apps/codecs/libfaad/sbr_hfgen.c

   1 /*
   2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
   3 ** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
   4 **
   5 ** This program is free software; you can redistribute it and/or modify
   6 ** it under the terms of the GNU General Public License as published by
   7 ** the Free Software Foundation; either version 2 of the License, or
   8 ** (at your option) any later version.
   9 **
  10 ** This program is distributed in the hope that it will be useful,
  11 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 ** GNU General Public License for more details.
  14 **
  15 ** You should have received a copy of the GNU General Public License
  16 ** along with this program; if not, write to the Free Software
  17 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18 **
  19 ** Any non-GPL usage of this software or parts of this software is strictly
  20 ** forbidden.
  21 **
  22 ** Commercial non-GPL licensing of this software is possible.
  23 ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
  24 **
  25 ** $Id$
  26 **/
  27
  28 /* High Frequency generation */
  29
  30 #include "common.h"
  31 #include "structs.h"
  32
  33 #ifdef SBR_DEC
  34
  35 #include "sbr_syntax.h"
  36 #include "sbr_hfgen.h"
  37 #include "sbr_fbt.h"
  38
  39
  40 /* static function declarations */
  41 #ifdef SBR_LOW_POWER
  42 static void calc_prediction_coef_lp(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
  43                                     complex_t *alpha_0, complex_t *alpha_1, real_t *rxx);
  44 static void calc_aliasing_degree(sbr_info *sbr, real_t *rxx, real_t *deg);
  45 #else
  46 static void calc_prediction_coef(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
  47                                  complex_t *alpha_0, complex_t *alpha_1, uint8_t k);
  48 #endif
  49 static void calc_chirp_factors(sbr_info *sbr, uint8_t ch);
  50 static void patch_construction(sbr_info *sbr);
  51
  52
  53 void hf_generation(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
  54                    qmf_t Xhigh[MAX_NTSRHFG][64]
  55 #ifdef SBR_LOW_POWER
  56                    ,real_t *deg
  57 #endif
  58                    ,uint8_t ch)
  59 {
  60     uint8_t l, i, x;
  61     ALIGN complex_t alpha_0[64], alpha_1[64];
  62 #ifdef SBR_LOW_POWER
  63     ALIGN real_t rxx[64];
  64 #endif
  65
  66     uint8_t offset = sbr->tHFAdj;
  67     uint8_t first = sbr->t_E[ch][0];
  68     uint8_t last = sbr->t_E[ch][sbr->L_E[ch]];
  69
  70     calc_chirp_factors(sbr, ch);
  71
  72 #ifdef SBR_LOW_POWER
  73     memset(deg, 0, 64*sizeof(real_t));
  74 #endif
  75
  76     if ((ch == 0) && (sbr->Reset))
  77         patch_construction(sbr);
  78
  79     /* calculate the prediction coefficients */
  80 #ifdef SBR_LOW_POWER
  81     calc_prediction_coef_lp(sbr, Xlow, alpha_0, alpha_1, rxx);
  82     calc_aliasing_degree(sbr, rxx, deg);
  83 #endif
  84
  85     /* actual HF generation */
  86     for (i = 0; i < sbr->noPatches; i++)
  87     {
  88         for (x = 0; x < sbr->patchNoSubbands[i]; x++)
