libavfilter/vf_pad.c:275: error: Uninitialized Value
  The value read from bar_y was never initialized.

libavfilter/vf_pad.c:275:9: 
273. 
274.     if (bar_h) {
275.         draw_rectangle(link->dst->outputs[0]->outpic,
             ^
276.                        pad->line, pad->line_step, pad->hsub, pad->vsub,
277.                        0, bar_y, pad->w, bar_h);
