option "loglevel" l "set loglevel (0-6)" int typestr="level" default="4" optional option "filter" f "Specify filter. May be given multiple times to 'pipe' the stream through arbitrary many filters in an efficient way. The same filter may appear more than once, order matters. Filter options may be specified for each '-f' option separately. Note that you will have to quote these options like this: -f 'compress --inertia 5 --damp 2' " string typestr="filter_spec" optional multiple option "list_filters" L "print list of available filters and exit" flag off