lavfi/af_pan: convert to query_func2()

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

libavfilter/af_pan.c

@@ -243,31 +243,24 @@ fail:
     return ret;
 }
 
-static int query_formats(AVFilterContext *ctx)
+static int query_formats(const AVFilterContext *ctx,
+                         AVFilterFormatsConfig **cfg_in,
+                         AVFilterFormatsConfig **cfg_out)
 {
     const PanContext *pan = ctx->priv;
-    AVFilterLink *inlink  = ctx->inputs[0];
-    AVFilterLink *outlink = ctx->outputs[0];
     AVFilterChannelLayouts *layouts;
     int ret;
 
-    /* libswr supports any sample and packing formats */
-    if ((ret = ff_set_common_formats(ctx, ff_all_formats(AVMEDIA_TYPE_AUDIO))) < 0)
-        return ret;
-
-    if ((ret = ff_set_common_all_samplerates(ctx)) < 0)
-        return ret;
-
     // inlink supports any channel layout
     layouts = ff_all_channel_counts();
-    if ((ret = ff_channel_layouts_ref(layouts, &inlink->outcfg.channel_layouts)) < 0)
+    if ((ret = ff_channel_layouts_ref(layouts, &cfg_in[0]->channel_layouts)) < 0)
         return ret;
 
     // outlink supports only requested output channel layout
     layouts = NULL;
     if ((ret = ff_add_channel_layout(&layouts, &pan->out_channel_layout)) < 0)
         return ret;
-    return ff_channel_layouts_ref(layouts, &outlink->incfg.channel_layouts);
+    return ff_channel_layouts_ref(layouts, &cfg_out[0]->channel_layouts);
 }
 
 static int config_props(AVFilterLink *link)
@@ -432,5 +425,5 @@ const AVFilter ff_af_pan = {
     .uninit        = uninit,
     FILTER_INPUTS(pan_inputs),
     FILTER_OUTPUTS(ff_audio_default_filterpad),
-    FILTER_QUERY_FUNC(query_formats),
+    FILTER_QUERY_FUNC2(query_formats),
 };