Alexandre Lision | 7c6f4a6 | 2013-09-05 13:27:01 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische |
| 3 | * Universitaet Berlin. See the accompanying file "COPYRIGHT" for |
| 4 | * details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. |
| 5 | */ |
| 6 | |
| 7 | #include <stdio.h> |
| 8 | #include <assert.h> |
| 9 | |
| 10 | #include "gsm610_priv.h" |
| 11 | |
| 12 | /* |
| 13 | * 4.2.11 .. 4.2.12 LONG TERM PREDICTOR (LTP) SECTION |
| 14 | */ |
| 15 | |
| 16 | |
| 17 | /* |
| 18 | * This module computes the LTP gain (bc) and the LTP lag (Nc) |
| 19 | * for the long term analysis filter. This is done by calculating a |
| 20 | * maximum of the cross-correlation function between the current |
| 21 | * sub-segment short term residual signal d[0..39] (output of |
| 22 | * the short term analysis filter; for simplification the index |
| 23 | * of this array begins at 0 and ends at 39 for each sub-segment of the |
| 24 | * RPE-LTP analysis) and the previous reconstructed short term |
| 25 | * residual signal dp[ -120 .. -1 ]. A dynamic scaling must be |
| 26 | * performed to avoid overflow. |
| 27 | */ |
| 28 | |
| 29 | /* The next procedure exists in six versions. First two integer |
| 30 | * version (if USE_FLOAT_MUL is not defined); then four floating |
| 31 | * point versions, twice with proper scaling (USE_FLOAT_MUL defined), |
| 32 | * once without (USE_FLOAT_MUL and FAST defined, and fast run-time |
| 33 | * option used). Every pair has first a Cut version (see the -C |
| 34 | * option to toast or the LTP_CUT option to gsm_option()), then the |
| 35 | * uncut one. (For a detailed explanation of why this is altogether |
| 36 | * a bad idea, see Henry Spencer and Geoff Collyer, ``#ifdef Considered |
| 37 | * Harmful''.) |
| 38 | */ |
| 39 | |
| 40 | #ifndef USE_FLOAT_MUL |
| 41 | |
| 42 | #ifdef LTP_CUT |
| 43 | |
| 44 | static void Cut_Calculation_of_the_LTP_parameters ( |
| 45 | |
| 46 | struct gsm_state * st, |
| 47 | |
| 48 | register word * d, /* [0..39] IN */ |
| 49 | register word * dp, /* [-120..-1] IN */ |
| 50 | word * bc_out, /* OUT */ |
| 51 | word * Nc_out /* OUT */ |
| 52 | ) |
| 53 | { |
| 54 | register int k, lambda; |
| 55 | word Nc, bc; |
| 56 | word wt[40]; |
| 57 | |
| 58 | longword L_result; |
| 59 | longword L_max, L_power; |
| 60 | word R, S, dmax, scal, best_k; |
| 61 | word ltp_cut; |
| 62 | |
| 63 | register word temp, wt_k; |
| 64 | |
| 65 | /* Search of the optimum scaling of d[0..39]. |
| 66 | */ |
| 67 | dmax = 0; |
| 68 | for (k = 0; k <= 39; k++) { |
| 69 | temp = d[k]; |
| 70 | temp = GSM_ABS( temp ); |
| 71 | if (temp > dmax) { |
| 72 | dmax = temp; |
| 73 | best_k = k; |
| 74 | } |
| 75 | } |
| 76 | temp = 0; |
| 77 | if (dmax == 0) scal = 0; |
| 78 | else { |
| 79 | assert(dmax > 0); |
| 80 | temp = gsm_norm( (longword)dmax << 16 ); |
| 81 | } |
| 82 | if (temp > 6) scal = 0; |
| 83 | else scal = 6 - temp; |
| 84 | assert(scal >= 0); |
| 85 | |
| 86 | /* Search for the maximum cross-correlation and coding of the LTP lag |
| 87 | */ |
| 88 | L_max = 0; |
| 89 | Nc = 40; /* index for the maximum cross-correlation */ |
| 90 | wt_k = SASR_W(d[best_k], scal); |
| 91 | |
| 92 | for (lambda = 40; lambda <= 120; lambda++) { |
| 93 | L_result = (longword)wt_k * dp[best_k - lambda]; |
| 94 | if (L_result > L_max) { |
| 95 | Nc = lambda; |
| 96 | L_max = L_result; |
| 97 | } |
| 98 | } |
| 99 | *Nc_out = Nc; |
| 100 | L_max <<= 1; |
| 101 | |
| 102 | /* Rescaling of L_max |
| 103 | */ |
| 104 | assert(scal <= 100 && scal >= -100); |
| 105 | L_max = L_max >> (6 - scal); /* sub(6, scal) */ |
| 106 | |
| 107 | assert( Nc <= 120 && Nc >= 40); |
| 108 | |
| 109 | /* Compute the power of the reconstructed short term residual |
| 110 | * signal dp[..] |
| 111 | */ |
| 112 | L_power = 0; |
| 113 | for (k = 0; k <= 39; k++) { |
| 114 | |
| 115 | register longword L_temp; |
| 116 | |
| 117 | L_temp = SASR_W( dp[k - Nc], 3 ); |
