integer.h (2385B)
1 /* 2 * arbitrary precision integers 3 * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22 /** 23 * @file 24 * arbitrary precision integers 25 * @author Michael Niedermayer <michaelni@gmx.at> 26 */ 27 28 #ifndef AVUTIL_INTEGER_H 29 #define AVUTIL_INTEGER_H 30 31 #include <stdint.h> 32 #include "attributes.h" 33 34 #define AV_INTEGER_SIZE 8 35 36 typedef struct AVInteger{ 37 uint16_t v[AV_INTEGER_SIZE]; 38 } AVInteger; 39 40 AVInteger av_add_i(AVInteger a, AVInteger b) av_const; 41 AVInteger av_sub_i(AVInteger a, AVInteger b) av_const; 42 43 /** 44 * Return the rounded-down value of the base 2 logarithm of the given 45 * AVInteger. This is simply the index of the most significant bit 46 * which is 1, or 0 if all bits are 0. 47 */ 48 int av_log2_i(AVInteger a) av_const; 49 AVInteger av_mul_i(AVInteger a, AVInteger b) av_const; 50 51 /** 52 * Return 0 if a==b, 1 if a>b and -1 if a<b. 53 */ 54 int av_cmp_i(AVInteger a, AVInteger b) av_const; 55 56 /** 57 * bitwise shift 58 * @param s the number of bits by which the value should be shifted right, 59 may be negative for shifting left 60 */ 61 AVInteger av_shr_i(AVInteger a, int s) av_const; 62 63 /** 64 * Return a % b. 65 * @param quot a/b will be stored here. 66 */ 67 AVInteger av_mod_i(AVInteger *quot, AVInteger a, AVInteger b); 68 69 /** 70 * Return a/b. 71 */ 72 AVInteger av_div_i(AVInteger a, AVInteger b) av_const; 73 74 /** 75 * Convert the given int64_t to an AVInteger. 76 */ 77 AVInteger av_int2i(int64_t a) av_const; 78 79 /** 80 * Convert the given AVInteger to an int64_t. 81 * If the AVInteger is too large to fit into an int64_t, 82 * then only the least significant 64 bits will be used. 83 */ 84 int64_t av_i2int(AVInteger a) av_const; 85 86 #endif /* AVUTIL_INTEGER_H */