1 /*
2 * Copyright (c) 2011 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
13 iLBC Speech Coder ANSI-C Source Code
14
15 WebRtcIlbcfix_CbSearch.c
16
17 ******************************************************************/
18
19 #include "defines.h"
20 #include "gain_quant.h"
21 #include "filtered_cb_vecs.h"
22 #include "constants.h"
23 #include "cb_mem_energy.h"
24 #include "interpolate_samples.h"
25 #include "cb_mem_energy_augmentation.h"
26 #include "cb_search_core.h"
27 #include "energy_inverse.h"
28 #include "augmented_cb_corr.h"
29 #include "cb_update_best_index.h"
30 #include "create_augmented_vec.h"
31
32 /*----------------------------------------------------------------*
33 * Search routine for codebook encoding and gain quantization.
34 *----------------------------------------------------------------*/
35
WebRtcIlbcfix_CbSearch(IlbcEncoder * iLBCenc_inst,int16_t * index,int16_t * gain_index,int16_t * intarget,int16_t * decResidual,size_t lMem,size_t lTarget,int16_t * weightDenum,size_t block)36 void WebRtcIlbcfix_CbSearch(
37 IlbcEncoder *iLBCenc_inst,
38 /* (i) the encoder state structure */
39 int16_t *index, /* (o) Codebook indices */
40 int16_t *gain_index, /* (o) Gain quantization indices */
41 int16_t *intarget, /* (i) Target vector for encoding */
42 int16_t *decResidual,/* (i) Decoded residual for codebook construction */
43 size_t lMem, /* (i) Length of buffer */
44 size_t lTarget, /* (i) Length of vector */
45 int16_t *weightDenum,/* (i) weighting filter coefficients in Q12 */
46 size_t block /* (i) the subblock number */
47 ) {
48 size_t i, range;
49 int16_t ii, j, stage;
50 int16_t *pp;
51 int16_t tmp;
52 int scale;
53 int16_t bits, temp1, temp2;
54 size_t base_size;
55 int32_t codedEner, targetEner;
56 int16_t gains[CB_NSTAGES+1];
57 int16_t *cb_vecPtr;
58 size_t indexOffset, sInd, eInd;
59 int32_t CritMax=0;
60 int16_t shTotMax=WEBRTC_SPL_WORD16_MIN;
61 size_t bestIndex=0;
62 int16_t bestGain=0;
63 size_t indexNew;
64 int16_t CritNewSh;
65 int32_t CritNew;
66 int32_t *cDotPtr;
67 size_t noOfZeros;
68 int16_t *gainPtr;
69 int32_t t32, tmpW32;
70 int16_t *WebRtcIlbcfix_kGainSq5_ptr;
71 /* Stack based */
72 int16_t CBbuf[CB_MEML+LPC_FILTERORDER+CB_HALFFILTERLEN];
73 int32_t cDot[128];
74 int32_t Crit[128];
75 int16_t targetVec[SUBL+LPC_FILTERORDER];
76 int16_t cbvectors[CB_MEML + 1]; /* Adding one extra position for
77 Coverity warnings. */
78 int16_t codedVec[SUBL];
79 int16_t interpSamples[20*4];
80 int16_t interpSamplesFilt[20*4];
81 int16_t energyW16[CB_EXPAND*128];
82 int16_t energyShifts[CB_EXPAND*128];
83 int16_t *inverseEnergy=energyW16; /* Reuse memory */
84 int16_t *inverseEnergyShifts=energyShifts; /* Reuse memory */
85 int16_t *buf = &CBbuf[LPC_FILTERORDER];
86 int16_t *target = &targetVec[LPC_FILTERORDER];
87 int16_t *aug_vec = (int16_t*)cDot; /* length [SUBL], reuse memory */
88
89 /* Determine size of codebook sections */
90
91 base_size=lMem-lTarget+1;
92 if (lTarget==SUBL) {
93 base_size=lMem-19;
94 }
95
96 /* weighting of the CB memory */
97 noOfZeros=lMem-WebRtcIlbcfix_kFilterRange[block];
98 WebRtcSpl_MemSetW16(&buf[-LPC_FILTERORDER], 0, noOfZeros+LPC_FILTERORDER);
99 WebRtcSpl_FilterARFastQ12(
100 decResidual+noOfZeros, buf+noOfZeros,
101 weightDenum, LPC_FILTERORDER+1, WebRtcIlbcfix_kFilterRange[block]);
102
103 /* weighting of the target vector */
