/******************************************************************************

 *                                                                            *

 * 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 <string.h>

#include <math.h>

#include "iusace_type_def.h"

#include "ixheaac_error_standards.h"

#include "ixheaace_error_codes.h"

#include "ixheaace_mps_common_define.h"

#include "iusace_cnst.h"

#include "iusace_block_switch_const.h"

#include "iusace_bitbuffer.h"

#include "impd_drc_common_enc.h"

#include "impd_drc_uni_drc.h"

#include "impd_drc_api.h"

#include "impd_drc_uni_drc_eq.h"

#include "impd_drc_uni_drc_filter_bank.h"

#include "impd_drc_gain_enc.h"

#include "impd_drc_struct_def.h"

#include "ixheaace_memory_standards.h"

#include "iusace_tns_usac.h"

#include "iusace_psy_mod.h"

#include "iusace_config.h"

#include "iusace_ms.h"

#include "ixheaace_adjust_threshold_data.h"

#include "iusace_fd_qc_util.h"

#include "iusace_arith_enc.h"

#include "iusace_fd_quant.h"

#include "iusace_signal_classifier.h"

#include "iusace_block_switch_struct_def.h"

#include "ixheaace_sbr_header.h"

#include "ixheaace_config.h"

#include "ixheaace_asc_write.h"

#include "iusace_main.h"

#include "iusace_write_bitstream.h"

#include "ixheaace_nf.h"

#include "iusace_fd_qc_adjthr.h"

#include "iusace_block_switch_const.h"

#include "iusace_rom.h"

#include "ixheaace_cplx_pred.h"

#include "ixheaace_aac_constants.h"

static WORD32 iusace_window_shape[5] = {WIN_SEL_1, WIN_SEL_0, WIN_SEL_0, WIN_SEL_1, WIN_SEL_0};

static WORD32 iusace_count_ms_bits(WORD32 sfb_count, WORD32 sfb_per_grp, WORD32 max_sfb_per_grp) {

  WORD32 ms_bits = 0, sfb_offs, sfb;

  for (sfb_offs = 0; sfb_offs < sfb_count; sfb_offs += sfb_per_grp) {

    for (sfb = 0; sfb < max_sfb_per_grp; sfb++) {

      ms_bits++;

    }

  }

  return (ms_bits);

}

static WORD32 iusace_count_static_bits(ia_usac_data_struct *ptr_usac_data,

                                       ia_usac_encoder_config_struct *ptr_usac_config,

                                       ia_sfb_params_struct *pstr_sfb_params,

                                       ia_psy_mod_out_data_struct *pstr_psy_out, WORD32 channels,

                                       WORD32 chn, WORD32 usac_independency_flag, WORD32 ele_id) {

  WORD32 ms_mask = ptr_usac_data->str_ms_info[chn].ms_mask;

  WORD32 noise_filling = ptr_usac_data->noise_filling[ele_id];

  WORD32 stat_bits = 0, i;

  WORD32 tns_active = 0, tns_present_both = 0;

  WORD32 max_sfb = pstr_psy_out[chn].max_sfb_per_grp;

  (VOID) ptr_usac_config;

  if (channels == 1) {

    stat_bits += 1;  // core mode

    stat_bits += 1;  // tns active

    switch (pstr_psy_out[chn].window_sequence) {

      case ONLY_LONG_SEQUENCE:

      case LONG_START_SEQUENCE:

      case LONG_STOP_SEQUENCE:

        stat_bits += SI_ICS_INFO_BITS_LONG;

        break;

      case EIGHT_SHORT_SEQUENCE:

        stat_bits += SI_ICS_INFO_BITS_SHORT;

        break;

    }

  } else {

    stat_bits += 2;  // core mode

    stat_bits += 2;  // tns and common window

    switch (pstr_psy_out[chn].window_sequence) {

      case ONLY_LONG_SEQUENCE:

      case LONG_START_SEQUENCE:

      case LONG_STOP_SEQUENCE:

        stat_bits += SI_ICS_INFO_BITS_LONG;

        break;

      case EIGHT_SHORT_SEQUENCE:

        stat_bits += SI_ICS_INFO_BITS_SHORT;

        break;

    }

    stat_bits += 1;  // common_max_sfb

    stat_bits += SI_CPE_MS_MASK_BITS;

    if (ms_mask != 3) {

      if (ms_mask == 1) {

        stat_bits += iusace_count_ms_bits(pstr_psy_out[chn].sfb_count,

                                          pstr_psy_out[chn].sfb_per_group, max_sfb);

