Roman Khassraf | d38206c | 2015-06-07 16:26:29 +0200 | [diff] [blame] | 1 | /* |
Piotr Krysik | b9a87a1 | 2017-08-23 15:59:28 +0200 | [diff] [blame] | 2 | * Copyright 2013, 2014 Range Networks, Inc. |
| 3 | * |
| 4 | * This program is free software: you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU Affero General Public License as published by |
| 6 | * the Free Software Foundation, either version 3 of the License, or |
| 7 | * (at your option) any later version. |
Roman Khassraf | d38206c | 2015-06-07 16:26:29 +0200 | [diff] [blame] | 8 | |
Piotr Krysik | b9a87a1 | 2017-08-23 15:59:28 +0200 | [diff] [blame] | 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU Affero General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Affero General Public License |
| 15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | * |
| 17 | * This use of this software may be subject to additional restrictions. |
| 18 | * See the LEGAL file in the main directory for details. |
| 19 | */ |
Roman Khassraf | d38206c | 2015-06-07 16:26:29 +0200 | [diff] [blame] | 20 | |
| 21 | |
| 22 | #include "BitVector.h" |
| 23 | #include "AmrCoder.h" |
| 24 | #include <iostream> |
| 25 | #include <stdio.h> |
| 26 | #include <sstream> |
| 27 | |
| 28 | using namespace std; |
| 29 | |
| 30 | |
| 31 | |
| 32 | ViterbiTCH_AFS12_2::ViterbiTCH_AFS12_2() |
| 33 | { |
| 34 | assert(mDeferral < 32); |
| 35 | mCoeffs[0] = 0x019; |
| 36 | mCoeffsFB[0] = 0x019; |
| 37 | mCoeffs[1] = 0x01b; |
| 38 | mCoeffsFB[1] = 0x019; |
| 39 | for (unsigned i = 0; i < mIRate; i++) { |
| 40 | computeStateTables(i); |
| 41 | } |
| 42 | computeGeneratorTable(); |
| 43 | } |
| 44 | |
| 45 | |
| 46 | //void BitVector::encode(const ViterbiTCH_AFS12_2& coder, BitVector& target) const |
| 47 | void ViterbiTCH_AFS12_2::encode(const BitVector& in, BitVector& target) const |
| 48 | { |
| 49 | assert(in.size() == 250); |
| 50 | assert(target.size() == 508); |
| 51 | const char *u = in.begin(); |
| 52 | char *C = target.begin(); |
| 53 | const unsigned H = 4; |
| 54 | BitVector r(254+H); |
| 55 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 56 | for (unsigned k = 0; k <= 249; k++) { |
| 57 | r[k+H] = u[k] ^ r[k-3+H] ^ r[k-4+H]; |
| 58 | C[2*k] = u[k]; |
| 59 | C[2*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 60 | } |
| 61 | // termination |
| 62 | for (unsigned k = 250; k <= 253; k++) { |
| 63 | r[k+H] = 0; |
| 64 | C[2*k] = r[k-3+H] ^ r[k-4+H]; |
| 65 | C[2*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | |
| 70 | |
| 71 | //void BitVector::encode(const ViterbiTCH_AFS10_2& coder, BitVector& target) |
| 72 | void ViterbiTCH_AFS10_2::encode(const BitVector& in, BitVector& target) const |
| 73 | { |
| 74 | assert(in.size() == 210); |
| 75 | assert(target.size() == 642); |
| 76 | const char *u = in.begin(); |
| 77 | char *C = target.begin(); |
| 78 | const unsigned H = 4; |
| 79 | BitVector r(214+H); |
| 80 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 81 | for (unsigned k = 0; k <= 209; k++) { |
| 82 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 83 | C[3*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 84 | C[3*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 85 | C[3*k+2] = u[k]; |
| 86 | } |
| 87 | // termination |
| 88 | for (unsigned k = 210; k <= 213; k++) { |
| 89 | r[k+H] = 0; |
| 90 | C[3*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 91 | C[3*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 92 | C[3*k+2] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | |
| 97 | |
| 98 | //void BitVector::encode(const ViterbiTCH_AFS7_95& coder, BitVector& target) |
| 99 | void ViterbiTCH_AFS7_95::encode(const BitVector& in, BitVector& target) const |
| 100 | { |
| 101 | assert(in.size() == 165); |
| 102 | assert(target.size() == 513); |
| 103 | const char *u = in.begin(); |
| 104 | char *C = target.begin(); |
| 105 | const unsigned H = 6; |
| 106 | BitVector r(171+H); |
| 107 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 108 | for (unsigned k = 0; k <= 164; k++) { |
| 109 | r[k+H] = u[k] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 110 | C[3*k] = u[k]; |
| 111 | C[3*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 112 | 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]; |
| 113 | } |
| 114 | // termination |
| 115 | for (unsigned k = 165; k <= 170; k++) { |
| 116 | r[k+H] = 0; |
| 117 | C[3*k] = r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 118 | C[3*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 119 | 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]; |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | |
| 124 | |
| 125 | void ViterbiTCH_AFS7_4::encode(const BitVector& in, BitVector& target) const |
| 126 | { |
| 127 | assert(in.size() == 154); |
| 128 | assert(target.size() == 474); |
| 129 | const char *u = in.begin(); |
| 130 | char *C = target.begin(); |
| 131 | const unsigned H = 4; |
| 132 | BitVector r(158+H); |
| 133 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 134 | for (unsigned k = 0; k <= 153; k++) { |
| 135 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 136 | C[3*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 137 | C[3*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 138 | C[3*k+2] = u[k]; |
| 139 | } |
| 140 | // termination |
| 141 | for (unsigned k = 154; k <= 157; k++) { |
| 142 | r[k+H] = 0; |
| 143 | C[3*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 144 | C[3*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 145 | C[3*k+2] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | |
| 150 | |
| 151 | void ViterbiTCH_AFS6_7::encode(const BitVector& in, BitVector& target) const |
| 152 | { |
| 153 | assert(in.size() == 140); |
| 154 | assert(target.size() == 576); |
| 155 | const char *u = in.begin(); |
| 156 | char *C = target.begin(); |
| 157 | const unsigned H = 4; |
| 158 | BitVector r(144+H); |
| 159 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 160 | for (unsigned k = 0; k <= 139; k++) { |
| 161 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 162 | C[4*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 163 | C[4*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 164 | C[4*k+2] = u[k]; |
| 165 | C[4*k+3] = u[k]; |
| 166 | } |
| 167 | // termination |
| 168 | for (unsigned k = 140; k <= 143; k++) { |
| 169 | r[k+H] = 0; |
| 170 | C[4*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 171 | C[4*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 172 | C[4*k+2] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 173 | C[4*k+3] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | |
| 178 | |
| 179 | void ViterbiTCH_AFS5_9::encode(const BitVector& in, BitVector& target) const |
| 180 | { |
| 181 | assert(in.size() == 124); |
| 182 | assert(target.size() == 520); |
| 183 | const char *u = in.begin(); |
| 184 | char *C = target.begin(); |
| 185 | const unsigned H = 6; |
| 186 | BitVector r(130+H); |
| 187 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 188 | for (unsigned k = 0; k <= 123; k++) { |
| 189 | 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]; |
| 190 | C[4*k] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 191 | C[4*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 192 | C[4*k+2] = u[k]; |
| 193 | C[4*k+3] = u[k]; |
| 194 | } |
| 195 | // termination |
| 196 | for (unsigned k = 124; k <= 129; k++) { |
| 197 | r[k+H] = 0; |
| 198 | C[4*k] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 199 | C[4*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 200 | C[4*k+2] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 201 | C[4*k+3] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | |
| 206 | |
| 207 | void ViterbiTCH_AFS5_15::encode(const BitVector& in, BitVector& target) const |
| 208 | { |
| 209 | assert(in.size() == 109); |
| 210 | assert(target.size() == 565); |
| 211 | const char *u = in.begin(); |
| 212 | char *C = target.begin(); |
| 213 | const unsigned H = 4; |
| 214 | BitVector r(113+H); |
| 215 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 216 | for (unsigned k = 0; k <= 108; k++) { |
