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1 /*
2  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 /*
12  * entropy_coding.c
13  *
14  * This header file defines all of the functions used to arithmetically
15  * encode the iSAC bistream
16  *
17  */
18 
19 
20 #include "common_audio/signal_processing/include/signal_processing_library.h"
21 #include "modules/audio_coding/codecs/isac/main/source/entropy_coding.h"
22 #include "modules/audio_coding/codecs/isac/main/source/settings.h"
23 #include "modules/audio_coding/codecs/isac/main/source/arith_routines.h"
24 #include "modules/audio_coding/codecs/isac/main/source/spectrum_ar_model_tables.h"
25 #include "modules/audio_coding/codecs/isac/main/source/lpc_tables.h"
26 #include "modules/audio_coding/codecs/isac/main/source/pitch_gain_tables.h"
27 #include "modules/audio_coding/codecs/isac/main/source/pitch_lag_tables.h"
28 #include "modules/audio_coding/codecs/isac/main/source/encode_lpc_swb.h"
29 #include "modules/audio_coding/codecs/isac/main/source/lpc_shape_swb12_tables.h"
30 #include "modules/audio_coding/codecs/isac/main/source/lpc_shape_swb16_tables.h"
31 #include "modules/audio_coding/codecs/isac/main/source/lpc_gain_swb_tables.h"
32 #include "modules/audio_coding/codecs/isac/main/source/os_specific_inline.h"
33 
34 #include <math.h>
35 #include <string.h>
36 
37 static const uint16_t kLpcVecPerSegmentUb12 = 5;
38 static const uint16_t kLpcVecPerSegmentUb16 = 4;
39 
40 /* CDF array for encoder bandwidth (12 vs 16 kHz) indicator. */
41 static const uint16_t kOneBitEqualProbCdf[3] = {
42     0, 32768, 65535 };
43 
44 /* Pointer to cdf array for encoder bandwidth (12 vs 16 kHz) indicator. */
45 static const uint16_t* const kOneBitEqualProbCdf_ptr[1] = {
46     kOneBitEqualProbCdf };
47 
48 /*
49  * Initial cdf index for decoder of encoded bandwidth
50  * (12 vs 16 kHz) indicator.
51  */
52 static const uint16_t kOneBitEqualProbInitIndex[1] = { 1 };
53 
54 
55 static const int kIsSWB12 = 1;
56 
57 /* compute correlation from power spectrum */
FindCorrelation(int32_t * PSpecQ12,int32_t * CorrQ7)58 static void FindCorrelation(int32_t* PSpecQ12, int32_t* CorrQ7) {
59   int32_t summ[FRAMESAMPLES / 8];
60   int32_t diff[FRAMESAMPLES / 8];
61   const int16_t* CS_ptrQ9;
62   int32_t sum;
63   int k, n;
64 
65   for (k = 0; k < FRAMESAMPLES / 8; k++) {
66     summ[k] = (PSpecQ12[k] + PSpecQ12[FRAMESAMPLES_QUARTER - 1 - k] + 16) >> 5;
67     diff[k] = (PSpecQ12[k] - PSpecQ12[FRAMESAMPLES_QUARTER - 1 - k] + 16) >> 5;
68   }
69 
70   sum = 2;
71   for (n = 0; n < FRAMESAMPLES / 8; n++) {
72     sum += summ[n];
73   }
74   CorrQ7[0] = sum;
75 
76   for (k = 0; k < AR_ORDER; k += 2) {
77     sum = 0;
78     CS_ptrQ9 = WebRtcIsac_kCos[k];
79     for (n = 0; n < FRAMESAMPLES / 8; n++)
80       sum += (CS_ptrQ9[n] * diff[n] + 256) >> 9;
81     CorrQ7[k + 1] = sum;
82   }
83 
84   for (k = 1; k < AR_ORDER; k += 2) {
85     sum = 0;
86     CS_ptrQ9 = WebRtcIsac_kCos[k];
87     for (n = 0; n < FRAMESAMPLES / 8; n++)
88       sum += (CS_ptrQ9[n] * summ[n] + 256) >> 9;
89     CorrQ7[k + 1] = sum;
90   }
91 }
92 
93 /* compute inverse AR power spectrum */
94 /* Changed to the function used in iSAC FIX for compatibility reasons */
FindInvArSpec(const int16_t * ARCoefQ12,const int32_t gainQ10,int32_t * CurveQ16)95 static void FindInvArSpec(const int16_t* ARCoefQ12,
96                           const int32_t gainQ10,
97                           int32_t* CurveQ16) {
98   int32_t CorrQ11[AR_ORDER + 1];
99   int64_t sum, tmpGain;
100   int32_t diffQ16[FRAMESAMPLES / 8];
101   const int16_t* CS_ptrQ9;
102   int k, n;
103   int16_t round, shftVal = 0, sh;
104 
105   sum = 0;
106   for (n = 0; n < AR_ORDER + 1; n++) {
107     sum += WEBRTC_SPL_MUL(ARCoefQ12[n], ARCoefQ12[n]);   /* Q24 */
108   }
109   sum = ((sum >> 6) * 65 + 32768) >> 16;  /* Q8 */
110   CorrQ11[0] = (sum * gainQ10 + 256) >> 9;
111 
112   /* To avoid overflow, we shift down gainQ10 if it is large.
113    * We will not lose any precision */
114   if (gainQ10 > 400000) {
115     tmpGain = gainQ10 >> 3;
116     round = 32;
117     shftVal = 6;
118   } else {
119     tmpGain = gainQ10;
120     round = 256;
121     shftVal = 9;
122   }
123 
124   for (k = 1; k < AR_ORDER + 1; k++) {
125     sum = 16384;
126     for (n = k; n < AR_ORDER + 1; n++)
127       sum += WEBRTC_SPL_MUL(ARCoefQ12[n - k], ARCoefQ12[n]); /* Q24 */
128     sum >>= 15;
129     CorrQ11[k] = (sum * tmpGain + round) >> shftVal;
130   }
131   sum = CorrQ11[0] << 7;
132   for (n = 0; n < FRAMESAMPLES / 8; n++) {
133     CurveQ16[n] = sum;
134   }
135   for (k = 1; k < AR_ORDER; k += 2) {
136     for (n = 0; n < FRAMESAMPLES / 8; n++) {
137       CurveQ16[n] += (WebRtcIsac_kCos[k][n] * CorrQ11[k + 1] + 2) >> 2;
138     }
139   }
140 
141   CS_ptrQ9 = WebRtcIsac_kCos[0];
142 
143   /* If CorrQ11[1] too large we avoid getting overflow in the
144    * calculation by shifting */
145   sh = WebRtcSpl_NormW32(CorrQ11[1]);
146   if (CorrQ11[1] == 0) { /* Use next correlation */
147     sh = WebRtcSpl_NormW32(CorrQ11[2]);
148   }
149   if (sh < 9) {
150     shftVal = 9 - sh;
151   } else {
152     shftVal = 0;
153   }
154   for (n = 0; n < FRAMESAMPLES / 8; n++) {
155     diffQ16[n] = (CS_ptrQ9[n] * (CorrQ11[1] >> shftVal) + 2) >> 2;
156   }
157   for (k = 2; k < AR_ORDER; k += 2) {
158     CS_ptrQ9 = WebRtcIsac_kCos[k];
159     for (n = 0; n < FRAMESAMPLES / 8; n++) {
160       diffQ16[n] += (CS_ptrQ9[n] * (CorrQ11[k + 1] >> shftVal) + 2) >> 2;
161     }
162   }
163 
164   for (k = 0; k < FRAMESAMPLES / 8; k++) {
165     int32_t diff_q16_shifted = (int32_t)((uint32_t)(diffQ16[k]) << shftVal);
166     CurveQ16[FRAMESAMPLES_QUARTER - 1 - k] = CurveQ16[k] - diff_q16_shifted;
167     CurveQ16[k] += diff_q16_shifted;
168   }
169 }
170 
171 /* Generate array of dither samples in Q7. */
GenerateDitherQ7Lb(int16_t * bufQ7,uint32_t seed,int length,int16_t AvgPitchGain_Q12)172 static void GenerateDitherQ7Lb(int16_t* bufQ7, uint32_t seed,
173                                int length, int16_t AvgPitchGain_Q12) {
174   int   k, shft;
175   int16_t dither1_Q7, dither2_Q7, dither_gain_Q14;
176 
177   /* This threshold should be equal to that in decode_spec(). */
178   if (AvgPitchGain_Q12 < 614) {
179     for (k = 0; k < length - 2; k += 3) {
180       /* New random unsigned int. */
181       seed = (seed * 196314165) + 907633515;
182 
183       /* Fixed-point dither sample between -64 and 64 (Q7). */
184       /* dither = seed * 128 / 4294967295 */
185       dither1_Q7 = (int16_t)(((int32_t)(seed + 16777216)) >> 25);
186 
187       /* New random unsigned int. */
188       seed = (seed * 196314165) + 907633515;
189 
190       /* Fixed-point dither sample between -64 and 64. */
191       dither2_Q7 = (int16_t)(((int32_t)(seed + 16777216)) >> 25);
192 
193       shft = (seed >> 25) & 15;
194       if (shft < 5) {
195         bufQ7[k]   = dither1_Q7;
196         bufQ7[k + 1] = dither2_Q7;
197         bufQ7[k + 2] = 0;
198       } else if (shft < 10) {
199         bufQ7[k]   = dither1_Q7;
200         bufQ7[k + 1] = 0;
201         bufQ7[k + 2] = dither2_Q7;
202       } else {
203         bufQ7[k]   = 0;
204         bufQ7[k + 1] = dither1_Q7;
205         bufQ7[k + 2] = dither2_Q7;
206       }
207     }
208   } else {
209     dither_gain_Q14 = (int16_t)(22528 - 10 * AvgPitchGain_Q12);
210 
211     /* Dither on half of the coefficients. */
212     for (k = 0; k < length - 1; k += 2) {
213       /* New random unsigned int */
214       seed = (seed * 196314165) + 907633515;
215 
216       /* Fixed-point dither sample between -64 and 64. */
217       dither1_Q7 = (int16_t)(((int32_t)(seed + 16777216)) >> 25);
218 
219       /* Dither sample is placed in either even or odd index. */
220       shft = (seed >> 25) & 1;     /* Either 0 or 1 */
221 
222       bufQ7[k + shft] = (((dither_gain_Q14 * dither1_Q7) + 8192) >> 14);
223       bufQ7[k + 1 - shft] = 0;
224     }
225   }
226 }
227 
228 
229 
230 /******************************************************************************
231  * GenerateDitherQ7LbUB()
232  *
233  * generate array of dither samples in Q7 There are less zeros in dither
234  * vector compared to GenerateDitherQ7Lb.
235  *
236  * A uniform random number generator with the range of [-64 64] is employed
237  * but the generated dithers are scaled by 0.35, a heuristic scaling.
238  *
239  * Input:
240  *      -seed               : the initial seed for the random number generator.
241  *      -length             : the number of dither values to be generated.
242  *
243  * Output:
244  *      -bufQ7              : pointer to a buffer where dithers are written to.
245  */
GenerateDitherQ7LbUB(int16_t * bufQ7,uint32_t seed,int length)246 static void GenerateDitherQ7LbUB(
247     int16_t* bufQ7,
248     uint32_t seed,
249     int length) {
250   int k;
251   for (k = 0; k < length; k++) {
252     /* new random unsigned int */
253     seed = (seed * 196314165) + 907633515;
254 
255     /* Fixed-point dither sample between -64 and 64 (Q7). */
256     /* bufQ7 = seed * 128 / 4294967295 */
257     bufQ7[k] = (int16_t)(((int32_t)(seed + 16777216)) >> 25);
258 
259     /* Scale by 0.35. */
260     bufQ7[k] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(bufQ7[k], 2048, 13);
261   }
262 }
263 
264 /*
265  * Function to decode the complex spectrum from the bit stream
266  * returns the total number of bytes in the stream.
