avfilter: Deduplicate default video inputs/outputs

Lots of video filters use a very simple input or output:
An array with a single AVFilterPad whose name is "default"
and whose type is AVMEDIA_TYPE_VIDEO; everything else is unset.

Given that we never use pointer equality for inputs or outputs*,
we can simply use a single AVFilterPad instead of dozens; this
even saves .data.rel.ro (8312B here) as well as relocations.

*: In fact, several filters (like the filters in vf_lut.c)
already use the same outputs; furthermore, ff_filter_alloc()
duplicates the input and output pads so that we do not even
work with the pads directly.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 1 insertions, 8 deletions

diff --git a/libavfilter/vf_elbg.c b/libavfilter/vf_elbg.c
index d1166714fc..cc49b8e240 100644
--- a/libavfilter/vf_elbg.c
+++ b/libavfilter/vf_elbg.c
@@ -253,13 +253,6 @@ static const AVFilterPad elbg_inputs[] = {
     },
 };
 
-static const AVFilterPad elbg_outputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_VIDEO,
-    },
-};
-
 const AVFilter ff_vf_elbg = {
     .name          = "elbg",
     .description   = NULL_IF_CONFIG_SMALL("Apply posterize effect, using the ELBG algorithm."),
@@ -268,6 +261,6 @@ const AVFilter ff_vf_elbg = {
     .init          = init,
     .uninit        = uninit,
     FILTER_INPUTS(elbg_inputs),
-    FILTER_OUTPUTS(elbg_outputs),
+    FILTER_OUTPUTS(ff_video_default_filterpad),
     FILTER_QUERY_FUNC(query_formats),
 };