libavdevice/v4l2.c:523: error: Uninitialized Value
  The value read from fps.num was never initialized.

libavdevice/v4l2.c:523:9: 
521.     }
522. 
523.     if (fps.num && fps.den) {
             ^
524.         av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
525.                fps.den, fps.num);