      }

    } else {

      stat_bits += iusace_write_cplx_pred_data(

          NULL, pstr_sfb_params->num_window_groups[chn], max_sfb,

          ptr_usac_data->complex_coef[chn], ptr_usac_data->pred_coef_re[chn],

          ptr_usac_data->pred_coef_im[chn], iusace_huffman_code_table, usac_independency_flag,

          ptr_usac_data->pred_dir_idx[chn], ptr_usac_data->cplx_pred_used[chn],

          ptr_usac_data->cplx_pred_all[chn], ptr_usac_data->temp_pred_coef_re_prev[chn],

          ptr_usac_data->temp_pred_coef_im_prev[chn], &ptr_usac_data->delta_code_time[chn]);

    }

    if (ptr_usac_data->pstr_tns_info[chn] != NULL &&

        ptr_usac_data->pstr_tns_info[chn + 1] != NULL) {

      tns_active = ptr_usac_data->pstr_tns_info[chn]->tns_data_present ||

                   ptr_usac_data->pstr_tns_info[chn + 1]->tns_data_present;

      tns_present_both = ptr_usac_data->pstr_tns_info[chn]->tns_data_present &&

                         ptr_usac_data->pstr_tns_info[chn + 1]->tns_data_present;

    }

    if (tns_active) {

      stat_bits += 1;  // common_tns

      stat_bits += 1;  // tns_present_both

      if (!tns_present_both) {

        stat_bits += 1;  // tns_data_present1

      }

    }

  }

  for (i = chn; i < chn + channels; i++) {

    stat_bits += 8;  // global_gain

    if (noise_filling) {

      stat_bits += 8;

    }

  }

  for (i = chn; i < chn + channels; i++) {

    if (ptr_usac_data->pstr_tns_info[i] != NULL &&

        ptr_usac_data->pstr_tns_info[i]->tns_data_present == 1) {

      stat_bits += iusace_write_tns_data(NULL, ptr_usac_data->pstr_tns_info[i],

                                         pstr_psy_out[i].window_sequence, 0);

    }

    if (!usac_independency_flag) {

      stat_bits += 1;  // arith_reset_flag

    }

    stat_bits += 1;  // fac_data_present

    stat_bits += ptr_usac_data->str_scratch.ptr_num_fac_bits[i];

  }

  stat_bits += (ptr_usac_data->num_sbr_bits + ptr_usac_data->num_drc_bits);

  return stat_bits;

}

static VOID iusace_sort_for_grouping(WORD32 *sfb_offset, const WORD32 *sfb_width_table,

                                     FLOAT64 *ptr_scratch, FLOAT64 *ptr_spec,

                                     WORD32 num_window_groups, const WORD32 *window_group_length,

                                     WORD32 nr_of_sfb, WORD32 ccfl) {

  WORD32 i, j, ii;

  WORD32 index = 0;

  WORD32 group_offset = 0;

  WORD32 k = 0;

  WORD32 frame_len_short = (ccfl * FRAME_LEN_SHORT_128) / FRAME_LEN_LONG;

  sfb_offset[k] = 0;

  for (k = 1; k < nr_of_sfb + 1; k++) {

    sfb_offset[k] = sfb_offset[k - 1] + sfb_width_table[k - 1];

  }

  index = 0;

  group_offset = 0;

  for (i = 0; i < num_window_groups; i++) {

    for (k = 0; k < nr_of_sfb; k++) {

      for (j = 0; j < window_group_length[i]; j++) {

        for (ii = 0; ii < sfb_width_table[k]; ii++) {

          ptr_scratch[index++] =

              ptr_spec[ii + sfb_offset[k] + frame_len_short * j + group_offset];

        }

      }

    }

    group_offset += frame_len_short * window_group_length[i];

  }

  memcpy(ptr_spec, ptr_scratch, ccfl * sizeof(ptr_spec[0]));

  index = 0;

  sfb_offset[index++] = 0;

  for (i = 0; i < num_window_groups; i++) {

    for (k = 0; k < nr_of_sfb; k++) {

      sfb_offset[index] = sfb_offset[index - 1] + sfb_width_table[k] * window_group_length[i];

      index++;

    }

  }

  return;

}

static VOID iusace_degroup_int(const WORD32 *ptr_grouped_sfb_offsets, WORD32 sfb_per_group,

                               WORD32 *ptr_scratch, WORD32 *ptr_spec, WORD32 num_window_groups,

                               const WORD32 *window_group_length, WORD32 ccfl)