| 118 | L_power += L_temp * L_temp; |
| 119 | } |
| 120 | L_power <<= 1; /* from L_MULT */ |
| 121 | |
| 122 | /* Normalization of L_max and L_power |
| 123 | */ |
| 124 | |
| 125 | if (L_max <= 0) { |
| 126 | *bc_out = 0; |
| 127 | return; |
| 128 | } |
| 129 | if (L_max >= L_power) { |
| 130 | *bc_out = 3; |
| 131 | return; |
| 132 | } |
| 133 | |
| 134 | temp = gsm_norm( L_power ); |
| 135 | |
| 136 | R = SASR( L_max << temp, 16 ); |
| 137 | S = SASR( L_power << temp, 16 ); |
| 138 | |
| 139 | /* Coding of the LTP gain |
| 140 | */ |
| 141 | |
| 142 | /* Table 4.3a must be used to obtain the level DLB[i] for the |
| 143 | * quantization of the LTP gain b to get the coded version bc. |
| 144 | */ |
| 145 | for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break; |
| 146 | *bc_out = bc; |
| 147 | } |
| 148 | |
| 149 | #endif /* LTP_CUT */ |
| 150 | |
| 151 | static void Calculation_of_the_LTP_parameters ( |
| 152 | register word * d, /* [0..39] IN */ |
| 153 | register word * dp, /* [-120..-1] IN */ |
| 154 | word * bc_out, /* OUT */ |
| 155 | word * Nc_out /* OUT */ |
| 156 | ) |
| 157 | { |
| 158 | register int k, lambda; |
| 159 | word Nc, bc; |
| 160 | word wt[40]; |
| 161 | |
| 162 | longword L_max, L_power; |
| 163 | word R, S, dmax, scal; |
| 164 | register word temp; |
| 165 | |
| 166 | /* Search of the optimum scaling of d[0..39]. |
| 167 | */ |
| 168 | dmax = 0; |
| 169 | |
| 170 | for (k = 0; k <= 39; k++) { |
| 171 | temp = d[k]; |
| 172 | temp = GSM_ABS( temp ); |
| 173 | if (temp > dmax) dmax = temp; |
| 174 | } |
| 175 | |
| 176 | temp = 0; |
| 177 | if (dmax == 0) scal = 0; |
| 178 | else { |
| 179 | assert(dmax > 0); |
| 180 | temp = gsm_norm( (longword)dmax << 16 ); |
| 181 | } |
| 182 | |
| 183 | if (temp > 6) scal = 0; |
| 184 | else scal = 6 - temp; |
| 185 | |
| 186 | assert(scal >= 0); |
| 187 | |
| 188 | /* Initialization of a working array wt |
| 189 | */ |
| 190 | |
| 191 | for (k = 0; k <= 39; k++) wt[k] = SASR_W( d[k], scal ); |
| 192 | |
| 193 | /* Search for the maximum cross-correlation and coding of the LTP lag |
| 194 | */ |
| 195 | L_max = 0; |
| 196 | Nc = 40; /* index for the maximum cross-correlation */ |
| 197 | |
| 198 | for (lambda = 40; lambda <= 120; lambda++) { |
| 199 | |
| 200 | # undef STEP |
| 201 | # define STEP(k) (longword)wt[k] * dp[k - lambda] |
| 202 | |
| 203 | register longword L_result; |
| 204 | |
| 205 | L_result = STEP(0) ; L_result += STEP(1) ; |
| 206 | L_result += STEP(2) ; L_result += STEP(3) ; |
| 207 | L_result += STEP(4) ; L_result += STEP(5) ; |
| 208 | L_result += STEP(6) ; L_result += STEP(7) ; |
| 209 | L_result += STEP(8) ; L_result += STEP(9) ; |
| 210 | L_result += STEP(10) ; L_result += STEP(11) ; |
| 211 | L_result += STEP(12) ; L_result += STEP(13) ; |
| 212 | L_result += STEP(14) ; L_result += STEP(15) ; |
| 213 | L_result += STEP(16) ; L_result += STEP(17) ; |
| 214 | L_result += STEP(18) ; L_result += STEP(19) ; |
| 215 | L_result += STEP(20) ; L_result += STEP(21) ; |
| 216 | L_result += STEP(22) ; L_result += STEP(23) ; |
| 217 | L_result += STEP(24) ; L_result += STEP(25) ; |
| 218 | L_result += STEP(26) ; L_result += STEP(27) ; |
| 219 | L_result += STEP(28) ; L_result += STEP(29) ; |
| 220 | L_result += STEP(30) ; L_result += STEP(31) ; |
| 221 | L_result += STEP(32) ; L_result += STEP(33) ; |
| 222 | L_result += STEP(34) ; L_result += STEP(35) ; |
| 223 | L_result += STEP(36) ; L_result += STEP(37) ; |
| 224 | L_result += STEP(38) ; L_result += STEP(39) ; |
| 225 | |
| 226 | if (L_result > L_max) { |
| 227 | |
| 228 | Nc = lambda; |
| 229 | L_max = L_result; |
| 230 | } |
| 231 | } |
| 232 | |
| 233 | *Nc_out = Nc; |
| 234 | |
| 235 | L_max <<= 1; |
| 236 | |
| 237 | /* Rescaling of L_max |
| 238 | */ |
| 239 | assert(scal <= 100 && scal >= -100); |
| 240 | L_max = L_max >> (6 - scal); /* sub(6, scal) */ |
| 241 | |
