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Diffstat (limited to 'libs/qm-dsp/dsp/chromagram/Chromagram.cpp')
| -rw-r--r-- | libs/qm-dsp/dsp/chromagram/Chromagram.cpp | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/libs/qm-dsp/dsp/chromagram/Chromagram.cpp b/libs/qm-dsp/dsp/chromagram/Chromagram.cpp new file mode 100644 index 0000000000..014e37b55f --- /dev/null +++ b/libs/qm-dsp/dsp/chromagram/Chromagram.cpp @@ -0,0 +1,181 @@ +/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ + +/* + QM DSP Library + + Centre for Digital Music, Queen Mary, University of London. + This file 2005-2006 Christian Landone. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. See the file + COPYING included with this distribution for more information. +*/ + +#include <iostream> +#include <cmath> +#include "maths/MathUtilities.h" +#include "Chromagram.h" + +//---------------------------------------------------------------------------- + +Chromagram::Chromagram( ChromaConfig Config ) : + m_skGenerated(false) +{ + initialise( Config ); +} + +int Chromagram::initialise( ChromaConfig Config ) +{ + m_FMin = Config.min; // min freq + m_FMax = Config.max; // max freq + m_BPO = Config.BPO; // bins per octave + m_normalise = Config.normalise; // if frame normalisation is required + + // No. of constant Q bins + m_uK = ( unsigned int ) ceil( m_BPO * log(m_FMax/m_FMin)/log(2.0)); + + // Create array for chroma result + m_chromadata = new double[ m_BPO ]; + + // Create Config Structure for ConstantQ operator + CQConfig ConstantQConfig; + + // Populate CQ config structure with parameters + // inherited from the Chroma config + ConstantQConfig.FS = Config.FS; + ConstantQConfig.min = m_FMin; + ConstantQConfig.max = m_FMax; + ConstantQConfig.BPO = m_BPO; + ConstantQConfig.CQThresh = Config.CQThresh; + + // Initialise ConstantQ operator + m_ConstantQ = new ConstantQ( ConstantQConfig ); + + // Initialise working arrays + m_frameSize = m_ConstantQ->getfftlength(); + m_hopSize = m_ConstantQ->gethop(); + + // Initialise FFT object + m_FFT = new FFTReal(m_frameSize); + + m_FFTRe = new double[ m_frameSize ]; + m_FFTIm = new double[ m_frameSize ]; + m_CQRe = new double[ m_uK ]; + m_CQIm = new double[ m_uK ]; + + m_window = 0; + m_windowbuf = 0; + + return 1; +} + +Chromagram::~Chromagram() +{ + deInitialise(); +} + +int Chromagram::deInitialise() +{ + delete[] m_windowbuf; + delete m_window; + + delete [] m_chromadata; + + delete m_FFT; + + delete m_ConstantQ; + + delete [] m_FFTRe; + delete [] m_FFTIm; + delete [] m_CQRe; + delete [] m_CQIm; + return 1; +} + +//---------------------------------------------------------------------------------- +// returns the absolute value of complex number xx + i*yy +double Chromagram::kabs(double xx, double yy) +{ + double ab = sqrt(xx*xx + yy*yy); + return(ab); +} +//----------------------------------------------------------------------------------- + + +void Chromagram::unityNormalise(double *src) +{ + double min, max; + + double val = 0; + + MathUtilities::getFrameMinMax( src, m_BPO, & min, &max ); + + for( unsigned int i = 0; i < m_BPO; i++ ) + { + val = src[ i ] / max; + + src[ i ] = val; + } +} + + +double* Chromagram::process( const double *data ) +{ + if (!m_skGenerated) { + // Generate CQ Kernel + m_ConstantQ->sparsekernel(); + m_skGenerated = true; + } + + if (!m_window) { + m_window = new Window<double>(HammingWindow, m_frameSize); + m_windowbuf = new double[m_frameSize]; + } + + for (int i = 0; i < m_frameSize; ++i) { + m_windowbuf[i] = data[i]; + } + m_window->cut(m_windowbuf); + + // FFT of current frame + m_FFT->process(false, m_windowbuf, m_FFTRe, m_FFTIm); + + return process(m_FFTRe, m_FFTIm); +} + +double* Chromagram::process( const double *real, const double *imag ) +{ + if (!m_skGenerated) { + // Generate CQ Kernel + m_ConstantQ->sparsekernel(); + m_skGenerated = true; + } + + // initialise chromadata to 0 + for (unsigned i = 0; i < m_BPO; i++) m_chromadata[i] = 0; + + double cmax = 0.0; + double cval = 0; + + // Calculate ConstantQ frame + m_ConstantQ->process( real, imag, m_CQRe, m_CQIm ); + + // add each octave of cq data into Chromagram + const unsigned octaves = (int)floor(double( m_uK/m_BPO))-1; + for (unsigned octave = 0; octave <= octaves; octave++) + { + unsigned firstBin = octave*m_BPO; + for (unsigned i = 0; i < m_BPO; i++) + { + m_chromadata[i] += kabs( m_CQRe[ firstBin + i ], m_CQIm[ firstBin + i ]); + } + } + + MathUtilities::normalise(m_chromadata, m_BPO, m_normalise); + + return m_chromadata; +} + + |