FF_FILTER_TYPE_BUTTERWORTH  182 libavcodec/iirfilter.c     case FF_FILTER_TYPE_BUTTERWORTH:
FF_FILTER_TYPE_BUTTERWORTH  337 libavcodec/iirfilter.c     fcoeffs = ff_iir_filter_init_coeffs(NULL, FF_FILTER_TYPE_BUTTERWORTH,
FF_FILTER_TYPE_BUTTERWORTH  111 libavcodec/psymodel.c     ctx->fcoeffs = ff_iir_filter_init_coeffs(avctx, FF_FILTER_TYPE_BUTTERWORTH,