lavfi/avf_showfreqs: switch to query_func2()

Also, drop redundant calls that also happen implicitly in generic code.

libavfilter/avf_showfreqs.c

@@ -116,32 +116,23 @@ static const AVOption showfreqs_options[] = {
 
 AVFILTER_DEFINE_CLASS(showfreqs);
 
-static int query_formats(AVFilterContext *ctx)
+static int query_formats(const AVFilterContext *ctx,
+                         AVFilterFormatsConfig **cfg_in,
+                         AVFilterFormatsConfig **cfg_out)
 {
     AVFilterFormats *formats = NULL;
-    AVFilterChannelLayouts *layouts = NULL;
-    AVFilterLink *inlink = ctx->inputs[0];
-    AVFilterLink *outlink = ctx->outputs[0];
     static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE };
     static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE };
     int ret;
 
     /* set input audio formats */
     formats = ff_make_format_list(sample_fmts);
-    if ((ret = ff_formats_ref(formats, &inlink->outcfg.formats)) < 0)
-        return ret;
-
-    layouts = ff_all_channel_counts();
-    if ((ret = ff_channel_layouts_ref(layouts, &inlink->outcfg.channel_layouts)) < 0)
-        return ret;
-
-    formats = ff_all_samplerates();
-    if ((ret = ff_formats_ref(formats, &inlink->outcfg.samplerates)) < 0)
+    if ((ret = ff_formats_ref(formats, &cfg_in[0]->formats)) < 0)
         return ret;
 
     /* set output video format */
     formats = ff_make_format_list(pix_fmts);
-    if ((ret = ff_formats_ref(formats, &outlink->incfg.formats)) < 0)
+    if ((ret = ff_formats_ref(formats, &cfg_out[0]->formats)) < 0)
         return ret;
 
     return 0;
@@ -566,6 +557,6 @@ const AVFilter ff_avf_showfreqs = {
     .activate      = activate,
     FILTER_INPUTS(ff_audio_default_filterpad),
     FILTER_OUTPUTS(showfreqs_outputs),
-    FILTER_QUERY_FUNC(query_formats),
+    FILTER_QUERY_FUNC2(query_formats),
     .priv_class    = &showfreqs_class,
 };