| 217 | r[k+H] = u[k] ^ r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 218 | C[5*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 219 | C[5*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 220 | C[5*k+2] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 221 | C[5*k+3] = u[k]; |
| 222 | C[5*k+4] = u[k]; |
| 223 | } |
| 224 | // termination |
| 225 | for (unsigned k = 109; k <= 112; k++) { |
| 226 | r[k+H] = 0; |
| 227 | C[5*k] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 228 | C[5*k+1] = r[k+H] ^ r[k-1+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 229 | C[5*k+2] = r[k+H] ^ r[k-2+H] ^ r[k-4+H]; |
| 230 | C[5*k+3] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 231 | C[5*k+4] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H]; |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | |
| 236 | |
| 237 | void ViterbiTCH_AFS4_75::encode(const BitVector& in, BitVector& target) const |
| 238 | { |
| 239 | assert(in.size() == 101); |
| 240 | assert(target.size() == 535); |
| 241 | const char *u = in.begin(); |
| 242 | char *C = target.begin(); |
| 243 | const unsigned H = 6; |
| 244 | BitVector r(107+H); |
| 245 | for (int k = -H; k <= -1; k++) r[k+H] = 0; |
| 246 | for (unsigned k = 0; k <= 100; k++) { |
| 247 | 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]; |
| 248 | C[5*k] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 249 | C[5*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 250 | C[5*k+2] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 251 | C[5*k+3] = u[k]; |
| 252 | C[5*k+4] = u[k]; |
| 253 | } |
| 254 | // termination |
| 255 | for (unsigned k = 101; k <= 106; k++) { |
| 256 | r[k+H] = 0; |
| 257 | C[5*k] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 258 | C[5*k+1] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-5+H] ^ r[k-6+H]; |
| 259 | C[5*k+2] = r[k+H] ^ r[k-1+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 260 | C[5*k+3] = r[k+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 261 | C[5*k+4] = r[k-1+H] ^ r[k-2+H] ^ r[k-3+H] ^ r[k-4+H] ^ r[k-6+H]; |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | |
| 266 | void ViterbiTCH_AFS12_2::initializeStates() |
| 267 | { |
| 268 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 269 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 270 | } |
| 271 | |
| 272 | |
| 273 | |
| 274 | void ViterbiTCH_AFS12_2::computeStateTables(unsigned g) |
| 275 | { |
| 276 | assert(g<mIRate); |
| 277 | for (unsigned state=0; state<mIStates; state++) { |
| 278 | for (unsigned in = 0; in <= 1; in++) { |
| 279 | uint32_t inputVal = (state<<1) | in; |
| 280 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 281 | } |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | void ViterbiTCH_AFS12_2::computeGeneratorTable() |
| 286 | { |
| 287 | for (unsigned index=0; index<mIStates*2; index++) { |
| 288 | uint32_t t = 0; |
| 289 | for (unsigned i = 0; i < mIRate; i++) { |
| 290 | t = (t << 1) | mStateTable[i][index]; |
| 291 | } |
| 292 | mGeneratorTable[index] = t; |
| 293 | } |
| 294 | } |
| 295 | |
| 296 | |
| 297 | |
| 298 | |
| 299 | |
| 300 | |
| 301 | void ViterbiTCH_AFS12_2::branchCandidates() |
| 302 | { |
| 303 | // Branch to generate new input states. |
| 304 | const vCand *sp = mSurvivors; |
| 305 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 306 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 307 | for (unsigned in = 0; in <= 1; in++) { |
| 308 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 309 | mCandidates[cand+in].cost = sp->cost; |
| 310 | uint32_t outputs = oStateShifted; |
| 311 | for (unsigned out = 0; out < mIRate; out++) { |
| 312 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 313 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 314 | mCandidates[cand+in].rState[out] = rState; |
| 315 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 316 | } |
| 317 | mCandidates[cand+in].oState = outputs; |
| 318 | } |
| 319 | sp++; |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | |
| 324 | void ViterbiTCH_AFS12_2::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 325 | { |
| 326 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 327 | for (unsigned i=0; i<mNumCands; i++) { |
| 328 | vCand& thisCand = mCandidates[i]; |
| 329 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 330 | for (unsigned i = 0; i < mIRate; i++) { |
| 331 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 332 | } |
| 333 | } |
| 334 | } |
| 335 | |
| 336 | |
| 337 | void ViterbiTCH_AFS12_2::pruneCandidates() |
| 338 | { |
| 339 | const vCand* c1 = mCandidates; // 0-prefix |
| 340 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 341 | for (unsigned i=0; i<mIStates; i++) { |
| 342 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 343 | else mSurvivors[i] = c2[i]; |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | |
| 348 | const ViterbiTCH_AFS12_2::vCand& ViterbiTCH_AFS12_2::minCost() const |
| 349 | { |
| 350 | int minIndex = 0; |
| 351 | float minCost = mSurvivors[0].cost; |
| 352 | for (unsigned i=1; i<mIStates; i++) { |
| 353 | const float thisCost = mSurvivors[i].cost; |
| 354 | if (thisCost>=minCost) continue; |
| 355 | minCost = thisCost; |
| 356 | minIndex=i; |
| 357 | } |
| 358 | return mSurvivors[minIndex]; |
| 359 | } |
| 360 | |
| 361 | |
| 362 | const ViterbiTCH_AFS12_2::vCand& ViterbiTCH_AFS12_2::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 363 | { |
| 364 | branchCandidates(); |
| 365 | getSoftCostMetrics(inSample,probs,iprobs); |
| 366 | pruneCandidates(); |
| 367 | return minCost(); |
| 368 | } |
| 369 | |
| 370 | |
| 371 | |
| 372 | void ViterbiTCH_AFS12_2::decode(const SoftVector &in, BitVector& target) |
| 373 | { |
| 374 | ViterbiTCH_AFS12_2 &decoder = *this; |
| 375 | const size_t sz = in.size() - 8; |
| 376 | const unsigned deferral = decoder.deferral(); |
| 377 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 378 | assert(sz == decoder.iRate()*target.size()); |
| 379 | |
| 380 | // Build a "history" array where each element contains the full history. |
| 381 | uint32_t history[ctsz]; |
| 382 | { |
| 383 | BitVector bits = in.sliced(); |
| 384 | uint32_t accum = 0; |
| 385 | for (size_t i=0; i<sz; i++) { |
| 386 | accum = (accum<<1) | bits.bit(i); |
| 387 | history[i] = accum; |
| 388 | } |
| 389 | // Repeat last bit at the end. |
| 390 | for (size_t i=sz; i<ctsz; i++) { |
| 391 | accum = (accum<<1) | (accum & 0x01); |
| 392 | history[i] = accum; |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | // Precompute metric tables. |
| 397 | float matchCostTable[ctsz]; |
| 398 | float mismatchCostTable[ctsz]; |
| 399 | { |
| 400 | const float *dp = in.begin(); |
| 401 | for (size_t i=0; i<sz; i++) { |
| 402 | // pVal is the probability that a bit is correct. |
| 403 | // ipVal is the probability that a bit is incorrect. |
| 404 | float pVal = dp[i]; |
| 405 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 406 | float ipVal = 1.0F-pVal; |
| 407 | // This is a cheap approximation to an ideal cost function. |
| 408 | if (pVal<0.01F) pVal = 0.01; |
| 409 | if (ipVal<0.01F) ipVal = 0.01; |
| 410 | matchCostTable[i] = 0.25F/ipVal; |
| 411 | mismatchCostTable[i] = 0.25F/pVal; |
| 412 | } |
| 413 | |
| 414 | // pad end of table with unknowns |
| 415 | for (size_t i=sz; i<ctsz; i++) { |
| 416 | matchCostTable[i] = 0.5F; |
| 417 | mismatchCostTable[i] = 0.5F; |
| 418 | } |
| 419 | } |
| 420 | |
| 421 | { |
| 422 | decoder.initializeStates(); |
| 423 | // Each sample of history[] carries its history. |
| 424 | // So we only have to process every iRate-th sample. |
| 425 | const unsigned step = decoder.iRate(); |
| 426 | // input pointer |
| 427 | const uint32_t *ip = history + step - 1; |
| 428 | // output pointers |
| 429 | char *op = target.begin(); |
| 430 | const char *const opt = target.end(); |
| 431 | // table pointers |
| 432 | const float* match = matchCostTable; |
| 433 | const float* mismatch = mismatchCostTable; |
| 434 | size_t oCount = 0; |
| 435 | while (op<opt) { |
| 436 | // Viterbi algorithm |
| 437 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 438 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 439 | const ViterbiTCH_AFS12_2::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 440 | ip += step; |
