sdrangel/sdrbase/dsp/fftwengine.cpp

#include <QTime>
#include "dsp/fftwengine.h"

FFTWEngine::FFTWEngine() :
	m_plans(),
	m_currentPlan(nullptr)
{
}

FFTWEngine::~FFTWEngine()
{
	freeAll();
}

void FFTWEngine::configure(int n, bool inverse)
{
	for (Plans::const_iterator it = m_plans.begin(); it != m_plans.end(); ++it)
    {
		if (((*it)->n == n) && ((*it)->inverse == inverse))
        {
			m_currentPlan = *it;
			return;
		}
	}

	m_currentPlan = new Plan;
	m_currentPlan->n = n;
	m_currentPlan->inverse = inverse;
	m_currentPlan->in = (fftwf_complex*)fftwf_malloc(sizeof(fftwf_complex) * n);
	m_currentPlan->out = (fftwf_complex*)fftwf_malloc(sizeof(fftwf_complex) * n);
	QTime t;
	t.start();
	m_globalPlanMutex.lock();
	m_currentPlan->plan = fftwf_plan_dft_1d(n, m_currentPlan->in, m_currentPlan->out, inverse ? FFTW_BACKWARD : FFTW_FORWARD, FFTW_PATIENT);
	m_globalPlanMutex.unlock();
	qDebug("FFT: creating FFTW plan (n=%d,%s) took %dms", n, inverse ? "inverse" : "forward", t.elapsed());
	m_plans.push_back(m_currentPlan);
}

void FFTWEngine::transform()
{
	if (m_currentPlan) {
		fftwf_execute(m_currentPlan->plan);
    }
}

Complex* FFTWEngine::in()
{
	if (m_currentPlan) {
		return reinterpret_cast<Complex*>(m_currentPlan->in);
    } else {
        return nullptr;
    }
}

Complex* FFTWEngine::out()
{
	if (m_currentPlan) {
		return reinterpret_cast<Complex*>(m_currentPlan->out);
    } else {
        return nullptr;
    }
}

QMutex FFTWEngine::m_globalPlanMutex;

void FFTWEngine::freeAll()
{
	for (Plans::iterator it = m_plans.begin(); it != m_plans.end(); ++it)
    {
		fftwf_destroy_plan((*it)->plan);
		fftwf_free((*it)->in);
		fftwf_free((*it)->out);
		delete *it;
	}

	m_plans.clear();
}