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      1 /******************************************************************************
      2  *                                                                            *
      3  * Copyright (C) 2018 The Android Open Source Project
      4  *
      5  * Licensed under the Apache License, Version 2.0 (the "License");
      6  * you may not use this file except in compliance with the License.
      7  * You may obtain a copy of the License at:
      8  *
      9  * http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  * Unless required by applicable law or agreed to in writing, software
     12  * distributed under the License is distributed on an "AS IS" BASIS,
     13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  * See the License for the specific language governing permissions and
     15  * limitations under the License.
     16  *
     17  *****************************************************************************
     18  * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
     19  */
     20 
     21 #include <stdlib.h>
     22 #include <stdio.h>
     23 #include <string.h>
     24 
     25 #include <ixheaacd_type_def.h>
     26 #include "ixheaacd_constants.h"
     27 #include <ixheaacd_basic_ops32.h>
     28 #include <ixheaacd_basic_ops16.h>
     29 #include <ixheaacd_basic_ops40.h>
     30 
     31 #include "ixheaacd_defines.h"
     32 #include <ixheaacd_aac_rom.h>
     33 #include "ixheaacd_audioobjtypes.h"
     34 
     35 #include "ixheaacd_bitbuffer.h"
     36 #include "ixheaacd_pulsedata.h"
     37 #include "ixheaacd_pns.h"
     38 #include "ixheaacd_lt_predict.h"
     39 #include "ixheaacd_channelinfo.h"
     40 #include "ixheaacd_cnst.h"
     41 #include "ixheaacd_tns.h"
     42 #include "ixheaacd_aac_imdct.h"
     43 
     44 static const WORD32 ixheaacd_codebook_Q30[8] = {
     45     612922971,  747985734,  872956397,  978505219,
     46     1057528322, 1146642451, 1282693056, 1470524861};
     47 
     48 #define SHIFT_VAL 8
     49 #define SHIFT_VAL1 (15 - SHIFT_VAL)
     50 
     51 VOID ixheaacd_lt_prediction(
     52     ia_aac_dec_channel_info_struct *ptr_aac_dec_channel_info, ltp_info *ltp,
     53     WORD32 *spec, ia_aac_dec_tables_struct *aac_tables_ptr,
     54     UWORD16 win_shape_prev, UWORD32 sr_index, UWORD32 object_type,
     55     UWORD32 frame_len, WORD32 *in_data, WORD32 *out_data) {
     56   ia_ics_info_struct *ptr_ics_info = &ptr_aac_dec_channel_info->str_ics_info;
     57   WORD16 *lt_pred_stat = ptr_aac_dec_channel_info->ltp_buf;
     58   UWORD16 win_shape = ptr_aac_dec_channel_info->str_ics_info.window_shape;
     59   WORD16 sfb;
     60   WORD16 bin, i, num_samples;
     61   const WORD8 *swb_offset = aac_tables_ptr->scale_factor_bands_long[sr_index];
     62   WORD32 *ptr_spec = &spec[0];
     63   WORD32 *ptr_x_est = &out_data[0];
     64 
     65   if (512 == ptr_ics_info->frame_length) {
     66     swb_offset = aac_tables_ptr->scale_fac_bands_512[sr_index];
     67   } else if (480 == ptr_ics_info->frame_length) {
     68     swb_offset = aac_tables_ptr->scale_fac_bands_480[sr_index];
     69   }
     70 
     71   if (ptr_ics_info->window_sequence != EIGHT_SHORT_SEQUENCE) {
     72     if (ltp->data_present) {
     73       num_samples = frame_len << 1;
     74 
     75       for (i = 0; i < num_samples; i++) {
     76         in_data[i] =
     77             ixheaacd_shr32(ixheaacd_mult32x16in32_shl(
     78                                ixheaacd_codebook_Q30[ltp->coef],
     79                                lt_pred_stat[num_samples + i - ltp->lag]),
     80                            SHIFT_VAL);
     81       }
     82 
     83       ixheaacd_filter_bank_ltp(aac_tables_ptr, ptr_ics_info->window_sequence,