| 441 | match += step; |
| 442 | mismatch += step; |
| 443 | // output |
| 444 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 445 | oCount++; |
| 446 | } |
| 447 | } |
| 448 | } |
| 449 | |
| 450 | |
| 451 | |
| 452 | ViterbiTCH_AFS10_2::ViterbiTCH_AFS10_2() |
| 453 | { |
| 454 | assert(mDeferral < 32); |
| 455 | mCoeffs[0] = 0x01b; |
| 456 | mCoeffsFB[0] = 0x01f; |
| 457 | mCoeffs[1] = 0x015; |
| 458 | mCoeffsFB[1] = 0x01f; |
| 459 | mCoeffs[2] = 0x01f; |
| 460 | mCoeffsFB[2] = 0x01f; |
| 461 | for (unsigned i = 0; i < mIRate; i++) { |
| 462 | computeStateTables(i); |
| 463 | } |
| 464 | computeGeneratorTable(); |
| 465 | } |
| 466 | |
| 467 | |
| 468 | |
| 469 | |
| 470 | void ViterbiTCH_AFS10_2::initializeStates() |
| 471 | { |
| 472 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 473 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 474 | } |
| 475 | |
| 476 | |
| 477 | |
| 478 | void ViterbiTCH_AFS10_2::computeStateTables(unsigned g) |
| 479 | { |
| 480 | assert(g<mIRate); |
| 481 | for (unsigned state=0; state<mIStates; state++) { |
| 482 | for (unsigned in = 0; in <= 1; in++) { |
| 483 | uint32_t inputVal = (state<<1) | in; |
| 484 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 485 | } |
| 486 | } |
| 487 | } |
| 488 | |
| 489 | void ViterbiTCH_AFS10_2::computeGeneratorTable() |
| 490 | { |
| 491 | for (unsigned index=0; index<mIStates*2; index++) { |
| 492 | uint32_t t = 0; |
| 493 | for (unsigned i = 0; i < mIRate; i++) { |
| 494 | t = (t << 1) | mStateTable[i][index]; |
| 495 | } |
| 496 | mGeneratorTable[index] = t; |
| 497 | } |
| 498 | } |
| 499 | |
| 500 | |
| 501 | |
| 502 | |
| 503 | |
| 504 | |
| 505 | void ViterbiTCH_AFS10_2::branchCandidates() |
| 506 | { |
| 507 | // Branch to generate new input states. |
| 508 | const vCand *sp = mSurvivors; |
| 509 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 510 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 511 | for (unsigned in = 0; in <= 1; in++) { |
| 512 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 513 | mCandidates[cand+in].cost = sp->cost; |
| 514 | uint32_t outputs = oStateShifted; |
| 515 | for (unsigned out = 0; out < mIRate; out++) { |
| 516 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 517 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 518 | mCandidates[cand+in].rState[out] = rState; |
| 519 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 520 | } |
| 521 | mCandidates[cand+in].oState = outputs; |
| 522 | } |
| 523 | sp++; |
| 524 | } |
| 525 | } |
| 526 | |
| 527 | |
| 528 | void ViterbiTCH_AFS10_2::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 529 | { |
| 530 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 531 | for (unsigned i=0; i<mNumCands; i++) { |
| 532 | vCand& thisCand = mCandidates[i]; |
| 533 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 534 | for (unsigned i = 0; i < mIRate; i++) { |
| 535 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 536 | } |
| 537 | } |
| 538 | } |
| 539 | |
| 540 | |
| 541 | void ViterbiTCH_AFS10_2::pruneCandidates() |
| 542 | { |
| 543 | const vCand* c1 = mCandidates; // 0-prefix |
| 544 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 545 | for (unsigned i=0; i<mIStates; i++) { |
| 546 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 547 | else mSurvivors[i] = c2[i]; |
| 548 | } |
| 549 | } |
| 550 | |
| 551 | |
| 552 | const ViterbiTCH_AFS10_2::vCand& ViterbiTCH_AFS10_2::minCost() const |
| 553 | { |
| 554 | int minIndex = 0; |
| 555 | float minCost = mSurvivors[0].cost; |
| 556 | for (unsigned i=1; i<mIStates; i++) { |
| 557 | const float thisCost = mSurvivors[i].cost; |
| 558 | if (thisCost>=minCost) continue; |
| 559 | minCost = thisCost; |
| 560 | minIndex=i; |
| 561 | } |
| 562 | return mSurvivors[minIndex]; |
| 563 | } |
| 564 | |
| 565 | |
| 566 | const ViterbiTCH_AFS10_2::vCand& ViterbiTCH_AFS10_2::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 567 | { |
| 568 | branchCandidates(); |
| 569 | getSoftCostMetrics(inSample,probs,iprobs); |
| 570 | pruneCandidates(); |
| 571 | return minCost(); |
| 572 | } |
| 573 | |
| 574 | |
| 575 | |
| 576 | void ViterbiTCH_AFS10_2::decode(const SoftVector &in, BitVector& target) |
| 577 | { |
| 578 | ViterbiTCH_AFS10_2 &decoder = *this; |
| 579 | const size_t sz = in.size() - 12; |
| 580 | const unsigned deferral = decoder.deferral(); |
| 581 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 582 | assert(sz == decoder.iRate()*target.size()); |
| 583 | |
| 584 | // Build a "history" array where each element contains the full history. |
| 585 | uint32_t history[ctsz]; |
| 586 | { |
| 587 | BitVector bits = in.sliced(); |
| 588 | uint32_t accum = 0; |
| 589 | for (size_t i=0; i<sz; i++) { |
| 590 | accum = (accum<<1) | bits.bit(i); |
| 591 | history[i] = accum; |
| 592 | } |
| 593 | // Repeat last bit at the end. |
| 594 | for (size_t i=sz; i<ctsz; i++) { |
| 595 | accum = (accum<<1) | (accum & 0x01); |
| 596 | history[i] = accum; |
| 597 | } |
| 598 | } |
| 599 | |
| 600 | // Precompute metric tables. |
| 601 | float matchCostTable[ctsz]; |
| 602 | float mismatchCostTable[ctsz]; |
| 603 | { |
| 604 | const float *dp = in.begin(); |
| 605 | for (size_t i=0; i<sz; i++) { |
| 606 | // pVal is the probability that a bit is correct. |
| 607 | // ipVal is the probability that a bit is incorrect. |
| 608 | float pVal = dp[i]; |
| 609 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 610 | float ipVal = 1.0F-pVal; |
| 611 | // This is a cheap approximation to an ideal cost function. |
| 612 | if (pVal<0.01F) pVal = 0.01; |
| 613 | if (ipVal<0.01F) ipVal = 0.01; |
| 614 | matchCostTable[i] = 0.25F/ipVal; |
| 615 | mismatchCostTable[i] = 0.25F/pVal; |
| 616 | } |
| 617 | |
| 618 | // pad end of table with unknowns |
| 619 | for (size_t i=sz; i<ctsz; i++) { |
| 620 | matchCostTable[i] = 0.5F; |
| 621 | mismatchCostTable[i] = 0.5F; |
| 622 | } |
| 623 | } |
| 624 | |
| 625 | { |
| 626 | decoder.initializeStates(); |
| 627 | // Each sample of history[] carries its history. |
| 628 | // So we only have to process every iRate-th sample. |
| 629 | const unsigned step = decoder.iRate(); |
| 630 | // input pointer |
| 631 | const uint32_t *ip = history + step - 1; |
| 632 | // output pointers |
| 633 | char *op = target.begin(); |
| 634 | const char *const opt = target.end(); |
| 635 | // table pointers |
| 636 | const float* match = matchCostTable; |
| 637 | const float* mismatch = mismatchCostTable; |
| 638 | size_t oCount = 0; |
| 639 | while (op<opt) { |
| 640 | // Viterbi algorithm |
| 641 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 642 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 643 | const ViterbiTCH_AFS10_2::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 644 | ip += step; |
| 645 | match += step; |
| 646 | mismatch += step; |
| 647 | // output |
| 648 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 649 | oCount++; |
| 650 | } |
| 651 | } |
| 652 | } |
| 653 | |
| 654 | |
| 655 | |
| 656 | ViterbiTCH_AFS7_95::ViterbiTCH_AFS7_95() |
| 657 | { |
| 658 | assert(mDeferral < 32); |
| 659 | mCoeffs[0] = 0x06d; |
| 660 | mCoeffsFB[0] = 0x06d; |
| 661 | mCoeffs[1] = 0x053; |
| 662 | mCoeffsFB[1] = 0x06d; |
| 663 | mCoeffs[2] = 0x05f; |
| 664 | mCoeffsFB[2] = 0x06d; |
| 665 | for (unsigned i = 0; i < mIRate; i++) { |
| 666 | computeStateTables(i); |
| 667 | } |
| 668 | computeGeneratorTable(); |
| 669 | } |
| 670 | |
| 671 | |
| 672 | |
| 673 | |
| 674 | void ViterbiTCH_AFS7_95::initializeStates() |
| 675 | { |
| 676 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 677 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 678 | } |
| 679 | |
| 680 | |
| 681 | |
| 682 | void ViterbiTCH_AFS7_95::computeStateTables(unsigned g) |
| 683 | { |
| 684 | assert(g<mIRate); |
| 685 | for (unsigned state=0; state<mIStates; state++) { |
| 686 | for (unsigned in = 0; in <= 1; in++) { |
| 687 | uint32_t inputVal = (state<<1) | in; |
| 688 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 689 | } |
| 690 | } |
| 691 | } |
| 692 | |
| 693 | void ViterbiTCH_AFS7_95::computeGeneratorTable() |
| 694 | { |
| 695 | for (unsigned index=0; index<mIStates*2; index++) { |
| 696 | uint32_t t = 0; |
