Add a media's input MRL. This will add the specified one.
        @param psz_name: the media to work on.
        @param psz_input: the input MRL.
        @return: 0 on success, -1 on error.

def vlm_add_input(self, psz_name, psz_input):
        '''Add a media's input MRL. This will add the specified one.
        @param psz_name: the media to work on.
        @param psz_input: the input MRL.
        @return: 0 on success, -1 on error.
        '''
        return libvlc_vlm_add_input(self, str_to_bytes(psz_name), str_to_bytes(psz_input))