267  */
WebRtcIsac_DecodeSpec(Bitstr * streamdata,int16_t AvgPitchGain_Q12,enum ISACBand band,double * fr,double * fi)268 int WebRtcIsac_DecodeSpec(Bitstr* streamdata, int16_t AvgPitchGain_Q12,
269                           enum ISACBand band, double* fr, double* fi) {
270   int16_t  DitherQ7[FRAMESAMPLES];
271   int16_t  data[FRAMESAMPLES];
272   int32_t  invARSpec2_Q16[FRAMESAMPLES_QUARTER];
273   uint16_t invARSpecQ8[FRAMESAMPLES_QUARTER];
274   int16_t  ARCoefQ12[AR_ORDER + 1];
275   int16_t  RCQ15[AR_ORDER];
276   int16_t  gainQ10;
277   int32_t  gain2_Q10, res;
278   int32_t  in_sqrt;
279   int32_t  newRes;
280   int k, len, i;
281   int is_12khz = !kIsSWB12;
282   int num_dft_coeff = FRAMESAMPLES;
283   /* Create dither signal. */
284   if (band == kIsacLowerBand) {
285     GenerateDitherQ7Lb(DitherQ7, streamdata->W_upper, FRAMESAMPLES,
286                        AvgPitchGain_Q12);
287   } else {
288     GenerateDitherQ7LbUB(DitherQ7, streamdata->W_upper, FRAMESAMPLES);
289     if (band == kIsacUpperBand12) {
290       is_12khz = kIsSWB12;
291       num_dft_coeff = FRAMESAMPLES_HALF;
292     }
293   }
294 
295   /* Decode model parameters. */
296   if (WebRtcIsac_DecodeRc(streamdata, RCQ15) < 0)
297     return -ISAC_RANGE_ERROR_DECODE_SPECTRUM;
298 
299   WebRtcSpl_ReflCoefToLpc(RCQ15, AR_ORDER, ARCoefQ12);
300 
301   if (WebRtcIsac_DecodeGain2(streamdata, &gain2_Q10) < 0)
302     return -ISAC_RANGE_ERROR_DECODE_SPECTRUM;
303 
304   /* Compute inverse AR power spectrum. */
305   FindInvArSpec(ARCoefQ12, gain2_Q10, invARSpec2_Q16);
306 
307   /* Convert to magnitude spectrum,
308    * by doing square-roots (modified from SPLIB). */
309   res = 1 << (WebRtcSpl_GetSizeInBits(invARSpec2_Q16[0]) >> 1);
310   for (k = 0; k < FRAMESAMPLES_QUARTER; k++) {
311     in_sqrt = invARSpec2_Q16[k];
312     i = 10;
313 
314     /* Negative values make no sense for a real sqrt-function. */
315     if (in_sqrt < 0)
316       in_sqrt = -in_sqrt;
317 
318     newRes = (in_sqrt / res + res) >> 1;
319     do {
320       res = newRes;
321       newRes = (in_sqrt / res + res) >> 1;
322     } while (newRes != res && i-- > 0);
323 
324     invARSpecQ8[k] = (int16_t)newRes;
325   }
326 
327   len = WebRtcIsac_DecLogisticMulti2(data, streamdata, invARSpecQ8, DitherQ7,
328                                      num_dft_coeff, is_12khz);
329   /* Arithmetic decoding of spectrum. */
330   if (len < 1) {
331     return -ISAC_RANGE_ERROR_DECODE_SPECTRUM;
332   }
333 
334   switch (band) {
335     case kIsacLowerBand: {
336       /* Scale down spectral samples with low SNR. */
337       int32_t p1;
338       int32_t p2;
339       if (AvgPitchGain_Q12 <= 614) {
340         p1 = 30 << 10;
341         p2 = 32768 + (33 << 16);
342       } else {
343         p1 = 36 << 10;
344         p2 = 32768 + (40 << 16);
345       }
346       for (k = 0; k < FRAMESAMPLES; k += 4) {
347         gainQ10 = WebRtcSpl_DivW32W16ResW16(p1, (int16_t)(
348             (invARSpec2_Q16[k >> 2] + p2) >> 16));
349         *fr++ = (double)((data[ k ] * gainQ10 + 512) >> 10) / 128.0;
350         *fi++ = (double)((data[k + 1] * gainQ10 + 512) >> 10) / 128.0;
351         *fr++ = (double)((data[k + 2] * gainQ10 + 512) >> 10) / 128.0;
352         *fi++ = (double)((data[k + 3] * gainQ10 + 512) >> 10) / 128.0;
353       }
354       break;
355     }
356     case kIsacUpperBand12: {
357       for (k = 0, i = 0; k < FRAMESAMPLES_HALF; k += 4) {
358         fr[i] = (double)data[ k ] / 128.0;
359         fi[i] = (double)data[k + 1] / 128.0;
360         i++;
361         fr[i] = (double)data[k + 2] / 128.0;
362         fi[i] = (double)data[k + 3] / 128.0;
363         i++;
364       }
365       /* The second half of real and imaginary coefficients is zero. This is
366        * due to using the old FFT module which requires two signals as input
367        * while in 0-12 kHz mode we only have 8-12 kHz band, and the second
368        * signal is set to zero. */
369       memset(&fr[FRAMESAMPLES_QUARTER], 0, FRAMESAMPLES_QUARTER *
370              sizeof(double));
371       memset(&fi[FRAMESAMPLES_QUARTER], 0, FRAMESAMPLES_QUARTER *
372              sizeof(double));
373       break;
374     }
375     case kIsacUpperBand16: {
376       for (i = 0, k = 0; k < FRAMESAMPLES; k += 4, i++) {
377         fr[i] = (double)data[ k ] / 128.0;
378         fi[i] = (double)data[k + 1] / 128.0;
379         fr[(FRAMESAMPLES_HALF) - 1 - i] = (double)data[k + 2] / 128.0;
380         fi[(FRAMESAMPLES_HALF) - 1 - i] = (double)data[k + 3] / 128.0;
381       }
382       break;
383     }
384   }
385   return len;
386 }
387 
388 
WebRtcIsac_EncodeSpec(const int16_t * fr,const int16_t * fi,int16_t AvgPitchGain_Q12,enum ISACBand band,Bitstr * streamdata)389 int WebRtcIsac_EncodeSpec(const int16_t* fr, const int16_t* fi,
390                           int16_t AvgPitchGain_Q12, enum ISACBand band,
391                           Bitstr* streamdata) {
392   int16_t ditherQ7[FRAMESAMPLES];
393   int16_t dataQ7[FRAMESAMPLES];
394   int32_t PSpec[FRAMESAMPLES_QUARTER];
395   int32_t invARSpec2_Q16[FRAMESAMPLES_QUARTER];
396   uint16_t invARSpecQ8[FRAMESAMPLES_QUARTER];
397   int32_t CorrQ7[AR_ORDER + 1];
398   int32_t CorrQ7_norm[AR_ORDER + 1];
399   int16_t RCQ15[AR_ORDER];
400   int16_t ARCoefQ12[AR_ORDER + 1];
401   int32_t gain2_Q10;
402   int16_t val;
403   int32_t nrg, res;
404   uint32_t sum;
405   int32_t in_sqrt;
406   int32_t newRes;
407   int16_t err;
408   uint32_t nrg_u32;
409   int shift_var;
410   int k, n, j, i;
411   int is_12khz = !kIsSWB12;
412   int num_dft_coeff = FRAMESAMPLES;
413 
414   /* Create dither signal. */
415   if (band == kIsacLowerBand) {
416     GenerateDitherQ7Lb(ditherQ7, streamdata->W_upper, FRAMESAMPLES,
417                        AvgPitchGain_Q12);
418   } else {
419     GenerateDitherQ7LbUB(ditherQ7, streamdata->W_upper, FRAMESAMPLES);
420     if (band == kIsacUpperBand12) {
421       is_12khz = kIsSWB12;
422       num_dft_coeff = FRAMESAMPLES_HALF;
423     }
424   }
425 
426   /* add dither and quantize, and compute power spectrum */
427   switch (band) {
428     case kIsacLowerBand: {
429       for (k = 0; k < FRAMESAMPLES; k += 4) {
430         val = ((*fr++ + ditherQ7[k]   + 64) & 0xFF80) - ditherQ7[k];
431         dataQ7[k] = val;
432         sum = val * val;
433 
434         val = ((*fi++ + ditherQ7[k + 1] + 64) & 0xFF80) - ditherQ7[k + 1];
435         dataQ7[k + 1] = val;
436         sum += val * val;
437 
438         val = ((*fr++ + ditherQ7[k + 2] + 64) & 0xFF80) - ditherQ7[k + 2];
439         dataQ7[k + 2] = val;
440         sum += val * val;
441 
442         val = ((*fi++ + ditherQ7[k + 3] + 64) & 0xFF80) - ditherQ7[k + 3];
443         dataQ7[k + 3] = val;
444         sum += val * val;
445 
446         PSpec[k >> 2] = sum >> 2;
447       }
448       break;
449     }
450     case kIsacUpperBand12: {
451       for (k = 0, j = 0; k < FRAMESAMPLES_HALF; k += 4) {
452         val = ((*fr++ + ditherQ7[k]   + 64) & 0xFF80) - ditherQ7[k];
453         dataQ7[k] = val;
454         sum = val * val;
455 
456         val = ((*fi++ + ditherQ7[k + 1] + 64) & 0xFF80) - ditherQ7[k + 1];
457         dataQ7[k + 1] = val;
458         sum += val * val;
459 
460         PSpec[j++] = sum >> 1;
461 
462         val = ((*fr++ + ditherQ7[k + 2] + 64) & 0xFF80) - ditherQ7[k + 2];
463         dataQ7[k + 2] = val;
464         sum = val * val;
465 
466         val = ((*fi++ + ditherQ7[k + 3] + 64) & 0xFF80) - ditherQ7[k + 3];
467         dataQ7[k + 3] = val;
468         sum += val * val;
469 
470         PSpec[j++] = sum >> 1;
471       }
472       break;
473     }
474     case kIsacUpperBand16: {
475       for (j = 0, k = 0; k < FRAMESAMPLES; k += 4, j++) {
476         val = ((fr[j] + ditherQ7[k]   + 64) & 0xFF80) - ditherQ7[k];
477         dataQ7[k] = val;
478         sum = val * val;
479 
480         val = ((fi[j] + ditherQ7[k + 1] + 64) & 0xFF80) - ditherQ7[k + 1];
481         dataQ7[k + 1] = val;
482         sum += val * val;
483 
484         val = ((fr[(FRAMESAMPLES_HALF) - 1 - j] + ditherQ7[k + 2] + 64) &
485             0xFF80) - ditherQ7[k + 2];
486         dataQ7[k + 2] = val;
487         sum += val * val;
488 
489         val = ((fi[(FRAMESAMPLES_HALF) - 1 - j] + ditherQ7[k + 3] + 64) &
490             0xFF80) - ditherQ7[k + 3];
491         dataQ7[k + 3] = val;
492         sum += val * val;
493 
494         PSpec[k >> 2] = sum >> 2;
495       }
496       break;
497     }
498   }
499 
500   /* compute correlation from power spectrum */
501   FindCorrelation(PSpec, CorrQ7);
502 
503   /* Find AR coefficients */
504   /* Aumber of bit shifts to 14-bit normalize CorrQ7[0]
505    * (leaving room for sign) */
506   shift_var = WebRtcSpl_NormW32(CorrQ7[0]) - 18;
507 
508   if (shift_var > 0) {
509     for (k = 0; k < AR_ORDER + 1; k++) {
510       CorrQ7_norm[k] = CorrQ7[k] << shift_var;
511     }
512   } else {
513     for (k = 0; k < AR_ORDER + 1; k++) {
514       CorrQ7_norm[k] = CorrQ7[k] >> (-shift_var);
515     }
516   }
517 
518   /* Find RC coefficients. */
519   WebRtcSpl_AutoCorrToReflCoef(CorrQ7_norm, AR_ORDER, RCQ15);
520 
521   /* Quantize & code RC Coefficient. */
522   WebRtcIsac_EncodeRc(RCQ15, streamdata);
523 
524   /* RC -> AR coefficients */
525   WebRtcSpl_ReflCoefToLpc(RCQ15, AR_ORDER, ARCoefQ12);
526 
527   /* Compute ARCoef' * Corr * ARCoef in Q19. */
528   nrg = 0;
529   for (j = 0; j <= AR_ORDER; j++) {
