libavcodec/vp9mvs.c:309: error: Uninitialized Value
  The value read from hp was never initialized.

libavcodec/vp9mvs.c:309:28: 
307.                 mv[0].y += read_mv_component(s, 0, hp);
308.             if (j & 1)
309.                 mv[0].x += read_mv_component(s, 1, hp);
                                ^
310.         }
311. 