| 242 | assert( Nc <= 120 && Nc >= 40); |
| 243 | |
| 244 | /* Compute the power of the reconstructed short term residual |
| 245 | * signal dp[..] |
| 246 | */ |
| 247 | L_power = 0; |
| 248 | for (k = 0; k <= 39; k++) { |
| 249 | |
| 250 | register longword L_temp; |
| 251 | |
| 252 | L_temp = SASR_W( dp[k - Nc], 3 ); |
| 253 | L_power += L_temp * L_temp; |
| 254 | } |
| 255 | L_power <<= 1; /* from L_MULT */ |
| 256 | |
| 257 | /* Normalization of L_max and L_power |
| 258 | */ |
| 259 | |
| 260 | if (L_max <= 0) { |
| 261 | *bc_out = 0; |
| 262 | return; |
| 263 | } |
| 264 | if (L_max >= L_power) { |
| 265 | *bc_out = 3; |
| 266 | return; |
| 267 | } |
| 268 | |
| 269 | temp = gsm_norm( L_power ); |
| 270 | |
| 271 | R = SASR_L( L_max << temp, 16 ); |
| 272 | S = SASR_L( L_power << temp, 16 ); |
| 273 | |
| 274 | /* Coding of the LTP gain |
| 275 | */ |
| 276 | |
| 277 | /* Table 4.3a must be used to obtain the level DLB[i] for the |
| 278 | * quantization of the LTP gain b to get the coded version bc. |
| 279 | */ |
| 280 | for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break; |
| 281 | *bc_out = bc; |
| 282 | } |
| 283 | |
| 284 | #else /* USE_FLOAT_MUL */ |
| 285 | |
| 286 | #ifdef LTP_CUT |
| 287 | |
| 288 | static void Cut_Calculation_of_the_LTP_parameters ( |
| 289 | struct gsm_state * st, /* IN */ |
| 290 | register word * d, /* [0..39] IN */ |
| 291 | register word * dp, /* [-120..-1] IN */ |
| 292 | word * bc_out, /* OUT */ |
| 293 | word * Nc_out /* OUT */ |
| 294 | ) |
| 295 | { |
| 296 | register int k, lambda; |
| 297 | word Nc, bc; |
| 298 | word ltp_cut; |
| 299 | |
| 300 | float wt_float[40]; |
| 301 | float dp_float_base[120], * dp_float = dp_float_base + 120; |
| 302 | |
| 303 | longword L_max, L_power; |
| 304 | word R, S, dmax, scal; |
| 305 | register word temp; |
| 306 | |
| 307 | /* Search of the optimum scaling of d[0..39]. |
| 308 | */ |
| 309 | dmax = 0; |
| 310 | |
| 311 | for (k = 0; k <= 39; k++) { |
| 312 | temp = d[k]; |
| 313 | temp = GSM_ABS( temp ); |
| 314 | if (temp > dmax) dmax = temp; |
| 315 | } |
| 316 | |
| 317 | temp = 0; |
| 318 | if (dmax == 0) scal = 0; |
| 319 | else { |
| 320 | assert(dmax > 0); |
| 321 | temp = gsm_norm( (longword)dmax << 16 ); |
| 322 | } |
| 323 | |
| 324 | if (temp > 6) scal = 0; |
| 325 | else scal = 6 - temp; |
| 326 | |
| 327 | assert(scal >= 0); |
| 328 | ltp_cut = (longword)SASR_W(dmax, scal) * st->ltp_cut / 100; |
| 329 | |
| 330 | |
| 331 | /* Initialization of a working array wt |
| 332 | */ |
| 333 | |
| 334 | for (k = 0; k < 40; k++) { |
| 335 | register word w = SASR_W( d[k], scal ); |
| 336 | if (w < 0 ? w > -ltp_cut : w < ltp_cut) { |
| 337 | wt_float[k] = 0.0; |
| 338 | } |
| 339 | else { |
| 340 | wt_float[k] = w; |
| 341 | } |
| 342 | } |
| 343 | for (k = -120; k < 0; k++) dp_float[k] = dp[k]; |
| 344 | |
| 345 | /* Search for the maximum cross-correlation and coding of the LTP lag |
| 346 | */ |
| 347 | L_max = 0; |
| 348 | Nc = 40; /* index for the maximum cross-correlation */ |
| 349 | |
| 350 | for (lambda = 40; lambda <= 120; lambda += 9) { |
| 351 | |
| 352 | /* Calculate L_result for l = lambda .. lambda + 9. |
| 353 | */ |
| 354 | register float *lp = dp_float - lambda; |
| 355 | |
| 356 | register float W; |
| 357 | register float a = lp[-8], b = lp[-7], c = lp[-6], |
| 358 | d = lp[-5], e = lp[-4], f = lp[-3], |
| 359 | g = lp[-2], h = lp[-1]; |
| 360 | register float E; |
| 361 | register float S0 = 0, S1 = 0, S2 = 0, S3 = 0, S4 = 0, |
| 362 | S5 = 0, S6 = 0, S7 = 0, S8 = 0; |
| 363 | |
| 364 | # undef STEP |
| 365 | # define STEP(K, a, b, c, d, e, f, g, h) \ |
| 366 | if ((W = wt_float[K]) != 0.0) { \ |
| 367 | E = W * a; S8 += E; \ |
| 368 | E = W * b; S7 += E; \ |
| 369 | E = W * c; S6 += E; \ |
| 370 | E = W * d; S5 += E; \ |
| 371 | E = W * e; S4 += E; \ |
| 372 | E = W * f; S3 += E; \ |
| 373 | E = W * g; S2 += E; \ |
