1 /*
2 * Copyright (c) 2005-2012 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of FFmpeg.
5 *
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.
10 *
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.
15 *
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
19 */
20
21 /**
22 * @file
23 * miscellaneous math routines and tables
24 */
25
26 #include <stdint.h>
28
34
35 /* Stein's binary GCD algorithm:
36 * https://en.wikipedia.org/wiki/Binary_GCD_algorithm */
38 int za, zb, k;
39 int64_t u, v;
40 if (a == 0)
42 if (b == 0)
47 u = llabs(a >> za);
48 v = llabs(b >> zb);
49 while (u != v) {
50 if (u > v)
52 v -= u;
54 }
55 return (uint64_t)u << k;
56 }
57
59 {
64
66 return INT64_MIN;
67
69 if (a == INT64_MIN || a == INT64_MAX)
72 }
73
74 if (a < 0)
76
78 r = c / 2;
79 else if (rnd & 1)
80 r = c - 1;
81
82 if (b <= INT_MAX && c <= INT_MAX) {
83 if (a <= INT_MAX)
84 return (a * b + r) /
c;
85 else {
87 int64_t
a2 = (a % c * b +
r) / c;
88 if (ad >= INT32_MAX && b && ad > (INT64_MAX - a2) /
b)
89 return INT64_MIN;
91 }
92 } else {
93 #if 1
94 uint64_t
a0 = a & 0xFFFFFFFF;
95 uint64_t
a1 = a >> 32;
96 uint64_t b0 = b & 0xFFFFFFFF;
97 uint64_t b1 = b >> 32;
98 uint64_t
t1 = a0 * b1 + a1 * b0;
99 uint64_t t1a = t1 << 32;
100 int i;
101
102 a0 = a0 * b0 + t1a;
103 a1 = a1 * b1 + (t1 >> 32) + (a0 < t1a);
106
107 for (i = 63; i >= 0; i--) {
108 a1 += a1 + ((a0 >> i) & 1);
110 if (c <= a1) {
112 t1++;
113 }
114 }
115 if (t1 > INT64_MAX)
116 return INT64_MIN;
118 }
119 #else
123
125 }
126 #endif
127 }
128
130 {
132 }
133
136 {
137 int64_t
b = bq.
num * (int64_t)cq.
den;
138 int64_t
c = cq.
num * (int64_t)bq.
den;
140 }
141
143 {
145 }
146
148 {
149 int64_t
a = tb_a.
num * (int64_t)tb_b.
den;
150 int64_t
b = tb_b.
num * (int64_t)tb_a.
den;
152 return (ts_a*a > ts_b*
b) - (ts_a*a < ts_b*
b);
154 return -1;
156 return 1;
157 return 0;
158 }
159
161 {
162 int64_t
c = (a -
b) & (mod - 1);
163 if (c > (mod >> 1))
164 c -= mod;
166 }
167
170
173
175 simple_round:
178 }
179
182 if (*last < 2*a - b || *last > 2*b - a)
183 goto simple_round;
184
185 this = av_clip64(*last, a, b);
187
189 }
190
192 {
194
195 if (inc != 1)
197
198 m = inc_tb.
num * (int64_t)ts_tb.
den;
199 d = inc_tb.
den * (int64_t)ts_tb.
num;
200
201 if (m % d == 0)
202 return ts + m / d;
203 if (m < d)
204 return ts;
205
206 {
209 return av_rescale_q(old + 1, inc_tb, ts_tb) + (ts - old_ts);
210 }
211 }
int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd)
Rescale a 64-bit integer with specified rounding.
#define av_assert0(cond)
assert() equivalent, that is always enabled.
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
AVRational av_mul_q(AVRational b, AVRational c)
Multiply two rationals.
int64_t av_i2int(AVInteger a)
Convert the given AVInteger to an int64_t.
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
AVInteger av_int2i(int64_t a)
Convert the given int64_t to an AVInteger.
Round to nearest and halfway cases away from zero.
AVInteger av_mul_i(AVInteger a, AVInteger b)
simple assert() macros that are a bit more flexible than ISO C assert().
int64_t av_gcd(int64_t a, int64_t b)
Compute the greatest common divisor of a and b.
Libavutil version macros.
int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b)
Compare 2 timestamps each in its own timebases.
int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, enum AVRounding rnd)
Rescale a 64-bit integer by 2 rational numbers with specified rounding.
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
AVInteger av_add_i(AVInteger a, AVInteger b)
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb)
Rescale a timestamp while preserving known durations.
rational number numerator/denominator
common internal and external API header
int64_t av_add_stable(AVRational ts_tb, int64_t ts, AVRational inc_tb, int64_t inc)
Add a value to a timestamp.
AVInteger av_div_i(AVInteger a, AVInteger b)
Return a/b.
Flag to pass INT64_MIN/MAX through instead of rescaling, this avoids special cases for AV_NOPTS_VALUE...
#define FFSWAP(type, a, b)
#define AV_NOPTS_VALUE
Undefined timestamp value.
int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod)
Compare 2 integers modulo mod.