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ffmpeg / libavutil / intfloat_readwrite.c @ c11c2bc2

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/*
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 * portable IEEE float/double read/write functions
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 *
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 * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 */
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/**
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 * @file intfloat_readwrite.c
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 * Portable IEEE float/double read/write functions.
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 */
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#include "common.h"
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double av_int2dbl(int64_t v){
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    if(v+v > 0xFFELLU<<52)
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        return 0.0/0.0;
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    return ldexp(((v&(1LL<<52)-1) + (1LL<<52)) * (v>>63|1), (v>>52&0x7FF)-1075);
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}
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float av_int2flt(int32_t v){
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    if(v+v > 0xFF000000U)
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        return 0.0/0.0;
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    return ldexp(((v&0x7FFFFF) + (1<<23)) * (v>>31|1), (v>>23&0xFF)-150);
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}
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int64_t av_dbl2int(double d){
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    int e;
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    if     ( !d) return 0;
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    else if(d-d) return 0x7FF0000000000000LL + ((int64_t)(d<0)<<63) + (d!=d);
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    d= frexp(d, &e);
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    return (int64_t)(d<0)<<63 | (e+1022LL)<<52 | (int64_t)((fabs(d)-0.5)*(1LL<<53));
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}
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int32_t av_flt2int(float d){
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    int e;
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    if     ( !d) return 0;
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    else if(d-d) return 0x7F800000 + ((d<0)<<31) + (d!=d);
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    d= frexp(d, &e);
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    return (d<0)<<31 | (e+126)<<23 | (int64_t)((fabs(d)-0.5)*(1<<24));
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}