{

  WORD32 i, j, k, n;

  WORD32 index, group_offset;

  WORD32 loop1, loop2;

  WORD32 frame_len_short = (ccfl * FRAME_LEN_SHORT_128) / FRAME_LEN_LONG;

  index = 0;

  group_offset = 0;

  memset(ptr_scratch, 0, ccfl * sizeof(WORD32));

  for (i = 0; i < num_window_groups; i++) {

    for (j = 0; j < sfb_per_group; j++) {

      WORD32 idx = i * sfb_per_group + j;

      loop1 = ((ptr_grouped_sfb_offsets[idx + 1] - ptr_grouped_sfb_offsets[idx]) /

               window_group_length[i]);

      for (k = 0; k < window_group_length[i]; k++) {

        loop2 = ((ptr_grouped_sfb_offsets[idx] - group_offset) / window_group_length[i]) +

                frame_len_short * k + group_offset;

        for (n = 0; n < loop1; n++) {

          ptr_scratch[n + loop2] = ptr_spec[index++];

        }

      }

    }

    group_offset += frame_len_short * window_group_length[i];

  }

  memcpy(ptr_spec, ptr_scratch, ccfl * sizeof(WORD32));

  return;

}

IA_ERRORCODE iusace_stereo_proc(ia_sfb_params_struct *pstr_sfb_prms,

                                WORD32 usac_independancy_flag, ia_usac_data_struct *ptr_usac_data,

                                ia_usac_encoder_config_struct *ptr_usac_config, WORD32 chn) {

  IA_ERRORCODE err_code;

  WORD32 i = 0;

  WORD32 j = 0;

  iusace_scratch_mem *pstr_scratch = &ptr_usac_data->str_scratch;

  ia_psy_mod_data_struct *pstr_psy_data = ptr_usac_data->str_psy_mod.str_psy_data;

  ia_psy_mod_out_data_struct *pstr_psy_out = ptr_usac_data->str_psy_mod.str_psy_out_data;

  WORD32 *ptr_num_sfb = pstr_sfb_prms->num_sfb;

  WORD32 *ptr_num_window_groups = pstr_sfb_prms->num_window_groups;

  WORD32 ccfl = ptr_usac_config->ccfl;

  ia_ms_info_struct *pstr_ms_info = &ptr_usac_data->str_ms_info[chn];

  FLOAT64 tmp = 0.0f;

  FLOAT32 nrg_mid = 0.0f, nrg_side = 0.0f, nrg_left = 0.0f, nrg_right = 0.0f;

  FLOAT64 *ptr_scratch_spec = pstr_scratch->p_quant_spectrum_spec_scratch;

  FLOAT32 ratio_mid = 0.0f, ratio_side = 0.0f;

  FLOAT32 eps = 1.0e-6f;

  /* Save a copy of left and right channel MDCT spectra before they are modified */

  memcpy(ptr_usac_data->left_chan_save[chn], ptr_usac_data->spectral_line_vector[chn],

         ccfl * sizeof(FLOAT64));

  memcpy(ptr_usac_data->right_chan_save[chn], ptr_usac_data->spectral_line_vector[chn + 1],

         ccfl * sizeof(FLOAT64));

  if (ptr_usac_config->cmplx_pred_flag == 1) {

    /* Refinement - decision on whether to use complex prediction or MS */

    for (i = 0; i < ccfl; i++) {

      tmp = ptr_usac_data->spectral_line_vector[chn][i];

      ptr_scratch_spec[i] = 0.5f * (ptr_usac_data->spectral_line_vector[chn][i] +

                                    ptr_usac_data->spectral_line_vector[chn + 1][i]);

      ptr_scratch_spec[ccfl + i] = 0.5f * (tmp - ptr_usac_data->spectral_line_vector[chn + 1][i]);

    }

    for (i = 0; i < ccfl; i++) {

      nrg_mid += (FLOAT32)(ptr_scratch_spec[i] * ptr_scratch_spec[i]);

      nrg_side += (FLOAT32)(ptr_scratch_spec[ccfl + i] * ptr_scratch_spec[ccfl + i]);

      nrg_left += (FLOAT32)(ptr_usac_data->spectral_line_vector[chn][i] *

                            ptr_usac_data->spectral_line_vector[chn][i]);

      nrg_right += (FLOAT32)(ptr_usac_data->spectral_line_vector[chn + 1][i] *

                             ptr_usac_data->spectral_line_vector[chn + 1][i]);

