libavformat/flvdec.c:890: error: Uninitialized Value
  The value read from size was never initialized.

libavformat/flvdec.c:890:11: 
888.     }
889. 
890.     ret = av_get_packet(s->pb, pkt, size);
               ^
891.     if (ret < 0)
892.         return AVERROR(EIO);
