lavfi/curves: support preset shorthand.

1 files changed, 10 insertions, 2 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index 94fc6f3df5..450f6ab1f2 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2328,8 +2328,10 @@ If there is no key point defined in @code{x=0}, the filter will automatically
 insert a @var{(0;0)} point. In the same way, if there is no key point defined
 in @code{x=1}, the filter will automatically insert a @var{(1;1)} point.
 
-The filter accepts parameters as a list of @var{key}=@var{value} pairs,
-separated by ":".
+The filter accepts parameters as a list of @var{key}=@var{value}
+pairs, separated by ":". If the key of the first options is omitted,
+the arguments are interpreted according to the syntax
+curves[=@var{preset}].
 
 A description of the accepted parameters follows.
 
@@ -2390,6 +2392,12 @@ The previous example can also be achieved with the associated built-in preset:
 @example
 curves=preset=vintage
 @end example
+
+@item
+Or simply:
+@example
+curves=vintage
+@end example
 @end itemize
 
 @section decimate