Roman Khassraf | d38206c | 2015-06-07 16:26:29 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2013, 2014 Range Networks, Inc. |
| 3 | * |
| 4 | * This software is distributed under multiple licenses; |
| 5 | * see the COPYING file in the main directory for licensing |
| 6 | * information for this specific distribution. |
| 7 | * |
| 8 | * This use of this software may be subject to additional restrictions. |
| 9 | * See the LEGAL file in the main directory for details. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 14 | |
| 15 | */ |
| 16 | |
| 17 | |
| 18 | #include "BitVector.h" |
| 19 | #include "AmrCoder.h" |
| 20 | #include <iostream> |
| 21 | #include <stdio.h> |
| 22 | #include <sstream> |
| 23 | |
| 24 | using namespace std; |
| 25 | |
| 26 | |
| 27 | |
| 28 | ViterbiTCH_AFS12_2::ViterbiTCH_AFS12_2() |
| 29 | { |
| 30 | assert(mDeferral < 32); |
| 31 | mCoeffs[0] = 0x019; |
| 32 | mCoeffsFB[0] = 0x019; |
| 33 | mCoeffs[1] = 0x01b; |
| 34 | mCoeffsFB[1] = 0x019; |
| 35 | for (unsigned i = 0; i < mIRate; i++) { |
| 36 | computeStateTables(i); |
| 37 | } |
| 38 | computeGeneratorTable(); |
| 39 | } |
| 40 | |
| 41 | |
| 42 | //void BitVector::encode(const ViterbiTCH_AFS12_2& coder, BitVector& target) const |
| 43 | void ViterbiTCH_AFS12_2::encode(const BitVector& in, BitVector& target) const |
| 44 | { |
| 45 | assert(in.size() == 250); |
| 46 | assert(target.size() == 508); |
| 47 | const char *u = in.begin(); |
| 48 | char *C = target.begin(); |
| 49 | const unsigned H = 4; |
| 50 | BitVector r(254+H); |
| 51 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 52 | for (unsigned k = 0; k <= 249; k++) { |
| 53 | r[k+H] = u[k] ^ r[k-3+H] ^ r[k-4+H]; |
| 54 | C[2*k] = u[k]; |
| 55 | C[2*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 56 | } |
| 57 | // termination |
| 58 | for (unsigned k = 250; k <= 253; k++) { |
| 59 | r[k+H] = 0; |
| 60 | C[2*k] = r[k-3+H] ^ r[k-4+H]; |
| 61 | C[2*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | |
| 66 | |
| 67 | //void BitVector::encode(const ViterbiTCH_AFS10_2& coder, BitVector& target) |
| 68 | void ViterbiTCH_AFS10_2::encode(const BitVector& in, BitVector& target) const |
| 69 | { |
| 70 | assert(in.size() == 210); |
| 71 | assert(target.size() == 642); |
| 72 | const char *u = in.begin(); |
| 73 | char *C = target.begin(); |
| 74 | const unsigned H = 4; |
| 75 | BitVector r(214+H); |
| 76 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 77 | for (unsigned k = 0; k <= 209; k++) { |
| 78 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 79 | C[3*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 80 | C[3*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 81 | C[3*k+2] = u[k]; |
| 82 | } |
| 83 | // termination |
| 84 | for (unsigned k = 210; k <= 213; k++) { |
| 85 | r[k+H] = 0; |
| 86 | C[3*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 87 | C[3*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 88 | C[3*k+2] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | |
| 93 | |
| 94 | //void BitVector::encode(const ViterbiTCH_AFS7_95& coder, BitVector& target) |
| 95 | void ViterbiTCH_AFS7_95::encode(const BitVector& in, BitVector& target) const |
| 96 | { |
| 97 | assert(in.size() == 165); |
| 98 | assert(target.size() == 513); |
| 99 | const char *u = in.begin(); |
| 100 | char *C = target.begin(); |
| 101 | const unsigned H = 6; |
| 102 | BitVector r(171+H); |
| 103 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 104 | for (unsigned k = 0; k <= 164; k++) { |
| 105 | r[k+H] = u[k] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 106 | C[3*k] = u[k]; |
| 107 | C[3*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 108 | C[3*k+2] = r[k+H] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 109 | } |
| 110 | // termination |
| 111 | for (unsigned k = 165; k <= 170; k++) { |
| 112 | r[k+H] = 0; |
| 113 | C[3*k] = r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 114 | C[3*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 115 | C[3*k+2] = r[k+H] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | |
| 120 | |
| 121 | void ViterbiTCH_AFS7_4::encode(const BitVector& in, BitVector& target) const |
| 122 | { |
| 123 | assert(in.size() == 154); |
| 124 | assert(target.size() == 474); |
| 125 | const char *u = in.begin(); |
| 126 | char *C = target.begin(); |
| 127 | const unsigned H = 4; |
| 128 | BitVector r(158+H); |
| 129 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 130 | for (unsigned k = 0; k <= 153; k++) { |
| 131 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 132 | C[3*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 133 | C[3*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 134 | C[3*k+2] = u[k]; |
| 135 | } |
| 136 | // termination |
| 137 | for (unsigned k = 154; k <= 157; k++) { |
| 138 | r[k+H] = 0; |
| 139 | C[3*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 140 | C[3*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 141 | C[3*k+2] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | |
| 146 | |
| 147 | void ViterbiTCH_AFS6_7::encode(const BitVector& in, BitVector& target) const |
| 148 | { |
| 149 | assert(in.size() == 140); |
| 150 | assert(target.size() == 576); |
| 151 | const char *u = in.begin(); |
| 152 | char *C = target.begin(); |
| 153 | const unsigned H = 4; |
| 154 | BitVector r(144+H); |
| 155 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 156 | for (unsigned k = 0; k <= 139; k++) { |
| 157 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 158 | C[4*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 159 | C[4*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 160 | C[4*k+2] = u[k]; |
| 161 | C[4*k+3] = u[k]; |
| 162 | } |
| 163 | // termination |
| 164 | for (unsigned k = 140; k <= 143; k++) { |
| 165 | r[k+H] = 0; |
| 166 | C[4*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 167 | C[4*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 168 | C[4*k+2] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 169 | C[4*k+3] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | |
| 174 | |
| 175 | void ViterbiTCH_AFS5_9::encode(const BitVector& in, BitVector& target) const |
| 176 | { |
| 177 | assert(in.size() == 124); |
| 178 | assert(target.size() == 520); |
| 179 | const char *u = in.begin(); |
| 180 | char *C = target.begin(); |
| 181 | const unsigned H = 6; |
| 182 | BitVector r(130+H); |
| 183 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 184 | for (unsigned k = 0; k <= 123; k++) { |
| 185 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 186 | C[4*k] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 187 | C[4*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 188 | C[4*k+2] = u[k]; |
| 189 | C[4*k+3] = u[k]; |
| 190 | } |
| 191 | // termination |
| 192 | for (unsigned k = 124; k <= 129; k++) { |
| 193 | r[k+H] = 0; |
| 194 | C[4*k] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 195 | C[4*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 196 | C[4*k+2] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 197 | C[4*k+3] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | |
| 202 | |
| 203 | void ViterbiTCH_AFS5_15::encode(const BitVector& in, BitVector& target) const |
| 204 | { |
| 205 | assert(in.size() == 109); |
| 206 | assert(target.size() == 565); |
| 207 | const char *u = in.begin(); |
| 208 | char *C = target.begin(); |
| 209 | const unsigned H = 4; |
| 210 | BitVector r(113+H); |
| 211 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 212 | for (unsigned k = 0; k <= 108; k++) { |
| 213 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 214 | C[5*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 215 | C[5*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 216 | C[5*k+2] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 217 | C[5*k+3] = u[k]; |
| 218 | C[5*k+4] = u[k]; |
| 219 | } |
| 220 | // termination |
| 221 | for (unsigned k = 109; k <= 112; k++) { |
| 222 | r[k+H] = 0; |