| 697 | for (unsigned i = 0; i < mIRate; i++) { |
| 698 | t = (t << 1) | mStateTable[i][index]; |
| 699 | } |
| 700 | mGeneratorTable[index] = t; |
| 701 | } |
| 702 | } |
| 703 | |
| 704 | |
| 705 | |
| 706 | |
| 707 | |
| 708 | |
| 709 | void ViterbiTCH_AFS7_95::branchCandidates() |
| 710 | { |
| 711 | // Branch to generate new input states. |
| 712 | const vCand *sp = mSurvivors; |
| 713 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 714 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 715 | for (unsigned in = 0; in <= 1; in++) { |
| 716 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 717 | mCandidates[cand+in].cost = sp->cost; |
| 718 | uint32_t outputs = oStateShifted; |
| 719 | for (unsigned out = 0; out < mIRate; out++) { |
| 720 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 721 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 722 | mCandidates[cand+in].rState[out] = rState; |
| 723 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 724 | } |
| 725 | mCandidates[cand+in].oState = outputs; |
| 726 | } |
| 727 | sp++; |
| 728 | } |
| 729 | } |
| 730 | |
| 731 | |
| 732 | void ViterbiTCH_AFS7_95::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 733 | { |
| 734 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 735 | for (unsigned i=0; i<mNumCands; i++) { |
| 736 | vCand& thisCand = mCandidates[i]; |
| 737 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 738 | for (unsigned i = 0; i < mIRate; i++) { |
| 739 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 740 | } |
| 741 | } |
| 742 | } |
| 743 | |
| 744 | |
| 745 | void ViterbiTCH_AFS7_95::pruneCandidates() |
| 746 | { |
| 747 | const vCand* c1 = mCandidates; // 0-prefix |
| 748 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 749 | for (unsigned i=0; i<mIStates; i++) { |
| 750 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 751 | else mSurvivors[i] = c2[i]; |
| 752 | } |
| 753 | } |
| 754 | |
| 755 | |
| 756 | const ViterbiTCH_AFS7_95::vCand& ViterbiTCH_AFS7_95::minCost() const |
| 757 | { |
| 758 | int minIndex = 0; |
| 759 | float minCost = mSurvivors[0].cost; |
| 760 | for (unsigned i=1; i<mIStates; i++) { |
| 761 | const float thisCost = mSurvivors[i].cost; |
| 762 | if (thisCost>=minCost) continue; |
| 763 | minCost = thisCost; |
| 764 | minIndex=i; |
| 765 | } |
| 766 | return mSurvivors[minIndex]; |
| 767 | } |
| 768 | |
| 769 | |
| 770 | const ViterbiTCH_AFS7_95::vCand& ViterbiTCH_AFS7_95::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 771 | { |
| 772 | branchCandidates(); |
| 773 | getSoftCostMetrics(inSample,probs,iprobs); |
| 774 | pruneCandidates(); |
| 775 | return minCost(); |
| 776 | } |
| 777 | |
| 778 | |
| 779 | |
| 780 | void ViterbiTCH_AFS7_95::decode(const SoftVector &in, BitVector& target) |
| 781 | { |
| 782 | ViterbiTCH_AFS7_95 &decoder = *this; |
| 783 | const size_t sz = in.size() - 18; |
| 784 | const unsigned deferral = decoder.deferral(); |
| 785 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 786 | assert(sz == decoder.iRate()*target.size()); |
| 787 | |
| 788 | // Build a "history" array where each element contains the full history. |
| 789 | uint32_t history[ctsz]; |
| 790 | { |
| 791 | BitVector bits = in.sliced(); |
| 792 | uint32_t accum = 0; |
| 793 | for (size_t i=0; i<sz; i++) { |
| 794 | accum = (accum<<1) | bits.bit(i); |
| 795 | history[i] = accum; |
| 796 | } |
| 797 | // Repeat last bit at the end. |
| 798 | for (size_t i=sz; i<ctsz; i++) { |
| 799 | accum = (accum<<1) | (accum & 0x01); |
| 800 | history[i] = accum; |
| 801 | } |
| 802 | } |
| 803 | |
| 804 | // Precompute metric tables. |
| 805 | float matchCostTable[ctsz]; |
| 806 | float mismatchCostTable[ctsz]; |
| 807 | { |
| 808 | const float *dp = in.begin(); |
| 809 | for (size_t i=0; i<sz; i++) { |
| 810 | // pVal is the probability that a bit is correct. |
| 811 | // ipVal is the probability that a bit is incorrect. |
| 812 | float pVal = dp[i]; |
| 813 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 814 | float ipVal = 1.0F-pVal; |
| 815 | // This is a cheap approximation to an ideal cost function. |
| 816 | if (pVal<0.01F) pVal = 0.01; |
| 817 | if (ipVal<0.01F) ipVal = 0.01; |
| 818 | matchCostTable[i] = 0.25F/ipVal; |
| 819 | mismatchCostTable[i] = 0.25F/pVal; |
| 820 | } |
| 821 | |
| 822 | // pad end of table with unknowns |
| 823 | for (size_t i=sz; i<ctsz; i++) { |
| 824 | matchCostTable[i] = 0.5F; |
| 825 | mismatchCostTable[i] = 0.5F; |
| 826 | } |
| 827 | } |
| 828 | |
| 829 | { |
| 830 | decoder.initializeStates(); |
| 831 | // Each sample of history[] carries its history. |
| 832 | // So we only have to process every iRate-th sample. |
| 833 | const unsigned step = decoder.iRate(); |
| 834 | // input pointer |
| 835 | const uint32_t *ip = history + step - 1; |
| 836 | // output pointers |
| 837 | char *op = target.begin(); |
| 838 | const char *const opt = target.end(); |
| 839 | // table pointers |
| 840 | const float* match = matchCostTable; |
| 841 | const float* mismatch = mismatchCostTable; |
| 842 | size_t oCount = 0; |
| 843 | while (op<opt) { |
| 844 | // Viterbi algorithm |
| 845 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 846 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 847 | const ViterbiTCH_AFS7_95::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 848 | ip += step; |
| 849 | match += step; |
| 850 | mismatch += step; |
| 851 | // output |
| 852 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 853 | oCount++; |
| 854 | } |
| 855 | } |
| 856 | } |
| 857 | |
| 858 | |
| 859 | |
| 860 | ViterbiTCH_AFS7_4::ViterbiTCH_AFS7_4() |
| 861 | { |
| 862 | assert(mDeferral < 32); |
| 863 | mCoeffs[0] = 0x01b; |
| 864 | mCoeffsFB[0] = 0x01f; |
| 865 | mCoeffs[1] = 0x015; |
| 866 | mCoeffsFB[1] = 0x01f; |
| 867 | mCoeffs[2] = 0x01f; |
| 868 | mCoeffsFB[2] = 0x01f; |
| 869 | for (unsigned i = 0; i < mIRate; i++) { |
| 870 | computeStateTables(i); |
| 871 | } |
| 872 | computeGeneratorTable(); |
| 873 | } |
| 874 | |
| 875 | |
| 876 | |
| 877 | |
| 878 | void ViterbiTCH_AFS7_4::initializeStates() |
| 879 | { |
| 880 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 881 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 882 | } |
| 883 | |
| 884 | |
| 885 | |
| 886 | void ViterbiTCH_AFS7_4::computeStateTables(unsigned g) |
| 887 | { |
| 888 | assert(g<mIRate); |
| 889 | for (unsigned state=0; state<mIStates; state++) { |
| 890 | for (unsigned in = 0; in <= 1; in++) { |
| 891 | uint32_t inputVal = (state<<1) | in; |
| 892 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 893 | } |
| 894 | } |
| 895 | } |
| 896 | |
| 897 | void ViterbiTCH_AFS7_4::computeGeneratorTable() |
| 898 | { |
| 899 | for (unsigned index=0; index<mIStates*2; index++) { |
| 900 | uint32_t t = 0; |
| 901 | for (unsigned i = 0; i < mIRate; i++) { |
| 902 | t = (t << 1) | mStateTable[i][index]; |
| 903 | } |
| 904 | mGeneratorTable[index] = t; |
| 905 | } |
| 906 | } |
| 907 | |
| 908 | |
| 909 | |
| 910 | |
| 911 | |
| 912 | |
| 913 | void ViterbiTCH_AFS7_4::branchCandidates() |
| 914 | { |
| 915 | // Branch to generate new input states. |
| 916 | const vCand *sp = mSurvivors; |
| 917 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 918 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 919 | for (unsigned in = 0; in <= 1; in++) { |
| 920 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 921 | mCandidates[cand+in].cost = sp->cost; |
| 922 | uint32_t outputs = oStateShifted; |
| 923 | for (unsigned out = 0; out < mIRate; out++) { |
| 924 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 925 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 926 | mCandidates[cand+in].rState[out] = rState; |
| 927 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 928 | } |
| 929 | mCandidates[cand+in].oState = outputs; |
| 930 | } |
| 931 | sp++; |
| 932 | } |
| 933 | } |
| 934 | |
| 935 | |
| 936 | void ViterbiTCH_AFS7_4::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 937 | { |
| 938 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 939 | for (unsigned i=0; i<mNumCands; i++) { |
| 940 | vCand& thisCand = mCandidates[i]; |
| 941 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 942 | for (unsigned i = 0; i < mIRate; i++) { |
