set_highshelf_rbj  285 libavfilter/af_aemphasis.c             set_highshelf_rbj(&s->rc[0].r1, cfreq, q, 1. / gain, sr);
set_highshelf_rbj  287 libavfilter/af_aemphasis.c             set_highshelf_rbj(&s->rc[0].r1, cfreq, q, gain, sr);