encoder/ixheaace_sbr_freq_scaling.c - platform/external/libxaac - Git at Google

 /******************************************************************************
  *                                                                            *
  * Copyright (C) 2023 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  *****************************************************************************
  * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
  */

 #include <math.h>
 #include "ixheaac_type_def.h"
 #include "ixheaac_constants.h"
 #include "ixheaace_error_codes.h"
 #include "ixheaac_error_standards.h"
 #include "ixheaace_aac_constants.h"
 #include "ixheaac_basic_ops32.h"
 #include "ixheaac_basic_ops16.h"
 #include "ixheaac_basic_ops40.h"
 #include "ixheaac_basic_ops.h"

 #include "ixheaace_common_rom.h"
 #include "ixheaace_sbr_header.h"
 #include "ixheaace_sbr_def.h"
 #include "ixheaace_sbr_freq_scaling.h"
 #include "ixheaace_sbr_misc.h"
 #include "ixheaace_resampler.h"
 #include "ixheaace_sbr_rom.h"

 static WORD32 ixheaace_get_start_freq_4_1(WORD32 fs, WORD32 start_freq) {
   WORD32 minimum_k0;
   const WORD32 *ptr_start_offset;

   switch (fs) {
     case 16000:
       minimum_k0 = 12;
       break;
     case 22050:
       minimum_k0 = 9;
       break;
     case 24000:
       minimum_k0 = 8;
       break;
     case 32000:
       minimum_k0 = 8;
       break;
     case 44100:
       minimum_k0 = 6;
       break;
     case 48000:
       minimum_k0 = 5;
       break;
     default:
       minimum_k0 = 5; /* illegal fs */
   }

   switch (fs) {
     case 16000: {
       ptr_start_offset = &ixheaace_start_freq_16k_4_1[0];
     } break;

     case 22050: {
       ptr_start_offset = &ixheaace_start_freq_22k_4_1[0];
     } break;

     case 24000: {
       ptr_start_offset = &ixheaace_start_freq_24k_4_1[0];
     } break;

     case 32000: {
       ptr_start_offset = &ixheaace_start_freq_32k_4_1[0];
     } break;

     case 44100:
     case 48000:
     case 64000: {
       ptr_start_offset = &ixheaace_start_freq_48k_4_1[0];
     } break;

     case 88200:
     case 96000: {
       ptr_start_offset = &ixheaace_start_freq_96k_4_1[0];
     } break;

     default: {
       ptr_start_offset = &ixheaace_start_freq_dflt_4_1[0];
     }
   }
   return (minimum_k0 + ptr_start_offset[start_freq]);
 }

 static WORD32 ixheaace_get_stop_freq_4_1(WORD32 fs, WORD32 stop_freq) {
   WORD32 result, i;
   WORD32 *v_stop_freq = 0;
   WORD32 k1_min;
   WORD32 v_dstop[13];

   /* counting previous operations */
   switch (fs) {
     case 16000:
       k1_min = 24;
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_16k_4_1[0];
       break;
     case 22050:
       k1_min = 17;
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_22k_4_1[0];
       break;
     case 24000:
       k1_min = 16;
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_24k_4_1[0];
       break;
     case 32000:
       k1_min = 16;
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_32k_4_1[0];
       break;

     case 44100:
       k1_min = 12;
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_44k_4_1[0];
       break;

     case 48000:
       k1_min = 11;
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_48k_4_1[0];
       break;

     default:
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_32k_4_1[0];
       k1_min = 11; /* illegal fs  */
   }

   for (i = 0; i <= 12; i++) {
     v_dstop[i] = v_stop_freq[i + 1] - v_stop_freq[i];
   }

   ixheaace_shellsort_int(v_dstop, 13);

   result = k1_min;

   for (i = 0; i < stop_freq; i++) {
     result = result + v_dstop[i];
   }

   return result;
 }

 static WORD32 ixheaace_get_start_freq(WORD32 fs, WORD32 start_freq) {
   WORD32 minimum_k0;

   switch (fs) {
     case 16000:
       minimum_k0 = 24;
       break;
     case 22050:
       minimum_k0 = 17;
       break;
     case 24000:
       minimum_k0 = 16;
       break;
     case 32000:
       minimum_k0 = 16;
       break;
     case 44100:
       minimum_k0 = 12;
       break;
     case 48000:
       minimum_k0 = 11;
       break;
     case 64000:
       minimum_k0 = 10;
       break;
     case 88200:
       minimum_k0 = 7;
       break;
     case 96000:
       minimum_k0 = 7;
       break;
     default:
       minimum_k0 = 11; /* illegal fs */
   }

   switch (fs) {
     case 16000: {
       return (minimum_k0 + vector_offset_16k[start_freq]);
     } break;

     case 22050: {
       return (minimum_k0 + vector_offset_22k[start_freq]);
     } break;

     case 24000: {
       return (minimum_k0 + vector_offset_24k[start_freq]);
     } break;

     case 32000: {
       return (minimum_k0 + vector_offset_32k[start_freq]);
     } break;

     case 44100:
     case 48000:
     case 64000: {
       return (minimum_k0 + vector_offset_44_48_64[start_freq]);
     } break;

     case 88200:
     case 96000: {
       return (minimum_k0 + vector_offset_88_96[start_freq]);
     } break;

