void FrequencyPlot::update(int w, int h)
{
m_image.load(w, h, 1);
m_rect = {10, 10, (w | 1) - 40, (h | 1) - 20};
m_width_rcp = 1.0f / float(m_rect.width());
fill(&m_image, Color(0));
for(int x=0; x<m_rect.width(); x++)
{
if(!(x & 1))
{
int xx = x + m_rect.x();
m_image(xx, m_rect.y())[0] = m_image(xx, m_rect.bottom() - 1)[0] = 255;
}
}
float maxfreqlog = log10(maxFreq());
m_min_freq_log = log10(minFreq());
m_freq_range_log = maxfreqlog - m_min_freq_log;
m_freq_range_log_rcp = 1.0f / m_freq_range_log;
int n = 1;
float f = 1.0f;
float df = 1.0f;
for(;;)
{
if(f >= minFreq())
{
if(f >= maxFreq())
break;
int x = (log10(f) - m_min_freq_log) * m_freq_range_log_rcp * m_rect.width();
paintLineAt(x + m_rect.x(), n == 1 ? 127 : 63);
}
n++;
f += df;
if(n == 10)
{
n = 1;
df *= 10;
}
}
paintLineAt(m_rect.x(), 255);
paintLineAt(m_rect.right()-1, 255);
}
bool FFTFeatures::computeFeatures(const VectorFloat &inputVector){
if( !initialized ){
errorLog << "computeFeatures(const VectorFloat &inputVector) - Not initialized!" << std::endl;
return false;
}
//The input vector should be the magnitude data from an FFT
if( inputVector.getSize() != fftWindowSize*numChannelsInFFTSignal ){
errorLog << "computeFeatures(const VectorFloat &inputVector) - The size of the inputVector (" << inputVector.getSize() << ") does not match the expected size! Verify that the FFT module that generated this inputVector has a window size of " << fftWindowSize << " and the number of input channels is: " << numChannelsInFFTSignal << ". Also verify that only the magnitude values are being computed (and not the phase)." << std::endl;
return false;
}
featureDataReady = false;
UINT featureIndex = 0;
IndexedDouble maxFreq(0,0);
Vector< IndexedDouble > fftMagData(fftWindowSize);
for(UINT i=0; i<numChannelsInFFTSignal; i++){
Float spectrumSum = 0;
maxFreq.value = 0;
maxFreq.index = 0;
centroidFeature = 0;
for(UINT n=0; n<fftWindowSize; n++){
//Find the max freq
if( inputVector[i*fftWindowSize + n] > maxFreq.value ){
maxFreq.value = inputVector[i*fftWindowSize + n];
maxFreq.index = n;
}
centroidFeature += (n+1) * inputVector[i*fftWindowSize + n];
spectrumSum += inputVector[i*fftWindowSize + n];
//Copy the magnitude data so we can sort it later if needed
fftMagData[n].value = inputVector[i*fftWindowSize + n];
fftMagData[n].index = n;
}
maxFreqFeature = maxFreq.index;
maxFreqSpectrumRatio = spectrumSum > 0 ? maxFreq.value/spectrumSum : 0;
centroidFeature = spectrumSum > 0 ? centroidFeature/spectrumSum : 0;
if( computeMaxFreqFeature ){
featureVector[ featureIndex++ ] = maxFreqFeature;
}
if( computeMaxFreqSpectrumRatio ){
featureVector[ featureIndex++ ] = maxFreqSpectrumRatio;
}
if( computeCentroidFeature ){
featureVector[ featureIndex++ ] = centroidFeature;
}
if( computeTopNFreqFeatures ){
sort(fftMagData.begin(),fftMagData.end(),sortIndexDoubleDecendingValue);
for(UINT n=0; n<N; n++){
topNFreqFeatures[n] = fftMagData[n].index;
}
for(UINT n=0; n<N; n++){
featureVector[ featureIndex++ ] = topNFreqFeatures[n];
}
}
}
//Flag that the features are ready
featureDataReady = true;
return true;
}
