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, 84 insertions, 0 deletions

diff --git a/libavutil/mathematics.c b/libavutil/mathematics.c
new file mode 100644
index 0000000000..aa3fd74e0c
--- /dev/null
+++ b/libavutil/mathematics.c
@@ -0,0 +1,84 @@
+/*
+ * 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 mathematics.c
+ * Miscellaneous math routines and tables.
+ */
+
+#include "common.h"
+#include "integer.h"
+#include "mathematics.h"
+
+const uint8_t ff_sqrt_tab[128]={
+        0, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5,
+        5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+        9, 9, 9, 9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,11,11,11
+};
+
+const uint8_t ff_log2_tab[256]={
+        0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
+        5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
+        6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+        6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
+};
+
+int64_t ff_gcd(int64_t a, int64_t b){
+    if(b) return ff_gcd(b, a%b);
+    else  return a;
+}
+
+int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
+    AVInteger ai;
+    int64_t r=0;
+    assert(c > 0);
+    assert(b >=0);
+    assert(rnd >=0 && rnd<=5 && rnd!=4);
+    
+    if(a<0 && a != INT64_MIN) return -av_rescale_rnd(-a, b, c, rnd ^ ((rnd>>1)&1)); 
+    
+    if(rnd==AV_ROUND_NEAR_INF) r= c/2;
+    else if(rnd&1)             r= c-1;
+
+    if(b<=INT_MAX && c<=INT_MAX){
+        if(a<=INT_MAX)
+            return (a * b + r)/c;
+        else
+            return a/c*b + (a%c*b + r)/c;
+    }
+    
+    ai= av_mul_i(av_int2i(a), av_int2i(b));
+    ai= av_add_i(ai, av_int2i(r));
+    
+    return av_i2int(av_div_i(ai, av_int2i(c)));
+}
+
+int64_t av_rescale(int64_t a, int64_t b, int64_t c){
+    return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
+}
+
+int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
+    int64_t b= bq.num * (int64_t)cq.den;
+    int64_t c= cq.num * (int64_t)bq.den;
+    return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
+}