     default: {
       return (minimum_k0 + vector_offset_def[start_freq]);
     }
   }
 }

 static WORD32 ixheaace_get_stop_freq(WORD32 fs, WORD32 stop_freq) {
   WORD32 result, i;
   WORD32 *v_stop_freq = 0;
   WORD32 k1_min;
   WORD32 v_dstop[13];

   switch (fs) {
     case 16000:
       k1_min = ixheaace_stop_freq_16k[0];
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_16k[0];
       break;
     case 22050:
       k1_min = ixheaace_stop_freq_22k[0];
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_22k[0];
       break;
     case 24000:
       k1_min = ixheaace_stop_freq_24k[0];
       v_stop_freq = (WORD32 *)&ixheaace_stop_freq_24k[0];
       break;
     case 32000:
       k1_min = 32;

       v_stop_freq = (WORD32 *)vector_stop_freq_32;
       break;

     case 44100:
       k1_min = 23;

       v_stop_freq = (WORD32 *)vector_stop_freq_44;
       break;

     case 48000:
       k1_min = 21;

       v_stop_freq = (WORD32 *)vector_stop_freq_48;
       break;

     default:
       v_stop_freq = (WORD32 *)vector_stop_freq_32;
       k1_min = 21; /* illegal fs  */
   }

   for (i = 0; i <= 12; i++) {
     v_dstop[i] = v_stop_freq[i + 1] - v_stop_freq[i];
   }

   ixheaace_shellsort_int(v_dstop, 13);

   result = k1_min;

   for (i = 0; i < stop_freq; i++) {
     result = result + v_dstop[i];
   }

   return result;
 }

 static WORD32 ixheaace_get_usac_stop_freq(WORD32 fs, WORD32 stop_freq)
 {
   WORD32 result, i;
   WORD32 *v_stop_freq = 0;
   WORD32 k1_min;
   WORD32 v_dstop[13];

   switch (fs)
   {
   case 16000:
     k1_min = ixheaace_usac_stop_freq_16k[0];
     v_stop_freq = (WORD32 *)&ixheaace_usac_stop_freq_16k[0];
     break;
   case 22050:
     k1_min = ixheaace_usac_stop_freq_22k[0];
     v_stop_freq = (WORD32 *)&ixheaace_usac_stop_freq_22k[0];
     break;
   case 24000:
     k1_min = ixheaace_usac_stop_freq_24k[0];
     v_stop_freq = (WORD32 *)&ixheaace_usac_stop_freq_24k[0];
     break;
   case 32000:
     k1_min = 32;
     v_stop_freq = (WORD32 *)vector_stop_freq_32;
     break;

   case 44100:
     k1_min = 23;
     v_stop_freq = (WORD32 *)vector_stop_freq_44;
     break;

   case 48000:
     k1_min = 21;
     v_stop_freq = (WORD32 *)vector_stop_freq_48;
     break;

   default:
     v_stop_freq = (WORD32 *)vector_stop_freq_32;
     k1_min = 21; /* illegal fs  */
   }

   for (i = 0; i <= 12; i++)
   {
     v_dstop[i] = v_stop_freq[i + 1] - v_stop_freq[i];
   }

   ixheaace_shellsort_int(v_dstop, 13);

   result = k1_min;

   for (i = 0; i < stop_freq; i++)
   {
     result = result + v_dstop[i];
   }

   return result;
 }

 WORD32
 ixheaace_get_sbr_start_freq_raw(WORD32 start_freq, WORD32 qmf_bands, WORD32 fs) {
   WORD32 result;

   if (start_freq < 0 || start_freq > 15) {
     return -1;
   }

   result = ixheaace_get_start_freq(fs, start_freq);

   result = (result * fs / qmf_bands + 1) >> 1;

   return result;
 }

 static WORD32 ixheaace_number_of_bands(WORD32 b_p_o, WORD32 start, WORD32 stop,
                                        FLOAT32 warp_fac) {
   WORD32 result = 0;
   result = (WORD32)(b_p_o * log((FLOAT32)(stop) / start) / (2.0 * log(2.0) * warp_fac) + 0.5);
   result <<= 1;
   return result;
 }

 static VOID ixheaace_calc_bands(WORD32 *ptr_diff, WORD32 start, WORD32 stop, WORD32 num_bands) {
   WORD32 i;
   WORD32 previous;
   WORD32 current;
   previous = start;
   for (i = 1; i <= num_bands; i++) {
     current = (WORD32)((start * pow((FLOAT32)stop / start, (FLOAT32)i / num_bands)) + 0.5f);
     ptr_diff[i - 1] = current - previous;
     previous = current;
   }
 }

 static VOID ixheaace_modify_bands(WORD32 max_band_previous, WORD32 *ptr_diff, WORD32 length) {
   WORD32 change = max_band_previous - ptr_diff[0];

   if (change > (ptr_diff[length - 1] - ptr_diff[0]) / 2) {
     change = (ptr_diff[length - 1] - ptr_diff[0]) / 2;
   }

   ptr_diff[0] += change;

   ptr_diff[length - 1] -= change;

   ixheaace_shellsort_int(ptr_diff, length);
 }

 static VOID ixheaace_cum_sum(WORD32 start_value, WORD32 *ptr_diff, WORD32 length,
                              UWORD8 *ptr_start_adress) {
   WORD32 i;

   ptr_start_adress[0] = (UWORD8)start_value;

   for (i = 1; i <= length; i++) {
     ptr_start_adress[i] = ptr_start_adress[i - 1] + (UWORD8)ptr_diff[i - 1];
   }
 }

