libavfilter/vf_pad.c:278: error: Uninitialized Value
  The value read from bar_y was never initialized.

libavfilter/vf_pad.c:278:9: 
276.                        pad->line, pad->line_step, pad->hsub, pad->vsub,
277.                        0, bar_y, pad->w, bar_h);
278.         avfilter_draw_slice(link->dst->outputs[0], bar_y, bar_h, slice_dir);
             ^
279.     }
280. }