| 223 | C[5*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 224 | C[5*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 225 | C[5*k+2] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 226 | C[5*k+3] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 227 | C[5*k+4] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | |
| 232 | |
| 233 | void ViterbiTCH_AFS4_75::encode(const BitVector& in, BitVector& target) const |
| 234 | { |
| 235 | assert(in.size() == 101); |
| 236 | assert(target.size() == 535); |
| 237 | const char *u = in.begin(); |
| 238 | char *C = target.begin(); |
| 239 | const unsigned H = 6; |
| 240 | BitVector r(107+H); |
| 241 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 242 | for (unsigned k = 0; k <= 100; k++) { |
| 243 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 244 | C[5*k] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 245 | C[5*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 246 | C[5*k+2] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 247 | C[5*k+3] = u[k]; |
| 248 | C[5*k+4] = u[k]; |
| 249 | } |
| 250 | // termination |
| 251 | for (unsigned k = 101; k <= 106; k++) { |
| 252 | r[k+H] = 0; |
| 253 | C[5*k] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 254 | C[5*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 255 | C[5*k+2] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 256 | C[5*k+3] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 257 | C[5*k+4] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 258 | } |
| 259 | } |
| 260 | |
| 261 | |
| 262 | void ViterbiTCH_AFS12_2::initializeStates() |
| 263 | { |
| 264 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 265 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 266 | } |
| 267 | |
| 268 | |
| 269 | |
| 270 | void ViterbiTCH_AFS12_2::computeStateTables(unsigned g) |
| 271 | { |
| 272 | assert(g<mIRate); |
| 273 | for (unsigned state=0; state<mIStates; state++) { |
| 274 | for (unsigned in = 0; in <= 1; in++) { |
| 275 | uint32_t inputVal = (state<<1) | in; |
| 276 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 277 | } |
| 278 | } |
| 279 | } |
| 280 | |
| 281 | void ViterbiTCH_AFS12_2::computeGeneratorTable() |
| 282 | { |
| 283 | for (unsigned index=0; index<mIStates*2; index++) { |
| 284 | uint32_t t = 0; |
| 285 | for (unsigned i = 0; i < mIRate; i++) { |
| 286 | t = (t << 1) | mStateTable[i][index]; |
| 287 | } |
| 288 | mGeneratorTable[index] = t; |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | |
| 293 | |
| 294 | |
| 295 | |
| 296 | |
| 297 | void ViterbiTCH_AFS12_2::branchCandidates() |
| 298 | { |
| 299 | // Branch to generate new input states. |
| 300 | const vCand *sp = mSurvivors; |
| 301 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 302 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 303 | for (unsigned in = 0; in <= 1; in++) { |
| 304 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 305 | mCandidates[cand+in].cost = sp->cost; |
| 306 | uint32_t outputs = oStateShifted; |
| 307 | for (unsigned out = 0; out < mIRate; out++) { |
| 308 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 309 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 310 | mCandidates[cand+in].rState[out] = rState; |
| 311 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 312 | } |
| 313 | mCandidates[cand+in].oState = outputs; |
| 314 | } |
| 315 | sp++; |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | |
| 320 | void ViterbiTCH_AFS12_2::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 321 | { |
| 322 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 323 | for (unsigned i=0; i<mNumCands; i++) { |
| 324 | vCand& thisCand = mCandidates[i]; |
| 325 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 326 | for (unsigned i = 0; i < mIRate; i++) { |
| 327 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 328 | } |
| 329 | } |
| 330 | } |
| 331 | |
| 332 | |
| 333 | void ViterbiTCH_AFS12_2::pruneCandidates() |
| 334 | { |
| 335 | const vCand* c1 = mCandidates; // 0-prefix |
| 336 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 337 | for (unsigned i=0; i<mIStates; i++) { |
| 338 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 339 | else mSurvivors[i] = c2[i]; |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | |
| 344 | const ViterbiTCH_AFS12_2::vCand& ViterbiTCH_AFS12_2::minCost() const |
| 345 | { |
| 346 | int minIndex = 0; |
| 347 | float minCost = mSurvivors[0].cost; |
| 348 | for (unsigned i=1; i<mIStates; i++) { |
| 349 | const float thisCost = mSurvivors[i].cost; |
| 350 | if (thisCost>=minCost) continue; |
| 351 | minCost = thisCost; |
| 352 | minIndex=i; |
| 353 | } |
| 354 | return mSurvivors[minIndex]; |
| 355 | } |
| 356 | |
| 357 | |
| 358 | const ViterbiTCH_AFS12_2::vCand& ViterbiTCH_AFS12_2::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 359 | { |
| 360 | branchCandidates(); |
| 361 | getSoftCostMetrics(inSample,probs,iprobs); |
| 362 | pruneCandidates(); |
| 363 | return minCost(); |
| 364 | } |
| 365 | |
| 366 | |
| 367 | |
| 368 | void ViterbiTCH_AFS12_2::decode(const SoftVector &in, BitVector& target) |
| 369 | { |
| 370 | ViterbiTCH_AFS12_2 &decoder = *this; |
| 371 | const size_t sz = in.size() - 8; |
| 372 | const unsigned deferral = decoder.deferral(); |
| 373 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 374 | assert(sz == decoder.iRate()*target.size()); |
| 375 | |
| 376 | // Build a "history" array where each element contains the full history. |
| 377 | uint32_t history[ctsz]; |
| 378 | { |
| 379 | BitVector bits = in.sliced(); |
| 380 | uint32_t accum = 0; |
| 381 | for (size_t i=0; i<sz; i++) { |
| 382 | accum = (accum<<1) | bits.bit(i); |
| 383 | history[i] = accum; |
| 384 | } |
| 385 | // Repeat last bit at the end. |
| 386 | for (size_t i=sz; i<ctsz; i++) { |
| 387 | accum = (accum<<1) | (accum & 0x01); |
| 388 | history[i] = accum; |
| 389 | } |
| 390 | } |
| 391 | |
| 392 | // Precompute metric tables. |
| 393 | float matchCostTable[ctsz]; |
| 394 | float mismatchCostTable[ctsz]; |
| 395 | { |
| 396 | const float *dp = in.begin(); |
| 397 | for (size_t i=0; i<sz; i++) { |
| 398 | // pVal is the probability that a bit is correct. |
| 399 | // ipVal is the probability that a bit is incorrect. |
| 400 | float pVal = dp[i]; |
| 401 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 402 | float ipVal = 1.0F-pVal; |
| 403 | // This is a cheap approximation to an ideal cost function. |
| 404 | if (pVal<0.01F) pVal = 0.01; |
| 405 | if (ipVal<0.01F) ipVal = 0.01; |
| 406 | matchCostTable[i] = 0.25F/ipVal; |
| 407 | mismatchCostTable[i] = 0.25F/pVal; |
| 408 | } |
| 409 | |
| 410 | // pad end of table with unknowns |
| 411 | for (size_t i=sz; i<ctsz; i++) { |
| 412 | matchCostTable[i] = 0.5F; |
| 413 | mismatchCostTable[i] = 0.5F; |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | { |
| 418 | decoder.initializeStates(); |
| 419 | // Each sample of history[] carries its history. |
| 420 | // So we only have to process every iRate-th sample. |
| 421 | const unsigned step = decoder.iRate(); |
| 422 | // input pointer |
| 423 | const uint32_t *ip = history + step - 1; |
| 424 | // output pointers |
| 425 | char *op = target.begin(); |
| 426 | const char *const opt = target.end(); |
| 427 | // table pointers |
| 428 | const float* match = matchCostTable; |
| 429 | const float* mismatch = mismatchCostTable; |
| 430 | size_t oCount = 0; |
| 431 | while (op<opt) { |
| 432 | // Viterbi algorithm |
| 433 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 434 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 435 | const ViterbiTCH_AFS12_2::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 436 | ip += step; |
| 437 | match += step; |
| 438 | mismatch += step; |
| 439 | // output |
| 440 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 441 | oCount++; |
| 442 | } |
| 443 | } |
| 444 | } |
| 445 | |
| 446 | |
| 447 | |
| 448 | ViterbiTCH_AFS10_2::ViterbiTCH_AFS10_2() |
| 449 | { |
| 450 | assert(mDeferral < 32); |
| 451 | mCoeffs[0] = 0x01b; |
| 452 | mCoeffsFB[0] = 0x01f; |
| 453 | mCoeffs[1] = 0x015; |
| 454 | mCoeffsFB[1] = 0x01f; |
| 455 | mCoeffs[2] = 0x01f; |