 IA_ERRORCODE
 ixheaace_find_start_and_stop_band(const WORD32 sampling_freq, const WORD32 num_channels,
                                   const WORD32 start_freq, const WORD32 stop_freq,
                                   const ixheaace_sr_mode sample_rate_mode, WORD32 *ptr_k0,
                                   WORD32 *ptr_k2, WORD32 sbr_ratio_idx,
                                   ixheaace_sbr_codec_type sbr_codec) {
   switch (sbr_codec) {
     case USAC_SBR: {
       if (sbr_ratio_idx == USAC_SBR_RATIO_INDEX_4_1) {
         *ptr_k0 = ixheaace_get_start_freq_4_1(sampling_freq, start_freq);
       } else {
         *ptr_k0 = ixheaace_get_start_freq(sampling_freq, start_freq);
       }
       break;
     }
     default: {
       *ptr_k0 = ixheaace_get_start_freq(sampling_freq, start_freq);
       break;
     }
   }
   if ((sample_rate_mode == 1) && (sampling_freq * num_channels < 2 * *ptr_k0 * sampling_freq)) {
     return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_SAMPLERATE_MODE;
   }

   if (stop_freq < 14) {
     switch (sbr_codec) {
       case USAC_SBR: {
         if (USAC_SBR_RATIO_INDEX_4_1 == sbr_ratio_idx) {
           *ptr_k2 = ixheaace_get_stop_freq_4_1(sampling_freq, stop_freq);
         } else {
           *ptr_k2 = ixheaace_get_usac_stop_freq(sampling_freq, stop_freq);
         }
         break;
       }
       default: {
         *ptr_k2 = ixheaace_get_stop_freq(sampling_freq, stop_freq);
         break;
       }
     }
   }

   else {
     *ptr_k2 = (stop_freq == 14 ? 2 * *ptr_k0 : 3 * *ptr_k0);
   }

   if (*ptr_k2 > num_channels) {
     *ptr_k2 = num_channels;
   }
   if (sbr_codec == USAC_SBR) {
     if (sbr_ratio_idx == USAC_SBR_RATIO_INDEX_4_1) {
       if (((*ptr_k2 - *ptr_k0) > MAXIMUM_FREQ_COEFFS_USAC) || (*ptr_k2 <= *ptr_k0)) {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
       }
       if ((2 * sampling_freq == 44100) && ((*ptr_k2 - *ptr_k0) > MAXIMUM_FREQ_COEFFS_USAC)) {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
       }
       if ((2 * sampling_freq >= 48000) && ((*ptr_k2 - *ptr_k0) > MAXIMUM_FREQ_COEFFS_USAC)) {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
       }
     } else {
       if (sampling_freq <= 32000) {
         if ((*ptr_k2 - *ptr_k0) > MAXIMUM_FREQ_COEFFS_LE32KHZ) {
           return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
         }
       } else if (sampling_freq == 44100) {
         if ((*ptr_k2 - *ptr_k0) > MAXIMUM_FREQ_COEFFS_EQ44KHZ) {
           return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
         }
       } else if (sampling_freq >= 48000) {
         if ((*ptr_k2 - *ptr_k0) > MAXIMUM_FREQ_COEFFS_GE48KHZ) {
           return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
         }
       } else {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
       }
     }
   } else {
     if (sampling_freq <= 32000) {
       if ((*ptr_k2 - *ptr_k0) > MAXIMUM_FREQ_COEFFS_LE32KHZ) {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
       }
     } else if (sampling_freq == 44100) {
       if ((*ptr_k2 - *ptr_k0) > MAXIMUM_FREQ_COEFFS_EQ44KHZ) {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
       }
     } else if (sampling_freq >= 48000) {
       if ((*ptr_k2 - *ptr_k0) > MAXIMUM_FREQ_COEFFS_GE48KHZ) {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
       }
     } else {
       return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
     }
   }

   if ((*ptr_k2 - *ptr_k0) < 0) {
     return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
   }

   return IA_NO_ERROR;
 }

 IA_ERRORCODE
 ixheaace_update_freq_scale(UWORD8 *ptr_k_master, WORD32 *ptr_num_bands, const WORD32 k0,
                            const WORD32 k2, const WORD32 freq_scale, const WORD32 alter_scale,
                            ixheaace_sr_mode sbr_rate)

 {
   IA_ERRORCODE err_code = IA_NO_ERROR;
   WORD32 b_p_o = 0;
   WORD32 dk = 0;

