annotate src/vamp-sdk/FFT.cpp @ 445:7f7a10bcaff1 vampipe

Single or double-precision FFTs (double in the default build), not both

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Vamp

    An API for audio analysis and feature extraction plugins.

    Centre for Digital Music, Queen Mary, University of London.
    Copyright 2006-2012 Chris Cannam and QMUL.
  
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#include <vamp-sdk/FFT.h>

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>

#if ( VAMP_SDK_MAJOR_VERSION != 2 || VAMP_SDK_MINOR_VERSION != 7 )
#error Unexpected version of Vamp SDK header included
#endif

_VAMP_SDK_PLUGSPACE_BEGIN(FFT.cpp)

#include "FFTimpl.cpp"

namespace Vamp {

void
FFT::forward(unsigned int un,
	     const double *ri, const double *ii,
	     double *ro, double *io)
{
    int n(un);
    Kiss::kiss_fft_cfg c = Kiss::kiss_fft_alloc(n, false, 0, 0);
    Kiss::kiss_fft_cpx *in = new Kiss::kiss_fft_cpx[n];
    Kiss::kiss_fft_cpx *out = new Kiss::kiss_fft_cpx[n];
    for (int i = 0; i < n; ++i) {
        in[i].r = ri[i];
        in[i].i = 0;
    }
    if (ii) {
        for (int i = 0; i < n; ++i) {
            in[i].i = ii[i];
        }
    }
    kiss_fft(c, in, out);
    for (int i = 0; i < n; ++i) {
        ro[i] = out[i].r;
        io[i] = out[i].i;
    }
    Kiss::kiss_fft_free(c);
    delete[] in;
    delete[] out;
}

void
FFT::inverse(unsigned int un,
	     const double *ri, const double *ii,
	     double *ro, double *io)
{
    int n(un);
    Kiss::kiss_fft_cfg c = Kiss::kiss_fft_alloc(n, true, 0, 0);
    Kiss::kiss_fft_cpx *in = new Kiss::kiss_fft_cpx[n];
    Kiss::kiss_fft_cpx *out = new Kiss::kiss_fft_cpx[n];
    for (int i = 0; i < n; ++i) {
        in[i].r = ri[i];
        in[i].i = 0;
    }
    if (ii) {
        for (int i = 0; i < n; ++i) {
            in[i].i = ii[i];
        }
    }
    kiss_fft(c, in, out);
    double scale = 1.0 / double(n);
    for (int i = 0; i < n; ++i) {
        ro[i] = out[i].r * scale;
        io[i] = out[i].i * scale;
    }
    Kiss::kiss_fft_free(c);
    delete[] in;
    delete[] out;
}

class FFTReal::D
{
public:
    
    D(int n) :
        m_n(n),
        m_cf(Kiss::kiss_fftr_alloc(n, false, 0, 0)),
        m_ci(Kiss::kiss_fftr_alloc(n, true, 0, 0)),
        m_ri(new Kiss::kiss_fft_scalar[m_n]),
        m_ro(new Kiss::kiss_fft_scalar[m_n]),
        m_freq(new Kiss::kiss_fft_cpx[n/2+1]) { }

    ~D() {
        Kiss::kiss_fftr_free(m_cf);
        Kiss::kiss_fftr_free(m_ci);
        delete[] m_ri;
        delete[] m_ro;
        delete[] m_freq;
    }

    void forward(const double *ri, double *co) {
        for (int i = 0; i < m_n; ++i) {
            // in case kiss_fft_scalar is float
            m_ri[i] = ri[i];
        }
        Kiss::kiss_fftr(m_cf, m_ri, m_freq);
        int hs = m_n/2 + 1;
        for (int i = 0; i < hs; ++i) {
            co[i*2] = m_freq[i].r;
            co[i*2+1] = m_freq[i].i;
        }
    }

    void inverse(const double *ci, double *ro) {
        int hs = m_n/2 + 1;
        for (int i = 0; i < hs; ++i) {
            m_freq[i].r = ci[i*2];
            m_freq[i].i = ci[i*2+1];
        }
        Kiss::kiss_fftri(m_ci, m_freq, m_ro);
        double scale = 1.0 / double(m_n);
        for (int i = 0; i < m_n; ++i) {
            ro[i] = m_ro[i] * scale;
        }
    }
    
private:
    int m_n;
    Kiss::kiss_fftr_cfg m_cf;
    Kiss::kiss_fftr_cfg m_ci;
    Kiss::kiss_fft_scalar *m_ri;
    Kiss::kiss_fft_scalar *m_ro;
    Kiss::kiss_fft_cpx *m_freq;
};

FFTReal::FFTReal(unsigned int n) :
    m_d(new D(n))
{
}

FFTReal::~FFTReal()
{
    delete m_d;
}

void
FFTReal::forward(const double *ri, double *co)
{
    m_d->forward(ri, co);
}

void
FFTReal::inverse(const double *ci, double *ro)
{
    m_d->inverse(ci, ro);
}

}

_VAMP_SDK_PLUGSPACE_END(FFT.cpp)