[FFmpeg-devel] [PATCH] eval: add support for pow() function

[Stefano Sabatini]

It is a more search-friendly alternative to the ^ operator.
---
 doc/eval.texi    |    4 ++++
 libavutil/eval.c |    5 +++++
 2 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/doc/eval.texi b/doc/eval.texi
index 25c0ea6..5c19db5 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.
+
+ at 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/eval.c b/libavutil/eval.c
index 3312215..5ae90f0 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
     };
 
-- 
1.7.2.3