IIR_CH            175 libavfilter/af_aiir.c IIR_CH(s32p, int32_t, INT32_MIN, INT32_MAX, 1)
IIR_CH            176 libavfilter/af_aiir.c IIR_CH(fltp, float,         -1.,        1., 0)
IIR_CH            177 libavfilter/af_aiir.c IIR_CH(dblp, double,        -1.,        1., 0)