| 374 | E = W * h; S1 += E; \ |
| 375 | a = lp[K]; \ |
| 376 | E = W * a; S0 += E; } else (a = lp[K]) |
| 377 | |
| 378 | # define STEP_A(K) STEP(K, a, b, c, d, e, f, g, h) |
| 379 | # define STEP_B(K) STEP(K, b, c, d, e, f, g, h, a) |
| 380 | # define STEP_C(K) STEP(K, c, d, e, f, g, h, a, b) |
| 381 | # define STEP_D(K) STEP(K, d, e, f, g, h, a, b, c) |
| 382 | # define STEP_E(K) STEP(K, e, f, g, h, a, b, c, d) |
| 383 | # define STEP_F(K) STEP(K, f, g, h, a, b, c, d, e) |
| 384 | # define STEP_G(K) STEP(K, g, h, a, b, c, d, e, f) |
| 385 | # define STEP_H(K) STEP(K, h, a, b, c, d, e, f, g) |
| 386 | |
| 387 | STEP_A( 0); STEP_B( 1); STEP_C( 2); STEP_D( 3); |
| 388 | STEP_E( 4); STEP_F( 5); STEP_G( 6); STEP_H( 7); |
| 389 | |
| 390 | STEP_A( 8); STEP_B( 9); STEP_C(10); STEP_D(11); |
| 391 | STEP_E(12); STEP_F(13); STEP_G(14); STEP_H(15); |
| 392 | |
| 393 | STEP_A(16); STEP_B(17); STEP_C(18); STEP_D(19); |
| 394 | STEP_E(20); STEP_F(21); STEP_G(22); STEP_H(23); |
| 395 | |
| 396 | STEP_A(24); STEP_B(25); STEP_C(26); STEP_D(27); |
| 397 | STEP_E(28); STEP_F(29); STEP_G(30); STEP_H(31); |
| 398 | |
| 399 | STEP_A(32); STEP_B(33); STEP_C(34); STEP_D(35); |
| 400 | STEP_E(36); STEP_F(37); STEP_G(38); STEP_H(39); |
| 401 | |
| 402 | # undef STEP_A |
| 403 | # undef STEP_B |
| 404 | # undef STEP_C |
| 405 | # undef STEP_D |
| 406 | # undef STEP_E |
| 407 | # undef STEP_F |
| 408 | # undef STEP_G |
| 409 | # undef STEP_H |
| 410 | |
| 411 | if (S0 > L_max) { L_max = S0; Nc = lambda; } |
| 412 | if (S1 > L_max) { L_max = S1; Nc = lambda + 1; } |
| 413 | if (S2 > L_max) { L_max = S2; Nc = lambda + 2; } |
| 414 | if (S3 > L_max) { L_max = S3; Nc = lambda + 3; } |
| 415 | if (S4 > L_max) { L_max = S4; Nc = lambda + 4; } |
| 416 | if (S5 > L_max) { L_max = S5; Nc = lambda + 5; } |
| 417 | if (S6 > L_max) { L_max = S6; Nc = lambda + 6; } |
| 418 | if (S7 > L_max) { L_max = S7; Nc = lambda + 7; } |
| 419 | if (S8 > L_max) { L_max = S8; Nc = lambda + 8; } |
| 420 | |
| 421 | } |
| 422 | *Nc_out = Nc; |
| 423 | |
| 424 | L_max <<= 1; |
| 425 | |
| 426 | /* Rescaling of L_max |
| 427 | */ |
| 428 | assert(scal <= 100 && scal >= -100); |
| 429 | L_max = L_max >> (6 - scal); /* sub(6, scal) */ |
| 430 | |
| 431 | assert( Nc <= 120 && Nc >= 40); |
| 432 | |
| 433 | /* Compute the power of the reconstructed short term residual |
| 434 | * signal dp[..] |
| 435 | */ |
| 436 | L_power = 0; |
| 437 | for (k = 0; k <= 39; k++) { |
| 438 | |
| 439 | register longword L_temp; |
| 440 | |
| 441 | L_temp = SASR_W( dp[k - Nc], 3 ); |
| 442 | L_power += L_temp * L_temp; |
| 443 | } |
| 444 | L_power <<= 1; /* from L_MULT */ |
| 445 | |
| 446 | /* Normalization of L_max and L_power |
| 447 | */ |
| 448 | |
| 449 | if (L_max <= 0) { |
| 450 | *bc_out = 0; |
| 451 | return; |
| 452 | } |
| 453 | if (L_max >= L_power) { |
| 454 | *bc_out = 3; |
| 455 | return; |
| 456 | } |
| 457 | |
| 458 | temp = gsm_norm( L_power ); |
| 459 | |
| 460 | R = SASR( L_max << temp, 16 ); |
| 461 | S = SASR( L_power << temp, 16 ); |
| 462 | |
| 463 | /* Coding of the LTP gain |
| 464 | */ |
| 465 | |
| 466 | /* Table 4.3a must be used to obtain the level DLB[i] for the |
| 467 | * quantization of the LTP gain b to get the coded version bc. |
| 468 | */ |
| 469 | for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break; |
| 470 | *bc_out = bc; |
| 471 | } |
| 472 | |
| 473 | #endif /* LTP_CUT */ |
| 474 | |
| 475 | static void Calculation_of_the_LTP_parameters ( |
| 476 | register word * din, /* [0..39] IN */ |
| 477 | register word * dp, /* [-120..-1] IN */ |
| 478 | word * bc_out, /* OUT */ |
| 479 | word * Nc_out /* OUT */ |
| 480 | ) |
| 481 | { |
| 482 | register int k, lambda; |
| 483 | word Nc, bc; |
| 484 | |
| 485 | float wt_float[40]; |
| 486 | float dp_float_base[120], * dp_float = dp_float_base + 120; |
| 487 | |
| 488 | longword L_max, L_power; |
| 489 | word R, S, dmax, scal; |
