libavcodec/mss2.c:477: error: Uninitialized Value
  The value read from wmv9_mask was never initialized.

libavcodec/mss2.c:477:5: 
475. 
476.     Rectangle wmv9rects[MAX_WMV9_RECTANGLES], *r;
477.     int used_rects = 0, i, implicit_rect = 0, av_uninit(wmv9_mask);
         ^
478. 
479.     av_assert0(AV_INPUT_BUFFER_PADDING_SIZE >=
