avfilter/vf_premultiply: add planes option

Signed-off-by: Paul B Mahol <onemda@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index ac32995dea..4c733f016e 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -11077,6 +11077,14 @@ of second stream as alpha.
 
 Both streams must have same dimensions and same pixel format.
 
+The filter accepts the following option:
+
+@table @option
+@item planes
+Set which planes will be processed, unprocessed planes will be copied.
+By default value 0xf, all planes will be processed.
+@end table
+
 @section prewitt
 Apply prewitt operator to input video stream.