  89         {
  90             real_t a0_r, a0_i, a1_r, a1_i;
  91             real_t bw, bw2;
  92             uint8_t q, p, k, g;
  93
  94             /* find the low and high band for patching */
  95             k = sbr->kx + x;
  96             for (q = 0; q < i; q++)
  97             {
  98                 k += sbr->patchNoSubbands[q];
  99             }
 100             p = sbr->patchStartSubband[i] + x;
 101
 102 #ifdef SBR_LOW_POWER
 103             if (x != 0 /*x < sbr->patchNoSubbands[i]-1*/)
 104                 deg[k] = deg[p];
 105             else
 106                 deg[k] = 0;
 107 #endif
 108
 109             g = sbr->table_map_k_to_g[k];
 110
 111             bw = sbr->bwArray[ch][g];
 112             bw2 = MUL_C(bw, bw);
 113
 114             /* do the patching */
 115             /* with or without filtering */
 116             if (bw2 > 0)
 117             {
 118                 real_t temp1_r, temp2_r, temp3_r;
 119 #ifndef SBR_LOW_POWER
 120                 real_t temp1_i, temp2_i, temp3_i;
 121                 calc_prediction_coef(sbr, Xlow, alpha_0, alpha_1, p);
 122 #endif
 123
 124                 a0_r = MUL_C(RE(alpha_0[p]), bw);
 125                 a1_r = MUL_C(RE(alpha_1[p]), bw2);
 126 #ifndef SBR_LOW_POWER
 127                 a0_i = MUL_C(IM(alpha_0[p]), bw);
 128                 a1_i = MUL_C(IM(alpha_1[p]), bw2);
 129 #endif
 130
 131                 temp2_r = QMF_RE(Xlow[first - 2 + offset][p]);
 132                 temp3_r = QMF_RE(Xlow[first - 1 + offset][p]);
 133 #ifndef SBR_LOW_POWER
 134                 temp2_i = QMF_IM(Xlow[first - 2 + offset][p]);
 135                 temp3_i = QMF_IM(Xlow[first - 1 + offset][p]);
 136 #endif
 137                 for (l = first; l < last; l++)
 138                 {
 139                     temp1_r = temp2_r;
 140                     temp2_r = temp3_r;
 141                     temp3_r = QMF_RE(Xlow[l + offset][p]);
 142 #ifndef SBR_LOW_POWER
 143                     temp1_i = temp2_i;
 144                     temp2_i = temp3_i;
 145                     temp3_i = QMF_IM(Xlow[l + offset][p]);
 146 #endif
 147
 148 #ifdef SBR_LOW_POWER
 149                     QMF_RE(Xhigh[l + offset][k]) =
 150                         temp3_r
 151                       +(MUL_R(a0_r, temp2_r) +
 152                         MUL_R(a1_r, temp1_r));
 153 #else
 154                     QMF_RE(Xhigh[l + offset][k]) =
 155                         temp3_r
 156                       +(MUL_R(a0_r, temp2_r) -
 157                         MUL_R(a0_i, temp2_i) +
 158                         MUL_R(a1_r, temp1_r) -
 159                         MUL_R(a1_i, temp1_i));
 160                     QMF_IM(Xhigh[l + offset][k]) =
 161                         temp3_i
 162                       +(MUL_R(a0_i, temp2_r) +
 163                         MUL_R(a0_r, temp2_i) +
 164                         MUL_R(a1_i, temp1_r) +
 165                         MUL_R(a1_r, temp1_i));
 166 #endif
 167                 }
 168             } else {
 169                 for (l = first; l < last; l++)
 170                 {