| 490 | register word temp; |
| 491 | |
| 492 | /* Search of the optimum scaling of d[0..39]. |
| 493 | */ |
| 494 | dmax = 0; |
| 495 | |
| 496 | for (k = 0; k <= 39; k++) { |
| 497 | temp = din [k] ; |
| 498 | temp = GSM_ABS (temp) ; |
| 499 | if (temp > dmax) dmax = temp; |
| 500 | } |
| 501 | |
| 502 | temp = 0; |
| 503 | if (dmax == 0) scal = 0; |
| 504 | else { |
| 505 | assert(dmax > 0); |
| 506 | temp = gsm_norm( (longword)dmax << 16 ); |
| 507 | } |
| 508 | |
| 509 | if (temp > 6) scal = 0; |
| 510 | else scal = 6 - temp; |
| 511 | |
| 512 | assert(scal >= 0); |
| 513 | |
| 514 | /* Initialization of a working array wt |
| 515 | */ |
| 516 | |
| 517 | for (k = 0; k < 40; k++) wt_float[k] = SASR_W (din [k], scal) ; |
| 518 | for (k = -120; k < 0; k++) dp_float[k] = dp[k]; |
| 519 | |
| 520 | /* Search for the maximum cross-correlation and coding of the LTP lag |
| 521 | */ |
| 522 | L_max = 0; |
| 523 | Nc = 40; /* index for the maximum cross-correlation */ |
| 524 | |
| 525 | for (lambda = 40; lambda <= 120; lambda += 9) { |
| 526 | |
| 527 | /* Calculate L_result for l = lambda .. lambda + 9. |
| 528 | */ |
| 529 | register float *lp = dp_float - lambda; |
| 530 | |
| 531 | register float W; |
| 532 | register float a = lp[-8], b = lp[-7], c = lp[-6], |
| 533 | d = lp[-5], e = lp[-4], f = lp[-3], |
| 534 | g = lp[-2], h = lp[-1]; |
| 535 | register float E; |
| 536 | register float S0 = 0, S1 = 0, S2 = 0, S3 = 0, S4 = 0, |
| 537 | S5 = 0, S6 = 0, S7 = 0, S8 = 0; |
| 538 | |
| 539 | # undef STEP |
| 540 | # define STEP(K, a, b, c, d, e, f, g, h) \ |
| 541 | W = wt_float[K]; \ |
| 542 | E = W * a; S8 += E; \ |
| 543 | E = W * b; S7 += E; \ |
| 544 | E = W * c; S6 += E; \ |
| 545 | E = W * d; S5 += E; \ |
| 546 | E = W * e; S4 += E; \ |
| 547 | E = W * f; S3 += E; \ |
| 548 | E = W * g; S2 += E; \ |
| 549 | E = W * h; S1 += E; \ |
| 550 | a = lp[K]; \ |
| 551 | E = W * a; S0 += E |
| 552 | |
| 553 | # define STEP_A(K) STEP(K, a, b, c, d, e, f, g, h) |
| 554 | # define STEP_B(K) STEP(K, b, c, d, e, f, g, h, a) |
| 555 | # define STEP_C(K) STEP(K, c, d, e, f, g, h, a, b) |
| 556 | # define STEP_D(K) STEP(K, d, e, f, g, h, a, b, c) |
| 557 | # define STEP_E(K) STEP(K, e, f, g, h, a, b, c, d) |
| 558 | # define STEP_F(K) STEP(K, f, g, h, a, b, c, d, e) |
| 559 | # define STEP_G(K) STEP(K, g, h, a, b, c, d, e, f) |
| 560 | # define STEP_H(K) STEP(K, h, a, b, c, d, e, f, g) |
| 561 | |
| 562 | STEP_A( 0); STEP_B( 1); STEP_C( 2); STEP_D( 3); |
| 563 | STEP_E( 4); STEP_F( 5); STEP_G( 6); STEP_H( 7); |
| 564 | |
| 565 | STEP_A( 8); STEP_B( 9); STEP_C(10); STEP_D(11); |
| 566 | STEP_E(12); STEP_F(13); STEP_G(14); STEP_H(15); |
| 567 | |
| 568 | STEP_A(16); STEP_B(17); STEP_C(18); STEP_D(19); |
| 569 | STEP_E(20); STEP_F(21); STEP_G(22); STEP_H(23); |
| 570 | |
| 571 | STEP_A(24); STEP_B(25); STEP_C(26); STEP_D(27); |
| 572 | STEP_E(28); STEP_F(29); STEP_G(30); STEP_H(31); |
| 573 | |
| 574 | STEP_A(32); STEP_B(33); STEP_C(34); STEP_D(35); |
| 575 | STEP_E(36); STEP_F(37); STEP_G(38); STEP_H(39); |
| 576 | |
| 577 | # undef STEP_A |
| 578 | # undef STEP_B |
| 579 | # undef STEP_C |
| 580 | # undef STEP_D |
| 581 | # undef STEP_E |
| 582 | # undef STEP_F |
| 583 | # undef STEP_G |
| 584 | # undef STEP_H |
| 585 | |
| 586 | if (S0 > L_max) { L_max = S0; Nc = lambda; } |
| 587 | if (S1 > L_max) { L_max = S1; Nc = lambda + 1; } |
| 588 | if (S2 > L_max) { L_max = S2; Nc = lambda + 2; } |
| 589 | if (S3 > L_max) { L_max = S3; Nc = lambda + 3; } |
| 590 | if (S4 > L_max) { L_max = S4; Nc = lambda + 4; } |
| 591 | if (S5 > L_max) { L_max = S5; Nc = lambda + 5; } |
| 592 | if (S6 > L_max) { L_max = S6; Nc = lambda + 6; } |
| 593 | if (S7 > L_max) { L_max = S7; Nc = lambda + 7; } |
| 594 | if (S8 > L_max) { L_max = S8; Nc = lambda + 8; } |
| 595 | } |
| 596 | *Nc_out = Nc; |
| 597 | |
| 598 | L_max <<= 1; |
| 599 | |
| 600 | /* Rescaling of L_max |
| 601 | */ |
