portable IEEE float/double read/write functions

Originally committed as revision 4457 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2005-07-19 13:29:13 +00:00
parent ba85e70c54
commit ea4377de8c
1 changed files with 28 additions and 0 deletions

View File

@ -992,6 +992,34 @@ int64_t ff_gcd(int64_t a, int64_t b){
else return a;
}
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));
}
/* av_log API */
static int av_log_level = AV_LOG_INFO;