libavformat/utils.c:1832: error: Uninitialized Value
  The value read from start_time[_] was never initialized.

libavformat/utils.c:1832:13: 
1830.             start_time[pkt->stream_index] != AV_NOPTS_VALUE) {
1831.             end_time = pkt->pts;
1832.             duration = end_time - start_time[pkt->stream_index];
                  ^
1833.             if (duration < 0)
1834.                 duration += 1LL<<st->pts_wrap_bits;
