frame delay */
|
|
|
949 s->iovoic = ivoic;
|
|
|
950 s->ivp2h = voice[1];
|
|
|
951 s->dpit[2] = s->dpit[1];
|
|
|
952 s->dpit[1] = s->dpit[0];
|
|
|
953 s->drms[2] = s->drms[1];
|
|
|
954 s->drms[1] = s->drms[0];
|
|
|
955 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
956 {
|
|
|
957 s->drc[i][2] = s->drc[i][1];
|
|
|
958 s->drc[i][1] = s->drc[i][0];
|
|
|
959 }
|
|
|
960 }
|
|
|
961 /* Decode RMS */
|
|
|
962 t->irms = rmst[(31 - t->irms)*2];
|
|
|
963 /* Decode RC(1) and RC(2) from log-area-ratios */
|
|
|
964 /* Protect from illegal coded value (-16) caused by bit errors */
|
|
|
965 for (i = 0; i < 2; i++)
|
|
|
966 {
|
|
|
967 i2 = t->irc[i];
|
|
|
968 i1 = 0;
|
|
|
969 if (i2 < 0)
|
|
|
970 {
|
|
|
971 i1 = 1;
|
|
|
972 i2 = -i2;
|
|
|
973 if (i2 > 15)
|
|
|
974 i2 = 0;
|
|
|
975 }
|
|
|
976 i2 = detab7[i2*2];
|
|
|
977 if (i1 == 1)
|
|
|
978 i2 = -i2;
|
|
|
979 ishift = 15 - nbit[i];
|
|
|
980 t->irc[i] = i2*pow_ii(2, ishift);
|
|
|
981 }
|
|
|
982 /* Decode RC(3)-RC(10) to sign plus 14 bits */
|
|
|
983 for (i = 2; i < LPC10_ORDER; i++)
|
|
|
984 {
|
|
|
985 ishift = 15 - nbit[i];
|
|
|
986 i2 = t->irc[i]*pow_ii(2, ishift) + qb[i - 2];
|
|
|
987 t->irc[i] = i2*descl[i - 2] + deadd[i - 2];
|
|
|
988 }
|
|
|
989 /* Scale RMS and RC's to floats */
|
|
|
990 *rms = (float) t->irms;
|
|
|
991 for (i = 0; i < LPC10_ORDER; i++)
|
|
|
992 rc[i] = t->irc[i]/16384.0f;
|
|
|
993 }
|
|
|
994 /*- End of function --------------------------------------------------------*/
|
|
|
995
|
|
|
996 lpc10_decode_state_t *lpc10_decode_init(lpc10_decode_state_t *s, int error_correction)
|
|
|
997 {
|
|
|
998 static const int16_t rand_init[] =
|
|
|
999 {
|
|
|
1000 -21161,
|
|
|
1001 -8478,
|
|
|
1002 30892,
|
|
|
1003 -10216,
|
|
|
1004 16950
|
|
|
1005 };
|
|
|
1006 int i;
|
|
|
1007 int j;
|
|
|
1008
|
|
|
1009 if (s == NULL)
|
|
|
1010 {
|
|
|
1011 if ((s = (lpc10_decode_state_t *) malloc(sizeof(lpc10_decode_state_t))) == NULL)
|
|
|
1012 return NULL;
|
|
|
1013 }
|
|
|
1014
|
|
|
1015 s->error_correction = error_correction;
|
|
|
1016
|
|
|
1017 /* State used by function decode */
|
|
|
1018 s->iptold = 60;
|
|
|
1019 s->first = TRUE;
|
|
|
1020 s->ivp2h = 0;
|
|
|
1021 s->iovoic = 0;
|
|
|
1022 s->iavgp = 60;
|
|
|
1023 s->erate = 0;
|
|
|
1024 for (i = 0; i < 3; i++)
|
|
|
1025 {
|
|
|
1026 for (j = 0; j < 10; j++)
|
|
|
1027 s->drc[j][i] = 0;
|
|
|
1028 s->dpit[i] = 0;
|
|
|
1029 s->drms[i] = 0;
