lavfi/blend: use dual input helpers

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

1 files changed, 7 insertions, 0 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index e3544b5b4f..2ac0c46ec0 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2101,6 +2101,13 @@ Value of pixel component at current location for first video frame (top layer).
 @item BOTTOM, B
 Value of pixel component at current location for second video frame (bottom layer).
 @end table
+
+@item shortest
+Force termination when the shortest input terminates. Default is @code{0}.
+@item repeatlast
+Continue applying the last bottom frame after the end of the stream. A value of
+@code{0} disable the filter after the last frame of the bottom layer is reached.
+Default is @code{1}.
 @end table
 
 @subsection Examples