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00039 #ifndef _VrIIRFILTER_H_
00040 #define _VrIIRFILTER_H_
00041
00042 #include <VrSigProc.h>
00043
00044 template<class iType,class oType>
00045 class VrIIRfilter : public VrSigProc {
00046 protected:
00047 int order,offset;
00048 double *Btaps, *Ataps;
00049 iType *input_hist;
00050 oType *output_hist;
00051 float gain;
00052
00053 public:
00054 virtual int work(VrSampleRange output, void *ao[],
00055 VrSampleRange inputs[], void *ai[]);
00056 virtual void initialize();
00057 VrIIRfilter(int,double *, double *, float);
00058 ~VrIIRfilter();
00059 };
00060
00061 template<class iType,class oType> int
00062 VrIIRfilter<iType,oType>::work(VrSampleRange output, void *ao[],
00063 VrSampleRange inputs[], void *ai[])
00064 {
00065 oType result;
00066 for (unsigned int sample=0;sample<output.size;sample++)
00067 {
00068 input_hist[(sample + offset)% order] = ((iType **)ai)[0][sample];
00069 result = Btaps[0] * ((iType **)ai)[0][sample];
00070
00071 for (int tap=1; tap < order; tap++)
00072 result += (Btaps[tap] * input_hist[(sample + offset + order - tap)%order])
00073 + (Ataps[tap] * output_hist[(sample + offset + order - tap)%order]);
00074 ((oType **)ao)[0][sample] = gain * result;
00075 output_hist[(sample + offset) % order] = result;
00076 }
00077 offset = (offset + output.size) % order;
00078 return output.size;
00079 }
00080
00081
00082 template<class iType,class oType>
00083 VrIIRfilter<iType,oType>::VrIIRfilter(int ord, double *intaps, double *outtaps, float gain)
00084 :VrSigProc(1, sizeof(iType), sizeof(oType)), order(ord),offset(0),gain(gain)
00085 {
00086 Ataps = new double[order];
00087 Btaps = new double[order];
00088 input_hist = new iType[order];
00089 output_hist = new oType[order];
00090
00091 for(int i = 0; i<order; i++)
00092 {
00093 input_hist[i] = 0; output_hist[i] = 0;
00094 Btaps[i] = intaps[i];
00095 Ataps[i] = outtaps[i];
00096 }
00097 }
00098
00099 template<class iType,class oType>
00100 void VrIIRfilter<iType,oType>::initialize()
00101 {
00102
00103
00104 }
00105
00106 template<class iType,class oType>
00107 VrIIRfilter<iType,oType>::~VrIIRfilter()
00108 {
00109 delete Ataps;
00110 delete Btaps;
00111 delete input_hist;
00112 delete output_hist;
00113 }
00114
00115 #endif
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