| 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 */ |