2 * Various fixed-point math operations
4 * Copyright (c) 2008 Vladimir Voroshilov
6 * This file is part of FFmpeg.
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.
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.
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
23 #ifndef AVCODEC_CELP_MATH_H
24 #define AVCODEC_CELP_MATH_H
28 typedef struct CELPMContext {
30 * Return the dot product.
31 * @param a input data array
32 * @param b input data array
33 * @param length number of elements
35 * @return dot product = sum of elementwise products
37 float (*dot_productf)(const float* a, const float* b, int length);
42 * Initialize CELPMContext.
44 void ff_celp_math_init(CELPMContext *c);
45 void ff_celp_math_init_mips(CELPMContext *c);
48 * fixed-point implementation of cosine in [0; PI) domain.
49 * @param arg fixed-point cosine argument, 0 <= arg < 0x4000
51 * @return value of (1<<15) * cos(arg * PI / (1<<14)), -0x8000 <= result <= 0x7fff
53 int16_t ff_cos(uint16_t arg);
56 * fixed-point implementation of exp2(x) in [0; 1] domain.
57 * @param power argument to exp2, 0 <= power <= 0x7fff
59 * @return value of (1<<20) * exp2(power / (1<<15))
60 * 0x8000c <= result <= 0xfffea
62 int ff_exp2(uint16_t power);
66 * @param value function argument, 0 < value <= 7fff ffff
68 * @return value of (1<<15) * log2(value)
70 int ff_log2(uint32_t value);
73 * Shift value left or right depending on sign of offset parameter.
74 * @param value value to shift
75 * @param offset shift offset
77 * @return value << offset, if offset>=0; value >> -offset - otherwise
79 static inline int bidir_sal(int value, int offset)
81 if(offset < 0) return value >> -offset;
82 else return value << offset;
86 * returns the dot product of 2 int16_t vectors.
87 * @param a input data array
88 * @param b input data array
89 * @param length number of elements
91 * @return dot product = sum of elementwise products
93 int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length);
96 * Return the dot product.
97 * @param a input data array
98 * @param b input data array
99 * @param length number of elements
101 * @return dot product = sum of elementwise products
103 float ff_dot_productf(const float* a, const float* b, int length);
105 #endif /* AVCODEC_CELP_MATH_H */