1 /* ------------------------------------------------------------------ 2 * Copyright (C) 1998-2009 PacketVideo 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 13 * express or implied. 14 * See the License for the specific language governing permissions 15 * and limitations under the License. 16 * ------------------------------------------------------------------- 17 */ 18 /**************************************************************************************** 19 Portions of this file are derived from the following 3GPP standard: 20 21 3GPP TS 26.173 22 ANSI-C code for the Adaptive Multi-Rate - Wideband (AMR-WB) speech codec 23 Available from http://www.3gpp.org 24 25 (C) 2007, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) 26 Permission to distribute, modify and use this file under the standard license 27 terms listed above has been obtained from the copyright holder. 28 ****************************************************************************************/ 29 /* 30 ------------------------------------------------------------------------------ 31 32 33 34 Filename: isp_az.cpp 35 36 Date: 05/08/2004 37 38 ------------------------------------------------------------------------------ 39 REVISION HISTORY 40 41 42 Description: 43 44 ------------------------------------------------------------------------------ 45 INPUT AND OUTPUT DEFINITIONS 46 47 int16 isp[], (i) Q15 : Immittance spectral pairs 48 int16 a[], (o) Q12 : predictor coefficients (order=M) 49 int16 m, (i) : order 50 int16 adaptive_scaling (i) 0 : adaptive scaling disabled 51 1 : adaptive scaling enabled 52 53 54 ------------------------------------------------------------------------------ 55 FUNCTION DESCRIPTION 56 57 Compute the LPC coefficients from isp (order=M) 58 ------------------------------------------------------------------------------ 59 REQUIREMENTS 60 61 62 ------------------------------------------------------------------------------ 63 REFERENCES 64 65 ------------------------------------------------------------------------------ 66 PSEUDO-CODE 67 68 ------------------------------------------------------------------------------ 69 */ 70 71 72 /*---------------------------------------------------------------------------- 73 ; INCLUDES 74 ----------------------------------------------------------------------------*/ 75 76 #include "pv_amr_wb_type_defs.h" 77 #include "pvamrwbdecoder_basic_op.h" 78 #include "pvamrwbdecoder_cnst.h" 79 #include "pvamrwbdecoder_acelp.h" 80 #include "pvamrwb_math_op.h" 81 82 /*---------------------------------------------------------------------------- 83 ; MACROS 84 ; Define module specific macros here 85 ----------------------------------------------------------------------------*/ 86 87 88 /*---------------------------------------------------------------------------- 89 ; DEFINES 90 ; Include all pre-processor statements here. Include conditional 91 ; compile variables also. 92 ----------------------------------------------------------------------------*/ 93 #define NC (M/2) 94 #define NC16k (M16k/2) 95 96 /*---------------------------------------------------------------------------- 97 ; LOCAL FUNCTION DEFINITIONS 98 ; Function Prototype declaration 99 ----------------------------------------------------------------------------*/ 100 101 102 #ifdef __cplusplus 103 extern "C" 104 { 105 #endif 106 107 void Get_isp_pol(int16 * isp, int32 * f, int16 n); 108 void Get_isp_pol_16kHz(int16 * isp, int32 * f, int16 n); 109 110 #ifdef __cplusplus 111 } 112 #endif 113 114 /*---------------------------------------------------------------------------- 115 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 116 ; Variable declaration - defined here and used outside this module 117 ----------------------------------------------------------------------------*/ 118 119 /*---------------------------------------------------------------------------- 120 ; EXTERNAL FUNCTION REFERENCES 121 ; Declare functions defined elsewhere and referenced in this module 122 ----------------------------------------------------------------------------*/ 123 124 /*---------------------------------------------------------------------------- 125 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 126 ; Declare variables used in this module but defined elsewhere 127 ----------------------------------------------------------------------------*/ 128 129 /*---------------------------------------------------------------------------- 130 ; FUNCTION CODE 131 ----------------------------------------------------------------------------*/ 132 133 void Isp_Az( 134 int16 isp[], /* (i) Q15 : Immittance spectral pairs */ 135 int16 a[], /* (o) Q12 : predictor coefficients (order=M) */ 136 int16 m, /* (i) : order */ 137 int16 adaptive_scaling /* (i) 0 : adaptive scaling disabled */ 138 /* 1 : adaptive scaling enabled */ 139 ) 140 { 141 int16 i, j; 142 int32 f1[NC16k + 1], f2[NC16k]; 143 int16 nc; 144 int32 t0; 145 int32 t1; 146 int16 q, q_sug; 147 int32 tmax; 148 149 nc = m >> 1; 150 151 152 if (nc > 8) 153 { 154 Get_isp_pol_16kHz(&isp[0], f1, nc); 155 for (i = 0; i <= nc; i++) 156 { 157 f1[i] = shl_int32(f1[i], 2); 158 } 159 Get_isp_pol_16kHz(&isp[1], f2, nc - 1); 160 for (i = 0; i <= nc - 1; i++) 161 { 162 f2[i] = shl_int32(f2[i], 2); 163 } 164 } 165 else 166 { 167 Get_isp_pol(&isp[0], f1, nc); 168 Get_isp_pol(&isp[1], f2, nc - 1); 169 } 170 171 /* 172 * Multiply F2(z) by (1 - z^-2) 173 */ 174 175 for (i = nc - 1; i > 1; i--) 176 { 177 f2[i] -= f2[i - 2]; /* f2[i] -= f2[i-2]; */ 178 } 179 180 /* 181 * Scale F1(z) by (1+isp[m-1]) and F2(z) by (1-isp[m-1]) 182 */ 183 184 for (i = 0; i < nc; i++) 185 { 186 /* f1[i] *= (1.0 + isp[M-1]); */ 187 188 /* f2[i] *= (1.0 - isp[M-1]); */ 189 t0 = f1[i]; 190 t1 = f2[i]; 191 t0 = fxp_mul32_by_16b(t0, isp[m - 1]) << 1; 192 t1 = fxp_mul32_by_16b(t1, isp[m - 1]) << 1; 193 f1[i] += t0; 194 f2[i] -= t1; 195 196 } 197 198 /* 199 * A(z) = (F1(z)+F2(z))/2 200 * F1(z) is symmetric and F2(z) is antisymmetric 201 */ 202 203 /* a[0] = 1.0; */ 204 a[0] = 4096; 205 tmax = 1; 206 j = m - 1; 207 for (i = 1; i < nc; i++) 208 { 209 /* a[i] = 0.5*(f1[i] + f2[i]); */ 210 211 t0 = add_int32(f1[i], f2[i]); /* f1[i] + f2[i] */ 212 /* compute t1 = abs(t0) */ 213 t1 = t0 - (t0 < 0); 214 t1 = t1 ^(t1 >> 31); /* t1 = t1 ^sign(t1) */ 215 216 tmax |= t1; 217 /* from Q23 to Q12 and * 0.5 */ 218 a[i] = (int16)((t0 >> 12) + ((t0 >> 11) & 1)); 219 220 221 /* a[j] = 0.5*(f1[i] - f2[i]); */ 222 223 t0 = sub_int32(f1[i], f2[i]); /* f1[i] - f2[i] */ 224 /* compute t1 = abs(t0) */ 225 t1 = t0 - (t0 < 0); 226 t1 = t1 ^(t1 >> 31); /* t1 = t1 ^sign(t1) */ 227 228 tmax |= t1; 229 230 /* from Q23 to Q12 and * 0.5 */ 231 a[j--] = (int16)((t0 >> 12) + ((t0 >> 11) & 1)); 232 233 } 234 235 /* rescale data if overflow has occured and reprocess the loop */ 236 237 238 if (adaptive_scaling == 1) 239 { 240 q = 4 - normalize_amr_wb(tmax); /* adaptive scaling enabled */ 241 } 242 else 243 { 244 q = 0; /* adaptive scaling disabled */ 245 } 246 247 248 if (q > 0) 249 { 250 q_sug = 12 + q; 251 for (i = 1, j = m - 1; i < nc; i++, j--) 