   FLOAT32 warp;
   WORD32 k1 = 0, i;
   WORD32 num_bands0;
   WORD32 num_bands1;
   WORD32 diff_tot[IXHEAACE_MAXIMUM_OCTAVE + IXHEAACE_MAXIMUM_SECOND_REGION] = {0};
   WORD32 *diff0 = diff_tot;
   WORD32 *diff1 = diff_tot + IXHEAACE_MAXIMUM_OCTAVE;
   WORD32 k2_achived;
   WORD32 k2_diff;
   WORD32 incr = 0;

   switch (freq_scale) {
     case 1:
       b_p_o = 12;
       break;
     case 2:
       b_p_o = 10;
       break;
     case 3:
       b_p_o = 8;
       break;
   }

   if (freq_scale > 0) {
     if (alter_scale == 0) {
       warp = 1.0f;
     } else {
       warp = 1.3f;
     }

     if (IXHEAACE_QUAD_RATE == sbr_rate) {
       if (k0 < b_p_o) {
         b_p_o = (k0 >> 1) * 2;
       }
     }

     if (4 * k2 >= 9 * k0) {
       k1 = 2 * k0;
       num_bands0 = ixheaace_number_of_bands(b_p_o, k0, k1, 1.0f);
       num_bands1 = ixheaace_number_of_bands(b_p_o, k1, k2, warp);

       ixheaace_calc_bands(diff0, k0, k1, num_bands0);
       ixheaace_shellsort_int(diff0, num_bands0);

       if (diff0[0] == 0) {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_NUM_BANDS;
       }

       ixheaace_cum_sum(k0, diff0, num_bands0, ptr_k_master);

       ixheaace_calc_bands(diff1, k1, k2, num_bands1);
       ixheaace_shellsort_int(diff1, num_bands1);

       if (diff0[num_bands0 - 1] > diff1[0]) {
         ixheaace_modify_bands(diff0[num_bands0 - 1], diff1, num_bands1);
       }

       ixheaace_cum_sum(k1, diff1, num_bands1, &ptr_k_master[num_bands0]);
       *ptr_num_bands = num_bands0 + num_bands1;
     } else {
       k1 = k2;
       num_bands0 = ixheaace_number_of_bands(b_p_o, k0, k1, 1.0f);

       ixheaace_calc_bands(diff0, k0, k1, num_bands0);
       ixheaace_shellsort_int(diff0, num_bands0);

       if (diff0[0] == 0) {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_NUM_BANDS;
       }

       ixheaace_cum_sum(k0, diff0, num_bands0, ptr_k_master);

       *ptr_num_bands = num_bands0;
     }
   } else {
     if (alter_scale == 0) {
       dk = 1;
       num_bands0 = 2 * ((k2 - k0) / 2);
     } else {
       dk = 2;
       num_bands0 = 2 * (((k2 - k0) / dk + 1) / 2);
     }

     k2_achived = k0 + num_bands0 * dk;
     k2_diff = k2 - k2_achived;

     for (i = 0; i < num_bands0; i++) {
       diff_tot[i] = dk;
     }

     if (k2_diff < 0) {
       incr = 1;
       i = 0;
     }

     if (k2_diff > 0) {
       incr = -1;

       i = num_bands0 - 1;
     }

     while (k2_diff != 0) {
       if (i < 0) break;
       diff_tot[i] = diff_tot[i] - incr;

       i = i + incr;

       k2_diff = k2_diff + incr;
     }

     ixheaace_cum_sum(k0, diff_tot, num_bands0, ptr_k_master);

     *ptr_num_bands = num_bands0;
   }

   if (*ptr_num_bands < 1) {
     return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_NUM_BANDS;
   }

   if (sbr_rate == IXHEAACE_QUAD_RATE) {
     for (i = 1; i < *ptr_num_bands; i++) {
       if (!(ptr_k_master[i] - ptr_k_master[i - 1] <= k0 - 2)) {
         return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_NUM_BANDS;
       }
     }
   }

   return err_code;
 }

 VOID ixheaace_update_high_res(UWORD8 *ptr_hires, WORD32 *ptr_num_hires, UWORD8 *ptr_k_master,
                               WORD32 num_master, WORD32 *ptr_xover_band,
                               ixheaace_sr_mode dr_or_sr, WORD32 num_qmf_ch) {
   WORD32 i;
   WORD32 divider;
   WORD32 max1, max2;

   divider = (dr_or_sr == IXHEAACE_DUAL_RATE) ? 2 : 1;
   if (dr_or_sr == IXHEAACE_QUAD_RATE) {
     divider = 4;
   }

   if ((ptr_k_master[*ptr_xover_band] > (num_qmf_ch / divider)) ||
       (*ptr_xover_band > num_master)) {
     max1 = 0;
     max2 = num_master;

     while ((ptr_k_master[max1 + 1] < (num_qmf_ch / divider)) && ((max1 + 1) < max2)) {
       max1++;
     }

     *ptr_xover_band = max1;
   }

   *ptr_num_hires = num_master - *ptr_xover_band;

   for (i = *ptr_xover_band; i <= num_master; i++) {
     ptr_hires[i - *ptr_xover_band] = ptr_k_master[i];
   }
 }

 VOID ixheaace_update_low_res(UWORD8 *ptr_lores, WORD32 *ptr_num_lores, UWORD8 *ptr_hires,
                              WORD32 ptr_num_hires) {
   WORD32 i;

   if (ptr_num_hires % 2 == 0) {
     *ptr_num_lores = ptr_num_hires / 2;

     for (i = 0; i <= *ptr_num_lores; i++) {
       ptr_lores[i] = ptr_hires[i * 2];
     }
   } else {
     *ptr_num_lores = (ptr_num_hires + 1) / 2;

     ptr_lores[0] = ptr_hires[0];

     for (i = 1; i <= *ptr_num_lores; i++) {
       ptr_lores[i] = ptr_hires[i * 2 - 1];
     }
   }
 }
	/******************************************************************************
	* *
	* Copyright (C) 2023 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*
	*****************************************************************************
	* Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
	*/

