pitch_f4.c revision e2e838afcf03e603a41a0455846eaf9614537c16
1/* 2 ** Copyright 2003-2010, VisualOn, Inc. 3 ** 4 ** Licensed under the Apache License, Version 2.0 (the "License"); 5 ** you may not use this file except in compliance with the License. 6 ** You may obtain a copy of the License at 7 ** 8 ** http://www.apache.org/licenses/LICENSE-2.0 9 ** 10 ** Unless required by applicable law or agreed to in writing, software 11 ** distributed under the License is distributed on an "AS IS" BASIS, 12 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 ** See the License for the specific language governing permissions and 14 ** limitations under the License. 15 */ 16 17/*********************************************************************** 18* File: pitch_f4.c * 19* * 20* Description: Find the closed loop pitch period with * 21* 1/4 subsample resolution. * 22* * 23************************************************************************/ 24 25#include "typedef.h" 26#include "basic_op.h" 27#include "math_op.h" 28#include "acelp.h" 29#include "cnst.h" 30 31#define UP_SAMP 4 32#define L_INTERPOL1 4 33 34/* Local functions */ 35 36#ifdef ASM_OPT 37void Norm_corr_asm( 38 Word16 exc[], /* (i) : excitation buffer */ 39 Word16 xn[], /* (i) : target vector */ 40 Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */ 41 Word16 L_subfr, 42 Word16 t_min, /* (i) : minimum value of pitch lag. */ 43 Word16 t_max, /* (i) : maximum value of pitch lag. */ 44 Word16 corr_norm[] /* (o) Q15 : normalized correlation */ 45 ); 46#else 47static void Norm_Corr( 48 Word16 exc[], /* (i) : excitation buffer */ 49 Word16 xn[], /* (i) : target vector */ 50 Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */ 51 Word16 L_subfr, 52 Word16 t_min, /* (i) : minimum value of pitch lag. */ 53 Word16 t_max, /* (i) : maximum value of pitch lag. */ 54 Word16 corr_norm[] /* (o) Q15 : normalized correlation */ 55 ); 56#endif 57 58static Word16 Interpol_4( /* (o) : interpolated value */ 59 Word16 * x, /* (i) : input vector */ 60 Word32 frac /* (i) : fraction (-4..+3) */ 61 ); 62 63 64Word16 Pitch_fr4( /* (o) : pitch period. */ 65 Word16 exc[], /* (i) : excitation buffer */ 66 Word16 xn[], /* (i) : target vector */ 67 Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */ 68 Word16 t0_min, /* (i) : minimum value in the searched range. */ 69 Word16 t0_max, /* (i) : maximum value in the searched range. */ 70 Word16 * pit_frac, /* (o) : chosen fraction (0, 1, 2 or 3). */ 71 Word16 i_subfr, /* (i) : indicator for first subframe. */ 72 Word16 t0_fr2, /* (i) : minimum value for resolution 1/2 */ 73 Word16 t0_fr1, /* (i) : minimum value for resolution 1 */ 74 Word16 L_subfr /* (i) : Length of subframe */ 75 ) 76{ 77 Word32 fraction, i; 78 Word16 t_min, t_max; 79 Word16 max, t0, step, temp; 80 Word16 *corr; 81 Word16 corr_v[40]; /* Total length = t0_max-t0_min+1+2*L_inter */ 82 83 /* Find interval to compute normalized correlation */ 84 85 t_min = t0_min - L_INTERPOL1; 86 t_max = t0_max + L_INTERPOL1; 87 corr = &corr_v[-t_min]; 88 /* Compute normalized correlation between target and filtered excitation */ 89#ifdef ASM_OPT /* asm optimization branch */ 90 