1 /* Copyright (c) 2007-2008 CSIRO 2 Copyright (c) 2007-2009 Xiph.Org Foundation 3 Written by Jean-Marc Valin */ 4 /** 5 @file pitch.c 6 @brief Pitch analysis 7 */ 8 9 /* 10 Redistribution and use in source and binary forms, with or without 11 modification, are permitted provided that the following conditions 12 are met: 13 14 - Redistributions of source code must retain the above copyright 15 notice, this list of conditions and the following disclaimer. 16 17 - Redistributions in binary form must reproduce the above copyright 18 notice, this list of conditions and the following disclaimer in the 19 documentation and/or other materials provided with the distribution. 20 21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER 25 OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 26 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 27 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 28 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 29 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 30 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 31 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #ifdef HAVE_CONFIG_H 35 #include "config.h" 36 #endif 37 38 #include "pitch.h" 39 #include "os_support.h" 40 #include "modes.h" 41 #include "stack_alloc.h" 42 #include "mathops.h" 43 #include "celt_lpc.h" 44 45 static void find_best_pitch(opus_val32 *xcorr, opus_val16 *y, int len, 46 int max_pitch, int *best_pitch 47 #ifdef FIXED_POINT 48 , int yshift, opus_val32 maxcorr 49 #endif 50 ) 51 { 52 int i, j; 53 opus_val32 Syy=1; 54 opus_val16 best_num[2]; 55 opus_val32 best_den[2]; 56 #ifdef FIXED_POINT 57 int xshift; 58 59 xshift = celt_ilog2(maxcorr)-14; 60 #endif 61 62 best_num[0] = -1; 63 best_num[1] = -1; 64 best_den[0] = 0; 65 best_den[1] = 0; 66 best_pitch[0] = 0; 67 best_pitch[1] = 1; 68 for (j=0;j<len;j++) 69 Syy = ADD32(Syy, SHR32(MULT16_16(y[j],y[j]), yshift)); 70 for (i=0;i<max_pitch;i++) 71 { 72 if (xcorr[i]>0) 73 { 74 opus_val16 num; 75 opus_val32 xcorr16; 76 xcorr16 = EXTRACT16(VSHR32(xcorr[i], xshift)); 77 #ifndef FIXED_POINT 78 /* Considering the range of xcorr16, this should avoid both underflows 79 and overflows (inf) when squaring xcorr16 */ 80 xcorr16 *= 1e-12f; 81 #endif 82 num = MULT16_16_Q15(xcorr16,xcorr16); 83 if (MULT16_32_Q15(num,best_den[1]) > MULT16_32_Q15(best_num[1],Syy)) 84 { 85 if (MULT16_32_Q15(num,best_den[0]) > MULT16_32_Q15(best_num[0],Syy)) 86 { 87 best_num[1] = best_num[0]; 88 best_den[1] = best_den[0]; 89 best_pitch[1] = best_pitch[0]; 90 best_num[0] = num; 91 best_den[0] = Syy; 92 best_pitch[0] = i; 93 } else { 94 best_num[1] = num; 95 best_den[1] = Syy; 96 best_pitch[1] = i; 97 } 98 } 99 } 100 Syy += SHR32(MULT16_16(y[i+len],y[i+len]),yshift) - SHR32(MULT16_16(y[i],y[i]),yshift); 101 Syy = MAX32(1, Syy); 102 } 103 } 104 105 static void celt_fir5(const opus_val16 *x, 