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, 3 insertions, 16 deletions

diff --git a/libavfilter/f_cue.c b/libavfilter/f_cue.c
index 290a828d99..7748e8f1fd 100644
--- a/libavfilter/f_cue.c
+++ b/libavfilter/f_cue.c
@@ -26,6 +26,7 @@
 #include "avfilter.h"
 #include "filters.h"
 #include "internal.h"
+#include "video.h"
 
 typedef struct CueContext {
     const AVClass *class;
@@ -100,27 +101,13 @@ static const AVOption options[] = {
 AVFILTER_DEFINE_CLASS_EXT(cue_acue, "(a)cue", options);
 
 #if CONFIG_CUE_FILTER
-static const AVFilterPad cue_inputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_VIDEO,
-    },
-};
-
-static const AVFilterPad cue_outputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_VIDEO,
-    },
-};
-
 const AVFilter ff_vf_cue = {
     .name        = "cue",
     .description = NULL_IF_CONFIG_SMALL("Delay filtering to match a cue."),
     .priv_class  = &cue_acue_class,
     .priv_size   = sizeof(CueContext),
-    FILTER_INPUTS(cue_inputs),
-    FILTER_OUTPUTS(cue_outputs),
+    FILTER_INPUTS(ff_video_default_filterpad),
+    FILTER_OUTPUTS(ff_video_default_filterpad),
     .activate    = activate,
 };
 #endif /* CONFIG_CUE_FILTER */