谁帮我写一个基于DSP的小波滤波算法的程序

参考代码：

/* Simple implementation of Biquad filters -- Tom St Denis

*

* Based on the work

Cookbook formulae for audio EQ biquad filter coefficients

---------------------------------------------------------

by Robert Bristow-Johnson, pbjrbj@viconet.com a.k.a. robert@audioheads.com

* Available on the web at

http://www.smartelectronix.com/musicdsp/text/filters005.txt

* Enjoy.

*

* This work is hereby placed in the public domain for all purposes, whether

* commercial, free [as in speech] or educational, etc. Use the code and please

* give me credit if you wish.

*

* Tom St Denis -- http://tomstdenis.home.dhs.org

*/

/* this would be biquad.h */

#include <math.h>

#include <stdlib.h>

#ifndef M_LN2

#define M_LN20.69314718055994530942

#endif

#ifndef M_PI

#define M_PI 3.14159265358979323846

#endif

/* whatever sample type you want */

typedef double smp_type

/* this holds the data required to update samples thru a filter */

typedef struct {

smp_type a0, a1, a2, a3, a4

smp_type x1, x2, y1, y2

}

biquad

extern smp_type BiQuad(smp_type sample, biquad * b)

extern biquad *BiQuad_new(int type, smp_type dbGain, /* gain of filter */

smp_type freq, /* center frequency */

smp_type srate,/* sampling rate */

smp_type bandwidth) /型迅* bandwidth in octaves */

/* filter types */裤穗

enum {

LPF, /* low pass filter */

HPF, /* High pass filter */

BPF, /* band pass filter */

NOTCH, /* Notch Filter */

PEQ, /胡租卜* Peaking band EQ filter */

LSH, /* Low shelf filter */

HSH /* High shelf filter */

}

/* Below this would be biquad.c */

/* Computes a BiQuad filter on a sample */

smp_type BiQuad(smp_type sample, biquad * b)

{

smp_type result

/* compute result */

result = b->a0 * sample + b->a1 * b->x1 + b->a2 * b->x2 -

b->a3 * b->y1 - b->a4 * b->y2

/* shift x1 to x2, sample to x1 */

b->x2 = b->x1

b->x1 = sample

/* shift y1 to y2, result to y1 */

b->y2 = b->y1

b->y1 = result

return result

}

/* sets up a BiQuad Filter */

biquad *BiQuad_new(int type, smp_type dbGain, smp_type freq,

smp_type srate, smp_type bandwidth)

{

biquad *b

smp_type A, omega, sn, cs, alpha, beta

smp_type a0, a1, a2, b0, b1, b2

b = malloc(sizeof(biquad))

if (b == NULL)

return NULL

/* setup variables */

A = pow(10, dbGain /40)

omega = 2 * M_PI * freq /srate

sn = sin(omega)

cs = cos(omega)

alpha = sn * sinh(M_LN2 /2 * bandwidth * omega /sn)

beta = sqrt(A + A)

switch (type) {

case LPF:

b0 = (1 - cs) /2

b1 = 1 - cs

b2 = (1 - cs) /2

a0 = 1 + alpha

a1 = -2 * cs

a2 = 1 - alpha

break

case HPF:

b0 = (1 + cs) /2

b1 = -(1 + cs)

b2 = (1 + cs) /2

a0 = 1 + alpha

a1 = -2 * cs

a2 = 1 - alpha

break

case BPF:

b0 = alpha

b1 = 0

b2 = -alpha

a0 = 1 + alpha

a1 = -2 * cs

a2 = 1 - alpha

break

case NOTCH:

b0 = 1

b1 = -2 * cs

b2 = 1

a0 = 1 + alpha

a1 = -2 * cs

a2 = 1 - alpha

break

case PEQ:

b0 = 1 + (alpha * A)

b1 = -2 * cs

b2 = 1 - (alpha * A)

a0 = 1 + (alpha /A)

a1 = -2 * cs

a2 = 1 - (alpha /A)

break

case LSH:

b0 = A * ((A + 1) - (A - 1) * cs + beta * sn)

b1 = 2 * A * ((A - 1) - (A + 1) * cs)

b2 = A * ((A + 1) - (A - 1) * cs - beta * sn)

a0 = (A + 1) + (A - 1) * cs + beta * sn

a1 = -2 * ((A - 1) + (A + 1) * cs)

a2 = (A + 1) + (A - 1) * cs - beta * sn

break

case HSH:

b0 = A * ((A + 1) + (A - 1) * cs + beta * sn)

b1 = -2 * A * ((A - 1) + (A + 1) * cs)

b2 = A * ((A + 1) + (A - 1) * cs - beta * sn)

a0 = (A + 1) - (A - 1) * cs + beta * sn

a1 = 2 * ((A - 1) - (A + 1) * cs)

a2 = (A + 1) - (A - 1) * cs - beta * sn

break

default:

free(b)

return NULL

}

/* precompute the coefficients */

b->a0 = b0 /a0

b->a1 = b1 /a0

b->a2 = b2 /a0

b->a3 = a1 /a0

b->a4 = a2 /a0

/* zero initial samples */

b->x1 = b->x2 = 0

b->y1 = b->y2 = 0

return b

}

/* crc==3062280887, version==4, Sat Jul 7 00:03:23 2001 */

仿真用matlab啊，小波变换什么的直接用matlab的库函数就行。DSP和FPGA看你用的什么芯片了拍磨，TI 的DSP就是CCS，ADI的DSP就是Vitual DSP++，Altera的FPGA就是quartus，Xilinx的袭歼斗就是改困ISE

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