     84                                win_shape, win_shape_prev, in_data, out_data,
     85                                object_type, frame_len);
     86 
     87       if (ptr_aac_dec_channel_info->str_tns_info.tns_data_present == 1)
     88         ixheaacd_aac_tns_process(ptr_aac_dec_channel_info, 1, aac_tables_ptr,
     89                                  object_type, 0, out_data);
     90 
     91       for (sfb = 0; sfb < ltp->last_band; sfb++) {
     92         WORD8 sfb_width = swb_offset[sfb];
     93         if (ltp->long_used[sfb]) {
     94           for (bin = sfb_width - 1; bin >= 0; bin--) {
     95             WORD32 temp = *ptr_spec;
     96             temp += ixheaacd_shr32(*ptr_x_est++, SHIFT_VAL1);
     97 
     98             *ptr_spec++ = temp;
     99           }
    100         } else {
    101           ptr_spec += sfb_width;
    102           ptr_x_est += sfb_width;
    103         }
    104       }
    105     }
    106   }
    107 }
    108 
    109 VOID ixheaacd_filter_bank_ltp(ia_aac_dec_tables_struct *aac_tables_ptr,
    110                               WORD16 window_sequence, WORD16 window_shape,
    111                               WORD16 window_shape_prev, WORD32 *in_data,
    112                               WORD32 *out_mdct, UWORD32 object_type,
    113                               UWORD32 frame_len) {
    114   WORD32 i;
    115 
    116   const WORD16 *window_long = NULL;
    117   const WORD16 *window_long_prev = NULL;
    118   const WORD16 *window_short = NULL;
    119   const WORD16 *window_short_prev = NULL;
    120 
    121   UWORD16 nlong = frame_len;
    122   UWORD16 nlong2 = frame_len << 1;
    123   UWORD16 nshort = frame_len / 8;
    124   UWORD16 nflat_ls = (nlong - nshort) / 2;
    125   WORD32 imdct_scale = 0;
    126   WORD32 expo = 0;
    127 
    128   if (object_type == AOT_ER_AAC_LD) {
    129     if (!window_shape) {
    130       if (512 == frame_len) {
    131         window_long =
    132             (WORD16 *)aac_tables_ptr->pstr_imdct_tables->window_sine_512;
    133       } else {
    134         window_long =
    135             (WORD16 *)aac_tables_ptr->pstr_imdct_tables->window_sine_480;
    136       }
    137     } else {
    138       if (512 == frame_len) {
    139         window_long =
    140             (WORD16 *)aac_tables_ptr->pstr_imdct_tables->low_overlap_win;
    141       } else {
    142         window_long =
    143             (WORD16 *)aac_tables_ptr->pstr_imdct_tables->low_overlap_win_480;
    144       }
    145     }
    146 
    147     if (!window_shape_prev) {
    148       if (512 == frame_len) {
    149         window_long_prev =
    150             (WORD16 *)aac_tables_ptr->pstr_imdct_tables->window_sine_512;
    151       } else {
    152         window_long_prev =
    153             (WORD16 *)aac_tables_ptr->pstr_imdct_tables->window_sine_480;
    154       }
    155     } else {
    156       if (512 == frame_len) {
    157         window_long_prev =
    158             (WORD16 *)aac_tables_ptr->pstr_imdct_tables->low_overlap_win;
    159       } else {
    160         window_long_prev =
    161             (WORD16 *)aac_tables_ptr->pstr_imdct_tables->low_overlap_win_480;
    162       }
    163     }
    164 
    165     if (!window_shape)
    166       window_short = aac_tables_ptr->pstr_imdct_tables->only_short_window_sine;
    167     else
    168       window_short = aac_tables_ptr->pstr_imdct_tables->only_short_window_kbd;
    169     if (!window_shape_prev)
    170       window_short_prev =
    171           aac_tables_ptr->pstr_imdct_tables->only_short_window_sine;
    172     else
    173       window_short_prev =
    174           aac_tables_ptr->pstr_imdct_tables->only_short_window_kbd;
    175 
    176   } else {
    177     if (!window_shape)
    178       window_long = aac_tables_ptr->pstr_imdct_tables->only_long_window_sine;