530     for (n = 0; n <= j; n++) {
531       nrg += (ARCoefQ12[j] * ((CorrQ7_norm[j - n] * ARCoefQ12[n] + 256) >> 9) +
532           4) >> 3;
533     }
534     for (n = j + 1; n <= AR_ORDER; n++) {
535       nrg += (ARCoefQ12[j] * ((CorrQ7_norm[n - j] * ARCoefQ12[n] + 256) >> 9) +
536           4) >> 3;
537     }
538   }
539 
540   nrg_u32 = (uint32_t)nrg;
541   if (shift_var > 0) {
542     nrg_u32 = nrg_u32 >> shift_var;
543   } else {
544     nrg_u32 = nrg_u32 << (-shift_var);
545   }
546   if (nrg_u32 > 0x7FFFFFFF) {
547     nrg = 0x7FFFFFFF;
548   }  else {
549     nrg = (int32_t)nrg_u32;
550   }
551   /* Also shifts 31 bits to the left! */
552   gain2_Q10 = WebRtcSpl_DivResultInQ31(FRAMESAMPLES_QUARTER, nrg);
553 
554   /* Quantize & code gain2_Q10. */
555   if (WebRtcIsac_EncodeGain2(&gain2_Q10, streamdata)) {
556     return -1;
557   }
558 
559   /* Compute inverse AR power spectrum. */
560   FindInvArSpec(ARCoefQ12, gain2_Q10, invARSpec2_Q16);
561   /* Convert to magnitude spectrum, by doing square-roots
562    * (modified from SPLIB). */
563   res = 1 << (WebRtcSpl_GetSizeInBits(invARSpec2_Q16[0]) >> 1);
564   for (k = 0; k < FRAMESAMPLES_QUARTER; k++) {
565     in_sqrt = invARSpec2_Q16[k];
566     i = 10;
567     /* Negative values make no sense for a real sqrt-function. */
568     if (in_sqrt < 0) {
569       in_sqrt = -in_sqrt;
570     }
571     newRes = (in_sqrt / res + res) >> 1;
572     do {
573       res = newRes;
574       newRes = (in_sqrt / res + res) >> 1;
575     } while (newRes != res && i-- > 0);
576 
577     invARSpecQ8[k] = (int16_t)newRes;
578   }
579   /* arithmetic coding of spectrum */
580   err = WebRtcIsac_EncLogisticMulti2(streamdata, dataQ7, invARSpecQ8,
581                                      num_dft_coeff, is_12khz);
582   if (err < 0) {
583     return (err);
584   }
585   return 0;
586 }
587 
588 
589 /* step-up */
WebRtcIsac_Rc2Poly(double * RC,int N,double * a)590 void WebRtcIsac_Rc2Poly(double* RC, int N, double* a) {
591   int m, k;
592   double tmp[MAX_AR_MODEL_ORDER];
593 
594   a[0] = 1.0;
595   tmp[0] = 1.0;
596   for (m = 1; m <= N; m++) {
597     /* copy */
598     memcpy(&tmp[1], &a[1], (m - 1) * sizeof(double));
599     a[m] = RC[m - 1];
600     for (k = 1; k < m; k++) {
601       a[k] += RC[m - 1] * tmp[m - k];
602     }
603   }
604   return;
605 }
606 
607 /* step-down */
WebRtcIsac_Poly2Rc(double * a,int N,double * RC)608 void WebRtcIsac_Poly2Rc(double* a, int N, double* RC) {
609   int m, k;
610   double tmp[MAX_AR_MODEL_ORDER];
611   double tmp_inv;
612 
613   RC[N - 1] = a[N];
614   for (m = N - 1; m > 0; m--) {
615     tmp_inv = 1.0 / (1.0 - RC[m] * RC[m]);
616     for (k = 1; k <= m; k++) {
617       tmp[k] = (a[k] - RC[m] * a[m - k + 1]) * tmp_inv;
618     }
619 
620     memcpy(&a[1], &tmp[1], (m - 1) * sizeof(double));
621     RC[m - 1] = tmp[m];
622   }
623   return;
624 }
625 
626 
627 #define MAX_ORDER 100
628 
629 /* Matlab's LAR definition */
WebRtcIsac_Rc2Lar(const double * refc,double * lar,int order)630 void WebRtcIsac_Rc2Lar(const double* refc, double* lar, int order) {
631   int k;
632   for (k = 0; k < order; k++) {
633     lar[k] = log((1 + refc[k]) / (1 - refc[k]));
634   }
635 }
636 
637 
WebRtcIsac_Lar2Rc(const double * lar,double * refc,int order)638 void WebRtcIsac_Lar2Rc(const double* lar, double* refc,  int order) {
639   int k;
640   double tmp;
641 
642   for (k = 0; k < order; k++) {
643     tmp = exp(lar[k]);
644     refc[k] = (tmp - 1) / (tmp + 1);
645   }
646 }
647 
WebRtcIsac_Poly2Lar(double * lowband,int orderLo,double * hiband,int orderHi,int Nsub,double * lars)648 void WebRtcIsac_Poly2Lar(double* lowband, int orderLo, double* hiband,
649                          int orderHi, int Nsub, double* lars) {
650   int k;
651   double rc[MAX_ORDER], *inpl, *inph, *outp;
652 
653   inpl = lowband;
654   inph = hiband;
655   outp = lars;
656   for (k = 0; k < Nsub; k++) {
657     /* gains */
658     outp[0] = inpl[0];
659     outp[1] = inph[0];
660     outp += 2;
661 
662     /* Low band */
663     inpl[0] = 1.0;
664     WebRtcIsac_Poly2Rc(inpl, orderLo, rc);
665     WebRtcIsac_Rc2Lar(rc, outp, orderLo);
666     outp += orderLo;
667 
668     /* High band */
669     inph[0] = 1.0;
670     WebRtcIsac_Poly2Rc(inph, orderHi, rc);
671     WebRtcIsac_Rc2Lar(rc, outp, orderHi);
672     outp += orderHi;
673 
674     inpl += orderLo + 1;
675     inph += orderHi + 1;
676   }
677 }
678 
679 
WebRtcIsac_Poly2LarUB(double * lpcVecs,int16_t bandwidth)680 int16_t WebRtcIsac_Poly2LarUB(double* lpcVecs, int16_t bandwidth) {
681   double      poly[MAX_ORDER];
682   double      rc[MAX_ORDER];
683   double*     ptrIO;
684   int16_t vecCntr;
685   int16_t vecSize;
686   int16_t numVec;
687 
688   vecSize = UB_LPC_ORDER;
689   switch (bandwidth) {
690     case isac12kHz: {
691       numVec  = UB_LPC_VEC_PER_FRAME;
692       break;
693     }
694     case isac16kHz: {
695       numVec  = UB16_LPC_VEC_PER_FRAME;
696       break;
697     }
698     default:
699       return -1;
700   }
701 
702   ptrIO = lpcVecs;
703   poly[0] = 1.0;
704   for (vecCntr = 0; vecCntr < numVec; vecCntr++) {
705     memcpy(&poly[1], ptrIO, sizeof(double) * vecSize);
706     WebRtcIsac_Poly2Rc(poly, vecSize, rc);
707     WebRtcIsac_Rc2Lar(rc, ptrIO, vecSize);
708     ptrIO += vecSize;
709   }
710   return 0;
711 }
712 
713 
WebRtcIsac_Lar2Poly(double * lars,double * lowband,int orderLo,double * hiband,int orderHi,int Nsub)714 void WebRtcIsac_Lar2Poly(double* lars, double* lowband, int orderLo,
715                          double* hiband, int orderHi, int Nsub) {
716   int k, orderTot;
717   double rc[MAX_ORDER], *outpl, *outph, *inp;
718 
719   orderTot = (orderLo + orderHi + 2);
720   outpl = lowband;
721   outph = hiband;
722   /* First two elements of 'inp' store gains*/
723   inp = lars;
724   for (k = 0; k < Nsub; k++) {
725     /* Low band */
726     WebRtcIsac_Lar2Rc(&inp[2], rc, orderLo);
727     WebRtcIsac_Rc2Poly(rc, orderLo, outpl);
728 
729     /* High band */
730     WebRtcIsac_Lar2Rc(&inp[orderLo + 2], rc, orderHi);
731     WebRtcIsac_Rc2Poly(rc, orderHi, outph);
732 
733     /* gains */
734     outpl[0] = inp[0];
735     outph[0] = inp[1];
736 
737     outpl += orderLo + 1;
738     outph += orderHi + 1;
739     inp += orderTot;
740   }
741 }
742 
743 /*
744  *  assumes 2 LAR vectors interpolates to 'numPolyVec' A-polynomials
745  *  Note: 'numPolyVecs' includes the first and the last point of the interval
746  */
WebRtcIsac_Lar2PolyInterpolUB(double * larVecs,double * percepFilterParams,int numPolyVecs)747 void WebRtcIsac_Lar2PolyInterpolUB(double* larVecs, double* percepFilterParams,
748                                    int numPolyVecs) {
749   int polyCntr, coeffCntr;
750   double larInterpol[UB_LPC_ORDER];
751   double rc[UB_LPC_ORDER];
752   double delta[UB_LPC_ORDER];
753 
754   /* calculate the step-size for linear interpolation coefficients */
755   for (coeffCntr = 0; coeffCntr < UB_LPC_ORDER; coeffCntr++) {
756     delta[coeffCntr] = (larVecs[UB_LPC_ORDER + coeffCntr] -
757         larVecs[coeffCntr]) / (numPolyVecs - 1);
758   }
759 
760   for (polyCntr = 0; polyCntr < numPolyVecs; polyCntr++) {
761     for (coeffCntr = 0; coeffCntr < UB_LPC_ORDER; coeffCntr++) {
762       larInterpol[coeffCntr] = larVecs[coeffCntr] +
763           delta[coeffCntr] * polyCntr;
764     }
765     WebRtcIsac_Lar2Rc(larInterpol, rc, UB_LPC_ORDER);
766 
767     /* convert to A-polynomial, the following function returns A[0] = 1;
768      * which is written where gains had to be written. Then we write the
769      * gain (outside this function). This way we say a memcpy. */
770     WebRtcIsac_Rc2Poly(rc, UB_LPC_ORDER, percepFilterParams);
771     percepFilterParams += (UB_LPC_ORDER + 1);
772   }
773 }
774 
WebRtcIsac_DecodeLpc(Bitstr * streamdata,double * LPCCoef_lo,double * LPCCoef_hi)775 int WebRtcIsac_DecodeLpc(Bitstr* streamdata, double* LPCCoef_lo,
776                          double* LPCCoef_hi) {
777   double lars[KLT_ORDER_GAIN + KLT_ORDER_SHAPE];
778   int err;
779 
780   err = WebRtcIsac_DecodeLpcCoef(streamdata, lars);
781   if (err < 0) {
782     return -ISAC_RANGE_ERROR_DECODE_LPC;
783   }
784   WebRtcIsac_Lar2Poly(lars, LPCCoef_lo, ORDERLO, LPCCoef_hi, ORDERHI,
785                       SUBFRAMES);
786   return 0;
787 }
788 
WebRtcIsac_DecodeInterpolLpcUb(Bitstr * streamdata,double * percepFilterParams,int16_t bandwidth)789 int16_t WebRtcIsac_DecodeInterpolLpcUb(Bitstr* streamdata,
790                                        double* percepFilterParams,
791                                        int16_t bandwidth) {
792   double lpcCoeff[UB_LPC_ORDER * UB16_LPC_VEC_PER_FRAME];
793   int err;
794   int interpolCntr;
795   int subframeCntr;
796   int16_t numSegments;
797   int16_t numVecPerSegment;
798   int16_t numGains;
799 
800   double percepFilterGains[SUBFRAMES << 1];
801   double* ptrOutParam = percepFilterParams;
802 
803   err = WebRtcIsac_DecodeLpcCoefUB(streamdata, lpcCoeff, percepFilterGains,
804                                    bandwidth);
805   if (err < 0) {
806     return -ISAC_RANGE_ERROR_DECODE_LPC;
807   }
808 
809   switch (bandwidth) {
810     case isac12kHz: {
811       numGains = SUBFRAMES;
812       numSegments = UB_LPC_VEC_PER_FRAME - 1;
813       numVecPerSegment = kLpcVecPerSegmentUb12;
814       break;
815     }
816     case isac16kHz: {
817       numGains = SUBFRAMES << 1;
