ff_iir_filter_init_state  340 libavcodec/iirfilter.c     fstate  = ff_iir_filter_init_state(FILT_ORDER);
ff_iir_filter_init_state  100 libavcodec/iirfilter.h struct FFIIRFilterState* ff_iir_filter_init_state(int order);
ff_iir_filter_init_state  117 libavcodec/psymodel.c             ctx->fstate[i] = ff_iir_filter_init_state(FILT_ORDER);