 171                     QMF_RE(Xhigh[l + offset][k]) = QMF_RE(Xlow[l + offset][p]);
 172 #ifndef SBR_LOW_POWER
 173                     QMF_IM(Xhigh[l + offset][k]) = QMF_IM(Xlow[l + offset][p]);
 174 #endif
 175                 }
 176             }
 177         }
 178     }
 179
 180     if (sbr->Reset)
 181     {
 182         limiter_frequency_table(sbr);
 183     }
 184 }
 185
 186 typedef struct
 187 {
 188     complex_t r01;
 189     complex_t r02;
 190     complex_t r11;
 191     complex_t r12;
 192     complex_t r22;
 193     real_t det;
 194 } acorr_coef;
 195
 196 #ifdef SBR_LOW_POWER
 197 static void auto_correlation(sbr_info *sbr, acorr_coef *ac,
 198                              qmf_t buffer[MAX_NTSRHFG][64],
 199                              uint8_t bd, uint8_t len)
 200 {
 201     real_t r01 = 0, r02 = 0, r11 = 0;
 202     int8_t j;
 203     uint8_t offset = sbr->tHFAdj;
 204 #ifdef FIXED_POINT
 205     const real_t rel = FRAC_CONST(0.999999); // 1 / (1 + 1e-6f);
 206     uint32_t maxi = 0;
 207     uint32_t pow2, exp;
 208 #else
 209     const real_t rel = 1 / (1 + 1e-6f);
 210 #endif
 211
 212
 213 #ifdef FIXED_POINT
 214     mask = 0;
 215
 216     for (j = (offset-2); j < (len + offset); j++)
 217     {
 218         real_t x;
 219         x = QMF_RE(buffer[j][bd])>>REAL_BITS;
 220         mask |= x ^ (x >> 31);
 221     }
 222
 223     exp = wl_min_lzc(mask);
 224
 225     for (j = offset; j < len + offset; j++)
 226     {
 227         real_t buf_j = ((QMF_RE(buffer[j][bd])+(1<<(exp-1)))>>exp);
 228         real_t buf_j_1 = ((QMF_RE(buffer[j-1][bd])+(1<<(exp-1)))>>exp);
 229         real_t buf_j_2 = ((QMF_RE(buffer[j-2][bd])+(1<<(exp-1)))>>exp);
 230
 231         /* normalisation with rounding */
 232         r01 += MUL_R(buf_j, buf_j_1);
 233         r02 += MUL_R(buf_j, buf_j_2);
 234         r11 += MUL_R(buf_j_1, buf_j_1);
 235     }
 236     RE(ac->r12) = r01 -
 237         MUL_R(((QMF_RE(buffer[len+offset-1][bd])+(1<<(exp-1)))>>exp), ((QMF_RE(buffer[len+offset-2][bd])+(1<<(exp-1)))>>exp)) +
 238         MUL_R(((QMF_RE(buffer[offset-1][bd])+(1<<(exp-1)))>>exp), ((QMF_RE(buffer[offset-2][bd])+(1<<(exp-1)))>>exp));
 239     RE(ac->r22) = r11 -
 240         MUL_R(((QMF_RE(buffer[len+offset-2][bd])+(1<<(exp-1)))>>exp), ((QMF_RE(buffer[len+offset-2][bd])+(1<<(exp-1)))>>exp)) +
 241         MUL_R(((QMF_RE(buffer[offset-2][bd])+(1<<(exp-1)))>>exp), ((QMF_RE(buffer[offset-2][bd])+(1<<(exp-1)))>>exp));
 242 #else
 243     for (j = offset; j < len + offset; j++)
 244     {
 245         r01 += QMF_RE(buffer[j][bd]) * QMF_RE(buffer[j-1][bd]);
 246         r02 += QMF_RE(buffer[j][bd]) * QMF_RE(buffer[j-2][bd]);
 247         r11 += QMF_RE(buffer[j-1][bd]) * QMF_RE(buffer[j-1][bd]);
 248     }
 249     RE(ac->r12) = r01 -
 250         QMF_RE(buffer[len+offset-1][bd]) * QMF_RE(buffer[len+offset-2][bd]) +
 251         QMF_RE(buffer[offset-1][bd]) * QMF_RE(buffer[offset-2][bd]);
 252     RE(ac->r22) = r11 -
 253         QMF_RE(buffer[len+offset-2][bd]) * QMF_RE(buffer[len+offset-2][bd]) +
 254         QMF_RE(buffer[offset-2][bd]) * QMF_RE(buffer[offset-2][bd]);