    179     else
    180       window_long = aac_tables_ptr->pstr_imdct_tables->only_long_window_kbd;
    181     if (!window_shape_prev)
    182       window_long_prev =
    183           aac_tables_ptr->pstr_imdct_tables->only_long_window_sine;
    184     else
    185       window_long_prev =
    186           aac_tables_ptr->pstr_imdct_tables->only_long_window_kbd;
    187 
    188     if (!window_shape)
    189       window_short = aac_tables_ptr->pstr_imdct_tables->only_short_window_sine;
    190     else
    191       window_short = aac_tables_ptr->pstr_imdct_tables->only_short_window_kbd;
    192     if (!window_shape_prev)
    193       window_short_prev =
    194           aac_tables_ptr->pstr_imdct_tables->only_short_window_sine;
    195     else
    196       window_short_prev =
    197           aac_tables_ptr->pstr_imdct_tables->only_short_window_kbd;
    198   }
    199 
    200   switch (window_sequence) {
    201     case ONLY_LONG_SEQUENCE:
    202 
    203       if ((512 != nlong) && (480 != nlong)) {
    204         for (i = 0; i<nlong>> 1; i++) {
    205           in_data[i] =
    206               ixheaacd_mult32x16in32_shl(in_data[i], window_long_prev[2 * i]);
    207 
    208           in_data[i + nlong] = ixheaacd_mult32x16in32_shl(
    209               in_data[i + nlong], window_long[2 * i + 1]);
    210         }
    211         for (i = 0; i<nlong>> 1; i++) {
    212           in_data[i + (nlong >> 1)] = ixheaacd_mult32x16in32_shl(
    213               in_data[i + (nlong >> 1)], window_long_prev[nlong - 1 - 2 * i]);
    214 
    215           in_data[i + nlong + (nlong >> 1)] =
    216               ixheaacd_mult32x16in32_shl(in_data[i + nlong + (nlong >> 1)],
    217                                          window_long[nlong - 1 - 2 * i - 1]);
    218         }
    219 
    220       } else {
    221         WORD32 *win1, *win2, *win3;
    222         WORD32 *ptr_in1, *ptr_in2;
    223         win1 = (WORD32 *)window_long_prev;
    224         win2 = (WORD32 *)window_long;
    225         ptr_in1 = &in_data[0];
    226         ptr_in2 = &in_data[nlong];
    227         win3 = win2 + nlong - 1;
    228 
    229         for (i = nlong - 1; i >= 0; i--) {
    230           WORD32 temp1 = ixheaacd_mult32_shl(*ptr_in1, *win1++);
    231           WORD32 temp2 = ixheaacd_mult32_shl(*ptr_in2, win2[i]);
    232 
    233           *ptr_in1++ = temp1;
    234           *ptr_in2++ = temp2;
    235         }
    236       }
    237 
    238       for (i = 0; i < nlong / 2; i++) {
    239         out_mdct[nlong / 2 + i] =
    240             ixheaacd_sub32(in_data[i], in_data[nlong - 1 - i]);
    241         out_mdct[i] = (-ixheaacd_add32(in_data[nlong + i + nlong / 2],
    242                                        in_data[nlong2 - nlong / 2 - 1 - i]));
    243       }
    244 
    245       if (512 == nlong || (480 == nlong)) {
    246         if (512 == nlong)
    247           ixheaacd_inverse_transform_512(
    248               out_mdct, in_data, &imdct_scale,
    249               aac_tables_ptr->pstr_imdct_tables->cosine_array_1024,
    250               aac_tables_ptr->pstr_imdct_tables, object_type);
    251 
    252         else
    253           ixheaacd_mdct_480_ld(out_mdct, in_data, &imdct_scale, 1,
    254                                aac_tables_ptr->pstr_imdct_tables, object_type);
    255 
    256         imdct_scale += 1;
    257 
    258         if (imdct_scale > 0) {
    259           WORD32 *ptr_out_mdct = &out_mdct[0];
    260 
    261           for (i = nlong - 1; i >= 0; i -= 4) {
    262             *ptr_out_mdct = ixheaacd_shl32(*ptr_out_mdct, imdct_scale);
    263             ptr_out_mdct++;
    264             *ptr_out_mdct = ixheaacd_shl32(*ptr_out_mdct, imdct_scale);
    265             ptr_out_mdct++;