| 602 | assert(scal <= 100 && scal >= -100); |
| 603 | L_max = L_max >> (6 - scal); /* sub(6, scal) */ |
| 604 | |
| 605 | assert( Nc <= 120 && Nc >= 40); |
| 606 | |
| 607 | /* Compute the power of the reconstructed short term residual |
| 608 | * signal dp[..] |
| 609 | */ |
| 610 | L_power = 0; |
| 611 | for (k = 0; k <= 39; k++) { |
| 612 | |
| 613 | register longword L_temp; |
| 614 | |
| 615 | L_temp = SASR_W( dp[k - Nc], 3 ); |
| 616 | L_power += L_temp * L_temp; |
| 617 | } |
| 618 | L_power <<= 1; /* from L_MULT */ |
| 619 | |
| 620 | /* Normalization of L_max and L_power |
| 621 | */ |
| 622 | |
| 623 | if (L_max <= 0) { |
| 624 | *bc_out = 0; |
| 625 | return; |
| 626 | } |
| 627 | if (L_max >= L_power) { |
| 628 | *bc_out = 3; |
| 629 | return; |
| 630 | } |
| 631 | |
| 632 | temp = gsm_norm( L_power ); |
| 633 | |
| 634 | R = SASR_L ( L_max << temp, 16 ); |
| 635 | S = SASR_L ( L_power << temp, 16 ); |
| 636 | |
| 637 | /* Coding of the LTP gain |
| 638 | */ |
| 639 | |
| 640 | /* Table 4.3a must be used to obtain the level DLB[i] for the |
| 641 | * quantization of the LTP gain b to get the coded version bc. |
| 642 | */ |
| 643 | for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break; |
| 644 | *bc_out = bc; |
| 645 | } |
| 646 | |
| 647 | #ifdef FAST |
| 648 | #ifdef LTP_CUT |
| 649 | |
| 650 | static void Cut_Fast_Calculation_of_the_LTP_parameters ( |
| 651 | struct gsm_state * st, /* IN */ |
| 652 | register word * d, /* [0..39] IN */ |
| 653 | register word * dp, /* [-120..-1] IN */ |
| 654 | word * bc_out, /* OUT */ |
| 655 | word * Nc_out /* OUT */ |
| 656 | ) |
| 657 | { |
| 658 | register int k, lambda; |
| 659 | register float wt_float; |
| 660 | word Nc, bc; |
| 661 | word wt_max, best_k, ltp_cut; |
| 662 | |
| 663 | float dp_float_base[120], * dp_float = dp_float_base + 120; |
| 664 | |
| 665 | register float L_result, L_max, L_power; |
| 666 | |
| 667 | wt_max = 0; |
| 668 | |
| 669 | for (k = 0; k < 40; ++k) { |
| 670 | if ( d[k] > wt_max) wt_max = d[best_k = k]; |
| 671 | else if (-d[k] > wt_max) wt_max = -d[best_k = k]; |
| 672 | } |
| 673 | |
| 674 | assert(wt_max >= 0); |
| 675 | wt_float = (float)wt_max; |
| 676 | |
| 677 | for (k = -120; k < 0; ++k) dp_float[k] = (float)dp[k]; |
| 678 | |
| 679 | /* Search for the maximum cross-correlation and coding of the LTP lag |
| 680 | */ |
| 681 | L_max = 0; |
| 682 | Nc = 40; /* index for the maximum cross-correlation */ |
| 683 | |
| 684 | for (lambda = 40; lambda <= 120; lambda++) { |
| 685 | L_result = wt_float * dp_float[best_k - lambda]; |
| 686 | if (L_result > L_max) { |
| 687 | Nc = lambda; |
| 688 | L_max = L_result; |
| 689 | } |
| 690 | } |
| 691 | |
| 692 | *Nc_out = Nc; |
| 693 | if (L_max <= 0.) { |
| 694 | *bc_out = 0; |
| 695 | return; |
| 696 | } |
| 697 | |
| 698 | /* Compute the power of the reconstructed short term residual |
| 699 | * signal dp[..] |
| 700 | */ |
| 701 | dp_float -= Nc; |
| 702 | L_power = 0; |
| 703 | for (k = 0; k < 40; ++k) { |
| 704 | register float f = dp_float[k]; |
| 705 | L_power += f * f; |
| 706 | } |
| 707 | |
| 708 | if (L_max >= L_power) { |
| 709 | *bc_out = 3; |
| 710 | return; |
| 711 | } |
| 712 | |
| 713 | /* Coding of the LTP gain |
| 714 | * Table 4.3a must be used to obtain the level DLB[i] for the |
| 715 | * quantization of the LTP gain b to get the coded version bc. |
| 716 | */ |
| 717 | lambda = L_max / L_power * 32768.; |
| 718 | for (bc = 0; bc <= 2; ++bc) if (lambda <= gsm_DLB[bc]) break; |
| 719 | *bc_out = bc; |
| 720 | } |
| 721 | |
| 722 | #endif /* LTP_CUT */ |
| 723 | |
| 724 | static void Fast_Calculation_of_the_LTP_parameters ( |
| 725 | register word * din, /* [0..39] IN */ |
| 726 | register word * dp, /* [-120..-1] IN */ |
| 727 | word * bc_out, /* OUT */ |
| 728 | word * Nc_out /* OUT */ |
| 729 | ) |
| 730 | { |
| 731 | register int k, lambda; |
| 732 | word Nc, bc; |
