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#include <inttypes.h> 24#include <limits.h> 25 26#include "libavutil/avassert.h" 27#include "avcodec.h" 28#include "mathops.h" 29#include "celp_math.h" 30#include "libavutil/common.h" 31 32static const uint16_t exp2a[]= 33{ 34 0, 1435, 2901, 4400, 5931, 7496, 9096, 10730, 35 12400, 14106, 15850, 17632, 19454, 21315, 23216, 25160, 36 27146, 29175, 31249, 33368, 35534, 37747, 40009, 42320, 37 44682, 47095, 49562, 52082, 54657, 57289, 59979, 62727, 38}; 39 40static const uint16_t exp2b[]= 41{ 42 3, 712, 1424, 2134, 2845, 3557, 4270, 4982, 43 5696, 6409, 7124, 7839, 8554, 9270, 9986, 10704, 44 11421, 12138, 12857, 13576, 14295, 15014, 15734, 16455, 45 17176, 17898, 18620, 19343, 20066, 20790, 21514, 22238, 46}; 47 48int ff_exp2(uint16_t power) 49{ 50 unsigned int result= exp2a[power>>10] + 0x10000; 51 52 av_assert2(power <= 0x7fff); 53 54 result= (result<<3) + ((result*exp2b[(power>>5)&31])>>17); 55 return result + ((result*(power&31)*89)>>22); 56} 57 58/** 59 * Table used to compute log2(x) 60 * 61 * tab_log2[i] = (1<<15) * log2(1 + i/32), i=0..32 62 */ 63static const uint16_t tab_log2[33] = 64{ 65#ifdef G729_BITEXACT 66 0, 1455, 2866, 4236, 5568, 6863, 8124, 9352, 67 10549, 11716, 12855, 13967, 15054, 16117, 17156, 18172, 68 19167, 20142, 21097, 22033, 22951, 23852, 24735, 25603, 69 26455, 27291, 28113, 28922, 29716, 30497, 31266, 32023, 32767, 70#else 71 4, 1459, 2870, 4240, 5572, 6867, 8127, 9355, 72 10552, 11719, 12858, 13971, 15057, 16120, 17158, 18175, 73 19170, 20145, 21100, 22036, 22954, 23854, 24738, 25605, 74 26457, 27294, 28116, 28924, 29719, 30500, 31269, 32025, 32769, 75#endif 76}; 77 78int ff_log2_q15(uint32_t value) 79{ 80 uint8_t power_int; 81 uint8_t frac_x0; 82 uint16_t frac_dx; 83 84 // Stripping zeros from beginning 85 power_int = av_log2(value); 86 value <<= (31 - power_int); 87 88 // b31 is always non-zero now 89 frac_x0 = (value & 0x7c000000) >> 26; // b26-b31 and [32..63] -> [0..31] 90 frac_dx = (value & 0x03fff800) >> 11; 91 92 value = tab_log2[frac_x0]; 93 value += (frac_dx * (tab_log2[frac_x0+1] - tab_log2[frac_x0])) >> 15; 94 95 return (power_int << 15) + value; 96} 97 98int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length) 99{ 100 int i; 101 int64_t sum = 0; 102 103 for (i = 0; i < length; i++) 104 sum += MUL16(a[i], b[i]); 105 106 return sum; 107} 108 109float ff_dot_productf(const float* a, const float* b, int length) 110{ 111 float sum = 0; 112 int i; 113 114 for(i=0; i<length; i++) 115 sum += a[i] * b[i]; 116 117 return sum; 118} 119 120void ff_celp_math_init(CELPMContext *c) 121{ 122 c->dot_productf = ff_dot_productf; 123 124 if(HAVE_MIPSFPU) 125 ff_celp_math_init_mips(c); 126} 127