libavformat/mpegtsenc.c:600: error: Uninitialized Value
  The value read from buf[_] was never initialized.

libavformat/mpegtsenc.c:600:17: 
598.                 /* add stuffing */
599.                 memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);
600.                 buf[3] |= 0x20;
                     ^
601.                 buf[4] = stuffing_len - 1;
602.                 if (stuffing_len >= 2) {
