mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-08-18 23:35:06 +02:00
![Diego Biurrun](/assets/img/avatar_default.png)
and fix GPL/LGPL version mismatches. Originally committed as revision 6577 to svn://svn.ffmpeg.org/ffmpeg/trunk
98 lines
2.9 KiB
C
98 lines
2.9 KiB
C
/*
|
|
* portable IEEE float/double read/write functions
|
|
*
|
|
* Copyright (c) 2005 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 intfloat_readwrite.c
|
|
* Portable IEEE float/double read/write functions.
|
|
*/
|
|
|
|
#include "common.h"
|
|
#include "intfloat_readwrite.h"
|
|
|
|
double av_int2dbl(int64_t v){
|
|
if(v+v > 0xFFEULL<<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);
|
|
}
|
|
|
|
double av_ext2dbl(const AVExtFloat ext){
|
|
uint64_t m = 0;
|
|
int e, i;
|
|
|
|
for (i = 0; i < 8; i++)
|
|
m = (m<<8) + ext.mantissa[i];
|
|
e = (((int)ext.exponent[0]&0x7f)<<8) | ext.exponent[1];
|
|
if (e == 0x7fff && m)
|
|
return 0.0/0.0;
|
|
e -= 16383 + 63; /* In IEEE 80 bits, the whole (i.e. 1.xxxx)
|
|
* mantissa bit is written as opposed to the
|
|
* single and double precision formats */
|
|
if (ext.exponent[0]&0x80)
|
|
m= -m;
|
|
return ldexp(m, e);
|
|
}
|
|
|
|
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));
|
|
}
|
|
|
|
AVExtFloat av_dbl2ext(double d){
|
|
struct AVExtFloat ext= {{0}};
|
|
int e, i; double f; uint64_t m;
|
|
|
|
f = fabs(frexp(d, &e));
|
|
if (f >= 0.5 && f < 1) {
|
|
e += 16382;
|
|
ext.exponent[0] = e>>8;
|
|
ext.exponent[1] = e;
|
|
m = (uint64_t)ldexp(f, 64);
|
|
for (i=0; i < 8; i++)
|
|
ext.mantissa[i] = m>>(56-(i<<3));
|
|
} else if (f != 0.0) {
|
|
ext.exponent[0] = 0x7f; ext.exponent[1] = 0xff;
|
|
if (f != 1/0.0)
|
|
ext.mantissa[0] = ~0;
|
|
}
|
|
if (d < 0)
|
|
ext.exponent[0] |= 0x80;
|
|
return ext;
|
|
}
|
|
|