| 456 | mCoeffsFB[2] = 0x01f; |
| 457 | for (unsigned i = 0; i < mIRate; i++) { |
| 458 | computeStateTables(i); |
| 459 | } |
| 460 | computeGeneratorTable(); |
| 461 | } |
| 462 | |
| 463 | |
| 464 | |
| 465 | |
| 466 | void ViterbiTCH_AFS10_2::initializeStates() |
| 467 | { |
| 468 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 469 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 470 | } |
| 471 | |
| 472 | |
| 473 | |
| 474 | void ViterbiTCH_AFS10_2::computeStateTables(unsigned g) |
| 475 | { |
| 476 | assert(g<mIRate); |
| 477 | for (unsigned state=0; state<mIStates; state++) { |
| 478 | for (unsigned in = 0; in <= 1; in++) { |
| 479 | uint32_t inputVal = (state<<1) | in; |
| 480 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 481 | } |
| 482 | } |
| 483 | } |
| 484 | |
| 485 | void ViterbiTCH_AFS10_2::computeGeneratorTable() |
| 486 | { |
| 487 | for (unsigned index=0; index<mIStates*2; index++) { |
| 488 | uint32_t t = 0; |
| 489 | for (unsigned i = 0; i < mIRate; i++) { |
| 490 | t = (t << 1) | mStateTable[i][index]; |
| 491 | } |
| 492 | mGeneratorTable[index] = t; |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | |
| 497 | |
| 498 | |
| 499 | |
| 500 | |
| 501 | void ViterbiTCH_AFS10_2::branchCandidates() |
| 502 | { |
| 503 | // Branch to generate new input states. |
| 504 | const vCand *sp = mSurvivors; |
| 505 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 506 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 507 | for (unsigned in = 0; in <= 1; in++) { |
| 508 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 509 | mCandidates[cand+in].cost = sp->cost; |
| 510 | uint32_t outputs = oStateShifted; |
| 511 | for (unsigned out = 0; out < mIRate; out++) { |
| 512 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 513 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 514 | mCandidates[cand+in].rState[out] = rState; |
| 515 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 516 | } |
| 517 | mCandidates[cand+in].oState = outputs; |
| 518 | } |
| 519 | sp++; |
| 520 | } |
| 521 | } |
| 522 | |
| 523 | |
| 524 | void ViterbiTCH_AFS10_2::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 525 | { |
| 526 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 527 | for (unsigned i=0; i<mNumCands; i++) { |
| 528 | vCand& thisCand = mCandidates[i]; |
| 529 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 530 | for (unsigned i = 0; i < mIRate; i++) { |
| 531 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 532 | } |
| 533 | } |
| 534 | } |
| 535 | |
| 536 | |
| 537 | void ViterbiTCH_AFS10_2::pruneCandidates() |
| 538 | { |
| 539 | const vCand* c1 = mCandidates; // 0-prefix |
| 540 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 541 | for (unsigned i=0; i<mIStates; i++) { |
| 542 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 543 | else mSurvivors[i] = c2[i]; |
| 544 | } |
| 545 | } |
| 546 | |
| 547 | |
| 548 | const ViterbiTCH_AFS10_2::vCand& ViterbiTCH_AFS10_2::minCost() const |
| 549 | { |
| 550 | int minIndex = 0; |
| 551 | float minCost = mSurvivors[0].cost; |
| 552 | for (unsigned i=1; i<mIStates; i++) { |
| 553 | const float thisCost = mSurvivors[i].cost; |
| 554 | if (thisCost>=minCost) continue; |
| 555 | minCost = thisCost; |
| 556 | minIndex=i; |
| 557 | } |
| 558 | return mSurvivors[minIndex]; |
| 559 | } |
| 560 | |
| 561 | |
| 562 | const ViterbiTCH_AFS10_2::vCand& ViterbiTCH_AFS10_2::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 563 | { |
| 564 | branchCandidates(); |
| 565 | getSoftCostMetrics(inSample,probs,iprobs); |
| 566 | pruneCandidates(); |
| 567 | return minCost(); |
| 568 | } |
| 569 | |
| 570 | |
| 571 | |
| 572 | void ViterbiTCH_AFS10_2::decode(const SoftVector &in, BitVector& target) |
| 573 | { |
| 574 | ViterbiTCH_AFS10_2 &decoder = *this; |
| 575 | const size_t sz = in.size() - 12; |
| 576 | const unsigned deferral = decoder.deferral(); |
| 577 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 578 | assert(sz == decoder.iRate()*target.size()); |
| 579 | |
| 580 | // Build a "history" array where each element contains the full history. |
| 581 | uint32_t history[ctsz]; |
| 582 | { |
| 583 | BitVector bits = in.sliced(); |
| 584 | uint32_t accum = 0; |
| 585 | for (size_t i=0; i<sz; i++) { |
| 586 | accum = (accum<<1) | bits.bit(i); |
| 587 | history[i] = accum; |
| 588 | } |
| 589 | // Repeat last bit at the end. |
| 590 | for (size_t i=sz; i<ctsz; i++) { |
| 591 | accum = (accum<<1) | (accum & 0x01); |
| 592 | history[i] = accum; |
| 593 | } |
| 594 | } |
| 595 | |
| 596 | // Precompute metric tables. |
| 597 | float matchCostTable[ctsz]; |
| 598 | float mismatchCostTable[ctsz]; |
| 599 | { |
| 600 | const float *dp = in.begin(); |
| 601 | for (size_t i=0; i<sz; i++) { |
| 602 | // pVal is the probability that a bit is correct. |
| 603 | // ipVal is the probability that a bit is incorrect. |
| 604 | float pVal = dp[i]; |
| 605 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 606 | float ipVal = 1.0F-pVal; |
| 607 | // This is a cheap approximation to an ideal cost function. |
| 608 | if (pVal<0.01F) pVal = 0.01; |
| 609 | if (ipVal<0.01F) ipVal = 0.01; |
| 610 | matchCostTable[i] = 0.25F/ipVal; |
| 611 | mismatchCostTable[i] = 0.25F/pVal; |
| 612 | } |
| 613 | |
| 614 | // pad end of table with unknowns |
| 615 | for (size_t i=sz; i<ctsz; i++) { |
| 616 | matchCostTable[i] = 0.5F; |
| 617 | mismatchCostTable[i] = 0.5F; |
| 618 | } |
| 619 | } |
| 620 | |
| 621 | { |
| 622 | decoder.initializeStates(); |
| 623 | // Each sample of history[] carries its history. |
| 624 | // So we only have to process every iRate-th sample. |
| 625 | const unsigned step = decoder.iRate(); |
| 626 | // input pointer |
| 627 | const uint32_t *ip = history + step - 1; |
| 628 | // output pointers |
| 629 | char *op = target.begin(); |
| 630 | const char *const opt = target.end(); |
| 631 | // table pointers |
| 632 | const float* match = matchCostTable; |
| 633 | const float* mismatch = mismatchCostTable; |
| 634 | size_t oCount = 0; |
| 635 | while (op<opt) { |
| 636 | // Viterbi algorithm |
| 637 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 638 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 639 | const ViterbiTCH_AFS10_2::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 640 | ip += step; |
| 641 | match += step; |
| 642 | mismatch += step; |
| 643 | // output |
| 644 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 645 | oCount++; |
| 646 | } |
| 647 | } |
| 648 | } |
| 649 | |
| 650 | |
| 651 | |
| 652 | ViterbiTCH_AFS7_95::ViterbiTCH_AFS7_95() |
| 653 | { |
| 654 | assert(mDeferral < 32); |
| 655 | mCoeffs[0] = 0x06d; |
| 656 | mCoeffsFB[0] = 0x06d; |
| 657 | mCoeffs[1] = 0x053; |
| 658 | mCoeffsFB[1] = 0x06d; |
| 659 | mCoeffs[2] = 0x05f; |
| 660 | mCoeffsFB[2] = 0x06d; |
| 661 | for (unsigned i = 0; i < mIRate; i++) { |
| 662 | computeStateTables(i); |
| 663 | } |
| 664 | computeGeneratorTable(); |
| 665 | } |
| 666 | |
| 667 | |
| 668 | |
| 669 | |
| 670 | void ViterbiTCH_AFS7_95::initializeStates() |
| 671 | { |
| 672 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 673 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 674 | } |
| 675 | |
| 676 | |
| 677 | |
| 678 | void ViterbiTCH_AFS7_95::computeStateTables(unsigned g) |
| 679 | { |
| 680 | assert(g<mIRate); |
| 681 | for (unsigned state=0; state<mIStates; state++) { |
| 682 | for (unsigned in = 0; in <= 1; in++) { |
| 683 | uint32_t inputVal = (state<<1) | in; |
| 684 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 685 | } |
| 686 | } |
| 687 | } |
| 688 | |
| 689 | void ViterbiTCH_AFS7_95::computeGeneratorTable() |
| 690 | { |
| 691 | for (unsigned index=0; index<mIStates*2; index++) { |
| 692 | uint32_t t = 0; |
| 693 | for (unsigned i = 0; i < mIRate; i++) { |
| 694 | t = (t << 1) | mStateTable[i][index]; |
| 695 | } |
| 696 | mGeneratorTable[index] = t; |
| 697 | } |
| 698 | } |
| 699 | |
| 700 | |
| 701 | |
| 702 | |
| 703 | |
| 704 | |
| 705 | void ViterbiTCH_AFS7_95::branchCandidates() |
| 706 | { |