252 { 253 /* a[i] = 0.5*(f1[i] + f2[i]); */ 254 255 t0 = add_int32(f1[i], f2[i]); /* f1[i] + f2[i] */ 256 /* from Q23 to Q12 and * 0.5 */ 257 a[i] = (int16)((t0 >> q_sug) + ((t0 >> (q_sug - 1)) & 1)); 258 259 260 /* a[j] = 0.5*(f1[i] - f2[i]); */ 261 262 t0 = sub_int32(f1[i], f2[i]); /* f1[i] - f2[i] */ 263 /* from Q23 to Q12 and * 0.5 */ 264 a[j] = (int16)((t0 >> q_sug) + ((t0 >> (q_sug - 1)) & 1)); 265 266 } 267 a[0] >>= q; 268 } 269 else 270 { 271 q_sug = 12; 272 q = 0; 273 } 274 275 /* a[NC] = 0.5*f1[NC]*(1.0 + isp[M-1]); */ 276 277 278 t0 = (int32)(((int64)f1[nc] * isp[m - 1]) >> 16) << 1; 279 280 281 t0 = add_int32(f1[nc], t0); 282 283 /* from Q23 to Q12 and * 0.5 */ 284 a[nc] = (int16)((t0 >> q_sug) + ((t0 >> (q_sug - 1)) & 1)); 285 a[m] = shr_rnd(isp[m - 1], (3 + q)); /* from Q15 to Q12 */ 286 287 /* a[m] = isp[m-1]; */ 288 289 290 return; 291 } 292 293 294 295 /* 296 Get_isp_pol 297 ------------------------------------------------------------------------------ 298 INPUT AND OUTPUT DEFINITIONS 299 300 isp[] : isp vector (cosine domaine) in Q15 301 f[] : the coefficients of F1 or F2 in Q23 302 n : == NC for F1(z); == NC-1 for F2(z) 303 304 305 ------------------------------------------------------------------------------ 306 FUNCTION DESCRIPTION 307 308 Find the polynomial F1(z) or F2(z) from the ISPs. 309 This is performed by expanding the product polynomials: 310 311 F1(z) = product ( 1 - 2 isp_i z^-1 + z^-2 ) 312 i=0,2,4,6,8 313 F2(z) = product ( 1 - 2 isp_i z^-1 + z^-2 ) 314 i=1,3,5,7 315 316 where isp_i are the ISPs in the cosine domain. 317 ------------------------------------------------------------------------------ 318 REQUIREMENTS 319 320 321 ------------------------------------------------------------------------------ 322 REFERENCES 323 324 ------------------------------------------------------------------------------ 325 PSEUDO-CODE 326 327 ----------------------------------------------------------------------------*/ 328 329 /*---------------------------------------------------------------------------- 330 ; FUNCTION CODE 331 ----------------------------------------------------------------------------*/ 332 333 334 void Get_isp_pol(int16 * isp, int32 * f, int16 n) 335 { 336 int16 i, j; 337 int32 t0; 338 339 340 /* All computation in Q23 */ 341 342 f[0] = 0x00800000; /* f[0] = 1.0; in Q23 */ 343 f[1] = -isp[0] << 9; /* f[1] = -2.0*isp[0] in Q23 */ 344 345 f += 2; /* Advance f pointer */ 346 isp += 2; /* Advance isp pointer */ 347 348 for (i = 2; i <= n; i++) 349 { 350 *f = f[-2]; 351 352 for (j = 1; j < i; j++) 353 { 354 355 t0 = fxp_mul32_by_16b(f[-1], *isp); 356 t0 = shl_int32(t0, 2); 357 358 *f -= t0; /* *f -= t0 */ 359 *(f) += f[-2]; /* *f += f[-2] */ 360 f--; 361 362 363 } 364 *f -= *isp << 9; 365 366 f += i; /* Advance f pointer */ 367 isp += 2; /* Advance isp pointer */ 368 } 369 } 370 371 void Get_isp_pol_16kHz(int16 * isp, int32 * f, int16 n) 372 { 373 int16 i, j; 374 int32 t0; 375 376 /* All computation in Q23 */ 377 378 f[0] = 0x00200000; /* f[0] = 0.25; in Q23 */ 379 380 f[1] = -isp[0] << 7; /* f[1] = -0.5*isp[0] in Q23 */ 381 382 f += 2; /* Advance f pointer */ 383 isp += 2; /* Advance isp pointer */ 384 385 for (i = 2; i <= n; i++) 386 { 387 *f = f[-2]; 388 389 for (j = 1; j < i; j++, f--) 390 { 391 t0 = fxp_mul32_by_16b(f[-1], *isp); 392 t0 = shl_int32(t0, 2); 393 394 *f -= t0; /* *f -= t0 */ 395 *f += f[-2]; /* *f += f[-2] */ 396 } 397 *f -= *isp << 7; 398 f += i; /* Advance f pointer */ 399 isp += 2; /* Advance isp pointer */ 400 } 401 return; 402 } 403 404
