@@ -187,7 +187,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)

         stats[plane] /= s->planewidth[plane] * s->planeheight[plane];

         snprintf(key, sizeof(key), "lavfi.bitplanenoise.%d.%d", plane, s->bitplane);

-        snprintf(metabuf, sizeof(metabuf), "%f", 1. - 2.* fabsf((stats[plane] - 0.5)));

+        snprintf(metabuf, sizeof(metabuf), "%f", 1. - 2.* fabs((stats[plane] - 0.5)));

         av_dict_set(&out->metadata, key, metabuf, 0);

     }