|
|
|
1030 }
|
|
|
1031
|
|
|
1032 /* State used by function synths */
|
|
|
1033 for (i = 0; i < 360; i++)
|
|
|
1034 s->buf[i] = 0.0f;
|
|
|
1035 s->buflen = LPC10_SAMPLES_PER_FRAME;
|
|
|
1036
|
|
|
1037 /* State used by function pitsyn */
|
|
|
1038 s->rmso = 1.0f;
|
|
|
1039 s->first_pitsyn = TRUE;
|
|
|
1040
|
|
|
1041 /* State used by function bsynz */
|
|
|
1042 s->ipo = 0;
|
|
|
1043 for (i = 0; i < 166; i++)
|
|
|
1044 {
|
|
|
1045 s->exc[i] = 0.0f;
|
|
|
1046 s->exc2[i] = 0.0f;
|
|
|
1047 }
|
|
|
1048 for (i = 0; i < 3; i++)
|
|
|
1049 {
|
|
|
1050 s->lpi[i] = 0.0f;
|
|
|
1051 s->hpi[i] = 0.0f;
|
|
|
1052 }
|
|
|
1053 s->rmso_bsynz = 0.0f;
|
|
|
1054
|
|
|
1055 /* State used by function lpc10_random */
|
|
|
1056 s->j = 1;
|
|
|
1057 s->k = 4;
|
|
|
1058 for (i = 0; i < 5; i++)
|
|
|
1059 s->y[i] = rand_init[i];
|
|
|
1060
|
|
|
1061 /* State used by function deemp */
|
|
|
1062 for (i = 0; i < 2; i++)
|
|
|
1063 s->dei[i] = 0.0f;
|
|
|
1064 for (i = 0; i < 3; i++)
|
|
|
1065 s->deo[i] = 0.0f;
|
|
|
1066
|
|
|
1067 return s;
|
|
|
1068 }
|
|
|
1069 /*- End of function --------------------------------------------------------*/
|
|
|
1070
|
|
|
1071 int lpc10_decode_release(lpc10_decode_state_t *s)
|
|
|
1072 {
|
|
|
1073 free(s);
|
|
|
1074 return 0;
|
|
|
1075 }
|
|
|
1076 /*- End of function --------------------------------------------------------*/
|
|
|
1077
|
|
|
1078 int lpc10_decode(lpc10_decode_state_t *s, int16_t amp[], const uint8_t code[], int quant)
|
|
|
1079 {
|
|
|
1080 int voice[2];
|
|
|
1081 int32_t pitch;
|
|
|
1082 float speech[LPC10_SAMPLES_PER_FRAME];
|
|
|
1083 float rc[LPC10_ORDER];
|
|
|
1084 lpc10_frame_t frame;
|
|
|
1085 float rms;
|
|
|
1086 int i;
|
|
|
1087 int j;
|
|
|
1088
|
|
|
1089 /* Decode 54 bits to LPC10_SAMPLES_PER_FRAME speech samples. */
|
|
|
1090 for (i = 0; i < quant; i++)
|
|
|
1091 {
|
|
|
1092 lpc10_unpack(&frame, &code[i*7]);
|
|
|
1093 decode(s, &frame, voice, &pitch, &rms, rc);
|
|
|
1094 synths(s, voice, &pitch, &rms, rc, speech);
|
|
|
1095 for (j = 0; j < LPC10_SAMPLES_PER_FRAME; j++)
|
|
|
1096 amp[i*LPC10_SAMPLES_PER_FRAME + j] = rintf(32768.0f*speech[j]);
|
|
|
1097 }
|
|
|
1098
|
|
|
1099 return quant*LPC10_SAMPLES_PER_FRAME;
|
|
|
1100 }
|
|
|
1101 /*- End of function --------------------------------------------------------*/
|
|
|
1102 /*- End of file ------------------------------------------------------------*/
|