| 707 | // Branch to generate new input states. |
| 708 | const vCand *sp = mSurvivors; |
| 709 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 710 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 711 | for (unsigned in = 0; in <= 1; in++) { |
| 712 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 713 | mCandidates[cand+in].cost = sp->cost; |
| 714 | uint32_t outputs = oStateShifted; |
| 715 | for (unsigned out = 0; out < mIRate; out++) { |
| 716 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 717 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 718 | mCandidates[cand+in].rState[out] = rState; |
| 719 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 720 | } |
| 721 | mCandidates[cand+in].oState = outputs; |
| 722 | } |
| 723 | sp++; |
| 724 | } |
| 725 | } |
| 726 | |
| 727 | |
| 728 | void ViterbiTCH_AFS7_95::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 729 | { |
| 730 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 731 | for (unsigned i=0; i<mNumCands; i++) { |
| 732 | vCand& thisCand = mCandidates[i]; |
| 733 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 734 | for (unsigned i = 0; i < mIRate; i++) { |
| 735 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 736 | } |
| 737 | } |
| 738 | } |
| 739 | |
| 740 | |
| 741 | void ViterbiTCH_AFS7_95::pruneCandidates() |
| 742 | { |
| 743 | const vCand* c1 = mCandidates; // 0-prefix |
| 744 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 745 | for (unsigned i=0; i<mIStates; i++) { |
| 746 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 747 | else mSurvivors[i] = c2[i]; |
| 748 | } |
| 749 | } |
| 750 | |
| 751 | |
| 752 | const ViterbiTCH_AFS7_95::vCand& ViterbiTCH_AFS7_95::minCost() const |
| 753 | { |
| 754 | int minIndex = 0; |
| 755 | float minCost = mSurvivors[0].cost; |
| 756 | for (unsigned i=1; i<mIStates; i++) { |
| 757 | const float thisCost = mSurvivors[i].cost; |
| 758 | if (thisCost>=minCost) continue; |
| 759 | minCost = thisCost; |
| 760 | minIndex=i; |
| 761 | } |
| 762 | return mSurvivors[minIndex]; |
| 763 | } |
| 764 | |
| 765 | |
| 766 | const ViterbiTCH_AFS7_95::vCand& ViterbiTCH_AFS7_95::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 767 | { |
| 768 | branchCandidates(); |
| 769 | getSoftCostMetrics(inSample,probs,iprobs); |
| 770 | pruneCandidates(); |
| 771 | return minCost(); |
| 772 | } |
| 773 | |
| 774 | |
| 775 | |
| 776 | void ViterbiTCH_AFS7_95::decode(const SoftVector &in, BitVector& target) |
| 777 | { |
| 778 | ViterbiTCH_AFS7_95 &decoder = *this; |
| 779 | const size_t sz = in.size() - 18; |
| 780 | const unsigned deferral = decoder.deferral(); |
| 781 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 782 | assert(sz == decoder.iRate()*target.size()); |
| 783 | |
| 784 | // Build a "history" array where each element contains the full history. |
| 785 | uint32_t history[ctsz]; |
| 786 | { |
| 787 | BitVector bits = in.sliced(); |
| 788 | uint32_t accum = 0; |
| 789 | for (size_t i=0; i<sz; i++) { |
| 790 | accum = (accum<<1) | bits.bit(i); |
| 791 | history[i] = accum; |
| 792 | } |
| 793 | // Repeat last bit at the end. |
| 794 | for (size_t i=sz; i<ctsz; i++) { |
| 795 | accum = (accum<<1) | (accum & 0x01); |
| 796 | history[i] = accum; |
| 797 | } |
| 798 | } |
| 799 | |
| 800 | // Precompute metric tables. |
| 801 | float matchCostTable[ctsz]; |
| 802 | float mismatchCostTable[ctsz]; |
| 803 | { |
| 804 | const float *dp = in.begin(); |
| 805 | for (size_t i=0; i<sz; i++) { |
| 806 | // pVal is the probability that a bit is correct. |
| 807 | // ipVal is the probability that a bit is incorrect. |
| 808 | float pVal = dp[i]; |
| 809 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 810 | float ipVal = 1.0F-pVal; |
| 811 | // This is a cheap approximation to an ideal cost function. |
| 812 | if (pVal<0.01F) pVal = 0.01; |
| 813 | if (ipVal<0.01F) ipVal = 0.01; |
| 814 | matchCostTable[i] = 0.25F/ipVal; |
| 815 | mismatchCostTable[i] = 0.25F/pVal; |
| 816 | } |
| 817 | |
| 818 | // pad end of table with unknowns |
| 819 | for (size_t i=sz; i<ctsz; i++) { |
| 820 | matchCostTable[i] = 0.5F; |
| 821 | mismatchCostTable[i] = 0.5F; |
| 822 | } |
| 823 | } |
| 824 | |
| 825 | { |
| 826 | decoder.initializeStates(); |
| 827 | // Each sample of history[] carries its history. |
| 828 | // So we only have to process every iRate-th sample. |
| 829 | const unsigned step = decoder.iRate(); |
| 830 | // input pointer |
| 831 | const uint32_t *ip = history + step - 1; |
| 832 | // output pointers |
| 833 | char *op = target.begin(); |
| 834 | const char *const opt = target.end(); |
| 835 | // table pointers |
| 836 | const float* match = matchCostTable; |
| 837 | const float* mismatch = mismatchCostTable; |
| 838 | size_t oCount = 0; |
| 839 | while (op<opt) { |
| 840 | // Viterbi algorithm |
| 841 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 842 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 843 | const ViterbiTCH_AFS7_95::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 844 | ip += step; |
| 845 | match += step; |
| 846 | mismatch += step; |
| 847 | // output |
| 848 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 849 | oCount++; |
| 850 | } |
| 851 | } |
| 852 | } |
| 853 | |
| 854 | |
| 855 | |
| 856 | ViterbiTCH_AFS7_4::ViterbiTCH_AFS7_4() |
| 857 | { |
| 858 | assert(mDeferral < 32); |
| 859 | mCoeffs[0] = 0x01b; |
| 860 | mCoeffsFB[0] = 0x01f; |
| 861 | mCoeffs[1] = 0x015; |
| 862 | mCoeffsFB[1] = 0x01f; |
| 863 | mCoeffs[2] = 0x01f; |
| 864 | mCoeffsFB[2] = 0x01f; |
| 865 | for (unsigned i = 0; i < mIRate; i++) { |
| 866 | computeStateTables(i); |
| 867 | } |
| 868 | computeGeneratorTable(); |
| 869 | } |
| 870 | |
| 871 | |
| 872 | |
| 873 | |
| 874 | void ViterbiTCH_AFS7_4::initializeStates() |
| 875 | { |
| 876 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 877 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 878 | } |
| 879 | |
| 880 | |
| 881 | |
| 882 | void ViterbiTCH_AFS7_4::computeStateTables(unsigned g) |
| 883 | { |
| 884 | assert(g<mIRate); |
| 885 | for (unsigned state=0; state<mIStates; state++) { |
| 886 | for (unsigned in = 0; in <= 1; in++) { |
| 887 | uint32_t inputVal = (state<<1) | in; |
| 888 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 889 | } |
| 890 | } |
| 891 | } |
| 892 | |
| 893 | void ViterbiTCH_AFS7_4::computeGeneratorTable() |
| 894 | { |
| 895 | for (unsigned index=0; index<mIStates*2; index++) { |
| 896 | uint32_t t = 0; |
| 897 | for (unsigned i = 0; i < mIRate; i++) { |
| 898 | t = (t << 1) | mStateTable[i][index]; |
| 899 | } |
| 900 | mGeneratorTable[index] = t; |
| 901 | } |
| 902 | } |
| 903 | |
| 904 | |
| 905 | |
| 906 | |
| 907 | |
| 908 | |
| 909 | void ViterbiTCH_AFS7_4::branchCandidates() |
| 910 | { |
| 911 | // Branch to generate new input states. |
| 912 | const vCand *sp = mSurvivors; |
| 913 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 914 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 915 | for (unsigned in = 0; in <= 1; in++) { |
| 916 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 917 | mCandidates[cand+in].cost = sp->cost; |
| 918 | uint32_t outputs = oStateShifted; |
| 919 | for (unsigned out = 0; out < mIRate; out++) { |
| 920 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 921 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 922 | mCandidates[cand+in].rState[out] = rState; |
| 923 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 924 | } |
| 925 | mCandidates[cand+in].oState = outputs; |
| 926 | } |
| 927 | sp++; |
| 928 | } |
| 929 | } |
| 930 | |
| 931 | |
| 932 | void ViterbiTCH_AFS7_4::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 933 | { |
| 934 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 935 | for (unsigned i=0; i<mNumCands; i++) { |
| 936 | vCand& thisCand = mCandidates[i]; |
| 937 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 938 | for (unsigned i = 0; i < mIRate; i++) { |
| 939 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 940 | } |
| 941 | } |
| 942 | } |
| 943 | |
| 944 | |