818       numSegments = UB16_LPC_VEC_PER_FRAME - 1;
819       numVecPerSegment = kLpcVecPerSegmentUb16;
820       break;
821     }
822     default:
823       return -1;
824   }
825 
826   for (interpolCntr = 0; interpolCntr < numSegments; interpolCntr++) {
827     WebRtcIsac_Lar2PolyInterpolUB(&lpcCoeff[interpolCntr * UB_LPC_ORDER],
828                                   ptrOutParam, numVecPerSegment + 1);
829     ptrOutParam += (numVecPerSegment * (UB_LPC_ORDER + 1));
830   }
831 
832   ptrOutParam = percepFilterParams;
833 
834   if (bandwidth == isac16kHz) {
835     ptrOutParam += (1 + UB_LPC_ORDER);
836   }
837 
838   for (subframeCntr = 0; subframeCntr < numGains; subframeCntr++) {
839     *ptrOutParam = percepFilterGains[subframeCntr];
840     ptrOutParam += (1 + UB_LPC_ORDER);
841   }
842   return 0;
843 }
844 
845 
846 /* decode & dequantize LPC Coef */
WebRtcIsac_DecodeLpcCoef(Bitstr * streamdata,double * LPCCoef)847 int WebRtcIsac_DecodeLpcCoef(Bitstr* streamdata, double* LPCCoef) {
848   int j, k, n, pos, pos2, posg, poss, offsg, offss, offs2;
849   int index_g[KLT_ORDER_GAIN], index_s[KLT_ORDER_SHAPE];
850   double tmpcoeffs_g[KLT_ORDER_GAIN], tmpcoeffs_s[KLT_ORDER_SHAPE];
851   double tmpcoeffs2_g[KLT_ORDER_GAIN], tmpcoeffs2_s[KLT_ORDER_SHAPE];
852   double sum;
853   int err;
854   int model = 1;
855 
856   /* entropy decoding of model number */
857   /* We are keeping this for backward compatibility of bit-streams. */
858   err = WebRtcIsac_DecHistOneStepMulti(&model, streamdata,
859                                        WebRtcIsac_kQKltModelCdfPtr,
860                                        WebRtcIsac_kQKltModelInitIndex, 1);
861   if (err < 0) {
862     return err;
863   }
864   /* Only accepted value of model is 0. It is kept in bit-stream for backward
865    * compatibility. */
866   if (model != 0) {
867     return -ISAC_DISALLOWED_LPC_MODEL;
868   }
869 
870   /* entropy decoding of quantization indices */
871   err = WebRtcIsac_DecHistOneStepMulti(
872       index_s, streamdata, WebRtcIsac_kQKltCdfPtrShape,
873       WebRtcIsac_kQKltInitIndexShape, KLT_ORDER_SHAPE);
874   if (err < 0) {
875     return err;
876   }
877   err = WebRtcIsac_DecHistOneStepMulti(
878       index_g, streamdata, WebRtcIsac_kQKltCdfPtrGain,
879       WebRtcIsac_kQKltInitIndexGain, KLT_ORDER_GAIN);
880   if (err < 0) {
881     return err;
882   }
883 
884   /* find quantization levels for coefficients */
885   for (k = 0; k < KLT_ORDER_SHAPE; k++) {
886     tmpcoeffs_s[k] =
887         WebRtcIsac_kQKltLevelsShape[WebRtcIsac_kQKltOffsetShape[k] +
888                                     index_s[k]];
889   }
890   for (k = 0; k < KLT_ORDER_GAIN; k++) {
891     tmpcoeffs_g[k] = WebRtcIsac_kQKltLevelsGain[WebRtcIsac_kQKltOffsetGain[k] +
892                                                 index_g[k]];
893   }
894 
895   /* Inverse KLT  */
896 
897   /* Left transform, transpose matrix!  */
898   offsg = 0;
899   offss = 0;
900   posg = 0;
901   poss = 0;
902   for (j = 0; j < SUBFRAMES; j++) {
903     offs2 = 0;
904     for (k = 0; k < LPC_GAIN_ORDER; k++) {
905       sum = 0;
906       pos = offsg;
907       pos2 = offs2;
908       for (n = 0; n < LPC_GAIN_ORDER; n++) {
909         sum += tmpcoeffs_g[pos++] * WebRtcIsac_kKltT1Gain[pos2++];
910       }
911       tmpcoeffs2_g[posg++] = sum;
912       offs2 += LPC_GAIN_ORDER;
913     }
914     offs2 = 0;
915     for (k = 0; k < LPC_SHAPE_ORDER; k++) {
916       sum = 0;
917       pos = offss;
918       pos2 = offs2;
919       for (n = 0; n < LPC_SHAPE_ORDER; n++) {
920         sum += tmpcoeffs_s[pos++] * WebRtcIsac_kKltT1Shape[pos2++];
921       }
922       tmpcoeffs2_s[poss++] = sum;
923       offs2 += LPC_SHAPE_ORDER;
924     }
925     offsg += LPC_GAIN_ORDER;
926     offss += LPC_SHAPE_ORDER;
927   }
928 
929   /* Right transform, transpose matrix */
930   offsg = 0;
931   offss = 0;
932   posg = 0;
933   poss = 0;
934   for (j = 0; j < SUBFRAMES; j++) {
935     posg = offsg;
936     for (k = 0; k < LPC_GAIN_ORDER; k++) {
937       sum = 0;
938       pos = k;
939       pos2 = j;
940       for (n = 0; n < SUBFRAMES; n++) {
941         sum += tmpcoeffs2_g[pos] * WebRtcIsac_kKltT2Gain[pos2];
942         pos += LPC_GAIN_ORDER;
943         pos2 += SUBFRAMES;
944 
945       }
946       tmpcoeffs_g[posg++] = sum;
947     }
948     poss = offss;
949     for (k = 0; k < LPC_SHAPE_ORDER; k++) {
950       sum = 0;
951       pos = k;
952       pos2 = j;
953       for (n = 0; n < SUBFRAMES; n++) {
954         sum += tmpcoeffs2_s[pos] * WebRtcIsac_kKltT2Shape[pos2];
955         pos += LPC_SHAPE_ORDER;
956         pos2 += SUBFRAMES;
957       }
958       tmpcoeffs_s[poss++] = sum;
959     }
960     offsg += LPC_GAIN_ORDER;
961     offss += LPC_SHAPE_ORDER;
962   }
963 
964   /* scaling, mean addition, and gain restoration */
965   posg = 0;
966   poss = 0;
967   pos = 0;
968   for (k = 0; k < SUBFRAMES; k++) {
969     /* log gains */
970     LPCCoef[pos] = tmpcoeffs_g[posg] / LPC_GAIN_SCALE;
971     LPCCoef[pos] += WebRtcIsac_kLpcMeansGain[posg];
972     LPCCoef[pos] = exp(LPCCoef[pos]);
973     pos++;
974     posg++;
975     LPCCoef[pos] = tmpcoeffs_g[posg] / LPC_GAIN_SCALE;
976     LPCCoef[pos] += WebRtcIsac_kLpcMeansGain[posg];
977     LPCCoef[pos] = exp(LPCCoef[pos]);
978     pos++;
979     posg++;
980 
981     /* Low-band LAR coefficients. */
982     for (n = 0; n < LPC_LOBAND_ORDER; n++, pos++, poss++) {
983       LPCCoef[pos] = tmpcoeffs_s[poss] / LPC_LOBAND_SCALE;
984       LPCCoef[pos] += WebRtcIsac_kLpcMeansShape[poss];
985     }
986 
987     /* High-band LAR coefficients. */
988     for (n = 0; n < LPC_HIBAND_ORDER; n++, pos++, poss++) {
989       LPCCoef[pos] = tmpcoeffs_s[poss] / LPC_HIBAND_SCALE;
990       LPCCoef[pos] += WebRtcIsac_kLpcMeansShape[poss];
991     }
992   }
993   return 0;
994 }
995 
996 /* Encode LPC in LAR domain. */
WebRtcIsac_EncodeLar(double * LPCCoef,Bitstr * streamdata,IsacSaveEncoderData * encData)997 void WebRtcIsac_EncodeLar(double* LPCCoef, Bitstr* streamdata,
998                           IsacSaveEncoderData* encData) {
999   int j, k, n, pos, pos2, poss, offss, offs2;
1000   int index_s[KLT_ORDER_SHAPE];
1001   int index_ovr_s[KLT_ORDER_SHAPE];
1002   double tmpcoeffs_s[KLT_ORDER_SHAPE];
1003   double tmpcoeffs2_s[KLT_ORDER_SHAPE];
1004   double sum;
1005   const int kModel = 0;
1006 
1007   /* Mean removal and scaling. */
1008   poss = 0;
1009   pos = 0;
1010   for (k = 0; k < SUBFRAMES; k++) {
1011     /* First two element are gains, move over them. */
1012     pos += 2;
1013 
1014     /* Low-band LAR coefficients. */
1015     for (n = 0; n < LPC_LOBAND_ORDER; n++, poss++, pos++) {
1016       tmpcoeffs_s[poss] = LPCCoef[pos] - WebRtcIsac_kLpcMeansShape[poss];
1017       tmpcoeffs_s[poss] *= LPC_LOBAND_SCALE;
1018     }
1019 
1020     /* High-band LAR coefficients. */
1021     for (n = 0; n < LPC_HIBAND_ORDER; n++, poss++, pos++) {
1022       tmpcoeffs_s[poss] = LPCCoef[pos] - WebRtcIsac_kLpcMeansShape[poss];
1023       tmpcoeffs_s[poss] *= LPC_HIBAND_SCALE;
1024     }
1025   }
1026 
1027   /* KLT  */
1028 
1029   /* Left transform. */
1030   offss = 0;
1031   for (j = 0; j < SUBFRAMES; j++) {
1032     poss = offss;
1033     for (k = 0; k < LPC_SHAPE_ORDER; k++) {
1034       sum = 0;
1035       pos = offss;
1036       pos2 = k;
1037       for (n = 0; n < LPC_SHAPE_ORDER; n++) {
1038         sum += tmpcoeffs_s[pos++] * WebRtcIsac_kKltT1Shape[pos2];
1039         pos2 += LPC_SHAPE_ORDER;
1040       }
1041       tmpcoeffs2_s[poss++] = sum;
1042     }
1043     offss += LPC_SHAPE_ORDER;
1044   }
1045 
1046   /* Right transform. */
1047   offss = 0;
1048   offs2 = 0;
1049   for (j = 0; j < SUBFRAMES; j++) {
1050     poss = offss;
1051     for (k = 0; k < LPC_SHAPE_ORDER; k++) {
1052       sum = 0;
1053       pos = k;
1054       pos2 = offs2;
1055       for (n = 0; n < SUBFRAMES; n++) {
1056         sum += tmpcoeffs2_s[pos] * WebRtcIsac_kKltT2Shape[pos2++];
1057         pos += LPC_SHAPE_ORDER;
1058       }
1059       tmpcoeffs_s[poss++] = sum;
1060     }
1061     offs2 += SUBFRAMES;
1062     offss += LPC_SHAPE_ORDER;
1063   }
1064 
1065   /* Quantize coefficients. */
1066   for (k = 0; k < KLT_ORDER_SHAPE; k++) {
1067     index_s[k] = (WebRtcIsac_lrint(tmpcoeffs_s[k] / KLT_STEPSIZE)) +
1068         WebRtcIsac_kQKltQuantMinShape[k];
1069     if (index_s[k] < 0) {
1070       index_s[k] = 0;
1071     } else if (index_s[k] > WebRtcIsac_kQKltMaxIndShape[k]) {
1072       index_s[k] = WebRtcIsac_kQKltMaxIndShape[k];
1073     }
1074     index_ovr_s[k] = WebRtcIsac_kQKltOffsetShape[k] + index_s[k];
1075   }
1076 
1077 
1078   /* Only one model remains in this version of the code, kModel = 0. We
1079    * are keeping for bit-streams to be backward compatible. */
1080   /* entropy coding of model number */
1081   WebRtcIsac_EncHistMulti(streamdata, &kModel, WebRtcIsac_kQKltModelCdfPtr, 1);
1082 
1083   /* Save data for creation of multiple bit streams */
1084   /* Entropy coding of quantization indices - shape only. */
1085   WebRtcIsac_EncHistMulti(streamdata, index_s, WebRtcIsac_kQKltCdfPtrShape,
1086                           KLT_ORDER_SHAPE);
1087 
1088   /* Save data for creation of multiple bit streams. */
1089   for (k = 0; k < KLT_ORDER_SHAPE; k++) {
1090     encData->LPCindex_s[KLT_ORDER_SHAPE * encData->startIdx + k] = index_s[k];
1091   }
1092 
1093   /* Find quantization levels for shape coefficients. */
