ffmpeg/libavutil/intfloat_readwrite.c

55 lines
1.7 KiB
C

/*
* portable IEEE float/double read/write functions
*
* Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file intfloat_readwrite.c
* Portable IEEE float/double read/write functions.
*/
#include "common.h"
double av_int2dbl(int64_t v){
if(v+v > 0xFFELLU<<52)
return 0.0/0.0;
return ldexp(((v&((1LL<<52)-1)) + (1LL<<52)) * (v>>63|1), (v>>52&0x7FF)-1075);
}
float av_int2flt(int32_t v){
if(v+v > 0xFF000000U)
return 0.0/0.0;
return ldexp(((v&0x7FFFFF) + (1<<23)) * (v>>31|1), (v>>23&0xFF)-150);
}
int64_t av_dbl2int(double d){
int e;
if ( !d) return 0;
else if(d-d) return 0x7FF0000000000000LL + ((int64_t)(d<0)<<63) + (d!=d);
d= frexp(d, &e);
return (int64_t)(d<0)<<63 | (e+1022LL)<<52 | (int64_t)((fabs(d)-0.5)*(1LL<<53));
}
int32_t av_flt2int(float d){
int e;
if ( !d) return 0;
else if(d-d) return 0x7F800000 + ((d<0)<<31) + (d!=d);
d= frexp(d, &e);
return (d<0)<<31 | (e+126)<<23 | (int64_t)((fabs(d)-0.5)*(1<<24));
}