| 945 | void ViterbiTCH_AFS7_4::pruneCandidates() |
| 946 | { |
| 947 | const vCand* c1 = mCandidates; // 0-prefix |
| 948 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 949 | for (unsigned i=0; i<mIStates; i++) { |
| 950 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 951 | else mSurvivors[i] = c2[i]; |
| 952 | } |
| 953 | } |
| 954 | |
| 955 | |
| 956 | const ViterbiTCH_AFS7_4::vCand& ViterbiTCH_AFS7_4::minCost() const |
| 957 | { |
| 958 | int minIndex = 0; |
| 959 | float minCost = mSurvivors[0].cost; |
| 960 | for (unsigned i=1; i<mIStates; i++) { |
| 961 | const float thisCost = mSurvivors[i].cost; |
| 962 | if (thisCost>=minCost) continue; |
| 963 | minCost = thisCost; |
| 964 | minIndex=i; |
| 965 | } |
| 966 | return mSurvivors[minIndex]; |
| 967 | } |
| 968 | |
| 969 | |
| 970 | const ViterbiTCH_AFS7_4::vCand& ViterbiTCH_AFS7_4::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 971 | { |
| 972 | branchCandidates(); |
| 973 | getSoftCostMetrics(inSample,probs,iprobs); |
| 974 | pruneCandidates(); |
| 975 | return minCost(); |
| 976 | } |
| 977 | |
| 978 | |
| 979 | |
| 980 | void ViterbiTCH_AFS7_4::decode(const SoftVector &in, BitVector& target) |
| 981 | { |
| 982 | ViterbiTCH_AFS7_4 &decoder = *this; |
| 983 | const size_t sz = in.size() - 12; |
| 984 | const unsigned deferral = decoder.deferral(); |
| 985 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 986 | assert(sz == decoder.iRate()*target.size()); |
| 987 | |
| 988 | // Build a "history" array where each element contains the full history. |
| 989 | uint32_t history[ctsz]; |
| 990 | { |
| 991 | BitVector bits = in.sliced(); |
| 992 | uint32_t accum = 0; |
| 993 | for (size_t i=0; i<sz; i++) { |
| 994 | accum = (accum<<1) | bits.bit(i); |
| 995 | history[i] = accum; |
| 996 | } |
| 997 | // Repeat last bit at the end. |
| 998 | for (size_t i=sz; i<ctsz; i++) { |
| 999 | accum = (accum<<1) | (accum & 0x01); |
| 1000 | history[i] = accum; |
| 1001 | } |
| 1002 | } |
| 1003 | |
| 1004 | // Precompute metric tables. |
| 1005 | float matchCostTable[ctsz]; |
| 1006 | float mismatchCostTable[ctsz]; |
| 1007 | { |
| 1008 | const float *dp = in.begin(); |
| 1009 | for (size_t i=0; i<sz; i++) { |
| 1010 | // pVal is the probability that a bit is correct. |
| 1011 | // ipVal is the probability that a bit is incorrect. |
| 1012 | float pVal = dp[i]; |
| 1013 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1014 | float ipVal = 1.0F-pVal; |
| 1015 | // This is a cheap approximation to an ideal cost function. |
| 1016 | if (pVal<0.01F) pVal = 0.01; |
| 1017 | if (ipVal<0.01F) ipVal = 0.01; |
| 1018 | matchCostTable[i] = 0.25F/ipVal; |
| 1019 | mismatchCostTable[i] = 0.25F/pVal; |
| 1020 | } |
| 1021 | |
| 1022 | // pad end of table with unknowns |
| 1023 | for (size_t i=sz; i<ctsz; i++) { |
| 1024 | matchCostTable[i] = 0.5F; |
| 1025 | mismatchCostTable[i] = 0.5F; |
| 1026 | } |
| 1027 | } |
| 1028 | |
| 1029 | { |
| 1030 | decoder.initializeStates(); |
| 1031 | // Each sample of history[] carries its history. |
| 1032 | // So we only have to process every iRate-th sample. |
| 1033 | const unsigned step = decoder.iRate(); |
| 1034 | // input pointer |
| 1035 | const uint32_t *ip = history + step - 1; |
| 1036 | // output pointers |
| 1037 | char *op = target.begin(); |
| 1038 | const char *const opt = target.end(); |
| 1039 | // table pointers |
| 1040 | const float* match = matchCostTable; |
| 1041 | const float* mismatch = mismatchCostTable; |
| 1042 | size_t oCount = 0; |
| 1043 | while (op<opt) { |
| 1044 | // Viterbi algorithm |
| 1045 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1046 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1047 | const ViterbiTCH_AFS7_4::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1048 | ip += step; |
| 1049 | match += step; |
| 1050 | mismatch += step; |
| 1051 | // output |
| 1052 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1053 | oCount++; |
| 1054 | } |
| 1055 | } |
| 1056 | } |
| 1057 | |
| 1058 | |
| 1059 | |
| 1060 | ViterbiTCH_AFS6_7::ViterbiTCH_AFS6_7() |
| 1061 | { |
| 1062 | assert(mDeferral < 32); |
| 1063 | mCoeffs[0] = 0x01b; |
| 1064 | mCoeffsFB[0] = 0x01f; |
| 1065 | mCoeffs[1] = 0x015; |
| 1066 | mCoeffsFB[1] = 0x01f; |
| 1067 | mCoeffs[2] = 0x01f; |
| 1068 | mCoeffsFB[2] = 0x01f; |
| 1069 | mCoeffs[3] = 0x01f; |
| 1070 | mCoeffsFB[3] = 0x01f; |
| 1071 | for (unsigned i = 0; i < mIRate; i++) { |
| 1072 | computeStateTables(i); |
| 1073 | } |
| 1074 | computeGeneratorTable(); |
| 1075 | } |
| 1076 | |
| 1077 | |
| 1078 | |
| 1079 | |
| 1080 | void ViterbiTCH_AFS6_7::initializeStates() |
| 1081 | { |
| 1082 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 1083 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 1084 | } |
| 1085 | |
| 1086 | |
| 1087 | |
| 1088 | void ViterbiTCH_AFS6_7::computeStateTables(unsigned g) |
| 1089 | { |
| 1090 | assert(g<mIRate); |
| 1091 | for (unsigned state=0; state<mIStates; state++) { |
| 1092 | for (unsigned in = 0; in <= 1; in++) { |
| 1093 | uint32_t inputVal = (state<<1) | in; |
| 1094 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 1095 | } |
| 1096 | } |
| 1097 | } |
| 1098 | |
| 1099 | void ViterbiTCH_AFS6_7::computeGeneratorTable() |
| 1100 | { |
| 1101 | for (unsigned index=0; index<mIStates*2; index++) { |
| 1102 | uint32_t t = 0; |
| 1103 | for (unsigned i = 0; i < mIRate; i++) { |
| 1104 | t = (t << 1) | mStateTable[i][index]; |
| 1105 | } |
| 1106 | mGeneratorTable[index] = t; |
| 1107 | } |
| 1108 | } |
| 1109 | |
| 1110 | |
| 1111 | |
| 1112 | |
| 1113 | |
| 1114 | |
| 1115 | void ViterbiTCH_AFS6_7::branchCandidates() |
| 1116 | { |
| 1117 | // Branch to generate new input states. |
| 1118 | const vCand *sp = mSurvivors; |
| 1119 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 1120 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 1121 | for (unsigned in = 0; in <= 1; in++) { |
| 1122 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 1123 | mCandidates[cand+in].cost = sp->cost; |
| 1124 | uint32_t outputs = oStateShifted; |
| 1125 | for (unsigned out = 0; out < mIRate; out++) { |
| 1126 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 1127 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 1128 | mCandidates[cand+in].rState[out] = rState; |
| 1129 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 1130 | } |
| 1131 | mCandidates[cand+in].oState = outputs; |
| 1132 | } |
| 1133 | sp++; |
| 1134 | } |
| 1135 | } |
| 1136 | |
| 1137 | |
| 1138 | void ViterbiTCH_AFS6_7::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 1139 | { |
| 1140 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 1141 | for (unsigned i=0; i<mNumCands; i++) { |
| 1142 | vCand& thisCand = mCandidates[i]; |
| 1143 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 1144 | for (unsigned i = 0; i < mIRate; i++) { |
| 1145 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 1146 | } |
| 1147 | } |
| 1148 | } |
| 1149 | |
| 1150 | |
| 1151 | void ViterbiTCH_AFS6_7::pruneCandidates() |
| 1152 | { |
| 1153 | const vCand* c1 = mCandidates; // 0-prefix |
| 1154 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 1155 | for (unsigned i=0; i<mIStates; i++) { |
| 1156 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 1157 | else mSurvivors[i] = c2[i]; |
| 1158 | } |
| 1159 | } |
| 1160 | |
| 1161 | |
| 1162 | const ViterbiTCH_AFS6_7::vCand& ViterbiTCH_AFS6_7::minCost() const |
| 1163 | { |
| 1164 | int minIndex = 0; |
| 1165 | float minCost = mSurvivors[0].cost; |
| 1166 | for (unsigned i=1; i<mIStates; i++) { |
| 1167 | const float thisCost = mSurvivors[i].cost; |
| 1168 | if (thisCost>=minCost) continue; |
| 1169 | minCost = thisCost; |
| 1170 | minIndex=i; |
| 1171 | } |
| 1172 | return mSurvivors[minIndex]; |
| 1173 | } |
| 1174 | |
| 1175 | |
| 1176 | const ViterbiTCH_AFS6_7::vCand& ViterbiTCH_AFS6_7::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 1177 | { |
| 1178 | branchCandidates(); |
| 1179 | getSoftCostMetrics(inSample,probs,iprobs); |
| 1180 | pruneCandidates(); |
| 1181 | return minCost(); |
| 1182 | } |
