| /******************************************************************** |
| * * |
| * THIS FILE IS PART OF THE Ogg Vorbis SOFTWARE CODEC SOURCE CODE. * |
| * USE, DISTRIBUTION AND REPRODUCTION OF THIS SOURCE IS GOVERNED BY * |
| * THE GNU PUBLIC LICENSE 2, WHICH IS INCLUDED WITH THIS SOURCE. * |
| * PLEASE READ THESE TERMS DISTRIBUTING. * |
| * * |
| * THE OggSQUISH SOURCE CODE IS (C) COPYRIGHT 1994-2000 * |
| * by Monty <monty@xiph.org> and The XIPHOPHORUS Company * |
| * http://www.xiph.org/ * |
| * * |
| ******************************************************************** |
| |
| function: Direct Form I, II IIR filters, plus some specializations |
| last mod: $Id$ |
| |
| ********************************************************************/ |
| |
| #ifndef _V_IIR_H_ |
| #define _V_IIR_H_ |
| |
| typedef struct { |
| int stages; |
| double *coeff_A; |
| double *coeff_B; |
| double *z_A; |
| double *z_B; |
| int ring; |
| double gain; |
| } IIR_state; |
| |
| void IIR_init(IIR_state *s,int stages,double gain, double *A, double *B); |
| void IIR_clear(IIR_state *s); |
| double IIR_filter(IIR_state *s,double in); |
| double IIR_filter_ChebBand(IIR_state *s,double in); |
| |
| #endif |
