ffmpeg/libavutil/integer.h

83 lines
2.2 KiB
C

/*
* arbitrary precision integers
* Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
/**
* @file integer.h
* arbitrary precision integers
* @author Michael Niedermayer <michaelni@gmx.at>
*/
#ifndef INTEGER_H
#define INTEGER_H
#define AV_INTEGER_SIZE 8
typedef struct AVInteger{
uint16_t v[AV_INTEGER_SIZE];
} AVInteger;
AVInteger av_add_i(AVInteger a, AVInteger b);
AVInteger av_sub_i(AVInteger a, AVInteger b);
/**
* returns the rounded down value of the logarithm of base 2 of the given AVInteger.
* this is simply the index of the most significant bit which is 1. Or 0 of all bits are 0
*/
int av_log2_i(AVInteger a);
AVInteger av_mul_i(AVInteger a, AVInteger b);
/**
* returns 0 if a==b, 1 if a>b and -1 if a<b.
*/
int av_cmp_i(AVInteger a, AVInteger b);
/**
* bitwise shift.
* @param s the number of bits by which the value should be shifted right, may be negative for shifting left
*/
AVInteger av_shr_i(AVInteger a, int s);
/**
* returns a % b.
* @param quot a/b will be stored here
*/
AVInteger av_mod_i(AVInteger *quot, AVInteger a, AVInteger b);
/**
* returns a/b.
*/
AVInteger av_div_i(AVInteger a, AVInteger b);
/**
* converts the given int64_t to an AVInteger.
*/
AVInteger av_int2i(int64_t a);
/**
* 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 64bit will be used
*/
int64_t av_i2int(AVInteger a);
#endif // INTEGER_H