$ ./vidthumb --help
Usage: ./vidthumb [OPTIONS] FILENAME

  -v, --verbose          Print verbose messages
  -d, --debug            Print debug messages
  -o, --output FILE      Write thumbnail to FILE
  -W, --width INT        Rescale the video to width
  -H, --height INT       Rescale the video to height
  -A, --ignore-aspect-ratio
                         Ignore aspect-ratio
  -p, --params PARAMS    Pass additional parameter to the thumbnailer (e.g. cols=5,rows=3)
  --fourd                Use fourd thumbnailer
                           parameter: slices=INT
  --grid                 Use grid thumbnailer (default)
                           parameter: cols=INT,rows=INT
  --directory            Use directory thumbnailer (default)
                           parameter: num=INT
  -t, --timeout SECONDS  Wait for SECONDS before giving up, -1 for infinity
  -T, --timestamp        Timestamp the frames
  -a, --accurate         Use accurate, but slow seeking