Function avfilter_graph_send_command 

pub unsafe fn avfilter_graph_send_command(
    _graph: *mut AVFilterGraph,
    _target: *const c_char,
    _cmd: *const c_char,
    _arg: *const c_char,
    _res: *mut c_char,
    _res_len: c_int,
    _flags: c_int,
) -> c_int