get_band_noise 691 libavfilter/af_afftdn.c dnch->band_noise[i] = get_band_noise(s, i, 50.0, 500.5, 2125.0) + FFMAX(i - 7, 0); get_band_noise 695 libavfilter/af_afftdn.c dnch->band_noise[i] = get_band_noise(s, i, 1.0, 500.0, 1.0E10) + FFMAX(i - 12, -5);