ProcessFloatSamples.h

/*
*   File:       ProcessFloatSamples.h
*
*   Contains:   This file provides the interface to a simple filter that implements a lowpass filter with with a 400 Hz cutoff.  
*               Good references for the implementation of filters include:
*                -Discrete-Time Signal Processing, Schafer
*                -Introduction to Signal Processing, Orfanidis
*                -Understanding Digital Signal Processing, Lyons
*   
*   Version:    1.0
*
*   Created:    11-23-2004
*
*   � Copyright 2004-2013 Apple Computer, Inc. All rights reserved.
*
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#include <IOKit/IOTypes.h>
 
// _ParamStruct - coefficients for filter
 
__BEGIN_DECLS
 
typedef struct _ParamStruct 
{
    float       b0;
    float       b1;
    float       b2;
    float       a1;
    float       a2;
} ParamStruct, *ParamStructPtr;
 
// _StateStruct - state variables for filter
 
typedef struct _StateStruct 
{
    float       xstate1l;
    float       xstate2l;
    float       ystate1l;
    float       ystate2l;
    float       xstate1r;
    float       xstate2r;
    float       ystate1r;
    float       ystate2r;
} StateStruct, *StateStructPtr;
 
void processSamples (float * dataBuffer, UInt32 numSampleFrames, UInt32 numChannels, ParamStructPtr inParamStructPtr, StateStructPtr inStateStructPtr);
void resetProcessingState (StateStructPtr inStateStructPtr);
void setProcessingParameters (ParamStructPtr inParamStructPtr, UInt32 inSampleRate, UInt32 inNumChannels);
 
__END_DECLS