t_track
t_track.start_track = l_ti.cdti_trk0;
t_track.start_index = l_ti.cdti_ind0;
t_track.end_track = l_ti.cdti_trk1;
t_track.end_index = l_ti.cdti_ind1;
error = ioctlf(fp, CDIOCPLAYTRACKS, &t_track);