	#include <math.h>
	#include "ixheaac_type_def.h"
	#include "ixheaac_constants.h"
	#include "ixheaace_error_codes.h"
	#include "ixheaac_error_standards.h"
	#include "ixheaace_aac_constants.h"
	#include "ixheaac_basic_ops32.h"
	#include "ixheaac_basic_ops16.h"
	#include "ixheaac_basic_ops40.h"
	#include "ixheaac_basic_ops.h"

	#include "ixheaace_common_rom.h"
	#include "ixheaace_sbr_header.h"
	#include "ixheaace_sbr_def.h"
	#include "ixheaace_sbr_freq_scaling.h"
	#include "ixheaace_sbr_misc.h"
	#include "ixheaace_resampler.h"
	#include "ixheaace_sbr_rom.h"

	static WORD32 ixheaace_get_start_freq_4_1(WORD32 fs, WORD32 start_freq) {
	WORD32 minimum_k0;
	const WORD32 *ptr_start_offset;

	switch (fs) {
	case 16000:
	minimum_k0 = 12;
	break;
	case 22050:
	minimum_k0 = 9;
	break;
	case 24000:
	minimum_k0 = 8;
	break;
	case 32000:
	minimum_k0 = 8;
	break;
	case 44100:
	minimum_k0 = 6;
	break;
	case 48000:
	minimum_k0 = 5;
	break;
	default:
	minimum_k0 = 5; /* illegal fs */
	}

	switch (fs) {
	case 16000: {
	ptr_start_offset = &ixheaace_start_freq_16k_4_1[0];
	} break;

	case 22050: {
	ptr_start_offset = &ixheaace_start_freq_22k_4_1[0];
	} break;

	case 24000: {
	ptr_start_offset = &ixheaace_start_freq_24k_4_1[0];
	} break;

	case 32000: {
	ptr_start_offset = &ixheaace_start_freq_32k_4_1[0];
	} break;

	case 44100:
	case 48000:
	case 64000: {
	ptr_start_offset = &ixheaace_start_freq_48k_4_1[0];
	} break;

	case 88200:
	case 96000: {
	ptr_start_offset = &ixheaace_start_freq_96k_4_1[0];
	} break;

	default: {
	ptr_start_offset = &ixheaace_start_freq_dflt_4_1[0];
	}
	}
	return (minimum_k0 + ptr_start_offset[start_freq]);
	}

	static WORD32 ixheaace_get_stop_freq_4_1(WORD32 fs, WORD32 stop_freq) {
	WORD32 result, i;
	WORD32 *v_stop_freq = 0;
	WORD32 k1_min;
	WORD32 v_dstop[13];

	/* counting previous operations */
	switch (fs) {
	case 16000:
	k1_min = 24;
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_16k_4_1[0];
	break;
	case 22050:
	k1_min = 17;
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_22k_4_1[0];
	break;
	case 24000:
	k1_min = 16;
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_24k_4_1[0];
	break;
	case 32000:
	k1_min = 16;
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_32k_4_1[0];
	break;

	case 44100:
	k1_min = 12;
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_44k_4_1[0];
	break;

	case 48000:
	k1_min = 11;
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_48k_4_1[0];
	break;

	default:
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_32k_4_1[0];
	k1_min = 11; /* illegal fs */
	}

	for (i = 0; i <= 12; i++) {
	v_dstop[i] = v_stop_freq[i + 1] - v_stop_freq[i];
	}

	ixheaace_shellsort_int(v_dstop, 13);

	result = k1_min;

	for (i = 0; i < stop_freq; i++) {
	result = result + v_dstop[i];
	}

	return result;
	}

	static WORD32 ixheaace_get_start_freq(WORD32 fs, WORD32 start_freq) {
	WORD32 minimum_k0;

	switch (fs) {
	case 16000:
	minimum_k0 = 24;
	break;
	case 22050:
	minimum_k0 = 17;
	break;
	case 24000:
	minimum_k0 = 16;
	break;
	case 32000:
	minimum_k0 = 16;
	break;
	case 44100:
	minimum_k0 = 12;
	break;
	case 48000:
	minimum_k0 = 11;
	break;
	case 64000:
	minimum_k0 = 10;
	break;
	case 88200:
	minimum_k0 = 7;
	break;
	case 96000:
	minimum_k0 = 7;
	break;
	default:
	minimum_k0 = 11; /* illegal fs */
	}

	switch (fs) {
	case 16000: {
	return (minimum_k0 + vector_offset_16k[start_freq]);
	} break;

	case 22050: {
	return (minimum_k0 + vector_offset_22k[start_freq]);
	} break;

	case 24000: {
	return (minimum_k0 + vector_offset_24k[start_freq]);
	} break;

	case 32000: {
	return (minimum_k0 + vector_offset_32k[start_freq]);
	} break;

	case 44100:
	case 48000:
	case 64000: {
	return (minimum_k0 + vector_offset_44_48_64[start_freq]);
	} break;

