residual_filter   597 libavcodec/evrcdec.c     residual_filter(&e->postfilter_residual[ACB_SIZE], scratch, wcoef1, e->postfilter_fir, length);
residual_filter   541 libavcodec/g729postfilter.c     residual_filter(residual + RES_PREV_DATA_SIZE, lp_gn + 11, speech, subframe_size);