'Get vlm_media instance position by name or instance id.
@param psz_name: name of vlm media instance.
@param i_instance: instance id.
@return: position as float or -1. on error.'

def vlm_get_media_instance_position(self, psz_name, i_instance):

    return libvlc_vlm_get_media_instance_position(self, str_to_bytes(psz_name), i_instance)