| 943 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 944 | } |
| 945 | } |
| 946 | } |
| 947 | |
| 948 | |
| 949 | void ViterbiTCH_AFS7_4::pruneCandidates() |
| 950 | { |
| 951 | const vCand* c1 = mCandidates; // 0-prefix |
| 952 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 953 | for (unsigned i=0; i<mIStates; i++) { |
| 954 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 955 | else mSurvivors[i] = c2[i]; |
| 956 | } |
| 957 | } |
| 958 | |
| 959 | |
| 960 | const ViterbiTCH_AFS7_4::vCand& ViterbiTCH_AFS7_4::minCost() const |
| 961 | { |
| 962 | int minIndex = 0; |
| 963 | float minCost = mSurvivors[0].cost; |
| 964 | for (unsigned i=1; i<mIStates; i++) { |
| 965 | const float thisCost = mSurvivors[i].cost; |
| 966 | if (thisCost>=minCost) continue; |
| 967 | minCost = thisCost; |
| 968 | minIndex=i; |
| 969 | } |
| 970 | return mSurvivors[minIndex]; |
| 971 | } |
| 972 | |
| 973 | |
| 974 | const ViterbiTCH_AFS7_4::vCand& ViterbiTCH_AFS7_4::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 975 | { |
| 976 | branchCandidates(); |
| 977 | getSoftCostMetrics(inSample,probs,iprobs); |
| 978 | pruneCandidates(); |
| 979 | return minCost(); |
| 980 | } |
| 981 | |
| 982 | |
| 983 | |
| 984 | void ViterbiTCH_AFS7_4::decode(const SoftVector &in, BitVector& target) |
| 985 | { |
| 986 | ViterbiTCH_AFS7_4 &decoder = *this; |
| 987 | const size_t sz = in.size() - 12; |
| 988 | const unsigned deferral = decoder.deferral(); |
| 989 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 990 | assert(sz == decoder.iRate()*target.size()); |
| 991 | |
| 992 | // Build a "history" array where each element contains the full history. |
| 993 | uint32_t history[ctsz]; |
| 994 | { |
| 995 | BitVector bits = in.sliced(); |
| 996 | uint32_t accum = 0; |
| 997 | for (size_t i=0; i<sz; i++) { |
| 998 | accum = (accum<<1) | bits.bit(i); |
| 999 | history[i] = accum; |
| 1000 | } |
| 1001 | // Repeat last bit at the end. |
| 1002 | for (size_t i=sz; i<ctsz; i++) { |
| 1003 | accum = (accum<<1) | (accum & 0x01); |
| 1004 | history[i] = accum; |
| 1005 | } |
| 1006 | } |
| 1007 | |
| 1008 | // Precompute metric tables. |
| 1009 | float matchCostTable[ctsz]; |
| 1010 | float mismatchCostTable[ctsz]; |
| 1011 | { |
| 1012 | const float *dp = in.begin(); |
| 1013 | for (size_t i=0; i<sz; i++) { |
| 1014 | // pVal is the probability that a bit is correct. |
| 1015 | // ipVal is the probability that a bit is incorrect. |
| 1016 | float pVal = dp[i]; |
| 1017 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1018 | float ipVal = 1.0F-pVal; |
| 1019 | // This is a cheap approximation to an ideal cost function. |
| 1020 | if (pVal<0.01F) pVal = 0.01; |
| 1021 | if (ipVal<0.01F) ipVal = 0.01; |
| 1022 | matchCostTable[i] = 0.25F/ipVal; |
| 1023 | mismatchCostTable[i] = 0.25F/pVal; |
| 1024 | } |
| 1025 | |
| 1026 | // pad end of table with unknowns |
| 1027 | for (size_t i=sz; i<ctsz; i++) { |
| 1028 | matchCostTable[i] = 0.5F; |
| 1029 | mismatchCostTable[i] = 0.5F; |
| 1030 | } |
| 1031 | } |
| 1032 | |
| 1033 | { |
| 1034 | decoder.initializeStates(); |
| 1035 | // Each sample of history[] carries its history. |
| 1036 | // So we only have to process every iRate-th sample. |
| 1037 | const unsigned step = decoder.iRate(); |
| 1038 | // input pointer |
| 1039 | const uint32_t *ip = history + step - 1; |
| 1040 | // output pointers |
| 1041 | char *op = target.begin(); |
| 1042 | const char *const opt = target.end(); |
| 1043 | // table pointers |
| 1044 | const float* match = matchCostTable; |
| 1045 | const float* mismatch = mismatchCostTable; |
| 1046 | size_t oCount = 0; |
| 1047 | while (op<opt) { |
| 1048 | // Viterbi algorithm |
| 1049 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1050 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1051 | const ViterbiTCH_AFS7_4::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1052 | ip += step; |
| 1053 | match += step; |
| 1054 | mismatch += step; |
| 1055 | // output |
| 1056 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1057 | oCount++; |
| 1058 | } |
| 1059 | } |
| 1060 | } |
| 1061 | |
| 1062 | |
| 1063 | |
| 1064 | ViterbiTCH_AFS6_7::ViterbiTCH_AFS6_7() |
| 1065 | { |
| 1066 | assert(mDeferral < 32); |
| 1067 | mCoeffs[0] = 0x01b; |
| 1068 | mCoeffsFB[0] = 0x01f; |
| 1069 | mCoeffs[1] = 0x015; |
| 1070 | mCoeffsFB[1] = 0x01f; |
| 1071 | mCoeffs[2] = 0x01f; |
| 1072 | mCoeffsFB[2] = 0x01f; |
| 1073 | mCoeffs[3] = 0x01f; |
| 1074 | mCoeffsFB[3] = 0x01f; |
| 1075 | for (unsigned i = 0; i < mIRate; i++) { |
| 1076 | computeStateTables(i); |
| 1077 | } |
| 1078 | computeGeneratorTable(); |
| 1079 | } |
| 1080 | |
| 1081 | |
| 1082 | |
| 1083 | |
| 1084 | void ViterbiTCH_AFS6_7::initializeStates() |
| 1085 | { |
| 1086 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 1087 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 1088 | } |
| 1089 | |
| 1090 | |
| 1091 | |
| 1092 | void ViterbiTCH_AFS6_7::computeStateTables(unsigned g) |
| 1093 | { |
| 1094 | assert(g<mIRate); |
| 1095 | for (unsigned state=0; state<mIStates; state++) { |
| 1096 | for (unsigned in = 0; in <= 1; in++) { |
| 1097 | uint32_t inputVal = (state<<1) | in; |
| 1098 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 1099 | } |
| 1100 | } |
| 1101 | } |
| 1102 | |
| 1103 | void ViterbiTCH_AFS6_7::computeGeneratorTable() |
| 1104 | { |
| 1105 | for (unsigned index=0; index<mIStates*2; index++) { |
| 1106 | uint32_t t = 0; |
| 1107 | for (unsigned i = 0; i < mIRate; i++) { |
| 1108 | t = (t << 1) | mStateTable[i][index]; |
| 1109 | } |
| 1110 | mGeneratorTable[index] = t; |
| 1111 | } |
| 1112 | } |
| 1113 | |
| 1114 | |
| 1115 | |
| 1116 | |
| 1117 | |
| 1118 | |
| 1119 | void ViterbiTCH_AFS6_7::branchCandidates() |
| 1120 | { |
| 1121 | // Branch to generate new input states. |
| 1122 | const vCand *sp = mSurvivors; |
| 1123 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 1124 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 1125 | for (unsigned in = 0; in <= 1; in++) { |
| 1126 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 1127 | mCandidates[cand+in].cost = sp->cost; |
| 1128 | uint32_t outputs = oStateShifted; |
| 1129 | for (unsigned out = 0; out < mIRate; out++) { |
| 1130 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 1131 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 1132 | mCandidates[cand+in].rState[out] = rState; |
| 1133 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 1134 | } |
| 1135 | mCandidates[cand+in].oState = outputs; |
| 1136 | } |
| 1137 | sp++; |
| 1138 | } |
| 1139 | } |
| 1140 | |
| 1141 | |
| 1142 | void ViterbiTCH_AFS6_7::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 1143 | { |
| 1144 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 1145 | for (unsigned i=0; i<mNumCands; i++) { |
| 1146 | vCand& thisCand = mCandidates[i]; |
| 1147 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 1148 | for (unsigned i = 0; i < mIRate; i++) { |
| 1149 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 1150 | } |
| 1151 | } |
| 1152 | } |
| 1153 | |
| 1154 | |
| 1155 | void ViterbiTCH_AFS6_7::pruneCandidates() |
| 1156 | { |
| 1157 | const vCand* c1 = mCandidates; // 0-prefix |
| 1158 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 1159 | for (unsigned i=0; i<mIStates; i++) { |
| 1160 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 1161 | else mSurvivors[i] = c2[i]; |
| 1162 | } |
| 1163 | } |
| 1164 | |
| 1165 | |
| 1166 | const ViterbiTCH_AFS6_7::vCand& ViterbiTCH_AFS6_7::minCost() const |
| 1167 | { |
| 1168 | int minIndex = 0; |
| 1169 | float minCost = mSurvivors[0].cost; |
| 1170 | for (unsigned i=1; i<mIStates; i++) { |
| 1171 | const float thisCost = mSurvivors[i].cost; |
| 1172 | if (thisCost>=minCost) continue; |
| 1173 | minCost = thisCost; |
| 1174 | minIndex=i; |
| 1175 | } |
| 1176 | return mSurvivors[minIndex]; |
| 1177 | } |
| 1178 | |
| 1179 | |
| 1180 | const ViterbiTCH_AFS6_7::vCand& ViterbiTCH_AFS6_7::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 1181 | { |
| 1182 | branchCandidates(); |
| 1183 | getSoftCostMetrics(inSample,probs,iprobs); |
| 1184 | pruneCandidates(); |
