xref: /aosp_15_r20/external/libxaac/encoder/ixheaace_psy_utils_spreading.c (revision 15dc779a375ca8b5125643b829a8aa4b70d7f451)
1 /******************************************************************************
2  *                                                                            *
3  * Copyright (C) 2023 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 "ixheaac_type_def.h"
22 #include "ixheaac_constants.h"
23 #include "ixheaace_aac_constants.h"
24 
25 #include "ixheaace_psy_utils_spreading.h"
26 
ia_enhaacplus_enc_spreading_max(const WORD32 sfb_active,const FLOAT32 * ptr_mask_low_factor,const FLOAT32 * ptr_mask_high_factor,FLOAT32 * ptr_spreaded_energy)27 VOID ia_enhaacplus_enc_spreading_max(const WORD32 sfb_active, const FLOAT32 *ptr_mask_low_factor,
28                                      const FLOAT32 *ptr_mask_high_factor,
29                                      FLOAT32 *ptr_spreaded_energy) {
30   WORD32 i;
31   FLOAT32 temp;
32   const FLOAT32 *ptr_mask_low = &ptr_mask_low_factor[sfb_active - 2];
33   const FLOAT32 *ptr_mask_high = &ptr_mask_high_factor[1];
34   FLOAT32 temp_nrg = ptr_spreaded_energy[0];
35   FLOAT32 *ptr_spreaded_temp = ptr_spreaded_energy;
36 
37   for (i = sfb_active - 2; i >= 0; i--) {
38     FLOAT32 temp_mask = *ptr_mask_high++;
39     temp = (temp_mask * temp_nrg);
40     temp_nrg = *++ptr_spreaded_temp;
41     if (temp_nrg < temp) {
42       *ptr_spreaded_temp = temp;
43       temp_nrg = temp;
44     }
45   }
46 
47   temp_nrg = ptr_spreaded_energy[sfb_active - 1];
48 
49   for (i = sfb_active - 2; i >= 0; i--) {
50     FLOAT32 temp_mask = *ptr_mask_low--;
51     temp = (temp_mask * temp_nrg);
52     temp_nrg = ptr_spreaded_energy[i];
53     if (temp_nrg < temp) {
54       ptr_spreaded_energy[i] = temp;
55       temp_nrg = temp;
56     }
57   }
58 }
59