libavcodec/vp8dsp.c:127: error: Uninitialized Value
  The value read from q0 was never initialized.

libavcodec/vp8dsp.c:127:5: 
125.     uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
126. 
127.     a = 3*(q0 - p0);
         ^
128. 
129.     if (is4tap)
