[FFmpeg-cvslog] doc/filters: correct description of overlay_vaapi

[Fei Wang]

ffmpeg | branch: master | Fei Wang <fei.w.wang-at-intel.com at ffmpeg.org> | Fri Aug  5 14:11:18 2022 +0800| [4e0686df390908e8fb8fc0c4ef50252626c3c656] | committer: Haihao Xiang

doc/filters: correct description of overlay_vaapi

Signed-off-by: Fei Wang <fei.w.wang at intel.com>
Reviewed-by: Philip Langdale <philipl at overt.org>
Signed-off-by: Haihao Xiang <haihao.xiang at intel.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4e0686df390908e8fb8fc0c4ef50252626c3c656
---

 doc/filters.texi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index fd894bcaf1..af7d60ca44 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -26181,8 +26181,8 @@ Set the height of the overlaid video on the main video.
 Default value is the height of input overlay video.
 
 @item alpha
-Set blocking detection thresholds. Allowed range is 0.0 to 1.0, it
-requires an input video with alpha channel.
+Set transparency of overlaid video. Allowed range is 0.0 to 1.0.
+Higher value means lower transparency.
 Default value is @code{0.0}.
 
 @end table