 255 #endif
 256     RE(ac->r01) = r01;
 257     RE(ac->r02) = r02;
 258     RE(ac->r11) = r11;
 259
 260     ac->det = MUL_R(RE(ac->r11), RE(ac->r22)) - MUL_F(MUL_R(RE(ac->r12), RE(ac->r12)), rel);
 261 }
 262 #else
 263 static void auto_correlation(sbr_info *sbr, acorr_coef *ac, qmf_t buffer[MAX_NTSRHFG][64],
 264                              uint8_t bd, uint8_t len)
 265 {
 266     real_t r01r = 0, r01i = 0, r02r = 0, r02i = 0, r11r = 0;
 267     real_t temp1_r, temp1_i, temp2_r, temp2_i, temp3_r, temp3_i, temp4_r, temp4_i, temp5_r, temp5_i;
 268 #ifdef FIXED_POINT
 269     const real_t rel = FRAC_CONST(0.999999); // 1 / (1 + 1e-6f);
 270     uint32_t mask, exp;
 271     real_t pow2_to_exp;
 272 #else
 273     const real_t rel = 1 / (1 + 1e-6f);
 274 #endif
 275     int8_t j;
 276     uint8_t offset = sbr->tHFAdj;
 277
 278 #ifdef FIXED_POINT
 279     mask = 0;
 280
 281     for (j = (offset-2); j < (len + offset); j++)
 282     {
 283         real_t x;
 284         x = QMF_RE(buffer[j][bd])>>REAL_BITS;
 285         mask |= x ^ (x >> 31);
 286         x = QMF_IM(buffer[j][bd])>>REAL_BITS;
 287         mask |= x ^ (x >> 31);
 288     }
 289
 290     exp = wl_min_lzc(mask);
 291
 292     pow2_to_exp = 1<<(exp-1);
 293
 294     temp2_r = (QMF_RE(buffer[offset-2][bd]) + pow2_to_exp) >> exp;
 295     temp2_i = (QMF_IM(buffer[offset-2][bd]) + pow2_to_exp) >> exp;
 296     temp3_r = (QMF_RE(buffer[offset-1][bd]) + pow2_to_exp) >> exp;
 297     temp3_i = (QMF_IM(buffer[offset-1][bd]) + pow2_to_exp) >> exp;
 298     // Save these because they are needed after loop
 299     temp4_r = temp2_r;
 300     temp4_i = temp2_i;
 301     temp5_r = temp3_r;
 302     temp5_i = temp3_i;
 303
 304     for (j = offset; j < len + offset; j++)
 305     {
 306         temp1_r = temp2_r; // temp1_r = (QMF_RE(buffer[offset-2][bd] + (1<<(exp-1))) >> exp;
 307         temp1_i = temp2_i; // temp1_i = (QMF_IM(buffer[offset-2][bd] + (1<<(exp-1))) >> exp;
 308         temp2_r = temp3_r; // temp2_r = (QMF_RE(buffer[offset-1][bd] + (1<<(exp-1))) >> exp;
 309         temp2_i = temp3_i; // temp2_i = (QMF_IM(buffer[offset-1][bd] + (1<<(exp-1))) >> exp;
 310         temp3_r = (QMF_RE(buffer[j][bd]) + pow2_to_exp) >> exp;
 311         temp3_i = (QMF_IM(buffer[j][bd]) + pow2_to_exp) >> exp;
 312         r01r += MUL_R(temp3_r, temp2_r) + MUL_R(temp3_i, temp2_i);
 313         r01i += MUL_R(temp3_i, temp2_r) - MUL_R(temp3_r, temp2_i);
 314         r02r += MUL_R(temp3_r, temp1_r) + MUL_R(temp3_i, temp1_i);
 315         r02i += MUL_R(temp3_i, temp1_r) - MUL_R(temp3_r, temp1_i);
 316         r11r += MUL_R(temp2_r, temp2_r) + MUL_R(temp2_i, temp2_i);
 317     }
 318
 319     // These are actual values in temporary variable at this point
 320     // temp1_r = (QMF_RE(buffer[len+offset-1-2][bd] + (1<<(exp-1))) >> exp;
 321     // temp1_i = (QMF_IM(buffer[len+offset-1-2][bd] + (1<<(exp-1))) >> exp;
 322     // temp2_r = (QMF_RE(buffer[len+offset-1-1][bd] + (1<<(exp-1))) >> exp;
 323     // temp2_i = (QMF_IM(buffer[len+offset-1-1][bd] + (1<<(exp-1))) >> exp;
