126 lines
2.6 KiB
C++
126 lines
2.6 KiB
C++
/*
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* © Copyright 2014 – Urheberrechtshinweis
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* Alle Rechte vorbehalten / All Rights Reserved
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*
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* Programmcode ist urheberrechtlich geschuetzt.
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* Das Urheberrecht liegt, soweit nicht ausdruecklich anders gekennzeichnet, bei Frank Ebner.
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* Keine Verwendung ohne explizite Genehmigung.
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* (vgl. § 106 ff UrhG / § 97 UrhG)
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*/
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#ifndef FIRREAL_H
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#define FIRREAL_H
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#include <vector>
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#include <cmath>
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#include <string>
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#include "../../../Assertions.h"
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namespace FIR {
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namespace Real {
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using Kernel = std::vector<float>;
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using DataVec = std::vector<float>;
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class Filter {
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Kernel kernel;
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DataVec data;
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public:
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/** ctor */
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Filter(const Kernel& kernel) : kernel(kernel) {
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;
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}
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/** empty ctor */
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Filter() : kernel() {
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;
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}
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/** set the filter-kernel */
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void setKernel(const Kernel& kernel) {
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this->kernel = kernel;
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}
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const Kernel& getKernel() const {
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return this->kernel;
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}
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void prefill(float val) {
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for (size_t i = 0; i < (kernel.size()-1)/2; ++i) {
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append(val);
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}
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}
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/** filter the given incoming real data */
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DataVec append(const DataVec& newData) {
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// append to local buffer (as we need some history)
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data.insert(data.end(), newData.begin(), newData.end());
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return processLocalBuffer();
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}
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/** filter the given incoming real value */
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float append(const float val) {
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data.push_back(val);
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auto tmp = processLocalBuffer();
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if (tmp.size() == 0) {return NAN;}
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if (tmp.size() == 1) {return tmp[0];}
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throw Exception("FIR::Real::Filter detected invalid result");
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}
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private:
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DataVec processLocalBuffer() {
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// sanity check
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Assert::isNot0(kernel.size(), "FIR::Real::Filter kernel not yet configured!");
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// number of processable elements (due to filter size)
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//const int processable = data.size() - kernel.size() + 1 - kernel.size()/2;
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const int processable = data.size() - kernel.size();
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// nothing to-do?
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if (processable <= 0) {return DataVec();}
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// result-vector
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DataVec res;
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res.resize(processable);
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// fire
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convolve(data.data(), res.data(), processable);
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// drop processed elements from the local buffer
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data.erase(data.begin(), data.begin() + processable);
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// done
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return res;
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}
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template <typename T> void convolve(const float* src, T* dst, const size_t cnt) {
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const size_t ks = kernel.size();
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for (size_t i = 0; i < cnt; ++i) {
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T t = T();
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for (size_t j = 0; j < ks; ++j) {
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t += src[j+i] * kernel[j];
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}
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if (t != t) {throw std::runtime_error("detected NaN");}
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dst[i] = t;
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}
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}
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};
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}
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}
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#endif // FIRREAL_H
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