    }

    ratio_mid = nrg_mid / (MAX(nrg_left, nrg_right) + eps);

    ratio_side = nrg_side / (MAX(nrg_left, nrg_right) + eps);

    if (ratio_mid >= 0.8f || ratio_side >= 0.8f || nrg_mid == 0.f || nrg_side == 0.f) {

      pstr_ms_info->ms_mask = 0;

    } else {

      pstr_ms_info->ms_mask = 3;

    }

  }

  if (pstr_ms_info->ms_mask != 3) {

    WORD32 idx = 0;

    WORD32 sfb;

    for (sfb = 0; sfb < ptr_num_sfb[chn]; sfb++) {

      ptr_usac_data->pred_coef_re_prev[chn][sfb] = 0;

      ptr_usac_data->pred_coef_im_prev[chn][sfb] = 0;

      ptr_usac_data->temp_pred_coef_re_prev[chn][sfb] = 0;

      ptr_usac_data->temp_pred_coef_im_prev[chn][sfb] = 0;

    }

    memset(ptr_usac_data->str_ms_info[chn].ms_used, 0,

           MAX_SFB_LONG * MAX_SHORT_WINDOWS * sizeof(WORD32));

    iusace_ms_apply(pstr_psy_data, ptr_usac_data->spectral_line_vector[chn],

                    ptr_usac_data->spectral_line_vector[chn + 1],

                    &ptr_usac_data->str_ms_info[chn].ms_mask,

                    ptr_usac_data->str_ms_info[chn].ms_used,

                    ptr_num_window_groups[chn] * ptr_num_sfb[chn], ptr_num_sfb[chn],

                    pstr_psy_out[chn].max_sfb_per_grp, pstr_sfb_prms->grouped_sfb_offset[chn],

                    chn, ptr_usac_config->cmplx_pred_flag == 1 ? ptr_scratch_spec : NULL);

    for (i = 0; i < ptr_num_window_groups[chn]; i++) {

      for (j = 0; j < ptr_num_sfb[chn]; j++) {

        pstr_psy_out[chn].ms_used[idx++] = ptr_usac_data->str_ms_info[chn].ms_used[i][j];

      }

    }

  } else {

    /* Reset buffer to zero */

    for (WORD32 group = 0; group < MAX_SHORT_WINDOWS; group++) {

      memset(ptr_usac_data->cplx_pred_used[chn][group], 0, MAX_SFB_LONG * sizeof(WORD32));

    }

    ptr_usac_data->cplx_pred_all[chn] = 1; /* Disable bandwise switching to L/R */

    for (i = 0; i < ptr_num_window_groups[chn]; i++) {

      for (j = 0; j < ptr_num_sfb[chn]; j += 2) {

        ptr_usac_data->cplx_pred_used[chn][i][j] = 1;

        if ((j + 1) < ptr_num_sfb[chn]) {

          ptr_usac_data->cplx_pred_used[chn][i][j + 1] = ptr_usac_data->cplx_pred_used[chn][i][j];

        }

      }

    }

    err_code = iusace_cplx_pred_proc(

        ptr_usac_data, ptr_usac_config, usac_independancy_flag, pstr_sfb_prms, chn, pstr_psy_data,

        pstr_sfb_prms->grouped_sfb_offset[chn], pstr_scratch->p_cmpx_mdct_temp_buf,

        ptr_scratch_spec, nrg_mid, nrg_side);

    if (err_code != IA_NO_ERROR) {

      return err_code;

    }

  }

  return IA_NO_ERROR;

}

IA_ERRORCODE iusace_grouping(ia_sfb_params_struct *pstr_sfb_prms, WORD32 num_chans,

                             ia_usac_data_struct *ptr_usac_data,

                             ia_usac_encoder_config_struct *ptr_usac_config, WORD32 chn,

                             WORD32 ele_id) {

  WORD32 i = 0, grp, sfb, wnd;

  WORD32 j = 0;

  WORD32 k;

  WORD32 ch;

  ia_psy_mod_struct *pstr_psy_config = &ptr_usac_data->str_psy_mod;

  ia_psy_mod_data_struct *pstr_psy_data = ptr_usac_data->str_psy_mod.str_psy_data;

  WORD32 *ptr_window_sequence = pstr_sfb_prms->window_sequence;

  WORD32 *ptr_num_sfb = pstr_sfb_prms->num_sfb;