	case 88200:
	case 96000: {
	return (minimum_k0 + vector_offset_88_96[start_freq]);
	} break;

	default: {
	return (minimum_k0 + vector_offset_def[start_freq]);
	}
	}
	}

	static WORD32 ixheaace_get_stop_freq(WORD32 fs, WORD32 stop_freq) {
	WORD32 result, i;
	WORD32 *v_stop_freq = 0;
	WORD32 k1_min;
	WORD32 v_dstop[13];

	switch (fs) {
	case 16000:
	k1_min = ixheaace_stop_freq_16k[0];
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_16k[0];
	break;
	case 22050:
	k1_min = ixheaace_stop_freq_22k[0];
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_22k[0];
	break;
	case 24000:
	k1_min = ixheaace_stop_freq_24k[0];
	v_stop_freq = (WORD32 *)&ixheaace_stop_freq_24k[0];
	break;
	case 32000:
	k1_min = 32;

	v_stop_freq = (WORD32 *)vector_stop_freq_32;
	break;

	case 44100:
	k1_min = 23;

	v_stop_freq = (WORD32 *)vector_stop_freq_44;
	break;

	case 48000:
	k1_min = 21;

	v_stop_freq = (WORD32 *)vector_stop_freq_48;
	break;

	default:
	v_stop_freq = (WORD32 *)vector_stop_freq_32;
	k1_min = 21; /* illegal fs */
	}

	for (i = 0; i <= 12; i++) {
	v_dstop[i] = v_stop_freq[i + 1] - v_stop_freq[i];
	}

	ixheaace_shellsort_int(v_dstop, 13);

	result = k1_min;

	for (i = 0; i < stop_freq; i++) {
	result = result + v_dstop[i];
	}

	return result;
	}

	static WORD32 ixheaace_get_usac_stop_freq(WORD32 fs, WORD32 stop_freq)
	{
	WORD32 result, i;
	WORD32 *v_stop_freq = 0;
	WORD32 k1_min;
	WORD32 v_dstop[13];

	switch (fs)
	{
	case 16000:
	k1_min = ixheaace_usac_stop_freq_16k[0];
	v_stop_freq = (WORD32 *)&ixheaace_usac_stop_freq_16k[0];
	break;
	case 22050:
	k1_min = ixheaace_usac_stop_freq_22k[0];
	v_stop_freq = (WORD32 *)&ixheaace_usac_stop_freq_22k[0];
	break;
	case 24000:
	k1_min = ixheaace_usac_stop_freq_24k[0];
	v_stop_freq = (WORD32 *)&ixheaace_usac_stop_freq_24k[0];
	break;
	case 32000:
	k1_min = 32;
	v_stop_freq = (WORD32 *)vector_stop_freq_32;
	break;

	case 44100:
	k1_min = 23;
	v_stop_freq = (WORD32 *)vector_stop_freq_44;
	break;

	case 48000:
	k1_min = 21;
	v_stop_freq = (WORD32 *)vector_stop_freq_48;
	break;

	default:
	v_stop_freq = (WORD32 *)vector_stop_freq_32;
	k1_min = 21; /* illegal fs */
	}

	for (i = 0; i <= 12; i++)
	{
	v_dstop[i] = v_stop_freq[i + 1] - v_stop_freq[i];
	}

	ixheaace_shellsort_int(v_dstop, 13);

	result = k1_min;

	for (i = 0; i < stop_freq; i++)
	{
	result = result + v_dstop[i];
	}

	return result;
	}

	WORD32
	ixheaace_get_sbr_start_freq_raw(WORD32 start_freq, WORD32 qmf_bands, WORD32 fs) {
	WORD32 result;

	if (start_freq < 0 \|\| start_freq > 15) {
	return -1;
	}

	result = ixheaace_get_start_freq(fs, start_freq);

	result = (result * fs / qmf_bands + 1) >> 1;

	return result;
	}

	static WORD32 ixheaace_number_of_bands(WORD32 b_p_o, WORD32 start, WORD32 stop,
	FLOAT32 warp_fac) {
	WORD32 result = 0;
	result = (WORD32)(b_p_o * log((FLOAT32)(stop) / start) / (2.0 * log(2.0) * warp_fac) + 0.5);
	result <<= 1;
	return result;
	}

	static VOID ixheaace_calc_bands(WORD32 *ptr_diff, WORD32 start, WORD32 stop, WORD32 num_bands) {
	WORD32 i;
	WORD32 previous;
	WORD32 current;
	previous = start;
	for (i = 1; i <= num_bands; i++) {
	current = (WORD32)((start * pow((FLOAT32)stop / start, (FLOAT32)i / num_bands)) + 0.5f);
	ptr_diff[i - 1] = current - previous;
	previous = current;
	}
	}

	static VOID ixheaace_modify_bands(WORD32 max_band_previous, WORD32 *ptr_diff, WORD32 length) {
	WORD32 change = max_band_previous - ptr_diff[0];

	if (change > (ptr_diff[length - 1] - ptr_diff[0]) / 2) {
	change = (ptr_diff[length - 1] - ptr_diff[0]) / 2;
	}

	ptr_diff[0] += change;

	ptr_diff[length - 1] -= change;

	ixheaace_shellsort_int(ptr_diff, length);
	}

	static VOID ixheaace_cum_sum(WORD32 start_value, WORD32 *ptr_diff, WORD32 length,
	UWORD8 *ptr_start_adress) {
	WORD32 i;

	ptr_start_adress[0] = (UWORD8)start_value;

	for (i = 1; i <= length; i++) {
	ptr_start_adress[i] = ptr_start_adress[i - 1] + (UWORD8)ptr_diff[i - 1];
	}
	}

