sdrangel/sdrbase/dsp/spectrumvis.cpp

208 wiersze
5.0 KiB
C++

#include "dsp/spectrumvis.h"
#include "gui/glspectrum.h"
#include "dsp/dspcommands.h"
#include "util/messagequeue.h"
#define MAX_FFT_SIZE 4096
#ifndef LINUX
inline double log2f(double n)
{
return log(n) / log(2.0);
}
#endif
MESSAGE_CLASS_DEFINITION(SpectrumVis::MsgConfigureSpectrumVis, Message)
SpectrumVis::SpectrumVis(GLSpectrum* glSpectrum) :
BasebandSampleSink(),
m_fft(FFTEngine::create()),
m_fftBuffer(MAX_FFT_SIZE),
m_logPowerSpectrum(MAX_FFT_SIZE),
m_fftBufferFill(0),
m_needMoreSamples(false),
m_glSpectrum(glSpectrum),
m_mutex(QMutex::Recursive)
{
setObjectName("SpectrumVis");
handleConfigure(1024, 0, FFTWindow::BlackmanHarris);
}
SpectrumVis::~SpectrumVis()
{
delete m_fft;
}
void SpectrumVis::configure(MessageQueue* msgQueue, int fftSize, int overlapPercent, FFTWindow::Function window)
{
MsgConfigureSpectrumVis* cmd = new MsgConfigureSpectrumVis(fftSize, overlapPercent, window);
msgQueue->push(cmd);
}
void SpectrumVis::feedTriggered(const SampleVector::const_iterator& triggerPoint, const SampleVector::const_iterator& end, bool positiveOnly)
{
feed(triggerPoint, end, positiveOnly); // normal feed from trigger point
/*
if (triggerPoint == end)
{
// the following piece of code allows to terminate the FFT that ends past the end of scope captured data
// that is the spectrum will include the captured data
// just do nothing if you want the spectrum to be included inside the scope captured data
// that is to drop the FFT that dangles past the end of captured data
if (m_needMoreSamples) {
feed(begin, end, positiveOnly);
m_needMoreSamples = false; // force finish
}
}
else
{
feed(triggerPoint, end, positiveOnly); // normal feed from trigger point
}*/
}
void SpectrumVis::feed(const SampleVector::const_iterator& cbegin, const SampleVector::const_iterator& end, bool positiveOnly)
{
// if no visualisation is set, send the samples to /dev/null
if(m_glSpectrum == 0)
{
return;
}
SampleVector::const_iterator begin(cbegin);
while (begin < end)
{
std::size_t todo = end - begin;
std::size_t samplesNeeded = m_refillSize - m_fftBufferFill;
if (todo >= samplesNeeded)
{
QMutexLocker mutexLocker(&m_mutex);
// fill up the buffer
std::vector<Complex>::iterator it = m_fftBuffer.begin() + m_fftBufferFill;
for (std::size_t i = 0; i < samplesNeeded; ++i, ++begin)
{
*it++ = Complex(begin->real() / 32768.0f, begin->imag() / 32768.0f);
}
// 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();
Complex c;
Real v;
std::size_t halfSize = m_fftSize / 2;
if ( positiveOnly )
{
for (std::size_t i = 0; i < halfSize; i++)
{
c = fftOut[i];
v = c.real() * c.real() + c.imag() * c.imag();
v = mult * log2f(v) + ofs;
m_logPowerSpectrum[i * 2] = v;
m_logPowerSpectrum[i * 2 + 1] = v;
}
}
else
{
for (std::size_t i = 0; i < halfSize; i++)
{
c = fftOut[i + halfSize];
v = c.real() * c.real() + c.imag() * c.imag();
v = mult * log2f(v) + ofs;
m_logPowerSpectrum[i] = v;
c = fftOut[i];
v = c.real() * c.real() + c.imag() * c.imag();
v = mult * log2f(v) + ofs;
m_logPowerSpectrum[i + halfSize] = 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;
m_needMoreSamples = false;
}
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() / 32768.0f, begin->imag() / 32768.0f);
}
m_fftBufferFill += todo;
m_needMoreSamples = true;
}
}
}
void SpectrumVis::start()
{
}
void SpectrumVis::stop()
{
}
bool SpectrumVis::handleMessage(const Message& message)
{
if (MsgConfigureSpectrumVis::match(message))
{
MsgConfigureSpectrumVis& conf = (MsgConfigureSpectrumVis&) message;
handleConfigure(conf.getFFTSize(), conf.getOverlapPercent(), conf.getWindow());
return true;
}
else
{
return false;
}
}
void SpectrumVis::handleConfigure(int fftSize, int overlapPercent, FFTWindow::Function window)
{
QMutexLocker mutexLocker(&m_mutex);
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;
}