Norm_corr_asm(exc, xn, h, L_subfr, t_min, t_max, corr); 91#else 92 Norm_Corr(exc, xn, h, L_subfr, t_min, t_max, corr); 93#endif 94 95 /* Find integer pitch */ 96 97 max = corr[t0_min]; 98 t0 = t0_min; 99 for (i = t0_min + 1; i <= t0_max; i++) 100 { 101 if (corr[i] >= max) 102 { 103 max = corr[i]; 104 t0 = i; 105 } 106 } 107 /* If first subframe and t0 >= t0_fr1, do not search fractionnal pitch */ 108 if ((i_subfr == 0) && (t0 >= t0_fr1)) 109 { 110 *pit_frac = 0; 111 return (t0); 112 } 113 /*------------------------------------------------------------------* 114 * Search fractionnal pitch with 1/4 subsample resolution. * 115 * Test the fractions around t0 and choose the one which maximizes * 116 * the interpolated normalized correlation. * 117 *------------------------------------------------------------------*/ 118 119 step = 1; /* 1/4 subsample resolution */ 120 fraction = -3; 121 if ((t0_fr2 == PIT_MIN)||((i_subfr == 0) && (t0 >= t0_fr2))) 122 { 123 step = 2; /* 1/2 subsample resolution */ 124 fraction = -2; 125 } 126 if(t0 == t0_min) 127 { 128 fraction = 0; 129 } 130 max = Interpol_4(&corr[t0], fraction); 131 132 for (i = fraction + step; i <= 3; i += step) 133 { 134 temp = Interpol_4(&corr[t0], i); 135 if(temp > max) 136 { 137 max = temp; 138 fraction = i; 139 } 140 } 141 /* limit the fraction value in the interval [0,1,2,3] */ 142 if (fraction < 0) 143 { 144 fraction += UP_SAMP; 145 t0 -= 1; 146 } 147 *pit_frac = fraction; 148 return (t0); 149} 150 151 152/*********************************************************************************** 153* Function: Norm_Corr() * 154* * 155* Description: Find the normalized correlation between the target vector and the * 156* filtered past excitation. * 157* (correlation between target and filtered excitation divided by the * 158* square root of energy of target and filtered excitation). * 159************************************************************************************/ 160#ifndef ASM_OPT 161static void Norm_Corr( 162 Word16 exc[], /* (i) : excitation buffer */ 163 Word16 xn[], /* (i) : target vector */ 164 Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */ 165 Word16 L_subfr, 166 Word16 t_min, /* (i) : minimum value of pitch lag. */ 167 Word16 t_max, /* (i) : maximum value of pitch lag. */ 168 Word16 corr_norm[]) /* (o) Q15 : normalized correlation */ 169{ 170 Word32 i, k, t; 171 Word32 corr, exp_corr, norm, exp, scale; 172 Word16 exp_norm, excf[L_SUBFR], tmp; 173 Word32 L_tmp, L_tmp1, L_tmp2; 174 175 /* compute the filtered excitation for the first delay t_min */ 176 k = -t_min; 177 178#ifdef ASM_OPT /* asm optimization branch */ 179 Convolve_asm(&exc[k], h, excf, 64); 180#else 181 Convolve(&exc[k], h, excf, 64); 182#endif 183 184 /* Compute rounded down 1/sqrt(energy of xn[]) */ 185 L_tmp = 0; 186 for (i = 0; i < 64; i+=4) 187 { 188 L_tmp += (xn[i] * xn[i]); 189 L_tmp += (xn[i+1] * xn[i+1]); 190 L_tmp += (xn[i+2] * xn[i+2]); 191 L_tmp += (xn[i+3] * xn[i+3]); 192 } 193 194 L_tmp = (L_tmp << 1) + 1; 195 exp = norm_l(L_tmp); 196 exp = (32 - exp); 197 //exp = exp + 2; /* energy of xn[] x 2 + rounded up */ 198 scale = -(exp >> 1); /* (1<<scale) < 1/sqrt(energy rounded) */ 199 200 /* loop for every possible period */ 201 202 for (t = t_min; t <= t_max; t++) 203 { 204 /* Compute correlation between xn[] and excf[] */ 205 L_tmp = 0; 206 L_tmp1 = 0; 207 for (i = 0; i < 64; i+=4) 208 { 209 L_tmp += (xn[i] * excf[i]); 210 L_tmp1 += (excf[i] * excf[i]); 211 L_tmp += (xn[i+1] * excf[i+1]); 212 L_tmp1 += (excf[i+1] * excf[i+1]); 213 L_tmp += (xn[i+2] * excf[i+2]); 214 L_tmp1 += (excf[i+2] * excf[i+2]); 215 L_tmp += (xn[i+3] * excf[i+3]); 216 L_tmp1 += (excf[i+3] * excf[i+3]); 217 } 218 219 L_tmp = (L_tmp << 1) + 1; 220 L_tmp1 = (L_tmp1 << 1) + 1; 221 222 exp = norm_l(L_tmp); 223 L_tmp = (L_tmp << exp); 224 exp_corr = (30 - exp); 225 corr = extract_h(L_tmp); 226 227 exp = norm_l(L_tmp1); 228 L_tmp = (L_tmp1 << exp); 229 exp_norm = (30 - exp); 230 231 Isqrt_n(&L_tmp, &exp_norm); 232 norm = extract_h(L_tmp); 233 234 /* Normalize correlation = correlation * (1/sqrt(energy)) */ 235 236 L_tmp = vo_L_mult(corr, norm); 237 238 L_tmp2 = exp_corr + exp_norm + scale; 239 if(L_tmp2 < 0) 240 { 241 L_tmp2 = -L_tmp2; 242 L_tmp = L_tmp >> L_tmp2; 243 } 244 else 245 { 246 L_tmp = L_tmp << L_tmp2; 247 } 248 249 corr_norm[t] = vo_round(L_tmp); 250 /* modify the filtered excitation excf[] for the next iteration */ 251 252 if(t != t_max) 253 { 254 k = -(t + 1); 255 tmp = exc[k]; 256 for (i = 63; i > 0; i--) 257 { 258 excf[i] = add1(vo_mult(tmp, h[i]), excf[i - 1]); 259 } 260 excf[0] = vo_mult(tmp, h[0]); 261 } 262 } 263 return; 264} 265 266#endif 267/************************************************************************************ 268* Function: Interpol_4() * 269* * 270* Description: For interpolating the normalized correlation with 1/4 resolution. * 271**************************************************************************************/ 272 273/* 1/4 resolution interpolation filter (-3 dB at 0.791*fs/2) in Q14 */ 274static Word16 inter4_1[4][8] = 275{ 276 {-12, 420, -1732, 5429, 13418, -1242, 73, 32}, 277 {-26, 455, -2142, 9910, 9910, -2142, 455, -26}, 278 {32, 73, -1242, 13418, 5429, -1732, 420, -12}, 279 {206, -766, 1376, 14746, 1376, -766, 206, 0} 280}; 281 282/*** Coefficients in floating point 283static float inter4_1[UP_SAMP*L_INTERPOL1+1] = { 2840.900000, 2850.818959, 0.604850, 0.331379, 0.083958, 286-0.075795, -0.130717, -0.105685, -0.046774, 2870.004467, 0.027789, 0.025642, 0.012571, 2880.001927, -0.001571, -0.000753, 0.000000}; 289***/ 290 291static Word16 Interpol_4( /* (o) : interpolated value */ 292 Word16 * x, /* (i) : input vector */ 293 Word32 frac /* (i) : fraction (-4..+3) */ 294 ) 295{ 296 Word16 sum; 297 Word32 k, L_sum; 298 Word16 *ptr; 299 300 if (frac < 0) 301 { 302 frac += UP_SAMP; 303 x--; 304 } 305 x = x - L_INTERPOL1 + 1; 306 k = UP_SAMP - 1 - frac; 307 ptr = &(inter4_1[k][0]); 308 309 L_sum = vo_mult32(x[0], (*ptr++)); 310 L_sum += vo_mult32(x[1], (*ptr++)); 311 L_sum += vo_mult32(x[2], (*ptr++)); 312 L_sum += vo_mult32(x[3], (*ptr++)); 313 L_sum += vo_mult32(x[4], (*ptr++)); 314 L_sum += vo_mult32(x[5], (*ptr++)); 315 L_sum += vo_mult32(x[6], (*ptr++)); 316 L_sum += vo_mult32(x[7], (*ptr++)); 317 318 sum = extract_h(L_add(L_shl2(L_sum, 2), 0x8000)); 319 return (sum); 320} 321 322 323 324 325