lavfi/afade: switch to AVOption-base system

doc/filters.texi

@@ -610,9 +610,6 @@ Beware of clipping when using a positive gain.
 
 Apply fade-in/out effect to input audio.
 
-The filter accepts parameters as a list of @var{key}=@var{value}
-pairs, separated by ":".
-
 A description of the accepted parameters follows.
 
 @table @option

libavfilter/af_afade.c

@@ -288,8 +288,6 @@ static const AVFilterPad avfilter_af_afade_outputs[] = {
     { NULL }
 };
 
-static const char *const shorthand[] = { NULL };
-
 AVFilter avfilter_af_afade = {
     .name          = "afade",
     .description   = NULL_IF_CONFIG_SMALL("Fade in/out input audio."),
@@ -299,5 +297,4 @@ AVFilter avfilter_af_afade = {
     .inputs        = avfilter_af_afade_inputs,
     .outputs       = avfilter_af_afade_outputs,
     .priv_class    = &afade_class,
-    .shorthand     = shorthand,
 };

libavfilter/avfilter.c

@@ -656,6 +656,7 @@ int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque
     AVDictionaryEntry *e;
     int ret=0;
     int anton_options =
+        !strcmp(filter->filter->name,  "afade"     ) ||
         !strcmp(filter->filter->name,  "aformat") ||
         !strcmp(filter->filter->name,  "ass")     ||
         !strcmp(filter->filter->name,  "blackframe") ||