1094   for (k = 0; k < KLT_ORDER_SHAPE; k++) {
1095     tmpcoeffs_s[k] = WebRtcIsac_kQKltLevelsShape[index_ovr_s[k]];
1096   }
1097   /* Inverse KLT.  */
1098   /* Left transform, transpose matrix.! */
1099   offss = 0;
1100   poss = 0;
1101   for (j = 0; j < SUBFRAMES; j++) {
1102     offs2 = 0;
1103     for (k = 0; k < LPC_SHAPE_ORDER; k++) {
1104       sum = 0;
1105       pos = offss;
1106       pos2 = offs2;
1107       for (n = 0; n < LPC_SHAPE_ORDER; n++) {
1108         sum += tmpcoeffs_s[pos++] * WebRtcIsac_kKltT1Shape[pos2++];
1109       }
1110       tmpcoeffs2_s[poss++] = sum;
1111       offs2 += LPC_SHAPE_ORDER;
1112     }
1113     offss += LPC_SHAPE_ORDER;
1114   }
1115 
1116   /* Right transform, Transpose matrix */
1117   offss = 0;
1118   poss = 0;
1119   for (j = 0; j < SUBFRAMES; j++) {
1120     poss = offss;
1121     for (k = 0; k < LPC_SHAPE_ORDER; k++) {
1122       sum = 0;
1123       pos = k;
1124       pos2 = j;
1125       for (n = 0; n < SUBFRAMES; n++) {
1126         sum += tmpcoeffs2_s[pos] * WebRtcIsac_kKltT2Shape[pos2];
1127         pos += LPC_SHAPE_ORDER;
1128         pos2 += SUBFRAMES;
1129       }
1130       tmpcoeffs_s[poss++] = sum;
1131     }
1132     offss += LPC_SHAPE_ORDER;
1133   }
1134 
1135   /* Scaling, mean addition, and gain restoration. */
1136   poss = 0;
1137   pos = 0;
1138   for (k = 0; k < SUBFRAMES; k++) {
1139     /* Ignore gains. */
1140     pos += 2;
1141 
1142     /* Low band LAR coefficients. */
1143     for (n = 0; n < LPC_LOBAND_ORDER; n++, pos++, poss++) {
1144       LPCCoef[pos] = tmpcoeffs_s[poss] / LPC_LOBAND_SCALE;
1145       LPCCoef[pos] += WebRtcIsac_kLpcMeansShape[poss];
1146     }
1147 
1148     /* High band LAR coefficients. */
1149     for (n = 0; n < LPC_HIBAND_ORDER; n++, pos++, poss++) {
1150       LPCCoef[pos] = tmpcoeffs_s[poss] / LPC_HIBAND_SCALE;
1151       LPCCoef[pos] += WebRtcIsac_kLpcMeansShape[poss];
1152     }
1153   }
1154 }
1155 
1156 
WebRtcIsac_EncodeLpcLb(double * LPCCoef_lo,double * LPCCoef_hi,Bitstr * streamdata,IsacSaveEncoderData * encData)1157 void WebRtcIsac_EncodeLpcLb(double* LPCCoef_lo, double* LPCCoef_hi,
1158                             Bitstr* streamdata, IsacSaveEncoderData* encData) {
1159   double lars[KLT_ORDER_GAIN + KLT_ORDER_SHAPE];
1160   int k;
1161 
1162   WebRtcIsac_Poly2Lar(LPCCoef_lo, ORDERLO, LPCCoef_hi, ORDERHI, SUBFRAMES,
1163                       lars);
1164   WebRtcIsac_EncodeLar(lars, streamdata, encData);
1165   WebRtcIsac_Lar2Poly(lars, LPCCoef_lo, ORDERLO, LPCCoef_hi, ORDERHI,
1166                       SUBFRAMES);
1167   /* Save data for creation of multiple bit streams (and transcoding). */
1168   for (k = 0; k < (ORDERLO + 1)*SUBFRAMES; k++) {
1169     encData->LPCcoeffs_lo[(ORDERLO + 1)*SUBFRAMES * encData->startIdx + k] =
1170         LPCCoef_lo[k];
1171   }
1172   for (k = 0; k < (ORDERHI + 1)*SUBFRAMES; k++) {
1173     encData->LPCcoeffs_hi[(ORDERHI + 1)*SUBFRAMES * encData->startIdx + k] =
1174         LPCCoef_hi[k];
1175   }
1176 }
1177 
1178 
WebRtcIsac_EncodeLpcUB(double * lpcVecs,Bitstr * streamdata,double * interpolLPCCoeff,int16_t bandwidth,ISACUBSaveEncDataStruct * encData)1179 int16_t WebRtcIsac_EncodeLpcUB(double* lpcVecs, Bitstr* streamdata,
1180                                double* interpolLPCCoeff,
1181                                int16_t bandwidth,
1182                                      ISACUBSaveEncDataStruct* encData) {
1183   double    U[UB_LPC_ORDER * UB16_LPC_VEC_PER_FRAME];
1184   int     idx[UB_LPC_ORDER * UB16_LPC_VEC_PER_FRAME];
1185   int interpolCntr;
1186 
1187   WebRtcIsac_Poly2LarUB(lpcVecs, bandwidth);
1188   WebRtcIsac_RemoveLarMean(lpcVecs, bandwidth);
1189   WebRtcIsac_DecorrelateIntraVec(lpcVecs, U, bandwidth);
1190   WebRtcIsac_DecorrelateInterVec(U, lpcVecs, bandwidth);
1191   WebRtcIsac_QuantizeUncorrLar(lpcVecs, idx, bandwidth);
1192 
1193   WebRtcIsac_CorrelateInterVec(lpcVecs, U, bandwidth);
1194   WebRtcIsac_CorrelateIntraVec(U, lpcVecs, bandwidth);
1195   WebRtcIsac_AddLarMean(lpcVecs, bandwidth);
1196 
1197   switch (bandwidth) {
1198     case isac12kHz: {
1199       /* Store the indices to be used for multiple encoding. */
1200       memcpy(encData->indexLPCShape, idx, UB_LPC_ORDER *
1201              UB_LPC_VEC_PER_FRAME * sizeof(int));
1202       WebRtcIsac_EncHistMulti(streamdata, idx, WebRtcIsac_kLpcShapeCdfMatUb12,
1203                               UB_LPC_ORDER * UB_LPC_VEC_PER_FRAME);
1204       for (interpolCntr = 0; interpolCntr < UB_INTERPOL_SEGMENTS;
1205           interpolCntr++) {
1206         WebRtcIsac_Lar2PolyInterpolUB(lpcVecs, interpolLPCCoeff,
1207                                       kLpcVecPerSegmentUb12 + 1);
1208         lpcVecs += UB_LPC_ORDER;
1209         interpolLPCCoeff += (kLpcVecPerSegmentUb12 * (UB_LPC_ORDER + 1));
1210       }
1211       break;
1212     }
1213     case isac16kHz: {
1214       /* Store the indices to be used for multiple encoding. */
1215       memcpy(encData->indexLPCShape, idx, UB_LPC_ORDER *
1216              UB16_LPC_VEC_PER_FRAME * sizeof(int));
1217       WebRtcIsac_EncHistMulti(streamdata, idx, WebRtcIsac_kLpcShapeCdfMatUb16,
1218                               UB_LPC_ORDER * UB16_LPC_VEC_PER_FRAME);
1219       for (interpolCntr = 0; interpolCntr < UB16_INTERPOL_SEGMENTS;
1220           interpolCntr++) {
1221         WebRtcIsac_Lar2PolyInterpolUB(lpcVecs, interpolLPCCoeff,
1222                                       kLpcVecPerSegmentUb16 + 1);
1223         lpcVecs += UB_LPC_ORDER;
1224         interpolLPCCoeff += (kLpcVecPerSegmentUb16 * (UB_LPC_ORDER + 1));
1225       }
1226       break;
1227     }
1228     default:
1229       return -1;
1230   }
1231   return 0;
1232 }
1233 
WebRtcIsac_EncodeLpcGainLb(double * LPCCoef_lo,double * LPCCoef_hi,Bitstr * streamdata,IsacSaveEncoderData * encData)1234 void WebRtcIsac_EncodeLpcGainLb(double* LPCCoef_lo, double* LPCCoef_hi,
1235                                 Bitstr* streamdata,
1236                                 IsacSaveEncoderData* encData) {
1237   int j, k, n, pos, pos2, posg, offsg, offs2;
1238   int index_g[KLT_ORDER_GAIN];
1239   int index_ovr_g[KLT_ORDER_GAIN];
1240   double tmpcoeffs_g[KLT_ORDER_GAIN];
1241   double tmpcoeffs2_g[KLT_ORDER_GAIN];
1242   double sum;
1243   /* log gains, mean removal and scaling */
1244   posg = 0;
1245   for (k = 0; k < SUBFRAMES; k++) {
1246     tmpcoeffs_g[posg] = log(LPCCoef_lo[(LPC_LOBAND_ORDER + 1) * k]);
1247     tmpcoeffs_g[posg] -= WebRtcIsac_kLpcMeansGain[posg];
1248     tmpcoeffs_g[posg] *= LPC_GAIN_SCALE;
1249     posg++;
1250     tmpcoeffs_g[posg] = log(LPCCoef_hi[(LPC_HIBAND_ORDER + 1) * k]);
1251     tmpcoeffs_g[posg] -= WebRtcIsac_kLpcMeansGain[posg];
1252     tmpcoeffs_g[posg] *= LPC_GAIN_SCALE;
1253     posg++;
1254   }
1255 
1256   /* KLT  */
1257 
1258   /* Left transform. */
1259   offsg = 0;
1260   for (j = 0; j < SUBFRAMES; j++) {
1261     posg = offsg;
1262     for (k = 0; k < LPC_GAIN_ORDER; k++) {
1263       sum = 0;
1264       pos = offsg;
1265       pos2 = k;
1266       for (n = 0; n < LPC_GAIN_ORDER; n++) {
1267         sum += tmpcoeffs_g[pos++] * WebRtcIsac_kKltT1Gain[pos2];
1268         pos2 += LPC_GAIN_ORDER;
1269       }
1270       tmpcoeffs2_g[posg++] = sum;
1271     }
1272     offsg += LPC_GAIN_ORDER;
1273   }
1274 
1275   /* Right transform. */
1276   offsg = 0;
1277   offs2 = 0;
1278   for (j = 0; j < SUBFRAMES; j++) {
1279     posg = offsg;
1280     for (k = 0; k < LPC_GAIN_ORDER; k++) {
1281       sum = 0;
1282       pos = k;
1283       pos2 = offs2;
1284       for (n = 0; n < SUBFRAMES; n++) {
1285         sum += tmpcoeffs2_g[pos] * WebRtcIsac_kKltT2Gain[pos2++];
1286         pos += LPC_GAIN_ORDER;
1287       }
1288       tmpcoeffs_g[posg++] = sum;
1289     }
1290     offs2 += SUBFRAMES;
1291     offsg += LPC_GAIN_ORDER;
1292   }
1293 
1294   /* Quantize coefficients. */
1295   for (k = 0; k < KLT_ORDER_GAIN; k++) {
1296     /* Get index. */
1297     pos2 = WebRtcIsac_lrint(tmpcoeffs_g[k] / KLT_STEPSIZE);
1298     index_g[k] = (pos2) + WebRtcIsac_kQKltQuantMinGain[k];
1299     if (index_g[k] < 0) {
1300       index_g[k] = 0;
1301     } else if (index_g[k] > WebRtcIsac_kQKltMaxIndGain[k]) {
1302       index_g[k] = WebRtcIsac_kQKltMaxIndGain[k];
1303     }
1304     index_ovr_g[k] = WebRtcIsac_kQKltOffsetGain[k] + index_g[k];
1305 
1306     /* Find quantization levels for coefficients. */
1307     tmpcoeffs_g[k] = WebRtcIsac_kQKltLevelsGain[index_ovr_g[k]];
1308 
1309     /* Save data for creation of multiple bit streams. */
1310     encData->LPCindex_g[KLT_ORDER_GAIN * encData->startIdx + k] = index_g[k];
1311   }
1312 
1313   /* Entropy coding of quantization indices - gain. */
1314   WebRtcIsac_EncHistMulti(streamdata, index_g, WebRtcIsac_kQKltCdfPtrGain,
1315                           KLT_ORDER_GAIN);
1316 
1317   /* Find quantization levels for coefficients. */
1318   /* Left transform. */
1319   offsg = 0;
1320   posg = 0;
1321   for (j = 0; j < SUBFRAMES; j++) {
1322     offs2 = 0;
1323     for (k = 0; k < LPC_GAIN_ORDER; k++) {
1324       sum = 0;
1325       pos = offsg;
1326       pos2 = offs2;
1327       for (n = 0; n < LPC_GAIN_ORDER; n++)
1328         sum += tmpcoeffs_g[pos++] * WebRtcIsac_kKltT1Gain[pos2++];
1329       tmpcoeffs2_g[posg++] = sum;
1330       offs2 += LPC_GAIN_ORDER;
1331     }
1332     offsg += LPC_GAIN_ORDER;
1333   }
1334 
1335   /* Right transform, transpose matrix. */
