option "filter_num" f "point of filter chain to grab" int typestr="num" default="1" optional option "slot" s "only grab this slot; grab any slot if negative" int typestr="num" default="-1" optional option "audio_format" a "only grab this type of input stream; grab any if empty" string typestr="name" default="" optional option "input_grab" i "grab the filter input instead of its output" flag off option "one_shot" o "stop grabbing if audio file changes" flag off option "mode" m "select grab mode" typestr="grab_mode" values="sloppy","aggressive","pedantic" default="sloppy" optional