let gain0 = SIPRO_GAIN_CB_LBR[self.gc_index[sf]][0];
let gain1 = SIPRO_GAIN_CB_LBR[self.gc_index[sf]][1];
self.prev_pitch_gain = gain0;
let gain0 = SIPRO_GAIN_CB_LBR[self.gc_index[sf]][0];
let gain1 = SIPRO_GAIN_CB_LBR[self.gc_index[sf]][1];
self.prev_pitch_gain = gain0;