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#include "dsp/spectrumvis.h"
#include "gui/glspectrum.h"
#include "dsp/dspcommands.h"
#include "util/messagequeue.h"
#define MAX_FFT_SIZE 4096
#ifdef _WIN32
double log2f(double n)
{
return log(n) / log(2.0);
}
#endif
SpectrumVis::SpectrumVis(GLSpectrum* glSpectrum) :
SampleSink(),
m_fft(FFTEngine::create()),
m_fftBuffer(MAX_FFT_SIZE),
m_logPowerSpectrum(MAX_FFT_SIZE),
m_fftBufferFill(0),
m_glSpectrum(glSpectrum)
{
handleConfigure(1024, 10, FFTWindow::BlackmanHarris);
}
SpectrumVis::~SpectrumVis()
{
delete m_fft;
}
void SpectrumVis::configure(MessageQueue* msgQueue, int fftSize, int overlapPercent, FFTWindow::Function window)
{
Message* cmd = DSPConfigureSpectrumVis::create(fftSize, overlapPercent, window);
cmd->submit(msgQueue, this);
}
void SpectrumVis::feed(SampleVector::const_iterator begin, SampleVector::const_iterator end, bool firstOfBurst)
{
// if no visualisation is set, send the samples to /dev/null
if(m_glSpectrum == NULL)
return;
while(begin < end) {
size_t todo = end - begin;
size_t samplesNeeded = m_refillSize - m_fftBufferFill;
if(todo >= samplesNeeded) {
// fill up the buffer
std::vector<Complex>::iterator it = m_fftBuffer.begin() + m_fftBufferFill;
for(size_t i = 0; i < samplesNeeded; ++i, ++begin)
*it++ = Complex(begin->real() / 32768.0, begin->imag() / 32768.0);
// apply fft window (and copy from m_fftBuffer to m_fftIn)
m_window.apply(&m_fftBuffer[0], m_fft->in());
// calculate FFT
m_fft->transform();
// extract power spectrum and reorder buckets
Real ofs = 20.0f * log10f(1.0f / m_fftSize);
Real mult = (10.0f / log2f(10.0f));
const Complex* fftOut = m_fft->out();
for(size_t i = 0; i < m_fftSize; i++) {
Complex c = fftOut[((i + (m_fftSize >> 1)) & (m_fftSize - 1))];
Real v = c.real() * c.real() + c.imag() * c.imag();
v = mult * log2f(v) + ofs;
m_logPowerSpectrum[i] = v;
}
// send new data to visualisation
m_glSpectrum->newSpectrum(m_logPowerSpectrum, m_fftSize);
// advance buffer respecting the fft overlap factor
std::copy(m_fftBuffer.begin() + m_refillSize, m_fftBuffer.end(), m_fftBuffer.begin());
// start over
m_fftBufferFill = m_overlapSize;
} else {
// not enough samples for FFT - just fill in new data and return
for(std::vector<Complex>::iterator it = m_fftBuffer.begin() + m_fftBufferFill; begin < end; ++begin)
*it++ = Complex(begin->real() / 32768.0, begin->imag() / 32768.0);
m_fftBufferFill += todo;
}
}
}
void SpectrumVis::start()
{
}
void SpectrumVis::stop()
{
}
bool SpectrumVis::handleMessage(Message* message)
{
if(message->id() == DSPConfigureSpectrumVis::ID()) {
DSPConfigureSpectrumVis* conf = (DSPConfigureSpectrumVis*)message;
handleConfigure(conf->getFFTSize(), conf->getOverlapPercent(), conf->getWindow());
message->completed();
return true;
} else {
return false;
}
}
void SpectrumVis::handleConfigure(int fftSize, int overlapPercent, FFTWindow::Function window)
{
if(fftSize > MAX_FFT_SIZE)
fftSize = MAX_FFT_SIZE;
else if(fftSize < 64)
fftSize = 64;
if(overlapPercent > 100)
m_overlapPercent = 100;
else if(overlapPercent < 0)
m_overlapPercent = 0;
m_fftSize = fftSize;
m_overlapPercent = overlapPercent;
m_fft->configure(m_fftSize, false);
m_window.create(window, m_fftSize);
m_overlapSize = (m_fftSize * m_overlapPercent) / 100;
m_refillSize = m_fftSize - m_overlapSize;
m_fftBufferFill = m_overlapSize;
}
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