From d58ed64a8953d07f33259317a2ea5856d0c91dfd Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefano.sabatini-lala@poste.it>
Date: Mon, 6 Jun 2011 15:00:25 +0200
Subject: [PATCH] eval: add support for pow() function

It is a more search-friendly alternative to the ^ operator.
---
 doc/eval.texi      | 4 ++++
 libavutil/avutil.h | 2 +-
 libavutil/eval.c   | 5 +++++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/doc/eval.texi b/doc/eval.texi
index 25c0ea6524..ac27750851 100644
--- a/doc/eval.texi
+++ b/doc/eval.texi
@@ -79,6 +79,10 @@ Compute the square root of @var{expr}. This is equivalent to
 
 @item not(expr)
 Return 1.0 if @var{expr} is zero, 0.0 otherwise.
+
+@item pow(x, y)
+Compute the power of @var{x} elevated @var{y}, it is equivalent to
+"(@var{x})^(@var{y})".
 @end table
 
 Note that:
diff --git a/libavutil/avutil.h b/libavutil/avutil.h
index 1912d20170..bd3ff706ea 100644
--- a/libavutil/avutil.h
+++ b/libavutil/avutil.h
@@ -41,7 +41,7 @@
 
 #define LIBAVUTIL_VERSION_MAJOR 51
 #define LIBAVUTIL_VERSION_MINOR  6
-#define LIBAVUTIL_VERSION_MICRO  0
+#define LIBAVUTIL_VERSION_MICRO  1
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
                                                LIBAVUTIL_VERSION_MINOR, \
diff --git a/libavutil/eval.c b/libavutil/eval.c
index 331221515e..5ae90f06d1 100644
--- a/libavutil/eval.c
+++ b/libavutil/eval.c
@@ -290,6 +290,7 @@ static int parse_primary(AVExpr **e, Parser *p)
     else if (strmatch(next, "trunc" )) d->type = e_trunc;
     else if (strmatch(next, "sqrt"  )) d->type = e_sqrt;
     else if (strmatch(next, "not"   )) d->type = e_not;
+    else if (strmatch(next, "pow"   )) d->type = e_pow;
     else {
         for (i=0; p->func1_names && p->func1_names[i]; i++) {
             if (strmatch(next, p->func1_names[i])) {
@@ -643,6 +644,10 @@ int main(void)
         "not(1)",
         "not(NAN)",
         "not(0)",
+        "pow(0,1.23)",
+        "pow(PI,1.23)",
+        "PI^1.23",
+        "pow(-1,1.23)",
         NULL
     };