avfilter/vsrc_mptestsrc: Store format in filter, remove query function

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavfilter/vsrc_mptestsrc.c

@@ -290,15 +290,6 @@ static int config_props(AVFilterLink *outlink)
     return 0;
 }
 
-static int query_formats(AVFilterContext *ctx)
-{
-    static const enum AVPixelFormat pix_fmts[] = {
-        AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE
-    };
-
-    return ff_set_common_formats_from_list(ctx, pix_fmts);
-}
-
 static int request_frame(AVFilterLink *outlink)
 {
     MPTestContext *test = outlink->src->priv;
@@ -361,5 +352,5 @@ const AVFilter ff_vsrc_mptestsrc = {
     .init          = init,
     .inputs        = NULL,
     FILTER_OUTPUTS(mptestsrc_outputs),
-    FILTER_QUERY_FUNC(query_formats),
+    FILTER_SINGLE_PIXFMT(AV_PIX_FMT_YUV420P),
 };