  WORD32 *ptr_num_window_groups = pstr_sfb_prms->num_window_groups;

  ia_psy_mod_out_data_struct *pstr_psy_out = ptr_usac_data->str_psy_mod.str_psy_out_data;

  for (ch = chn; ch < chn + num_chans; ch++) {

    if (ptr_window_sequence[ch] == EIGHT_SHORT_SEQUENCE) {

      iusace_sort_for_grouping(

          pstr_sfb_prms->grouped_sfb_offset[ch], pstr_sfb_prms->sfb_width_table[ch],

          ptr_usac_data->str_scratch.p_sort_grouping_scratch,

          ptr_usac_data->spectral_line_vector[ch], ptr_num_window_groups[ch],

          pstr_sfb_prms->window_group_length[ch], ptr_num_sfb[ch], ptr_usac_config->ccfl);

    } else if ((ptr_window_sequence[ch] == ONLY_LONG_SEQUENCE) ||

               (ptr_window_sequence[ch] == LONG_START_SEQUENCE) ||

               (ptr_window_sequence[ch] == LONG_STOP_SEQUENCE) ||

               (ptr_window_sequence[ch] == STOP_START_SEQUENCE)) {

      pstr_sfb_prms->grouped_sfb_offset[ch][0] = 0;

      k = 0;

      for (i = 0; i < ptr_num_sfb[ch]; i++) {

        pstr_sfb_prms->grouped_sfb_offset[ch][i] = k;

        k += pstr_sfb_prms->sfb_width_table[ch][i];

      }

      pstr_sfb_prms->grouped_sfb_offset[ch][i] = k;

    } else {

      return IA_EXHEAACE_EXE_FATAL_USAC_INVALID_WINDOW_TYPE;

    }

  }

  for (ch = chn; ch < chn + num_chans; ch++) {

    if (pstr_psy_data[ch].window_sequence == 2) {

      i = 0;

      for (grp = 0; grp < ptr_num_window_groups[ch]; grp++) {

        for (sfb = 0; sfb < ptr_num_sfb[ch]; sfb++) {

          pstr_psy_out[ch].sfb_min_snr[i++] =

              pstr_psy_config->str_psy_short_config[ele_id].sfb_min_snr[sfb];

        }

      }

      wnd = 0;

      i = 0;

      for (grp = 0; grp < ptr_num_window_groups[ch]; grp++) {

        for (sfb = 0; sfb < ptr_num_sfb[ch]; sfb++) {

          FLOAT32 threshold = pstr_psy_data[ch].sfb_thr_short[wnd][sfb];

          FLOAT32 energy = pstr_psy_data[ch].sfb_energy_short[wnd][sfb];

          FLOAT32 energy_ms = pstr_psy_data[ch].ptr_sfb_energy_short_ms[wnd][sfb];

          FLOAT32 spread_energy = pstr_psy_data[ch].sfb_spreaded_energy_short[wnd][sfb];

          for (j = 1; j < pstr_sfb_prms->window_group_length[ch][grp]; j++) {

            threshold = threshold + pstr_psy_data[ch].sfb_thr_short[wnd + j][sfb];

            energy = energy + pstr_psy_data[ch].sfb_energy_short[wnd + j][sfb];

            spread_energy =

                spread_energy + pstr_psy_data[ch].sfb_spreaded_energy_short[wnd + j][sfb];

            energy_ms = energy_ms + pstr_psy_data[ch].ptr_sfb_energy_short_ms[wnd + j][sfb];

          }

          pstr_psy_data[ch].ptr_sfb_thr_long[i] = threshold;

          pstr_psy_data[ch].ptr_sfb_energy_long[i] = energy;

          pstr_psy_data[ch].ptr_sfb_energy_long_ms[i] = energy_ms;

          pstr_psy_data[ch].ptr_sfb_spreaded_energy_long[i++] = spread_energy;

        }

        wnd += pstr_sfb_prms->window_group_length[ch][grp];

      }

    } else {

      for (sfb = 0; sfb < ptr_num_sfb[ch]; sfb++) {

        pstr_psy_out[ch].sfb_min_snr[sfb] =

            pstr_psy_config->str_psy_long_config[ele_id].sfb_min_snr[sfb];

      }

    }

  }

  return IA_NO_ERROR;

}

IA_ERRORCODE iusace_quantize_spec(ia_sfb_params_struct *pstr_sfb_prms,

                                  WORD32 usac_independancy_flag, WORD32 num_chans,

                                  ia_usac_data_struct *ptr_usac_data,

                                  ia_usac_encoder_config_struct *ptr_usac_config, WORD32 chn,

                                  WORD32 ele_id, WORD32 *is_quant_spec_zero,

                                  WORD32 *is_gain_limited) {

  IA_ERRORCODE err_code;