| 1185 | return minCost(); |
| 1186 | } |
| 1187 | |
| 1188 | |
| 1189 | |
| 1190 | void ViterbiTCH_AFS6_7::decode(const SoftVector &in, BitVector& target) |
| 1191 | { |
| 1192 | ViterbiTCH_AFS6_7 &decoder = *this; |
| 1193 | const size_t sz = in.size() - 16; |
| 1194 | const unsigned deferral = decoder.deferral(); |
| 1195 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 1196 | assert(sz == decoder.iRate()*target.size()); |
| 1197 | |
| 1198 | // Build a "history" array where each element contains the full history. |
| 1199 | uint32_t history[ctsz]; |
| 1200 | { |
| 1201 | BitVector bits = in.sliced(); |
| 1202 | uint32_t accum = 0; |
| 1203 | for (size_t i=0; i<sz; i++) { |
| 1204 | accum = (accum<<1) | bits.bit(i); |
| 1205 | history[i] = accum; |
| 1206 | } |
| 1207 | // Repeat last bit at the end. |
| 1208 | for (size_t i=sz; i<ctsz; i++) { |
| 1209 | accum = (accum<<1) | (accum & 0x01); |
| 1210 | history[i] = accum; |
| 1211 | } |
| 1212 | } |
| 1213 | |
| 1214 | // Precompute metric tables. |
| 1215 | float matchCostTable[ctsz]; |
| 1216 | float mismatchCostTable[ctsz]; |
| 1217 | { |
| 1218 | const float *dp = in.begin(); |
| 1219 | for (size_t i=0; i<sz; i++) { |
| 1220 | // pVal is the probability that a bit is correct. |
| 1221 | // ipVal is the probability that a bit is incorrect. |
| 1222 | float pVal = dp[i]; |
| 1223 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1224 | float ipVal = 1.0F-pVal; |
| 1225 | // This is a cheap approximation to an ideal cost function. |
| 1226 | if (pVal<0.01F) pVal = 0.01; |
| 1227 | if (ipVal<0.01F) ipVal = 0.01; |
| 1228 | matchCostTable[i] = 0.25F/ipVal; |
| 1229 | mismatchCostTable[i] = 0.25F/pVal; |
| 1230 | } |
| 1231 | |
| 1232 | // pad end of table with unknowns |
| 1233 | for (size_t i=sz; i<ctsz; i++) { |
| 1234 | matchCostTable[i] = 0.5F; |
| 1235 | mismatchCostTable[i] = 0.5F; |
| 1236 | } |
| 1237 | } |
| 1238 | |
| 1239 | { |
| 1240 | decoder.initializeStates(); |
| 1241 | // Each sample of history[] carries its history. |
| 1242 | // So we only have to process every iRate-th sample. |
| 1243 | const unsigned step = decoder.iRate(); |
| 1244 | // input pointer |
| 1245 | const uint32_t *ip = history + step - 1; |
| 1246 | // output pointers |
| 1247 | char *op = target.begin(); |
| 1248 | const char *const opt = target.end(); |
| 1249 | // table pointers |
| 1250 | const float* match = matchCostTable; |
| 1251 | const float* mismatch = mismatchCostTable; |
| 1252 | size_t oCount = 0; |
| 1253 | while (op<opt) { |
| 1254 | // Viterbi algorithm |
| 1255 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1256 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1257 | const ViterbiTCH_AFS6_7::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1258 | ip += step; |
| 1259 | match += step; |
| 1260 | mismatch += step; |
| 1261 | // output |
| 1262 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1263 | oCount++; |
| 1264 | } |
| 1265 | } |
| 1266 | } |
| 1267 | |
| 1268 | |
| 1269 | |
| 1270 | ViterbiTCH_AFS5_9::ViterbiTCH_AFS5_9() |
| 1271 | { |
| 1272 | assert(mDeferral < 32); |
| 1273 | mCoeffs[0] = 0x06d; |
| 1274 | mCoeffsFB[0] = 0x05f; |
| 1275 | mCoeffs[1] = 0x053; |
| 1276 | mCoeffsFB[1] = 0x05f; |
| 1277 | mCoeffs[2] = 0x05f; |
| 1278 | mCoeffsFB[2] = 0x05f; |
| 1279 | mCoeffs[3] = 0x05f; |
| 1280 | mCoeffsFB[3] = 0x05f; |
| 1281 | for (unsigned i = 0; i < mIRate; i++) { |
| 1282 | computeStateTables(i); |
| 1283 | } |
| 1284 | computeGeneratorTable(); |
| 1285 | } |
| 1286 | |
| 1287 | |
| 1288 | |
| 1289 | |
| 1290 | void ViterbiTCH_AFS5_9::initializeStates() |
| 1291 | { |
| 1292 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 1293 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 1294 | } |
| 1295 | |
| 1296 | |
| 1297 | |
| 1298 | void ViterbiTCH_AFS5_9::computeStateTables(unsigned g) |
| 1299 | { |
| 1300 | assert(g<mIRate); |
| 1301 | for (unsigned state=0; state<mIStates; state++) { |
| 1302 | for (unsigned in = 0; in <= 1; in++) { |
| 1303 | uint32_t inputVal = (state<<1) | in; |
| 1304 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 1305 | } |
| 1306 | } |
| 1307 | } |
| 1308 | |
| 1309 | void ViterbiTCH_AFS5_9::computeGeneratorTable() |
| 1310 | { |
| 1311 | for (unsigned index=0; index<mIStates*2; index++) { |
| 1312 | uint32_t t = 0; |
| 1313 | for (unsigned i = 0; i < mIRate; i++) { |
| 1314 | t = (t << 1) | mStateTable[i][index]; |
| 1315 | } |
| 1316 | mGeneratorTable[index] = t; |
| 1317 | } |
| 1318 | } |
| 1319 | |
| 1320 | |
| 1321 | |
| 1322 | |
| 1323 | |
| 1324 | |
| 1325 | void ViterbiTCH_AFS5_9::branchCandidates() |
| 1326 | { |
| 1327 | // Branch to generate new input states. |
| 1328 | const vCand *sp = mSurvivors; |
| 1329 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 1330 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 1331 | for (unsigned in = 0; in <= 1; in++) { |
| 1332 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 1333 | mCandidates[cand+in].cost = sp->cost; |
| 1334 | uint32_t outputs = oStateShifted; |
| 1335 | for (unsigned out = 0; out < mIRate; out++) { |
| 1336 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 1337 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 1338 | mCandidates[cand+in].rState[out] = rState; |
| 1339 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 1340 | } |
| 1341 | mCandidates[cand+in].oState = outputs; |
| 1342 | } |
| 1343 | sp++; |
| 1344 | } |
| 1345 | } |
| 1346 | |
| 1347 | |
| 1348 | void ViterbiTCH_AFS5_9::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 1349 | { |
| 1350 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 1351 | for (unsigned i=0; i<mNumCands; i++) { |
| 1352 | vCand& thisCand = mCandidates[i]; |
| 1353 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 1354 | for (unsigned i = 0; i < mIRate; i++) { |
| 1355 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 1356 | } |
| 1357 | } |
| 1358 | } |
| 1359 | |
| 1360 | |
| 1361 | void ViterbiTCH_AFS5_9::pruneCandidates() |
| 1362 | { |
| 1363 | const vCand* c1 = mCandidates; // 0-prefix |
| 1364 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 1365 | for (unsigned i=0; i<mIStates; i++) { |
| 1366 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 1367 | else mSurvivors[i] = c2[i]; |
| 1368 | } |
| 1369 | } |
| 1370 | |
| 1371 | |
| 1372 | const ViterbiTCH_AFS5_9::vCand& ViterbiTCH_AFS5_9::minCost() const |
| 1373 | { |
| 1374 | int minIndex = 0; |
| 1375 | float minCost = mSurvivors[0].cost; |
| 1376 | for (unsigned i=1; i<mIStates; i++) { |
| 1377 | const float thisCost = mSurvivors[i].cost; |
| 1378 | if (thisCost>=minCost) continue; |
| 1379 | minCost = thisCost; |
| 1380 | minIndex=i; |
| 1381 | } |
| 1382 | return mSurvivors[minIndex]; |
| 1383 | } |
| 1384 | |
| 1385 | |
| 1386 | const ViterbiTCH_AFS5_9::vCand& ViterbiTCH_AFS5_9::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 1387 | { |
| 1388 | branchCandidates(); |
| 1389 | getSoftCostMetrics(inSample,probs,iprobs); |
| 1390 | pruneCandidates(); |
| 1391 | return minCost(); |
| 1392 | } |
| 1393 | |
| 1394 | |
| 1395 | |
| 1396 | void ViterbiTCH_AFS5_9::decode(const SoftVector &in, BitVector& target) |
| 1397 | { |
| 1398 | ViterbiTCH_AFS5_9 &decoder = *this; |
| 1399 | const size_t sz = in.size() - 24; |
| 1400 | const unsigned deferral = decoder.deferral(); |
| 1401 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 1402 | assert(sz == decoder.iRate()*target.size()); |
| 1403 | |
| 1404 | // Build a "history" array where each element contains the full history. |
| 1405 | uint32_t history[ctsz]; |
| 1406 | { |
| 1407 | BitVector bits = in.sliced(); |
| 1408 | uint32_t accum = 0; |
| 1409 | for (size_t i=0; i<sz; i++) { |
| 1410 | accum = (accum<<1) | bits.bit(i); |
| 1411 | history[i] = accum; |
| 1412 | } |
| 1413 | // Repeat last bit at the end. |
| 1414 | for (size_t i=sz; i<ctsz; i++) { |
| 1415 | accum = (accum<<1) | (accum & 0x01); |
| 1416 | history[i] = accum; |
| 1417 | } |
| 1418 | } |
| 1419 | |
| 1420 | // Precompute metric tables. |
| 1421 | float matchCostTable[ctsz]; |
| 1422 | float mismatchCostTable[ctsz]; |
| 1423 | { |
| 1424 | const float *dp = in.begin(); |