| 733 | |
| 734 | float wt_float[40]; |
| 735 | float dp_float_base[120], * dp_float = dp_float_base + 120; |
| 736 | |
| 737 | register float L_max, L_power; |
| 738 | |
| 739 | for (k = 0; k < 40; ++k) wt_float[k] = (float) din [k] ; |
| 740 | for (k = -120; k < 0; ++k) dp_float[k] = (float) dp [k] ; |
| 741 | |
| 742 | /* Search for the maximum cross-correlation and coding of the LTP lag |
| 743 | */ |
| 744 | L_max = 0; |
| 745 | Nc = 40; /* index for the maximum cross-correlation */ |
| 746 | |
| 747 | for (lambda = 40; lambda <= 120; lambda += 9) { |
| 748 | |
| 749 | /* Calculate L_result for l = lambda .. lambda + 9. |
| 750 | */ |
| 751 | register float *lp = dp_float - lambda; |
| 752 | |
| 753 | register float W; |
| 754 | register float a = lp[-8], b = lp[-7], c = lp[-6], |
| 755 | d = lp[-5], e = lp[-4], f = lp[-3], |
| 756 | g = lp[-2], h = lp[-1]; |
| 757 | register float E; |
| 758 | register float S0 = 0, S1 = 0, S2 = 0, S3 = 0, S4 = 0, |
| 759 | S5 = 0, S6 = 0, S7 = 0, S8 = 0; |
| 760 | |
| 761 | # undef STEP |
| 762 | # define STEP(K, a, b, c, d, e, f, g, h) \ |
| 763 | W = wt_float[K]; \ |
| 764 | E = W * a; S8 += E; \ |
| 765 | E = W * b; S7 += E; \ |
| 766 | E = W * c; S6 += E; \ |
| 767 | E = W * d; S5 += E; \ |
| 768 | E = W * e; S4 += E; \ |
| 769 | E = W * f; S3 += E; \ |
| 770 | E = W * g; S2 += E; \ |
| 771 | E = W * h; S1 += E; \ |
| 772 | a = lp[K]; \ |
| 773 | E = W * a; S0 += E |
| 774 | |
| 775 | # define STEP_A(K) STEP(K, a, b, c, d, e, f, g, h) |
| 776 | # define STEP_B(K) STEP(K, b, c, d, e, f, g, h, a) |
| 777 | # define STEP_C(K) STEP(K, c, d, e, f, g, h, a, b) |
| 778 | # define STEP_D(K) STEP(K, d, e, f, g, h, a, b, c) |
| 779 | # define STEP_E(K) STEP(K, e, f, g, h, a, b, c, d) |
| 780 | # define STEP_F(K) STEP(K, f, g, h, a, b, c, d, e) |
| 781 | # define STEP_G(K) STEP(K, g, h, a, b, c, d, e, f) |
| 782 | # define STEP_H(K) STEP(K, h, a, b, c, d, e, f, g) |
| 783 | |
| 784 | STEP_A( 0); STEP_B( 1); STEP_C( 2); STEP_D( 3); |
| 785 | STEP_E( 4); STEP_F( 5); STEP_G( 6); STEP_H( 7); |
| 786 | |
| 787 | STEP_A( 8); STEP_B( 9); STEP_C(10); STEP_D(11); |
| 788 | STEP_E(12); STEP_F(13); STEP_G(14); STEP_H(15); |
| 789 | |
| 790 | STEP_A(16); STEP_B(17); STEP_C(18); STEP_D(19); |
| 791 | STEP_E(20); STEP_F(21); STEP_G(22); STEP_H(23); |
| 792 | |
| 793 | STEP_A(24); STEP_B(25); STEP_C(26); STEP_D(27); |
| 794 | STEP_E(28); STEP_F(29); STEP_G(30); STEP_H(31); |
| 795 | |
| 796 | STEP_A(32); STEP_B(33); STEP_C(34); STEP_D(35); |
| 797 | STEP_E(36); STEP_F(37); STEP_G(38); STEP_H(39); |
| 798 | |
| 799 | if (S0 > L_max) { L_max = S0; Nc = lambda; } |
| 800 | if (S1 > L_max) { L_max = S1; Nc = lambda + 1; } |
| 801 | if (S2 > L_max) { L_max = S2; Nc = lambda + 2; } |
| 802 | if (S3 > L_max) { L_max = S3; Nc = lambda + 3; } |
| 803 | if (S4 > L_max) { L_max = S4; Nc = lambda + 4; } |
| 804 | if (S5 > L_max) { L_max = S5; Nc = lambda + 5; } |
| 805 | if (S6 > L_max) { L_max = S6; Nc = lambda + 6; } |
| 806 | if (S7 > L_max) { L_max = S7; Nc = lambda + 7; } |
| 807 | if (S8 > L_max) { L_max = S8; Nc = lambda + 8; } |
| 808 | } |
| 809 | *Nc_out = Nc; |
| 810 | |
| 811 | if (L_max <= 0.) { |
| 812 | *bc_out = 0; |
| 813 | return; |
| 814 | } |
| 815 | |
| 816 | /* Compute the power of the reconstructed short term residual |
| 817 | * signal dp[..] |
| 818 | */ |
| 819 | dp_float -= Nc; |
| 820 | L_power = 0; |
| 821 | for (k = 0; k < 40; ++k) { |
| 822 | register float f = dp_float[k]; |
| 823 | L_power += f * f; |
| 824 | } |
| 825 | |
| 826 | if (L_max >= L_power) { |
| 827 | *bc_out = 3; |
| 828 | return; |
| 829 | } |
| 830 | |
| 831 | /* Coding of the LTP gain |
| 832 | * Table 4.3a must be used to obtain the level DLB[i] for the |
| 833 | * quantization of the LTP gain b to get the coded version bc. |
| 834 | */ |
| 835 | lambda = L_max / L_power * 32768.; |
| 836 | for (bc = 0; bc <= 2; ++bc) if (lambda <= gsm_DLB[bc]) break; |