 324     // temp3_r = (QMF_RE(buffer[len+offset-1][bd]) + (1<<(exp-1))) >> exp;
 325     // temp3_i = (QMF_IM(buffer[len+offset-1][bd]) + (1<<(exp-1))) >> exp;
 326     // temp4_r = (QMF_RE(buffer[offset-2][bd]) + (1<<(exp-1))) >> exp;
 327     // temp4_i = (QMF_IM(buffer[offset-2][bd]) + (1<<(exp-1))) >> exp;
 328     // temp5_r = (QMF_RE(buffer[offset-1][bd]) + (1<<(exp-1))) >> exp;
 329     // temp5_i = (QMF_IM(buffer[offset-1][bd]) + (1<<(exp-1))) >> exp;
 330
 331     RE(ac->r12) = r01r -
 332         (MUL_R(temp3_r, temp2_r) + MUL_R(temp3_i, temp2_i)) +
 333         (MUL_R(temp5_r, temp4_r) + MUL_R(temp5_i, temp4_i));
 334     IM(ac->r12) = r01i -
 335         (MUL_R(temp3_i, temp2_r) - MUL_R(temp3_r, temp2_i)) +
 336         (MUL_R(temp5_i, temp4_r) - MUL_R(temp5_r, temp4_i));
 337     RE(ac->r22) = r11r -
 338         (MUL_R(temp2_r, temp2_r) + MUL_R(temp2_i, temp2_i)) +
 339         (MUL_R(temp4_r, temp4_r) + MUL_R(temp4_i, temp4_i));
 340
 341 #else
 342
 343     temp2_r = QMF_RE(buffer[offset-2][bd]);
 344     temp2_i = QMF_IM(buffer[offset-2][bd]);
 345     temp3_r = QMF_RE(buffer[offset-1][bd]);
 346     temp3_i = QMF_IM(buffer[offset-1][bd]);
 347     // Save these because they are needed after loop
 348     temp4_r = temp2_r;
 349     temp4_i = temp2_i;
 350     temp5_r = temp3_r;
 351     temp5_i = temp3_i;
 352
 353     for (j = offset; j < len + offset; j++)
 354     {
 355         temp1_r = temp2_r; // temp1_r = QMF_RE(buffer[j-2][bd];
 356         temp1_i = temp2_i; // temp1_i = QMF_IM(buffer[j-2][bd];
 357         temp2_r = temp3_r; // temp2_r = QMF_RE(buffer[j-1][bd];
 358         temp2_i = temp3_i; // temp2_i = QMF_IM(buffer[j-1][bd];
 359         temp3_r = QMF_RE(buffer[j][bd]);
 360         temp3_i = QMF_IM(buffer[j][bd]);
 361         r01r += temp3_r * temp2_r + temp3_i * temp2_i;
 362         r01i += temp3_i * temp2_r - temp3_r * temp2_i;
 363         r02r += temp3_r * temp1_r + temp3_i * temp1_i;
 364         r02i += temp3_i * temp1_r - temp3_r * temp1_i;
 365         r11r += temp2_r * temp2_r + temp2_i * temp2_i;
 366     }
 367
 368     // These are actual values in temporary variable at this point
 369     // temp1_r = QMF_RE(buffer[len+offset-1-2][bd];
 370     // temp1_i = QMF_IM(buffer[len+offset-1-2][bd];
 371     // temp2_r = QMF_RE(buffer[len+offset-1-1][bd];
 372     // temp2_i = QMF_IM(buffer[len+offset-1-1][bd];
 373     // temp3_r = QMF_RE(buffer[len+offset-1][bd]);
 374     // temp3_i = QMF_IM(buffer[len+offset-1][bd]);
 375     // temp4_r = QMF_RE(buffer[offset-2][bd]);
 376     // temp4_i = QMF_IM(buffer[offset-2][bd]);
 377     // temp5_r = QMF_RE(buffer[offset-1][bd]);
 378     // temp5_i = QMF_IM(buffer[offset-1][bd]);
 379
 380     RE(ac->r12) = r01r -
 381         (temp3_r * temp2_r + temp3_i * temp2_i) +
 382         (temp5_r * temp4_r + temp5_i * temp4_i);
 383     IM(ac->r12) = r01i -
 384         (temp3_i * temp2_r - temp3_r * temp2_i) +
 385         (temp5_i * temp4_r - temp5_r * temp4_i);
 386     RE(ac->r22) = r11r -
 387         (temp2_r * temp2_r + temp2_i * temp2_i) +
 388         (temp4_r * temp4_r + temp4_i * temp4_i);
