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/vf_codecview.c b/libavfilter/vf_codecview.c
index cddb3e5368..0c1ef21e28 100644
--- a/libavfilter/vf_codecview.c
+++ b/libavfilter/vf_codecview.c
@@ -36,6 +36,7 @@
 #include "avfilter.h"
 #include "qp_table.h"
 #include "internal.h"
+#include "video.h"
 
 #define MV_P_FOR  (1<<0)
 #define MV_B_FOR  (1<<1)
@@ -334,19 +335,12 @@ static const AVFilterPad codecview_inputs[] = {
     },
 };
 
-static const AVFilterPad codecview_outputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_VIDEO,
-    },
-};
-
 const AVFilter ff_vf_codecview = {
     .name          = "codecview",
     .description   = NULL_IF_CONFIG_SMALL("Visualize information about some codecs."),
     .priv_size     = sizeof(CodecViewContext),
     FILTER_INPUTS(codecview_inputs),
-    FILTER_OUTPUTS(codecview_outputs),
+    FILTER_OUTPUTS(ff_video_default_filterpad),
     // TODO: we can probably add way more pixel formats without any other
     // changes; anything with 8-bit luma in first plane should be working
     FILTER_SINGLE_PIXFMT(AV_PIX_FMT_YUV420P),