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/*
* DFTProcessor.cpp
*
* Created on: 29.04.2011
* Author: sven
*/
#ifndef DFTPROCESSOR_H_
#include "DFTProcessor.h"
#endif
#ifndef _GLIBCXX_IOSTREAM
#include <iostream>
#endif
#ifndef _GLIBCXX_FSTREAM
#include <fstream>
#endif
#include <cmath>
#include <string.h>
#include <stdlib.h>
#include <iomanip>
const double PI = 3.14159265358979323846264338327950288419716939;
const char* ORIG_FILENAME = "orig.wav";
const char* IDFT_FILENAME = "idft.wav";
DFTProcessor::DFTProcessor(DFTAppParameters& params)
:mParams(params)
,mNumDftSamples(mParams.getNumSamples() / 2)
,mInputData(mParams.getNumSamples())
,mRe(mNumDftSamples)
,mIm(mNumDftSamples)
,mIdft(mParams.getNumSamples())
{
std::cout << "DFT processing " << mParams.getNumSamples() <<
" samples of" << mParams.getInputFilename() << std::endl;
std::ifstream inFile;
std::ofstream origFile;
std::ofstream idftFile;
inFile.open(mParams.getInputFilename().c_str(), std::ios::in | std::ios::binary);
origFile.open(ORIG_FILENAME, std::ios::out | std::ios::binary);
idftFile.open(IDFT_FILENAME, std::ios::out | std::ios::binary);
int dataStartOffset = 0x2C;
char header[dataStartOffset];
inFile.read(&header[0],dataStartOffset);
memcpy(&mSampleRate,((&header[0])+0x18),4);
origFile.write((char*) &header[0],dataStartOffset);
idftFile.write((char*) &header[0],dataStartOffset);
short data;
std::cout << "Original file:" << std::endl;
for (unsigned i=0;i<mParams.getNumSamples();i++)
{
inFile.read((char*) &data,sizeof(short));
mInputData.at(i) = (double) data;
origFile.write((char*) &data, sizeof(short));
if (i < 5) {
if (i != 0) {
std::cout << std::endl;
}
std::cout << mInputData.at(i);
}
}
inFile.close();
origFile.close();
double nd,id,Nd,xn;
Nd = (double) mParams.getNumSamples();
for (unsigned i = 0; i < mNumDftSamples; i++) {
id = (double) i;
mRe.at(i) = 0.0;
mIm.at(i) = 0.0;
for (unsigned n=0; n < mParams.getNumSamples(); n++) {
nd = (double) n;
xn = mInputData.at(n);
mRe.at(i) += xn * std::cos(2.0 * PI * nd * id / Nd );
mIm.at(i) += xn * std::sin(2.0 * PI * nd * id / Nd );
}
mIm.at(i) = -mIm.at(i);
}
std::cout << std::endl << "dft done" << std::endl;
// idft
double rex,imx,fd;
std::cout << "idft file:" << std::endl;
for (unsigned n=0 ; n<mParams.getNumSamples() ; n++)
{
nd = (double) n;
double reSum = 0.0;
double imSum = 0.0;
for (unsigned f=0; f < mNumDftSamples; f++)
{
fd = (double) f;
if (f == 0) {
rex = mRe.at(0) / Nd;
} else if (f == mNumDftSamples) {
rex = mRe.at(mNumDftSamples) / Nd;
} else {
rex = mRe.at(f) / (Nd / 2.0);
}
imx = - mIm.at(f) / (Nd / 2.0);
reSum += rex * std::cos(2.0 * PI * nd * fd / Nd);
imSum += imx * std::sin(2.0 * PI * nd * fd / Nd);
}
mIdft.at(n) = reSum + imSum;
}
for (unsigned n=0 ; n<mParams.getNumSamples(); n++) {
data = (short) round(mIdft.at(n));
idftFile.write((char*) &data, sizeof(short));
if (n < 5) {
if (n != 0) {
std::cout << std::endl;
}
double dout = mIdft.at(n);
std::cout << std::setprecision(16) << dout;
}
}
idftFile.close();
std::cout << std::endl << "idft done" << std::endl;
// amplitude spectrum
double A1, A2;
unsigned maxTimeDomFreq = mSampleRate / 2;
unsigned freqIntervalWidth = maxTimeDomFreq / mNumDftSamples;
for (unsigned f = 0 ; f < mNumDftSamples ; f++) {
A1 = mIm.at(f);
A2 = mRe.at(f);
SpectralData actSpecData;
actSpecData.mAmplitude = std::sqrt( (A1*A1) + (A2*A2) );
actSpecData.mPhase = std::atan(A2/A1);
actSpecData.mFreq = f * freqIntervalWidth;
mSpectrum.push_back(actSpecData);
}
writeSpectrumToCSV();
startGnuPlot();
}
DFTProcessor::~DFTProcessor() {
// TODO Auto-generated destructor stub
}
void DFTProcessor::writeSpectrumToCSV()
{
std::ofstream csvFile;
csvFile.open("spectrum.csv", std::ios::out);
std::vector<SpectralData>::const_iterator specIter;
for(specIter = mSpectrum.begin() ; specIter != mSpectrum.end() ; specIter++) {
const SpectralData& actSpec = *specIter;
if (specIter != mSpectrum.begin()) {
csvFile << std::endl;
}
csvFile << actSpec.mFreq << ";";
csvFile << std::setprecision (12) << std::fixed << actSpec.mAmplitude;
csvFile << ";";
csvFile << std::setprecision (12) << std::fixed << actSpec.mPhase;
}
csvFile.close();
}
void DFTProcessor::startGnuPlot()
{
int i = system("gnuplot spectrum.plt -p");
if (i != 0) {
std::cerr << "Error starting gnuplot: " << i << std::endl;
}
}
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