 389
 390 #endif
 391
 392     RE(ac->r01) = r01r;
 393     IM(ac->r01) = r01i;
 394     RE(ac->r02) = r02r;
 395     IM(ac->r02) = r02i;
 396     RE(ac->r11) = r11r;
 397
 398     ac->det = MUL_R(RE(ac->r11), RE(ac->r22)) - MUL_F(rel, (MUL_R(RE(ac->r12), RE(ac->r12)) + MUL_R(IM(ac->r12), IM(ac->r12))));
 399 }
 400 #endif
 401
 402 /* calculate linear prediction coefficients using the covariance method */
 403 #ifndef SBR_LOW_POWER
 404 static void calc_prediction_coef(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
 405                                  complex_t *alpha_0, complex_t *alpha_1, uint8_t k)
 406 {
 407     real_t tmp;
 408     acorr_coef ac;
 409
 410     auto_correlation(sbr, &ac, Xlow, k, sbr->numTimeSlotsRate + 6);
 411
 412     if (ac.det == 0)
 413     {
 414         RE(alpha_1[k]) = 0;
 415         IM(alpha_1[k]) = 0;
 416     } else {
 417 #ifdef FIXED_POINT
 418         tmp = (MUL_R(RE(ac.r01), RE(ac.r12)) - MUL_R(IM(ac.r01), IM(ac.r12)) - MUL_R(RE(ac.r02), RE(ac.r11)));
 419         RE(alpha_1[k]) = DIV_R(tmp, ac.det);
 420         tmp = (MUL_R(IM(ac.r01), RE(ac.r12)) + MUL_R(RE(ac.r01), IM(ac.r12)) - MUL_R(IM(ac.r02), RE(ac.r11)));
 421         IM(alpha_1[k]) = DIV_R(tmp, ac.det);
 422 #else
 423         tmp = REAL_CONST(1.0) / ac.det;
 424         RE(alpha_1[k]) = (MUL_R(RE(ac.r01), RE(ac.r12)) - MUL_R(IM(ac.r01), IM(ac.r12)) - MUL_R(RE(ac.r02), RE(ac.r11))) * tmp;
 425         IM(alpha_1[k]) = (MUL_R(IM(ac.r01), RE(ac.r12)) + MUL_R(RE(ac.r01), IM(ac.r12)) - MUL_R(IM(ac.r02), RE(ac.r11))) * tmp;
 426 #endif
 427     }
 428
 429     if (RE(ac.r11) == 0)
 430     {
 431         RE(alpha_0[k]) = 0;
 432         IM(alpha_0[k]) = 0;
 433     } else {
 434 #ifdef FIXED_POINT
 435         tmp = -(RE(ac.r01) + MUL_R(RE(alpha_1[k]), RE(ac.r12)) + MUL_R(IM(alpha_1[k]), IM(ac.r12)));
 436         RE(alpha_0[k]) = DIV_R(tmp, RE(ac.r11));
 437         tmp = -(IM(ac.r01) + MUL_R(IM(alpha_1[k]), RE(ac.r12)) - MUL_R(RE(alpha_1[k]), IM(ac.r12)));
 438         IM(alpha_0[k]) = DIV_R(tmp, RE(ac.r11));
 439 #else
 440         tmp = 1.0f / RE(ac.r11);
 441         RE(alpha_0[k]) = -(RE(ac.r01) + MUL_R(RE(alpha_1[k]), RE(ac.r12)) + MUL_R(IM(alpha_1[k]), IM(ac.r12))) * tmp;
 442         IM(alpha_0[k]) = -(IM(ac.r01) + MUL_R(IM(alpha_1[k]), RE(ac.r12)) - MUL_R(RE(alpha_1[k]), IM(ac.r12))) * tmp;
 443 #endif
 444     }
 445
 446     if ((MUL_R(RE(alpha_0[k]),RE(alpha_0[k])) + MUL_R(IM(alpha_0[k]),IM(alpha_0[k])) >= REAL_CONST(16)) ||
 447         (MUL_R(RE(alpha_1[k]),RE(alpha_1[k])) + MUL_R(IM(alpha_1[k]),IM(alpha_1[k])) >= REAL_CONST(16)))
 448     {
 449         RE(alpha_0[k]) = 0;
 450         IM(alpha_0[k]) = 0;
 451         RE(alpha_1[k]) = 0;
 452         IM(alpha_1[k]) = 0;
 453     }
 454 }
 455 #else
 456 static void calc_prediction_coef_lp(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
 457                                     complex_t *alpha_0, complex_t *alpha_1, real_t *rxx)
 458 {
 459     uint8_t k;
 460     real_t tmp;
 461     acorr_coef ac;
 462
 463     for (k = 1; k < sbr->f_master[0]; k++)
