Directly #include a bunch of indirectly #included headers.
[libav.git] / libavutil / mathematics.c
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1/*
2 * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
3 *
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4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
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7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
b78e7197 9 * version 2.1 of the License, or (at your option) any later version.
c11c2bc2 10 *
b78e7197 11 * FFmpeg is distributed in the hope that it will be useful,
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12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
b78e7197 17 * License along with FFmpeg; if not, write to the Free Software
5509bffa 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
c11c2bc2 19 */
115329f1 20
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21/**
22 * @file mathematics.c
23 * Miscellaneous math routines and tables.
24 */
25
dfcb6b56 26#include <assert.h>
c11c2bc2 27#include "common.h"
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28#include "mathematics.h"
29
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30const uint8_t ff_sqrt_tab[256]={
31 0, 16, 23, 28, 32, 36, 40, 43, 46, 48, 51, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 77, 79, 80, 82, 84, 85, 87, 88, 90,
32 91, 92, 94, 95, 96, 98, 99,100,102,103,104,105,107,108,109,110,111,112,114,115,116,117,118,119,120,121,122,123,124,125,126,127,
33128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,144,145,146,147,148,149,150,151,151,152,153,154,155,156,156,
34157,158,159,160,160,161,162,163,164,164,165,166,167,168,168,169,170,171,171,172,173,174,174,175,176,176,177,178,179,179,180,181,
35182,182,183,184,184,185,186,186,187,188,188,189,190,190,191,192,192,193,194,194,195,196,196,197,198,198,199,200,200,201,202,202,
36203,204,204,205,205,206,207,207,208,208,209,210,210,211,212,212,213,213,214,215,215,216,216,217,218,218,219,219,220,220,221,222,
37222,223,223,224,224,225,226,226,227,227,228,228,229,230,230,231,231,232,232,233,233,234,235,235,236,236,237,237,238,238,239,239,
38240,240,241,242,242,243,243,244,244,245,245,246,246,247,247,248,248,249,249,250,250,251,251,252,252,253,253,254,254,255,255,255
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39};
40
41const uint8_t ff_log2_tab[256]={
42 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,
43 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,
44 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,
45 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,
46 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,
47 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,
48 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,
49 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
50};
51
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52int64_t av_gcd(int64_t a, int64_t b){
53 if(b) return av_gcd(b, a%b);
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54 else return a;
55}
56
57int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
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58 int64_t r=0;
59 assert(c > 0);
60 assert(b >=0);
61 assert(rnd >=0 && rnd<=5 && rnd!=4);
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62
63 if(a<0 && a != INT64_MIN) return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd>>1)&1));
64
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65 if(rnd==AV_ROUND_NEAR_INF) r= c/2;
66 else if(rnd&1) r= c-1;
67
68 if(b<=INT_MAX && c<=INT_MAX){
69 if(a<=INT_MAX)
70 return (a * b + r)/c;
71 else
72 return a/c*b + (a%c*b + r)/c;
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73 }else{
74#if 1
75 uint64_t a0= a&0xFFFFFFFF;
76 uint64_t a1= a>>32;
77 uint64_t b0= b&0xFFFFFFFF;
78 uint64_t b1= b>>32;
79 uint64_t t1= a0*b1 + a1*b0;
80 uint64_t t1a= t1<<32;
81 int i;
82
83 a0 = a0*b0 + t1a;
84 a1 = a1*b1 + (t1>>32) + (a0<t1a);
85 a0 += r;
86 a1 += a0<r;
115329f1 87
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88 for(i=63; i>=0; i--){
89// int o= a1 & 0x8000000000000000ULL;
90 a1+= a1 + ((a0>>i)&1);
91 t1+=t1;
5c1cb379 92 if(/*o || */c <= a1){
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93 a1 -= c;
94 t1++;
95 }
96 }
97 return t1;
98 }
99#else
100 AVInteger ai;
101 ai= av_mul_i(av_int2i(a), av_int2i(b));
102 ai= av_add_i(ai, av_int2i(r));
115329f1 103
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104 return av_i2int(av_div_i(ai, av_int2i(c)));
105 }
106#endif
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107}
108
109int64_t av_rescale(int64_t a, int64_t b, int64_t c){
110 return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
111}
112
113int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
114 int64_t b= bq.num * (int64_t)cq.den;
115 int64_t c= cq.num * (int64_t)bq.den;
116 return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
117}
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118
119#ifdef TEST
fc861443 120#include "integer.h"
5c1cb379 121#undef printf
f3635240 122int main(void){
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123 int64_t a,b,c,d,e;
124
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125 for(a=7; a<(1LL<<62); a+=a/3+1){
126 for(b=3; b<(1LL<<62); b+=b/4+1){
127 for(c=9; c<(1LL<<62); c+=(c*2)/5+3){
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128 int64_t r= c/2;
129 AVInteger ai;
130 ai= av_mul_i(av_int2i(a), av_int2i(b));
131 ai= av_add_i(ai, av_int2i(r));
132
133 d= av_i2int(av_div_i(ai, av_int2i(c)));
134
135 e= av_rescale(a,b,c);
136
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137 if((double)a * (double)b / (double)c > (1LL<<63))
138 continue;
139
949b1a13 140 if(d!=e) printf("%"PRId64"*%"PRId64"/%"PRId64"= %"PRId64"=%"PRId64"\n", a, b, c, d, e);
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141 }
142 }
143 }
f3635240 144 return 0;
fdb3a341 145}
d1c9b762 146#endif