Function vaQueryConfigEntrypoints 

pub unsafe extern "C" fn vaQueryConfigEntrypoints(
    dpy: VADisplay,
    profile: Type,
    entrypoint_list: *mut Type,
    num_entrypoints: *mut c_int,
) -> VAStatus

Query supported entrypoints for a given profile The caller must provide an “entrypoint_list” array that can hold at least vaMaxNumEntrypoints() entries. The actual number of entrypoints returned in “entrypoint_list” is returned in “num_entrypoints”.