| 1425 | for (size_t i=0; i<sz; i++) { |
| 1426 | // pVal is the probability that a bit is correct. |
| 1427 | // ipVal is the probability that a bit is incorrect. |
| 1428 | float pVal = dp[i]; |
| 1429 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1430 | float ipVal = 1.0F-pVal; |
| 1431 | // This is a cheap approximation to an ideal cost function. |
| 1432 | if (pVal<0.01F) pVal = 0.01; |
| 1433 | if (ipVal<0.01F) ipVal = 0.01; |
| 1434 | matchCostTable[i] = 0.25F/ipVal; |
| 1435 | mismatchCostTable[i] = 0.25F/pVal; |
| 1436 | } |
| 1437 | |
| 1438 | // pad end of table with unknowns |
| 1439 | for (size_t i=sz; i<ctsz; i++) { |
| 1440 | matchCostTable[i] = 0.5F; |
| 1441 | mismatchCostTable[i] = 0.5F; |
| 1442 | } |
| 1443 | } |
| 1444 | |
| 1445 | { |
| 1446 | decoder.initializeStates(); |
| 1447 | // Each sample of history[] carries its history. |
| 1448 | // So we only have to process every iRate-th sample. |
| 1449 | const unsigned step = decoder.iRate(); |
| 1450 | // input pointer |
| 1451 | const uint32_t *ip = history + step - 1; |
| 1452 | // output pointers |
| 1453 | char *op = target.begin(); |
| 1454 | const char *const opt = target.end(); |
| 1455 | // table pointers |
| 1456 | const float* match = matchCostTable; |
| 1457 | const float* mismatch = mismatchCostTable; |
| 1458 | size_t oCount = 0; |
| 1459 | while (op<opt) { |
| 1460 | // Viterbi algorithm |
| 1461 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1462 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1463 | const ViterbiTCH_AFS5_9::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1464 | ip += step; |
| 1465 | match += step; |
| 1466 | mismatch += step; |
| 1467 | // output |
| 1468 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1469 | oCount++; |
| 1470 | } |
| 1471 | } |
| 1472 | } |
| 1473 | |
| 1474 | |
| 1475 | |
| 1476 | ViterbiTCH_AFS5_15::ViterbiTCH_AFS5_15() |
| 1477 | { |
| 1478 | assert(mDeferral < 32); |
| 1479 | mCoeffs[0] = 0x01b; |
| 1480 | mCoeffsFB[0] = 0x01f; |
| 1481 | mCoeffs[1] = 0x01b; |
| 1482 | mCoeffsFB[1] = 0x01f; |
| 1483 | mCoeffs[2] = 0x015; |
| 1484 | mCoeffsFB[2] = 0x01f; |
| 1485 | mCoeffs[3] = 0x01f; |
| 1486 | mCoeffsFB[3] = 0x01f; |
| 1487 | mCoeffs[4] = 0x01f; |
| 1488 | mCoeffsFB[4] = 0x01f; |
| 1489 | for (unsigned i = 0; i < mIRate; i++) { |
| 1490 | computeStateTables(i); |
| 1491 | } |
| 1492 | computeGeneratorTable(); |
| 1493 | } |
| 1494 | |
| 1495 | |
| 1496 | |
| 1497 | |
| 1498 | void ViterbiTCH_AFS5_15::initializeStates() |
| 1499 | { |
| 1500 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 1501 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 1502 | } |
| 1503 | |
| 1504 | |
| 1505 | |
| 1506 | void ViterbiTCH_AFS5_15::computeStateTables(unsigned g) |
| 1507 | { |
| 1508 | assert(g<mIRate); |
| 1509 | for (unsigned state=0; state<mIStates; state++) { |
| 1510 | for (unsigned in = 0; in <= 1; in++) { |
| 1511 | uint32_t inputVal = (state<<1) | in; |
| 1512 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 1513 | } |
| 1514 | } |
| 1515 | } |
| 1516 | |
| 1517 | void ViterbiTCH_AFS5_15::computeGeneratorTable() |
| 1518 | { |
| 1519 | for (unsigned index=0; index<mIStates*2; index++) { |
| 1520 | uint32_t t = 0; |
| 1521 | for (unsigned i = 0; i < mIRate; i++) { |
| 1522 | t = (t << 1) | mStateTable[i][index]; |
| 1523 | } |
| 1524 | mGeneratorTable[index] = t; |
| 1525 | } |
| 1526 | } |
| 1527 | |
| 1528 | |
| 1529 | |
| 1530 | |
| 1531 | |
| 1532 | |
| 1533 | void ViterbiTCH_AFS5_15::branchCandidates() |
| 1534 | { |
| 1535 | // Branch to generate new input states. |
| 1536 | const vCand *sp = mSurvivors; |
| 1537 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 1538 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 1539 | for (unsigned in = 0; in <= 1; in++) { |
| 1540 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 1541 | mCandidates[cand+in].cost = sp->cost; |
| 1542 | uint32_t outputs = oStateShifted; |
| 1543 | for (unsigned out = 0; out < mIRate; out++) { |
| 1544 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 1545 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 1546 | mCandidates[cand+in].rState[out] = rState; |
| 1547 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 1548 | } |
| 1549 | mCandidates[cand+in].oState = outputs; |
| 1550 | } |
| 1551 | sp++; |
| 1552 | } |
| 1553 | } |
| 1554 | |
| 1555 | |
| 1556 | void ViterbiTCH_AFS5_15::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 1557 | { |
| 1558 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 1559 | for (unsigned i=0; i<mNumCands; i++) { |
| 1560 | vCand& thisCand = mCandidates[i]; |
| 1561 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 1562 | for (unsigned i = 0; i < mIRate; i++) { |
| 1563 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 1564 | } |
| 1565 | } |
| 1566 | } |
| 1567 | |
| 1568 | |
| 1569 | void ViterbiTCH_AFS5_15::pruneCandidates() |
| 1570 | { |
| 1571 | const vCand* c1 = mCandidates; // 0-prefix |
| 1572 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 1573 | for (unsigned i=0; i<mIStates; i++) { |
| 1574 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 1575 | else mSurvivors[i] = c2[i]; |
| 1576 | } |
| 1577 | } |
| 1578 | |
| 1579 | |
| 1580 | const ViterbiTCH_AFS5_15::vCand& ViterbiTCH_AFS5_15::minCost() const |
| 1581 | { |
| 1582 | int minIndex = 0; |
| 1583 | float minCost = mSurvivors[0].cost; |
| 1584 | for (unsigned i=1; i<mIStates; i++) { |
| 1585 | const float thisCost = mSurvivors[i].cost; |
| 1586 | if (thisCost>=minCost) continue; |
| 1587 | minCost = thisCost; |
| 1588 | minIndex=i; |
| 1589 | } |
| 1590 | return mSurvivors[minIndex]; |
| 1591 | } |
| 1592 | |
| 1593 | |
| 1594 | const ViterbiTCH_AFS5_15::vCand& ViterbiTCH_AFS5_15::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 1595 | { |
| 1596 | branchCandidates(); |
| 1597 | getSoftCostMetrics(inSample,probs,iprobs); |
| 1598 | pruneCandidates(); |
| 1599 | return minCost(); |
| 1600 | } |
| 1601 | |
| 1602 | |
| 1603 | |
| 1604 | void ViterbiTCH_AFS5_15::decode(const SoftVector &in, BitVector& target) |
| 1605 | { |
| 1606 | ViterbiTCH_AFS5_15 &decoder = *this; |
| 1607 | const size_t sz = in.size() - 20; |
| 1608 | const unsigned deferral = decoder.deferral(); |
| 1609 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 1610 | assert(sz == decoder.iRate()*target.size()); |
| 1611 | |
| 1612 | // Build a "history" array where each element contains the full history. |
| 1613 | uint32_t history[ctsz]; |
| 1614 | { |
| 1615 | BitVector bits = in.sliced(); |
| 1616 | uint32_t accum = 0; |
| 1617 | for (size_t i=0; i<sz; i++) { |
| 1618 | accum = (accum<<1) | bits.bit(i); |
| 1619 | history[i] = accum; |
| 1620 | } |
| 1621 | // Repeat last bit at the end. |
| 1622 | for (size_t i=sz; i<ctsz; i++) { |
| 1623 | accum = (accum<<1) | (accum & 0x01); |
| 1624 | history[i] = accum; |
| 1625 | } |
| 1626 | } |
| 1627 | |
| 1628 | // Precompute metric tables. |
| 1629 | float matchCostTable[ctsz]; |
| 1630 | float mismatchCostTable[ctsz]; |
| 1631 | { |
| 1632 | const float *dp = in.begin(); |
| 1633 | for (size_t i=0; i<sz; i++) { |
| 1634 | // pVal is the probability that a bit is correct. |
| 1635 | // ipVal is the probability that a bit is incorrect. |
| 1636 | float pVal = dp[i]; |
| 1637 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1638 | float ipVal = 1.0F-pVal; |
| 1639 | // This is a cheap approximation to an ideal cost function. |
| 1640 | if (pVal<0.01F) pVal = 0.01; |
| 1641 | if (ipVal<0.01F) ipVal = 0.01; |
| 1642 | matchCostTable[i] = 0.25F/ipVal; |
| 1643 | mismatchCostTable[i] = 0.25F/pVal; |
| 1644 | } |
| 1645 | |
| 1646 | // pad end of table with unknowns |
| 1647 | for (size_t i=sz; i<ctsz; i++) { |
| 1648 | matchCostTable[i] = 0.5F; |
| 1649 | mismatchCostTable[i] = 0.5F; |
| 1650 | } |
| 1651 | } |
| 1652 | |
| 1653 | { |
| 1654 | decoder.initializeStates(); |
| 1655 | // Each sample of history[] carries its history. |
| 1656 | // So we only have to process every iRate-th sample. |
| 1657 | const unsigned step = decoder.iRate(); |
| 1658 | // input pointer |
| 1659 | const uint32_t *ip = history + step - 1; |
| 1660 | // output pointers |