 464     {
 465         auto_correlation(sbr, &ac, Xlow, k, sbr->numTimeSlotsRate + 6);
 466
 467         if (ac.det == 0)
 468         {
 469             RE(alpha_0[k]) = 0;
 470             RE(alpha_1[k]) = 0;
 471         } else {
 472             tmp = MUL_R(RE(ac.r01), RE(ac.r22)) - MUL_R(RE(ac.r12), RE(ac.r02));
 473             RE(alpha_0[k]) = DIV_R(tmp, (-ac.det));
 474
 475             tmp = MUL_R(RE(ac.r01), RE(ac.r12)) - MUL_R(RE(ac.r02), RE(ac.r11));
 476             RE(alpha_1[k]) = DIV_R(tmp, ac.det);
 477         }
 478
 479         if ((RE(alpha_0[k]) >= REAL_CONST(4)) || (RE(alpha_1[k]) >= REAL_CONST(4)))
 480         {
 481             RE(alpha_0[k]) = REAL_CONST(0);
 482             RE(alpha_1[k]) = REAL_CONST(0);
 483         }
 484
 485         /* reflection coefficient */
 486         if (RE(ac.r11) == 0)
 487         {
 488             rxx[k] = COEF_CONST(0.0);
 489         } else {
 490             rxx[k] = DIV_C(RE(ac.r01), RE(ac.r11));
 491             rxx[k] = -rxx[k];
 492             if (rxx[k] > COEF_CONST(1.0)) rxx[k] = COEF_CONST(1.0);
 493             if (rxx[k] < COEF_CONST(-1.0)) rxx[k] = COEF_CONST(-1.0);
 494         }
 495     }
 496 }
 497
 498 static void calc_aliasing_degree(sbr_info *sbr, real_t *rxx, real_t *deg)
 499 {
 500     uint8_t k;
 501
 502     rxx[0] = COEF_CONST(0.0);
 503     deg[1] = COEF_CONST(0.0);
 504
 505     for (k = 2; k < sbr->k0; k++)
 506     {
 507         deg[k] = 0.0;
 508
 509         if ((k % 2 == 0) && (rxx[k] < COEF_CONST(0.0)))
 510         {
 511             if (rxx[k-1] < 0.0)
 512             {
 513                 deg[k] = COEF_CONST(1.0);
 514
 515                 if (rxx[k-2] > COEF_CONST(0.0))
 516                 {
 517                     deg[k-1] = COEF_CONST(1.0) - MUL_C(rxx[k-1], rxx[k-1]);
 518                 }
 519             } else if (rxx[k-2] > COEF_CONST(0.0)) {
 520                 deg[k] = COEF_CONST(1.0) - MUL_C(rxx[k-1], rxx[k-1]);
 521             }
 522         }
 523
 524         if ((k % 2 == 1) && (rxx[k] > COEF_CONST(0.0)))
 525         {
 526             if (rxx[k-1] > COEF_CONST(0.0))
 527             {
 528                 deg[k] = COEF_CONST(1.0);
 529
 530                 if (rxx[k-2] < COEF_CONST(0.0))
 531                 {
 532                     deg[k-1] = COEF_CONST(1.0) - MUL_C(rxx[k-1], rxx[k-1]);
 533                 }
 534             } else if (rxx[k-2] < COEF_CONST(0.0)) {
 535                 deg[k] = COEF_CONST(1.0) - MUL_C(rxx[k-1], rxx[k-1]);
 536             }
 537         }
 538     }
 539 }
 540 #endif
 541
 542 /* FIXED POINT: bwArray = COEF */
 543 static real_t mapNewBw(uint8_t invf_mode, uint8_t invf_mode_prev)
 544 {
 545     switch (invf_mode)
 546     {
 547     case 1: /* LOW */
 548         if (invf_mode_prev == 0) /* NONE */
 549             return COEF_CONST(0.6);
 550         else
 551             return COEF_CONST(0.75);
 552
 553     case 2: /* MID */
 554         return COEF_CONST(0.9);
 555
 556     case 3: /* HIGH */
 557         return COEF_CONST(0.98);
 558
 559     default: /* NONE */
