AVRational

sample_aspect_ratio
aspect ratio in JPEG JFIF is SAR not DAR !
removed nonsense SAR guessing code
various related cleanups
bugs?

Originally committed as revision 2403 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 61 insertions, 0 deletions

diff --git a/libavcodec/rational.c b/libavcodec/rational.c
new file mode 100644
index 0000000000..f2a579abca
--- /dev/null
+++ b/libavcodec/rational.c
@@ -0,0 +1,61 @@
+/*
+ * Rational numbers
+ * Copyright (c) 2003 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 rational.c
+ * Rational numbers
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+
+//#include <math.h>
+#include <limits.h>
+ 
+#include "common.h"
+#include "avcodec.h"
+#include "rational.h"
+
+AVRational av_mul_q(AVRational b, AVRational c){
+    av_reduce(&b.num, &b.den, b.num * (int64_t)c.num, b.den * (int64_t)c.den, INT_MAX);
+    return b;
+}
+
+AVRational av_div_q(AVRational b, AVRational c){
+    av_reduce(&b.num, &b.den, b.num * (int64_t)c.den, b.den * (int64_t)c.num, INT_MAX);
+    return b;
+}
+
+AVRational av_add_q(AVRational b, AVRational c){
+    av_reduce(&b.num, &b.den, b.num * (int64_t)c.den + c.num * (int64_t)b.den, b.den * (int64_t)c.den, INT_MAX);
+    return b;
+}
+
+AVRational av_sub_q(AVRational b, AVRational c){
+    av_reduce(&b.num, &b.den, b.num * (int64_t)c.den - c.num * (int64_t)b.den, b.den * (int64_t)c.den, INT_MAX);
+    return b;
+}
+
+AVRational av_d2q(double d, int max){
+    AVRational a;
+    int exponent= FFMAX( (int)log2(ABS(d) + 1e-20), 0);
+    int64_t den= 1LL << (61 - exponent);
+    av_reduce(&a.num, &a.den, (int64_t)(d * den + 0.5), den, max);
+
+    return a;
+}