/* ======================================================================== */ /* */ /* TEXAS INSTRUMENTS, INC. */ /* */ /* NAME */ /* DSPF_sp_biquad: Biquad filter (IIR filter of 2nd order) */ /* */ /* USAGE */ /* This routine has following C prototype: */ /* */ /* void DSPF_sp_biquad(float *x, float *b, float *a, float *delay, */ /* float *r, int nx) */ /* */ /* x : Pointer to input samples */ /* b : Pointer to Nr coefs b0, b1, b2 */ /* a : Pointer to Dr coefs a1, a2 */ /* delay : Pointer to filter delays */ /* r : Pointer to output samples */ /* nx : Number of input/output samples */ /* */ /* DESCRIPTION */ /* This routine implements a DF 2 transposed structure of the biquad */ /* filter. The transfer function of a biquad can be written */ /* as: */ /* */ /* b(0) + b(1)z^(-1) + b(2)z^(-2) */ /* H(Z) = _________________________________ */ /* 1 + a(1)z^(-1) + a(2)z^(-2) */ /* */ /* ------------------------------------------------------------------------ */ /* Copyright (c) 2003 Texas Instruments, Incorporated. */ /* All Rights Reserved. */ /* ======================================================================== */ #ifndef DSPF_SP_BIQUAD_ #define DSPF_SP_BIQUAD_ 1 void DSPF_sp_biquad ( float x[], //Pointer to input samples float b[], //Pointer to numerator coefficients b[0], b[1] and b[2] float a[], //Pointer to denominator coefficients a[1] and a[2] float delay[], //Pointer to filter delays delay[0] and delay[1] float r[], //Pointer to output samples int nx //Number of input/output samples ); #endif /* ========================================================================*/ /* End of file: dspf_sp_biquad.h */ /* ------------------------------------------------------------------------*/ /* Copyright (c) 2003 Texas Instruments, Incorporated. */ /* All Rights Reserved. */ /* ========================================================================*/