1336   offsg = 0;
1337   posg = 0;
1338   for (j = 0; j < SUBFRAMES; j++) {
1339     posg = offsg;
1340     for (k = 0; k < LPC_GAIN_ORDER; k++) {
1341       sum = 0;
1342       pos = k;
1343       pos2 = j;
1344       for (n = 0; n < SUBFRAMES; n++) {
1345         sum += tmpcoeffs2_g[pos] * WebRtcIsac_kKltT2Gain[pos2];
1346         pos += LPC_GAIN_ORDER;
1347         pos2 += SUBFRAMES;
1348       }
1349       tmpcoeffs_g[posg++] = sum;
1350     }
1351     offsg += LPC_GAIN_ORDER;
1352   }
1353 
1354 
1355   /* Scaling, mean addition, and gain restoration. */
1356   posg = 0;
1357   for (k = 0; k < SUBFRAMES; k++) {
1358     sum = tmpcoeffs_g[posg] / LPC_GAIN_SCALE;
1359     sum += WebRtcIsac_kLpcMeansGain[posg];
1360     LPCCoef_lo[k * (LPC_LOBAND_ORDER + 1)] = exp(sum);
1361     pos++;
1362     posg++;
1363     sum = tmpcoeffs_g[posg] / LPC_GAIN_SCALE;
1364     sum += WebRtcIsac_kLpcMeansGain[posg];
1365     LPCCoef_hi[k * (LPC_HIBAND_ORDER + 1)] = exp(sum);
1366     pos++;
1367     posg++;
1368   }
1369 
1370 }
1371 
WebRtcIsac_EncodeLpcGainUb(double * lpGains,Bitstr * streamdata,int * lpcGainIndex)1372 void WebRtcIsac_EncodeLpcGainUb(double* lpGains, Bitstr* streamdata,
1373                                 int* lpcGainIndex) {
1374   double U[UB_LPC_GAIN_DIM];
1375   int idx[UB_LPC_GAIN_DIM];
1376   WebRtcIsac_ToLogDomainRemoveMean(lpGains);
1377   WebRtcIsac_DecorrelateLPGain(lpGains, U);
1378   WebRtcIsac_QuantizeLpcGain(U, idx);
1379   /* Store the index for re-encoding for FEC. */
1380   memcpy(lpcGainIndex, idx, UB_LPC_GAIN_DIM * sizeof(int));
1381   WebRtcIsac_CorrelateLpcGain(U, lpGains);
1382   WebRtcIsac_AddMeanToLinearDomain(lpGains);
1383   WebRtcIsac_EncHistMulti(streamdata, idx, WebRtcIsac_kLpcGainCdfMat,
1384                           UB_LPC_GAIN_DIM);
1385 }
1386 
1387 
WebRtcIsac_StoreLpcGainUb(double * lpGains,Bitstr * streamdata)1388 void WebRtcIsac_StoreLpcGainUb(double* lpGains, Bitstr* streamdata) {
1389   double U[UB_LPC_GAIN_DIM];
1390   int idx[UB_LPC_GAIN_DIM];
1391   WebRtcIsac_ToLogDomainRemoveMean(lpGains);
1392   WebRtcIsac_DecorrelateLPGain(lpGains, U);
1393   WebRtcIsac_QuantizeLpcGain(U, idx);
1394   WebRtcIsac_EncHistMulti(streamdata, idx, WebRtcIsac_kLpcGainCdfMat,
1395                           UB_LPC_GAIN_DIM);
1396 }
1397 
1398 
1399 
WebRtcIsac_DecodeLpcGainUb(double * lpGains,Bitstr * streamdata)1400 int16_t WebRtcIsac_DecodeLpcGainUb(double* lpGains, Bitstr* streamdata) {
1401   double U[UB_LPC_GAIN_DIM];
1402   int idx[UB_LPC_GAIN_DIM];
1403   int err;
1404   err = WebRtcIsac_DecHistOneStepMulti(idx, streamdata,
1405                                        WebRtcIsac_kLpcGainCdfMat,
1406                                        WebRtcIsac_kLpcGainEntropySearch,
1407                                        UB_LPC_GAIN_DIM);
1408   if (err < 0) {
1409     return -1;
1410   }
1411   WebRtcIsac_DequantizeLpcGain(idx, U);
1412   WebRtcIsac_CorrelateLpcGain(U, lpGains);
1413   WebRtcIsac_AddMeanToLinearDomain(lpGains);
1414   return 0;
1415 }
1416 
1417 
1418 
1419 /* decode & dequantize RC */
WebRtcIsac_DecodeRc(Bitstr * streamdata,int16_t * RCQ15)1420 int WebRtcIsac_DecodeRc(Bitstr* streamdata, int16_t* RCQ15) {
1421   int k, err;
1422   int index[AR_ORDER];
1423 
1424   /* entropy decoding of quantization indices */
1425   err = WebRtcIsac_DecHistOneStepMulti(index, streamdata,
1426                                        WebRtcIsac_kQArRcCdfPtr,
1427                                        WebRtcIsac_kQArRcInitIndex, AR_ORDER);
1428   if (err < 0)
1429     return err;
1430 
1431   /* find quantization levels for reflection coefficients */
1432   for (k = 0; k < AR_ORDER; k++) {
1433     RCQ15[k] = *(WebRtcIsac_kQArRcLevelsPtr[k] + index[k]);
1434   }
1435   return 0;
1436 }
1437 
1438 
1439 /* quantize & code RC */
WebRtcIsac_EncodeRc(int16_t * RCQ15,Bitstr * streamdata)1440 void WebRtcIsac_EncodeRc(int16_t* RCQ15, Bitstr* streamdata) {
1441   int k;
1442   int index[AR_ORDER];
1443 
1444   /* quantize reflection coefficients (add noise feedback?) */
1445   for (k = 0; k < AR_ORDER; k++) {
1446     index[k] = WebRtcIsac_kQArRcInitIndex[k];
1447     // The safe-guards in following while conditions are to suppress gcc 4.8.3
1448     // warnings, Issue 2888. Otherwise, first and last elements of
1449     // |WebRtcIsac_kQArBoundaryLevels| are such that the following search
1450     // *never* cause an out-of-boundary read.
1451     if (RCQ15[k] > WebRtcIsac_kQArBoundaryLevels[index[k]]) {
1452       while (index[k] + 1 < NUM_AR_RC_QUANT_BAUNDARY &&
1453         RCQ15[k] > WebRtcIsac_kQArBoundaryLevels[index[k] + 1]) {
1454         index[k]++;
1455       }
1456     } else {
1457       while (index[k] > 0 &&
1458         RCQ15[k] < WebRtcIsac_kQArBoundaryLevels[--index[k]]) ;
1459     }
1460     RCQ15[k] = *(WebRtcIsac_kQArRcLevelsPtr[k] + index[k]);
1461   }
1462 
1463   /* entropy coding of quantization indices */
1464   WebRtcIsac_EncHistMulti(streamdata, index, WebRtcIsac_kQArRcCdfPtr, AR_ORDER);
1465 }
1466 
1467 
1468 /* decode & dequantize squared Gain */
WebRtcIsac_DecodeGain2(Bitstr * streamdata,int32_t * gainQ10)1469 int WebRtcIsac_DecodeGain2(Bitstr* streamdata, int32_t* gainQ10) {
1470   int index, err;
1471 
1472   /* entropy decoding of quantization index */
1473   err = WebRtcIsac_DecHistOneStepMulti(&index, streamdata,
1474                                        WebRtcIsac_kQGainCdf_ptr,
1475                                        WebRtcIsac_kQGainInitIndex, 1);
1476   if (err < 0) {
1477     return err;
1478   }
1479   /* find quantization level */
1480   *gainQ10 = WebRtcIsac_kQGain2Levels[index];
1481   return 0;
1482 }
1483 
1484 
1485 /* quantize & code squared Gain */
WebRtcIsac_EncodeGain2(int32_t * gainQ10,Bitstr * streamdata)1486 int WebRtcIsac_EncodeGain2(int32_t* gainQ10, Bitstr* streamdata) {
1487   int index;
1488 
1489   /* find quantization index */
1490   index = WebRtcIsac_kQGainInitIndex[0];
1491   if (*gainQ10 > WebRtcIsac_kQGain2BoundaryLevels[index]) {
1492     while (*gainQ10 > WebRtcIsac_kQGain2BoundaryLevels[index + 1]) {
1493       index++;
1494     }
1495   } else {
1496     while (*gainQ10 < WebRtcIsac_kQGain2BoundaryLevels[--index]) ;
1497   }
1498   /* De-quantize */
1499   *gainQ10 = WebRtcIsac_kQGain2Levels[index];
1500 
1501   /* entropy coding of quantization index */
1502   WebRtcIsac_EncHistMulti(streamdata, &index, WebRtcIsac_kQGainCdf_ptr, 1);
1503   return 0;
1504 }
1505 
1506 
1507 /* code and decode Pitch Gains and Lags functions */
1508 
1509 /* decode & dequantize Pitch Gains */
WebRtcIsac_DecodePitchGain(Bitstr * streamdata,int16_t * PitchGains_Q12)1510 int WebRtcIsac_DecodePitchGain(Bitstr* streamdata,
1511                                int16_t* PitchGains_Q12) {
1512   int index_comb, err;
1513   const uint16_t* WebRtcIsac_kQPitchGainCdf_ptr[1];
1514 
1515   /* Entropy decoding of quantization indices */
1516   *WebRtcIsac_kQPitchGainCdf_ptr = WebRtcIsac_kQPitchGainCdf;
1517   err = WebRtcIsac_DecHistBisectMulti(&index_comb, streamdata,
1518                                       WebRtcIsac_kQPitchGainCdf_ptr,
1519                                       WebRtcIsac_kQCdfTableSizeGain, 1);
1520   /* Error check, Q_mean_Gain.. tables are of size 144 */
1521   if ((err < 0) || (index_comb < 0) || (index_comb >= 144)) {
1522     return -ISAC_RANGE_ERROR_DECODE_PITCH_GAIN;
1523   }
1524   /* De-quantize back to pitch gains by table look-up. */
1525   PitchGains_Q12[0] = WebRtcIsac_kQMeanGain1Q12[index_comb];
1526   PitchGains_Q12[1] = WebRtcIsac_kQMeanGain2Q12[index_comb];
1527   PitchGains_Q12[2] = WebRtcIsac_kQMeanGain3Q12[index_comb];
1528   PitchGains_Q12[3] = WebRtcIsac_kQMeanGain4Q12[index_comb];
1529   return 0;
1530 }
1531 
1532 
1533 /* Quantize & code Pitch Gains. */
WebRtcIsac_EncodePitchGain(int16_t * PitchGains_Q12,Bitstr * streamdata,IsacSaveEncoderData * encData)1534 void WebRtcIsac_EncodePitchGain(int16_t* PitchGains_Q12,
1535                                 Bitstr* streamdata,
1536                                 IsacSaveEncoderData* encData) {
1537   int k, j;
1538   double C;
1539   double S[PITCH_SUBFRAMES];
1540   int index[3];
1541   int index_comb;
1542   const uint16_t* WebRtcIsac_kQPitchGainCdf_ptr[1];
1543   double PitchGains[PITCH_SUBFRAMES] = {0, 0, 0, 0};
1544 
1545   /* Take the asin. */
1546   for (k = 0; k < PITCH_SUBFRAMES; k++) {
1547     PitchGains[k] = ((float)PitchGains_Q12[k]) / 4096;
1548     S[k] = asin(PitchGains[k]);
1549   }
1550 
1551   /* Find quantization index; only for the first three
1552    * transform coefficients. */
1553   for (k = 0; k < 3; k++) {
1554     /*  transform */
1555     C = 0.0;
1556     for (j = 0; j < PITCH_SUBFRAMES; j++) {
1557       C += WebRtcIsac_kTransform[k][j] * S[j];
1558     }
1559     /* Quantize */
1560     index[k] = WebRtcIsac_lrint(C / PITCH_GAIN_STEPSIZE);
1561 
1562     /* Check that the index is not outside the boundaries of the table. */
1563     if (index[k] < WebRtcIsac_kIndexLowerLimitGain[k]) {
1564       index[k] = WebRtcIsac_kIndexLowerLimitGain[k];
1565     } else if (index[k] > WebRtcIsac_kIndexUpperLimitGain[k]) {
1566       index[k] = WebRtcIsac_kIndexUpperLimitGain[k];
1567     }
1568     index[k] -= WebRtcIsac_kIndexLowerLimitGain[k];
1569   }
1570 
1571   /* Calculate unique overall index. */
1572   index_comb = WebRtcIsac_kIndexMultsGain[0] * index[0] +