    266             *ptr_out_mdct = ixheaacd_shl32(*ptr_out_mdct, imdct_scale);
    267             ptr_out_mdct++;
    268             *ptr_out_mdct = ixheaacd_shl32(*ptr_out_mdct, imdct_scale);
    269             ptr_out_mdct++;
    270           }
    271         } else if (imdct_scale < 0) {
    272           WORD32 *ptr_out_mdct = &out_mdct[0];
    273           imdct_scale = -imdct_scale;
    274           for (i = nlong - 1; i >= 0; i -= 4) {
    275             *ptr_out_mdct = ixheaacd_shr32(*ptr_out_mdct, imdct_scale);
    276             ptr_out_mdct++;
    277             *ptr_out_mdct = ixheaacd_shr32(*ptr_out_mdct, imdct_scale);
    278             ptr_out_mdct++;
    279             *ptr_out_mdct = ixheaacd_shr32(*ptr_out_mdct, imdct_scale);
    280             ptr_out_mdct++;
    281             *ptr_out_mdct = ixheaacd_shr32(*ptr_out_mdct, imdct_scale);
    282             ptr_out_mdct++;
    283           }
    284         }
    285       }
    286 
    287       else if (1024 == nlong) {
    288         expo = ixheaacd_calc_max_spectral_line_dec(out_mdct, 1024) - 1;
    289 
    290         expo = 8 - expo;
    291 
    292         imdct_scale = ixheaacd_inverse_transform(
    293             out_mdct, in_data, aac_tables_ptr->pstr_imdct_tables, expo, 1024);
    294 
    295         ixheaacd_post_twiddle_dec(in_data, out_mdct,
    296                                   aac_tables_ptr->pstr_imdct_tables, 1024);
    297 
    298         imdct_scale += 1;
    299 
    300         for (i = 0; i < nlong; i++) {
    301           out_mdct[i] = ixheaacd_shl32_dir(in_data[i], imdct_scale);
    302         }
    303       }
    304 
    305       break;
    306 
    307     case LONG_START_SEQUENCE:
    308 
    309       for (i = 0; i<nlong>> 1; i++)
    310         in_data[i] =
    311             ixheaacd_mult32x16in32_shl(in_data[i], window_long_prev[2 * i]);
    312 
    313       for (i = 0; i<nlong>> 1; i++)
    314         in_data[i + (nlong >> 1)] = ixheaacd_mult32x16in32_shl(
    315             in_data[i + (nlong >> 1)], window_long_prev[nlong - 1 - 2 * i - 1]);
    316 
    317       for (i = 0; i<nshort>> 1; i++)
    318         in_data[i + nlong + nflat_ls + (nshort >> 1)] =
    319             ixheaacd_mult32x16in32_shl(
    320                 in_data[i + nlong + nflat_ls + (nshort >> 1)],
    321                 window_short[nshort - 1 - 2 * i - 1]);
    322 
    323       for (i = 0; i < nflat_ls; i++) in_data[i + nlong + nflat_ls + nshort] = 0;
    324 
    325       for (i = 0; i < nlong / 2; i++) {
    326         out_mdct[nlong / 2 + i] =
    327             ixheaacd_sub32(in_data[i], in_data[nlong - 1 - i]);
    328         out_mdct[nlong / 2 - 1 - i] =
    329             -ixheaacd_add32(in_data[nlong + i], in_data[nlong2 - 1 - i]);
    330       }
    331 
    332       {
    333         expo = ixheaacd_calc_max_spectral_line_dec(out_mdct, 1024) - 1;
    334 
    335         expo = 8 - expo;
    336         imdct_scale = ixheaacd_inverse_transform(
    337             out_mdct, in_data, aac_tables_ptr->pstr_imdct_tables, expo, 1024);
    338 
    339         ixheaacd_post_twiddle_dec(in_data, out_mdct,
    340                                   aac_tables_ptr->pstr_imdct_tables, 1024);
    341       }
    342 
    343       imdct_scale += 1;
    344 
    345       for (i = 0; i < nlong; i++) {
    346         out_mdct[i] = ixheaacd_shl32_dir(in_data[i], imdct_scale);
    347       }
    348       break;
    349 
    350     case LONG_STOP_SEQUENCE:
    351       for (i = 0; i < nflat_ls; i++) in_data[i] = 0;
    352 
    353       for (i = 0; i<nshort>> 1; i++)
    354         in_data[i + nflat_ls] = ixheaacd_mult32x16in32_shl(
    355             in_data[i + nflat_ls], window_short_prev[2 * i]);
    356 
    357       for (i = 0; i<nshort>> 1; i++)
