integer.h 2.35 KB
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/*
 * arbitrary precision integers
 * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
 *
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 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * 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
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file libavutil/integer.h
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 * arbitrary precision integers
 * @author Michael Niedermayer <michaelni@gmx.at>
 */
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#ifndef AVUTIL_INTEGER_H
#define AVUTIL_INTEGER_H
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#include <stdint.h>
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#include "common.h"
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#define AV_INTEGER_SIZE 8

typedef struct AVInteger{
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    uint16_t v[AV_INTEGER_SIZE];
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} AVInteger;

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AVInteger av_add_i(AVInteger a, AVInteger b) av_const;
AVInteger av_sub_i(AVInteger a, AVInteger b) av_const;
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/**
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 * Returns the rounded-down value of the base 2 logarithm of the given
 * AVInteger. This is simply the index of the most significant bit
 * which is 1, or 0 if all bits are 0.
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 */
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int av_log2_i(AVInteger a) av_const;
AVInteger av_mul_i(AVInteger a, AVInteger b) av_const;
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/**
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 * Returns 0 if a==b, 1 if a>b and -1 if a<b.
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 */
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int av_cmp_i(AVInteger a, AVInteger b) av_const;
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/**
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 * bitwise shift
 * @param s the number of bits by which the value should be shifted right,
            may be negative for shifting left
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 */
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AVInteger av_shr_i(AVInteger a, int s) av_const;
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/**
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 * Returns a % b.
 * @param quot a/b will be stored here.
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 */
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AVInteger av_mod_i(AVInteger *quot, AVInteger a, AVInteger b);
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/**
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 * Returns a/b.
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 */
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AVInteger av_div_i(AVInteger a, AVInteger b) av_const;
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/**
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 * Converts the given int64_t to an AVInteger.
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 */
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AVInteger av_int2i(int64_t a) av_const;
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/**
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 * Converts the given AVInteger to an int64_t.
 * If the AVInteger is too large to fit into an int64_t,
 * then only the least significant 64 bits will be used.
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 */
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int64_t av_i2int(AVInteger a) av_const;
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#endif /* AVUTIL_INTEGER_H */