| 1661 | char *op = target.begin(); |
| 1662 | const char *const opt = target.end(); |
| 1663 | // table pointers |
| 1664 | const float* match = matchCostTable; |
| 1665 | const float* mismatch = mismatchCostTable; |
| 1666 | size_t oCount = 0; |
| 1667 | while (op<opt) { |
| 1668 | // Viterbi algorithm |
| 1669 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1670 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1671 | const ViterbiTCH_AFS5_15::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1672 | ip += step; |
| 1673 | match += step; |
| 1674 | mismatch += step; |
| 1675 | // output |
| 1676 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1677 | oCount++; |
| 1678 | } |
| 1679 | } |
| 1680 | } |
| 1681 | |
| 1682 | |
| 1683 | |
| 1684 | ViterbiTCH_AFS4_75::ViterbiTCH_AFS4_75() |
| 1685 | { |
| 1686 | assert(mDeferral < 32); |
| 1687 | mCoeffs[0] = 0x06d; |
| 1688 | mCoeffsFB[0] = 0x05f; |
| 1689 | mCoeffs[1] = 0x06d; |
| 1690 | mCoeffsFB[1] = 0x05f; |
| 1691 | mCoeffs[2] = 0x053; |
| 1692 | mCoeffsFB[2] = 0x05f; |
| 1693 | mCoeffs[3] = 0x05f; |
| 1694 | mCoeffsFB[3] = 0x05f; |
| 1695 | mCoeffs[4] = 0x05f; |
| 1696 | mCoeffsFB[4] = 0x05f; |
| 1697 | for (unsigned i = 0; i < mIRate; i++) { |
| 1698 | computeStateTables(i); |
| 1699 | } |
| 1700 | computeGeneratorTable(); |
| 1701 | } |
| 1702 | |
| 1703 | |
| 1704 | |
| 1705 | |
| 1706 | void ViterbiTCH_AFS4_75::initializeStates() |
| 1707 | { |
| 1708 | for (unsigned i=0; i<mIStates; i++) vitClear(mSurvivors[i]); |
| 1709 | for (unsigned i=0; i<mNumCands; i++) vitClear(mCandidates[i]); |
| 1710 | } |
| 1711 | |
| 1712 | |
| 1713 | |
| 1714 | void ViterbiTCH_AFS4_75::computeStateTables(unsigned g) |
| 1715 | { |
| 1716 | assert(g<mIRate); |
| 1717 | for (unsigned state=0; state<mIStates; state++) { |
| 1718 | for (unsigned in = 0; in <= 1; in++) { |
| 1719 | uint32_t inputVal = (state<<1) | in; |
| 1720 | mStateTable[g][inputVal] = applyPoly(inputVal, mCoeffs[g] ^ mCoeffsFB[g], mOrder+1) ^ in; |
| 1721 | } |
| 1722 | } |
| 1723 | } |
| 1724 | |
| 1725 | void ViterbiTCH_AFS4_75::computeGeneratorTable() |
| 1726 | { |
| 1727 | for (unsigned index=0; index<mIStates*2; index++) { |
| 1728 | uint32_t t = 0; |
| 1729 | for (unsigned i = 0; i < mIRate; i++) { |
| 1730 | t = (t << 1) | mStateTable[i][index]; |
| 1731 | } |
| 1732 | mGeneratorTable[index] = t; |
| 1733 | } |
| 1734 | } |
| 1735 | |
| 1736 | |
| 1737 | |
| 1738 | |
| 1739 | |
| 1740 | |
| 1741 | void ViterbiTCH_AFS4_75::branchCandidates() |
| 1742 | { |
| 1743 | // Branch to generate new input states. |
| 1744 | const vCand *sp = mSurvivors; |
| 1745 | for (unsigned cand=0; cand<mNumCands; cand+=2) { |
| 1746 | uint32_t oStateShifted = (sp->oState) << mIRate; |
| 1747 | for (unsigned in = 0; in <= 1; in++) { |
| 1748 | mCandidates[cand+in].iState = ((sp->iState) << 1) | in; |
| 1749 | mCandidates[cand+in].cost = sp->cost; |
| 1750 | uint32_t outputs = oStateShifted; |
| 1751 | for (unsigned out = 0; out < mIRate; out++) { |
| 1752 | char feedback = applyPoly(sp->rState[out], mCoeffsFB[out] ^ 1, mOrder+1); |
| 1753 | char rState = (((sp->rState[out]) ^ feedback) << 1) | in; |
| 1754 | mCandidates[cand+in].rState[out] = rState; |
| 1755 | outputs |= (mGeneratorTable[rState & mCMask] & (1 << (mIRate - out - 1))); |
| 1756 | } |
| 1757 | mCandidates[cand+in].oState = outputs; |
| 1758 | } |
| 1759 | sp++; |
| 1760 | } |
| 1761 | } |
| 1762 | |
| 1763 | |
| 1764 | void ViterbiTCH_AFS4_75::getSoftCostMetrics(const uint32_t inSample, const float *matchCost, const float *mismatchCost) |
| 1765 | { |
| 1766 | const float *cTab[2] = {matchCost,mismatchCost}; |
| 1767 | for (unsigned i=0; i<mNumCands; i++) { |
| 1768 | vCand& thisCand = mCandidates[i]; |
| 1769 | const unsigned mismatched = inSample ^ (thisCand.oState); |
| 1770 | for (unsigned i = 0; i < mIRate; i++) { |
| 1771 | thisCand.cost += cTab[(mismatched>>i)&0x01][mIRate-i-1]; |
| 1772 | } |
| 1773 | } |
| 1774 | } |
| 1775 | |
| 1776 | |
| 1777 | void ViterbiTCH_AFS4_75::pruneCandidates() |
| 1778 | { |
| 1779 | const vCand* c1 = mCandidates; // 0-prefix |
| 1780 | const vCand* c2 = mCandidates + mIStates; // 1-prefix |
| 1781 | for (unsigned i=0; i<mIStates; i++) { |
| 1782 | if (c1[i].cost < c2[i].cost) mSurvivors[i] = c1[i]; |
| 1783 | else mSurvivors[i] = c2[i]; |
| 1784 | } |
| 1785 | } |
| 1786 | |
| 1787 | |
| 1788 | const ViterbiTCH_AFS4_75::vCand& ViterbiTCH_AFS4_75::minCost() const |
| 1789 | { |
| 1790 | int minIndex = 0; |
| 1791 | float minCost = mSurvivors[0].cost; |
| 1792 | for (unsigned i=1; i<mIStates; i++) { |
| 1793 | const float thisCost = mSurvivors[i].cost; |
| 1794 | if (thisCost>=minCost) continue; |
| 1795 | minCost = thisCost; |
| 1796 | minIndex=i; |
| 1797 | } |
| 1798 | return mSurvivors[minIndex]; |
| 1799 | } |
| 1800 | |
| 1801 | |
| 1802 | const ViterbiTCH_AFS4_75::vCand& ViterbiTCH_AFS4_75::step(uint32_t inSample, const float *probs, const float *iprobs) |
| 1803 | { |
| 1804 | branchCandidates(); |
| 1805 | getSoftCostMetrics(inSample,probs,iprobs); |
| 1806 | pruneCandidates(); |
| 1807 | return minCost(); |
| 1808 | } |
| 1809 | |
| 1810 | |
| 1811 | |
| 1812 | void ViterbiTCH_AFS4_75::decode(const SoftVector &in, BitVector& target) |
| 1813 | { |
| 1814 | ViterbiTCH_AFS4_75 &decoder = *this; |
| 1815 | const size_t sz = in.size() - 30; |
| 1816 | const unsigned deferral = decoder.deferral(); |
| 1817 | const size_t ctsz = sz + deferral*decoder.iRate(); |
| 1818 | assert(sz == decoder.iRate()*target.size()); |
| 1819 | |
| 1820 | // Build a "history" array where each element contains the full history. |
| 1821 | uint32_t history[ctsz]; |
| 1822 | { |
| 1823 | BitVector bits = in.sliced(); |
| 1824 | uint32_t accum = 0; |
| 1825 | for (size_t i=0; i<sz; i++) { |
| 1826 | accum = (accum<<1) | bits.bit(i); |
| 1827 | history[i] = accum; |
| 1828 | } |
| 1829 | // Repeat last bit at the end. |
| 1830 | for (size_t i=sz; i<ctsz; i++) { |
| 1831 | accum = (accum<<1) | (accum & 0x01); |
| 1832 | history[i] = accum; |
| 1833 | } |
| 1834 | } |
| 1835 | |
| 1836 | // Precompute metric tables. |
| 1837 | float matchCostTable[ctsz]; |
| 1838 | float mismatchCostTable[ctsz]; |
| 1839 | { |
| 1840 | const float *dp = in.begin(); |
| 1841 | for (size_t i=0; i<sz; i++) { |
| 1842 | // pVal is the probability that a bit is correct. |
| 1843 | // ipVal is the probability that a bit is incorrect. |
| 1844 | float pVal = dp[i]; |
| 1845 | if (pVal>0.5F) pVal = 1.0F-pVal; |
| 1846 | float ipVal = 1.0F-pVal; |
| 1847 | // This is a cheap approximation to an ideal cost function. |
| 1848 | if (pVal<0.01F) pVal = 0.01; |
| 1849 | if (ipVal<0.01F) ipVal = 0.01; |
| 1850 | matchCostTable[i] = 0.25F/ipVal; |
| 1851 | mismatchCostTable[i] = 0.25F/pVal; |
| 1852 | } |
| 1853 | |
| 1854 | // pad end of table with unknowns |
| 1855 | for (size_t i=sz; i<ctsz; i++) { |
| 1856 | matchCostTable[i] = 0.5F; |
| 1857 | mismatchCostTable[i] = 0.5F; |
| 1858 | } |
| 1859 | } |
| 1860 | |
| 1861 | { |
| 1862 | decoder.initializeStates(); |
| 1863 | // Each sample of history[] carries its history. |
| 1864 | // So we only have to process every iRate-th sample. |
| 1865 | const unsigned step = decoder.iRate(); |
| 1866 | // input pointer |
| 1867 | const uint32_t *ip = history + step - 1; |
| 1868 | // output pointers |
| 1869 | char *op = target.begin(); |
| 1870 | const char *const opt = target.end(); |
| 1871 | // table pointers |
| 1872 | const float* match = matchCostTable; |
| 1873 | const float* mismatch = mismatchCostTable; |
| 1874 | size_t oCount = 0; |
| 1875 | while (op<opt) { |
| 1876 | // Viterbi algorithm |
| 1877 | assert(match-matchCostTable<(int)(sizeof(matchCostTable)/sizeof(matchCostTable[0])-1)); |
| 1878 | assert(mismatch-mismatchCostTable<(int)(sizeof(mismatchCostTable)/sizeof(mismatchCostTable[0])-1)); |
| 1879 | const ViterbiTCH_AFS4_75::vCand &minCost = decoder.step(*ip, match, mismatch); |
| 1880 | ip += step; |
| 1881 | match += step; |
| 1882 | mismatch += step; |
| 1883 | // output |
| 1884 | if (oCount>=deferral) *op++ = (minCost.iState >> deferral)&0x01; |
| 1885 | oCount++; |
| 1886 | } |
| 1887 | } |
| 1888 | } |
| 1889 | |
| 1890 | |
| 1891 | |