104 WEBRTC_SPL_MEMCPY_W16(&target[-LPC_FILTERORDER], buf+noOfZeros+WebRtcIlbcfix_kFilterRange[block]-LPC_FILTERORDER, LPC_FILTERORDER);
105 WebRtcSpl_FilterARFastQ12(
106 intarget, target,
107 weightDenum, LPC_FILTERORDER+1, lTarget);
108
109 /* Store target, towards the end codedVec is calculated as
110 the initial target minus the remaining target */
111 WEBRTC_SPL_MEMCPY_W16(codedVec, target, lTarget);
112
113 /* Find the highest absolute value to calculate proper
114 vector scale factor (so that it uses 12 bits) */
115 temp1 = WebRtcSpl_MaxAbsValueW16(buf, lMem);
116 temp2 = WebRtcSpl_MaxAbsValueW16(target, lTarget);
117
118 if ((temp1>0)&&(temp2>0)) {
119 temp1 = WEBRTC_SPL_MAX(temp1, temp2);
120 scale = WebRtcSpl_GetSizeInBits((uint32_t)(temp1 * temp1));
121 } else {
122 /* temp1 or temp2 is negative (maximum was -32768) */
123 scale = 30;
124 }
125
126 /* Scale to so that a mul-add 40 times does not overflow */
127 scale = scale - 25;
128 scale = WEBRTC_SPL_MAX(0, scale);
129
130 /* Compute energy of the original target */
131 targetEner = WebRtcSpl_DotProductWithScale(target, target, lTarget, scale);
132
133 /* Prepare search over one more codebook section. This section
134 is created by filtering the original buffer with a filter. */
135 WebRtcIlbcfix_FilteredCbVecs(cbvectors, buf, lMem, WebRtcIlbcfix_kFilterRange[block]);
136
137 range = WebRtcIlbcfix_kSearchRange[block][0];
138
139 if(lTarget == SUBL) {
140 /* Create the interpolated samples and store them for use in all stages */
141
142 /* First section, non-filtered half of the cb */
143 WebRtcIlbcfix_InterpolateSamples(interpSamples, buf, lMem);
144
145 /* Second section, filtered half of the cb */
146 WebRtcIlbcfix_InterpolateSamples(interpSamplesFilt, cbvectors, lMem);
147
148 /* Compute the CB vectors' energies for the first cb section (non-filtered) */
149 WebRtcIlbcfix_CbMemEnergyAugmentation(interpSamples, buf,
150 scale, 20, energyW16, energyShifts);
151
152 /* Compute the CB vectors' energies for the second cb section (filtered cb) */
153 WebRtcIlbcfix_CbMemEnergyAugmentation(interpSamplesFilt, cbvectors, scale,
154 base_size + 20, energyW16,
155 energyShifts);
156
157 /* Compute the CB vectors' energies and store them in the vector
158 * energyW16. Also the corresponding shift values are stored. The
159 * energy values are used in all three stages. */
160 WebRtcIlbcfix_CbMemEnergy(range, buf, cbvectors, lMem,
161 lTarget, energyW16+20, energyShifts+20, scale, base_size);
162
163 } else {
164 /* Compute the CB vectors' energies and store them in the vector
165 * energyW16. Also the corresponding shift values are stored. The
166 * energy values are used in all three stages. */
167 WebRtcIlbcfix_CbMemEnergy(range, buf, cbvectors, lMem,
168 lTarget, energyW16, energyShifts, scale, base_size);
169
170 /* Set the energy positions 58-63 and 122-127 to zero
171 (otherwise they are uninitialized) */
172 WebRtcSpl_MemSetW16(energyW16+range, 0, (base_size-range));
173 WebRtcSpl_MemSetW16(energyW16+range+base_size, 0, (base_size-range));
174 }
175
176 /* Calculate Inverse Energy (energyW16 is already normalized
177 and will contain the inverse energy in Q29 after this call */
178 WebRtcIlbcfix_EnergyInverse(energyW16, base_size*CB_EXPAND);
179
180 /* The gain value computed in the previous stage is used
181 * as an upper limit to what the next stage gain value
182 * is allowed to be. In stage 0, 16384 (1.0 in Q14) is used as