| 1183 | |
| 1184 | |
| 1185 | |
| 1186 | void ViterbiTCH_AFS6_7::decode(const SoftVector &in, BitVector& target) |
| 1187 | { |
| 1188 | ViterbiTCH_AFS6_7 &decoder = *this; |
| 1189 | const size_t sz = in.size() - 16; |
| 1190 | const unsigned deferral = decoder.deferral(); |
| 1191 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 1192 | assert(sz == decoder.iRate()*target.size()); |
| 1193 | |
| 1194 | // Build a "history" array where each element contains the full history. |
| 1195 | uint32_t history[ctsz]; |
| 1196 | { |
| 1197 | BitVector bits = in.sliced(); |
| 1198 | uint32_t accum = 0; |
| 1199 | for (size_t i=0; i<sz; i++) { |
| 1200 | accum = (accum<<1) | bits.bit(i); |
| 1201 | history[i] = accum; |
| 1202 | } |
| 1203 | // Repeat last bit at the end. |
| 1204 | for (size_t i=sz; i<ctsz; i++) { |
| 1205 | accum = (accum<<1) | (accum & 0x01); |
| 1206 | history[i] = accum; |
| 1207 | } |
| 1208 | } |
| 1209 | |
| 1210 | // Precompute metric tables. |
| 1211 | float matchCostTable[ctsz]; |
| 1212 | float mismatchCostTable[ctsz]; |
| 1213 | { |
| 1214 | const float *dp = in.begin(); |
| 1215 | for (size_t i=0; i<sz; i++) { |
| 1216 | // pVal is the probability that a bit is correct. |
| 1217 | // ipVal is the probability that a bit is incorrect. |
| 1218 | float pVal = dp[i]; |
| 1219 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1220 | float ipVal = 1.0F-pVal; |
| 1221 | // This is a cheap approximation to an ideal cost function. |
| 1222 | if (pVal<0.01F) pVal = 0.01; |
| 1223 | if (ipVal<0.01F) ipVal = 0.01; |
| 1224 | matchCostTable[i] = 0.25F/ipVal; |
| 1225 | mismatchCostTable[i] = 0.25F/pVal; |
| 1226 | } |
| 1227 | |
| 1228 | // pad end of table with unknowns |
| 1229 | for (size_t i=sz; i<ctsz; i++) { |
| 1230 | matchCostTable[i] = 0.5F; |
| 1231 | mismatchCostTable[i] = 0.5F; |
| 1232 | } |
| 1233 | } |
| 1234 | |
| 1235 | { |
| 1236 | decoder.initializeStates(); |
| 1237 | // Each sample of history[] carries its history. |
| 1238 | // So we only have to process every iRate-th sample. |
| 1239 | const unsigned step = decoder.iRate(); |
| 1240 | // input pointer |
| 1241 | const uint32_t *ip = history + step - 1; |
| 1242 | // output pointers |
| 1243 | char *op = target.begin(); |
| 1244 | const char *const opt = target.end(); |
| 1245 | // table pointers |
| 1246 | const float* match = matchCostTable; |
| 1247 | const float* mismatch = mismatchCostTable; |
| 1248 | size_t oCount = 0; |
| 1249 | while (op<opt) { |
| 1250 | // Viterbi algorithm |
| 1251 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1252 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1253 | const ViterbiTCH_AFS6_7::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1254 | ip += step; |
| 1255 | match += step; |
| 1256 | mismatch += step; |
| 1257 | // output |
| 1258 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1259 | oCount++; |
| 1260 | } |
| 1261 | } |
| 1262 | } |
| 1263 | |
| 1264 | |
| 1265 | |
| 1266 | ViterbiTCH_AFS5_9::ViterbiTCH_AFS5_9() |
| 1267 | { |
| 1268 | assert(mDeferral < 32); |
| 1269 | mCoeffs[0] = 0x06d; |
| 1270 | mCoeffsFB[0] = 0x05f; |
| 1271 | mCoeffs[1] = 0x053; |
| 1272 | mCoeffsFB[1] = 0x05f; |
| 1273 | mCoeffs[2] = 0x05f; |
| 1274 | mCoeffsFB[2] = 0x05f; |
| 1275 | mCoeffs[3] = 0x05f; |
| 1276 | mCoeffsFB[3] = 0x05f; |
| 1277 | for (unsigned i = 0; i < mIRate; i++) { |
| 1278 | computeStateTables(i); |
| 1279 | } |
| 1280 | computeGeneratorTable(); |
| 1281 | } |
| 1282 | |
| 1283 | |
| 1284 | |
| 1285 | |
| 1286 | void ViterbiTCH_AFS5_9::initializeStates() |
| 1287 | { |
| 1288 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 1289 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 1290 | } |
| 1291 | |
| 1292 | |
| 1293 | |
| 1294 | void ViterbiTCH_AFS5_9::computeStateTables(unsigned g) |
| 1295 | { |
| 1296 | assert(g<mIRate); |
| 1297 | for (unsigned state=0; state<mIStates; state++) { |
| 1298 | for (unsigned in = 0; in <= 1; in++) { |
| 1299 | uint32_t inputVal = (state<<1) | in; |
| 1300 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 1301 | } |
| 1302 | } |
| 1303 | } |
| 1304 | |
| 1305 | void ViterbiTCH_AFS5_9::computeGeneratorTable() |
| 1306 | { |
| 1307 | for (unsigned index=0; index<mIStates*2; index++) { |
| 1308 | uint32_t t = 0; |
| 1309 | for (unsigned i = 0; i < mIRate; i++) { |
| 1310 | t = (t << 1) | mStateTable[i][index]; |
| 1311 | } |
| 1312 | mGeneratorTable[index] = t; |
| 1313 | } |
| 1314 | } |
| 1315 | |
| 1316 | |
| 1317 | |
| 1318 | |
| 1319 | |
| 1320 | |
| 1321 | void ViterbiTCH_AFS5_9::branchCandidates() |
| 1322 | { |
| 1323 | // Branch to generate new input states. |
| 1324 | const vCand *sp = mSurvivors; |
| 1325 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 1326 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 1327 | for (unsigned in = 0; in <= 1; in++) { |
| 1328 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 1329 | mCandidates[cand+in].cost = sp->cost; |
| 1330 | uint32_t outputs = oStateShifted; |
| 1331 | for (unsigned out = 0; out < mIRate; out++) { |
| 1332 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 1333 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 1334 | mCandidates[cand+in].rState[out] = rState; |
| 1335 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 1336 | } |
| 1337 | mCandidates[cand+in].oState = outputs; |
| 1338 | } |
| 1339 | sp++; |
| 1340 | } |
| 1341 | } |
| 1342 | |
| 1343 | |
| 1344 | void ViterbiTCH_AFS5_9::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 1345 | { |
| 1346 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 1347 | for (unsigned i=0; i<mNumCands; i++) { |
| 1348 | vCand& thisCand = mCandidates[i]; |
| 1349 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 1350 | for (unsigned i = 0; i < mIRate; i++) { |
| 1351 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 1352 | } |
| 1353 | } |
| 1354 | } |
| 1355 | |
| 1356 | |
| 1357 | void ViterbiTCH_AFS5_9::pruneCandidates() |
| 1358 | { |
| 1359 | const vCand* c1 = mCandidates; // 0-prefix |
| 1360 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 1361 | for (unsigned i=0; i<mIStates; i++) { |
| 1362 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 1363 | else mSurvivors[i] = c2[i]; |
| 1364 | } |
| 1365 | } |
| 1366 | |
| 1367 | |
| 1368 | const ViterbiTCH_AFS5_9::vCand& ViterbiTCH_AFS5_9::minCost() const |
| 1369 | { |
| 1370 | int minIndex = 0; |
| 1371 | float minCost = mSurvivors[0].cost; |
| 1372 | for (unsigned i=1; i<mIStates; i++) { |
| 1373 | const float thisCost = mSurvivors[i].cost; |
| 1374 | if (thisCost>=minCost) continue; |
| 1375 | minCost = thisCost; |
| 1376 | minIndex=i; |
| 1377 | } |
| 1378 | return mSurvivors[minIndex]; |
| 1379 | } |
| 1380 | |
| 1381 | |
| 1382 | const ViterbiTCH_AFS5_9::vCand& ViterbiTCH_AFS5_9::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 1383 | { |
| 1384 | branchCandidates(); |
| 1385 | getSoftCostMetrics(inSample,probs,iprobs); |
| 1386 | pruneCandidates(); |
| 1387 | return minCost(); |
| 1388 | } |
| 1389 | |
| 1390 | |
| 1391 | |
| 1392 | void ViterbiTCH_AFS5_9::decode(const SoftVector &in, BitVector& target) |
| 1393 | { |
| 1394 | ViterbiTCH_AFS5_9 &decoder = *this; |
| 1395 | const size_t sz = in.size() - 24; |
| 1396 | const unsigned deferral = decoder.deferral(); |
| 1397 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 1398 | assert(sz == decoder.iRate()*target.size()); |
| 1399 | |
| 1400 | // Build a "history" array where each element contains the full history. |
| 1401 | uint32_t history[ctsz]; |
| 1402 | { |
| 1403 | BitVector bits = in.sliced(); |
| 1404 | uint32_t accum = 0; |
| 1405 | for (size_t i=0; i<sz; i++) { |
| 1406 | accum = (accum<<1) | bits.bit(i); |
| 1407 | history[i] = accum; |
| 1408 | } |
| 1409 | // Repeat last bit at the end. |
| 1410 | for (size_t i=sz; i<ctsz; i++) { |
| 1411 | accum = (accum<<1) | (accum & 0x01); |
| 1412 | history[i] = accum; |
| 1413 | } |
| 1414 | } |
| 1415 | |
| 1416 | // Precompute metric tables. |
| 1417 | float matchCostTable[ctsz]; |
| 1418 | float mismatchCostTable[ctsz]; |
