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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 | * Shift value left or right depending on sign of offset parameter. | |
66 | * @param value value to shift | |
67 | * @param offset shift offset | |
68 | * | |
69 | * @return value << offset, if offset>=0; value >> -offset - otherwise | |
70 | */ | |
71 | static inline int bidir_sal(int value, int offset) | |
72 | { | |
73 | if(offset < 0) return value >> -offset; | |
74 | else return value << offset; | |
75 | } | |
76 | ||
77 | /** | |
78 | * returns the dot product of 2 int16_t vectors. | |
79 | * @param a input data array | |
80 | * @param b input data array | |
81 | * @param length number of elements | |
82 | * | |
83 | * @return dot product = sum of elementwise products | |
84 | */ | |
85 | int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length); | |
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 */ |