libavutil: Utility code from libavcodec moved to a separate library.

Originally committed as revision 4489 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 54 insertions, 0 deletions

diff --git a/libavutil/intfloat_readwrite.c b/libavutil/intfloat_readwrite.c
new file mode 100644
index 0000000000..cf4d495e59
--- /dev/null
+++ b/libavutil/intfloat_readwrite.c
@@ -0,0 +1,54 @@
+/*
+ * portable IEEE float/double read/write functions
+ *
+ * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This library 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.
+ *
+ * This library 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
+ */
+ 
+/**
+ * @file intfloat_readwrite.c
+ * Portable IEEE float/double read/write functions.
+ */
+ 
+#include "common.h"
+
+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));
+}