| 1419 | { |
| 1420 | const float *dp = in.begin(); |
| 1421 | for (size_t i=0; i<sz; i++) { |
| 1422 | // pVal is the probability that a bit is correct. |
| 1423 | // ipVal is the probability that a bit is incorrect. |
| 1424 | float pVal = dp[i]; |
| 1425 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1426 | float ipVal = 1.0F-pVal; |
| 1427 | // This is a cheap approximation to an ideal cost function. |
| 1428 | if (pVal<0.01F) pVal = 0.01; |
| 1429 | if (ipVal<0.01F) ipVal = 0.01; |
| 1430 | matchCostTable[i] = 0.25F/ipVal; |
| 1431 | mismatchCostTable[i] = 0.25F/pVal; |
| 1432 | } |
| 1433 | |
| 1434 | // pad end of table with unknowns |
| 1435 | for (size_t i=sz; i<ctsz; i++) { |
| 1436 | matchCostTable[i] = 0.5F; |
| 1437 | mismatchCostTable[i] = 0.5F; |
| 1438 | } |
| 1439 | } |
| 1440 | |
| 1441 | { |
| 1442 | decoder.initializeStates(); |
| 1443 | // Each sample of history[] carries its history. |
| 1444 | // So we only have to process every iRate-th sample. |
| 1445 | const unsigned step = decoder.iRate(); |
| 1446 | // input pointer |
| 1447 | const uint32_t *ip = history + step - 1; |
| 1448 | // output pointers |
| 1449 | char *op = target.begin(); |
| 1450 | const char *const opt = target.end(); |
| 1451 | // table pointers |
| 1452 | const float* match = matchCostTable; |
| 1453 | const float* mismatch = mismatchCostTable; |
| 1454 | size_t oCount = 0; |
| 1455 | while (op<opt) { |
| 1456 | // Viterbi algorithm |
| 1457 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1458 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1459 | const ViterbiTCH_AFS5_9::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1460 | ip += step; |
| 1461 | match += step; |
| 1462 | mismatch += step; |
| 1463 | // output |
| 1464 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1465 | oCount++; |
| 1466 | } |
| 1467 | } |
| 1468 | } |
| 1469 | |
| 1470 | |
| 1471 | |
| 1472 | ViterbiTCH_AFS5_15::ViterbiTCH_AFS5_15() |
| 1473 | { |
| 1474 | assert(mDeferral < 32); |
| 1475 | mCoeffs[0] = 0x01b; |
| 1476 | mCoeffsFB[0] = 0x01f; |
| 1477 | mCoeffs[1] = 0x01b; |
| 1478 | mCoeffsFB[1] = 0x01f; |
| 1479 | mCoeffs[2] = 0x015; |
| 1480 | mCoeffsFB[2] = 0x01f; |
| 1481 | mCoeffs[3] = 0x01f; |
| 1482 | mCoeffsFB[3] = 0x01f; |
| 1483 | mCoeffs[4] = 0x01f; |
| 1484 | mCoeffsFB[4] = 0x01f; |
| 1485 | for (unsigned i = 0; i < mIRate; i++) { |
| 1486 | computeStateTables(i); |
| 1487 | } |
| 1488 | computeGeneratorTable(); |
| 1489 | } |
| 1490 | |
| 1491 | |
| 1492 | |
| 1493 | |
| 1494 | void ViterbiTCH_AFS5_15::initializeStates() |
| 1495 | { |
| 1496 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 1497 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 1498 | } |
| 1499 | |
| 1500 | |
| 1501 | |
| 1502 | void ViterbiTCH_AFS5_15::computeStateTables(unsigned g) |
| 1503 | { |
| 1504 | assert(g<mIRate); |
| 1505 | for (unsigned state=0; state<mIStates; state++) { |
| 1506 | for (unsigned in = 0; in <= 1; in++) { |
| 1507 | uint32_t inputVal = (state<<1) | in; |
| 1508 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 1509 | } |
| 1510 | } |
| 1511 | } |
| 1512 | |
| 1513 | void ViterbiTCH_AFS5_15::computeGeneratorTable() |
| 1514 | { |
| 1515 | for (unsigned index=0; index<mIStates*2; index++) { |
| 1516 | uint32_t t = 0; |
| 1517 | for (unsigned i = 0; i < mIRate; i++) { |
| 1518 | t = (t << 1) | mStateTable[i][index]; |
| 1519 | } |
| 1520 | mGeneratorTable[index] = t; |
| 1521 | } |
| 1522 | } |
| 1523 | |
| 1524 | |
| 1525 | |
| 1526 | |
| 1527 | |
| 1528 | |
| 1529 | void ViterbiTCH_AFS5_15::branchCandidates() |
| 1530 | { |
| 1531 | // Branch to generate new input states. |
| 1532 | const vCand *sp = mSurvivors; |
| 1533 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 1534 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 1535 | for (unsigned in = 0; in <= 1; in++) { |
| 1536 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 1537 | mCandidates[cand+in].cost = sp->cost; |
| 1538 | uint32_t outputs = oStateShifted; |
| 1539 | for (unsigned out = 0; out < mIRate; out++) { |
| 1540 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 1541 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 1542 | mCandidates[cand+in].rState[out] = rState; |
| 1543 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 1544 | } |
| 1545 | mCandidates[cand+in].oState = outputs; |
| 1546 | } |
| 1547 | sp++; |
| 1548 | } |
| 1549 | } |
| 1550 | |
| 1551 | |
| 1552 | void ViterbiTCH_AFS5_15::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 1553 | { |
| 1554 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 1555 | for (unsigned i=0; i<mNumCands; i++) { |
| 1556 | vCand& thisCand = mCandidates[i]; |
| 1557 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 1558 | for (unsigned i = 0; i < mIRate; i++) { |
| 1559 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 1560 | } |
| 1561 | } |
| 1562 | } |
| 1563 | |
| 1564 | |
| 1565 | void ViterbiTCH_AFS5_15::pruneCandidates() |
| 1566 | { |
| 1567 | const vCand* c1 = mCandidates; // 0-prefix |
| 1568 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 1569 | for (unsigned i=0; i<mIStates; i++) { |
| 1570 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 1571 | else mSurvivors[i] = c2[i]; |
| 1572 | } |
| 1573 | } |
| 1574 | |
| 1575 | |
| 1576 | const ViterbiTCH_AFS5_15::vCand& ViterbiTCH_AFS5_15::minCost() const |
| 1577 | { |
| 1578 | int minIndex = 0; |
| 1579 | float minCost = mSurvivors[0].cost; |
| 1580 | for (unsigned i=1; i<mIStates; i++) { |
| 1581 | const float thisCost = mSurvivors[i].cost; |
| 1582 | if (thisCost>=minCost) continue; |
| 1583 | minCost = thisCost; |
| 1584 | minIndex=i; |
| 1585 | } |
| 1586 | return mSurvivors[minIndex]; |
| 1587 | } |
| 1588 | |
| 1589 | |
| 1590 | const ViterbiTCH_AFS5_15::vCand& ViterbiTCH_AFS5_15::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 1591 | { |
| 1592 | branchCandidates(); |
| 1593 | getSoftCostMetrics(inSample,probs,iprobs); |
| 1594 | pruneCandidates(); |
| 1595 | return minCost(); |
| 1596 | } |
| 1597 | |
| 1598 | |
| 1599 | |
| 1600 | void ViterbiTCH_AFS5_15::decode(const SoftVector &in, BitVector& target) |
| 1601 | { |
| 1602 | ViterbiTCH_AFS5_15 &decoder = *this; |
| 1603 | const size_t sz = in.size() - 20; |
| 1604 | const unsigned deferral = decoder.deferral(); |
| 1605 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 1606 | assert(sz == decoder.iRate()*target.size()); |
| 1607 | |
| 1608 | // Build a "history" array where each element contains the full history. |
| 1609 | uint32_t history[ctsz]; |
| 1610 | { |
| 1611 | BitVector bits = in.sliced(); |
| 1612 | uint32_t accum = 0; |
| 1613 | for (size_t i=0; i<sz; i++) { |
| 1614 | accum = (accum<<1) | bits.bit(i); |
| 1615 | history[i] = accum; |
| 1616 | } |
| 1617 | // Repeat last bit at the end. |
| 1618 | for (size_t i=sz; i<ctsz; i++) { |
| 1619 | accum = (accum<<1) | (accum & 0x01); |
| 1620 | history[i] = accum; |
| 1621 | } |
| 1622 | } |
| 1623 | |
| 1624 | // Precompute metric tables. |
| 1625 | float matchCostTable[ctsz]; |
| 1626 | float mismatchCostTable[ctsz]; |
| 1627 | { |
| 1628 | const float *dp = in.begin(); |
| 1629 | for (size_t i=0; i<sz; i++) { |
| 1630 | // pVal is the probability that a bit is correct. |
| 1631 | // ipVal is the probability that a bit is incorrect. |
| 1632 | float pVal = dp[i]; |
| 1633 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1634 | float ipVal = 1.0F-pVal; |
| 1635 | // This is a cheap approximation to an ideal cost function. |
| 1636 | if (pVal<0.01F) pVal = 0.01; |
| 1637 | if (ipVal<0.01F) ipVal = 0.01; |
| 1638 | matchCostTable[i] = 0.25F/ipVal; |
| 1639 | mismatchCostTable[i] = 0.25F/pVal; |
| 1640 | } |
| 1641 | |
| 1642 | // pad end of table with unknowns |
| 1643 | for (size_t i=sz; i<ctsz; i++) { |
| 1644 | matchCostTable[i] = 0.5F; |
| 1645 | mismatchCostTable[i] = 0.5F; |
| 1646 | } |
| 1647 | } |
| 1648 | |
| 1649 | { |
| 1650 | decoder.initializeStates(); |
| 1651 | // Each sample of history[] carries its history. |
