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- /*
- * 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 libavutil/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;
- }
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