1573       WebRtcIsac_kIndexMultsGain[1] * index[1] + index[2];
1574 
1575   /* unquantize back to pitch gains by table look-up */
1576   PitchGains_Q12[0] = WebRtcIsac_kQMeanGain1Q12[index_comb];
1577   PitchGains_Q12[1] = WebRtcIsac_kQMeanGain2Q12[index_comb];
1578   PitchGains_Q12[2] = WebRtcIsac_kQMeanGain3Q12[index_comb];
1579   PitchGains_Q12[3] = WebRtcIsac_kQMeanGain4Q12[index_comb];
1580 
1581   /* entropy coding of quantization pitch gains */
1582   *WebRtcIsac_kQPitchGainCdf_ptr = WebRtcIsac_kQPitchGainCdf;
1583   WebRtcIsac_EncHistMulti(streamdata, &index_comb,
1584                           WebRtcIsac_kQPitchGainCdf_ptr, 1);
1585   encData->pitchGain_index[encData->startIdx] = index_comb;
1586 }
1587 
1588 
1589 
1590 /* Pitch LAG */
1591 /* Decode & de-quantize Pitch Lags. */
WebRtcIsac_DecodePitchLag(Bitstr * streamdata,int16_t * PitchGain_Q12,double * PitchLags)1592 int WebRtcIsac_DecodePitchLag(Bitstr* streamdata, int16_t* PitchGain_Q12,
1593                               double* PitchLags) {
1594   int k, err;
1595   double StepSize;
1596   double C;
1597   int index[PITCH_SUBFRAMES];
1598   double mean_gain;
1599   const double* mean_val2, *mean_val3, *mean_val4;
1600   const int16_t* lower_limit;
1601   const uint16_t* init_index;
1602   const uint16_t* cdf_size;
1603   const uint16_t** cdf;
1604   double PitchGain[4] = {0, 0, 0, 0};
1605 
1606   /* compute mean pitch gain */
1607   mean_gain = 0.0;
1608   for (k = 0; k < 4; k++) {
1609     PitchGain[k] = ((float)PitchGain_Q12[k]) / 4096;
1610     mean_gain += PitchGain[k];
1611   }
1612   mean_gain /= 4.0;
1613 
1614   /* voicing classification. */
1615   if (mean_gain < 0.2) {
1616     StepSize = WebRtcIsac_kQPitchLagStepsizeLo;
1617     cdf = WebRtcIsac_kQPitchLagCdfPtrLo;
1618     cdf_size = WebRtcIsac_kQPitchLagCdfSizeLo;
1619     mean_val2 = WebRtcIsac_kQMeanLag2Lo;
1620     mean_val3 = WebRtcIsac_kQMeanLag3Lo;
1621     mean_val4 = WebRtcIsac_kQMeanLag4Lo;
1622     lower_limit = WebRtcIsac_kQIndexLowerLimitLagLo;
1623     init_index = WebRtcIsac_kQInitIndexLagLo;
1624   } else if (mean_gain < 0.4) {
1625     StepSize = WebRtcIsac_kQPitchLagStepsizeMid;
1626     cdf = WebRtcIsac_kQPitchLagCdfPtrMid;
1627     cdf_size = WebRtcIsac_kQPitchLagCdfSizeMid;
1628     mean_val2 = WebRtcIsac_kQMeanLag2Mid;
1629     mean_val3 = WebRtcIsac_kQMeanLag3Mid;
1630     mean_val4 = WebRtcIsac_kQMeanLag4Mid;
1631     lower_limit = WebRtcIsac_kQIndexLowerLimitLagMid;
1632     init_index = WebRtcIsac_kQInitIndexLagMid;
1633   } else {
1634     StepSize = WebRtcIsac_kQPitchLagStepsizeHi;
1635     cdf = WebRtcIsac_kQPitchLagCdfPtrHi;
1636     cdf_size = WebRtcIsac_kQPitchLagCdfSizeHi;
1637     mean_val2 = WebRtcIsac_kQMeanLag2Hi;
1638     mean_val3 = WebRtcIsac_kQMeanLag3Hi;
1639     mean_val4 = WebRtcIsac_kQMeanLag4Hi;
1640     lower_limit = WebRtcIsac_kQindexLowerLimitLagHi;
1641     init_index = WebRtcIsac_kQInitIndexLagHi;
1642   }
1643 
1644   /* Entropy decoding of quantization indices. */
1645   err = WebRtcIsac_DecHistBisectMulti(index, streamdata, cdf, cdf_size, 1);
1646   if ((err < 0) || (index[0] < 0)) {
1647     return -ISAC_RANGE_ERROR_DECODE_PITCH_LAG;
1648   }
1649   err = WebRtcIsac_DecHistOneStepMulti(index + 1, streamdata, cdf + 1,
1650                                        init_index, 3);
1651   if (err < 0) {
1652     return -ISAC_RANGE_ERROR_DECODE_PITCH_LAG;
1653   }
1654 
1655   /* Unquantize back to transform coefficients and do the inverse transform:
1656    * S = T'*C. */
1657   C = (index[0] + lower_limit[0]) * StepSize;
1658   for (k = 0; k < PITCH_SUBFRAMES; k++) {
1659     PitchLags[k] = WebRtcIsac_kTransformTranspose[k][0] * C;
1660   }
1661   C = mean_val2[index[1]];
1662   for (k = 0; k < PITCH_SUBFRAMES; k++) {
1663     PitchLags[k] += WebRtcIsac_kTransformTranspose[k][1] * C;
1664   }
1665   C = mean_val3[index[2]];
1666   for (k = 0; k < PITCH_SUBFRAMES; k++) {
1667     PitchLags[k] += WebRtcIsac_kTransformTranspose[k][2] * C;
1668   }
1669   C = mean_val4[index[3]];
1670   for (k = 0; k < PITCH_SUBFRAMES; k++) {
1671     PitchLags[k] += WebRtcIsac_kTransformTranspose[k][3] * C;
1672   }
1673   return 0;
1674 }
1675 
1676 
1677 
1678 /* Quantize & code pitch lags. */
WebRtcIsac_EncodePitchLag(double * PitchLags,int16_t * PitchGain_Q12,Bitstr * streamdata,IsacSaveEncoderData * encData)1679 void WebRtcIsac_EncodePitchLag(double* PitchLags, int16_t* PitchGain_Q12,
1680                                Bitstr* streamdata,
1681                                IsacSaveEncoderData* encData) {
1682   int k, j;
1683   double StepSize;
1684   double C;
1685   int index[PITCH_SUBFRAMES];
1686   double mean_gain;
1687   const double* mean_val2, *mean_val3, *mean_val4;
1688   const int16_t* lower_limit, *upper_limit;
1689   const uint16_t** cdf;
1690   double PitchGain[4] = {0, 0, 0, 0};
1691 
1692   /* compute mean pitch gain */
1693   mean_gain = 0.0;
1694   for (k = 0; k < 4; k++) {
1695     PitchGain[k] = ((float)PitchGain_Q12[k]) / 4096;
1696     mean_gain += PitchGain[k];
1697   }
1698   mean_gain /= 4.0;
1699 
1700   /* Save data for creation of multiple bit streams */
1701   encData->meanGain[encData->startIdx] = mean_gain;
1702 
1703   /* Voicing classification. */
1704   if (mean_gain < 0.2) {
1705     StepSize = WebRtcIsac_kQPitchLagStepsizeLo;
1706     cdf = WebRtcIsac_kQPitchLagCdfPtrLo;
1707     mean_val2 = WebRtcIsac_kQMeanLag2Lo;
1708     mean_val3 = WebRtcIsac_kQMeanLag3Lo;
1709     mean_val4 = WebRtcIsac_kQMeanLag4Lo;
1710     lower_limit = WebRtcIsac_kQIndexLowerLimitLagLo;
1711     upper_limit = WebRtcIsac_kQIndexUpperLimitLagLo;
1712   } else if (mean_gain < 0.4) {
1713     StepSize = WebRtcIsac_kQPitchLagStepsizeMid;
1714     cdf = WebRtcIsac_kQPitchLagCdfPtrMid;
1715     mean_val2 = WebRtcIsac_kQMeanLag2Mid;
1716     mean_val3 = WebRtcIsac_kQMeanLag3Mid;
1717     mean_val4 = WebRtcIsac_kQMeanLag4Mid;
1718     lower_limit = WebRtcIsac_kQIndexLowerLimitLagMid;
1719     upper_limit = WebRtcIsac_kQIndexUpperLimitLagMid;
1720   } else {
1721     StepSize = WebRtcIsac_kQPitchLagStepsizeHi;
1722     cdf = WebRtcIsac_kQPitchLagCdfPtrHi;
1723     mean_val2 = WebRtcIsac_kQMeanLag2Hi;
1724     mean_val3 = WebRtcIsac_kQMeanLag3Hi;
1725     mean_val4 = WebRtcIsac_kQMeanLag4Hi;
1726     lower_limit = WebRtcIsac_kQindexLowerLimitLagHi;
1727     upper_limit = WebRtcIsac_kQindexUpperLimitLagHi;
1728   }
1729 
1730   /* find quantization index */
1731   for (k = 0; k < 4; k++) {
1732     /*  transform */
1733     C = 0.0;
1734     for (j = 0; j < PITCH_SUBFRAMES; j++) {
1735       C += WebRtcIsac_kTransform[k][j] * PitchLags[j];
1736     }
1737     /* quantize */
1738     index[k] = WebRtcIsac_lrint(C / StepSize);
1739 
1740     /* check that the index is not outside the boundaries of the table */
1741     if (index[k] < lower_limit[k]) {
1742       index[k] = lower_limit[k];
1743     } else if (index[k] > upper_limit[k]) index[k] = upper_limit[k]; {
1744       index[k] -= lower_limit[k];
1745     }
1746     /* Save data for creation of multiple bit streams */
1747     encData->pitchIndex[PITCH_SUBFRAMES * encData->startIdx + k] = index[k];
1748   }
1749 
1750   /* Un-quantize back to transform coefficients and do the inverse transform:
1751    * S = T'*C */
1752   C = (index[0] + lower_limit[0]) * StepSize;
1753   for (k = 0; k < PITCH_SUBFRAMES; k++) {
1754     PitchLags[k] = WebRtcIsac_kTransformTranspose[k][0] * C;
1755   }
1756   C = mean_val2[index[1]];
1757   for (k = 0; k < PITCH_SUBFRAMES; k++) {
1758     PitchLags[k] += WebRtcIsac_kTransformTranspose[k][1] * C;
1759   }
1760   C = mean_val3[index[2]];
1761   for (k = 0; k < PITCH_SUBFRAMES; k++) {
1762     PitchLags[k] += WebRtcIsac_kTransformTranspose[k][2] * C;
1763   }
1764   C = mean_val4[index[3]];
1765   for (k = 0; k < PITCH_SUBFRAMES; k++) {
1766     PitchLags[k] += WebRtcIsac_kTransformTranspose[k][3] * C;
1767   }
1768   /* entropy coding of quantization pitch lags */
1769   WebRtcIsac_EncHistMulti(streamdata, index, cdf, PITCH_SUBFRAMES);
1770 }
1771 
1772 
1773 
1774 /* Routines for in-band signaling of bandwidth estimation */
1775 /* Histograms based on uniform distribution of indices */
1776 /* Move global variables later! */
1777 
1778 
1779 /* cdf array for frame length indicator */
1780 const uint16_t WebRtcIsac_kFrameLengthCdf[4] = {
1781     0, 21845, 43690, 65535 };
1782 
1783 /* pointer to cdf array for frame length indicator */
1784 const uint16_t* WebRtcIsac_kFrameLengthCdf_ptr[1] = {
1785     WebRtcIsac_kFrameLengthCdf };
1786 
1787 /* initial cdf index for decoder of frame length indicator */
1788 const uint16_t WebRtcIsac_kFrameLengthInitIndex[1] = { 1 };
1789 
1790 
WebRtcIsac_DecodeFrameLen(Bitstr * streamdata,int16_t * framesamples)1791 int WebRtcIsac_DecodeFrameLen(Bitstr* streamdata, int16_t* framesamples) {
1792   int frame_mode, err;
1793   err = 0;
1794   /* entropy decoding of frame length [1:30ms,2:60ms] */
1795   err = WebRtcIsac_DecHistOneStepMulti(&frame_mode, streamdata,
1796                                        WebRtcIsac_kFrameLengthCdf_ptr,
1797                                        WebRtcIsac_kFrameLengthInitIndex, 1);
1798   if (err < 0)
1799     return -ISAC_RANGE_ERROR_DECODE_FRAME_LENGTH;
1800 
1801   switch (frame_mode) {
1802     case 1:
1803       *framesamples = 480; /* 30ms */
1804       break;
1805     case 2:
1806       *framesamples = 960; /* 60ms */
