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 #define UNUSED(x) (void)(x) 35 36 /* Local functions */ 37 38 #ifdef ASM_OPT 39 void Norm_corr_asm( 40 Word16 exc[], /* (i) : excitation buffer */ 41 Word16 xn[], /* (i) : target vector */ 42 Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */ 43 Word16 L_subfr, 44 Word16 t_min, /* (i) : minimum value of pitch lag. */ 45 Word16 t_max, /* (i) : maximum value of pitch lag. */ 46 Word16 corr_norm[] /* (o) Q15 : normalized correlation */ 47 ); 48 #else 49 static void Norm_Corr( 50 Word16 exc[], /* (i) : excitation buffer */ 51 Word16 xn[], /* (i) : target vector */ 52 Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */ 53 Word16 L_subfr, 54 Word16 t_min, /* (i) : minimum value of pitch lag. */ 55 Word16 t_max, /* (i) : maximum value of pitch lag. */ 56 Word16 corr_norm[] /* (o) Q15 : normalized correlation */ 57 ); 58 #endif 59 60 static Word16 Interpol_4( /* (o) : interpolated value */ 61 Word16 * x, /* (i) : input vector */ 62 Word32 frac /* (i) : fraction (-4..+3) */ 63 ); 64 65 66 Word16 Pitch_fr4( /* (o) : pitch period. */ 67 Word16 exc[], /* (i) : excitation buffer */ 68 Word16 xn[], /* (i) : target vector */ 69 Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */ 70 Word16 t0_min, /* (i) : minimum value in the searched range. */ 71 Word16 t0_max, /* (i) : maximum value in the searched range. */ 72 Word16 * pit_frac, /* (o) : chosen fraction (0, 1, 2 or 3). */ 73 Word16 i_subfr, /* (i) : indicator for first subframe. */ 74 Word16 t0_fr2, /* (i) : minimum value for resolution 1/2 */ 75 Word16 t0_fr1, /* (i) : minimum value for resolution 1 */ 76 Word16 L_subfr /* (i) : Length of subframe */ 77 ) 78 { 79 Word32 fraction, i; 80 Word16 t_min, t_max; 81 Word16 max, t0, step, temp; 82 Word16 *corr; 83 Word16 corr_v[40]; /* Total length = t0_max-t0_min+1+2*L_inter */ 84 85 /* Find interval to compute normalized correlation */ 86 87 t_min = L_sub(t0_min, L_INTERPOL1); 88 t_max = L_add(t0_max, L_INTERPOL1); 89 corr = &corr_v[-t_min]; 90 /* Compute normalized correlation between target and filtered excitation */ 91 #ifdef ASM_OPT /* asm optimization branch */ 92 Norm_corr_asm(exc, xn, h, L_subfr, t_min, t_max, corr); 93 #else 94 Norm_Corr(exc, xn, h, L_subfr, t_min, t_max, corr); 95 #endif 96 97 /* Find integer pitch */ 98 99 max = corr[t0_min]; 100 t0 = t0_min; 101 for (i = t0_min + 1; i <= t0_max; i++) 102 { 103 if (corr[i] >= max) 104 { 105 max = corr[i]; 106 t0 = i; 107 } 108 } 109 /* If first subframe and t0 >= t0_fr1, do not search fractionnal pitch */ 110 if ((i_subfr == 0) && (t0 >= t0_fr1)) 111 { 112 *pit_frac = 0; 113 return (t0); 114 } 115 /*------------------------------------------------------------------* 116 * Search fractionnal pitch with 1/4 subsample resolution. * 117 * Test the fractions around t0 and choose the one which maximizes * 118 * the interpolated normalized correlation. * 119 *------------------------------------------------------------------*/ 