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, 16 deletions

diff --git a/libavfilter/vf_null.c b/libavfilter/vf_null.c
index fa80e2a102..1502774f98 100644
--- a/libavfilter/vf_null.c
+++ b/libavfilter/vf_null.c
@@ -26,24 +26,10 @@
 #include "internal.h"
 #include "video.h"
 
-static const AVFilterPad avfilter_vf_null_inputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_VIDEO,
-    },
-};
-
-static const AVFilterPad avfilter_vf_null_outputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_VIDEO,
-    },
-};
-
 const AVFilter ff_vf_null = {
     .name        = "null",
     .description = NULL_IF_CONFIG_SMALL("Pass the source unchanged to the output."),
     .flags       = AVFILTER_FLAG_METADATA_ONLY,
-    FILTER_INPUTS(avfilter_vf_null_inputs),
-    FILTER_OUTPUTS(avfilter_vf_null_outputs),
+    FILTER_INPUTS(ff_video_default_filterpad),
+    FILTER_OUTPUTS(ff_video_default_filterpad),
 };