blob: 18888a425d95d8d0dc835b985295f2b73a570711
1 | /* |
2 | * Various fixed-point math operations |
3 | * |
4 | * Copyright (c) 2008 Vladimir Voroshilov |
5 | * |
6 | * This file is part of FFmpeg. |
7 | * |
8 | * FFmpeg is free software; you can redistribute it and/or |
9 | * modify it under the terms of the GNU Lesser General Public |
10 | * License as published by the Free Software Foundation; either |
11 | * version 2.1 of the License, or (at your option) any later version. |
12 | * |
13 | * FFmpeg is distributed in the hope that it will be useful, |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
16 | * Lesser General Public License for more details. |
17 | * |
18 | * You should have received a copy of the GNU Lesser General Public |
19 | * License along with FFmpeg; if not, write to the Free Software |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
21 | */ |
22 | |
23 | #ifndef AVCODEC_CELP_MATH_H |
24 | #define AVCODEC_CELP_MATH_H |
25 | |
26 | #include <stdint.h> |
27 | |
28 | typedef struct CELPMContext { |
29 | /** |
30 | * Return the dot product. |
31 | * @param a input data array |
32 | * @param b input data array |
33 | * @param length number of elements |
34 | * |
35 | * @return dot product = sum of elementwise products |
36 | */ |
37 | float (*dot_productf)(const float* a, const float* b, int length); |
38 | |
39 | }CELPMContext; |
40 | |
41 | /** |
42 | * Initialize CELPMContext. |
43 | */ |
44 | void ff_celp_math_init(CELPMContext *c); |
45 | void ff_celp_math_init_mips(CELPMContext *c); |
46 | |
47 | /** |
48 | * fixed-point implementation of exp2(x) in [0; 1] domain. |
49 | * @param power argument to exp2, 0 <= power <= 0x7fff |
50 | * |
51 | * @return value of (1<<20) * exp2(power / (1<<15)) |
52 | * 0x8000c <= result <= 0xfffea |
53 | */ |
54 | int ff_exp2(uint16_t power); |
55 | |
56 | /** |
57 | * Calculate log2(x). |
58 | * @param value function argument, 0 < value <= 7fff ffff |
59 | * |
60 | * @return value of (1<<15) * log2(value) |
61 | */ |
62 | int ff_log2_q15(uint32_t value); |
63 | |
64 | /** |
65 | * Calculate the dot product of 2 int16_t vectors. |
66 | * @param a input data array |
67 | * @param b input data array |
68 | * @param length number of elements |
69 | * |
70 | * @return dot product = sum of elementwise products |
71 | */ |
72 | int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length); |
73 | |
74 | /** |
75 | * Shift value left or right depending on sign of offset parameter. |
76 | * @param value value to shift |
77 | * @param offset shift offset |
78 | * |
79 | * @return value << offset, if offset>=0; value >> -offset - otherwise |
80 | */ |
81 | static inline int bidir_sal(int value, int offset) |
82 | { |
83 | if(offset < 0) return value >> -offset; |
84 | else return value << offset; |
85 | } |
86 | |
87 | /** |
88 | * Return the dot product. |
89 | * @param a input data array |
90 | * @param b input data array |
91 | * @param length number of elements |
92 | * |
93 | * @return dot product = sum of elementwise products |
94 | */ |
95 | float ff_dot_productf(const float* a, const float* b, int length); |
96 | |
97 | #endif /* AVCODEC_CELP_MATH_H */ |
98 |