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_acopy.c b/libavfilter/af_acopy.c
index 1591ec9639..f65f04d461 100644
--- a/libavfilter/af_acopy.c
+++ b/libavfilter/af_acopy.c
@@ -53,17 +53,10 @@ static const AVFilterPad acopy_inputs[] = {
     },
 };
 
-static const AVFilterPad acopy_outputs[] = {
-    {
-        .name = "default",
-        .type = AVMEDIA_TYPE_AUDIO,
-    },
-};
-
 const AVFilter ff_af_acopy = {
     .name          = "acopy",
     .description   = NULL_IF_CONFIG_SMALL("Copy the input audio unchanged to the output."),
     .flags         = AVFILTER_FLAG_METADATA_ONLY,
     FILTER_INPUTS(acopy_inputs),
-    FILTER_OUTPUTS(acopy_outputs),
+    FILTER_OUTPUTS(ff_audio_default_filterpad),
 };