Function ncdirectf_from_file 

pub unsafe extern "C" fn ncdirectf_from_file(
    n: *mut ncdirect,
    filename: *const c_char,
) -> *mut ncdirectf

Load media from disk, but do not yet render it (presumably because you want to get its geometry via ncdirectf_geom(), or to use the same file with ncdirect_render_loaded_frame() multiple times). You must destroy the result with ncdirectf_free();