lavc: G.723.1 encoder
[libav.git] / libavcodec / celp_math.h
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1/*
2 * Various fixed-point math operations
3 *
4 * Copyright (c) 2008 Vladimir Voroshilov
5 *
2912e87a 6 * This file is part of Libav.
1cf3ee2d 7 *
2912e87a 8 * Libav is free software; you can redistribute it and/or
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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 *
2912e87a 13 * Libav is distributed in the hope that it will be useful,
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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
2912e87a 19 * License along with Libav; if not, write to the Free Software
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20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
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23#ifndef AVCODEC_CELP_MATH_H
24#define AVCODEC_CELP_MATH_H
1cf3ee2d 25
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26#include <stdint.h>
27
1cf3ee2d 28/**
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29 * fixed-point implementation of exp2(x) in [0; 1] domain.
30 * @param power argument to exp2, 0 <= power <= 0x7fff
1cf3ee2d 31 *
ec5bd476 32 * @return value of (1<<20) * exp2(power / (1<<15))
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33 * 0x8000c <= result <= 0xfffea
34 */
35int ff_exp2(uint16_t power);
36
37/**
49bd8e4b 38 * Calculate log2(x).
ec5bd476 39 * @param value function argument, 0 < value <= 7fff ffff
1cf3ee2d 40 *
ec5bd476 41 * @return value of (1<<15) * log2(value)
1cf3ee2d 42 */
f0c07be6 43int ff_log2_q15(uint32_t value);
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44
45/**
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46 * Calculate the dot product of 2 int16_t vectors.
47 * @param a input data array
48 * @param b input data array
49 * @param length number of elements
50 *
51 * @return dot product = sum of elementwise products
52 */
53int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length);
54
55/**
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56 * Shift value left or right depending on sign of offset parameter.
57 * @param value value to shift
58 * @param offset shift offset
ce9eac79 59 *
ec5bd476 60 * @return value << offset, if offset>=0; value >> -offset - otherwise
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61 */
62static inline int bidir_sal(int value, int offset)
63{
64 if(offset < 0) return value >> -offset;
65 else return value << offset;
66}
67
60c25a4b 68#endif /* AVCODEC_CELP_MATH_H */