diff options
Diffstat (limited to 'libavutil/intfloat_readwrite.c')
| -rw-r--r-- | libavutil/intfloat_readwrite.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/libavutil/intfloat_readwrite.c b/libavutil/intfloat_readwrite.c index 0d27cb8f39..6450de1024 100644 --- a/libavutil/intfloat_readwrite.c +++ b/libavutil/intfloat_readwrite.c @@ -38,6 +38,23 @@ float av_int2flt(int32_t v){ 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 |= (uint64_t)ext.mantissa[i]<<(56-(i<<3)); + 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) + return ldexp(-m, e); + return ldexp(m, e); +} + int64_t av_dbl2int(double d){ int e; if ( !d) return 0; @@ -53,3 +70,29 @@ int32_t av_flt2int(float 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; + 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) { + memset (&ext, 0, 10); + } else { + ext.exponent[0] = 0x7f; ext.exponent[1] = 0xff; + memset (&ext.mantissa, 0, 8); + if (f != 1/0.0) + ext.mantissa[0] = ~0; + } + if (d < 0) + ext.exponent[0] |= 0x80; + return ext; +} + |