libavformat/utils.c:1927: error: Uninitialized Value
  The value read from last_dts[_] was never initialized.

libavformat/utils.c:1927:13: 
1925.         {
1926.             int index= pkt->stream_index;
1927.             int64_t last= last_dts[index];
                  ^
1928.             int64_t duration= pkt->dts - last;
1929. 
