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 28typedef 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 */ 44void ff_celp_math_init(CELPMContext *c); 45void 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 */ 54int 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 */ 62int 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 */ 71static 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 */ 85int64_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 */ 95float ff_dot_productf(const float* a, const float* b, int length); 96 97#endif /* AVCODEC_CELP_MATH_H */ 98