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, 2 insertions, 8 deletions

diff --git a/libavfilter/buffersink.c b/libavfilter/buffersink.c
index af9a638e4c..6d83a9310c 100644
--- a/libavfilter/buffersink.c
+++ b/libavfilter/buffersink.c
@@ -38,6 +38,7 @@
 #include "buffersink.h"
 #include "filters.h"
 #include "internal.h"
+#include "video.h"
 
 typedef struct BufferSinkContext {
     const AVClass *class;
@@ -377,13 +378,6 @@ static const AVOption abuffersink_options[] = {
 AVFILTER_DEFINE_CLASS(buffersink);
 AVFILTER_DEFINE_CLASS(abuffersink);
 
-static const AVFilterPad avfilter_vsink_buffer_inputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_VIDEO,
-    },
-};
-
 const AVFilter ff_vsink_buffer = {
     .name          = "buffersink",
     .description   = NULL_IF_CONFIG_SMALL("Buffer video frames, and make them available to the end of the filter graph."),
@@ -391,7 +385,7 @@ const AVFilter ff_vsink_buffer = {
     .priv_class    = &buffersink_class,
     .init          = common_init,
     .activate      = activate,
-    FILTER_INPUTS(avfilter_vsink_buffer_inputs),
+    FILTER_INPUTS(ff_video_default_filterpad),
     .outputs       = NULL,
     FILTER_QUERY_FUNC(vsink_query_formats),
 };