avfilter: Deduplicate default audio inputs/outputs

Lots of audio filters use very simple inputs or outputs:
An array with a single AVFilterPad whose name is "default"
and whose type is AVMEDIA_TYPE_AUDIO; 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 (4784B here) as well as relocations.

*: In fact, several filters (like the filters in af_biquads.c)
already use the same inputs; 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/af_tremolo.c b/libavfilter/af_tremolo.c
index 3e3e2be6f8..024c402b79 100644
--- a/libavfilter/af_tremolo.c
+++ b/libavfilter/af_tremolo.c
@@ -121,13 +121,6 @@ static const AVFilterPad avfilter_af_tremolo_inputs[] = {
     },
 };
 
-static const AVFilterPad avfilter_af_tremolo_outputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_AUDIO,
-    },
-};
-
 const AVFilter ff_af_tremolo = {
     .name          = "tremolo",
     .description   = NULL_IF_CONFIG_SMALL("Apply tremolo effect."),
@@ -135,7 +128,7 @@ const AVFilter ff_af_tremolo = {
     .priv_class    = &tremolo_class,
     .uninit        = uninit,
     FILTER_INPUTS(avfilter_af_tremolo_inputs),
-    FILTER_OUTPUTS(avfilter_af_tremolo_outputs),
+    FILTER_OUTPUTS(ff_audio_default_filterpad),
     FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_DBL),
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
 };