2 * Copyright (c) 2005-2012 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
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.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * miscellaneous math routines and tables
29 #include "mathematics.h"
30 #include "libavutil/common.h"
34 int64_t av_gcd(int64_t a, int64_t b)
37 return av_gcd(b, a % b);
42 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd)
47 av_assert2((unsigned)(rnd&~AV_ROUND_PASS_MINMAX)<=5 && (rnd&~AV_ROUND_PASS_MINMAX)!=4);
49 if (c <= 0 || b < 0 || !((unsigned)(rnd&~AV_ROUND_PASS_MINMAX)<=5 && (rnd&~AV_ROUND_PASS_MINMAX)!=4))
52 if (rnd & AV_ROUND_PASS_MINMAX) {
53 if (a == INT64_MIN || a == INT64_MAX)
55 rnd -= AV_ROUND_PASS_MINMAX;
58 if (a < 0 && a != INT64_MIN)
59 return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd >> 1) & 1));
61 if (rnd == AV_ROUND_NEAR_INF)
66 if (b <= INT_MAX && c <= INT_MAX) {
68 return (a * b + r) / c;
70 return a / c * b + (a % c * b + r) / c;
73 uint64_t a0 = a & 0xFFFFFFFF;
74 uint64_t a1 = a >> 32;
75 uint64_t b0 = b & 0xFFFFFFFF;
76 uint64_t b1 = b >> 32;
77 uint64_t t1 = a0 * b1 + a1 * b0;
78 uint64_t t1a = t1 << 32;
82 a1 = a1 * b1 + (t1 >> 32) + (a0 < t1a);
86 for (i = 63; i >= 0; i--) {
87 a1 += a1 + ((a0 >> i) & 1);
98 ai = av_mul_i(av_int2i(a), av_int2i(b));
99 ai = av_add_i(ai, av_int2i(r));
101 return av_i2int(av_div_i(ai, av_int2i(c)));
106 int64_t av_rescale(int64_t a, int64_t b, int64_t c)
108 return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
111 int64_t av_rescale_q_rnd(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, rnd);
119 int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
121 return av_rescale_q_rnd(a, bq, cq, AV_ROUND_NEAR_INF);
124 int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b)
126 int64_t a = tb_a.num * (int64_t)tb_b.den;
127 int64_t b = tb_b.num * (int64_t)tb_a.den;
128 if ((FFABS(ts_a)|a|FFABS(ts_b)|b) <= INT_MAX)
129 return (ts_a*a > ts_b*b) - (ts_a*a < ts_b*b);
130 if (av_rescale_rnd(ts_a, a, b, AV_ROUND_DOWN) < ts_b)
132 if (av_rescale_rnd(ts_b, b, a, AV_ROUND_DOWN) < ts_a)
137 int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod)
139 int64_t c = (a - b) & (mod - 1);
145 int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb){
148 av_assert0(in_ts != AV_NOPTS_VALUE);
149 av_assert0(duration >= 0);
151 if (*last == AV_NOPTS_VALUE || !duration || in_tb.num*(int64_t)out_tb.den <= out_tb.num*(int64_t)in_tb.den) {
153 *last = av_rescale_q(in_ts, in_tb, fs_tb) + duration;
154 return av_rescale_q(in_ts, in_tb, out_tb);
157 a = av_rescale_q_rnd(2*in_ts-1, in_tb, fs_tb, AV_ROUND_DOWN) >>1;
158 b = (av_rescale_q_rnd(2*in_ts+1, in_tb, fs_tb, AV_ROUND_UP )+1)>>1;
159 if (*last < 2*a - b || *last > 2*b - a)
162 this = av_clip64(*last, a, b);
163 *last = this + duration;
165 return av_rescale_q(this, fs_tb, out_tb);
168 int64_t av_add_stable(AVRational ts_tb, int64_t ts, AVRational inc_tb, int64_t inc)
173 inc_tb = av_mul_q(inc_tb, (AVRational) {inc, 1});
175 m = inc_tb.num * (int64_t)ts_tb.den;
176 d = inc_tb.den * (int64_t)ts_tb.num;
184 int64_t old = av_rescale_q(ts, ts_tb, inc_tb);
185 int64_t old_ts = av_rescale_q(old, inc_tb, ts_tb);
186 return av_rescale_q(old + 1, inc_tb, ts_tb) + (ts - old_ts);