  WORD32 i = 0, sfb;

  WORD32 j = 0;

  WORD32 k;

  WORD32 max_bits;

  WORD32 ch;

  iusace_scratch_mem *pstr_scratch = &ptr_usac_data->str_scratch;

  WORD32 num_scfs[2];

  FLOAT32 **sfb_form_fac = &pstr_scratch->ptr_sfb_form_fac[0];

  WORD32 max_ch_dyn_bits[2] = {0};

  FLOAT32 ch_bit_dist[2];

  WORD32 constraints_fulfilled;

  WORD32 iterations = 0;

  WORD32 max_val;

  WORD32 kk, idx = 0;

  FLOAT32 *ptr_exp_spec = pstr_scratch->p_exp_spec;

  FLOAT32 *ptr_mdct_spec_float = pstr_scratch->p_mdct_spec_float;

  ia_psy_mod_data_struct *pstr_psy_data = ptr_usac_data->str_psy_mod.str_psy_data;

  ia_qc_out_data_struct *pstr_qc_out = &ptr_usac_data->str_qc_main.str_qc_out;

  ia_psy_mod_out_data_struct *pstr_psy_out = ptr_usac_data->str_psy_mod.str_psy_out_data;

  ia_qc_data_struct *pstr_qc_data = &ptr_usac_data->str_qc_main.str_qc_data[ele_id];

  ia_adj_thr_elem_struct *pstr_adj_thr_elem = &pstr_qc_data->str_adj_thr_ele;

  WORD32 *ptr_window_sequence = pstr_sfb_prms->window_sequence;

  WORD32 *ptr_max_sfb = pstr_sfb_prms->max_sfb;

  WORD32 *ptr_num_sfb = pstr_sfb_prms->num_sfb;

  WORD32 *ptr_num_window_groups = pstr_sfb_prms->num_window_groups;

  WORD32 bitres_bits, bitres_diff;

  WORD32 gain;

  memset(num_scfs, 0, 2 * sizeof(num_scfs[0]));

  for (ch = chn; ch < chn + num_chans; ch++) {

    num_scfs[idx] = ptr_num_sfb[ch] * ptr_num_window_groups[ch];

    pstr_psy_out[ch].sfb_count = num_scfs[idx];

    pstr_psy_out[ch].sfb_per_group = num_scfs[idx] / ptr_num_window_groups[ch];

    pstr_psy_out[ch].window_sequence = pstr_psy_data[ch].window_sequence;

    pstr_psy_out[ch].window_shape = iusace_window_shape[pstr_psy_data[ch].window_sequence];

    pstr_psy_out[ch].ptr_spec_coeffs = ptr_usac_data->spectral_line_vector[ch];

    pstr_psy_out[ch].ptr_sfb_energy = pstr_psy_data[ch].ptr_sfb_energy_long;

    pstr_psy_out[ch].ptr_sfb_thr = pstr_psy_data[ch].ptr_sfb_thr_long;

    pstr_psy_out[ch].ptr_sfb_spread_energy = pstr_psy_data[ch].ptr_sfb_spreaded_energy_long;

    for (j = 0; j < num_scfs[idx]; j++) {

      pstr_psy_out[ch].sfb_offsets[j] = pstr_sfb_prms->grouped_sfb_offset[ch][j];

    }

    pstr_psy_out[ch].sfb_offsets[num_scfs[idx]] =

        pstr_sfb_prms->grouped_sfb_offset[ch][num_scfs[idx]];

    for (j = 0; j < MAX_NUM_GROUPED_SFB; j++) {

      sfb_form_fac[idx][j] = MIN_FLT_VAL;

    }

    iusace_calc_form_fac_per_chan(&pstr_psy_out[ch], pstr_scratch, idx);

    idx++;

  }

  pstr_qc_out->static_bits =

      iusace_count_static_bits(ptr_usac_data, ptr_usac_config, pstr_sfb_prms, pstr_psy_out,

                               num_chans, chn, usac_independancy_flag, ele_id);

  iusace_adj_bitrate(pstr_qc_data, pstr_qc_data->ch_bitrate, ptr_usac_config->core_sample_rate,

                     ptr_usac_config->ccfl);

  err_code =

      iusace_adj_thr(pstr_adj_thr_elem, pstr_psy_out, ch_bit_dist, pstr_qc_out,

                     pstr_qc_data->avg_bits - pstr_qc_out->static_bits, pstr_qc_data->bit_res_lvl,

                     pstr_qc_data->max_bitres_bits, pstr_qc_out->static_bits,

                     &pstr_qc_data->max_bit_fac, num_chans, chn, pstr_scratch);

  if (err_code != IA_NO_ERROR) {

    return err_code;