	IA_ERRORCODE
	ixheaace_find_start_and_stop_band(const WORD32 sampling_freq, const WORD32 num_channels,
	const WORD32 start_freq, const WORD32 stop_freq,
	const ixheaace_sr_mode sample_rate_mode, WORD32 *ptr_k0,
	WORD32 *ptr_k2, WORD32 sbr_ratio_idx,
	ixheaace_sbr_codec_type sbr_codec) {
	switch (sbr_codec) {
	case USAC_SBR: {
	if (sbr_ratio_idx == USAC_SBR_RATIO_INDEX_4_1) {
	*ptr_k0 = ixheaace_get_start_freq_4_1(sampling_freq, start_freq);
	} else {
	*ptr_k0 = ixheaace_get_start_freq(sampling_freq, start_freq);
	}
	break;
	}
	default: {
	*ptr_k0 = ixheaace_get_start_freq(sampling_freq, start_freq);
	break;
	}
	}
	if ((sample_rate_mode == 1) && (sampling_freq * num_channels < 2 * ptr_k0 sampling_freq)) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_SAMPLERATE_MODE;
	}

	if (stop_freq < 14) {
	switch (sbr_codec) {
	case USAC_SBR: {
	if (USAC_SBR_RATIO_INDEX_4_1 == sbr_ratio_idx) {
	*ptr_k2 = ixheaace_get_stop_freq_4_1(sampling_freq, stop_freq);
	} else {
	*ptr_k2 = ixheaace_get_usac_stop_freq(sampling_freq, stop_freq);
	}
	break;
	}
	default: {
	*ptr_k2 = ixheaace_get_stop_freq(sampling_freq, stop_freq);
	break;
	}
	}
	}

	else {
	ptr_k2 = (stop_freq == 14 ? 2 ptr_k0 : 3 *ptr_k0);
	}

	if (*ptr_k2 > num_channels) {
	*ptr_k2 = num_channels;
	}
	if (sbr_codec == USAC_SBR) {
	if (sbr_ratio_idx == USAC_SBR_RATIO_INDEX_4_1) {
	if (((ptr_k2 - ptr_k0) > MAXIMUM_FREQ_COEFFS_USAC) \|\| (ptr_k2 <= ptr_k0)) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	if ((2 * sampling_freq == 44100) && ((ptr_k2 - ptr_k0) > MAXIMUM_FREQ_COEFFS_USAC)) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	if ((2 * sampling_freq >= 48000) && ((ptr_k2 - ptr_k0) > MAXIMUM_FREQ_COEFFS_USAC)) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	} else {
	if (sampling_freq <= 32000) {
	if ((ptr_k2 - ptr_k0) > MAXIMUM_FREQ_COEFFS_LE32KHZ) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	} else if (sampling_freq == 44100) {
	if ((ptr_k2 - ptr_k0) > MAXIMUM_FREQ_COEFFS_EQ44KHZ) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	} else if (sampling_freq >= 48000) {
	if ((ptr_k2 - ptr_k0) > MAXIMUM_FREQ_COEFFS_GE48KHZ) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	} else {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	}
	} else {
	if (sampling_freq <= 32000) {
	if ((ptr_k2 - ptr_k0) > MAXIMUM_FREQ_COEFFS_LE32KHZ) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	} else if (sampling_freq == 44100) {
	if ((ptr_k2 - ptr_k0) > MAXIMUM_FREQ_COEFFS_EQ44KHZ) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	} else if (sampling_freq >= 48000) {
	if ((ptr_k2 - ptr_k0) > MAXIMUM_FREQ_COEFFS_GE48KHZ) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	} else {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}
	}

	if ((ptr_k2 - ptr_k0) < 0) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_FREQ_COEFFS;
	}

	return IA_NO_ERROR;
	}

	IA_ERRORCODE
	ixheaace_update_freq_scale(UWORD8 ptr_k_master, WORD32 ptr_num_bands, const WORD32 k0,
	const WORD32 k2, const WORD32 freq_scale, const WORD32 alter_scale,
	ixheaace_sr_mode sbr_rate)

	{
	IA_ERRORCODE err_code = IA_NO_ERROR;
	WORD32 b_p_o = 0;
	WORD32 dk = 0;