    358         in_data[i + nflat_ls + (nshort >> 1)] =
    359             ixheaacd_mult32x16in32_shl(in_data[i + nflat_ls + (nshort >> 1)],
    360                                        window_short_prev[127 - 2 * i]);
    361 
    362       for (i = 0; i<nlong>> 1; i++)
    363         in_data[i + nlong] = ixheaacd_mult32x16in32_shl(in_data[i + nlong],
    364                                                         window_long[2 * i + 1]);
    365 
    366       for (i = 0; i<nlong>> 1; i++)
    367         in_data[i + nlong + (nlong >> 1)] =
    368             ixheaacd_mult32x16in32_shl(in_data[i + nlong + (nlong >> 1)],
    369                                        window_long[nlong - 1 - 2 * i - 1]);
    370 
    371       for (i = 0; i < nlong / 2; i++) {
    372         out_mdct[nlong / 2 + i] =
    373             ixheaacd_sub32(in_data[i], in_data[nlong - 1 - i]);
    374         out_mdct[nlong / 2 - 1 - i] =
    375             -ixheaacd_add32(in_data[nlong + i], in_data[nlong2 - 1 - i]);
    376       }
    377 
    378       {
    379         expo = ixheaacd_calc_max_spectral_line_dec(out_mdct, 1024) - 1;
    380 
    381         expo = 8 - expo;
    382         imdct_scale = ixheaacd_inverse_transform(
    383             out_mdct, in_data, aac_tables_ptr->pstr_imdct_tables, expo, 1024);
    384 
    385         ixheaacd_post_twiddle_dec(in_data, out_mdct,
    386                                   aac_tables_ptr->pstr_imdct_tables, 1024);
    387       }
    388 
    389       imdct_scale += 1;
    390 
    391       for (i = 0; i < nlong; i++) {
    392         out_mdct[i] = ixheaacd_shl32_dir(in_data[i], imdct_scale);
    393       }
    394 
    395       break;
    396   }
    397 }
    398 
    399 VOID ixheaacd_lt_update_state(WORD16 *lt_pred_stat, WORD16 *time,
    400                               WORD32 *overlap, WORD32 frame_len,
    401                               WORD32 object_type, WORD32 stride,
    402                               WORD16 window_sequence, WORD16 *p_window_next) {
    403   WORD32 i;
    404   if (object_type == AOT_ER_AAC_LD) {
    405     WORD16 *ptr_ltp_state0 = &lt_pred_stat[0];
    406     WORD16 *ptr_ltp_state_fl = &lt_pred_stat[frame_len + 0];
    407     WORD16 *ptr_ltp_state_2fl = &lt_pred_stat[(frame_len * 2) + 0];
    408     WORD16 *ptr_time_in = &time[0 * stride];
    409 
    410     for (i = 0; i < frame_len; i++) {
    411       *ptr_ltp_state0++ = *ptr_ltp_state_fl;
    412       *ptr_ltp_state_fl++ = *ptr_ltp_state_2fl;
    413       *ptr_ltp_state_2fl++ = *ptr_time_in;
    414       ptr_time_in += stride;
    415     }
    416 
    417   } else {
    418     WORD16 *ptr_ltp_state0 = &lt_pred_stat[0];
    419     WORD16 *ptr_ltp_state_fl = &lt_pred_stat[frame_len + 0];
    420     WORD16 *ptr_time_in = &time[0 * stride];
    421 
    422     for (i = 0; i < frame_len; i++) {
    423       *ptr_ltp_state0++ = *ptr_ltp_state_fl;
    424       *ptr_ltp_state_fl++ = *ptr_time_in;
    425       ptr_time_in += stride;
    426     }
    427   }
    428 
    429   if ((window_sequence == ONLY_LONG_SEQUENCE) ||
    430       (window_sequence == LONG_STOP_SEQUENCE)) {
    431     if (512 == frame_len) {
    432       WORD32 *window = (WORD32 *)p_window_next;
    433 
    434       for (i = 0; i < 256; i++) {
    435         lt_pred_stat[(frame_len * 3) + i] =
    436             ixheaacd_round16(ixheaacd_mult16x16in32_shl(
    437                 (WORD16)ixheaacd_shl16(
    438                     (WORD16)-ixheaacd_sat16(overlap[255 - i]), 1),
    439                 (WORD16)ixheaacd_shr32(window[511 - i], 15)));
    440 
    441         lt_pred_stat[(frame_len * 3) + 256 + i] =
    442             ixheaacd_round16(ixheaacd_mult16x16in32_shl(
    443                 (WORD16)ixheaacd_shl16((WORD16)-ixheaacd_sat16(overlap[i]), 1),
