Create symbolic links for all library sonames and clean up Makefiles.
[libav.git] / libavutil / mathematics.c
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1/*
2 * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
5509bffa 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
c11c2bc2 17 */
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19/**
20 * @file mathematics.c
21 * Miscellaneous math routines and tables.
22 */
23
24#include "common.h"
25#include "integer.h"
26#include "mathematics.h"
27
28const uint8_t ff_sqrt_tab[128]={
29 0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5,
30 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
31 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
32 9, 9, 9, 9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11
33};
34
35const uint8_t ff_log2_tab[256]={
36 0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
37 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
38 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
39 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
40 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
41 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
42 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
43 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
44};
45
46int64_t ff_gcd(int64_t a, int64_t b){
47 if(b) return ff_gcd(b, a%b);
48 else return a;
49}
50
51int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
52 AVInteger ai;
53 int64_t r=0;
54 assert(c > 0);
55 assert(b >=0);
56 assert(rnd >=0 && rnd<=5 && rnd!=4);
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57
58 if(a<0 && a != INT64_MIN) return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd>>1)&1));
59
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60 if(rnd==AV_ROUND_NEAR_INF) r= c/2;
61 else if(rnd&1) r= c-1;
62
63 if(b<=INT_MAX && c<=INT_MAX){
64 if(a<=INT_MAX)
65 return (a * b + r)/c;
66 else
67 return a/c*b + (a%c*b + r)/c;
68 }
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70 ai= av_mul_i(av_int2i(a), av_int2i(b));
71 ai= av_add_i(ai, av_int2i(r));
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73 return av_i2int(av_div_i(ai, av_int2i(c)));
74}
75
76int64_t av_rescale(int64_t a, int64_t b, int64_t c){
77 return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
78}
79
80int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
81 int64_t b= bq.num * (int64_t)cq.den;
82 int64_t c= cq.num * (int64_t)bq.den;
83 return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
84}