	FLOAT32 warp;
	WORD32 k1 = 0, i;
	WORD32 num_bands0;
	WORD32 num_bands1;
	WORD32 diff_tot[IXHEAACE_MAXIMUM_OCTAVE + IXHEAACE_MAXIMUM_SECOND_REGION] = {0};
	WORD32 *diff0 = diff_tot;
	WORD32 *diff1 = diff_tot + IXHEAACE_MAXIMUM_OCTAVE;
	WORD32 k2_achived;
	WORD32 k2_diff;
	WORD32 incr = 0;

	switch (freq_scale) {
	case 1:
	b_p_o = 12;
	break;
	case 2:
	b_p_o = 10;
	break;
	case 3:
	b_p_o = 8;
	break;
	}

	if (freq_scale > 0) {
	if (alter_scale == 0) {
	warp = 1.0f;
	} else {
	warp = 1.3f;
	}

	if (IXHEAACE_QUAD_RATE == sbr_rate) {
	if (k0 < b_p_o) {
	b_p_o = (k0 >> 1) * 2;
	}
	}

	if (4 * k2 >= 9 * k0) {
	k1 = 2 * k0;
	num_bands0 = ixheaace_number_of_bands(b_p_o, k0, k1, 1.0f);
	num_bands1 = ixheaace_number_of_bands(b_p_o, k1, k2, warp);

	ixheaace_calc_bands(diff0, k0, k1, num_bands0);
	ixheaace_shellsort_int(diff0, num_bands0);

	if (diff0[0] == 0) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_NUM_BANDS;
	}

	ixheaace_cum_sum(k0, diff0, num_bands0, ptr_k_master);

	ixheaace_calc_bands(diff1, k1, k2, num_bands1);
	ixheaace_shellsort_int(diff1, num_bands1);

	if (diff0[num_bands0 - 1] > diff1[0]) {
	ixheaace_modify_bands(diff0[num_bands0 - 1], diff1, num_bands1);
	}

	ixheaace_cum_sum(k1, diff1, num_bands1, &ptr_k_master[num_bands0]);
	*ptr_num_bands = num_bands0 + num_bands1;
	} else {
	k1 = k2;
	num_bands0 = ixheaace_number_of_bands(b_p_o, k0, k1, 1.0f);

	ixheaace_calc_bands(diff0, k0, k1, num_bands0);
	ixheaace_shellsort_int(diff0, num_bands0);

	if (diff0[0] == 0) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_NUM_BANDS;
	}

	ixheaace_cum_sum(k0, diff0, num_bands0, ptr_k_master);

	*ptr_num_bands = num_bands0;
	}
	} else {
	if (alter_scale == 0) {
	dk = 1;
	num_bands0 = 2 * ((k2 - k0) / 2);
	} else {
	dk = 2;
	num_bands0 = 2 * (((k2 - k0) / dk + 1) / 2);
	}

	k2_achived = k0 + num_bands0 * dk;
	k2_diff = k2 - k2_achived;

	for (i = 0; i < num_bands0; i++) {
	diff_tot[i] = dk;
	}

	if (k2_diff < 0) {
	incr = 1;
	i = 0;
	}

	if (k2_diff > 0) {
	incr = -1;

	i = num_bands0 - 1;
	}

	while (k2_diff != 0) {
	if (i < 0) break;
	diff_tot[i] = diff_tot[i] - incr;

	i = i + incr;

	k2_diff = k2_diff + incr;
	}

	ixheaace_cum_sum(k0, diff_tot, num_bands0, ptr_k_master);

	*ptr_num_bands = num_bands0;
	}

	if (*ptr_num_bands < 1) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_NUM_BANDS;
	}

	if (sbr_rate == IXHEAACE_QUAD_RATE) {
	for (i = 1; i < *ptr_num_bands; i++) {
	if (!(ptr_k_master[i] - ptr_k_master[i - 1] <= k0 - 2)) {
	return IA_EXHEAACE_INIT_FATAL_SBR_INVALID_NUM_BANDS;
	}
	}
	}

	return err_code;
	}

	VOID ixheaace_update_high_res(UWORD8 ptr_hires, WORD32 ptr_num_hires, UWORD8 *ptr_k_master,
	WORD32 num_master, WORD32 *ptr_xover_band,
	ixheaace_sr_mode dr_or_sr, WORD32 num_qmf_ch) {
	WORD32 i;
	WORD32 divider;
	WORD32 max1, max2;

	divider = (dr_or_sr == IXHEAACE_DUAL_RATE) ? 2 : 1;
	if (dr_or_sr == IXHEAACE_QUAD_RATE) {
	divider = 4;
	}

	if ((ptr_k_master[*ptr_xover_band] > (num_qmf_ch / divider)) \|\|
	(*ptr_xover_band > num_master)) {
	max1 = 0;
	max2 = num_master;

	while ((ptr_k_master[max1 + 1] < (num_qmf_ch / divider)) && ((max1 + 1) < max2)) {
	max1++;
	}

	*ptr_xover_band = max1;
	}

	ptr_num_hires = num_master - ptr_xover_band;

	for (i = *ptr_xover_band; i <= num_master; i++) {
	ptr_hires[i - *ptr_xover_band] = ptr_k_master[i];
	}
	}

	VOID ixheaace_update_low_res(UWORD8 ptr_lores, WORD32 ptr_num_lores, UWORD8 *ptr_hires,
	WORD32 ptr_num_hires) {
	WORD32 i;

	if (ptr_num_hires % 2 == 0) {
	*ptr_num_lores = ptr_num_hires / 2;

	for (i = 0; i <= *ptr_num_lores; i++) {
	ptr_lores[i] = ptr_hires[i * 2];
	}
	} else {
	*ptr_num_lores = (ptr_num_hires + 1) / 2;

	ptr_lores[0] = ptr_hires[0];

	for (i = 1; i <= *ptr_num_lores; i++) {
	ptr_lores[i] = ptr_hires[i * 2 - 1];
	}
	}
	}