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> 27#include <limits.h> 28 29#include "mathematics.h" 30#include "libavutil/common.h" 31#include "avassert.h" 32#include "version.h" 33 34#if FF_API_AV_REVERSE 35const uint8_t av_reverse[256] = { 360x00,0x80,0x40,0xC0,0x20,0xA0,0x60,0xE0,0x10,0x90,0x50,0xD0,0x30,0xB0,0x70,0xF0, 370x08,0x88,0x48,0xC8,0x28,0xA8,0x68,0xE8,0x18,0x98,0x58,0xD8,0x38,0xB8,0x78,0xF8, 380x04,0x84,0x44,0xC4,0x24,0xA4,0x64,0xE4,0x14,0x94,0x54,0xD4,0x34,0xB4,0x74,0xF4, 390x0C,0x8C,0x4C,0xCC,0x2C,0xAC,0x6C,0xEC,0x1C,0x9C,0x5C,0xDC,0x3C,0xBC,0x7C,0xFC, 400x02,0x82,0x42,0xC2,0x22,0xA2,0x62,0xE2,0x12,0x92,0x52,0xD2,0x32,0xB2,0x72,0xF2, 410x0A,0x8A,0x4A,0xCA,0x2A,0xAA,0x6A,0xEA,0x1A,0x9A,0x5A,0xDA,0x3A,0xBA,0x7A,0xFA, 420x06,0x86,0x46,0xC6,0x26,0xA6,0x66,0xE6,0x16,0x96,0x56,0xD6,0x36,0xB6,0x76,0xF6, 430x0E,0x8E,0x4E,0xCE,0x2E,0xAE,0x6E,0xEE,0x1E,0x9E,0x5E,0xDE,0x3E,0xBE,0x7E,0xFE, 440x01,0x81,0x41,0xC1,0x21,0xA1,0x61,0xE1,0x11,0x91,0x51,0xD1,0x31,0xB1,0x71,0xF1, 450x09,0x89,0x49,0xC9,0x29,0xA9,0x69,0xE9,0x19,0x99,0x59,0xD9,0x39,0xB9,0x79,0xF9, 460x05,0x85,0x45,0xC5,0x25,0xA5,0x65,0xE5,0x15,0x95,0x55,0xD5,0x35,0xB5,0x75,0xF5, 470x0D,0x8D,0x4D,0xCD,0x2D,0xAD,0x6D,0xED,0x1D,0x9D,0x5D,0xDD,0x3D,0xBD,0x7D,0xFD, 480x03,0x83,0x43,0xC3,0x23,0xA3,0x63,0xE3,0x13,0x93,0x53,0xD3,0x33,0xB3,0x73,0xF3, 490x0B,0x8B,0x4B,0xCB,0x2B,0xAB,0x6B,0xEB,0x1B,0x9B,0x5B,0xDB,0x3B,0xBB,0x7B,0xFB, 500x07,0x87,0x47,0xC7,0x27,0xA7,0x67,0xE7,0x17,0x97,0x57,0xD7,0x37,0xB7,0x77,0xF7, 510x0F,0x8F,0x4F,0xCF,0x2F,0xAF,0x6F,0xEF,0x1F,0x9F,0x5F,0xDF,0x3F,0xBF,0x7F,0xFF, 52}; 53#endif 54 55int64_t av_gcd(int64_t a, int64_t b) 56{ 57 if (b) 58 return av_gcd(b, a % b); 59 else 60 return a; 61} 62 63int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd) 64{ 65 int64_t r = 0; 66 av_assert2(c > 0); 67 av_assert2(b >=0); 68 av_assert2((unsigned)(rnd&~AV_ROUND_PASS_MINMAX)<=5 && (rnd&~AV_ROUND_PASS_MINMAX)!=4); 69 70 if (c <= 0 || b < 0 || !((unsigned)(rnd&~AV_ROUND_PASS_MINMAX)<=5 && (rnd&~AV_ROUND_PASS_MINMAX)!=4)) 71 return INT64_MIN; 72 73 if (rnd & AV_ROUND_PASS_MINMAX) { 74 if (a == INT64_MIN || a == INT64_MAX) 75 return a; 76 rnd -= AV_ROUND_PASS_MINMAX; 77 } 78 79 if (a < 0 && a != INT64_MIN) 80 return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd >> 1) & 1)); 81 82 if (rnd == AV_ROUND_NEAR_INF) 83 r = c / 2; 84 else if (rnd & 1) 85 r = c - 1; 86 87 if (b <= INT_MAX && c <= INT_MAX) { 88 if (a <= INT_MAX) 89 return (a * b + r) / c; 90 else 91 return a / c * b + (a % c * b + r) / c; 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); 104 a0 += r; 105 a1 += a0 < r; 106 107 for (i = 63; i >= 0; i--) { 108 a1 += a1 + ((a0 >> i) & 1); 109 t1 += t1; 110 if (c <= a1) { 111 a1 -= c; 112 t1++; 113 } 114 } 115 return t1; 116 } 117#else 118 AVInteger ai; 119 ai = av_mul_i(av_int2i(a), av_int2i(b)); 120 ai = av_add_i(ai, av_int2i(r)); 121 122 return av_i2int(av_div_i(ai, av_int2i(c))); 123 } 124#endif 125} 126 127int64_t av_rescale(int64_t a, int64_t b, int64_t c) 128{ 129 return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF); 130} 131 132int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, 133 enum AVRounding rnd) 134{ 135 int64_t b = bq.num * (int64_t)cq.den; 136 int64_t c = cq.num * (int64_t)bq.den; 137 return av_rescale_rnd(a, b, c, rnd); 138} 139 140int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) 141{ 142 return av_rescale_q_rnd(a, bq, cq, AV_ROUND_NEAR_INF); 143} 144 145int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b) 146{ 147 int64_t a = tb_a.num * (int64_t)tb_b.den; 148 int64_t b = tb_b.num * (int64_t)tb_a.den; 149 if ((FFABS(ts_a)|a|FFABS(ts_b)|b) <= INT_MAX) 150 return (ts_a*a > ts_b*b) - (ts_a*a < ts_b*b); 151 if (av_rescale_rnd(ts_a, a, b, AV_ROUND_DOWN) < ts_b) 152 return -1; 153 if (av_rescale_rnd(ts_b, b, a, AV_ROUND_DOWN) < ts_a) 154 return 1; 155 return 0; 156} 157 158int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod) 159{ 160 int64_t c = (a - b) & (mod - 1); 161 if (c > (mod >> 1)) 162 c -= mod; 163 return c; 164} 165 166int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb){ 167 int64_t a, b, this; 168 169 av_assert0(in_ts != AV_NOPTS_VALUE); 170 av_assert0(duration >= 0); 171 172 if (*last == AV_NOPTS_VALUE || !duration || in_tb.num*(int64_t)out_tb.den <= out_tb.num*(int64_t)in_tb.den) { 173simple_round: 174 *last = av_rescale_q(in_ts, in_tb, fs_tb) + duration; 175 return av_rescale_q(in_ts, in_tb, out_tb); 176 } 177 178 a = av_rescale_q_rnd(2*in_ts-1, in_tb, fs_tb, AV_ROUND_DOWN) >>1; 179 b = (av_rescale_q_rnd(2*in_ts+1, in_tb, fs_tb, AV_ROUND_UP )+1)>>1; 180 if (*last < 2*a - b || *last > 2*b - a) 181 goto simple_round; 182 183 this = av_clip64(*last, a, b); 184 *last = this + duration; 185 186 return av_rescale_q(this, fs_tb, out_tb); 187} 188 189int64_t av_add_stable(AVRational ts_tb, int64_t ts, AVRational inc_tb, int64_t inc) 190{ 191 int64_t m, d; 192 193 if (inc != 1) 194 inc_tb = av_mul_q(inc_tb, (AVRational) {inc, 1}); 195 196 m = inc_tb.num * (int64_t)ts_tb.den; 197 d = inc_tb.den * (int64_t)ts_tb.num; 198 199 if (m % d == 0) 200 return ts + m / d; 201 if (m < d) 202 return ts; 203 204 { 205 int64_t old = av_rescale_q(ts, ts_tb, inc_tb); 206 int64_t old_ts = av_rescale_q(old, inc_tb, ts_tb); 207 return av_rescale_q(old + 1, inc_tb, ts_tb) + (ts - old_ts); 208 } 209} 210