106 const opus_val16 *num, 107 opus_val16 *y, 108 int N, 109 opus_val16 *mem) 110 { 111 int i; 112 opus_val16 num0, num1, num2, num3, num4; 113 opus_val32 mem0, mem1, mem2, mem3, mem4; 114 num0=num[0]; 115 num1=num[1]; 116 num2=num[2]; 117 num3=num[3]; 118 num4=num[4]; 119 mem0=mem[0]; 120 mem1=mem[1]; 121 mem2=mem[2]; 122 mem3=mem[3]; 123 mem4=mem[4]; 124 for (i=0;i<N;i++) 125 { 126 opus_val32 sum = SHL32(EXTEND32(x[i]), SIG_SHIFT); 127 sum = MAC16_16(sum,num0,mem0); 128 sum = MAC16_16(sum,num1,mem1); 129 sum = MAC16_16(sum,num2,mem2); 130 sum = MAC16_16(sum,num3,mem3); 131 sum = MAC16_16(sum,num4,mem4); 132 mem4 = mem3; 133 mem3 = mem2; 134 mem2 = mem1; 135 mem1 = mem0; 136 mem0 = x[i]; 137 y[i] = ROUND16(sum, SIG_SHIFT); 138 } 139 mem[0]=mem0; 140 mem[1]=mem1; 141 mem[2]=mem2; 142 mem[3]=mem3; 143 mem[4]=mem4; 144 } 145 146 147 void pitch_downsample(celt_sig * OPUS_RESTRICT x[], opus_val16 * OPUS_RESTRICT x_lp, 148 int len, int C, int arch) 149 { 150 int i; 151 opus_val32 ac[5]; 152 opus_val16 tmp=Q15ONE; 153 opus_val16 lpc[4], mem[5]={0,0,0,0,0}; 154 opus_val16 lpc2[5]; 155 opus_val16 c1 = QCONST16(.8f,15); 156 #ifdef FIXED_POINT 157 int shift; 158 opus_val32 maxabs = celt_maxabs32(x[0], len); 159 if (C==2) 160 { 161 opus_val32 maxabs_1 = celt_maxabs32(x[1], len); 162 maxabs = MAX32(maxabs, maxabs_1); 163 } 164 if (maxabs<1) 165 maxabs=1; 166 shift = celt_ilog2(maxabs)-10; 167 if (shift<0) 168 shift=0; 169 if (C==2) 170 shift++; 171 #endif 172 for (i=1;i<len>>1;i++) 173 x_lp[i] = SHR32(HALF32(HALF32(x[0][(2*i-1)]+x[0][(2*i+1)])+x[0][2*i]), shift); 174 x_lp[0] = SHR32(HALF32(HALF32(x[0][1])+x[0][0]), shift); 175 if (C==2) 176 { 177 for (i=1;i<len>>1;i++) 178 x_lp[i] += SHR32(HALF32(HALF32(x[1][(2*i-1)]+x[1][(2*i+1)])+x[1][2*i]), shift); 179 x_lp[0] += SHR32(HALF32(HALF32(x[1][1])+x[1][0]), shift); 180 } 181 182 _celt_autocorr(x_lp, ac, NULL, 0, 183 4, len>>1, arch); 184 185 /* Noise floor -40 dB */ 186 #ifdef FIXED_POINT 187 ac[0] += SHR32(ac[0],13); 188 #else 189 ac[0] *= 1.0001f; 190 #endif 191 /* Lag windowing */ 192 for (i=1;i<=4;i++) 193 { 194 /*ac[i] *= exp(-.5*(2*M_PI*.002*i)*(2*M_PI*.002*i));*/ 195 #ifdef FIXED_POINT 196 ac[i] -= MULT16_32_Q15(2*i*i, ac[i]); 197 #else 198 ac[i] -= ac[i]*(.008f*i)*(.008f*i); 199 #endif 200 } 201 202 _celt_lpc(lpc, ac, 4); 203 for (i=0;i<4;i++) 204 { 205 tmp = MULT16_16_Q15(QCONST16(.9f,15), tmp); 206 lpc[i] = MULT16_16_Q15(lpc[i], tmp); 207 } 208 /* Add a zero */ 209 lpc2[0] = lpc[0] + QCONST16(.8f,SIG_SHIFT); 210 lpc2[1] = lpc[1] + MULT16_16_Q15(c1,lpc[0]); 211 lpc2[2] = lpc[2] + MULT16_16_Q15(c1,lpc[1]); 212 lpc2[3] = lpc[3] + MULT16_16_Q15(c1,lpc[2]); 213 lpc2[4] = MULT16_16_Q15(c1,lpc[3]); 214 celt_fir5(x_lp, lpc2, x_lp, len>>1, mem); 215 } 216 217 /* Pure C implementation. */ 218 #ifdef FIXED_POINT 219 opus_val32 220 #else 221 void 222 #endif 223 #if defined(OVERRIDE_PITCH_XCORR) 