libavcodec/mss2.c:478: error: Uninitialized Value
  The value read from wmv9_mask was never initialized.

libavcodec/mss2.c:478:5: 
476. 
477.     Rectangle wmv9rects[MAX_WMV9_RECTANGLES], *r;
478.     int used_rects = 0, i, implicit_rect, av_uninit(wmv9_mask);
         ^
479. 
480.     av_assert0(FF_INPUT_BUFFER_PADDING_SIZE >=
