xref: /aosp_15_r20/external/libxaac/encoder/ixheaace_sbr_crc.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 <string.h>
22 
23 #include "ixheaac_type_def.h"
24 #include "ixheaac_constants.h"
25 #include "ixheaace_aac_constants.h"
26 #include "ixheaac_basic_ops32.h"
27 #include "ixheaac_basic_ops16.h"
28 #include "ixheaac_basic_ops40.h"
29 
30 #include "ixheaace_bitbuffer.h"
31 #include "ixheaace_sbr_def.h"
32 #include "ixheaace_sbr_cmondata.h"
33 #include "ixheaace_sbr_crc.h"
34 #include "ixheaace_common_utils.h"
35 
ixheaace_crc_advance(UWORD16 crc_poly,UWORD16 crc_mask,UWORD16 * ptr_crc,UWORD32 b_value,WORD32 b_bits)36 static VOID ixheaace_crc_advance(UWORD16 crc_poly, UWORD16 crc_mask, UWORD16 *ptr_crc,
37                                  UWORD32 b_value, WORD32 b_bits) {
38   WORD32 i = b_bits - 1;
39 
40   while (i >= 0) {
41     UWORD16 flag = (*ptr_crc) & crc_mask ? 1 : 0;
42 
43     flag ^= (b_value & (1 << i) ? 1 : 0);
44 
45     (*ptr_crc) <<= 1;
46 
47     if (flag) {
48       (*ptr_crc) ^= crc_poly;
49     }
50     i--;
51   }
52 }
53 
ixheaace_init_sbr_bitstream(ixheaace_pstr_common_data pstr_cmon_data,UWORD8 * ptr_memory_base,WORD32 memory_size,WORD32 crc_active,ixheaace_sbr_codec_type sbr_codec)54 VOID ixheaace_init_sbr_bitstream(ixheaace_pstr_common_data pstr_cmon_data,
55                                  UWORD8 *ptr_memory_base, WORD32 memory_size, WORD32 crc_active,
56                                  ixheaace_sbr_codec_type sbr_codec) {
57   ixheaace_reset_bitbuf(&pstr_cmon_data->str_sbr_bit_buf, ptr_memory_base, memory_size);
58 
59   pstr_cmon_data->str_tmp_write_bit_buf = pstr_cmon_data->str_sbr_bit_buf;
60   if (HEAAC_SBR == sbr_codec) {
61     ixheaace_write_bits(&pstr_cmon_data->str_sbr_bit_buf, 0, SI_FILL_EXTENTION_BITS);
62 
63     if (crc_active) {
64       ixheaace_write_bits(&pstr_cmon_data->str_sbr_bit_buf, 0, SI_CRC_BITS_SBR);
65     }
66   }
67 }
68 
ixheaace_assemble_sbr_bitstream(ixheaace_pstr_common_data pstr_cmon_data,ixheaace_sbr_codec_type sbr_codec)69 VOID ixheaace_assemble_sbr_bitstream(ixheaace_pstr_common_data pstr_cmon_data,
70                                      ixheaace_sbr_codec_type sbr_codec) {
71   UWORD16 crc_reg = CRCINIT_SBR;
72   WORD32 num_crc_bits, i;
73   WORD32 sbr_load = 0;
74 
75   sbr_load = pstr_cmon_data->sbr_hdr_bits + pstr_cmon_data->sbr_data_bits;
76 
77   if (HEAAC_SBR == sbr_codec) {
78     sbr_load += SI_FILL_EXTENTION_BITS;
79   }
80 
81   if (pstr_cmon_data->sbr_crc_len) {
82     sbr_load += SI_CRC_BITS_SBR;
83   }
84 
85   if (USAC_SBR != sbr_codec) {
86     pstr_cmon_data->sbr_fill_bits = (8 - (sbr_load) % 8) % 8;
87 
88     ixheaace_write_bits(&pstr_cmon_data->str_sbr_bit_buf, 0,
89                         (UWORD8)pstr_cmon_data->sbr_fill_bits);
90   }
91   if (pstr_cmon_data->sbr_crc_len) {
92     ixheaace_bit_buf tmp_crc_buf = pstr_cmon_data->str_sbr_bit_buf;
93 
94     ixheaace_readbits(&tmp_crc_buf, SI_FILL_EXTENTION_BITS);
95 
96     ixheaace_readbits(&tmp_crc_buf, SI_CRC_BITS_SBR);
97 
98     num_crc_bits = pstr_cmon_data->sbr_hdr_bits + pstr_cmon_data->sbr_data_bits +
99                    pstr_cmon_data->sbr_fill_bits;
100 
101     i = 0;
102     while (i < num_crc_bits) {
103       UWORD32 bit;
104 
105       bit = ixheaace_readbits(&tmp_crc_buf, 1);
106 
107       ixheaace_crc_advance(CRC_POLYNOMIAL_SBR, CRC_MASK_SBR, &crc_reg, bit, 1);
108 
109       i++;
110     }
111 
112     crc_reg &= (CRC_RANGE_SBR);
113   }
114 
115   if (pstr_cmon_data->sbr_crc_len) {
116     ixheaace_write_bits(&pstr_cmon_data->str_tmp_write_bit_buf, SI_FIL_CRC_SBR,
117                         SI_FILL_EXTENTION_BITS);
118 
119     ixheaace_write_bits(&pstr_cmon_data->str_tmp_write_bit_buf, crc_reg, SI_CRC_BITS_SBR);
120   } else {
121     if (HEAAC_SBR == sbr_codec) {
122       ixheaace_write_bits(&pstr_cmon_data->str_tmp_write_bit_buf, SI_FIL_SBR,
123                           SI_FILL_EXTENTION_BITS);
124     }
125   }
126 }
127