libavcodec/fmvc.c:229: error: Uninitialized Value
  The value read from opcode was never initialized.

libavcodec/fmvc.c:229:13: 
227.             bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
228.             bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
229.             len = opcode & 3;
                 ^
230.             if (!len) {
231.                 repeat = 1;