120 121 step = 1; /* 1/4 subsample resolution */ 122 fraction = -3; 123 if ((t0_fr2 == PIT_MIN)||((i_subfr == 0) && (t0 >= t0_fr2))) 124 { 125 step = 2; /* 1/2 subsample resolution */ 126 fraction = -2; 127 } 128 if(t0 == t0_min) 129 { 130 fraction = 0; 131 } 132 max = Interpol_4(&corr[t0], fraction); 133 134 for (i = fraction + step; i <= 3; i += step) 135 { 136 temp = Interpol_4(&corr[t0], i); 137 if(temp > max) 138 { 139 max = temp; 140 fraction = i; 141 } 142 } 143 /* limit the fraction value in the interval [0,1,2,3] */ 144 if (fraction < 0) 145 { 146 fraction += UP_SAMP; 147 t0 -= 1; 148 } 149 *pit_frac = fraction; 150 return (t0); 151 } 152 153 154 /*********************************************************************************** 155 * Function: Norm_Corr() * 156 * * 157 * Description: Find the normalized correlation between the target vector and the * 158 * filtered past excitation. * 159 * (correlation between target and filtered excitation divided by the * 160 * square root of energy of target and filtered excitation). * 161 ************************************************************************************/ 162 #ifndef ASM_OPT 163 static void Norm_Corr( 164 Word16 exc[], /* (i) : excitation buffer */ 165 Word16 xn[], /* (i) : target vector */ 166 Word16 h[], /* (i) Q15 : impulse response of synth/wgt filters */ 167 Word16 L_subfr, 168 Word16 t_min, /* (i) : minimum value of pitch lag. */ 169 Word16 t_max, /* (i) : maximum value of pitch lag. */ 170 Word16 corr_norm[]) /* (o) Q15 : normalized correlation */ 171 { 172 Word32 i, k, t; 173 Word32 corr, exp_corr, norm, exp, scale; 174 Word16 exp_norm, excf[L_SUBFR], tmp; 175 Word32 L_tmp, L_tmp1, L_tmp2; 176 UNUSED(L_subfr); 177 178 /* compute the filtered excitation for the first delay t_min */ 179 k = -t_min; 180 181 #ifdef ASM_OPT /* asm optimization branch */ 182 Convolve_asm(&exc[k], h, excf, 64); 183 #else 184 Convolve(&exc[k], h, excf, 64); 185 #endif 186 187 /* Compute rounded down 1/sqrt(energy of xn[]) */ 188 L_tmp = 0; 189 for (i = 0; i < 64; i+=4) 190 { 191 L_tmp = L_add(L_tmp, (xn[i] * xn[i])); 192 L_tmp = L_add(L_tmp, (xn[i+1] * xn[i+1])); 193 L_tmp = L_add(L_tmp, (xn[i+2] * xn[i+2])); 194 L_tmp = L_add(L_tmp, (xn[i+3] * xn[i+3])); 195 } 196 197 L_tmp = L_add(L_shl(L_tmp, 1), 1); 198 exp = norm_l(L_tmp); 199 exp = L_sub(32, exp); 200 //exp = exp + 2; /* energy of xn[] x 2 + rounded up */ 201 scale = -(exp >> 1); /* (1<<scale) < 1/sqrt(energy rounded) */ 202 203 /* loop for every possible period */ 204 205 for (t = t_min; t <= t_max; t++) 206 { 207 /* Compute correlation between xn[] and excf[] */ 208 L_tmp = 0; 209 L_tmp1 = 0; 210 for (i = 0; i < 64; i+=4) 211 { 212 L_tmp = L_add(L_tmp, (xn[i] * excf[i])); 213 L_tmp1 = L_add(L_tmp1, (excf[i] * excf[i])); 214 L_tmp = L_add(L_tmp, (xn[i+1] * excf[i+1])); 215 L_tmp1 = L_add(L_tmp1, (excf[i+1] * excf[i+1])); 216 L_tmp = L_add(L_tmp, (xn[i+2] * excf[i+2])); 217 L_tmp1 = L_add(L_tmp1, (excf[i+2] * excf[i+2])); 218 L_tmp = L_add(L_tmp, (xn[i+3] * excf[i+3])); 219 L_tmp1 = L_add(L_tmp1, (excf[i+3] * excf[i+3])); 220 } 221 222 L_tmp = L_add(L_shl(L_tmp, 1), 1); 223 L_tmp1 = L_add(L_shl(L_tmp1, 1), 1); 224 225 exp = norm_l(L_tmp); 226 L_tmp = L_shl(L_tmp, exp); 227 exp_corr = L_sub(30, exp); 228 corr = extract_h(L_tmp); 229 230 exp = norm_l(L_tmp1); 231 L_tmp = L_shl(L_tmp1, exp); 232 exp_norm = L_sub(30, exp); 233 234 Isqrt_n(&L_tmp, &exp_norm); 235 norm = extract_h(L_tmp); 236 237 /* Normalize correlation = correlation * (1/sqrt(energy)) */ 238 239 L_tmp = L_mult(corr, norm); 240 241 L_tmp2 = L_add(exp_corr, exp_norm + scale); 242 if(L_tmp2 < 0) 243 { 244 L_tmp2 = -L_tmp2; 245 L_tmp = L_tmp >> L_tmp2; 246 } 247 else 248 { 249 L_tmp = L_shl(L_tmp, L_tmp2); 250 } 251 252 corr_norm[t] = voround(L_tmp); 253 /* modify the filtered excitation excf[] for the next iteration */ 254 255 if(t != t_max) 256 { 257 k = -(t + 1); 258 tmp = exc[k]; 259 for (i = 63; i > 0; i--) 260 { 261 excf[i] = add1(vo_mult(tmp, h[i]), excf[i - 1]); 262 } 263 excf[0] = vo_mult(tmp, h[0]); 264 } 265 } 266 return; 267 } 268 269 #endif 270 /************************************************************************************ 271 * Function: Interpol_4() * 272 * * 273 * Description: For interpolating the normalized correlation with 1/4 resolution. * 274 **************************************************************************************/ 275 276 /* 1/4 resolution interpolation filter (-3 dB at 0.791*fs/2) in Q14 */ 277 static Word16 inter4_1[4][8] = 278 { 279 {-12, 420, -1732, 5429, 13418, -1242, 73, 32}, 280 {-26, 455, -2142, 9910, 9910, -2142, 455, -26}, 281 {32, 73, -1242, 13418, 5429, -1732, 420, -12}, 282 {206, -766, 1376, 14746, 1376, -766, 206, 0} 283 }; 284 285 /*** Coefficients in floating point 286 static float inter4_1[UP_SAMP*L_INTERPOL1+1] = { 287 0.900000, 288 0.818959, 0.604850, 0.331379, 0.083958, 289 -0.075795, -0.130717, -0.105685, -0.046774, 290 0.004467, 0.027789, 0.025642, 0.012571, 291 0.001927, -0.001571, -0.000753, 0.000000}; 292 ***/ 293 294 static Word16 Interpol_4( /* (o) : interpolated value */ 295 Word16 * x, /* (i) : input vector */ 296 Word32 frac /* (i) : fraction (-4..+3) */ 297 ) 298 { 299 Word16 sum; 300 Word32 k, L_sum; 301 Word16 *ptr; 302 303 if (frac < 0) 304 { 305 frac += UP_SAMP; 306 x--; 307 } 308 x = x - L_INTERPOL1 + 1; 309 k = UP_SAMP - 1 - frac; 310 ptr = &(inter4_1[k][0]); 311 312 L_sum = vo_mult32(x[0], (*ptr++)); 313 L_sum = L_add(L_sum, vo_mult32(x[1], (*ptr++))); 314 L_sum = L_add(L_sum, vo_mult32(x[2], (*ptr++))); 315 L_sum = L_add(L_sum, vo_mult32(x[3], (*ptr++))); 316 L_sum = L_add(L_sum, vo_mult32(x[4], (*ptr++))); 317 L_sum = L_add(L_sum, vo_mult32(x[5], (*ptr++))); 318 L_sum = L_add(L_sum, vo_mult32(x[6], (*ptr++))); 319 L_sum = L_add(L_sum, vo_mult32(x[7], (*ptr++))); 320 321 sum = extract_h(L_add(L_shl2(L_sum, 2), 0x8000)); 322 return (sum); 323 } 324 325 326 327 328
