amf_biquadcascade.h

ADI SHARC DSP 音频算法标准模块库

#ifndef _AMF_BIQUADCASCADE_
#define _AMF_BIQUADCASCADE_

// Copyright(c) 2005 Analog Devices, Inc. All Rights Reserved.
// This software is proprietary and confidential to Analog Devices, Inc. and its licensors.

// File    : $Id: //depot/development/visualaudio/modules/2.5.0/SHARC/Include/AMF_BiquadCascade.h#3 $ 
// Part of : VisualAudio V2.5.0 
// Updated : $Date: 2006/10/12 $ by $Author: Fernando $




#include "AudioProcessing.h"

#ifdef __ECC__

// C declarations

typedef struct {
    AMF_Module b;
    
    // Parameters:
    int numSections; // number of Biquads (must be even?)
    float totalAmp;  // totalAmp = product of all stage n0 coefs.
                     // Numerator coefs in the following array must be
                     // scaled accordingly.
    float pm *coefs;
    /*
    coef layout:
    filter1 d2    (2nd-delayed denominator coef, negated)
     filter2 d2    (2nd-delayed denominator coef, negated)
     filter1 d1    (1st-delayed denominator coef, negated)
     filter2 d1    (1st-delayed denominator coef, negated)
     filter1 n2    (2nd-delayed numerator coef)
     filter2 n2    (2nd-delayed numerator coef)
     filter1 n1    (1st-delayed numerator coef)
     filter2 n1    (1st-delayed numerator coef)
    filter3 d2    (2nd-delayed denominator coef, negated)
     filter4 d2    (2nd-delayed denominator coef, negated)
     filter3 d1    (1st-delayed denominator coef, negated)
     filter4 d1    (1st-delayed denominator coef, negated)
    etc...
    */
    
    // State:
    float lastIn;            // last input of previous tick (because this filter has 1 sample of delay)
    float *state;
} AMF_BiquadCascade;

extern const AMF_ModuleClass AMFClassBiquadCascade;

#else

// ASM declarations for offsets from start of instance (must be kept in synch with C version)
#define AMF_BiquadCascade_NumSections    AMF_Module_SIZE  // defined in AudioProcessing.h
#define AMF_BiquadCascade_TotalAmp    (AMF_Module_SIZE+1)  // defined in AudioProcessing.h
#define AMF_BiquadCascade_Coefs     (AMF_Module_SIZE+2)  // defined in AudioProcessing.h
#define AMF_BiquadCascade_LastIn     (AMF_Module_SIZE+3)
#define AMF_BiquadCascade_State     (AMF_Module_SIZE+4)

#endif

#endif