| 1652 | // So we only have to process every iRate-th sample. |
| 1653 | const unsigned step = decoder.iRate(); |
| 1654 | // input pointer |
| 1655 | const uint32_t *ip = history + step - 1; |
| 1656 | // output pointers |
| 1657 | char *op = target.begin(); |
| 1658 | const char *const opt = target.end(); |
| 1659 | // table pointers |
| 1660 | const float* match = matchCostTable; |
| 1661 | const float* mismatch = mismatchCostTable; |
| 1662 | size_t oCount = 0; |
| 1663 | while (op<opt) { |
| 1664 | // Viterbi algorithm |
| 1665 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1666 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1667 | const ViterbiTCH_AFS5_15::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1668 | ip += step; |
| 1669 | match += step; |
| 1670 | mismatch += step; |
| 1671 | // output |
| 1672 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1673 | oCount++; |
| 1674 | } |
| 1675 | } |
| 1676 | } |
| 1677 | |
| 1678 | |
| 1679 | |
| 1680 | ViterbiTCH_AFS4_75::ViterbiTCH_AFS4_75() |
| 1681 | { |
| 1682 | assert(mDeferral < 32); |
| 1683 | mCoeffs[0] = 0x06d; |
| 1684 | mCoeffsFB[0] = 0x05f; |
| 1685 | mCoeffs[1] = 0x06d; |
| 1686 | mCoeffsFB[1] = 0x05f; |
| 1687 | mCoeffs[2] = 0x053; |
| 1688 | mCoeffsFB[2] = 0x05f; |
| 1689 | mCoeffs[3] = 0x05f; |
| 1690 | mCoeffsFB[3] = 0x05f; |
| 1691 | mCoeffs[4] = 0x05f; |
| 1692 | mCoeffsFB[4] = 0x05f; |
| 1693 | for (unsigned i = 0; i < mIRate; i++) { |
| 1694 | computeStateTables(i); |
| 1695 | } |
| 1696 | computeGeneratorTable(); |
| 1697 | } |
| 1698 | |
| 1699 | |
| 1700 | |
| 1701 | |
| 1702 | void ViterbiTCH_AFS4_75::initializeStates() |
| 1703 | { |
| 1704 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 1705 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 1706 | } |
| 1707 | |
| 1708 | |
| 1709 | |
| 1710 | void ViterbiTCH_AFS4_75::computeStateTables(unsigned g) |
| 1711 | { |
| 1712 | assert(g<mIRate); |
| 1713 | for (unsigned state=0; state<mIStates; state++) { |
| 1714 | for (unsigned in = 0; in <= 1; in++) { |
| 1715 | uint32_t inputVal = (state<<1) | in; |
| 1716 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 1717 | } |
| 1718 | } |
| 1719 | } |
| 1720 | |
| 1721 | void ViterbiTCH_AFS4_75::computeGeneratorTable() |
| 1722 | { |
| 1723 | for (unsigned index=0; index<mIStates*2; index++) { |
| 1724 | uint32_t t = 0; |
| 1725 | for (unsigned i = 0; i < mIRate; i++) { |
| 1726 | t = (t << 1) | mStateTable[i][index]; |
| 1727 | } |
| 1728 | mGeneratorTable[index] = t; |
| 1729 | } |
| 1730 | } |
| 1731 | |
| 1732 | |
| 1733 | |
| 1734 | |
| 1735 | |
| 1736 | |
| 1737 | void ViterbiTCH_AFS4_75::branchCandidates() |
| 1738 | { |
| 1739 | // Branch to generate new input states. |
| 1740 | const vCand *sp = mSurvivors; |
| 1741 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 1742 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 1743 | for (unsigned in = 0; in <= 1; in++) { |
| 1744 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 1745 | mCandidates[cand+in].cost = sp->cost; |
| 1746 | uint32_t outputs = oStateShifted; |
| 1747 | for (unsigned out = 0; out < mIRate; out++) { |
| 1748 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 1749 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 1750 | mCandidates[cand+in].rState[out] = rState; |
| 1751 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 1752 | } |
| 1753 | mCandidates[cand+in].oState = outputs; |
| 1754 | } |
| 1755 | sp++; |
| 1756 | } |
| 1757 | } |
| 1758 | |
| 1759 | |
| 1760 | void ViterbiTCH_AFS4_75::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 1761 | { |
| 1762 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 1763 | for (unsigned i=0; i<mNumCands; i++) { |
| 1764 | vCand& thisCand = mCandidates[i]; |
| 1765 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 1766 | for (unsigned i = 0; i < mIRate; i++) { |
| 1767 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 1768 | } |
| 1769 | } |
| 1770 | } |
| 1771 | |
| 1772 | |
| 1773 | void ViterbiTCH_AFS4_75::pruneCandidates() |
| 1774 | { |
| 1775 | const vCand* c1 = mCandidates; // 0-prefix |
| 1776 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 1777 | for (unsigned i=0; i<mIStates; i++) { |
| 1778 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 1779 | else mSurvivors[i] = c2[i]; |
| 1780 | } |
| 1781 | } |
| 1782 | |
| 1783 | |
| 1784 | const ViterbiTCH_AFS4_75::vCand& ViterbiTCH_AFS4_75::minCost() const |
| 1785 | { |
| 1786 | int minIndex = 0; |
| 1787 | float minCost = mSurvivors[0].cost; |
| 1788 | for (unsigned i=1; i<mIStates; i++) { |
| 1789 | const float thisCost = mSurvivors[i].cost; |
| 1790 | if (thisCost>=minCost) continue; |
| 1791 | minCost = thisCost; |
| 1792 | minIndex=i; |
| 1793 | } |
| 1794 | return mSurvivors[minIndex]; |
| 1795 | } |
| 1796 | |
| 1797 | |
| 1798 | const ViterbiTCH_AFS4_75::vCand& ViterbiTCH_AFS4_75::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 1799 | { |
| 1800 | branchCandidates(); |
| 1801 | getSoftCostMetrics(inSample,probs,iprobs); |
| 1802 | pruneCandidates(); |
| 1803 | return minCost(); |
| 1804 | } |
| 1805 | |
| 1806 | |
| 1807 | |
| 1808 | void ViterbiTCH_AFS4_75::decode(const SoftVector &in, BitVector& target) |
| 1809 | { |
| 1810 | ViterbiTCH_AFS4_75 &decoder = *this; |
| 1811 | const size_t sz = in.size() - 30; |
| 1812 | const unsigned deferral = decoder.deferral(); |
| 1813 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 1814 | assert(sz == decoder.iRate()*target.size()); |
| 1815 | |
| 1816 | // Build a "history" array where each element contains the full history. |
| 1817 | uint32_t history[ctsz]; |
| 1818 | { |
| 1819 | BitVector bits = in.sliced(); |
| 1820 | uint32_t accum = 0; |
| 1821 | for (size_t i=0; i<sz; i++) { |
| 1822 | accum = (accum<<1) | bits.bit(i); |
| 1823 | history[i] = accum; |
| 1824 | } |
| 1825 | // Repeat last bit at the end. |
| 1826 | for (size_t i=sz; i<ctsz; i++) { |
| 1827 | accum = (accum<<1) | (accum & 0x01); |
| 1828 | history[i] = accum; |
| 1829 | } |
| 1830 | } |
| 1831 | |
| 1832 | // Precompute metric tables. |
| 1833 | float matchCostTable[ctsz]; |
| 1834 | float mismatchCostTable[ctsz]; |
| 1835 | { |
| 1836 | const float *dp = in.begin(); |
| 1837 | for (size_t i=0; i<sz; i++) { |
| 1838 | // pVal is the probability that a bit is correct. |
| 1839 | // ipVal is the probability that a bit is incorrect. |
| 1840 | float pVal = dp[i]; |
| 1841 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1842 | float ipVal = 1.0F-pVal; |
| 1843 | // This is a cheap approximation to an ideal cost function. |
| 1844 | if (pVal<0.01F) pVal = 0.01; |
| 1845 | if (ipVal<0.01F) ipVal = 0.01; |
| 1846 | matchCostTable[i] = 0.25F/ipVal; |
| 1847 | mismatchCostTable[i] = 0.25F/pVal; |
| 1848 | } |
| 1849 | |
| 1850 | // pad end of table with unknowns |
| 1851 | for (size_t i=sz; i<ctsz; i++) { |
| 1852 | matchCostTable[i] = 0.5F; |
| 1853 | mismatchCostTable[i] = 0.5F; |
| 1854 | } |
| 1855 | } |
| 1856 | |
| 1857 | { |
| 1858 | decoder.initializeStates(); |
| 1859 | // Each sample of history[] carries its history. |
| 1860 | // So we only have to process every iRate-th sample. |
| 1861 | const unsigned step = decoder.iRate(); |
| 1862 | // input pointer |
| 1863 | const uint32_t *ip = history + step - 1; |
| 1864 | // output pointers |
| 1865 | char *op = target.begin(); |
| 1866 | const char *const opt = target.end(); |
| 1867 | // table pointers |
| 1868 | const float* match = matchCostTable; |
| 1869 | const float* mismatch = mismatchCostTable; |
| 1870 | size_t oCount = 0; |
| 1871 | while (op<opt) { |
| 1872 | // Viterbi algorithm |
| 1873 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1874 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1875 | const ViterbiTCH_AFS4_75::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1876 | ip += step; |
| 1877 | match += step; |
| 1878 | mismatch += step; |
| 1879 | // output |
| 1880 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1881 | oCount++; |
| 1882 | } |
| 1883 | } |
| 1884 | } |
| 1885 | |
| 1886 | |
| 1887 | |