  }

  iusace_estimate_scfs_chan(pstr_psy_out, pstr_qc_out->str_qc_out_chan, num_chans, chn,

                            pstr_scratch);

  idx = 0;

  for (ch = 0; ch < num_chans; ch++) {

    max_ch_dyn_bits[ch] = (WORD32)floor(

        ch_bit_dist[ch] * (FLOAT32)(pstr_qc_data->avg_bits + pstr_qc_data->bit_res_lvl - 7 -

                                    pstr_qc_out->static_bits));

    idx++;

  }

  pstr_qc_out->dyn_bits = 0;

  idx = 0;

  for (ch = chn; ch < chn + num_chans; ch++) {

    iterations = 0;

    gain = 0;

    for (kk = 0; kk < ptr_usac_config->ccfl; kk++) {

      ptr_exp_spec[kk] = (FLOAT32)pstr_psy_out[ch].ptr_spec_coeffs[kk];

      ptr_mdct_spec_float[kk] = (FLOAT32)pstr_psy_out[ch].ptr_spec_coeffs[kk];

    }

    do {

      constraints_fulfilled = 1;

      WORD32 quant_spec_is_zero = 1;

      if (iterations > 0) {

        for (WORD32 sfb_offs = 0; sfb_offs < pstr_psy_out[ch].sfb_count;

             sfb_offs += pstr_psy_out[ch].sfb_per_group) {

          for (sfb = 0; sfb < pstr_psy_out[ch].max_sfb_per_grp; sfb++) {

            WORD32 scalefactor = pstr_qc_out->str_qc_out_chan[idx].scalefactor[sfb + sfb_offs];

            gain = MAX(gain, pstr_qc_out->str_qc_out_chan[idx].global_gain - scalefactor);

            iusace_quantize_lines(

                pstr_qc_out->str_qc_out_chan[idx].global_gain - scalefactor,

                pstr_psy_out[ch].sfb_offsets[sfb_offs + sfb + 1] -

                    pstr_psy_out[ch].sfb_offsets[sfb_offs + sfb],

                ptr_exp_spec + pstr_psy_out[ch].sfb_offsets[sfb_offs + sfb],

                pstr_qc_out->str_qc_out_chan[idx].quant_spec +

                    pstr_psy_out[ch].sfb_offsets[sfb_offs + sfb],

                ptr_mdct_spec_float + pstr_psy_out[ch].sfb_offsets[sfb_offs + sfb]);

          }

        }

      }

      max_val =

          iusace_calc_max_val_in_sfb(pstr_psy_out[ch].sfb_count, pstr_psy_out[ch].max_sfb_per_grp,

                                     pstr_psy_out[ch].sfb_per_group, pstr_psy_out[ch].sfb_offsets,

                                     pstr_qc_out->str_qc_out_chan[idx].quant_spec);

      if (max_val > MAX_QUANT) {

        constraints_fulfilled = 0;

      }

      for (k = 0; k < num_scfs[idx]; k++) {

        for (i = pstr_sfb_prms->grouped_sfb_offset[ch][k];

             i < pstr_sfb_prms->grouped_sfb_offset[ch][k + 1]; i++) {

          ptr_usac_data->str_quant_info[idx].quant_degroup[i] =

              (WORD32)pstr_qc_out->str_qc_out_chan[idx].quant_spec[i];

          if (ptr_usac_data->str_quant_info[idx].quant_degroup[i] != 0) {

            quant_spec_is_zero = 0;

          }

        }

      }

      if (ptr_window_sequence[ch] == EIGHT_SHORT_SEQUENCE) {

        iusace_degroup_int(pstr_sfb_prms->grouped_sfb_offset[ch], ptr_num_sfb[ch],

                           ptr_usac_data->str_scratch.p_degroup_scratch,

                           ptr_usac_data->str_quant_info[idx].quant_degroup,

                           ptr_num_window_groups[ch], pstr_sfb_prms->window_group_length[ch],

                           ptr_usac_config->ccfl);

      }

      ptr_usac_data->str_quant_info[idx].max_spec_coeffs = 0;

      for (k = 0; k < ptr_max_sfb[ch]; k++) {

        ptr_usac_data->str_quant_info[idx].max_spec_coeffs +=

            pstr_sfb_prms->sfb_width_table[ch][k];

