expand            465 libavfilter/af_aiir.c         ret = expand(ctx, iir->ab[0], iir->nb_ab[0], botc);
expand            470 libavfilter/af_aiir.c         ret = expand(ctx, iir->ab[1], iir->nb_ab[1], topc);
expand            602 libavfilter/af_aiir.c             ret = expand(ctx, zeros, 2, b);
expand            606 libavfilter/af_aiir.c             ret = expand(ctx, poles, 2, a);