xref: /aosp_15_r20/external/libxaac/encoder/ixheaace_quant.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 <math.h>
22 
23 #include "ixheaac_type_def.h"
24 #include "ixheaac_constants.h"
25 #include "ixheaace_aac_constants.h"
26 #include "ixheaace_psy_const.h"
27 #include "ixheaace_tns.h"
28 #include "ixheaace_tns_params.h"
29 #include "ixheaace_rom.h"
30 #include "ixheaace_quant.h"
31 #include "ixheaace_common_rom.h"
32 #include "ixheaace_bitbuffer.h"
33 
iaace_quantize_lines(const WORD32 gain,const WORD32 num_lines,FLOAT32 * ptr_exp_spec,WORD16 * ptr_quant_spec,FLOAT32 * ptr_mdct_spec)34 VOID iaace_quantize_lines(const WORD32 gain, const WORD32 num_lines, FLOAT32 *ptr_exp_spec,
35                           WORD16 *ptr_quant_spec, FLOAT32 *ptr_mdct_spec) {
36   FLOAT32 quantizer;
37   FLOAT32 k = -0.0946f + 0.5f;
38   WORD32 line;
39 
40   quantizer = ixheaace_fd_quant_table[gain + 128];
41 
42   for (line = 0; line < num_lines; line++) {
43     FLOAT32 tmp = ptr_mdct_spec[line];
44     if (tmp < 0.0f) {
45       ptr_exp_spec[line] = (FLOAT32)sqrt(-tmp);
46       ptr_exp_spec[line] *= (FLOAT32)sqrt(ptr_exp_spec[line]);
47       ptr_quant_spec[line] = -(WORD16)(k + quantizer * ptr_exp_spec[line]);
48     } else {
49       ptr_exp_spec[line] = (FLOAT32)sqrt(tmp);
50       ptr_exp_spec[line] *= (FLOAT32)sqrt(ptr_exp_spec[line]);
51       ptr_quant_spec[line] = (WORD16)(k + quantizer * ptr_exp_spec[line]);
52     }
53   }
54 }
55