      }

      for (i = 0; i < num_scfs[idx]; i++) {

        ptr_usac_data->str_quant_info[idx].scale_factor[i] =

            pstr_qc_out->str_qc_out_chan[idx].global_gain -

            pstr_qc_out->str_qc_out_chan[idx].scalefactor[i] + SF_OFFSET;

      }

      max_bits = iusace_count_fd_bits(pstr_sfb_prms, ptr_usac_data, usac_independancy_flag,

                                      ptr_usac_config, ch, idx);

      if (max_bits > max_ch_dyn_bits[idx]) {

        constraints_fulfilled = 0;

      }

      if (quant_spec_is_zero == 1) {

        constraints_fulfilled = 1;

        /*Bit consuption is exceding bit reservoir, there is no scope left for bit consumption

          reduction, as spectrum is zero. Hence breaking the quantization loop. */

        if (iterations > 0) {

          *is_quant_spec_zero = 1;

          max_bits = max_ch_dyn_bits[idx];

        }

      }

      if ((gain == MAX_GAIN_INDEX) && (constraints_fulfilled == 0)) {

        /* Bit consuption is exceding bit reservoir, there is no scope left for bit consumption

           reduction, as gain has reached the maximum value. Hence breaking the quantization

           loop. */

        constraints_fulfilled = 1;

        *is_gain_limited = 1;

        max_bits = max_ch_dyn_bits[idx];

      }

      if (!constraints_fulfilled) {

        pstr_qc_out->str_qc_out_chan[idx].global_gain++;

      }

      iterations++;

    } while (!constraints_fulfilled);

    pstr_qc_out->dyn_bits += max_bits;

    if (ptr_usac_data->noise_filling[ele_id]) {

      WORD32 max_nf_sfb = ptr_max_sfb[ch];

      if (ptr_window_sequence[ch] != EIGHT_SHORT_SEQUENCE) {

        iusace_noise_filling(

            &ptr_usac_data->noise_level[idx], &ptr_usac_data->noise_offset[idx],

            ptr_usac_data->spectral_line_vector[ch], &ptr_usac_data->str_quant_info[idx],

            pstr_sfb_prms->grouped_sfb_offset[ch], max_nf_sfb, ptr_usac_config->ccfl,

            ptr_num_window_groups[ch], pstr_sfb_prms->window_group_length[ch], 160,

            ptr_usac_data->str_scratch.p_noise_filling_highest_tone);

      } else {

        iusace_noise_filling(

            &ptr_usac_data->noise_level[idx], &ptr_usac_data->noise_offset[idx],

            ptr_usac_data->spectral_line_vector[ch], &ptr_usac_data->str_quant_info[idx],

            pstr_sfb_prms->grouped_sfb_offset[ch], max_nf_sfb, ptr_usac_config->ccfl >> 3,

            ptr_num_window_groups[ch], pstr_sfb_prms->window_group_length[ch], 20,

            (FLOAT64 *)ptr_usac_data->str_scratch.p_noise_filling_highest_tone);

      }

      if (ptr_usac_data->noise_level[idx] == 0 && ptr_usac_data->noise_offset[idx] != 0 &&

          pstr_sfb_prms->common_win[ch]) {

        ptr_usac_data->complex_coef[ch] = 0;

      }

    }

    idx++;

  }

  pstr_adj_thr_elem->dyn_bits_last = pstr_qc_out->dyn_bits;

  bitres_bits = pstr_qc_data->max_bitres_bits - pstr_qc_data->bit_res_lvl;

  bitres_diff = pstr_qc_data->avg_bits - (pstr_qc_out->static_bits + pstr_qc_out->dyn_bits);

  pstr_qc_out->fill_bits = MAX(0, (bitres_diff - bitres_bits));

  if (pstr_qc_data->avg_bits > 0) {

    pstr_qc_data->bit_res_lvl +=

        pstr_qc_data->avg_bits -

        (pstr_qc_out->static_bits + pstr_qc_out->dyn_bits + pstr_qc_out->fill_bits);

  } else {

    pstr_qc_data->bit_res_lvl = pstr_qc_data->max_bits;

  }

  if (pstr_qc_data->bit_res_lvl < 0 ||

      pstr_qc_data->bit_res_lvl > pstr_qc_data->max_bitres_bits) {

    return IA_EXHEAACE_EXE_FATAL_USAC_INVALID_BIT_RSVR_LVL;

  }

  return IA_NO_ERROR;

}