| 837 | *bc_out = bc; |
| 838 | } |
| 839 | |
| 840 | #endif /* FAST */ |
| 841 | #endif /* USE_FLOAT_MUL */ |
| 842 | |
| 843 | |
| 844 | /* 4.2.12 */ |
| 845 | |
| 846 | static void Long_term_analysis_filtering ( |
| 847 | word bc, /* IN */ |
| 848 | word Nc, /* IN */ |
| 849 | register word * dp, /* previous d [-120..-1] IN */ |
| 850 | register word * d, /* d [0..39] IN */ |
| 851 | register word * dpp, /* estimate [0..39] OUT */ |
| 852 | register word * e /* long term res. signal [0..39] OUT */ |
| 853 | ) |
| 854 | /* |
| 855 | * In this part, we have to decode the bc parameter to compute |
| 856 | * the samples of the estimate dpp[0..39]. The decoding of bc needs the |
| 857 | * use of table 4.3b. The long term residual signal e[0..39] |
| 858 | * is then calculated to be fed to the RPE encoding section. |
| 859 | */ |
| 860 | { |
| 861 | register int k; |
| 862 | |
| 863 | # undef STEP |
| 864 | # define STEP(BP) \ |
| 865 | for (k = 0; k <= 39; k++) { \ |
| 866 | dpp[k] = GSM_MULT_R( BP, dp[k - Nc]); \ |
| 867 | e[k] = GSM_SUB( d[k], dpp[k] ); \ |
| 868 | } |
| 869 | |
| 870 | switch (bc) { |
| 871 | case 0: STEP( 3277 ); break; |
| 872 | case 1: STEP( 11469 ); break; |
| 873 | case 2: STEP( 21299 ); break; |
| 874 | case 3: STEP( 32767 ); break; |
| 875 | } |
| 876 | } |
| 877 | |
| 878 | void Gsm_Long_Term_Predictor ( /* 4x for 160 samples */ |
| 879 | |
| 880 | struct gsm_state * S, |
| 881 | |
| 882 | word * d, /* [0..39] residual signal IN */ |
| 883 | word * dp, /* [-120..-1] d' IN */ |
| 884 | |
| 885 | word * e, /* [0..39] OUT */ |
| 886 | word * dpp, /* [0..39] OUT */ |
| 887 | word * Nc, /* correlation lag OUT */ |
| 888 | word * bc /* gain factor OUT */ |
| 889 | ) |
| 890 | { |
| 891 | assert( d ); assert( dp ); assert( e ); |
| 892 | assert( dpp); assert( Nc ); assert( bc ); |
| 893 | |
| 894 | #if defined(FAST) && defined(USE_FLOAT_MUL) |
| 895 | if (S->fast) |
| 896 | #if defined (LTP_CUT) |
| 897 | if (S->ltp_cut) |
| 898 | Cut_Fast_Calculation_of_the_LTP_parameters(S, |
| 899 | d, dp, bc, Nc); |
| 900 | else |
| 901 | #endif /* LTP_CUT */ |
| 902 | Fast_Calculation_of_the_LTP_parameters(d, dp, bc, Nc ); |
| 903 | else |
| 904 | #endif /* FAST & USE_FLOAT_MUL */ |
| 905 | #ifdef LTP_CUT |
| 906 | if (S->ltp_cut) |
| 907 | Cut_Calculation_of_the_LTP_parameters(S, d, dp, bc, Nc); |
| 908 | else |
| 909 | #endif |
| 910 | Calculation_of_the_LTP_parameters(d, dp, bc, Nc); |
| 911 | |
| 912 | Long_term_analysis_filtering( *bc, *Nc, dp, d, dpp, e ); |
| 913 | } |
| 914 | |
| 915 | /* 4.3.2 */ |
| 916 | void Gsm_Long_Term_Synthesis_Filtering ( |
| 917 | struct gsm_state * S, |
| 918 | |
| 919 | word Ncr, |
| 920 | word bcr, |
| 921 | register word * erp, /* [0..39] IN */ |
| 922 | register word * drp /* [-120..-1] IN, [-120..40] OUT */ |
| 923 | ) |
| 924 | /* |
| 925 | * This procedure uses the bcr and Ncr parameter to realize the |
| 926 | * long term synthesis filtering. The decoding of bcr needs |
| 927 | * table 4.3b. |
| 928 | */ |
| 929 | { |
| 930 | register int k; |
| 931 | word brp, drpp, Nr; |
| 932 | |
| 933 | /* Check the limits of Nr. |
| 934 | */ |
| 935 | Nr = Ncr < 40 || Ncr > 120 ? S->nrp : Ncr; |
| 936 | S->nrp = Nr; |
| 937 | assert(Nr >= 40 && Nr <= 120); |
| 938 | |
| 939 | /* Decoding of the LTP gain bcr |
| 940 | */ |
| 941 | brp = gsm_QLB[ bcr ]; |
| 942 | |
| 943 | /* Computation of the reconstructed short term residual |
| 944 | * signal drp[0..39] |
| 945 | */ |
| 946 | assert(brp != MIN_WORD); |
| 947 | |
| 948 | for (k = 0; k <= 39; k++) { |
| 949 | drpp = GSM_MULT_R( brp, drp[ k - Nr ] ); |
| 950 | drp[k] = GSM_ADD( erp[k], drpp ); |
| 951 | } |
| 952 | |
| 953 | /* |
| 954 | * Update of the reconstructed short term residual signal |
| 955 | * drp[ -1..-120 ] |
| 956 | */ |
| 957 | |
| 958 | for (k = 0; k <= 119; k++) drp[ -120 + k ] = drp[ -80 + k ]; |
| 959 | } |