Mercurial > hg > vamp-tempogram
view FIRFilter.cpp @ 13:7680cc4c0073
* Tidying - made length of array variables type size_t and for loops unsigned int, where index > 0.
* Window length parameter is now a dropdown box.
author | Carl Bussey <c.bussey@se10.qmul.ac.uk> |
---|---|
date | Wed, 13 Aug 2014 14:18:00 +0100 |
parents | 17a260410116 |
children | c11367df624d |
line wrap: on
line source
// // FIRFilter.cpp // Tempogram // // Created by Carl Bussey on 25/06/2014. // Copyright (c) 2014 Carl Bussey. All rights reserved. // #include "FIRFilter.h" using namespace std; using Vamp::FFT; FIRFilter::FIRFilter(const size_t &lengthInput, const size_t &numberOfCoefficients) : m_lengthInput(lengthInput), m_numberOfCoefficients(numberOfCoefficients), m_pFftInput(0), m_pFftCoefficients(0), m_pFftReal1(0), m_pFftImag1(0), m_pFftReal2(0), m_pFftImag2(0), m_pFftFilteredReal(0), m_pFftFilteredImag(0), m_pFftOutputReal(0), m_pFftOutputImag(0) { initialise(); } FIRFilter::~FIRFilter() { cleanup(); } //allocate memory void FIRFilter::initialise() { //next power of 2 m_lengthFIRFFT = pow(2,(ceil(log2(m_lengthInput+m_numberOfCoefficients-1)))); m_pFftInput = new double[m_lengthFIRFFT]; m_pFftCoefficients = new double[m_lengthFIRFFT]; m_pFftReal1 = new double[m_lengthFIRFFT]; m_pFftImag1 = new double[m_lengthFIRFFT]; m_pFftReal2 = new double[m_lengthFIRFFT]; m_pFftImag2 = new double[m_lengthFIRFFT]; m_pFftFilteredReal = new double[m_lengthFIRFFT]; m_pFftFilteredImag = new double[m_lengthFIRFFT]; m_pFftOutputReal = new double[m_lengthFIRFFT]; m_pFftOutputImag = new double[m_lengthFIRFFT]; for(unsigned int i = 0; i < m_lengthFIRFFT; i++){ m_pFftInput[i] = m_pFftCoefficients[i] = m_pFftReal1[i] = m_pFftImag1[i] = m_pFftReal2[i] = m_pFftImag2[i] = m_pFftFilteredReal[i] = m_pFftFilteredImag[i] = m_pFftOutputReal[i] = m_pFftOutputImag[i] = 0.0; } } void FIRFilter::process(const float* pInput, const float* pCoefficients, float* pOutput) { //Copy to same length FFT buffers for(unsigned int i = 0; i < m_lengthFIRFFT; i++){ m_pFftInput[i] = i < m_lengthInput ? pInput[i] : 0.0; m_pFftCoefficients[i] = i < m_numberOfCoefficients ? pCoefficients[i] : 0.0; } FFT::forward(m_lengthFIRFFT, m_pFftInput, 0, m_pFftReal1, m_pFftImag1); FFT::forward(m_lengthFIRFFT, m_pFftCoefficients, 0, m_pFftReal2, m_pFftImag2); //Multiply FFT coefficients. Multiplication in freq domain is convolution in time domain. for (unsigned int i = 0; i < m_lengthFIRFFT; i++){ m_pFftFilteredReal[i] = (m_pFftReal1[i] * m_pFftReal2[i]) - (m_pFftImag1[i] * m_pFftImag2[i]); m_pFftFilteredImag[i] = (m_pFftReal1[i] * m_pFftImag2[i]) + (m_pFftReal2[i] * m_pFftImag1[i]); } FFT::inverse(m_lengthFIRFFT, m_pFftFilteredReal, m_pFftFilteredImag, m_pFftOutputReal, m_pFftOutputImag); //copy to output for (unsigned int i = 0; i < m_lengthInput; i++){ pOutput[i] = m_pFftOutputReal[i]; } } //remove memory allocations void FIRFilter::cleanup() { delete []m_pFftInput; delete []m_pFftCoefficients; delete []m_pFftReal1; delete []m_pFftImag1; delete []m_pFftReal2; delete []m_pFftImag2; delete []m_pFftFilteredReal; delete []m_pFftFilteredImag; delete []m_pFftOutputReal; delete []m_pFftOutputImag; m_pFftInput = m_pFftCoefficients = m_pFftReal1 = m_pFftImag1 = m_pFftReal2 = m_pFftImag2 = m_pFftFilteredReal = m_pFftFilteredImag = m_pFftOutputReal = m_pFftOutputImag = 0; }