libavformat/mxg.c:115: error: Uninitialized Value
  The value read from soi_pos was never initialized.

libavformat/mxg.c:115:23: 
113.         return AVERROR(ENOMEM);
114.     mxg->buffer_ptr = mxg->buffer + current_pos;
115.     if (mxg->soi_ptr) mxg->soi_ptr = mxg->buffer + soi_pos;
                           ^
116. 
117.     /* get data */