183 * the upper limit. */
184 gains[0] = 16384;
185
186 for (stage=0; stage<CB_NSTAGES; stage++) {
187
188 /* Set up memories */
189 range = WebRtcIlbcfix_kSearchRange[block][stage];
190
191 /* initialize search measures */
192 CritMax=0;
193 shTotMax=-100;
194 bestIndex=0;
195 bestGain=0;
196
197 /* loop over lags 40+ in the first codebook section, full search */
198 cb_vecPtr = buf+lMem-lTarget;
199
200 /* Calculate all the cross correlations (augmented part of CB) */
201 if (lTarget==SUBL) {
202 WebRtcIlbcfix_AugmentedCbCorr(target, buf+lMem,
203 interpSamples, cDot,
204 20, 39, scale);
205 cDotPtr=&cDot[20];
206 } else {
207 cDotPtr=cDot;
208 }
209 /* Calculate all the cross correlations (main part of CB) */
210 WebRtcSpl_CrossCorrelation(cDotPtr, target, cb_vecPtr, lTarget, range, scale, -1);
211
212 /* Adjust the search range for the augmented vectors */
213 if (lTarget==SUBL) {
214 range=WebRtcIlbcfix_kSearchRange[block][stage]+20;
215 } else {
216 range=WebRtcIlbcfix_kSearchRange[block][stage];
217 }
218
219 indexOffset=0;
220
221 /* Search for best index in this part of the vector */
222 WebRtcIlbcfix_CbSearchCore(
223 cDot, range, stage, inverseEnergy,
224 inverseEnergyShifts, Crit,
225 &indexNew, &CritNew, &CritNewSh);
226
227 /* Update the global best index and the corresponding gain */
228 WebRtcIlbcfix_CbUpdateBestIndex(
229 CritNew, CritNewSh, indexNew+indexOffset, cDot[indexNew+indexOffset],
230 inverseEnergy[indexNew+indexOffset], inverseEnergyShifts[indexNew+indexOffset],
231 &CritMax, &shTotMax, &bestIndex, &bestGain);
232
233 sInd = ((CB_RESRANGE >> 1) > bestIndex) ?
234 0 : (bestIndex - (CB_RESRANGE >> 1));
235 eInd=sInd+CB_RESRANGE;
236 if (eInd>=range) {
237 eInd=range-1;
238 sInd=eInd-CB_RESRANGE;
239 }
240
241 range = WebRtcIlbcfix_kSearchRange[block][stage];
242
243 if (lTarget==SUBL) {
244 i=sInd;
245 if (sInd<20) {
246 WebRtcIlbcfix_AugmentedCbCorr(target, cbvectors + lMem,
247 interpSamplesFilt, cDot, sInd + 20,
248 WEBRTC_SPL_MIN(39, (eInd + 20)), scale);
249 i=20;
250 cDotPtr = &cDot[20 - sInd];
251 } else {
252 cDotPtr = cDot;
253 }
254
255 cb_vecPtr = cbvectors+lMem-20-i;
256
257 /* Calculate the cross correlations (main part of the filtered CB) */
258 WebRtcSpl_CrossCorrelation(cDotPtr, target, cb_vecPtr, lTarget,
259 eInd - i + 1, scale, -1);
260
261 } else {
262 cDotPtr = cDot;
263 cb_vecPtr = cbvectors+lMem-lTarget-sInd;
264
265 /* Calculate the cross correlations (main part of the filtered CB) */
266 WebRtcSpl_CrossCorrelation(cDotPtr, target, cb_vecPtr, lTarget,
267 eInd - sInd + 1, scale, -1);
268
269 }
270
271 /* Adjust the search range for the augmented vectors */
272 indexOffset=base_size+sInd;
273
274 /* Search for best index in this part of the vector */
275 WebRtcIlbcfix_CbSearchCore(
276 cDot, eInd-sInd+1, stage, inverseEnergy+indexOffset,
277 inverseEnergyShifts+indexOffset, Crit,
278 &indexNew, &CritNew, &CritNewSh);
279
280 /* Update the global best index and the corresponding gain */
281 WebRtcIlbcfix_CbUpdateBestIndex(
282 CritNew, CritNewSh, indexNew+indexOffset, cDot[indexNew],
283 inverseEnergy[indexNew+indexOffset], inverseEnergyShifts[indexNew+indexOffset],
284 &CritMax, &shTotMax, &bestIndex, &bestGain);
285
286 index[stage] = (int16_t)bestIndex;
287
288
289 bestGain = WebRtcIlbcfix_GainQuant(bestGain,
290 (int16_t)WEBRTC_SPL_ABS_W16(gains[stage]), stage, &gain_index[stage]);