    444                 (WORD16)ixheaacd_shr32(window[255 - i], 15)));
    445       }
    446     } else if (480 == frame_len) {
    447       WORD32 *window = (WORD32 *)p_window_next;
    448 
    449       for (i = 0; i < 240; i++) {
    450         lt_pred_stat[(frame_len * 3) + i] =
    451             ixheaacd_round16(ixheaacd_mult16x16in32_shl(
    452                 (WORD16)ixheaacd_shl16(
    453                     (WORD16)-ixheaacd_sat16(overlap[239 - i]), 1),
    454                 (WORD16)ixheaacd_shr32(window[479 - i], 15)));
    455 
    456         lt_pred_stat[(frame_len * 3) + 240 + i] =
    457             ixheaacd_round16(ixheaacd_mult16x16in32_shl(
    458                 (WORD16)ixheaacd_shl16((WORD16)-ixheaacd_sat16(overlap[i]), 1),
    459                 (WORD16)ixheaacd_shr32(window[239 - i], 15)));
    460       }
    461     } else {
    462       for (i = 0; i < 512; i++) {
    463         lt_pred_stat[(frame_len * 2) + i] = ixheaacd_round16(
    464             ixheaacd_shl32_sat(ixheaacd_mult16x16in32_shl(
    465                                    (WORD16)-ixheaacd_sat16(overlap[511 - i]),
    466                                    p_window_next[2 * i + 1]),
    467                                1));
    468 
    469         lt_pred_stat[(frame_len * 2) + 512 + i] =
    470             ixheaacd_round16(ixheaacd_shl32_sat(
    471                 ixheaacd_mult16x16in32_shl((WORD16)-ixheaacd_sat16(overlap[i]),
    472                                            p_window_next[1023 - 2 * i - 1]),
    473                 1));
    474       }
    475     }
    476 
    477   } else if (window_sequence == LONG_START_SEQUENCE) {
    478     for (i = 0; i < 448; i++) {
    479       lt_pred_stat[(frame_len * 2) + i] =
    480           ixheaacd_shl16((WORD16)-ixheaacd_sat16(overlap[511 - i]), 1);
    481     }
    482     for (i = 0; i < 64; i++) {
    483       lt_pred_stat[(frame_len * 2) + 448 + i] =
    484           ixheaacd_round16(ixheaacd_shl32_sat(
    485               ixheaacd_mult16x16in32_shl(
    486                   (WORD16)-ixheaacd_sat16(overlap[511 - 448 - i]),
    487                   p_window_next[2 * i + 1]),
    488               1));
    489     }
    490     for (i = 0; i < 64; i++) {
    491       lt_pred_stat[(frame_len * 2) + 512 + i] =
    492           ixheaacd_round16(ixheaacd_shl32_sat(
    493               ixheaacd_mult16x16in32_shl((WORD16)-ixheaacd_sat16(overlap[i]),
    494                                          p_window_next[127 - 2 * i - 1]),
    495               1));
    496     }
    497     for (i = 576; i < 1024; i++) {
    498       lt_pred_stat[(frame_len * 2) + i] = 0;
    499     }
    500   } else {
    501     for (i = 0; i < 448; i++) {
    502       lt_pred_stat[(frame_len * 2) + i] =
    503           ixheaacd_shl16(ixheaacd_sat16(overlap[i]), 1);
    504     }
    505     for (i = 0; i < 64; i++) {
    506       lt_pred_stat[(frame_len * 2) + 448 + i] = ixheaacd_round16(
    507           ixheaacd_shl32_sat(ixheaacd_mult16x16in32_shl(
    508                                  (WORD16)-ixheaacd_sat16(overlap[511 - i]),
    509                                  p_window_next[2 * i + 1]),
    510                              1));
    511     }
    512     for (i = 0; i < 64; i++) {
    513       lt_pred_stat[(frame_len * 2) + 512 + i] = ixheaacd_round16(
    514           ixheaacd_shl32_sat(ixheaacd_mult16x16in32_shl(
    515                                  (WORD16)-ixheaacd_sat16(overlap[448 + i]),
    516                                  p_window_next[127 - 2 * i - 1]),
    517                              1));
    518     }
    519     for (i = 576; i < 1024; i++) {
    520       lt_pred_stat[(frame_len * 2) + i] = 0;
    521     }
    522   }
    523 }
    524