1807       break;
1808     default:
1809       err = -ISAC_DISALLOWED_FRAME_MODE_DECODER;
1810   }
1811   return err;
1812 }
1813 
WebRtcIsac_EncodeFrameLen(int16_t framesamples,Bitstr * streamdata)1814 int WebRtcIsac_EncodeFrameLen(int16_t framesamples, Bitstr* streamdata) {
1815   int frame_mode, status;
1816 
1817   status = 0;
1818   frame_mode = 0;
1819   /* entropy coding of frame length [1:480 samples,2:960 samples] */
1820   switch (framesamples) {
1821     case 480:
1822       frame_mode = 1;
1823       break;
1824     case 960:
1825       frame_mode = 2;
1826       break;
1827     default:
1828       status = - ISAC_DISALLOWED_FRAME_MODE_ENCODER;
1829   }
1830 
1831   if (status < 0)
1832     return status;
1833 
1834   WebRtcIsac_EncHistMulti(streamdata, &frame_mode,
1835                           WebRtcIsac_kFrameLengthCdf_ptr, 1);
1836   return status;
1837 }
1838 
1839 /* cdf array for estimated bandwidth */
1840 static const uint16_t kBwCdf[25] = {
1841     0, 2731, 5461, 8192, 10923, 13653, 16384, 19114, 21845, 24576, 27306, 30037,
1842     32768, 35498, 38229, 40959, 43690, 46421, 49151, 51882, 54613, 57343, 60074,
1843     62804, 65535 };
1844 
1845 /* pointer to cdf array for estimated bandwidth */
1846 static const uint16_t* const kBwCdfPtr[1] = { kBwCdf };
1847 
1848 /* initial cdf index for decoder of estimated bandwidth*/
1849 static const uint16_t kBwInitIndex[1] = { 7 };
1850 
1851 
WebRtcIsac_DecodeSendBW(Bitstr * streamdata,int16_t * BWno)1852 int WebRtcIsac_DecodeSendBW(Bitstr* streamdata, int16_t* BWno) {
1853   int BWno32, err;
1854 
1855   /* entropy decoding of sender's BW estimation [0..23] */
1856   err = WebRtcIsac_DecHistOneStepMulti(&BWno32, streamdata, kBwCdfPtr,
1857                                        kBwInitIndex, 1);
1858   if (err < 0) {
1859     return -ISAC_RANGE_ERROR_DECODE_BANDWIDTH;
1860   }
1861   *BWno = (int16_t)BWno32;
1862   return err;
1863 }
1864 
WebRtcIsac_EncodeReceiveBw(int * BWno,Bitstr * streamdata)1865 void WebRtcIsac_EncodeReceiveBw(int* BWno, Bitstr* streamdata) {
1866   /* entropy encoding of receiver's BW estimation [0..23] */
1867   WebRtcIsac_EncHistMulti(streamdata, BWno, kBwCdfPtr, 1);
1868 }
1869 
1870 
1871 /* estimate code length of LPC Coef */
WebRtcIsac_TranscodeLPCCoef(double * LPCCoef_lo,double * LPCCoef_hi,int * index_g)1872 void WebRtcIsac_TranscodeLPCCoef(double* LPCCoef_lo, double* LPCCoef_hi,
1873                                  int* index_g) {
1874   int j, k, n, pos, pos2, posg, offsg, offs2;
1875   int index_ovr_g[KLT_ORDER_GAIN];
1876   double tmpcoeffs_g[KLT_ORDER_GAIN];
1877   double tmpcoeffs2_g[KLT_ORDER_GAIN];
1878   double sum;
1879 
1880   /* log gains, mean removal and scaling */
1881   posg = 0;
1882   for (k = 0; k < SUBFRAMES; k++) {
1883     tmpcoeffs_g[posg] = log(LPCCoef_lo[(LPC_LOBAND_ORDER + 1) * k]);
1884     tmpcoeffs_g[posg] -= WebRtcIsac_kLpcMeansGain[posg];
1885     tmpcoeffs_g[posg] *= LPC_GAIN_SCALE;
1886     posg++;
1887     tmpcoeffs_g[posg] = log(LPCCoef_hi[(LPC_HIBAND_ORDER + 1) * k]);
1888     tmpcoeffs_g[posg] -= WebRtcIsac_kLpcMeansGain[posg];
1889     tmpcoeffs_g[posg] *= LPC_GAIN_SCALE;
1890     posg++;
1891   }
1892 
1893   /* KLT  */
1894 
1895   /* Left transform. */
1896   offsg = 0;
1897   for (j = 0; j < SUBFRAMES; j++) {
1898     posg = offsg;
1899     for (k = 0; k < LPC_GAIN_ORDER; k++) {
1900       sum = 0;
1901       pos = offsg;
1902       pos2 = k;
1903       for (n = 0; n < LPC_GAIN_ORDER; n++) {
1904         sum += tmpcoeffs_g[pos++] * WebRtcIsac_kKltT1Gain[pos2];
1905         pos2 += LPC_GAIN_ORDER;
1906       }
1907       tmpcoeffs2_g[posg++] = sum;
1908     }
1909     offsg += LPC_GAIN_ORDER;
1910   }
1911 
1912   /* Right transform. */
1913   offsg = 0;
1914   offs2 = 0;
1915   for (j = 0; j < SUBFRAMES; j++) {
1916     posg = offsg;
1917     for (k = 0; k < LPC_GAIN_ORDER; k++) {
1918       sum = 0;
1919       pos = k;
1920       pos2 = offs2;
1921       for (n = 0; n < SUBFRAMES; n++) {
1922         sum += tmpcoeffs2_g[pos] * WebRtcIsac_kKltT2Gain[pos2++];
1923         pos += LPC_GAIN_ORDER;
1924       }
1925       tmpcoeffs_g[posg++] = sum;
1926     }
1927     offs2 += SUBFRAMES;
1928     offsg += LPC_GAIN_ORDER;
1929   }
1930 
1931 
1932   /* quantize coefficients */
1933   for (k = 0; k < KLT_ORDER_GAIN; k++) {
1934     /* Get index. */
1935     pos2 = WebRtcIsac_lrint(tmpcoeffs_g[k] / KLT_STEPSIZE);
1936     index_g[k] = (pos2) + WebRtcIsac_kQKltQuantMinGain[k];
1937     if (index_g[k] < 0) {
1938       index_g[k] = 0;
1939     } else if (index_g[k] > WebRtcIsac_kQKltMaxIndGain[k]) {
1940       index_g[k] = WebRtcIsac_kQKltMaxIndGain[k];
1941     }
1942     index_ovr_g[k] = WebRtcIsac_kQKltOffsetGain[k] + index_g[k];
1943 
1944     /* find quantization levels for coefficients */
1945     tmpcoeffs_g[k] = WebRtcIsac_kQKltLevelsGain[index_ovr_g[k]];
1946   }
1947 }
1948 
1949 
1950 /* Decode & de-quantize LPC Coefficients. */
WebRtcIsac_DecodeLpcCoefUB(Bitstr * streamdata,double * lpcVecs,double * percepFilterGains,int16_t bandwidth)1951 int WebRtcIsac_DecodeLpcCoefUB(Bitstr* streamdata, double* lpcVecs,
1952                                double* percepFilterGains,
1953                                int16_t bandwidth) {
1954   int  index_s[KLT_ORDER_SHAPE];
1955 
1956   double U[UB_LPC_ORDER * UB16_LPC_VEC_PER_FRAME];
1957   int err;
1958 
1959   /* Entropy decoding of quantization indices. */
1960   switch (bandwidth) {
1961     case isac12kHz: {
1962       err = WebRtcIsac_DecHistOneStepMulti(
1963           index_s, streamdata, WebRtcIsac_kLpcShapeCdfMatUb12,
1964           WebRtcIsac_kLpcShapeEntropySearchUb12, UB_LPC_ORDER *
1965           UB_LPC_VEC_PER_FRAME);
1966       break;
1967     }
1968     case isac16kHz: {
1969       err = WebRtcIsac_DecHistOneStepMulti(
1970           index_s, streamdata, WebRtcIsac_kLpcShapeCdfMatUb16,
1971           WebRtcIsac_kLpcShapeEntropySearchUb16, UB_LPC_ORDER *
1972           UB16_LPC_VEC_PER_FRAME);
1973       break;
1974     }
1975     default:
1976       return -1;
1977   }
1978 
1979   if (err < 0) {
1980     return err;
1981   }
1982 
1983   WebRtcIsac_DequantizeLpcParam(index_s, lpcVecs, bandwidth);
1984   WebRtcIsac_CorrelateInterVec(lpcVecs, U, bandwidth);
1985   WebRtcIsac_CorrelateIntraVec(U, lpcVecs, bandwidth);
1986   WebRtcIsac_AddLarMean(lpcVecs, bandwidth);
1987   WebRtcIsac_DecodeLpcGainUb(percepFilterGains, streamdata);
1988 
1989   if (bandwidth == isac16kHz) {
1990     /* Decode another set of Gains. */
1991     WebRtcIsac_DecodeLpcGainUb(&percepFilterGains[SUBFRAMES], streamdata);
1992   }
1993   return 0;
1994 }
1995 
WebRtcIsac_EncodeBandwidth(enum ISACBandwidth bandwidth,Bitstr * streamData)1996 int16_t WebRtcIsac_EncodeBandwidth(enum ISACBandwidth bandwidth,
1997                                    Bitstr* streamData) {
1998   int bandwidthMode;
1999   switch (bandwidth) {
2000     case isac12kHz: {
2001       bandwidthMode = 0;
2002       break;
2003     }
2004     case isac16kHz: {
2005       bandwidthMode = 1;
2006       break;
2007     }
2008     default:
2009       return -ISAC_DISALLOWED_ENCODER_BANDWIDTH;
2010   }
2011   WebRtcIsac_EncHistMulti(streamData, &bandwidthMode, kOneBitEqualProbCdf_ptr,
2012                           1);
2013   return 0;
2014 }
2015 
WebRtcIsac_DecodeBandwidth(Bitstr * streamData,enum ISACBandwidth * bandwidth)2016 int16_t WebRtcIsac_DecodeBandwidth(Bitstr* streamData,
2017                                    enum ISACBandwidth* bandwidth) {
2018   int bandwidthMode;
2019   if (WebRtcIsac_DecHistOneStepMulti(&bandwidthMode, streamData,
2020                                      kOneBitEqualProbCdf_ptr,
2021                                      kOneBitEqualProbInitIndex, 1) < 0) {
2022     return -ISAC_RANGE_ERROR_DECODE_BANDWITH;
2023   }
2024   switch (bandwidthMode) {
2025     case 0: {
2026       *bandwidth = isac12kHz;
2027       break;
2028     }
2029     case 1: {
2030       *bandwidth = isac16kHz;
2031       break;
2032     }
2033     default:
2034       return -ISAC_DISALLOWED_BANDWIDTH_MODE_DECODER;
2035   }
2036   return 0;
2037 }
2038 
WebRtcIsac_EncodeJitterInfo(int32_t jitterIndex,Bitstr * streamData)2039 int16_t WebRtcIsac_EncodeJitterInfo(int32_t jitterIndex,
2040                                     Bitstr* streamData) {
2041   /* This is to avoid LINUX warning until we change 'int' to 'Word32'. */
2042   int intVar;
2043 
2044   if ((jitterIndex < 0) || (jitterIndex > 1)) {
2045     return -1;
2046   }
2047   intVar = (int)(jitterIndex);
2048   /* Use the same CDF table as for bandwidth
2049    * both take two values with equal probability.*/
2050   WebRtcIsac_EncHistMulti(streamData, &intVar, kOneBitEqualProbCdf_ptr, 1);
2051   return 0;
2052 }
2053 
WebRtcIsac_DecodeJitterInfo(Bitstr * streamData,int32_t * jitterInfo)2054 int16_t WebRtcIsac_DecodeJitterInfo(Bitstr* streamData,
2055                                     int32_t* jitterInfo) {
2056   int intVar;
2057   /* Use the same CDF table as for bandwidth
2058    * both take two values with equal probability. */
2059   if (WebRtcIsac_DecHistOneStepMulti(&intVar, streamData,
2060                                      kOneBitEqualProbCdf_ptr,
2061                                      kOneBitEqualProbInitIndex, 1) < 0) {
2062     return -ISAC_RANGE_ERROR_DECODE_BANDWITH;
2063   }
2064   *jitterInfo = (int16_t)(intVar);
2065   return 0;
2066 }
2067