X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Fintfloat_readwrite.c;h=261cf76c33ea56191e48477d0f50e790a3422d0c;hb=9b0dfb27ab5e911547d86142cd8f67d296692bad;hp=81d35dad963f47ac5b7294e0c86959d2b6b59ecd;hpb=bf4e3bd2d0263169ebf5d88972ae319ecb0d7a1e;p=ffmpeg

diff --git a/libavutil/intfloat_readwrite.c b/libavutil/intfloat_readwrite.c
index 81d35dad963..261cf76c33e 100644
--- a/libavutil/intfloat_readwrite.c
+++ b/libavutil/intfloat_readwrite.c
@@ -3,30 +3,33 @@
  *
  * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
  *
- * This library is free software; you can redistribute it and/or
+ * 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 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * This library is distributed in the hope that it will be useful,
+ * 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 this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * 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 > 0xFFELLU<<52)
+    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);
 }
@@ -37,6 +40,23 @@ 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 = (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;
@@ -52,3 +72,26 @@ 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= {{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;
+}
+