224 celt_pitch_xcorr_c(const opus_val16 *_x, const opus_val16 *_y, 225 opus_val32 *xcorr, int len, int max_pitch) 226 #else 227 celt_pitch_xcorr(const opus_val16 *_x, const opus_val16 *_y, 228 opus_val32 *xcorr, int len, int max_pitch, int arch) 229 #endif 230 { 231 232 #if 0 /* This is a simple version of the pitch correlation that should work 233 well on DSPs like Blackfin and TI C5x/C6x */ 234 int i, j; 235 #ifdef FIXED_POINT 236 opus_val32 maxcorr=1; 237 #endif 238 #if !defined(OVERRIDE_PITCH_XCORR) 239 (void)arch; 240 #endif 241 for (i=0;i<max_pitch;i++) 242 { 243 opus_val32 sum = 0; 244 for (j=0;j<len;j++) 245 sum = MAC16_16(sum, _x[j], _y[i+j]); 246 xcorr[i] = sum; 247 #ifdef FIXED_POINT 248 maxcorr = MAX32(maxcorr, sum); 249 #endif 250 } 251 #ifdef FIXED_POINT 252 return maxcorr; 253 #endif 254 255 #else /* Unrolled version of the pitch correlation -- runs faster on x86 and ARM */ 256 int i; 257 /*The EDSP version requires that max_pitch is at least 1, and that _x is 258 32-bit aligned. 259 Since it's hard to put asserts in assembly, put them here.*/ 260 #ifdef FIXED_POINT 261 opus_val32 maxcorr=1; 262 #endif 263 celt_assert(max_pitch>0); 264 celt_assert((((unsigned char *)_x-(unsigned char *)NULL)&3)==0); 265 for (i=0;i<max_pitch-3;i+=4) 266 { 267 opus_val32 sum[4]={0,0,0,0}; 268 #if defined(OVERRIDE_PITCH_XCORR) 269 xcorr_kernel_c(_x, _y+i, sum, len); 270 #else 271 xcorr_kernel(_x, _y+i, sum, len, arch); 272 #endif 273 xcorr[i]=sum[0]; 274 xcorr[i+1]=sum[1]; 275 xcorr[i+2]=sum[2]; 276 xcorr[i+3]=sum[3]; 277 #ifdef FIXED_POINT 278 sum[0] = MAX32(sum[0], sum[1]); 279 sum[2] = MAX32(sum[2], sum[3]); 280 sum[0] = MAX32(sum[0], sum[2]); 281 maxcorr = MAX32(maxcorr, sum[0]); 282 #endif 283 } 284 /* In case max_pitch isn't a multiple of 4, do non-unrolled version. */ 285 for (;i<max_pitch;i++) 286 { 287 opus_val32 sum; 288 #if defined(OVERRIDE_PITCH_XCORR) 289 sum = celt_inner_prod_c(_x, _y+i, len); 290 #else 291 sum = celt_inner_prod(_x, _y+i, len, arch); 292 #endif 293 xcorr[i] = sum; 294 #ifdef FIXED_POINT 295 maxcorr = MAX32(maxcorr, sum); 296 #endif 297 } 298 #ifdef FIXED_POINT 299 return maxcorr; 300 #endif 301 #endif 302 } 303 304 void pitch_search(const opus_val16 * OPUS_RESTRICT x_lp, opus_val16 * OPUS_RESTRICT y, 305 int len, int max_pitch, int *pitch, int arch) 306 { 307 int i, j; 308 int lag; 309 int best_pitch[2]={0,0}; 310 VARDECL(opus_val16, x_lp4); 311 VARDECL(opus_val16, y_lp4); 312 VARDECL(opus_val32, xcorr); 313 #ifdef FIXED_POINT 314 opus_val32 maxcorr; 315 opus_val32 xmax, ymax; 316 int shift=0; 317 #endif 318 int offset; 319 320 SAVE_STACK; 321 322 celt_assert(len>0); 323 celt_assert(max_pitch>0); 324 lag = len+max_pitch; 325 326 ALLOC(x_lp4, len>>2, opus_val16); 327 ALLOC(y_lp4, lag>>2, opus_val16); 328 ALLOC(xcorr, max_pitch>>1, opus_val32); 329 330 /* Downsample by 2 again */ 331 for (j=0;j<len>>2;j++) 332 x_lp4[j] = x_lp[2*j]; 333 for (j=0;j<lag>>2;j++) 334 y_lp4[j] = y[2*j]; 335 336 #ifdef FIXED_POINT 337 xmax = celt_maxabs16(x_lp4, len>>2); 338 ymax = celt_maxabs16(y_lp4, lag>>2); 339 shift = celt_ilog2(MAX32(1, MAX32(xmax, ymax)))-11; 340 if (shift>0) 341 { 342 for (j=0;j<len>>2;j++) 343 x_lp4[j] = SHR16(x_lp4[j], shift); 344 for (j=0;j<lag>>2;j++) 345 y_lp4[j] = SHR16(y_lp4[j], shift); 346 /* Use double the shift for a MAC */ 347 shift *= 2; 348 } else { 349 shift = 0; 350 } 351 #endif 352 353 /* Coarse search with 4x decimation */ 354 355 #ifdef FIXED_POINT 356 maxcorr = 357 #endif 358 celt_pitch_xcorr(x_lp4, y_lp4, xcorr, len>>2, max_pitch>>2, arch); 359 360 find_best_pitch(xcorr, y_lp4, len>>2, max_pitch>>2, best_pitch 361 #ifdef FIXED_POINT 362 , 0, maxcorr 363 #endif 364 ); 365 366 /* Finer search with 2x decimation */ 367 #ifdef FIXED_POINT 368 maxcorr=1; 369 #endif 370 for (i=0;i<max_pitch>>1;i++) 371 { 372 opus_val32 sum; 373 xcorr[i] = 0; 374 if (abs(i-2*best_pitch[0])>2 && abs(i-2*best_pitch[1])>2) 375 continue; 376 #ifdef FIXED_POINT 377 sum = 0; 378 for (j=0;j<len>>1;j++) 379 sum += SHR32(MULT16_16(x_lp[j],y[i+j]), shift); 380 #else 381 sum = celt_inner_prod_c(x_lp, y+i, len>>1); 382 #endif 383 xcorr[i] = MAX32(-1, sum); 384 #ifdef FIXED_POINT 385 maxcorr = MAX32(maxcorr, sum); 386 #endif 387 } 388 find_best_pitch(xcorr, y, len>>1, max_pitch>>1, best_pitch 389 #ifdef FIXED_POINT 390 , shift+1, maxcorr 391 #endif 392 ); 393 394 /* Refine by pseudo-interpolation */ 395 if (best_pitch[0]>0 && best_pitch[0]<(max_pitch>>1)-1) 396 { 397 opus_val32 a, b, c; 398 a = xcorr[best_pitch[0]-1]; 399 b = xcorr[best_pitch[0]]; 400 c = xcorr[best_pitch[0]+1]; 401 if ((c-a) > MULT16_32_Q15(QCONST16(.7f,15),b-a)) 402 offset = 1; 403 else if ((a-c) > MULT16_32_Q15(QCONST16(.7f,15),b-c)) 404 offset = -1; 405 else 406 offset = 0; 407 } else { 408 offset = 0; 409 } 410 *pitch = 2*best_pitch[0]-offset; 411 412 RESTORE_STACK; 413 } 414 415 #ifdef FIXED_POINT 416 static opus_val16 compute_pitch_gain(opus_val32 xy, opus_val32 xx, opus_val32 yy) 417 { 418 opus_val32 x2y2; 419 int sx, sy, shift; 420 opus_val32 g; 421 opus_val16 den; 422 if (xy == 0 || xx == 0 || yy == 0) 423 return 0; 424 sx = celt_ilog2(xx)-14; 425 sy = celt_ilog2(yy)-14; 426 shift = sx + sy; 427 x2y2 = MULT16_16_Q14(VSHR32(xx, sx), VSHR32(yy, sy)); 428 if (shift & 1) { 429 if (x2y2 < 32768) 430 { 431 x2y2 <<= 1; 432 shift--; 433 } else { 434 x2y2 >>= 1; 435 shift++; 436 } 437 } 438 den = celt_rsqrt_norm(x2y2); 439 g = MULT16_32_Q15(den, xy); 440 g = VSHR32(g, (shift>>1)-1); 441 return EXTRACT16(MIN32(g, Q15ONE)); 442 } 443 #else 444 static opus_val16 compute_pitch_gain(opus_val32 xy, opus_val32 xx, opus_val32 yy) 445 { 446 return xy/celt_sqrt(1+xx*yy); 447 } 448 #endif 449 450 static const int second_check[16] = {0, 0, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2}; 451 opus_val16 remove_doubling(opus_val16 *x, int maxperiod, int minperiod, 452 int N, int *T0_, int prev_period, opus_val16 prev_gain, int arch) 453 { 454 int k, i, T, T0; 455 opus_val16 g, g0; 456 opus_val16 pg; 457 opus_val32 xy,xx,yy,xy2; 458 opus_val32 xcorr[3]; 459 opus_val32 best_xy, best_yy; 460 int offset; 461 int minperiod0; 462 VARDECL(opus_val32, yy_lookup); 463 SAVE_STACK; 464 465 minperiod0 = minperiod; 466 maxperiod /= 2; 467 minperiod /= 2; 468 *T0_ /= 2; 469 prev_period /= 2; 470 N /= 2; 471 x += maxperiod; 472 if (*T0_>=maxperiod) 473 *T0_=maxperiod-1; 474 475 T = T0 = *T0_; 476 ALLOC(yy_lookup, maxperiod+1, opus_val32); 477 dual_inner_prod(x, x, x-T0, N, &xx, &xy, arch); 478 yy_lookup[0] = xx; 479 yy=xx; 480 for (i=1;i<=maxperiod;i++) 481 { 482 yy = yy+MULT16_16(x[-i],x[-i])-MULT16_16(x[N-i],x[N-i]); 483 yy_lookup[i] = MAX32(0, yy); 484 } 485 yy = yy_lookup[T0]; 486 best_xy = xy; 487 best_yy = yy; 488 g = g0 = compute_pitch_gain(xy, xx, yy); 489 /* Look for any pitch at T/k */ 490 for (k=2;k<=15;k++) 491 { 492 int T1, T1b; 493 opus_val16 g1; 494 opus_val16 cont=0; 495 opus_val16 thresh; 496 T1 = celt_udiv(2*T0+k, 2*k); 497 if (T1 < minperiod) 498 break; 499 /* Look for another strong correlation at T1b */ 500 if (k==2) 501 { 502 if (T1+T0>maxperiod) 503 T1b = T0; 504 else 505 T1b = T0+T1; 506 } else 507 { 508 T1b = celt_udiv(2*second_check[k]*T0+k, 2*k); 509 } 510 dual_inner_prod(x, &x[-T1], &x[-T1b], N, &xy, &xy2, arch); 511 xy = HALF32(xy + xy2); 512 yy = HALF32(yy_lookup[T1] + yy_lookup[T1b]); 513 g1 = compute_pitch_gain(xy, xx, yy); 514 if (abs(T1-prev_period)<=1) 515 cont = prev_gain; 516 else if (abs(T1-prev_period)<=2 && 5*k*k < T0) 517 cont = HALF16(prev_gain); 518 else 519 cont = 0; 520 thresh = MAX16(QCONST16(.3f,15), MULT16_16_Q15(QCONST16(.7f,15),g0)-cont); 521 /* Bias against very high pitch (very short period) to avoid false-positives 522 due to short-term correlation */ 523 if (T1<3*minperiod) 524 thresh = MAX16(QCONST16(.4f,15), MULT16_16_Q15(QCONST16(.85f,15),g0)-cont); 525 else if (T1<2*minperiod) 526 thresh = MAX16(QCONST16(.5f,15), MULT16_16_Q15(QCONST16(.9f,15),g0)-cont); 527 if (g1 > thresh) 528 { 529 best_xy = xy; 530 best_yy = yy; 531 T = T1; 532 g = g1; 533 } 534 } 535 best_xy = MAX32(0, best_xy); 536 if (best_yy <= best_xy) 537 pg = Q15ONE; 538 else 539 pg = SHR32(frac_div32(best_xy,best_yy+1),16); 540 541 for (k=0;k<3;k++) 542 xcorr[k] = celt_inner_prod(x, x-(T+k-1), N, arch); 543 if ((xcorr[2]-xcorr[0]) > MULT16_32_Q15(QCONST16(.7f,15),xcorr[1]-xcorr[0])) 544 offset = 1; 545 else if ((xcorr[0]-xcorr[2]) > MULT16_32_Q15(QCONST16(.7f,15),xcorr[1]-xcorr[2])) 546 offset = -1; 547 else 548 offset = 0; 549 if (pg > g) 550 pg = g; 551 *T0_ = 2*T+offset; 552 553 if (*T0_<minperiod0) 554 *T0_=minperiod0; 555 RESTORE_STACK; 556 return pg; 557 } 558
