1 /*
2  * Copyright (c) 2001-2003 The FFmpeg project
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * ADPCM tables
24  */
25 
26 #include <stdint.h>
27 
28 /* ff_adpcm_step_table[] and ff_adpcm_index_table[] are from the ADPCM
29    reference source */
30 const int8_t ff_adpcm_index_table[16] = {
31     -1, -1, -1, -1, 2, 4, 6, 8,
32     -1, -1, -1, -1, 2, 4, 6, 8,
33 };
34 
35 /**
36  * This is the step table. Note that many programs use slight deviations from
37  * this table, but such deviations are negligible:
38  */
39 const int16_t ff_adpcm_step_table[89] = {
40         7,     8,     9,    10,    11,    12,    13,    14,    16,    17,
41        19,    21,    23,    25,    28,    31,    34,    37,    41,    45,
42        50,    55,    60,    66,    73,    80,    88,    97,   107,   118,
43       130,   143,   157,   173,   190,   209,   230,   253,   279,   307,
44       337,   371,   408,   449,   494,   544,   598,   658,   724,   796,
45       876,   963,  1060,  1166,  1282,  1411,  1552,  1707,  1878,  2066,
46      2272,  2499,  2749,  3024,  3327,  3660,  4026,  4428,  4871,  5358,
47      5894,  6484,  7132,  7845,  8630,  9493, 10442, 11487, 12635, 13899,
48     15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
49 };
50 
51 /* These are for MS-ADPCM */
52 /* ff_adpcm_AdaptationTable[], ff_adpcm_AdaptCoeff1[], and
53    ff_adpcm_AdaptCoeff2[] are from libsndfile */
54 const int16_t ff_adpcm_AdaptationTable[] = {
55     230, 230, 230, 230, 307, 409, 512, 614,
56     768, 614, 512, 409, 307, 230, 230, 230
57 };
58 
59 /** Divided by 4 to fit in 8-bit integers */
60 const uint8_t ff_adpcm_AdaptCoeff1[] = {
61     64, 128, 0, 48, 60, 115, 98
62 };
63 
64 /** Divided by 4 to fit in 8-bit integers */
65 const int8_t ff_adpcm_AdaptCoeff2[] = {
66     0, -64, 0, 16, 0, -52, -58
67 };
68 
69 const int16_t ff_adpcm_yamaha_indexscale[] = {
70     230, 230, 230, 230, 307, 409, 512, 614,
71     230, 230, 230, 230, 307, 409, 512, 614
72 };
73 
74 const int8_t ff_adpcm_yamaha_difflookup[] = {
75      1,  3,  5,  7,  9,  11,  13,  15,
76     -1, -3, -5, -7, -9, -11, -13, -15
77 };
78