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Diffstat (limited to 'media/libav/libavutil/mathematics.c')
| -rw-r--r-- | media/libav/libavutil/mathematics.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/media/libav/libavutil/mathematics.c b/media/libav/libavutil/mathematics.c new file mode 100644 index 000000000..f36623a0b --- /dev/null +++ b/media/libav/libavutil/mathematics.c @@ -0,0 +1,151 @@ +/* + * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at> + * + * This file is part of Libav. + * + * Libav is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * Libav is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * miscellaneous math routines and tables + */ + +#include <stdint.h> +#include <limits.h> + +#include "mathematics.h" +#include "version.h" + +#if FF_API_AV_REVERSE +const uint8_t av_reverse[256] = { +0x00,0x80,0x40,0xC0,0x20,0xA0,0x60,0xE0,0x10,0x90,0x50,0xD0,0x30,0xB0,0x70,0xF0, +0x08,0x88,0x48,0xC8,0x28,0xA8,0x68,0xE8,0x18,0x98,0x58,0xD8,0x38,0xB8,0x78,0xF8, +0x04,0x84,0x44,0xC4,0x24,0xA4,0x64,0xE4,0x14,0x94,0x54,0xD4,0x34,0xB4,0x74,0xF4, +0x0C,0x8C,0x4C,0xCC,0x2C,0xAC,0x6C,0xEC,0x1C,0x9C,0x5C,0xDC,0x3C,0xBC,0x7C,0xFC, +0x02,0x82,0x42,0xC2,0x22,0xA2,0x62,0xE2,0x12,0x92,0x52,0xD2,0x32,0xB2,0x72,0xF2, +0x0A,0x8A,0x4A,0xCA,0x2A,0xAA,0x6A,0xEA,0x1A,0x9A,0x5A,0xDA,0x3A,0xBA,0x7A,0xFA, +0x06,0x86,0x46,0xC6,0x26,0xA6,0x66,0xE6,0x16,0x96,0x56,0xD6,0x36,0xB6,0x76,0xF6, +0x0E,0x8E,0x4E,0xCE,0x2E,0xAE,0x6E,0xEE,0x1E,0x9E,0x5E,0xDE,0x3E,0xBE,0x7E,0xFE, +0x01,0x81,0x41,0xC1,0x21,0xA1,0x61,0xE1,0x11,0x91,0x51,0xD1,0x31,0xB1,0x71,0xF1, +0x09,0x89,0x49,0xC9,0x29,0xA9,0x69,0xE9,0x19,0x99,0x59,0xD9,0x39,0xB9,0x79,0xF9, +0x05,0x85,0x45,0xC5,0x25,0xA5,0x65,0xE5,0x15,0x95,0x55,0xD5,0x35,0xB5,0x75,0xF5, +0x0D,0x8D,0x4D,0xCD,0x2D,0xAD,0x6D,0xED,0x1D,0x9D,0x5D,0xDD,0x3D,0xBD,0x7D,0xFD, +0x03,0x83,0x43,0xC3,0x23,0xA3,0x63,0xE3,0x13,0x93,0x53,0xD3,0x33,0xB3,0x73,0xF3, +0x0B,0x8B,0x4B,0xCB,0x2B,0xAB,0x6B,0xEB,0x1B,0x9B,0x5B,0xDB,0x3B,0xBB,0x7B,0xFB, +0x07,0x87,0x47,0xC7,0x27,0xA7,0x67,0xE7,0x17,0x97,0x57,0xD7,0x37,0xB7,0x77,0xF7, +0x0F,0x8F,0x4F,0xCF,0x2F,0xAF,0x6F,0xEF,0x1F,0x9F,0x5F,0xDF,0x3F,0xBF,0x7F,0xFF, +}; +#endif + +int64_t av_gcd(int64_t a, int64_t b) +{ + if (b) + return av_gcd(b, a % b); + else + return a; +} + +int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd) +{ + int64_t r = 0; + + if (c <= 0 || b < 0 || rnd == 4 || rnd > 5) + return INT64_MIN; + + if (a < 0 && a != INT64_MIN) + return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd >> 1) & 1)); + + if (rnd == AV_ROUND_NEAR_INF) + r = c / 2; + else if (rnd & 1) + r = c - 1; + + if (b <= INT_MAX && c <= INT_MAX) { + if (a <= INT_MAX) + return (a * b + r) / c; + else + return a / c * b + (a % c * b + r) / c; + } else { +#if 1 + uint64_t a0 = a & 0xFFFFFFFF; + uint64_t a1 = a >> 32; + uint64_t b0 = b & 0xFFFFFFFF; + uint64_t b1 = b >> 32; + uint64_t t1 = a0 * b1 + a1 * b0; + uint64_t t1a = t1 << 32; + int i; + + a0 = a0 * b0 + t1a; + a1 = a1 * b1 + (t1 >> 32) + (a0 < t1a); + a0 += r; + a1 += a0 < r; + + for (i = 63; i >= 0; i--) { + a1 += a1 + ((a0 >> i) & 1); + t1 += t1; + if (c <= a1) { + a1 -= c; + t1++; + } + } + return t1; + } +#else + AVInteger ai; + ai = av_mul_i(av_int2i(a), av_int2i(b)); + ai = av_add_i(ai, av_int2i(r)); + + return av_i2int(av_div_i(ai, av_int2i(c))); + } +#endif +} + +int64_t av_rescale(int64_t a, int64_t b, int64_t c) +{ + return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF); +} + +int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, + enum AVRounding rnd) +{ + int64_t b = bq.num * (int64_t)cq.den; + int64_t c = cq.num * (int64_t)bq.den; + return av_rescale_rnd(a, b, c, rnd); +} + +int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) +{ + return av_rescale_q_rnd(a, bq, cq, AV_ROUND_NEAR_INF); +} + +int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b) +{ + int64_t a = tb_a.num * (int64_t)tb_b.den; + int64_t b = tb_b.num * (int64_t)tb_a.den; + if (av_rescale_rnd(ts_a, a, b, AV_ROUND_DOWN) < ts_b) + return -1; + if (av_rescale_rnd(ts_b, b, a, AV_ROUND_DOWN) < ts_a) + return 1; + return 0; +} + +int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod) +{ + int64_t c = (a - b) & (mod - 1); + if (c > (mod >> 1)) + c -= mod; + return c; +} |