 560         if (invf_mode_prev == 1) /* LOW */
 561             return COEF_CONST(0.6);
 562         else
 563             return COEF_CONST(0.0);
 564     }
 565 }
 566
 567 /* FIXED POINT: bwArray = COEF */
 568 static void calc_chirp_factors(sbr_info *sbr, uint8_t ch)
 569 {
 570     uint8_t i;
 571
 572     for (i = 0; i < sbr->N_Q; i++)
 573     {
 574         sbr->bwArray[ch][i] = mapNewBw(sbr->bs_invf_mode[ch][i], sbr->bs_invf_mode_prev[ch][i]);
 575
 576         if (sbr->bwArray[ch][i] < sbr->bwArray_prev[ch][i])
 577             sbr->bwArray[ch][i] = MUL_F(sbr->bwArray[ch][i], FRAC_CONST(0.75)) + MUL_F(sbr->bwArray_prev[ch][i], FRAC_CONST(0.25));
 578         else
 579             sbr->bwArray[ch][i] = MUL_F(sbr->bwArray[ch][i], FRAC_CONST(0.90625)) + MUL_F(sbr->bwArray_prev[ch][i], FRAC_CONST(0.09375));
 580
 581         if (sbr->bwArray[ch][i] < COEF_CONST(0.015625))
 582             sbr->bwArray[ch][i] = COEF_CONST(0.0);
 583
 584         if (sbr->bwArray[ch][i] >= COEF_CONST(0.99609375))
 585             sbr->bwArray[ch][i] = COEF_CONST(0.99609375);
 586
 587         sbr->bwArray_prev[ch][i] = sbr->bwArray[ch][i];
 588         sbr->bs_invf_mode_prev[ch][i] = sbr->bs_invf_mode[ch][i];
 589     }
 590 }
 591
 592 static void patch_construction(sbr_info *sbr)
 593 {
 594     uint8_t i, k;
 595     uint8_t odd, sb;
 596     uint8_t msb = sbr->k0;
 597     uint8_t usb = sbr->kx;
 598     uint8_t goalSbTab[] = { 21, 23, 32, 43, 46, 64, 85, 93, 128, 0, 0, 0 };
 599     /* (uint8_t)(2.048e6/sbr->sample_rate + 0.5); */
 600     uint8_t goalSb = goalSbTab[get_sr_index(sbr->sample_rate)];
 601
 602     sbr->noPatches = 0;
 603
 604     if (goalSb < (sbr->kx + sbr->M))
 605     {
 606         for (i = 0, k = 0; sbr->f_master[i] < goalSb; i++)
 607             k = i+1;
 608     } else {
 609         k = sbr->N_master;
 610     }
 611
 612     if (sbr->N_master == 0)
 613     {
 614         sbr->noPatches = 0;
 615         sbr->patchNoSubbands[0] = 0;
 616         sbr->patchStartSubband[0] = 0;
 617
 618         return;
 619     }
 620
 621     do
 622     {
 623         int8_t j = k + 1;
 624
 625         do
 626         {
 627             j--;
 628             sb = sbr->f_master[j];
 629             odd = (sb - 2 + sbr->k0) % 2;
 630
 631         } while (sb > (sbr->k0 - 1 + msb - odd));
 632
 633         sbr->patchNoSubbands[sbr->noPatches] = max(sb - usb, 0);
 634         sbr->patchStartSubband[sbr->noPatches] = sbr->k0 - odd -
 635             sbr->patchNoSubbands[sbr->noPatches];
 636
 637         if (sbr->patchNoSubbands[sbr->noPatches] > 0)
 638         {
 639             usb = sb;
 640             msb = sb;
 641             sbr->noPatches++;
 642         } else {
 643             msb = sbr->kx;
 644         }
 645
 646         if (sbr->f_master[k] - sb < 3)
 647             k = sbr->N_master;
 648     } while (sb != (sbr->kx + sbr->M));
 649
 650     if ((sbr->patchNoSubbands[sbr->noPatches-1] < 3) && (sbr->noPatches > 1))
 651     {
 652         sbr->noPatches--;
 653     }
 654
 655     sbr->noPatches = min(sbr->noPatches, 5);
 656 }
 657
 658 #endif