avfilter/geq: assert on pixel format descriptor

inlink->format is supposed to be set to a valid format controlled by query_formats().

libavfilter/vf_geq.c

@@ -26,6 +26,7 @@
  * ported by Clément Bœsch for FFmpeg.
  */
 
+#include "libavutil/avassert.h"
 #include "libavutil/avstring.h"
 #include "libavutil/eval.h"
 #include "libavutil/opt.h"
@@ -192,6 +193,8 @@ static int geq_config_props(AVFilterLink *inlink)
     GEQContext *geq = inlink->dst->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
 
+    av_assert0(desc);
+
     geq->hsub = desc->log2_chroma_w;
     geq->vsub = desc->log2_chroma_h;
     geq->planes = desc->nb_components;