291
292 /* Extract the best (according to measure) codebook vector
293 Also adjust the index, so that the augmented vectors are last.
294 Above these vectors were first...
295 */
296
297 if(lTarget==(STATE_LEN-iLBCenc_inst->state_short_len)) {
298
299 if((size_t)index[stage]<base_size) {
300 pp=buf+lMem-lTarget-index[stage];
301 } else {
302 pp=cbvectors+lMem-lTarget-
303 index[stage]+base_size;
304 }
305
306 } else {
307
308 if ((size_t)index[stage]<base_size) {
309 if (index[stage]>=20) {
310 /* Adjust index and extract vector */
311 index[stage]-=20;
312 pp=buf+lMem-lTarget-index[stage];
313 } else {
314 /* Adjust index and extract vector */
315 index[stage]+=(int16_t)(base_size-20);
316
317 WebRtcIlbcfix_CreateAugmentedVec(index[stage]-base_size+40,
318 buf+lMem, aug_vec);
319 pp = aug_vec;
320
321 }
322 } else {
323
324 if ((index[stage] - base_size) >= 20) {
325 /* Adjust index and extract vector */
326 index[stage]-=20;
327 pp=cbvectors+lMem-lTarget-
328 index[stage]+base_size;
329 } else {
330 /* Adjust index and extract vector */
331 index[stage]+=(int16_t)(base_size-20);
332 WebRtcIlbcfix_CreateAugmentedVec(index[stage]-2*base_size+40,
333 cbvectors+lMem, aug_vec);
334 pp = aug_vec;
335 }
336 }
337 }
338
339 /* Subtract the best codebook vector, according
340 to measure, from the target vector */
341
342 WebRtcSpl_AddAffineVectorToVector(target, pp, (int16_t)(-bestGain),
343 (int32_t)8192, (int16_t)14, lTarget);
344
345 /* record quantized gain */
346 gains[stage+1] = bestGain;
347
348 } /* end of Main Loop. for (stage=0;... */
349
350 /* Calculte the coded vector (original target - what's left) */
351 for (i=0;i<lTarget;i++) {
352 codedVec[i]-=target[i];
353 }
354
355 /* Gain adjustment for energy matching */
356 codedEner = WebRtcSpl_DotProductWithScale(codedVec, codedVec, lTarget, scale);
357
358 j=gain_index[0];
359
360 temp1 = (int16_t)WebRtcSpl_NormW32(codedEner);
361 temp2 = (int16_t)WebRtcSpl_NormW32(targetEner);
362
363 if(temp1 < temp2) {
364 bits = 16 - temp1;
365 } else {
366 bits = 16 - temp2;
367 }
368
369 tmp = (int16_t)((gains[1] * gains[1]) >> 14);
370
371 targetEner = (int16_t)WEBRTC_SPL_SHIFT_W32(targetEner, -bits) * tmp;
372
373 tmpW32 = ((int32_t)(gains[1]-1))<<1;
374
375 /* Pointer to the table that contains
376 gain_sq5TblFIX * gain_sq5TblFIX in Q14 */
377 gainPtr=(int16_t*)WebRtcIlbcfix_kGainSq5Sq+gain_index[0];
378 temp1 = (int16_t)WEBRTC_SPL_SHIFT_W32(codedEner, -bits);
379
380 WebRtcIlbcfix_kGainSq5_ptr = (int16_t*)&WebRtcIlbcfix_kGainSq5[j];
381
382 /* targetEner and codedEner are in Q(-2*scale) */
383 for (ii=gain_index[0];ii<32;ii++) {
384
385 /* Change the index if
386 (codedEnergy*gainTbl[i]*gainTbl[i])<(targetEn*gain[0]*gain[0]) AND
387 gainTbl[i] < 2*gain[0]
388 */
389
390 t32 = temp1 * *gainPtr;
391 t32 = t32 - targetEner;
392 if (t32 < 0) {
393 if ((*WebRtcIlbcfix_kGainSq5_ptr) < tmpW32) {
394 j=ii;
395 WebRtcIlbcfix_kGainSq5_ptr = (int16_t*)&WebRtcIlbcfix_kGainSq5[ii];
396 }
397 }
398 gainPtr++;
399 }
400 gain_index[0]=j;
401
402 return;
403 }
404