remove some warnings due to avctx->execute
[libav.git] / libavutil / rational.c
CommitLineData
5ff85f1d 1/*
89c9ff50 2 * rational numbers
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3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4 *
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5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
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8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
b78e7197 10 * version 2.1 of the License, or (at your option) any later version.
5ff85f1d 11 *
b78e7197 12 * FFmpeg is distributed in the hope that it will be useful,
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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
b78e7197 18 * License along with FFmpeg; if not, write to the Free Software
5509bffa 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
5ff85f1d 20 */
115329f1 21
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22/**
23 * @file rational.c
89c9ff50 24 * rational numbers
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25 * @author Michael Niedermayer <michaelni@gmx.at>
26 */
27
dfcb6b56 28#include <assert.h>
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29//#include <math.h>
30#include <limits.h>
115329f1 31
5ff85f1d 32#include "common.h"
c11c2bc2 33#include "mathematics.h"
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34#include "rational.h"
35
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36int av_reduce(int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max){
37 AVRational a0={0,1}, a1={1,0};
38 int sign= (nom<0) ^ (den<0);
9ce6c138 39 int64_t gcd= av_gcd(FFABS(nom), FFABS(den));
c11c2bc2 40
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41 if(gcd){
42 nom = FFABS(nom)/gcd;
43 den = FFABS(den)/gcd;
44 }
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45 if(nom<=max && den<=max){
46 a1= (AVRational){nom, den};
47 den=0;
48 }
115329f1 49
c11c2bc2 50 while(den){
62b9fc15 51 uint64_t x = nom / den;
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52 int64_t next_den= nom - den*x;
53 int64_t a2n= x*a1.num + a0.num;
54 int64_t a2d= x*a1.den + a0.den;
55
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56 if(a2n > max || a2d > max){
57 if(a1.num) x= (max - a0.num) / a1.num;
58 if(a1.den) x= FFMIN(x, (max - a0.den) / a1.den);
59
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60 if (den*(2*x*a1.den + a0.den) > nom*a1.den)
61 a1 = (AVRational){x*a1.num + a0.num, x*a1.den + a0.den};
62 break;
63 }
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64
65 a0= a1;
66 a1= (AVRational){a2n, a2d};
67 nom= den;
68 den= next_den;
69 }
9ce6c138 70 assert(av_gcd(a1.num, a1.den) <= 1U);
115329f1 71
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72 *dst_nom = sign ? -a1.num : a1.num;
73 *dst_den = a1.den;
115329f1 74
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75 return den==0;
76}
77
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78AVRational av_mul_q(AVRational b, AVRational c){
79 av_reduce(&b.num, &b.den, b.num * (int64_t)c.num, b.den * (int64_t)c.den, INT_MAX);
80 return b;
81}
82
83AVRational av_div_q(AVRational b, AVRational c){
79dc59b7 84 return av_mul_q(b, (AVRational){c.den, c.num});
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85}
86
87AVRational av_add_q(AVRational b, AVRational c){
88 av_reduce(&b.num, &b.den, b.num * (int64_t)c.den + c.num * (int64_t)b.den, b.den * (int64_t)c.den, INT_MAX);
89 return b;
90}
91
92AVRational av_sub_q(AVRational b, AVRational c){
79dc59b7 93 return av_add_q(b, (AVRational){-c.num, c.den});
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94}
95
96AVRational av_d2q(double d, int max){
97 AVRational a;
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98#define LOG2 0.69314718055994530941723212145817656807550013436025
99 int exponent= FFMAX( (int)(log(fabs(d) + 1e-20)/LOG2), 0);
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100 int64_t den= 1LL << (61 - exponent);
101 av_reduce(&a.num, &a.den, (int64_t)(d * den + 0.5), den, max);
102
103 return a;
104}
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105
106int av_nearer_q(AVRational q, AVRational q1, AVRational q2)
107{
108 /* n/d is q, a/b is the median between q1 and q2 */
109 int64_t a = q1.num * (int64_t)q2.den + q2.num * (int64_t)q1.den;
110 int64_t b = 2 * (int64_t)q1.den * q2.den;
111
112 /* rnd_up(a*d/b) > n => a*d/b > n */
113 int64_t x_up = av_rescale_rnd(a, q.den, b, AV_ROUND_UP);
114
115 /* rnd_down(a*d/b) < n => a*d/b < n */
116 int64_t x_down = av_rescale_rnd(a, q.den, b, AV_ROUND_DOWN);
117
118 return ((x_up > q.num) - (x_down < q.num)) * av_cmp_q(q2, q1);
119}
120
121int av_find_nearest_q_idx(AVRational q, const AVRational* q_list)
122{
123 int i, nearest_q_idx = 0;
124 for(i=0; q_list[i].den; i++)
125 if (av_nearer_q(q, q_list[i], q_list[nearest_q_idx]) > 0)
126 nearest_q_idx = i;
127
128 return nearest_q_idx;
129}